ENVIRONMENTAL IMPACT ASSESSMENT (EIA) FIELD DEVELOPMENT PLAN FINAL REPORT. Report: SPDC (b)

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1 Table of Contents The Shell Petroleum Development Company of Nigeria Limited Operator of the NNPC/Shell/Agip/Total Joint Venture ENVIRONMENTAL IMPACT ASSESSMENT (EIA) of BENISEDE CATCHMENT AREA FDP PHASE II FIELD DEVELOPMENT PLAN FINAL REPORT Report: SPDC (b) JUNE, 2005 EIA of Benisede Catchment Area FDP Phase 2 June, 2005 II

2 Table of Contents STATUS PAGE Title: ENVIRONMENTAL IMPACT ASSESSMENT (EIA) OF BENISEDE CATCHMENT AREA FDP PHASE II FIELD DEVELOPMENT PLAN Originator: The Shell Petroleum Development Company of Nigeria limited Author: Approved by: EPG-PN-CFHEV/EPG-PN-CFHLW EPG-PN-TTWC Document Number: SPDC (b) Version: 03 SECURITY: NON-CONFIDENTIAL Change history: Version Date Pages Reason 03 June 2005 Whole Document Incorporation of FMENV Review Panel comments FINAL REPORT EIA of Benisede Catchment Area FDP Phase 2 June, 2005 III

3 Table of Contents TABLE OF CONTENTS TITLE PAGE STATUS PAGE...I TABLE OF CONTENTS.II - VII ACKNOWLEDGEMENT.VIII LIST OF PLATES...IX LIST OF FIGURES..X LIST OF TABLES..XI LIST OF APPENDICES XII LIST OF ABBREVIATION AND ACRONYMS...XIII - XV EIA PREPARERS....XVI EXECUTIVE SUMMARY CHAPTER ONE 1.0 INTRODUCTION...1 of General....1 of The Proponent. 1 of Background Information..2 of EIA Objectives. 2 of EIA Methodology....3 of Legal and Administrative Framework for EIA in Nigeria...5 of Environmental Impact Assessment (EIA) Act....6 of Petroleum Act of 1969, Section 8 (III)....6 of Oil Pipeline Act and Oil & Gas Pipelines Regulations 1958 (Amended 1995)..6 of Mineral Oils Safety Regulations 1963 (Amended 1997)....7 of National Environmental Protection (Effluent Limitations) Regulation (S.I.8) of National Environmental Protection Regulation (S.I.9) of National Environmental Protection (Management of Solid Hazardous Waste Regulation (S.I.15) of EIA Sectoral Guidelines of the Federal Ministry of Environment (FMENV)...9 of 15 EIA of Benisede Catchment Area FDP Phase 2 June, 2005 IV

4 Table of Contents DPR s Requirements for EIA 11 of Forestry Law CAP 51, of Land Use Act of of Delta and Bayelsa States Ministries of Environment 13 of SPDC HSE Policy..14 of Other National and International Legislation and Conventions. 14 of Structure of the Report...14 of Declaration. 15 of 15 CHAPTER TWO PROJECT JUSTIFICATION...1 of General...1 of Project Objectives...1 of Need for the BCA FDP Project Phase of Benefits of the BCA FDP Project.. 2 of Envisaged sustainability of the BCA FDP Project 2 of Social Sustainability..2 of Environmental Sustainability 2 of Economic Sustainability 3 of Project Alternatives.3 of 4 CHAPTER THREE 3.0 PROJECT DESCRIPTION..1 of General..1 of Project Scope.1 of Project Location....1 of The proposed project Overview...2 of Surface Locations.3 of Benisede Field..3 of Akono Field...5 of Opomoyo Field 5 of Proposed Project Design Philosophy...5 of Engineering and Detailed Design.6 of Applicable Standards and Codes...6 of 36 EIA of Benisede Catchment Area FDP Phase 2 June, 2005 V

5 Table of Contents Quality Assurance of Design...7 of Well Trajectory Design 8 of Wellhead Design...8 of Horizontal Wells..8 of CONVENTION DEVIATED WELLS 9 of Casing Design...9 of Well Completion Design...10 of New Well Completion Design/Philosophy of Gas lift Requirement...12 of Production Commingling...13 of Well Safety Enhancement..13 of Drilling Rig Selection. 14 of Mud Systems..15 of Surface Hole (16" for Conventional or 12-1/4" for horizontal).15 of Build Section (8-1/2" for horizontal).15 of Production hole Section (12-1/4" for Conventional wells) 16 of Drain Hole (6").. 16 of Cementation...16 of Waste Management of Project Schedule.17 of Production Operations Plan...19 of Production Facilities of Campaign Operations and Maintenance.27 of Materials and logistics 34 of Production Operations CASHES Aspects..34 of Well Decommissioning/Abandonment...36 of 36 EIA of Benisede Catchment Area FDP Phase 2 June, 2005 VI

6 Chapter Three CHAPTER FOUR 4.0 DESCRIPTION OF ENVIRONMENT 1 of General.. 1 of Description of Existing Environment...1 0f Relief/Topography Studies... 1 of Climate and Meteorology Studies....1 of Air Quality and Noise...6 of Soil, Agriculture and Land Use Studies....7 of Vegetation / Land use 12 of Vegetation profile of Land use types ans Floristic Composition..13 of Plant Species Diversity of the BCA FDP Area...17 of Wild Life / Biodiversity Studies..20 of Aquatic Studies of Sediment Studies of Microbiology Studies.26 of Geology/Hydrogeological Studies of Social and Health Impact Studies of 44 CHAPTER FIVE 5.0 CONSULTATION of General....1 of Consultation for the BCA FDP project...1 of Consultations by the Proponent of Field Consultations by EIA/SIA/EIA Consultants of Identified Stakeholders for the BCA FDP project..2 of Consultation with Regulators for the BCA FDP project. 2 of Consultation with Host Communities for the BCA FDP project....2 of Community Concerns about the BCA FDP project....3 of Community Assistance/Community Development Projects..3 of 3 EIA of Benisede Catchment Area FDP Phase 2 June, of 253

7 Chapter Three CHAPTER SIX 6.0 POTENTIAL AND ASSOCIATED IMPACT ASSESSMENT..1 of General..1 of Principles of Impact Prediction and Evaluation....1 of Impact Assessment Methodology of Screening and Scoping of the Potential Impacts of Potential Impact Evaluation of Detailed Description of Potential Impacts..13 of Rig Mobilisation of Drilling...13 of Drilling fluid and cuttings...14 of Sewage and Sanitary wastes...14 of Accidental Oil Spill of Impact due to Dredging...15 of Impact due to Flowline installation of Gaseous Emissions..15 of Impact on Fishing of Impact due to Well blow-out.. 16 of Beneficial impacts.. 16 of 32 EIA of Benisede Catchment Area FDP Phase 2 June, of 253

8 Chapter Three 6.7 Risk Assessment of Assessment of Hazards of Project Risk Management...18 of Health, Safety and Environmental Management System in the BCA 18 of Modelling...19 of Air Quality Modelling...19 of Surface Water Quality Modelling.24 of Ground Water Modelling..26 of 32 CHAPTER SEVEN 7.0 MITIGATION MEASURES AND ALTERNATIVES of General...1 of Process Monitoring and Control Technology of Impact Mitigation Measures...2 of 8 CHAPTER EIGHT 8.0 ENVIRONMENTAL MANAGEMENT AND COMMUNITY DEVELOPMENT PLAN...1 of General of EMP Objectives....1 of Environmental Monitoring Programmes.. 2 of 18 EIA of Benisede Catchment Area FDP Phase 2 June, of 253

9 Chapter Three 8.4 Environmental Audit....5 of Waste Generation/Management...5 of Waste Characterization /Categorization...5 of Drilling waste (Use drilling mud and cuttings)....5 of Summary of waste management of Produced Water.. 11 of Pseudo-oil-based Muds and Cuttings.11 of Oil Spills of Gaseous Emissions CO 2, CH 4, SO x, NO x, H 2 S, VOCs (including BTEX) of Halons and CFCs of Staff Resourcing and Training of Community Development Plan.. 13 of Decommissioning and Abandonment Plan.18 of 18 CHAPTER NINE 9.0 CONCLUSION.1 of 1 REFERENCES APPENDICES EIA of Benisede Catchment Area FDP Phase 2 June, of 253

10 Chapter Three ACKNOWLEDGEMENT The Shell Petroleum Development Company of Nigeria Limited (SPDC) wishes to acknowledge the opportunity granted it by the government of the Federal Republic of Nigeria through its Agencies, to conduct this Environmental Impact Assessment (EIA) for Benisede Catchment Area Field Development Phase II Project (BCA FDP). We have unequivocally enjoyed the cordial working relationships with the National Petroleum Investment Management Services (NAPIMS), our Joint Venture Partners, Federal Ministry of Environment (FMENV), Department of Petroleum Resources (DPR), Delta and Bayelsa State Governments, Delta and Bayelsa States Ministries of Environment, Burutu and Ekeremo Local Government Councils, the Elders, Chiefs and Youths of the host/pipeline communities. The contributions of BGI Resources Limited, Port Harcourt, commissioned to execute this EIA studies is acknowledged. The efforts of the project Team comprising representatives from various SPDC departments, viz:- Environment (HSW-ENV), Public and Government Affairs (PRW-PAF), Geomatics (DTW-GEM), Area Team C (PCW) and Legal (CLW LIT) are also recognized. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

11 Chapter Three LIST OF PLATES PAGES PLATE 1: A WELLHEAD IN THE STUDY AREA 12 OF 37 Plate 2: Benisede Flowstation 21 of 36 Plate 3: Soil sampling using a hand-held auger 8 of 44 Plate 4. Brass Creek A Major drainage feature in the study area (also showing a palm bush) 12 of 44 Plate 5:A Farmland in the study Area 14 of 44 Plate 6: Farming on dredge-spoil along bank of Bomadi Creek 16 of 44 Plate 7: Tilapia zilli caught at the Benisede Flowstation area 17 of 44 Plate 8: Drilling new groundwater quality monitoring borehole at Opomoyo. 29 of 44 Plate 9: Flushing existing groundwater quality monitoring boreholes at the Benisede flow-station. 30 of 44 Plate 10: Consultation with communities (Ojobo) 33 of 44 Plate 11: Dugout canoes common means of transportation of goods and persons in the study area. 37 of 44 Plate 12: A Typical Shoreline Settlement in the Study Area Peretorugbene 38 of 44 EIA of Benisede Catchment Area FDP Phase 2 June, of 253

12 Chapter Three LIST OF FIGURES TITLE PAGE 1.1: Assessment Pattern 5 of : FMENV EIA Management Procedure 10 of : DPR Flowchart for the EIA Process 12 of : Benisede Catchment Area 2 of : Benisede prospects 3 of : Completion Diagram for Benisede H 4 of : Completion Diagram for Benisede C and C* 11of : Benisede Phase 2 project Plan 18 of : Schematic Representation of Potential Impact Assessment Approach 2 of : Benisede Catchment Area Flare Emission Dispersion Model 23 of : Oil Spill Fate on Water Surface within Benisede 26 of : Groundwater Flow Direction Model from a Point source 30 of : Impact Flow Direction Model from a Point source 32 of 32 EIA of Benisede Catchment Area FDP Phase 2 June, of 253

13 Chapter Three TITLE LIST OF TABLES PAGE 3.0: The Current Status of BCA Wells and Safety Plans 14 of : Current Benisede Field Completion Data 20 of : Main Maximum Temperature in 0 C 3 of : Monthly Total Rainfall Records in mm 4 of : Mean Monthly Temperature and Rainfall Records 5 of : Wind Speed and Direction within BCA FDP Area (Dry Season) 6 of : Particle Size Distribution in Soil of BCA FDP Area 9 of : Agricultural Landuse types with commonest plant species 15 of : Plant Species diversity and agricultural landuse 18 of : List of Plant Species/disease analysis within BCA FDP Area 19 of : List of Wildlife Species within BCA FDP Area 21 of : A list of the commonest fish Species within the BCA FDP Area 24 of : BCA Community Population 31 of : Demographic profile of the BCA FDP Area 32 of : Family Size Distribution of Communities within BCA FDP Area 32 of : School Enrolment Statistics of : Health Risk Exposure Matrix (health Sensitivities 42 of : Environmental Components and Potential Impact Indicators 6 of : Potential and Associated Impact Identification Checklist 8 of : Impact Evaluation Matrix for BCA FDP 12 of : SPDC HSE Risk Matrix 17 of : Summary of emissions from the proposed flowstation 20 of : Maximum Concentrations for Selected Periods (hours) 24 of : Flow rate (current), Width and Depths across Creeks and Creeklets 25 of : Overburden Longitudinal Conductance and the Protective Capacity 31 of : Classification of Soil Resistivity in Terms of the Corrosivity 31 of : Proffered Mitigation Measures 3 of 8 8.1: Monitoring Programme for Environment Components 3 of : Drilling Discharge Monitoring Programme (DPR Requirement) 4 of : Produced water treatment systems 10 of : Stakeholder Register 16 of 20 EIA of Benisede Catchment Area FDP Phase 2 June, of 253

14 Chapter Three 8.5: Completed and On-going CA/CD Projects 17 of : Current CA/CD projects Plan Summary. 19 of 20 EIA of Benisede Catchment Area FDP Phase 2 June, of 253

15 Chapter Three LIST OF APPENDICES Appendix I: Maps Appendix II: Field Methodologies Appendix III: Recorded Data Table 4.1: Ambient Air Quality Measurements...1 of 1 Table 4.2: Noise Level and Radiation Measurements.1 of 1 Table 4.3: Physico-Chemical Characteristics of soil..1 of 2 Table 4.3c: Texture Analysis of Soil from Benisede field 1 of 1 Table 4.4: Plant Tissue Analysis.1 of 1 Table 4.5: Table 4.6: Table 4.7: Table 4.8: Table 4.9: Physico-Chemical Characteristics of surface water..1 of 3 Physico-Chemical Characteristics of sediment...1 of 2 Summary of Heterotrophic and Petroleum Degrading Bacterial count in soil 1 of 1 Summary of Heterotrophic and Petroleum Degrading fungal count in soil.1 of 1 Microbial analysis of surface water samples (Bacterial) 1 of 1 Table 4.10: Microbial Analysis of surface water samples (Fungal)..1 of 1 Table 4.11: Microbial Analysis of sediment samples (Bacterial)..1 of 1 Table 4.12: Microbial Analysis of sediment samples (Fungal).1 of 1 EIA of Benisede Catchment Area FDP Phase 2 June, of 253

16 Chapter Three Appendix IV: Detailed Environmental Legislation and Conventions Appendix V: Evidence of Consultations EIA of Benisede Catchment Area FDP Phase 2 June, of 253

17 Chapter Three LIST OF ABBREVIATIONS AND ACRONYMS ALARP ANSI APHA ASME cfu/g cfu/ml cm C Ca CAO CEC Cl Cu CO CO 2 COD CPF DEP DPR E EGASPIN E & P EIA ESS FMENV FAO GC GPS GSI GTS HAZOP HEMP As Low As Reasonably Possible American National Standards Institute American Public Health Association American Society of Mechanical Engineers Colony forming unit per gram Colony forming unit per millilitre Centimetre Carbon Calcium Computer Assisted Operations Cation Exchange Capacity Chloride Copper Carbon monoxide Carbon dioxide Chemical Oxygen Demand Central Processing Facility Design and Engineering Practice Department of Petroleum Resources East Environmental Guidelines and Standards for the Petroleum Industry in Nigeria Exploration and Production Environmental Impact Assessment Expandable Sand Screen Federal Ministry of Environment Food and Agricultural Organization Gas Chromatograph Global Positioning System Gonadosamatic Indices Gas Transmission System Hazard and operability Hazards and Effects Management Process EIA of Benisede Catchment Area FDP Phase 2 June, of 253

18 Chapter Three HNO 3 HP HSE HUB HUF H 2 SO 4 km m mg/kg mg/l ml MMb MMstb mm MPF ms -1 ms/cm mv N NAPIMS NNPC NE NIOMR NOx NTU NW OHGP o C PAH ph ppm ppt S SE Trioxonitrate (V) acid High Pressure Health, Safety & Environment Hydrocarbon Utilizing Bacteria Hydrocarbon Utilizing Fungi Tetraoxosulphate (VI) acid kilometres metres milligram per kilogram milligram per litre millilitre Million Metric Barrels Million Metric Standard barrels milimetre Mobile Production Facility metres per second Milli Siemens per centimetre millivolt North National Petroleum Investment Management Services of the NNPC Nigerian National Petroleum Company North East Nigerian Institute of Oceanography and Marine Research Nitrogen Oxides Nathalometric Turbidity Unit North West Open Hole Gravel Pack Degree Celsius Poly Aromatic Hydrocarbon Hydrogen ion concentration Parts per million Parts per thousand South South East EIA of Benisede Catchment Area FDP Phase 2 June, of 253

19 Chapter Three sp species SPDC Shell Petroleum Development Company of Nigeria Limited SPM Suspended Particulate Matter SSW South South West Stb Standard barrels SW South West SFAGG South Forcados Associated Gas Gathering SSAGG Southern Swamp Associated Gas Gathering STABOR Computer Programme for well bore stability TFC Total Fungal Count TDS Total Dissolved Solid THBC Total Heterotrophic Bacterial Count THC Total Hydrocarbon Content UR Undeveloped Reserve VOC Volatile Organic Carbon W West % Percentage < Less than EIA of Benisede Catchment Area FDP Phase 2 June, of 253

20 Chapter Three EIA PREPARERS DR. IME UDOTONG - (TEAM LEADER) MICROBIOLOGY & WASTE MANAGEMENT DR AFAM ANENE - FISHERIES/HYDROBIOLOGY DR. K. E. AKPABIO - VEGETATION/WILDLIFE/BIODIVERSITY Dr. S. O Edem - Soil Sampling/Land use Mr. Fidelis Effiom - Geology/Hydrogeology Dr. V.O Ebong - Social Impact Assessment (SIA)/ Health Impact ASSESSMENT (HIA) MR. M. ONUORA - GEO-POSITIONING (DTW-GEM) LABORATORY ANALYSIS - TECHNOLOGICAL PARTNERS INTERNATIONAL LABORATORIES LIMITED (TPI) TECHNICAL REVIEW MR. BASSEY AKPAN DR. IME UDOTONG HSW-ENV (SPDC) REPRESENTATIVES Dr. A.G. Yammama (Team Leader) Miss. Sophia Samuel DR. D.P.O. AGUIYI Mr. Stephen Akeno Phase Two: Report Review Team EIA of Benisede Catchment Area FDP Phase 2 June, of 253

21 Chapter Three Miss. Sophia Samuel Mr. Ubom Archie (Project Engineer) Mr. Akeno Steve Mr. Wale Adesanya Mr. Iyegoa Igali EIA of Benisede Catchment Area FDP Phase 2 June, of 253

22 Chapter Three EXECUTIVE SUMMARY Introduction Shell Petroleum Development Company (SPDC) intends to further develop the Benisede Catchment Area (BCA) Field. The field development is aimed at boosting oil output and to also test neighbouring prospects. The Benisede Catchment Area (BCA) Field Development Plan (FDP) Phase 2 covers the lifecycle re-development plan of the Benisede Catchment Area i.e. Benisede field and prospects as well as Akono, Opomoyo, Osuopele and Orubou fields. The plan presents a base case development scenario targeting MMstb of reserves through the drilling of about 11 wells. An Environmental Impact Assessment for the project has been carried out in accordance with the requirement of Nigerian legislation and SPDC HSE policy. Legal and Administrative Framework The Benisede Catchment Area Field Development Project shall be executed within the premise of the relevant Nigerian regulatory laws and statutes, international conventions and SPDC policies. These include: Acts, Regulations, Guidelines and Standards for the petroleum industry sector. Design and Engineering practices and SPDC standards. International conventions and treaties to which Nigeria is signatory. Details of the applicable laws, regulations and standards are provided in section 1.6 of this report. The EIA Objectives The objectives of the EIA study are: to determine the baseline ecological conditions of the study area; to determine the environmental sensitivities prevalent in the area; to identify, evaluate, and predict the impact of the project on the ecological, socioeconomic and cultural settings with adequate interfacing and project interaction; EIA of Benisede Catchment Area FDP Phase 2 June, of 253

23 Chapter Three to identify health hazards that may result from the different phases of the project and evaluate local population exposure to these hazards. to develop control strategies with a view to mitigating and ameliorating significant impacts that the project would have on the totality of measurable environmental characteristics; to develop a cost effective Environmental Management Plan (EMP) for the identified impacts. Consultation SPDC shall maintain the established communication and consultation links with Regulatory Agencies and other stakeholders (Host and Pipeline Communities as well as NGOs). Project Overview The Benisede Catchment Area (BCA) Field which is in the swamp, was discovered in 1973, and based on recent 3-D seismic survey, there are plans to drill more wells in the field. The BCA Field is a three-in-one field comprising Benisede, Akono and Opomoyo fields. The objective of the proposed project is to develop the remaining reserves in these fields and test neighbouring exploration prospects. The proposed phase 2 project, shall be carried out in the Southern Swamp Area of the Western Division of SPDC, and would involve the drilling of about 11 wells and laying about 60km of flowlines to an upgraded Benisede flowstation. It is envisaged that about Hectares of land will be taken for the project, which will also involve dredging activities. About 184 weeks will be spent on the proposed project, i.e. 24 weeks on the flowline and jacket construction phase and about 160 weeks on the drilling activities. The well drilling phase of the project will require about 100 men on site. Project Alternatives Three (3) possible integrated development alternatives/scenarios were identified: Scenario 1: No Action/Do nothing Scenario 2: Development activity with upgraded 90 Mbpd facility EIA of Benisede Catchment Area FDP Phase 2 June, of 253

24 Chapter Three Scenario 3: Development activity with new 90 Mbpd facility Scenario 3 is the preferred alternative given its economic advantages and environmental implications. This Green Field alternative gives opportunity for an integrated oil and gas facility, and thus incorporates SPDC s new operational philosophy of integrated oil and gas operations. The scenario is also in line with the Federal Government s flares down policy. Scenario 3 is therefore an environment friendly alternative. Project Schedule The BCA FDP Phase II drilling was originally scheduled to start in 2005 but is now delayed because of alignment required with the Southern Swamp Integrated Oil and Gas Project (SSIOGP) to harness the expected Associated Gas (AG) to the Liquefied Natural Gas (LNG) train in line with the flares out date of Well Decommissioning/Abandonment All wells that have no economic value will be decommissioned and abandoned in line with SPDC Well Abandonment Policy. On reaching the end of the project life span, a decommissioning team shall be set up to plan and implement the guidelines for decommissioning/abandonment to ensure that the best and practicable methods available are employed to clean up the project site. Environmental Status The environmental characteristics of the proposed project area as indicated by the various ecological components have been carefully studied through existing maps, meteorological reports, baseline reports and detailed field study. CLIMATE AND METEOROLOGY The study area is located in the Gulf of Guinea and lies in the semi-hot equatorial zone and with distinct climatic seasons, wet and dry. The climate in the area is typical of the equatorial rain forest with temperatures ranging between o C and EIA of Benisede Catchment Area FDP Phase 2 June, of 253

25 Chapter Three o C for wet and dry seasons respectively. Humidity in the area is high all the year round. Two main winds, southwest (SW) and the northeast (NE) winds are generally influential on the weather in the study area. However, a third wind, the North-South wind has also been reported in the area. The north south wind is known to be strongest during the dry season (November March). It accounts for about 32% of the annual winds within the Niger Delta area during this period. (NLNG, 1997). Within the BCA FDP area, rain falls throughout the year but over 80% of it occur in the months of May to September. The 25-year rainfall records ( ) from the Port Harcourt station indicate a mean rainfall of 373mm, 19.3 and 107.9mm for the months of July, December and March respectively. The single highest rainfall record is 840.9mm recorded in July Air Quality Ambient Air Quality measurements taken for various parameters within the proposed project area indicate that the values were generally within FMENV permissible limits. The ranges for the various parameters are as follows, ppm for NO x, ppm for SO x,, ppm for VOC, ppm for CO 2 and < ppm for CO. Ambient noise levels within the study area ranged from 52.5 db (A) at Ojobo primary school to 93.5 db (A) at the flare site. These values were within FMENV, DPR and OSHA permissible exposure limits. DPR s EGASPIN 2002 stipulates a maximum noise level of 90dBA per 8-hours, for unprotected ears. Vegetation The vegetation of BCA FDP area is generally homogenous and composed mostly of two layers of vegetation strata, namely the tree and shrub/herb layers. The tree layer is composed mostly of pure stands of Raphia hookeri with only scattered freshwater swamp forest tree species. The vegetation also consists of emergent tree species EIA of Benisede Catchment Area FDP Phase 2 June, of 253

26 Chapter Three reaching up to 15 metres in some cases. The Vegetation cover is between 60-80%, with patches of bushes resulting from farming activities (newly cleared farm plots, cultivated farmlands and abandoned or fallow farm plots). Drainage Two major water bodies viz, Bomadi and Brass Creeks drain the study area. A few other creeklets also aid the drainage of the area. Regional Geology/Geomorphology The Niger Delta complex generally consists of Cenozoic formations deposited in a high energy regime. The region is a constructive deltaic environment and can be divided into Continental Benin, Paralic Agbada and Pro-Delta Marine Akata formations. The geomorphology of the land is dominated by an almost flat terrain that is only few meters above mean sea level. Depressions and a few minor undulations that are perennially flooded also occur in the area. Physico-chemistry The soils are acidic, with mean ph values of 5.4 and 5.2. The mean concentrations of CEC were 6.43 and 6.33 meq/100g for surface and subsurface soils respectively. The low CEC indicates low soil fertility. Mean values for nitrogen were and percent for surface and subsurface soils respectively while the concentration of phosphate ranged from ppm. The distribution of these nutrients showed a general decline with depth of the soils as the topsoil usually recorded higher values. The concentration of heavy metals in soils was generally trace to low. There was no significant variation in the nutrient level for both wet and dry seasons. The fungal counts of soil samples of the BCA FDP area were low and ranged between 1.0 x 10 4 to 3.5 x 10 7 cfu/mg. The count of total heterotrophic bacteria for water were found to range from 1.3x x cfu/g with a percentage hydrocabon biodegraders range of nil to 2.1% in the dry season. The data obtained suggest that there was very little seasonal variation EIA of Benisede Catchment Area FDP Phase 2 June, of 253

27 Chapter Three in the actual microbial counts. The predominant bacterial communities in the soil samples of the BCA FDP area were composed of Pseudomonas sp, Proteus sp; Micrococcus sp; Bacillus sp; Eschericha sp; Klebsiella sp. The relatively low concentrations of hydrocarbon degrading bacteria and fungi are indicative of the insignificant pollution status of the environment. The results of physico-chemical analysis for the surface waters of the area reflect a typical swamp environment. In-situ measurements of the temperatures of the surface water within the BCA FDP area ranged from 21.8 to C with a mean of C. Turbidity values varied between 2.1NTU and 56.0 NTU. Total dissolved Solids varied from 30.5 to 110.8mg/l and electrical conductivity values were between 26.7 and 99.2mg/l. The ph values indicated a weak acidic range of while bicarbonate values ranged from 0.56 to 3.31mg/l. The chloride concentrations varied from 26.8 to 99.2mg/l. Chemical Oxygen Demand (COD) values ranged from 3.7mg/l to 15.3mg/l. Dissolved Oxygen values ranged from 4.42 to 5.09mg/l while Biochemical Oxygen Demand (BOD) values ranged from 0.85 to 1.21mg/l. The concentrations of Na +, K +, Ca ++, and Mg ++ ions are as follows: 2.51mg/l to 5.74mg/l; 1.87mg/l to 8.74mg/l; 4.87mg/l to 27.29mg/l and 1.83mg/l to 4.34mg/l respectively. The heavy metal concentrations were generally low. The concentrations of Total Hydrocarbon Content (THC) of the surface water were also low (<0.50mg/l). Plankton Studies The phytoplankton community of the surface water within the BCA FDP area comprised of 32 taxa belonging to the Divisions Bacillariophyta (16 species); Chlorophyta (6 species); Cyanophyta (3 species) and Euglenophyta (7 species). The diatoms (Bacillariophyta) were the most prevalent followed by the Euglenoids while Microcystis (Cyanophyta) was the most dominant blue-green species present in all the stations in the BCA FDP area. The zooplankton community of the surface water within the BCA FDP area was mainly arthropods and rotifers. The arthropods were made up of cladocera, EIA of Benisede Catchment Area FDP Phase 2 June, of 253

28 Chapter Three Conchostraca, Ostracoda and Copepoda. Bosmina longirostris and Bosminopsis dietersi were prevalent among the cladocerans. The Ostracoda was represented by Parastenocypris sp, Stenocypris sp and Cypridopsis. The Cyclopoids were dominant among the copepods. The Rotifera were represented by five families and eleven species dominated by members of the family Brachionidae. Agriculture Agriculture in the area is dictated by, climatic factors, soil properties and landscape features of the coastline. The locals in the BCA FDP area are mainly subsistence farmers and often practice mixed cropping. Crop combinations include cassava, yams, vegetables, maize and okra. Plantain, banana and cocoyam are also cultivated in the area. However, plantain and banana are observed to be scattered around the bushes while cocoyam is commonly planted on dredged materials along the banks of the creeks. Although the crops are cultivated in small scale in the area, they were observed to be flourishing, indicating the suitability of the soil for such crops. Fisheries Fishing within the BCA FDP area is usually carried out using fishing gears such as fish traps, conical baskets, hooks and lines, cast nets, sweep nets and drag nets of various mesh sizes. Shellfishes within the area include prawns of the families Atyidal and palaemomidal and the commercially important bivalve mollusc (Egeria paradoxa) which were mostly picked up by divers operating from dug-out canoes along the Bomadi and Brass creeks. Fish observed in their natural environment or bought from the fishermen operating along the creek belonged to the orders Characiformes, Cypriniformes, Osteoglossiformes, Siluriformes and Perciformes. Socio-economics The BCA FDP covers a number of communities in Bayelsa and Delta States. These include Ojobo, in Burutu Local Government Area of Delta State and Tamogbene, Peretorugbene, Oweigbene, Norgbene and Amabolou in Ekeremor Local Government Area in Bayelsa State. The estimated population of the communities within the BCA FDP area is 37,468 (1991 population census) people. Some of the communities within the BCA FDP area studied include Ojobo (7,204 people), Peretorugbene (9,037 people), Tamogbene (375 EIA of Benisede Catchment Area FDP Phase 2 June, of 253

29 Chapter Three people), Amabolu (4,778 people), Norgbene (2,401 people) and Ekeremor (10,393 people). The literacy level in the study area is relatively high especially in the two main communities Ojobo and Peretorugbene. There are a total of 11 primary and 5 secondary schools, which are evenly spread within the area. The two major BCA landlord communities, Peretorugbene and Ojobo, are homogeneously Ijaw, a major ethnic group in the Niger Delta region. The locals are predominantly fishermen, a small fraction however engage in crop farming. About 27% of residents within the BCA FDP area earn over N2000 weekly from fishing while 42% earn less than N500. Over 30% of residents within the BCA FDP area earn less than N5000 weekly from other sources including farming. Health Status Health facilities were generally lacking in the area, even where health centres existed, they lacked equipment and drugs. Most residents in the area depend on the patent medicine store dealers doctors for medical attention. History and physical examination of the sampled population in the communities surveyed revealed certain morbidity characteristics. They include, fever/frequent headache, Blurred vision, Diarrhoea and vomiting, Skin rashes, Marked weight loss, Cough and Catarrh. From interviews conducted and records from health centers, there was no reported case of HIV/AIDS in the area. Potential Impact Assessment The assessment of the degree of alteration to natural conditions due to the project activities were carried out using the modified Leopold interaction matrix. The overall potential negative impacts of the project activities on the environment are minimal. Site preparation, drilling, dredging and flowline laying are some activities, which would adversely affect the environment. However, these negative impacts will be minimal, localised and short-term particularly given the fact that the adverse impacts will be properly mitigated with the EIA of Benisede Catchment Area FDP Phase 2 June, of 253

30 Chapter Three strict implementation of the Environmental Management Plan developed for the proposed project. Consequently, the long-term beneficial impact of the proposed project makes it more beneficial than adverse. MITIGATION AND AMELIORATIVE MEASURES To ensure the successful execution of the BCA FDP project, SPDC shall apply the following measures: Ensuring that vegetation cutting / clearing activities are reduced to the barest minimum. The cutting of vegetation outside the designated areas and creation of access routes into the forest shall be prohibited. Effective journey management shall be applied (transport of heavy duty equipment and pipes during peak traffic period shall be avoided) HSE training and job hazard analysis shall be conducted to ensure that all staff observes safety rules at work places. SPDC shall identify the locations of burial sites and shrines to avoid damage during construction Exposure to high noise equipment shall be restricted to the recommended 8-hour a day limit SPDC shall maintain fuel combustion engines at optimal operating conditions to reduce emissions of exhaust gases. Routine inspection of wellheads and other facility shall be maintained to ensure facility integrity. SPDC shall regularly conduct monitoring of the project environment using an environmental monitoring plan. Excavation and other activities that may result in the alteration of the landscape and condition of the land cover shall be limited. SPDC shall manage wastes generated in accordance with regulatory requirements and standard practices. SPDC shall keep to the operational lifespan of the project. Appropriate warning signs shall be used to alert residents of the presence of machines/equipment at abandonment and decommissioning. SPDC shall embark on community development programmes in line with the desires and needs of the people. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

31 Chapter Three SPDC shall activate her oil spill contingency plans to minimize impacts of oil spills and leaks on ponds, creeks and rivers. Environmental Management Plan The Environmental Management Plan (EMP) for the proposed BCA FDP incorporates various mitigation measures to ensure that adverse impacts associated with the development of the BCA field are reduced to As Low As Reasonably Practicable (ALARP) levels. The EMP addresses waste management, environmental audit and environmental monitoring programmes of the BCA FDP. Waste management plan for the BCA FDP is targeted primarily at waste minimisation, waste reuse and recycling such as, reuse and recycling of drilling mud. The plan has taken into consideration, waste elimination by designing out unnecessary waste generating modules and incorporating waste reduction opportunities such as drilling of slim holes, use of slim width dredging, clearing of slim Right of Ways (ROWs) and cluster drilling. Processes already exist to measure and record quantity of waste generated. Environmental audit will be conducted on a regular basis for all operations facilities throughout the life span of the BCA FDP project. The Environmental Monitoring Programmes for the proposed project, which shall cover environmental components and discharge types, shall comply with DPR/FMENV regulatory requirements. Conclusion The EIA of the BCA FDP indicates that the environmental components that are likely to be adversely impacted are vegetation, water quality, fisheries /wildlife, macrophytes and benthos. There is also the likelihood of direct impact on human population within the project area in terms of health and socio-economic well being. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

32 Chapter Three However, this EIA report has developed a well articulated Environmental Management plan to reduce the adverse impacts of the project on the environment to as low as reasonably possible levels. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

33 Chapter Three CHAPTER ONE 1.0 INTRODUCTION 1.1 General Shell Petroleum Development Company of Nigeria Limited (SPDC) proposes to further develop the Benisede Catchment Area (BCA) Field. The field development is aimed at boosting oil output and to also test neighbouring prospects. The Benisede Catchment Area (BCA) Field Development Plan (FDP) phase 2 covers the lifecycle re-development plan of the Benisede Catchment Area i.e. Benisede field and prospects, as well as Akono, Opomoyo, Osuopele and Orubou fields. The plan presents a base case development scenario targeting MMstb of reserves through the drilling of about 11 wells. 1.2 The Proponent Shell Petroleum Development Company of Nigeria Limited (SPDC) is a major Oil & Gas exploration and production (E & P) Company in Nigeria. It operates a joint Venture Partnership with Nigerian National Petroleum Corporation (NNPC), ELF Petroleum Nigeria Ltd (EPNL) and Nigerian Agip Oil Company (NAOC). The partnership participation are 55%, 30%, 10% and 5% for NNPC, SPDC, ELF and NAOC, respectively. SPDC first discovered oil in commercial quantities in Nigeria in 1956, although it had been operating in Nigeria since The company finally adopted the name Shell Petroleum Development Company of Nigeria Limited in 1978 after previously changing its name from Shell D Arcy to Shell-BP. The company has 92 producing oil fields. These fields, including the BCA Field, are located in the Sedimentary basin of the Niger Delta region with a production potential of over one million barrels of oil per day (about 50% of Nigeria s Oil production capacity), the SPDC is the largest Oil exploration and Production company in Nigeria. 1.3 Background Information EIA of Benisede Catchment Area FDP Phase 2 June, of 253

34 Chapter Three The BCA field was discovered in 1973 with 17 hydrocarbon-bearing reservoirs and the only flowstation in the area was commissioned in Currently, 20 wells are tied into the flowstation producing from 3 fields. Two other adjacent fields, Akono and Opomoyo, were discovered and tied into the Benisede station in 1996 to make up the Benisede Catchment Area (BCA). Crude evacuation from the field is via the 16 South Forcados Trunkline connecting to the Trans Ramos Trunkline, which terminates at the Forcados Terminal. The field covers an area of about 16 sq. km. The estimated land-take within Benisede field is Ha and is accessible by air and water. A flight journey from Industrial Area (where all SPDC transportation facilities e.g. boats, helicopters, cars, trucks, etc. are based) to Benisede takes about 28 minutes while a boat takes about 3 hrs. There is a helipad equipped with lights, and a jetty that serves the Flowstation, which has a capacity of 60,000bpd and a total of 24 wells (22 in Benisede, 1 in Akono and 1 in Opomoyo) out of which, 20 are producing (i.e. 18 in Benisede and 1 each in Akono and Opomoyo) with all the flowlines buried. Recent studies show an undeveloped oil reserve, which stands at about 63% of remaining reserves. Consequently, the plan to redevelop the BCA field is aimed at exploiting these undeveloped reserves. SPDC has carried out this EIA in order to comply with all relevant statutory requirements as well as ensure that its operations in respect of the BCA FDP are within the principles of sustainable development. Consequently, the EIA process has systematically evaluated the environmental consequences of the proposed project and also proffered mitigation measures for adverse impacts identified. This report will therefore serve as the basis for communication to obtain relevant approvals from regulatory agencies i.e. FMENV and DPR, and also to satisfy public information needs on the BCA FDP project. 1.4 EIA Objectives The objectives of the EIA study include the following: to determine the baseline ecological conditions of the study area; to determine the environmental sensitivities prevalent in the area; EIA of Benisede Catchment Area FDP Phase 2 June, of 253

35 Chapter Three to identify, evaluate, and predict the impact of the project on the ecological, socio-economic and cultural settings with adequate interfacing and project interaction; to identify health hazards that may result from the different phases of the project and evaluate local population exposure to these hazards. to develop control strategies with a view to mitigating and ameliorating significant impacts that the projects would have on the totality of measurable environmental characteristics; to develop a cost effective Environmental Management Plan (EMP) for the impacts identified. 1.5 EIA Methodology The EIA study of the proposed Benisede Catchment Area FDP was carried out in accordance with the Federal Ministry of Environment (FMENV) Procedural and Sectoral Guidelines 1995, the Department of Petroleum Resources (DPR) EGASPIN, 2002 and the new SPDC EIA Manual. The study involved a blend of a multidisciplinary team and standard methods from pure science, engineering, social and health sciences in order to obtain basic data for impact identification and establishment of mitigation and amelioration measures. The study generally involved desktop studies, field research, consultation, impact assessment and proffering of mitigation measures and development of an environmental management plan (EMP). Desktop Studies Desktop studies were undertaken to acquire information on climate, geology, soil, vegetation, socio-economics, and other environmental components of the proposed Benisede Catchment Area FDP. The materials consulted include textbooks, articles, and previous study reports on the proposed project area e.g. the Benisede Catchment Area FDP Baseline Study Report (Dec., 2002), charts, articles, and maps. Field Research A field research was used to harmonize and verify information gathered from desktop studies and also fill data gaps identified. The fieldwork was carried out in line with the FMENV Procedural Guidelines (1995) and DPR Guidelines and Standards for Petroleum Industry in Nigeria (Draft Revised Edition 2002) whilst maintaining SPDC EIA of Benisede Catchment Area FDP Phase 2 June, of 253

36 Chapter Three HSE and QA/QC standards. The data gathered from the field investigation were used in determining relevant baseline ecological, socio-economic and health conditions of the proposed project area. Consultation Consultation was carried out with the proposed project stakeholders (FMENV, Delta and Bayelsa States Ministry of Environment, communities and NGOs). Some of these were consulted during the scoping stage, prior to the start of the field campaign. This was done to ensure that the views and opinions of all stakeholders regarding the proposed project and its associated and potential impacts are integrated into the EIA. Potential Impact Assessment and Mitigation A combination of modified Leopold matrix and the checklist methods were adopted in assessing the potential and associated impacts of the proposed project. The FMENV EIA Sectoral Guidelines for Oil and Gas Industry Projects as well as the environmental baseline and socio-economic status of the project area and other references were used to identify and evaluate the potential and associated impacts of the proposed project and also to proffer appropriate mitigation measures. This was carried out in an interactive manner as shown in Figure 1.1 EIA of Benisede Catchment Area FDP Phase 2 June, of 253

37 Chapter Three Scoping & identifying Issues Avoidance Mitigation Monitoring & Follow up Evaluating Impact Significance Predicting Impacts Recommendations on base resource requirement, availability of manpower / technology and public acceptance Figure 1.1: Assessment Pattern Professional judgment, knowledge of the ecosystem where the project will be located, experience on similar projects and consensus of opinions of experts/consultants were used in determining the appropriate impact mitigation measures/ EMP. 1.6 Legal and Administrative Framework for EIA in Nigeria The EIA of the proposed BCA FDP was carried out in accordance with regulations, guidelines and standards of the Federal Ministry of Environment and the Department of Petroleum Resources, State legislations on the environment and all other applicable National legislations, and International Agreement and Convention to which Nigeria is a signatory. The EIA is also in conformity with all SPDC HSE policies Environmental Impact Assessment (EIA) Act EIA of Benisede Catchment Area FDP Phase 2 June, of 253

38 Chapter Three The Environmental Impact Assessment (EIA) Act (Act No. 86 of 1992) makes EIA mandatory for all new major public and private projects in Nigeria. The EIA Act sets out to: (i) Consider the likely impacts, and the extent of these impacts on the environment before embarking on any project or activity. (ii) Promote the implementation of appropriate policy in all federal lands consistent with all laws and decision-making processes through which the goal of this Act may be realized. (iii) Encourage the development of procedures for information exchange, notification and consultation between organizations and persons when the proposed activities are likely to have significant environmental effects on boundary or trans-state or on the environment of bordering towns and villages The EIA Act gives specific powers to the Federal Environmental Protection Agency, FEPA (now FMENV) to facilitate environmental assessment of projects. In September 1995, FEPA published the EIA Sectoral Guidelines for Oil and Gas Industry projects. The guidelines are intended to assist in the proper and detailed execution of EIA of oil and gas projects in consonance with EIA Act of Petroleum Act 1969, Section 8(III) The Petroleum Act of 1969 makes provision for the prevention of pollution of watercourses and the atmosphere during petroleum operations Oil Pipeline Act And Oil & Gas Pipelines Regulations 1958 (Amended 1995) These Acts regulate the right to establish, maintain and operate oil pipelines and ancillary facilities in Nigeria. The Acts require that applications for permit to survey an oil pipeline route be submitted to the Minister for Petroleum Resources. Upon completion of the survey, the holder of a permit to survey may apply to the Minister of Petroleum Resources for an Oil Pipeline License, subject to the payment of the prescribed fees. The license shall entitle the holder to enter and take possession or use a strip of land as may be specified in the license and thereafter to construct, maintain and operate the pipeline and ancillary facilities. Also, the Oil and Gas Pipelines Regulations of 1995 provides detailed regulations for the design, construction and inspection of oil and effluent water disposal pipelines in addition to guidelines for the design and construction of oil transmission and distribution pipelines. It further provides for procedures for upgrading pipelines or changing of substances transmitted by the pipeline and for the discontinued use or EIA of Benisede Catchment Area FDP Phase 2 June, of 253

39 Chapter Three abandonment of the pipeline system. The Act makes it mandatory for a holder of a pipeline license to pay compensation to any person that suffers damage as a result of any ancillary installation. The Oil Pipeline Act and the Oil and Gas Pipeline Regulations of 1995 thus, do not require project proponents to conduct an EIA, but only to undertake a route survey. However, integrating the requirements of the Act and Regulations into the framework of the EIA is the most expedient approach to ensuring that all the provisions contained in these statutes are fully complied with Mineral Oils Safety Regulations 1963 (Amended 1997) These regulations provide that a licensee or lessee shall: Ensure that no pipeline is put into operation without the approval of the Director of Petroleum Resources; Make sure that the right of way of every pipeline is free of overgrowth and weeds in order to allow for easy access for conducting operational tests, other maintenance works and for prompt detection of leakages; Carry out cathodic protection potential survey on all buried pipelines at intervals of not more than 2 years to ensure that every section of the protected line attains a negative potential of not less than 850mV with respect to copper/copper sulphate reference electrode; Provide clear, comprehensive, safe and practical operational procedures and guidelines for the workforce; Develop and maintain contingency procedures and measures for the safety of personnel and equipment in an emergency; Maintain a documented system setting out the responsibilities of the competent persons involved in onshore and offshore operations, their mutual relations and lines of reporting and communications; Ensure that every personal protective equipment is judiciously used and maintained in serviceable condition at all times; Ensure that every pressure vessel and its fittings in use in an oilfield operation shall be regularly examined in accordance with the manufacturer s recommendations and good oilfield practices; Ensure that every pressure vessel equipment and associated piping used in oilfield installations meet the National Association of Corrosion Engineers (NACE) or other recognized equivalent standards for monitoring and EIA of Benisede Catchment Area FDP Phase 2 June, of 253

40 Chapter Three controlling corrosion, with respect to their design, construction, routine inspection, testing and maintenance; Ensure that every crane and hoist equipment to be used for work is operated by a trained person who shall always ensure that the equipment is inspected and maintained as recommended by their manufacturers; and Safely handle all diving operations and the activities of his diving contractors, to ensure that, as far as is reasonably practicable, the activities are carried out in accordance with all relevant local legislation codes, standards and other international safe diving practices National Environmental Protection (Effluent Limitations) Regulation (S.1.8) 1991 This regulation makes it mandatory for industries generating wastes to install antipollution and pollution abatement equipment on site. The regulation is specific to each category of waste generating facility with respect to limitations of solid and liquid discharges or gaseous emissions into the ecosystem. Appropriate penalties for contravention are also specified in the regulation National Environmental Protection Regulation (S.I.9) 1991 The National Environmental Protection (Pollution Abatement in Industries Producing Waste) Regulation of 1991 regulates the release of toxic substances, requirement for pollution monitoring unit, machinery for combating pollution and contingency plan by industries. It also provides that industries producing wastes should submit lists and details of chemicals used by such industries to FMENV as well as permissible limits of discharge into public drains. It details protection of workers, requirements for environmental audit and penalty for contravention National Environmental Protection (Management of Solid Hazardous Wastes Regulation (S.1.15) 1991 This regulation spells out the requirements for groundwater protection, surface impoundment, land treatment, waste piles, landfills, incinerators, etc. It also describes the hazardous chemical products and dangerous waste constituents. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

41 Chapter Three EIA Sectoral Guidelines of the Federal Ministry of Environment (FMENV) Federal Environmental Protection Agency (FEPA) now Federal Ministry of Environment (FMENV), was established by Act 58 of 1988 to monitor and prevent the pollution of the environment following the Koko toxic wastes dump incident. This empowered FEPA to prepare Environmental Guidelines and Standards as instruments for prevention of environmental pollution. This Act also gives specific powers to FEPA/FMENV to facilitate environmental assessment of projects. In addition, FEPA regulations S.1.8, S.1.9 and S.1.15 of 1991 provided guidelines and standards for the following: - Solid and Hazardous waste management - Effluent limitations - Pollution abatement in industries generating wastes. In September 1995, FEPA published EIA Sectoral guidelines for projects in the Oil and Gas industries in Nigeria. The guidelines are intended to assist in the proper and detailed execution of EIA Studies of the oil and gas projects in compliance with the EIA Act of The FMENV EIA Management process is shown in Fig PROPONENT FEASIBILITY STUDY OR PROJECT FMENV EIA SECRETARIAT INITIAL ENVIRONMENTAL EVALUATION MANDATORY PROJECTS OTHERS CLASSIFIED PROJECTS EXCLUDED PROJECTS PRELIMINARY ASSESSMENT SCREENING SCOPING NO EIA EIA of Benisede Catchment Area FDP Phase 2 June, of 253 REQUIR DRAFT EIA REPORT

42 Chapter Three Figure 1.2: FMENV EIA Management Procedure DPR s Requirements for EIA The Department of Petroleum Resources (DPR) was established by the Petroleum Act of 1969 and amended in section 191 of the NNPC Act of This Act empowers DPR to ensure that Petroleum Industry operators in Nigeria do not degrade the environment in the course of their operations. They also enforce the clean-up and restoration of Oil spills and impacted environment to acceptable levels, as well as control new projects that may adversely impact the environment. Thus the power of supervision over the entire operations of oil industries is vested on DPR. One of the principal regulations that mandates DPR to issue licenses/permits and establish guidelines, standards and procedures for environmental controls is Section EIA of Benisede Catchment Area FDP Phase 2 June, of 253

43 Chapter Three 8(1) b (iii) which empowers the Minister of Petroleum Resources to make regulations for the conservation of petroleum resources and prevention of pollution of water courses and atmosphere. Consequently, DPR requires by legislation, that holders of exploration, prospecting, refining, transportation and marketing licenses of petroleum resources take/adopt practical precautions and all steps practicable to prevent pollution, and cause as little damage as possible to the environment in their areas of operation. Therefore, the use of Environmental Impact Assessment as an environmental management tool is mandatory and is adopted by DPR as an additional enforcement strategy. Rules and regulations guiding the activities in the petroleum industry in Nigeria are specified in the Environmental Guidelines and Standards for the Petroleum Industry in Nigeria, EGASPIN 2002, issued by DPR. The DPR EIA Management process is shown in Fig SPONSOR Prepares and submits IEE to DPR DPR screens IEE with operator * 30 days REENING Project proceeds (with monitoring) EIA of Benisede Catchment Area FDP Phase 2 June, of 253 NO

44 Chapter Three Impact Significant? YES DPR constitutes Panel to scope full EIA Operator carries out EIA and submits EIA/EIS Draft to DPR DPR reviews draft and requests for final EIA/EIS to be developed * 21 days END Operator submits Final EIS to DPR * 7 days Figure 1.3: DPR Flowchart for the EIA Process Forestry Law CAP 51, 1994 The Forestry Act 1958 which was amended as the Forestry Law CAP 51, (1994) prohibits any act that may lead to the destruction of or cause injury to any forest produce, forest growth or forestry property in Nigeria. The law prescribes the administrative framework for the management, utilization and protection of forestry resources in Nigeria, which is applicable to the mangrove, and other forests of the Niger Delta Land Use Act of 1978 EIA of Benisede Catchment Area FDP Phase 2 June, of 253

45 Chapter Three The land-use Act of 1978 states that it is also in the public interest that the rights of all Nigerians to use and enjoy land in Nigeria in sufficient quality to enable them to provide for the sustenance of themselves and their families should be assured, protected and preserved Delta and Bayelsa States Ministries of Environment The States Ministries of Environment in Delta and Bayelsa States have the responsibility of environmental protection within their States. The applicable State regulations (e.g. DELSEPA Edict No. 5 of 1997) have been taken into cognizance as part of the proposed project. Some of the functions of the State Ministries of Environment include: (i) liaising with the Federal Ministry of Environment, FMENV (formerly FEPA) to achieve the National policy on Environment, (ii) co-operating with FMENV and other National Directorates/Agencies in the performance of environmental functions including environmental education / awareness to the citizenry, (iii) responsibility for monitoring waste management standards, (iv) responsibility for general environmental matters in the States, and (v) monitoring the implementation of EIAs and other environmental studies for all development projects in the States SPDC HSE Policy Shell Petroleum Development Company of Nigeria Ltd (SPDC) in her Health, Safety and Environment (HSE) Policy states that SPDC: (i) Has a systematic approach to HSE management designed to ensure compliance with the laws and to achieve continuous performance improvement, (ii) Sets targets for improvement and measures, appraises and reports performance, (iii) Requires contractors to manage HSE in line with this policy, EIA of Benisede Catchment Area FDP Phase 2 June, of 253

46 Chapter Three (iv) Requires joint venture under its operational control to apply this policy and use its influence to promote it in its other ventures, (v) Includes HSE performance in its appraisal of all staff and rewards accordingly. All operations/activities in the BCA FDP shall be carried out in accordance with the above-stated HSE policy objectives Other National and International legislation and Conventions Other National and international legislation and conventions relevant to the Benisede Catchment Area FDP are summarized in Appendix IV. 1.7 Structure of the Report This EIA report is presented in nine chapters. Chapter one is an introduction stating the background information about the project and the proponent and the legal/administrative framework for EIA in Nigeria. The second chapter discusses the project justification and presents the need / value and the envisaged sustainability of the project as well as the project development options considered. Chapter three contains a concise description of the proposed project activities including project scope of work, design philosophy, engineering/detailed design, project management and operations philosophies and the project execution schedule. The fourth chapter describes the existing biophysical and socio-economic baseline status of the project area as well as the health status of the residents. Chapter five presents consultation with identified stakeholders including host communities and regulators. The potential and associated impacts of the proposed BCA FDP project is presented in chapter six while chapter seven proffers mitigation and enhancement measures and alternatives for the identified adverse and beneficial impacts. Chapter eight describes the environmental management and community development plans that SPDC proposes to adopt during implementation of the proposed BCA FDP project. Chapter nine concludes the EIA report while presenting the key findings of the study. 1.8 Declaration EIA of Benisede Catchment Area FDP Phase 2 June, of 253

47 Chapter Three Shell Petroleum Development Company Ltd (SPDC) hereby declares that the BCA FDP project will be executed in compliance with the above stated legal and institutional frameworks. SPDC will therefore take responsibility to mitigate the identified impacts from the BCA FDP project. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

48 Chapter Three CHAPTER TWO 2.0 PROJECT JUSTIFICATION 2.1 General Benisede Catchment Area (BCA) comprises Benisede field and its satellite fields and prospects (i.e. Akono, Opomoyo, Osuopele and Orubou). Crude oil production commenced at Benisede Field in May 1976 with a cumulative production of 227 MMstb as at Peak rate was 47,850 bopd at 7% watercut in This declined to about 28 Mbopd at 46% watercut by mid Currently BCA produces about 34 Mbopd at 40% BSW. Only 48% of this production is from Benisede while Opomoyo, a small satellite field, contributes 40%. Latest estimate of Undeveloped Reserve was MMstb and 63 % of remaining reserves is considered yet undeveloped. 2.2 Project Objectives The objectives of the BCA FDP Project include; to generate a life-cycle field development plan for the Benisede Catchment Area (BCA), develop the remaining reserves in these fields (Benisede, Akono, Opomoyo, Orubou and Osuopele) and test neighbouring exploration prospects. This project also leverages on the Southern Swamp Associated Gas Gathering (SS- AGG) project building new oil and gas facility and providing the additional ullage required for further field development activities. In the short-term, the existing flowstation will be debottlenecked prior to its upgrade. Hence, this plan is aligned with SPDC s corporate sustainable development objectives through the gas-gathering project and the adoption of new EIA process. 2.3 Need for the BCA FDP Project Phase 2 SPDC s intention to further develop the BCA is based on the need to increase the hydrocarbon reserves of the country. The wells currently in the BCA field have long been in production. There is the need to upgrade the facilities so as to optimize as well as increase the hydrocarbon reserves of the BCA field. This will contribute to increase EIA of Benisede Catchment Area FDP Phase 2 June, of 253

49 Chapter Three in the total national hydrocarbon reserves and export earnings in a cost-effective and environmentally sound manner. 2.4 Benefits of the BCA FDP Project Phase 2 On completion, the benefits of the BCA FDP Project are numerous and cannot be over-emphasized. Some of the benefits of the BCA FDP Project will include: (i) Increase Nigerian Oil production and therefore provide a significant contribution to overall Nigerian oil level and hence boost the Nigerian economy. (ii) Improve the standard of living of Nigerians and therefore enhance socioeconomic development of Nigeria. (iii) Ensure gainful employment of Nigerians. (iv) The BCA FDP Project will reduce gas flaring and therefore contribute to environmental conservation. 2.5 Envisaged sustainability of the BCA FDP Project Phase 2 The key challenge of sustainable development for this FDP phase 2 project is to demonstrate its economic contribution, satisfy the growth for energy demand, whilst also safeguarding the environment and acting in a socially responsible manner. The sustainable development philosophy of minimizing land-take, cost and the impact on the environment has been adopted for this development project. The set goal is, meeting the needs of the present without compromising the ability of future generations to meet their own needs SOCIAL SUSTAINABILITY The social sustainability of the BCA FDP Phase 2 Project shall emanate from the extensive consultations, which have been held with host communities. These consultations, some of which have been sustained are expected to create a good working relationship between SPDC and the communities ENVIRONMENTAL SUSTAINABILITY The BCA FDP Phase 2 Project shall be environmentally sustainable because of the adoption of SPDC HSE policy and the improved EIA process for the project. Incorporating the findings and recommendations of this EIA and subsequent implementation of EIA of Benisede Catchment Area FDP Phase 2 June, of 253

50 Chapter Three the Environmental Management Plan for every phase of the BCA FDP project will ensure the required environmental sustainability ECONOMIC SUSTAINABILITY The BCA FDP Phase 2 Project shall be economically sustainable because of the huge hydrocarbon deposits (tabulated in Chapter 3.0) to be exploited in the BCA field. 2.6 Project Alternatives Three (3) possible integrated development alternatives/scenarios were identified: Scenario 1: No Action/Do nothing Scenario 2: Development activity with upgraded 90 Mbpd facility Scenario 3: Development activity with new 90 Mbpd facility Scenario 1: No Action/Do Nothing option This option involves the operation of the BCA field as is currently operated without any further development. This option was dismissed because it will not achieve the above-stated needs and benefits of the project. Scenario 2 (Brown Field): Development activity with upgraded 90 Mbpd facility This scenario considers the various ways of upgrading and increasing the capacity of the existing flowstation as previously discussed. Specific options considered include: a.) debottlenecking to 90Mpd, b.) Debottlenecking to 90 Mbpd and further capacity extension via the use of EPFs of various sizes and acquisition arrangement, c.) Debottlenecking to 90 Mbpd and installing a 30Mbpd third train. d.) Upgrading to 90 Mpd and installing gas gathering equipment through SFAGG. This scenario can deliver production acceleration by allowing new wells to be drilled earlier than the SFAGG (except for option d). They also allow flexibility for handling production upsides and a possibly earlier hook-up of exploration upsides. EPFs can be de-commissioned at periods of low peak and used elsewhere in the district. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

51 Chapter Three Besides the reasons previously stated, these scenarios are not viable for long term application given the absence of oil and gas integrated operations (except for option d) and the need for 24 hr manning. Hence, they are regarded as unrealistic for either being opposed to SPDC's new operating philosophy or the long-term sustainable development objective. For these reasons and the previous technical conclusions reached by the SFAGG team, no further evaluation of these scenarios was done. Scenario 3 (Green Field): Development activity with new 90 Mbpd facility Scenario 3 is completely aligned with the firm and committed SFAGG project to build a 90 Mbpd integrated oil and gas Mobile Production Facility. The decision to build a 90 Mbpd flowstation was reached by the SFAGG team following preliminary forecasts and economic runs comparing the 90 Mbpd. The strategy therefore, in the event of unexpected upsides in reserves or exploration gains, is to optimise ullage utilisation through water cut management. Generally, exploration gains will be deferred till ullage is created from natural production decline. The main risk presented to these scenarios is the impact of possible delays in the SS- AGG project and the resultant project value erosion. Scenario 3 is the preferred alternative given its economic advantages and environmental implications. This Green Field alternative gives opportunity for an integrated oil and gas facility, and thus incorporates SPDC s new operational philosophy of integrated oil and gas operations. The scenario is also in line with the Federal Government s flares down policy. Scenario 3 is therefore an environment friendly alternative. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

52 Chapter Three CHAPTER THREE 3.0 PROJECT DESCRIPTION 3.1 General This chapter presents the technical details of the proposed Benisede Catchment Area (BCA) Field Development Phase 2 Project. This includes the proposed BCA project location, project activities, design philosophy, wellhead design, drilling operations, mud programmes, etc and the overall project schedule. 3.2 Project Scope The scope of the proposed Benisede Catchment Area FDP project would cover the following principal activities: Collection and Transportation of materials; Land Acquisition (about Hectares); Drilling of 11 wells; Dredging; Laying about 50km of flowlines to the flowstation; Flowline and jacket construction; Clearing of the Right of Way; Purchase of the pipes; Coating of pipes; Welding and Laying of pipes; Radiography of welded joints; Excavation/Back filling; 3.3 Project Location The Benisede Field is located in the Swamp and Fresh-Water region of OMLs 35 and 46 (Fig. 3.0), about 65 km South-South-West of Warri (Map 1, Appendix I). It is situated between latitudes N and N and longitudes and E and is located within two local government areas; Burutu in Delta and Opurumor West Local Government Area in Bayelsa State. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

53 Chapter Three OTUMARA DELTA S. JONES CR. SAGHARA EGWA W. OKAN ESCRAVOS MEFA AFREMO ODIDI MEJI FORCADOS-YOKRI 45 EGWA E. BATAN AJUJU 42 UPOMANI 34 AGHIGHO 30 KOKRI RAPELE UGHELLI W AFIESERE OZORO ERIEMU WARRI RIVER OWEH UGHELLI E UTOROGU OSIOKA ORONI EVWRENI OWOPELE 46 ODON OKPOKONOU 31 ANGALALEI OGBOTOBO BENISEDE AGBAYA OPUKUSHI KANBO EJA EA SEIBOU NUN RIVER TUNU OML 35: 36 DIEBU CR. Benisede + Prospects PENNINGTON TEBIDABA Akono MIDDLETON Opomoyo N. APOI Orubou OKUBIE Fig 3.0: Benisede Catchment Area 3.4 The proposed project Overview The Benisede Catchment Area FDP Phase 2 project covers the lifecycle redevelopment plan of the Benisede Catchment Area (BCA) i.e. Benisede field and prospects, Akono, Opomoyo, Osuopele and Orubou fields (Fig. 3.1). A major drilling campaign will be carried out in Benisede Catchment Area. Eleven (11) new wells (8 in Benisede and 2 in Akono and 1 in Opomoyo) will be drilled and this will be made up of 9 horizontal wells and 2 conventional wells. Also in the plan is the laying of about 50 km of oil flowlines. In order to realise a gaslift gain (license period) of about 15.7 MMstb, a 20 km long 6" HP line will be laid from the Benisede flowstation to the Tunu-CPF when completed. Some 33 km of lift gas distribution lines will also be laid between the flowstation and wells requiring lift-gas in Benisede field. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

54 Chapter Three OML 46 OML 35 OSUOPELE SW FIELD OSUOPELE FIELD BENISEDE G PROSPECT BENISEDE FIELD BENISEDE D PROSPECT BENISEDE E PROSPECT AKONO FIELD BENISEDE C PROSPECT OPOMOYO FIELD Fig. 3.1: Benisede Prospects The BCA FDP is closely aligned to the SS-AGG project i.e. building new oil and gas processing and the additional crude processing ullage required for the new development. An upgrade of the existing 60Mbpd flowstation to a 90 Mbpd concrete badge mounted Flowstation is planned for commissioning in late Surface Locations Benisede Field The wells in Benisede field will be drilled from four surface locations consisting of two new locations and two location extensions. One well (S1S7T3C*) will be drilled as a stand-alone from a new location. This is because the appraisal objectives of the well require it to be drilled as a fault scooper and no existing well location is optimally placed to allow this. The second stand-alone well, Bens R6-H, (see Fig. 3.2) will be drilled from the extension of Benisede-11 location. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

55 Chapter Three Proposed Opom -H (With 5-/12 SL & ECP) Proposed BensR6-H (With 3-1/2 WWS) Proposed Bens -H (With 4-1/2 SL/WWS) Proposed Bens -H (With 4-1/2 & OHGP) refusal 24 refusal 24 refusal 13-3/8 9-5/8 9-5/8 9-5/8. 8-1/2 hole 6 hole 6 hole 6 hole /8 Shale layer, blank pipe Fig. 3.2: Completion Diagram for Benisede-H EIA of Benisede Catchment Area FDP Phase 2 June, of 253

56 Chapter Three The remaining two locations will be clusters. One of the cluster locations will be constructed from a new area and will have three wells (S7H9, S1H and T3H). The other cluster location will be an extension of Benisede-3 location and will have three wells (S7C, R7H, S2H2*). Thus the Benisede well construction operation will require the dredging of some 2.32 hectares (excluding access routes) of land Akono Field Two horizontal wells in Akono field will be drilled from a single surface location, which will be an extension of the existing Akono-1 location. This would require the dredging of about 1.0 hectare of land Opomoyo Field A single horizontal well in Opomoyo field will be drilled from a new surface location. Drilling from the existing Opomoyo-1 location was ruled out because it would require an extremely tortuous wellpath given the reservoir extension appraisal objectives of the well. The surface location would require the dredging of about 0.7 hectare of land. 3.6 Proposed Project Design Philosophy A nodal development philosophy has been applied in developing a full lifecycle FDP for the matured Benisede field and neighbouring fields. The strategy adopted leverages on the firm and committed Sustainable Development programme involving the building of gas gathering facilities, a new oil and gas processing facility and additional ullage capacity via the SS-AGG project. This FDP includes notional future development activities closely tied to additional ullage availability created by the SS-AGG project. Gas lift gains are to be reappraised towards the currently estimated ETT. An HP line is to be laid from the Tunu CPF if considered still viable and providing that compression ullage will be available as presently forecasted. EIA of Benisede Catchment Area Phase II Field Development Plan June, 2005 Page 57 of 253

57 Chapter Three Recently evaluated exploration prospects will be tested via the drilling of exploration wells. Hence, this FDP will be updated following the interpretation of these wells. A further FDP update will be required to generate Gas development activities. This will however depend on new commercial opportunities in the Gas market. 3.7 Engineering and Detailed Design Applicable Standards and Codes All Design and Engineering Practice (DEP) and SPDC standards and codes, applicable to various aspects of oil and gas projects such as mechanical, process, corrosion, pipeline, flowlines, and HSE shall be followed in the Benisede Catchment Area FDP project. In general, the project will be designed in accordance with: a) Relevant Nigerian Government Legislation; b) Project Specification and Concept; c) SPDC Specification and Standard; d) Design and Engineering Practices (DEPs), e) HSE Manuals; f) Procedure Guide for the Construction and Maintenance of Fixed Drilling platforms, Department of Petroleum Resources, Nigeria. g) Guidelines and Procedure of Oil and Gas Pipelines and their Ancillary Facilities, Department of Petroleum Resources, Nigeria. h) Procedure Guide for the Determination of the Quantity and Quality of Crude oil and Petroleum Products at Custody Transfer Points, Nigerian Ministry of Petroleum and Mineral Resources. i) API RP 2A-WSD: Recommended Practices for Planning, Designing and Construction Fixed Drilling Platforms Working Stress Design, 20 th edition; July, j) API Spec 2B Fabrication for Fabricated Structural Steel Pipe k) API RP 2G Recommended Practice for Production Facilities on Drilling Structure EIA of Benisede Catchment Area Phase II Field Development Plan June, 2005 Page 58 of 253

58 Chapter Three l) APE Spec 2H Specification for Carbon Manganese Steel Plate for Drilling Tubular Joints m) API 5L Specification for Line Pipe n) AWS D1.1 Structural Welding Code Steel o) API Standard 1104 Welding of Pipelines and Related Facilities p) API RP 1111 Design, Construction, Operation, and Maintenance of Drilling Hydrocarbon Pipelines q) ASME/ANSI B31.3 Chemical Plants and Petroleum Refinery Piping r) API RP 14C Recommended Practice for Design and Installation, and Testing of Basic Surface Safety Systems for Drilling Production Platforms s) API RP 14E Recommended Practice for Design and Installation of Drilling Production Platform Piping Systems t) ASME Boiler and Pressure Vessel Code u) Instrument Society of America (ISA) Recommended Practices v) API RP 500 Recommended Practice for Classification of Location for Electrical Installations at Petroleum Facilities Quality Assurance of Design SPDC will consider a quality assurance which defines certain basic parameters in the design of the overall project specifications of the various phases / aspects and components of the project. To ensure the full realization of the objectives of the project, SPDC has specified the following basic parameters in the design, which include: Simplicity and fit-for- purpose design to reduce cost; Minimization of redundancy in design and pre-investment for future expansion; Compliance with statutory requirements; Life expectancy; Production availability; Environment and safety; and Operability and maintainability EIA of Benisede Catchment Area Phase II Field Development Plan June, 2005 Page 59 of 253

59 Chapter Three At the implementation stage, SPDC will ensure that the above quality objectives are met by ensuring that: Design are executed via the use of verified and validated methods and design tools; Input parameters to the design are reviewed and checked for inconsistencies and errors; All design documents have a clear audit trial with respect to authorship, checking and approval signatories/authorities; and Specific quality practices and resources needed to meet the requirements of SPDC and all regulatory bodies are explicitly defined Well Trajectory Design The BCA well trajectories were designed using Anadrill's computer software (powerplan). The evaluation of the collision risks with existing and new well trajectories, using factor as the criterion, show that the collision risks is acceptable. A separation factor greater than 1.5 was maintained in the top hole and deeper intervals. To avoid crooked hole, the dogleg severity was limited to 1-2 /100ft in the top hole and less than 5 /100ft in the deeper hole section Wellhead Design Horizontal Wells Conventional or multi-bowl wellhead system can be used for the BCA FDP. For horizontal wells, this will consist of the following: 11" x 9-5/8" x 5K CHH to be installed on the 9-5/8" casing (complete with seal assembly, 11" x 7-1/16 x 5K DCB, running tools, side outlet valve). A solid block X-mas tree 7-1/16" x 5K (with preparation for control line, wing valve, choke box and SSV). This option can be used for all the horizontal wells in this development. However four of the horizontal wells can be slimmed down to 7" surface casing. For the slimmed down horizontal wells, the wellhead will consist of the following: EIA of Benisede Catchment Area Phase II Field Development Plan June, 2005 Page 60 of 253

60 Chapter Three 11" x 7" x 5K CHH to be installed on the 7" casing (complete with seal assembly, 11" x 7-1/16 x 5K DCB, running tools, side outlet valve). A solid block X-mas tree 5-1/16" x 5K (with preparation for control line, wing valve, choke box and SSV). This option can be used for Benisede R6H, R7H, R7H1 and S1H CONVENTION DEVIATED WELLS The conventional or multi-bowl wellhead system would be used for the conventional deviated wells (S1S7T3C* and S7C) and would consist of the following: 13-5/8" x 13-3/8" x 5K CHH to be installed on the 13-3/8" casing (complete with seal assembly, 13-3/8" x 11 x 5K DCB, running tools, side outlet valve. A solid block X-mas tree 11" x 5K (with preparation for 2 control lines, wing valves, choke boxes and SSVs) However the S7C conventional well would be slimmed down to: 11" x 7" x 5K CHH to be installed on the 7" casing (complete with seal assembly, 11" x 7-1/16 x 5K DCB, running tools, side outlet valve). A solid block X-mas tree 5-1/16" x 5K (with preparation for control line, wing valve, choke box and SSV) Casing Design There are two basic well designs for the planned wells in this development. The horizontal wells are designed for three hole sections viz.: 12-1/4" surface hole 8-1/2" build up section to landing in the reservoir 6" drain hole. The convention deviated wells will have two hole sections viz.: 16" surface hole 12-1/4" production hole for dual 3-1/2" production tubing. 12-1/4" surface hole 8-1/2" production hole for single 4-1/2" or 3-1/2" tubing. EIA of Benisede Catchment Area Phase II Field Development Plan June, 2005 Page 61 of 253

61 Chapter Three The casing schemes for the horizontal and conventional deviated wells will be respectively: 24" SP (driven) 9-5/8" (47ppf, N80) 7" liner (29ppf, N80) 4-1/2" slotted liner (13.3ppf, N80) or excluder screens. 24" SP (driven) 13-3/8" (68ppf, K55) 9-5/8" (47ppf, N80) for the 16" surface hole option. 24" SP (driven) 9-5/8" (47ppf, N80) 7" liner (29ppf, N80) for the 12-1/4" surface hole option Well Completion Design New Well Completion Design/Philosophy The completion designs are simple, proven and fit-for-purpose aimed at maximizing offtake rates without compromising ultimate recovery and well integrity. The new wells will be completed in a manner that will minimise well intervention but allow through tubing well intervention using wireline or coil tubing whenever required to maximise life cycle value of the wells. Attempt is made to avoid mechanical complexity associated with existing completions that make well intervention very challenging. Of the eleven new wells identified in this development, 2 are conventional and 9 are horizontal. Additionally, there is one existing well identified for workover. Conventional Wells Design Two new conventional wells: Bens-C* and Bens-C (Fig. 3.3) and 1 workover are planned in this development. Bens-C* will have cemented 9-5/8 production casing and completed as a two string dual (TSD) with 3-1/2 tubing strings in the S1.0 and S7.0 reservoirs. Bens-C will be com pleted as a monobore with 4-1/2 tubing on the S7.0 reservoir with an upside on the S2.0 reservoir. While the workover will be recompleted as single with a 3-/12 tubing. All the completion intervals need sand control and will be sand consolidated (SCON) for sand control except when the interval to be perforated exceeds 12 ft. This is due to higher productivity of SCON over gravel pack and accessibility through tubing re-entries for well repairs. The conceptual completion diagrams are shown ahead. EIA of Benisede Catchment Area Phase II Field Development Plan June, 2005 Page 62 of 253

62 Chapter Three PRO PO SE D C O M PLE T IO N FO R BE N ISE D E -C * (T SD ) PRO PO SE D C O M PLE T IO N FO R BE N ISE D E -C (M O N O BO RE ) /8 16 (SCON) 7 S C O N (SCON) 9-5/8 Fig. 3.3: Completion Diagram for Benisede C and C* Horizontal wells Five horizontal wells in Benisede will be completed as single string with 4-1/2 tubing while the remaining one will be completed with 31/2 tubing. One of the horizontal wells in Benisede, which will be completed on T3, will also be completed on S8 but placed behind sleeve. The production intervals of the horizontal wells will be lined and uncemented but will have sand control installed. The Sand control methods selected are WWS and OHGP/ESS. This is because of the relatively EIA of Benisede Catchment Area Phase II Field Development Plan June, 2005 Page 63 of 253

63 Chapter Three unconsolidated nature of the reservoirs, which require sand control installation to minimise sand production. The two horizontal wells in Akono would be completed as single string with 4-1/2 tubing. The sand control method will be WWS and SL respectively. Slotted liner will be used in the more consolidated sand (F3.0). The only horizontal well to be drilled and completed in Opomoyo on the F2.0 reservoir will be completed as a single string with 5-1/2 tubing due to the high rate expected (15000 b/d). Slotted liner can be deployed in the horizontal section since the sand is fairly consolidated. Plate 1: A well-head in the study area 3.8 Gas lift Requirement Currently, the reservoirs in BCA are producing naturally and can sustain flow to ca. 70% BSW. 3D-reservoir simulation using MoRes was used to quantify incremental recovery from gaslift. Incremental recoveries in wells that benefit from gaslift range EIA of Benisede Catchment Area Phase II Field Development Plan June, 2005 Page 64 of 253

64 Chapter Three from mstb. Many new wells in Benisede showed incremental recoveries due to gaslift. Hence all new wells planned in Benisede will be equipped with gaslift mandrels. Only a few existing completed strings showed incremental recoveries from gaslift since most wells are swept by encroaching aquifer due to production from updip wells (new wells which are crestally positioned inclusive). Eleven existing strings have gaslift mandrels installed. Hence, existing wells requiring gaslift will either be workedover to install gaslift mandrels or through tubing orifice check inserts will be used. Lift gas requirement for BCA is estimated at a maximum of 7 mmscf/d at optimum injection pressures of psig. The Akono and Opomoyo deep reservoirs have high GOR and will not require gaslift. 3.9 Production Commingling Production commingling opportunities are limited in the of Benisede development due to single targets in most wells planned. However, crude sampling for geochemical fingerprinting analysis is in progress. When completed, geochemical feasibility studies to determine if production allocation using GFA is possible in BCA and the number of end-members that can be combined. The results of these will be incorporated in the final plan of the two conventional wells and one horizontal well (Bens-T3H which is also completed on the S8 interval which is behind in the base case). Also, smart wells experiences acquired from the successful deployment of Smart Well technologies across the group and other companies will be monitored and learnings adopted for future development opportunities in Benisede Well Safety Enhancement Some wells in BCA were identified during the field review, which require safety enhancements. The table (Table 3.0) summarises the current status of these wells and plans in-place to address any outstanding safety issues. EIA of Benisede Catchment Area Phase II Field Development Plan June, 2005 Page 65 of 253

65 Chapter Three Table 3.0: The Current Status of BCA Wells and Safety Plans Wells Safety Issues Status Plans for Rectification Time and action party Bens 1L/S High Casing Head Pressure Presently safe. Bens 4S Bens 14 Bens 17L/S Com-unit will not operate on auto Com-unit will not operate on auto Inaccessible slots due to water hycinth. 17L Com-unit will not operate on auto Com-unit now operate on auto Com-unit now operate on auto Com-unit now operates on auto but access to slots still covered by water hycinths Bens-9L Leaking SCSSV C.I for Leaking SCSSV Bens 22L/S Bens 6L/S Bens 16L/S Inaccessible slots due to water hycinth.22l Comunit will not operate on auto Inaccessible slots due to water hycinth Inaccessible slots due to water hycinth Slots still in accessible and com-unit still not operating on auto Slots now accessible Slots now accessible Continue to monitor and bleed-off. If pressure builds up, Wire-line work required to locate and isolate the point of communication. If unsuccessful, well will be plugged and secured It is planned to fix the COM units to operate on auto or change them out. It is planned to fix the COM units to operate on auto or change them out. Maintain access to slots by regularly clearing the weeds. It is planned to fix the COM units to operate on auto or change them out A wireline barge to be deployed to changeout leaking SCSSV and restore well back to production in Q Maintain access to slots by regularly clearing the weeds. It is planned to fix the COM units to operate on auto or change them out Maintain access to slots by regularly clearing the weeds Maintain access to slots by regularly clearing the weeds Q PCW:PTC/W EL Closed out Closed out Monthly PCW/STS2 Q PCW:PTC/W EL Q PCW/STS2 Closed out Closed out Drilling Rig Selection The major drivers for rig selection are SPDC's drive to reduce impact on the environment, increase production, increase operational efficiency and reduce well EIA of Benisede Catchment Area Phase II Field Development Plan June, 2005 Page 66 of 253

66 Chapter Three capex. A cluster-drilling rig is expected to meet most of these requirements and is therefore the preferred rig type. The other key factors in the rig selection are the rig rate and operational efficiency (contractor experience, competence of staff and equipment up time). Although the fields in BCA are not known for severe hole problems, there are few deviated wells (six in Benisede field; max 40 in Benisede-8) and no horizontal wells. In view of the more complex nature of the new wells and the need for well construction efficiency the rig should be equipped with a top drive. The minimum specifications/requirements for the swamp drilling rig are as follows: MODU Type Operating Envelope Moon Pool Area Water Depth Drilling Depth Mast Draw Works TDS BOPs Mud pumps Mud Tanks Bulking Capacity Deck load Environmental Aspects Security Swamp Barge Cluster Drilling (minimum 6 wells) 16 ft x 8 ft >40 ft x 20 ft ft 15,000ft (measured depths) 1,200, klbs (9-5/8" 47# csg to 12000ft) TDS-4S or TDS-3H ft-lbs. (torque rating) 13-5/8" x 5000 psi minimum Up to 1200 gpm; Up to 5000 psi surface pressure Capable of handling POBM and WBM bbls storage 9000 cu. Ft short tons Dry location concept Ability to keep out unwanted visitors 3.12 Mud Systems Water-based mud and Pseudo-oil based mud will used in different hole sections. The mud weights for each hole section will be based on drilling experience in the field as well as STABOR simulations (especially for the build-up sections of horizontal wells) Surface Hole (16" for Conventional or 12-1/4" for horizontal) Water based mud (WBM) will be used drill surface hole sections of horizontal or conventional wells. Typically Bentonite/CMC spud mud will be used to commence EIA of Benisede Catchment Area Phase II Field Development Plan June, 2005 Page 67 of 253

67 Chapter Three drilling and converted to KCl/Polymer below the base continental (typically below 4000 ft tvd) where shale layers will be encountered Build Section (8-1/2" for horizontal) The build up section of horizontal wells to landing point will be drilled with pseudooil based mud (POBM) to advantage of the performance benefits of POBM in terms of borehole stability and lubricity. However, drilling with POBM present some challenges with respect to the management of drill cuttings in accordance with regulatory (DPR/FEPA) requirements Production hole Section (12-1/4" for Conventional wells) The production hole section (i.e. below surface casing shoe) of conventional deviated wells will also be drilled with pseudo-oil based mud (POBM) for similar reasons and challenges as stated for the 8-1/2" build up section of horizontal wells. The POBM mud cake clean up is not expected to present production problems since the production intervals will be perforated after casing and cementing Drain Hole (6") The 6" drain hole sections of horizontal wells will be drilled with water based mud. The mud will be calcium carbonate weighted KCl/Polymer mud. This is preferred to POBM or barytes weighted WBM because of concerns about mud cake clean up after the well is brought into production. Calcium carbonate mud cake can be cleaned up easily using a specially formulated weak acid recipe. However the ongoing cited could result in the used of POBM for this hole section Cementation Class A cement slurry or lightweight (gradient: psi/ft) Class G cement slurry can be used to cement surface casings. The lightweight slurries will have heavy tail slurry to ensure better casing shoe integrity. To avoid losses the surface casing will not be cemented to surface. The top of cement for surface casings is expected at ±3000 ftah. The surface casing will be re-cemented from surface to below the stovepipe using a metal petal basket. Production casings and liners will be cemented with heavy (gradient: psi/ft) class G cement slurry. The top of cement in production casing for conventional EIA of Benisede Catchment Area Phase II Field Development Plan June, 2005 Page 68 of 253

68 Chapter Three deviated wells would be at least 500 ftah above top shallowest hydrocarbon bearing interval in line with SPDC and regulatory requirements. The 7" liners shall be run with liner hangers with integral packers to avoid the need to drill cement on top of liner after cementation. All steps will be taken to ensure good primary to avoid costly remedial squeezes, which may not achieve the required objectives. For hole section with gas bearing sand intervals gasblok additives will be added to the slurry Waste Management Waste management during the BCA FDP Phase II project shall be in line with FMENV regulations while striving to reduce, re-use, or re-cycle. All wastes that cannot be re-used or re-cycled will be properly disposed. Waste water-based mud slurry and brine will be re-injected into the CRI well at Opukushi-19. Water based mud cuttings and psuedo-oil based mud cuttings will be processed with solids control equipment to reduce mud on cuttings. The cuttings will then be treated at the TDU at Forcados Terminal after which it will be disposed at designated dump sites (Kokori). Sanitary wastes will be handled by biological treatment on the rig while domestic waste will be transported to dedicated SPDC handling facility in Jeddo. Paper waste shall be recycled at the waste recycling depot in Ogunu. Spent lube oil and diesel spills will be collected in dedicated storage tanks and taken to the TDU for treatment. Other industrial wastes such as plastics, metals, rubber and wood will be segregated on site and collected in designated baskets. The wastebaskets will be transported to Ogunu for recycling. Detailed waste management methods are presented in chapter eight of this report Project Schedule The BCA FDP project shall be placed on the long-term drilling sequence and shall be executed within the business planning cycle inputs (i.e. submission of project forecasts and economics for corporate ranking). EIA of Benisede Catchment Area Phase II Field Development Plan June, 2005 Page 69 of 253

69 Chapter Three The drilling was originally scheduled to start in 2005 but is now delayed because of alignment required with the Southern Swamp Integrated Oil and Gas Project (SSIOGP) to harness the expected Associated Gas (AG) to the Liquefied Natural Gas (LNG) train in line with the flares out date of Figure 3.4 shows the project schedule for the proposed project. EIA of Benisede Catchment Area Phase II Field Development Plan June, 2005 Page 70 of 253

70 Chapter Three FIGURE 3.4: BENISEDE PHASE 2 PROJECT PLAN REVIEW IN LING WITH SSIOGP BENISEDE PHASE 2 CAMPAIGN DRILLING PHASE LAY FLOWLINES AGG START UP EIA of Benisede Catchment Area Phase II Field Development Plan June, 2005 Page 71 of 253

71 3.16 Production Operations Plan Production Facilities Production facilities in the Benisede Catchment Area comprise wellheads, flowlines ands a flowstation. Current well locations and wellhead facilities Current data on Benisede field completion is presented in Table 3.1. BCA fields are situated in a swampy terrain. Hence, all the existing wells have conductor supported swamp wellhead platforms located in dredged slots. All the BCA reservoirs have produced to date on natural drive although 11 strings are equipped with gaslift mandrels. EIA of Benisede Catchment Area FDP June, of 253

72 Table 3.1: Current Benisede Field Completion Data Table Benisede Field Completions Data Well Size of Flowline (inch) Year Flowline Installed Type of Well String GLM? Data Completed Flowline Length (m) 1 Vertical 001L Aug S Aug V Mar Vertical 002T Jul Vertical 003T Jul-76 4 Vertical 004L Dec S Dec V Dec-76 5 Vertical 005T Apr Vertical 006L Oct S Oct Deviated 009L YES Jan S YES Jan V Jan Vertical 010L YES May S YES May Vertical 011L Apr S Apr Vertical 013T Require G/L Deviated 014L Sep S Sep Vertical 015L Sep S Sep Deviated 016L Oct S Oct Vertical 017L Require G/L Feb S Feb Vertical 018L Require G/L Mar S Mar Vertical 019L YES Oct S YES Oct Vertical 020T YES Nov Vertical 021L YES Dec S YES Dec Deviated 022L YES Dec S YES Dec AKONO FIELD 1 Vertical 001L(C.I) May V(L) May S May OPOMOYO FIELD 1 Vertical 001L Jun V Jul-96 The Flowstation 001S Aug EIA of Benisede Catchment Area FDP June, of 253

73 The existing Benisede flowstation (Plate 2), commissioned in 1976, is a standard SPDC swamp piled flowstation with a nominal capacity of 60MBD. The station consists of two process trains of 30MBD capacity each, all on a single deck. Each train consisting of a high-pressure (HP) separator, low-pressure (LP) separator and Surge vessel operates in series. The station is equipped with a Test separator used for statutory well testing. Plate 2: Benisede Flowstation The current flowstation also has eight (8) inlet manifold skids with forty-eight (48) ligaments. Out of these, 11 are presently not in use. Each of the manifold skids contains six 3 ligaments and four (4) headers (Test, HP1, HP2 and LP), with pipings rated at ANSI 600#. The flowstation is equipped with a single test separator. The Directorate of Petroleum Resources (DPR) requires that each well be tested at least once a month. Well tests are also required for well performance monitoring and hydrocarbon accounting. Crude oil from the wells is directed to either test, HP or LP inlet manifold headers depending on the flow line pressure. From the inlet manifold individual headers run to each separator via automatic shut down valves. The LP separators share a common EIA of Benisede Catchment Area FDP June, of 253

74 header and isolation valves are provided between the two LP separators. Each of the HP separators has a separate inlet header. There are inter-connecting pipings between the trains for operational flexibility. All the production separators are two phase (gas-liquid) separation vessels operating in series. The HP crude after degassing in the HP separator, flow to the LP separator and from there to the surge vessel. The low-pressure wells flow directly to the LP separator and from there to the surge vessel. The HP, LP and surge vessels pressure are set at 150, 50 and 6 psig respectively to optimise liquid production and minimise liquid carry over to the flare. Crude oil is evacuated from the flowstation by centrifugal pumps installed downstream of the surge vessels into the delivery line via the metering skid. The flowstation is equipped with 5 sulzer pumps each with a nominal capacity of 20MBD. Crude is exported through a new 8 line directly to Trans Ramos pipeline, and the old 12 x 21.2km delivery line via Isampou manifold. Only a small quantity of produced gas is utilised as instrument gas and fuel gas for gas engines and generator sets. The rest are routed through the appropriate HP and LP gas headers to the 16 flare gas header en-route the flare. The shortcomings of the present facility are: Requirement of 24-hour resident manning Pneumatic instrumentation with attendant venting and relief. Intensive maintenance Non-dependent Community Assistance Facility Constraints, e.g. increasing pump pressure due to high back-pressure in export line Community problems Non-segregated drains Manual operations Logistics problem Age of the facility (above 25 years) EIA of Benisede Catchment Area FDP June, of 253

75 Utilities Power/HP Fuel/Instrument Gas Systems Utility gas required for flowstation instruments, power and fuel, is tapped upstream of the HP separator at the Back Pressure Control Valve (BPCV) and routed to the Instrument and Fuel gas scrubber. The gas is subsequently directed via pressure regulators into instrument gas filters (in parallel), the fuel gas scrubber (for pump drivers) and power gas scrubber (for electricity generators) before reaching the various users. Utility Air A skid mounted diesel-engine driven air compressor unit (standard Ingersoll Rand T 30 Model 7100) supplies the start air required for kicking off all gas engines in the plant. The air receiver is off-skid mounted. Electric Power Supply Systems A gas-engine driven generator (Cat 3306) provides electric power requirement in the flowstation. This is rated for continuous duty at 281KVA, 415/240 volts at a nominal speed of 1500 rpm. The rating is based on meeting the minimum flowstation requirements. The electric power supply system comprises other utility items such as lubricating system, instrumentation and control, mode selector switch, protection devices, starting system and fuel gas system. The gas engine driven generator is complimented by a diesel-engine driven generator (CAT D3406), rated for continuous duty at 225 KVA 415/240 volts and a nominal speed of 1500 rpm. This generator is operated as standby machine when the gasengine electric generator is out of service or during extended shutdown. It is designed to be manually started and take over power generation each time the primary generator is out of service. Flare System Currently, the remainder of utilised process gas is sent to the flare system. This consists of two 16" diameter flare headers teeing off from a single bulk 16 main header. The flare comprises two 30 horizontal flare barrels complete with a flare tip EIA of Benisede Catchment Area FDP June, of 253

76 and flare pilots. A Flare Liquid Knockout Pot for removing liquids from the flared gas is installed along the flare line to minimise liquid carryover to the flare. The maximum instantaneous flaring rate during emergency is the blowdown rate. The normal continuous rate is 30mmscfd and the minimum rate 0.2 MMscf/d or less during periods of reduced oil production. Metering Facility Crude oil metering system The existing crude oil metering system consists of four parallel connected 6" positive G6-S7 displacement meters with mechanical counters, installed on the 8 discharge line. There is provision for a fifth meter. Each train has an installed capacity of 34,000 bpd and is provided with inlet and outlet block valves to permit their removal for servicing. Each is also provided with a basket strainer. Other process control facilities provided to the metering skid include a dial thermometer, a pressure transmitter connected to the CAO System, a pressure and temperature recorder and a high-pressure trip device connected to the CAO System. Test separator The test separator is equipped with two Postive Velocity (Rotron) meters and a Daniel Senior Orifice meter on the liquid and gas outlets respectively. The latter meter is provided with flow and pressure recorders. Additional meters have been installed on all the production separators' gas outlet lines to monitor the gas produced / flared. The test separator is used for periodic testing of individual wells in line with statutory requirements. Its set pressure depends on the pressure regime of the well being tested. When a HP well is being tested, the outlet liquid flows to the LP separator for further degassing and from there to the surge vessel. When a LP well is being tested, the outlet liquid flows directly to the surge vessel. The Future Facility EIA of Benisede Catchment Area FDP June, of 253

77 It is desirable to have a station adequately sized for future new oil and one that is better aligned with new corporate operating philosophy. Hence, this station must be designed for a fail safe, unmanned operation with auto restart. CAO/Restart monitoring must be installed on facility and logistics centre. A station attendant will however be required for a 24 hours monitoring of the facility and to provide minimal intervention on ad hoc basis particularly for Emergency Response duty like spill control. It will however be required to provide some training to station attendants to achieve a level of production competence needed for this task. New Oil and Gas Facility The following is a description of the green field facility upgrade option selected for this project: Process Description A new Integrated Flowstation (IFS) will be built. It is designed to be as much as possible similar to the existing flowstation such that similar equipment is utilised to optimise sparing and ultimately reduce cost of training of operators. The old plant will be decommissioned and abandoned as soon as the IFS is hooked-up. The IFS will be barge based and situated adjacent to the existing Benisede flowstation. The main facilities will include two 45 Mbpd production trains, gas gathering and booster compression and sand monitoring/removal appliances, besides the required utility and support systems for unmanned operation. Electric power will be imported from the Central Power Generation plant at the Tunu CPF via underwater cables. Each production train will consist of a LP Separator, HP Separator and a Surge Vessel (SV). The LP and SV gas will be gathered and boosted to HP pressure to join the HP gas for export to Tunu CPF for further compression and processing. The operating conditions of the IFS are tabulated below: EIA of Benisede Catchment Area FDP June, of 253

78 Pressure [bar(g)] Temperature [ C] HP LP SV HP LP SV Crude oil is evacuated by 4 variable speed electric driven pumps in a 4 x 33% configuration. Each pump has a capacity of 30 Mbpd and rated discharge pressure of about 90 barg. Inlet Manifold The inlet manifold skids will provide some 72 ligaments with pipings rated at ANSI 1500# for the tie-in of the existing and new incoming flowlines to the IFS. Future Facility Utilities Power/HP Fuel/Instrument Gas Systems Gas from the LP separator is used as fuel gas. The fuel gas system configuration consists of a fuel gas KO (knock out) drum and fuel gas filters (2 x 100%). The fuel gas system distributes fuel gas to the Flare header (purge) and Flare pilots. Other users where blanket gas is required include: open drains tank, sand collection tank and chemical storage tanks Utility Air The instrument air system consists of an instrument air receiver and instrument air packages (an n+1 sparing arrangement is assumed). The package includes compressors, filters and dryers. Instrument air is supplied to the instrument air distribution system and, under pressure control, to the utility air system. Electric Power Supply Systems Electric power will be supplied to the IFS from Tunu CPF through underground cable. An emergency diesel engine driven generator will be provided to supply essential services when main power is unavailable. Emergency power supply will be specified during the conceptual engineering phase. Flare System EIA of Benisede Catchment Area FDP June, of 253

79 A flare system is included for the following service requirements: Emergency blowdown Maintenance de-pressurisation Pressure relief operations Long term operational flaring in the event of compression or gas export system outage Operational drainage ( low pressure liquids from the booster compressor suction scrubber) The flare system consists of flare collection headers routed to the flare knock-out vessel. Liquid from the flare KO vessel is pumped to the process. Vapour is routed to a vertical flare located off-site. A flare ignition panel and pilot burners (flame front propagator type with propane bottle gas supply) are included Campaign Operations and Maintenance Operations and Maintenance will be carried out on campaign basis. Production and maintenance team for Southern Swamp - 2 District will be based in Tunu Logistics base on a week on week off basis where remote monitoring of the Benisede facility among others will be conducted. Visits will be made to the stations for routine operations activities and preventive maintenance although the flow-station attendants shall be present in the facility 24hrs/day on 12hrs/day shift. Boat requirement for well-head operations and other necessary work will be integrated into the district requirement and co-ordinated centrally at the logistics base. Ad hoc manning accommodation for operation and maintenance purpose and other logistics requirement for manning gas gathering/lift facility will be provided on the MPF. Campaign Maintenance A team of maintenance personnel comprising all required skill will carryout routine and planned maintenance on the equipment in the facility. The team, EIA of Benisede Catchment Area FDP June, of 253

80 which will be based in the Field Logistics base in Tunu, will take care of the facility along with others in the district. Maintenance Objectives/Strategy The following are the maintenance objectives for BCA facilities: To ensure the safety and security of people, environment and equipment in accordance with statutory and company requirements throughout the lifetime of the facilities. To maintain technical integrity, with high reliability to guarantee uninterrupted crude oil production. To allow for flexibility and expandability in design of facilities for further integration of other SPDC facilities into the utility support services of the station. To minimise operating costs of facilities. To achieve these objectives the maintenance strategies as laid down in the asset maintenance policies and guidelines will be adopted as appropriate. Manning Production operation will be carried out by an integrated team designated for the entire district and shall meet the demands required to maintain the integrity of the station and optimise production. The production staff (per rota) shall be of the following levels: 1 Team Leader/Area Production Supervisor 1 Instrument/Electrical/Mechanical Supervisor 2 Operator/Foreman 4 Fitters (Mechanical, Electrical and Instrument) with more emphasis on Instrument/Electrical depending on Team Leader/Area Supervisor s discipline. The station attendants shall be on 12 hr shifts (2 per shift) while others will be on duty from 0700 hrs hrs daily whenever the need arises. They shall however be available for emergencies subject to management approval. EIA of Benisede Catchment Area FDP June, of 253

81 The Tunu logistics centre will have enough accommodation to accommodate all staff with provision of overnight facility for extra staff per shift. In addition accommodation will be provided at the flowstation site for one Production foreman who may be on site on ad hoc basis and 2 station attendants. Security patrols will be installed at the flowstation area. No night sailing rules (Reference: No Night Sailing Policy of August 1998) shall be strictly adhered to. Process Monitoring, Control & CAO The process control and shut down systems shall be fail safe with minimum operator intervention. Consideration should be given to upgrading the currently designed Flowstation as part of development modification, in line with the current company safety standards and specifications. Major equipment will be started locally (exception being electric driven equipment with adequate control) and sufficient information/interlocks shall be provided to a safe start up. Emergency shutdown system (ESD) checks shall be carried out at sixmonthly interval in line with regulation (Mineral Oil and Safety Regulations of 1997) to ensure integrity while wellhead checks shall continue at the stipulated intervals. The current Computer Assisted Operations philosophy requires that data points be presented as electronic signals as a building block for the CAO system implementation strategy. Where available, systems shall be based on the open-system infrastructure. Equipment Selection New flowlines shall be designed to withstand maximum closed-in tubing head pressure (CITHP) attainable in the network, according to the standard flow line design philosophy. Old lines shall be replaced to the same standard when due, i.e. in accordance with corporate guideline for 14-years swamp flow-line replacement. The flow station shall be designed for at least 95% availability. A sparing philosophy of N+1 shall be applied to key equipment e.g. pumps, generators, air compressors etc. where N is the peak number required for normal effective operation. Crude evacuation pumps shall be electric motor driven centrifugal capable of delivering high EIA of Benisede Catchment Area FDP June, of 253

82 volume. Variation from this philosophy shall be subject to management s approval based on positive results of overall system effectiveness and equipment vulnerability studies. Where possible, equipment and instruments shall be common with that used elsewhere in SPDC. Well Testing and Metering. In line with statutory requirements (Mineral Oils and Safety Regulations, 1997) well testing shall be carried out for each well at least once a month to establish gross production rate and GOR. On the gross liquid outlet of the test separators, meters shall be installed that can measure with a design accuracy of at least +2%. The metering system shall operate with a turn down from 10,000 to 100 b/d, usually this is achieved through a single 3 Coriolis meter. A higher capacity meter shall be installed if high gross wells are brought on stream. The gas lines of separators shall be designed to ISO 5167 with the intention of achieving an accuracy of at least + 2%. Coriolis meter will be used for export metering. The integrity of the meters shall be determined by frequent maintenance. The meters shall continue to be regularly proved by differential method. The station water cut shall be determined from BS&W measurement reading from the Coriolis export meter and compared with computed results obtained from individual well s test figures. Gas meter shall be installed on each of the gas lines and the flare for accurate measurement of gas produced and flared. Isolation Draining and Cleaning All non-routine operational jobs in the station shall be covered by the Permit-To- Work system and Job Hazard Analyses carried out to ensure safety of People, Equipment and Environment. Isolation shall be such that an item of equipment or a system can be separated from and not be affected by a live plant. Thus allowing work to be carried out safely and efficiently on an item without danger from other adjacent live equipment. EIA of Benisede Catchment Area FDP June, of 253

83 Drains shall be designed to allow for segregation of hazardous and non hazardous liquids as follows: Process drains shall be collected through closed drain headers into vessels to be re-injected into the process, stream by electric-driven pumps. Continuously Oil Contaminated drain like bleeders, sample points which shall be collected through closed drain headers into vessels to be re-injected into the process stream. Accidentally Oil Contaminated drains like wash water, skid drain that shall be collected into drip pans into the saver pit and the mixture of oil and water is to be re-injected into the process stream. Storm water drain (from roof tops etc) shall be routed directly to the river or tanks for routine washing purposes. Thus the process area shall be roofed. Good Housekeeping shall be encouraged at all times in the facility with adequate provision of adequately labelled waste bins and waste segregation in line with SSA Waste management principle and ISO14001 standards. Safeguarding Systems Fire detection systems are provided in high-risk areas (transfer pumps, generators etc.) in line with company policy. Fire hydrants and portable fire extinguishers will be placed at strategic location to fight small incipient fires. In the event of an uncontrollable fire outbreak, personnel will be evacuated according to laid down evacuation procedures. The two levels of shut down systems (ESD and OSD) shall be maintained in the facility. All trip devices have individual indications and alarms at the DCS. The ESD system will be fail safe. With electronic instrumentation, full function tests of ESD systems shall be carried out at least twice a year. EIA of Benisede Catchment Area FDP June, of 253

84 All facility and field monitoring/testing equipment shall be inspected regularly in accordance with SPDC maintenance procedure guide and mineral oil safety regulations (Mineral Oil and Safety Regulations of 1997). Individual maintenance bypass shall be installed for each instrument to facilitate on-line testing. Instrumentation Instrumentation will be designed for remote status monitoring, calibration and configuration. Reliability of the instruments will allow for on failure maintenance. Application of AIMS All maintenance activities will be based on SAP-compliant company approved Asset Integrity Management System (AIMS). The technical integrity of assets will be maintained using a computerised maintenance management system (i.e. IMMPOWER or SAP R/3 when available), again to be applied in compliance with SPDC maintenance policies. Accessibility will be provided to the system via the divisional IT server Network at all key locations. Activity Planning An Operations Reference Plan shall be developed for the project and shall form the framework for planning for the facility. An annual review of the 5 years Integrated Operations Activity plan (IOP document) will be conducted, based on the latest company business plan for the program period. Firm projects with associated budget commitment will be logged in a 2-year integrated activity plan. The execution plan shall be discussed monthly, during the 90 days integrated operations meeting where the actual date for the execution of the projects are determined based on production optimization and shutdown requirements. 14 days Activity scheduling shall be used to capture activities firmed up for execution. Spare Parts For new equipment, operational and insurance spares shall be identified by the production function in line with vendor recommendations and SPDC requirements. Two years operating spares and special maintenance tools will be provided as part of the initial equipment purchase and should be available on site prior to hand-over. Spare Parts Interchange-ability Records (SPIRs) shall be provided by the vendors, EIA of Benisede Catchment Area FDP June, of 253

85 which will be reviewed by the Area team before stocking of the spares. The use of electronics SPIR will be actively pursued. Equipment Handling & Site Access Requirements Facilities and special equipment shall be designed for the handling of equipment and material where required. Good access shall be provided for on-site maintenance activities without need to interfere with non-related components. Design of the facility layout shall incorporate ease of access considerations for overhead cranes, jigs and personnel. All duplicated and auxiliary systems shall be segregated so that one can be maintained while the other is in operation. Workshop Facilities The divisional workshop shall continue to provide assistance in the following areas: Testing and calibration of Mechanical, Electrical and Instrument components Major overhaul of rotating equipment Machining and fabrication of simple parts In addition, a workshop shall be provided in the Tunu Field Logistics Base (FLB) which shall serve the purpose of second line maintenance for BCA besides other facilities in the district. It shall take care of all electrical, mechanical and instrument repairs requiring more than routine and planned maintenance Materials and Logistics Central warehousing All supplies of lubricants, chemical fuel and catering requirements shall be regular in accordance with current supply strategy. A standard jetty with loading and off-loading davit crane installed is already available for this purpose. To prevent shortage and optimize storage, a central warehouse will be provided in Tunu FLB which will serve as the hub for Benisede and other facilities in the district. Materials will be ordered, stored and administered centrally for the district from the warehouse. EIA of Benisede Catchment Area FDP June, of 253

86 Transportation Transportation to and from the facility shall be by air or boat. Transport and logistics shall be administered centrally at the FLB for optimisation purpose. For smooth and effective operations, the following shall be provided: Operational boat Police patrol boat Chopper flights Item No/Frequency 4 trips per week 1 per day 4 return flights (minimum) per week A helipad shall also be provided on the flow station barge and constructed to SPDC standard specifications. In the event of an emergency, transport shall be requested through the laid down procedures Production Operations CASHES Aspects Community Affairs in Production Operations All matters concerning community affairs around the facility shall first be directed to the Production Supervisor who will inform the appropriate sections (Community affairs). In the event of violent community disturbances which impact on production, station shall be made safe and staff shall return to base until the problem is resolved. Electricity shall be provided to the neighbouring communities and tied to the facility to ensure interdependency. Safety in Production Operations Where hazards cannot be eliminated, they shall be identified, assessed, registered and controlled, should loss of control occur, all existing recovery systems and procedures shall be put in place to reduce the effect of such incident. Hazard registers shall be reviewed annually and updated as required. Portable fire extinguishers and fire hydrants shall be strategically located for fire fighting and checked at set intervals by the fire department. Escape routes shall be clearly marked to the mustering point. Hazardous areas shall be well defined. EIA of Benisede Catchment Area FDP June, of 253

87 All safety measures presently in place will be maintained as follows: Job hazards analysis and toolbox meetings before embarking on a job. Wearing of PPE for designated areas. Prohibition of alcohol in the facility. Prohibition of night sailing. Prohibition of use of petrol engine and open roof speed boats for operations. Regular emergency drills. Prohibition of smoking in designated areas. Restriction of uncertified swimmers from the facility. Health Aspects of Production Operations Local, SPDC and Group s Seven Minimum Health Standards shall be adhered to at all time. Caterers shall be checked 6-monthly by MDW to check food handling hygienic standards. A well-equipped first aid box shall be available in the facility for first aid purposes only. Severe or more serious cases will be addressed according to MEDEVAC & MEDRESCUE procedures. Environment Aspects of Production Operations In compliance with Group Minimum Environmental Expectations and ISO 14001, any excess gas shall be flared and not vented into the atmosphere. Hazardous and non-hazardous drains shall be segregated. The contents of the saver pit shall be reinjected into the surge vessel while all contingency plans for pollution control shall be maintained. Where discharges are unavoidable, they shall be closely monitored and minimised. All generated waste shall be disposed of according to SPDC waste management procedures and EIA standards. Records of such shall be kept according to ISO14001 standard. Measurement of the flare quality for gaseous effluent and sampling for aqueous effluent shall be conducted in line with legislation requirement. Security Aspects of Production Operations There shall be regular patrols of wellheads and flow lines at day times. The security patrol boat shall be centrally located in Tunu FLB and shall conduct regular patrol and EIA of Benisede Catchment Area FDP June, of 253

88 shall respond to distress calls. Future design should incorporate modification to restrict unauthorised access (security fence/cage) Well Decommissioning/Abandonment All wells that have no economic value will be decommissioned and abandoned in line with SPDC Well Abandonment Policy. Four wells in Benisede field (Benisede-2, -8, - 9, -12) have reached the end of their productive lives are due for abandonment. One of them (Benisede-8) is being considered for re-completion as a cutting re-injection well. Given the advantage of campaign abandonment, the decommissioning/abandonment of the wells that have currently reached their productive live will not be carried out during this round of development. They will be shut-it and suspended till such a time when sufficient candidates will be available to allow campaign abandonment. However, the cost for well decommissioning/abandonment is usually captured as part of SPDC economics. EIA of Benisede Catchment Area FDP June, of 253

89 CHAPTER FOUR 4.0 DESCRIPTION OF ENVIRONMENT 4.1 General This chapter presents the environmental baseline description of the proposed Benisede Catchment Area (BCA) Field Development Project area. The baseline was produced using the two-season Benisede Catchment Area FDP Baseline Study Report and a single season ground-truthing in October The details of the methodologies adopted for data acquisition for each of the environmental components and the Impact indicators are described in Appendix II while the sampling location map (Map 2) is provided in Appendix Description of Existing Environment Relief/Topography The BCA field is covered with freshwater swamp with galloping terrain composed of alternating ridges and gullies. The topography of the area is low lying with some depression. Raffia palm, oil palm, ferns and grasses dominate the field. The area is drained by two main water bodies (Bomadi and Brass Creeks) Climate and Meteorology The weather condition is determined by the location of the area in relation to the fluctuating position of the Inter-Tropical Convergence Zone and the Inter-Tropical Front (ITF). The weather of BCA FDP area is influenced by these tropical continental and maritime air masses, which are associated with the north-east and the moisture-laden south-west winds, respectively. The climatic components of the project area are discussed below. Temperature and wind The average maximum and minimum temperatures measured in the field during the dry season was 29.8 o C and o C respectively while the maximum and minimum temperature ranges measured during the wet season were o C and o C. The existing climatic records obtained from the synoptic station indicate that EIA of Benisede Catchment Area FDP June, of 253

90 the mean ten years ( ) maximum temperature for dry season is for March, 28.5 for July and 32.1 for December. Full monthly maximum temperature for the last 20 years is shown in Table 4.1. Two main winds, southwest (SW) and the northeast (NE) winds are generally influential on the weather in the study area. However, a third wind, the North-South wind has also been reported in the area. The north south wind is known to be strongest during the dry season (November March). It accounts for about 32% of the annual winds within the Niger Delta area during this period. (NLNG, 1997). EIA of Benisede Catchment Area FDP June, of 253

91 Table 4.1: Mean Maximum Temperature in o C Jan. Feb. March April May June July Aug. Sept. Oct. Nov. Dec. Year Mean: Mean: Source: Federal Department of Meteorological Services, Oshodi, Lagos( now, Nigerian Metrological Agency) EIA of Benisede Catchment Area FDP June, of 253

92 Table 4.2: Monthly Total Rainfall Records in mm Jan. Feb. March April May June July Aug. Sept. Oct. Nov. Dec. Year TR TR TR xx xx TR TR TR EIA of Benisede Catchment Area FDP June, of 253

93 Source: Federal Department of Meteorological Services, Oshodi, Lagos( now, Nigerian Metrological Agency) EIA of Benisede Catchment Area FDP June, of 253

94 Chapter Six Table 4.3: Mean Monthly Temperature and Rainfall Records Location Time (hr) Relative Humidity (%) Max. Temp. ( o C) Min. Temp ( o C) Rain Fall (mm) Ojobo Amabolou Peretorugbene Torugbene Flowstation Source: Benisede Catchment Area FDP Baseline Study Report (Dec., 2002) Rainfall Within the BCA FDP area, rain falls throughout the year but over 80% of it occur in the months of May to September. The 25-year rainfall records ( ) indicate a mean rainfall of 373mm, 19.3 and 107.9mm for the months of July, December and March respectively. The single highest rainfall record is 840.9mm recorded in July (Federal Department of Meteorological Services, Oshodi, Lagos). Relative Humidity The average relative humidity recorded in BCA FDP area was 80.9% with sunny and cloudy weather in the dry season. However, the long term mean monthly relative humidity for the region at different times of the day show that higher relative humidity (RH) values are recorded at 0900 h for both wet and dry seasons. This warm humid climate and high relative humidity measured in the BCA FDP area is due to the seasonal variation of the Inter-Tropical Front and the geographical location of the Niger Delta. Wind Speed and Direction The predominant wind direction within the BCA FDP area is southwest (80%) and rarely northeasterly (20%) with low wind speed throughout the area. The wind speed within the BCA FDP area during the field study ranged from knots, with an average of 7.5 knots (Table 4.4). EIA of Benisede Catchment Area FDP Phase 2 June, of 253

95 Chapter Six Table 4.4: Wind Speed and Direction within BCA FDP Area (Dry Season) Location Wind Speed Wind Direction Weather Condition Time Hours Speed (knots) Time Direction Ojobo am 2 7.2knots 9.45a.m SW; NE SCW Peretorugbene pm 2 6.5knots 2.00p. SSW SCW m Torugbene am 3 7.5knots 10a.m SSW SSMB Flowstation Area pm 3 8.5knots 2.00p. SW SBW m Amabolou am 2 6.5knots 10a.m SW CW Key to Weather Condition SCW = Sunny and cloudy weather, SBW = Sunny and breezy weather, SSMB = Slightly sunny with moderate breeze CW = Cloudy weather Air Quality and Noise The results of in-situ air quality studies in the BCA FDP area are presented in Table 4.1a in Appendix III (dry season) and Table 4.1b Appendix III (wet season). The assessed solar and heat radiation values ranged from 0.0 to 1.85 kw/m 2 (dry season) and from <0.01 to 1.76 kw/m 2 (wet season). The most intense solar radiation (1.85 kw/m 2 in the wet season and 2.22 kw/m 2 in the dry season) were measured at the flowstation whereas the highest heat radiation value of 2.22 kw/m 2 was obtained from the flare site. The smoke density measured at the flare site was measured at 1.20 Ringlemann number. Other noxious gases measured are shown in Tables 4.1 (Appendix III). Volatile Organic Carbon (VOC) was not detected (below detectable limit, BDL) at all the sampling stations while SO x and NO x were within FMENV/DPR limits (Table 4.1 Appendix III). The noise levels measured within BCA FDP area ranged from 52.5 db (A) at Ojobo primary school to 93.5 db (A) at the flare site in the dry season. There was no significant variation in the noise levels measured in the wet season (Table 4.2 Appendix III). The recorded noise data are within tolerable limits of db (A) specified by FMENV and DPR. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

96 Chapter Six Soil, Agriculture and Land Use Studies Soil The most prevalent features of the soils within the BCA FDP area are those that are related to poor drainage and seasonal flooding. They are mineral soils formed on almost flat lowland areas. They belong to the freshwater alluvial deposits (Anderson, 1967). The texture of the soil in Benisede field is mainly sandy loamy. The amounts of colloidal particles (silt and clay) are small, leading to excessive leaching of nutrients in the soil. The mean soil ph value is 4.40 and strongly acidic. Electrical conductivity of the soil in Benisede field is low (mean: µs/cm) but suitable for most crops if recommended amounts of fertilizer are used. The total nitrogen contents could be due to the tide coverage of these soils, which prevent minerealization of organic matter into component nutrients. The concentrations of available phosphorus are low and below the 15.0ppm recommendation critical level. Agriculture Agriculture in the area is dictated by, climatic factors, soil properties and landscape features of the coastline. The locals in the BCA FDP area are mainly subsistence farmers and often practice mixed cropping. Crop combinations include cassava, yams, vegetables, maize and okra. Plantain, banana and cocoyam are also cultivated in the area. However, plantain and banana are observed to be scattered around the bushes while cocoyam is commonly planted on dredged materials along the banks of the creeks. Although the crops are cultivated in small scale in the area, they were observed to be flourishing, indicating the suitability of the soil for such crops. Fish farming is also a common agricultural practice in the area. Common fishing methods include: backwater netting, canoe drift netting and, hook and line. Both raphia palm and oil palm (Elaeis guineensis) are prominent in the BCA FDP area. The oil palms are harvested from wild groves. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

97 Chapter Six Physical Characteristics of soils within BCA FDP area S 0-15 cm Depth cm Depth o il Sample The physico-chemical characteristics of the soils within the BCA FDP area are reported in Table 4.3 in Appendix III. Soil Texture The soils of the BCA FDP area are generally coarse textured and sandy loam. The textural distribution varies from sand to sandy clay loam in both surface and subsurface soils. The mean clay contents is above 10 percent and 9 percent for surface and subsurface soils respectively while the silt content averaged 21 percent in both depths. The silt/clay ratios indicate that the soils are made up of young parent materials with low degree of weathering (Van Wambeke, 1962; Asomoa, 1973; Edem and Ndon, 2001). These results show that the soils are likely to have weatherable minerals needed for plant nutrition. Plate 3: Soil sampling using a hand-held auger EIA of Benisede Catchment Area FDP Phase 2 June, of 253

98 Chapter Six Table 4.5: Particle Size Distribution in Soils of BCA FDP area Sand % Silt % Clay % Textural class Sand % Silt % Clay % Textural class SS S S SS S S SS SL SCL SS SL SL SS SL SL SS S S SS SL SL SS S SCL SS SCL SCL SS SCL SCL Range Mean SL SL Silt/Clay Ratio S = Sand, SL = Sandy Loam, SCL = Sandy Clay Loam Chemical characteristics of soils within BCA FDP area The chemical properties of soils within the BCA FDP area are presented in Tables 4.3 (Appendix III). Soil ph The soils are strongly acidic with mean ph values of 5.4 and 5.2 for surface and subsurface soils respectively. The high acidity may have resulted from the dominance of acidic cations, which is the characteristic of soils with kaolinites (1:1) and oxide clays. The strong acidity will influence the availability of basic cations and hence the productivity of the soil. Cation Exchange Capacity (CEC) The CEC is low with mean values of 6.43 and 6.33 meq/100g for surface and subsurface soils respectively. The values are however higher in the surface soil than the subsoil. This may be due to the presence of organic materials or litters on the surface soil. The low CEC indicates low soil fertility. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

99 Chapter Six Organic Carbon, Total N, C:N Ratio and Available Phosphorus The organic carbon contents are low in both depths (0-15cm and 15-30cm). The values are higher in the surface soil than the subsoil Tables 4.3 (Appendix III). The mean values are 0.99 and 0.48 percent for surface and subsurface respectively. The higher value for the surface soil may be due to the presence of organic materials, litters and this is also the zone of maximum root activity (Donahue et al, 1983, Wahden et al, 1984; Edem and Ndon, 2001). Similarly, the total N is low with mean values of percent for surface and subsurface soils. The C:N ratios were recorded as 2.4 (surface) and 3.3 for subsurface. The soils have low available phosphorus (P) with mean values of 3.74 and 2.89 mg/kg for surface and subsurface soils respectively. Like the organic carbon content, the values are higher in the surface soil than the subsoils. This is because available P is known to be associated with organic matter (Ibia, 1994; Edem and Ndon, 2001). Electrical Conductivity The values ranged from 20.8 to 96.4µs with a mean value of 66.89µs for the surface soil and from 20.4 to 91.5 µs with a mean value of µs for the subsoil. The mean values were higher in the surface than the subsoils. Chloride The chloride content varied from 144 to 1027 mg/kg with a mean value of mg/kg for the surface soils and from 123 to 1021 mg/kg with a mean value of mg/kg for the subsurface soils (Tables 4.3 in Appendix III). The mean value is higher in the surface soil than the subsoil. The presence of chloride in soils is known to influence the uptake of some nutrients, for example phosphorus. Total Hydrocarbon (THC) Contents The THC contents ranged from 0.68 to 7.10 mg/kg with mean value of 3.52 mg/kg for the surface soils and from 0.71 to 6.24 mg/kg with a mean value of 3.41 mg/kg for the subsurface soils (Table 4.3 Appendix III). The low values may indicate that the hydrocarbons in the soil are biogenic and not petrogenic in origin (Chemical Society of Britain, EIA of Benisede Catchment Area FDP Phase 2 June, of 253

100 Chapter Six Heavy Metals The heavy metal content of soils within the BCA FDP area is reported in Table 4.3 (Appendix III). Iron is the most abundant with a range of mg/kg and mean value of mg/kg for the surface soils while the range for the subsoil is mg/kg with a mean value of mg/kg. Generally, the values are within the range for mineral soil environment (Bohn et al, 1979). However, their impacts as to the degree of contamination can be highly significant due to the local edaphic condition. Detection of petroleum associated heavy metals such as nickel (Ni) and vanadium (V) confirms that the soil environment must have been impacted by crude petroleum. This may result from operational or accidental spill of crude petroleum from well-heads or burst flowlines. Such spills may be spread by flood on a large area of the low-lying soils. Soil microbiological analysis The heterotrophic bacterial count of soil samples of the BCA FDP area varied from 1.3x x cfu/g with a percentage hydrocabon biodegraders range of nil to 2.1% in the dry season (Table 4.7 Appendix III). The predominant bacterial communities in the soil samples of the BCA FDP area were composed of Pseudomonas auriginosa, Proteus mirabilis; Micrococcus sp; Bacillus subtilis; Eschericha coli; Klebsiella sp. (Table 4.7 Appendix III). The hydrocarbon degraders were mainly species of Bacillus, Klebsiella, and Pseudomonas. In the wet season, heterotrophic bacterial count of soil samples of the BCA FDP area varied from 1.6x x cfu/g with a percentage hydrocabon degraders range of 0.00 to 1.27%. The fungal counts of soil samples of the BCA FDP area were low and ranged from 1.0 x 10 4 to 3.5 x 10 7 cfu/mg (Table 4.8 Appendix III). The counts of hydrocarbon degraders are low with their associated low percentages ( %). The predominant fungal isolates were mainly species of Mucor, Candida, Saccharomyces, Cladosporiump, Penicillium and Aspergillus. In the wet season, similar trend was observed (Table 4.8 Appendix III). EIA of Benisede Catchment Area FDP Phase 2 June, of 253

101 Chapter Six Vegetation / Land use Vegetation Profile The vegetation of BCA FDP area is generally homogenous and composed mostly of two layers of vegetation strata, namely the tree and shrub/herb layers. The tree layer is composed mostly of pure stands of Raphia hookeri with only scattered freshwater swamp forest tree species. Plate 4: Brass Creek A major drainage feature in the study area (also showing a palm bush) Common plant species within the study area include: Raphia palms, Symphonia globulifera and Pterocarpus santalinoides, Bambusa vulgaris (bamboo), Elaeis guineensis (oil palm), Anthocleista vogelli (Cabbage tree), Mitryagyna stipulosa (Abura) Alchornea cordifolia (Christmas bush), which is characteristic of Swamp forests of Southern Nigeria.. The tree layer was dominated by Raphia hookeri while the herb layer was dominated by ferns (Cyclosorus sp. and Diplazium sammatii) and the arrow-head weed, Cryptospermum senegalense. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

102 Chapter Six The vegetation of the BCA FDP area is generally a freshwater fringe forest type with canopy heights of between 5-8 metres. The vegetation also consists of emergent tree species reaching up to 15 metres in some cases. The vegetation cover is between 60-80%, with patches of bushes resulting from farming activities (newly cleared farm plots, cultivated farmlands and abandoned or fallow farm plots). A major distinguishing characteristic of the forest in this area is the dense tangle of lianas and other climbers. (NEST, 1991) Land use types and Floristic Composition There are four distinguishable landuse types within the BCA FDP area. They are: (i) Built-Up (ii) Farmlands/Home gardens, (iii) The freshwater swamp forest, and (iv) Water Bodies. Built Up These consist mainly of towns, villages, fishing settlements and Oil and Gas facilities within the study area. The major towns and villages in the area include: Ojobo, Peretorugbene, Tamogbene, Amabolu and Norgbene. and Akarino. There are also small fishing settlements spread along the banks of the creeks. Oil and Gas facilities in the area include a flowstation, wellheads, pipelines, a helipad and two houseboats. The built up area make only about 6% of the total land use of the area. Farmlands/Home gardens The floristic composition of the farmland/home gardens species, which incidentally reflect the herbaceous components of the vegetation are presented in Table 4.6. The major herbaceous and grass species are Pennisetum purpureum, Pennisetum polystachion, Hyperrhenia sp, Ageratum conizoides, Aspilia africana, Chromolaena odorata and ferns, Pteris sp and Dryopteris sp. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

103 Chapter Six Plate 5: A farmland in the study area The farmlands/home gardens, which constituted about 15% of the vegetation found especially at the edges of the creeks/slots, had crops such as cassava, plantain, sugar cane, cocoyam, potato and medicinal plants (e.g. Bryophyllum). EIA of Benisede Catchment Area FDP Phase 2 June, of 253

104 Chapter Six Table 4.6: Agricultural Landuse types with commonest plant species Landuse Type Farmlands /Home gardens. Freshwater swamp forest Commonest Plant Species Zea mays, Vernonia amygdalum,musa paradisiaca, M. sapientum, Manihot esculenta, Xanthomonas sp., Colocasia sp., Saccharum officinarum, Ipomoea batata, Carica papaya, Capsicum anuum, Dioscorea alata, Hibiscus esculenta. Bryophyllum pinnatum, Cassia alata. Panicum laxum, Echinochloa pyramidalis, Axonopus compressus, Saciolepis sp., Phyllanthus amarus, Chromolaena odoratum, Acroceras sp., Ageratum conyzoides, Pennisetum purperum, Commelina benghalensis, Heliotropium indicum. Raphia hookeri, Anthocleista vogelli, Mitragyna stipulosa, Elaeis guineensis, Musanga cercropioides, Alstonia boonei, Ciba pentandra, mytragyna ciliata, calamatus decratus, Uapaca stuadtii, berlinia, Pandanus, togoensisnapoleonaea vogelli. Raphia hookeri, Alchornea cordifolia, Funtumia elastica, Baphia sp., Spondias mombin, Cassia alata, Ficus sp., Macraranga spinosa, Lophira alata, fiscus congensis, Ceiba pentandra, Cesestis afzelii, Asplenium africanum, Ancistrophyllum sp. Cassia alata, Baphia sp., Elaeis guineensis, Raphia hookeri, Chromolaena odorata, Capsicum sp. Piper sp., Pennisetum purpureum, Bryophyllum sp., Dioscorea sp., Smilax kraussiana. Costus afer, Aframomum sp. Commelina benghalensis, Axonopus compressus, Panicum laxum, Acroceras sp., Saciolepis sp., Echinochloa pyramidalis. Phyllanthus amarus, Heliotropium indicum, Chromolaena odorata, Ageratum conyzoides, Pteris sp., Cyclosorus sp. Diaplazum sammattii Life-Form/ Plant status Crop plants Medicinal plants Weeds crop farms on Microphanero -phytes Mesophanerophytes Nanophanerophytes Chamaephyte s Cryptophytes Hemicryptophytes Therophytes Epiphytes % Abundance 10% 75% EIA of Benisede Catchment Area FDP Phase 2 June, of 253

105 Chapter Six Aquatic Macrophytes Eichhornea crassipes, Azolla africana, Pistia stratiotes, Slavinia molesta, Lemna sp. Free floating Nymphea lotus. Floating leaf type Cyrtospermum senegalense, Echinocloa pyramidalis, Saciolepis sp., Alternanthera sessielis, Aeschyonomene indica, Vossia cuspidata. Bank type 15% The freshwater swamp forest The freshwater swamp forest account for about 60% of the total land use of the study area. The forest vegetation can be classified into three plant species groups, that is Hemicryptophytes, therophytes and epiphytes. It is predominated by Palm trees (Eleias guneensis), Rafia palm (Raphia hookerii), Umbrella plant (Musanga cerclopoides and Alstonia bonnei). Alchornea cordifolia forms the main bush/shrub species, occassionally accommodating clusters of Banana, Plantain, the rubber plants (Havea sp) and Coconut (Cocos nucifera). Some cultivated species of Guava, Mango (Mangifera indica) and bush mango (Irvingia gabonensis) were also present especially near the settlements/villages or towns. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

106 Chapter Six Plate 6: Farming on dredge-spoil along bank of Bomadi Creek In elevated areas due to dredge spoil dumped along the slots, grasses such as Pennisetum purpureum, Saciolepis, Cyclosorus, ferns and members of the Araceae family (eg. Cryptospermum senegaleuse) dominated the herb stratum. These dredge spoil dumps are used for cultivation of plantain, musa paradisiaca and cocoyam, Xanthosoma sagittifolium. Aquatic Macrophytes The slots to the wellheads within the BCA FDP area are covered by aquatic macrophytes creating difficulty to boat traffic from local fishermen. The aquatic macrophytes of the BCA FDP area include Echinochloa sp, Azolla africana, Pistia stratiotes and Nymphea lotus. Species such as Cryptospermum senegalense, Vossia arspida and Saclolepsis sp were also observed. The aquatic macrophyte population of the BCA FDP area was dominated by Eichhornea crassipes (water hyacinth), Vossia cuspidata, (grass) Echinocloa sp (grass) Pistia stratiotes (water lettuce) and Salvinia molesta (aquatic fern). Others were Azolla africana, Lemna sp, Saclolepis sp, Alternanthera sessielis, Aeschyonomene indica and Cyrtospermum senegalense. They were concentrated in the slots more than in the creeks and creeklets. There was high species diversity and density of these aquatic macrophytes encountered within the BCA area and thus has the potential to develop into excessive populations that can cover the entire water surface of the wellheads slots. The relative abundance of the different groups of plant species within the study area (BCA FDP area) indicates that Firm Soil plant species constitute about 75% of the vegetation; the aquatic macrophytes constitute 15%, while the farmland/home gardens form 10% of the vegetation Plant Species Diversity of the BCA FDP Area The plant species diversity of the BCA FDP area are summarized in Table 4.7. The mean plant density in the herbaceous layer was 62 No./m 2 in the fresh water swamp, 345 No./m 2 of aquatic macrophytes and Farmland species had 20 No/m 2. The tree and shrub cover showed a density of 565 No./ha and 4620 No./ha in the swamp forest and farmlands, respectively. Epiphytes were observed on the palm trees. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

107 Chapter Six The species diversity index was for the Freshwater swamp and the aquatic species and for the Farmland species. Table 4.7: Plant Species diversity and agricultural landuse Vegetative/Agricultural landuse type Freshwater swamp MEAN PLANT DENSITY Species Diversity Index Herbaceous layer (No./m 2 ) 62 Tree and shrub or crop layer (No./ha) Aquatic Macrophytes Farmlands Pathological Studies The vegetation in BCA FDP area presents a generally healthy bill though with a few cases of disease prevalence e.g, Sigatoka on plantain (Musa paradisiaca) and rust on raffia and oil palm. The Chlorophyll content is expressedly high, occassioned by the absences of leaf yellowing and/or chlorosis. Leaf damage resulting from the defoliation by insects was however noticed. Disease symptoms and the severity indices, as well as causative agents are presented in Table 4.8 The oil and raffia palms had the rust disease with very light disease severity indices (Table 4.8). Few populations of the arrowhead weed (C. senegalense) had the mildew disease. The Musanga plants as well as the Hibiscus esculenta had moderate to severe infection as shown in the defoliation of the plants caused by the larva of insects EIA of Benisede Catchment Area FDP Phase 2 June, of 253

108 Chapter Six (caterpilar). The plantain and banana plants also had moderate to severe infections of sigatoka disease and this affected the sizes of bunches from the plants. The pathogens were however limited in their occurrence and did not pose any threat to the healthy appearance of the general vegetation. Table 4.8: List of Plant Species/disease analysis within BCA FDP Area Plant species Disease symptoms Disease severity Index Identified agents causative 1. Freshwater swamp forest Elaeis guineensis Rust 1 Curvularia sp. Alchornea cordifolia Leaf spots 2 Cercospora sp. Musanga cercropioides Defoliation 3 Larvae (Cartepillar) of Insect Raphia hookeri Rust 2 Curvularia sp 2. Aquatic macrophytes Vossia cuspidata Leaf spots 2 Puccinea graminis Cyrtospermum senegalense 3. Farmlands Manihot esculenta Cassava mosaic disease Sooty Mildew 2 Erysiphe sp. 1 Virus Musa paradisiaca Sigatoka 3 Mycosphaerella musicola Ipomoea batata Leaf spots 2 Cercospora sp Musa sapientum Sigatoka 2 Mycosphaerella musicola Saccharum officinarum Rust 1 Curvularia sp. Hibiscus esculenta Defoliation 2 Larvae (Cartepillar) of insect Plant Tissue Analysis EIA of Benisede Catchment Area FDP Phase 2 June, of 253

109 Chapter Six The results of plant tissue analysis from BCA FDP area are presented in Table 4.4 (Appendix III). The values were within normal/standard acceptable limits. However, ferric ion concentration was quite high (76.65ppm) in Cryptospernum senegalense. This is not unexpected because of the tendency of this plant to accumulated ferric ion in its tissues. The value was still within non-dangerous limits. The result of plant tissues assessment of matured leaves usually reported for the area indicates that the range of concentrations of N, P and K, are mg/l, mg/l and , respectively. Other parameters are presented in Table 4.4 (Appendix III) Wild Life / Biodiversity Studies: The wildlife observed and sighted in BCA FDP area during the field study include Insects, Molluscs, Amphibians, Reptiles, Birds (Aves) and Mammals. The wildlife types encountered are presented in Table 4.9. The inventory of invertebrate fauna was diverse and consisted of forest dwelling species dominated by ants, beetles and millipedes. Many genera and species of arthropods were recorded. Ants, flies, butterflies and grasshoppers were a common feature within BCA FDP area. Some species of bugs, dragon flies and damselflies were also recorded. The mollusca fauna was represented by the presence of the giant African land snail, Archachatina marginata suturalis and the garden snail, Limicolaria aurora. Freshwater periwinkle, Tympanotonus fuscatus were also predominant in the BCA FDP area. Most of the mammals are crepuscular, feeding in the early hours of the day or just before dusk. Rodents and pottos dominated the mammalian class. Forest dwelling species in the swamp area and, seed and insect-eating species in the developed area dominated avifauna of the BCA FDP area. The bird species recorded by sighting, nest observations and call sounds include the white egrets, kites, weaverbirds, owls and hawks. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

110 Chapter Six Different species of reptiles and amphibians were also noticed. Prominent among these were Agama agama (Common lizards), monitor lizards, Gecko, frogs and Snakes. Table 4.9: List of Wildlife species within the BCA FDP Area Taxa Common names Scientific names Phylum Arthropod Dictyoptera Cockroachers Blatella sp Gryllidae Crickets Gryllus sp Gastropoda Water snail Lymnea sp Water snail Physa sp Giant African land snail Archachatina marginata suturalis Garden snail Limicolaria aurora Periwinkle Tympanotonus fuscatus Amphibians Frog Dicroglossus sp Frog Ptychadaena sp Toad Buforugularis Toad Xenopolis sp Reptiles Lizard Agama agama Skink - Gecko - Snake - Birds (Aves) Cattle egret Egretta garzetta Senegal fire-finch Lagonstica senegala Forest robin Cercotrichas leucostcta Turtle dove Streptopelia semitorquata White-faced owl Accipiter badius African swift Collectoptera affinis. Palm swift Cypsiurus parvus Carrier Hawk Polyboroides radiatus EIA of Benisede Catchment Area FDP Phase 2 June, of 253

111 Chapter Six Mammalia (Mammals) Village weaver Red eyed dove Common bulbul West African River Eagle Hornbill Yellow wagtail Giant rat Potto Mona monkey White-bellied pangolin Ploceus cucullantus Streptopelia semitorquata Pydnonotus barbatus Haliaetus vocifera Lophoceros semifasciatus Budytes flavus Rattus sp Perodictius potto Cercopithecus mona Manis tricuspts AQUATIC STUDIES Surface Water Quality The major surface water bodies in the project area are Bomadi and Brass Creeks. The results of the physico-chemical parameters of surface water samples from the BCA FDP area are presented in Table 4.5 Appendix III. In-situ measurements of the temperatures of the surface water within the BCA FDP area ranged from 21.8 to C with a mean of C. Turbidity values varied between 2.1NTU and 56.0 NTU. Total dissolved Solids varied from 30.5 to 110.8mg/l and electrical conductivity values were between 26.7 and 99.2mg/l. The ph values indicated a weak acidic range of values (ph ) while Bicarbonate values ranged from 0.56 to 3.31mg/l. The Chloride concentrations varied from 26.8 to 99.2mg/l. Chemical Oxygen Demand (COD) values ranged from 3.7mg/l to 15.3mg/l. Dissolved Oxygen values ranged from 4.42 to 5.09mg/l while Biochemical Oxygen Demand (BOD) values ranged from 0.85 to 1.21mg/l. The concentrations of Na +, K +, Ca ++, and Mg ++ ions are as follows: 2.51mg/l to 5.74mg/l; 1.87mg/l to 8.74mg/l; 4.87mg/l to 27.29mg/l and 1.83mg/l to 4.34mg/l respectively. The heavy metal concentrations were generally low. The concentrations of the Total Hydrocarbon Content (THC) were also low (<0.50mg/l). EIA of Benisede Catchment Area FDP Phase 2 June, of 253

112 Chapter Six Phytoplankton Studies The phytoplankton community of the surface water within the BCA FDP area comprised of 32 taxa belonging to the Divisions Bacillariophyta (16 species); Chlorophyta (6 species); Cyanophyta (3 species) and Euglenophyta (7 species). The diatoms (Bacillariophyta) were the most prevalent followed by the Euglenoids while Microcystis (Cyanophyta) was the most dominant blue-green species being present in all the stations in the BCA FDP area. Zooplankton Studies The zooplankton community of the surface water within the BCA FDP area was mainly arthropods and rotifers. The arthropods were made up of cladocera, Conchostraca, Ostracoda and Copepoda. Bosmina longirostris and Bosminopsis dietersi were prevalent among the cladocerans. The Ostracoda was represented by Parastenocypris sp, Stenocypris sp and Cypridopsis. The Cyclopoids were dominant among the copepods. The Rotifera were represented by five families and eleven species dominated by members of the family Brachionidae. (Brachionus fulcatus, Brachionus tripos, Keratella tropica, Ceptialodella, Tricocerca, Kelicotia, Lepadella ovalis, Lecane lutia, Anuraeopsis fissa) Microbiological Studies The heterotrophic bacterial count of water samples of the BCA FDP area varied from 1.1 x 10 6 to 12.5 x 10 6 cfu/ml with low percentage of petroleum degraders (0.01 to 0.90%) in the dry season. The counts were within the range usually obtained from unperturbed environment ( cfu/ml) (Table 4.9 Appendix III). The predominant bacteria species in the water bodies of the study area were Bacillus sp, Staphylococcus sp, Pseudomonas sp and Escherichia sp (Table 4.9 Appendix III). However, in the wet season the heterotrophic bacterial count of water samples of the BCA FDP area varied from 1.3 x 10 6 to 12.1 x 10 6 cfu/ml with low percentage of petroleum degraders (0.1 to 0.9%). Apart from WS 14 where no fungal growth was observed, the fungal counts of water samples from the BCA FDP area ranged from 3.1 x 10 5 to 9.8 x10 5 cfu/ml in the dry season (Table 4.10 Appendix III). During the wet season, the fungal counts of water EIA of Benisede Catchment Area FDP Phase 2 June, of 253

113 Chapter Six samples from the BCA FDP area ranged from 3.1 x 10 5 to 8.2 x10 5 cfu/ml. The predominant fungal isolates in water samples within the BCA FDP area were Mucor sp, Cladosporus sp Penicillium sp and Candida sp. The low ratio of microbial counts to petroleum degraders of below 1.0% indicates that there has been no previous crude oil input into the water of the BCA FDP area in recent times. Fisheries Studies The main occupation of the people inhabiting the field is fishing. Fishing is extensively carried out by the host communities for domestic consumption as well as for commercial purposes. Fishing gears include fish traps, conical baskets, hooks and lines, cast nets, sweep nets and drag net of various mesh sizes. Shellfishes include shrimps of the families Penaeus notialis (Pink shrimp) and Parapaenopsis longirostris (Royal shrimp) and the commercially important bivalve mollusc (Egeria paradoxa) which were mostly picked up by divers operating from dug-out canoes along the Bomadi and Brass creeks. Fish observed in their natural environment or bought from the fishermen operating along the creek belonged to the orders Characiformes, Cypriniformes, Osteoglossiformes, Siluriformes and Perciformes. A list of the fish species of the water within the BCA FDP area is presented in Table Analysis of the condition factors of the fish species of the water within the BCA FDP area showed that the fishes were healthy and well fed in a relatively unperturbed environment. The condition factors were on the average well above 1.0 (the critical value). The species diversity as well as the density was high. All the fishes examined did not show any physical evidence of parasitic infestation. There were also no observation of disease infestation and abnormalities. Table 4.10: A list of the commonest fish species within BCA FDP Area FISH CLASSIFICATION FAMILY Order Characiformes Hepsetidae, Hepsetus odoe, Citharinidae, Citharinus citharius. Abundance 4 Order Cypriniformes Cyprinidae, Barbus batersii 3 Order Osteoglossiformes Osteoglossidae, Heterotis niloticus, 2 Gymnarchidae, Gymnarchus niloticus. Order Perciformes Cichlidae, Sarotherodon galiaeus, Tilapia marie, T.zilli. 4 EIA of Benisede Catchment Area FDP Phase 2 June, of 253

114 Chapter Six Order Siluriformes Bagridae, Chrysichthys, nigrodigitatus, Clariidae, Clarias buthupogon Mochokidae, Synodontis clarias Schilbeidae, Physailia pellucida 3 Order Mugiliformes Mugilidae,Mugil curema, Liza falcipinnis 3 Order Protopteriformes Protopteridae, Polypterus aneectens 2 Order Momyriformes Momyridae, Gnathonemus petersii, momyrus deliciousus, momyrus rume, marcusenius psittatus Order Carangiformes Caranx hippos, caranx senegalensis 2 Order Schilbeiformes Schilbe mystus, Eutopius niloticus 1 3 Plate 7: Tilapia zilli caught at the Benisede Flowstation area Sediment Studies EIA of Benisede Catchment Area FDP Phase 2 June, of 253

115 Chapter Six Physico-chemical characteristics The results of physico-chemical characteristics of the bottom sediments of the BCA FDP area are presented in Table 4.6 (Appendix III). The ph of the sediment is acidic with values ranging from 5.2 to 6.3. Texture of the sediment varied from loamy sand to sandy loam, with low nitrate values ranging from 0.01 to 2.71ppm, the percentage total nitrogen values ranged from These values are low, and this indicates active mineralization of organic matter due to decomposition activities. Available phosphorus concentration varied from 0.4 to 6.1mg/kg. Exchangeable cations Ca, Na, Mg and K have values ranging respectively from ( mg/l), ( mg/l), ( ) and ( mg/l). The results of the heavy metal of the bottom sediments of the BCA FDP area are presented in Table 4.6 (Appendix III). The values are generally high indicating a concentration/accumulation of these ions /metals in the sediment. Macrobenthic invertebrates The predominant macrobenthic invertebrates communities of the BCA FDP area are mostly the fauna inhabiting the bankroot biotope. The Benthic organisms were represented by the bivalve, Egeria paradoxa. The macrobenthic invertebrates consisted of 11 taxa belonging to the Phyla Annelida (2 taxa), Arthropoda (7 taxa), Mollusca (1) and Chordata (1). The annelids were represented by Dero sp while the arthropods were represented by Caridina africana (decapod); Hydrophilus picus and Dysticus sp. (Coleoptera). Cryptochironimus (Diptera), Somatochlora metallica (dragon fly nymph), Beatis sp (Ephemeroptera), and Edyonurus sp. The density and diversity of the Macrobenthic invertebrate were generally low throughout the BCA FDP area Microbiological Studies The heterotrophic bacterial count of the sediment samples within the BCA FDP area ranged from 11.8x10 8 to 25.4 x 10 8 cfu/g with low counts of petroleum degrading bacterial isolates and hence low heterotrophic bacterial count to crude oil degraders of less than 1.0% (Table 4.11 Appendix III) in the dry season. In the wet season, the heterotrophic bacterial count of the sediment samples within the BCA FDP area ranged from 11.8x10 7 to 26.2 x 10 7 cfu/g (Table 4.11 Appendix III). The EIA of Benisede Catchment Area FDP Phase 2 June, of 253

116 Chapter Six predominant bacterial isolates from sediment samples within the BCA FDP area for both seasons were Bacillus sp, Pseudomonas sp, and Staphylococcus sp. The fungal count ranged from x 10 6 g. The percentage hydrocarbon degrading fungi varied from % in the dry season, while the fungal count ranged from 2.55 x 10 6 to 5.24 x 10 6 (Table 4.12 Appendix III) with petroleum degrading fungal ratio of less than 1.0% (Table 4.12 Appendix III) in the wet season. The low ratio of microbial counts to petroleum degraders of below 1.0% indicates that there has been no previous crude oil input into the sediment of the BCA FDP area in recent times Geology/Hydrogeological Studies Geology of the Area The BCA FDP area lies within the Niger-Delta, its geology is therefore typical of the Niger Delta Basin. The area forms part of a geological sequence of the Quaternary and Tertiary formations of the Niger-Delta, consisting mainly of three main geologic formations, which are: The Benin Formation; The Agbada Formation; and The Akata Formation. The Benin Formation: This is the topmost layer (Oligocene-Recent), which extends its limit from West to East side across the entire Niger Delta area and Southwards beyond the present coastline. The formation is composed of 90% sandstone with shale intercalations. Its thickness is variable but generally exceeds 1800 meters. The Agbada Formation: This underlies the Benin Formation and consists of sandstone and shales. It consists of an upper predominantly sandy unit with minor shale intercalations and lower shale unit, which is thicker than the upper one. The age range on the Geologic Time Sequence is Oligocene to Recent. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

117 Chapter Six The Akata Formation: (Eocene to Recent). It is over 1200m thick, consisting of discontinuous/undulating clay unit of marine shales probably occurring as lenses. Overlying these three sequences within the Niger Delta are various Quaternary deposits or geomorphologic units. Within the BCA FDP area, there are deposits and meander belts, which are abandoned, meander loops and extensive point bars. It is capped by natural levees with the crevasse deposits typifying flood plains. VES Data and Interpretation Below are the descriptions for each shot point for the five VES stations established within the BCA FDP area. VES 1 The response VES curve for this station is a KHA type. Computer iterative interpretation reveals a four-layered geoelectric model with first layer having a resistivity of 545Ω corresponding to a sandy clay layer. The second layer has a resistivity value of 342Ω corresponding to a sandy layer. Other resistivity values obtained correspond to sandy formation. VES 2 The response VES curve for this station is a KQA type. Computer iterative interpretation reveals a three-layered geoelectric model with first layer having a resistivity 823.5Ω corresponding to a top sandy -silty -clay soil underlain by a clay unit. The unit overlies a dry weathered sandy unit, while the rest of the geoelectric substrata are likely to be sandy units. VES 3 The ABEM response VES curve for this station is a KH type. Computer iterative interpretation indicates four geoelectric layers. The first layer is the sandy topsoil underlain by clayey layer that is made up of geoelectric layers 2, while geoelectric layer 3 consist of stratified sand units with resistivity values ranging from 185 to 580Ω. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

118 Chapter Six VES 4 The ABEM super VES curve indicates an AHK type. The curve shows an undulating manner of increasing apparent resistivities. The computer iterative interpretation modeled a three-layered substratum. The first layer could be interpreted as sandy topsoil. The topsoil is underlain by the second layer, which corresponds to a clayey layer with resistivity value of 582Ω. VES 5 The ABEM super VES curve indicates a KHA type. The curve shows a bowl-bell segment indicating lower resistivities. The computer iterative interpretation indicates that the first two layers are possibly sandy topsoil underlain by clayey substratum. Hydrogeology/Ground Water Quality The stratigraphy of the ten-drilled boreholes revealed a fine to medium grained unconsolidated sands intercalated with clay lenses and iron sheen. The lithology as observed within the BCA FDP area are known to have resulted from the combined forces of depositional actions of the nearby Atlantic Ocean and the currents of the Bomadi/Brass rivers and their tributaries draining the area. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

119 Chapter Six Plate 8: Drilling new groundwater monitoring borehole at Opomoyo. The aquifers were not confined and the ground to water depth varied from 4 to 6m and the direction of groundwater flow is from East to west towards the Brass creek. The groundwater quality assessment indicated a ph range of 6.3 to 6.7. Electrical conductivity values were generally high (347.5µS/cm to µS/cm) indicating that the groundwaters were fresh to slightly brackish. The borehole water had moderate turbidity values of NTU. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

120 Chapter Six Plate 9: Flushing existing groundwater monitoring boreholes at the Benisede flow-station. Sodium, Potassium, Calcium and Magnesium concentrations are 27.60mg/l, 18.30mg/l, 32.30mg/l and 21.40mg/l, respectively. The results of the heavy metals analysis indicate values for Fe, Zn, Cu, Cr, Mn and Cd as 1.45mg/l, 0.45mg/l, 0.05mg/l, 0.32mg/l and 0.01mg/l, respectively. THC values ranged from 0.06mg/l to 0.42mg/l Social and Health Impact Studies Introduction Major communities within the BCA FDP area are Ojobo in Burutu Local Government Area of Delta State and Peretorugbene, Tamogbene Oweigbene, Norgbene and Amabolou in Ekeremor Local Government Area in Bayelsa State. Social Impact Studies Demography The estimated population of the communities within the BCA FDP area is 37,468 (1991 population census) people. The average annual growth rate of Nigeria s population was put at 2.83% by the 1991 population census and based on this growth rate, the 1996 EIA of Benisede Catchment Area FDP Phase 2 June, of 253

121 Chapter Six population was projected to be 44,029. Some of the communities within the BCA FDP area studied include Ojobo (7,204 people), Peretorugbene (9,037 people), Tamogbene (375 people), Amabolu (4,778 people), Norgbene (2,401 people) and Ekeremor (10,393 people). The 1991 population census figures of the area are presented in Table Table 4.11: BCA community population Community Males Females Both 1996 Projection Ojobo 3,535 3,669 7,204 8,212 Peretorugbene 4,750 4,287 9,037 10,695 Oweifagbene & others Tamogbene camp & others Amabolou 2,472 2,306 4,778 5,655 Ekeremor 5,449 4,944 10,393 12,300 Norgbene 1,305 1,096 2,401 2,842 Obirigbene III Foutoragbene II ,007 1,192 Agalawegbene & others Oweigbene & others Source: 1991 Population census of Nigeria The demographic profile (Table 4.12) shows that 58.6% of the population studied are males while 41.4% are females. About 39.8% of the population sampled are less than 15 years with age group 5-9 years being the most populated (14.9%). This demographic profile shows that the communities are dominated by youths and there is high level of dependency in these communities. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

122 Chapter Six Table 4.12: Demographic profile of the BCA FDP Area Age (years) Male (%) Female (%) Total (%) Cumulative (%) & above Total (%) The family size distribution of the communities within the BCA FDP area (Table 4.13) showed that 33% of the respondents have a family size of 5-8 people, 21% of the respondents have 1 4 people and 46% of the respondents have above 8 people. These values show that the communities have a larger family size. Table 4.13: Family Size Distribution of Communities within the BCA FDP area Family Size (Range) % Respondents Above Total 100 Ethnography Peretorugbene and Ojobo are the major communities that own Benisede fields. They are homogeneously Ijaw, a major ethnic group in the Niger Delta region. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

123 Chapter Six Plate 10: Consultation with communities (Ojobo) The Ijaws whose settlements are restricted to the coastal belt, claim to have descended from a common ancestor that migrated from Benin Aboh in the hinterland. The cause of this migration connected with political intrigues for which the Benin Kingdom was famous. From Benin Aboh, the Ijaw ancestor is said to have originally settled at Otuokpodu in Bayelsa state from where all other settlements were founded to the east and west. The reasons for this movement away from Otuokpodu include both political intrigues, rivalry for fishing areas and shortage of land, amongst others. This is a recurrent problem among the Ijaws to date. Streams of emigrants are said to have left Otuokpodu to found 32 other settlements, 18 in Bayelsa State and 14 in Delta State. Constant emigration and founding of new settlements now constitute Ijaw social life. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

124 Chapter Six AMABOLU, THE HEADQUARTERS OF OPOKUDO CREEK LGA IN BAYELSA STATE MIGRATED FROM OTUOKPODU ON ACCOUNT OF RIVALRY FOR FISHING AREA. AMABOLU (MEANING A TOWN LOCATED IN THE CREEK) IS ACCLAIMED TO BE THE ANCESTRAL ROOT OF ALL COMMUNITIES IN OPOROMOR KINGDOM, THE SEAT OF THE PEREKERE (KING) AND THE HEADQUARTERS OF THE FAMOUS EGBESU DEITY. PERETORUGBENE, A SETTLEMENT IN THE BRASS CREEK IS SAID TO HAVE BEEN FOUNDED BY FUOKEREGHA, A DESCENDANT OF THE AMABOLU MONARCHY WHO HAD MANY SONS INCLUDING ODOH, SANAH, EKANBARA, ESIEMOGHARI, DAUNEMIGHA AND TWO WOMEN, TOLU AND EKIERE. EKERE, THE FOUNDER OF OJOBO, IS SAID TO HAVE MIGRATED WESTWARD FROM AMABOLU WITH HIS CHILDREN AND NEPHEW NAMED GBESA TO SETTLE IN ORU EKEREMO FOU, NOW KNOW AS EGBEMA ANGALABIRI MARKET (FOU). LATER, GBESA MOVED FURTHER WESTWARD WITH HIS CHILDREN AND SETTLED AT KRISE CREEK. WHEN ONE OF HIS CHILDREN WAS SAID TO HAVE DIED AT BOLOU-OJOBO, HE LATER MOVED TO FOUND ADAGBASA AND ASAKUSA ON THE BOMADI CREEK. A FURTHER MIGRATING STREAM MOVED FROM BOLOU OJOBO TO FOUND ADAGBA, NOW OJOBO TOWN IN THE FOLOU TORU MAIN CREEK. THE NAME OJOBO WAS DERIVED FROM THE BEAUTIFUL BRASS COLOUR OF THE WATER (OJOBOYE- OGU). Culture Culturally, the Ijaws are a patrilineal people with strong emphasis on monarchy. There is a very strong filial relationship with extensive extended family ties. Age is accorded due respect. Old men are referred to as Amaokusuowel and old women as Amaokusuere. The leadership Cadre is made up of heads of the different household. Community leaders are selected on the criteria of wealth, leadership qualities and age. Although women play a subsidiary role in the social life of the communities within the BCA FDP area, they are very active economically. Political Organization EIA of Benisede Catchment Area FDP Phase 2 June, of 253

125 Chapter Six Two levels of political organization, the formal governmental and the local /traditional administration are operating in these communities. At the governmental level, Peretorugbene is in Ekeremor LGA in Bayelsa state while Ojobo belongs to Burutu LGA in Delta state. At the local/traditional administration level, three tiers of authority are involved. They include: (i) The traditional ruler and his chiefs, (ii) Community development committee, and (iii) The youth council. The Traditional ruler and his Chiefs are at the apex of political authority in these communities but effective political power actually lies in the hands of the members of executive of the community development committee (CDC) (popularly known as the community executive). A chairman who is invariably very charismatic heads this committee. Committee members are entrusted with the day to-day affairs of the community. All visitors are obliged to first of all confer with the chairman and other members of the executive before activity of any sort is carried out. Without the permission of the community executive, it is not possible for a contractor or a consultant to carry on any business related to oil exploitation in the area. The community executive reports to the traditional ruler and his chiefs. The third tier of Government/authority in the community is the youth council headed by a vocal president. The council obeys and accepts the decisions of the higher tiers of authority. They consult with the community executive and the traditional rulers in all matters in the community and are not permitted to act on any issue without due permission. Unlike the formal governmental level where the three tiers of authority are very effective, the youth restiveness that is common in these communities makes the traditional administration ineffective. Economics and Livelihood Attempt was made to compute earnings from different sources available to residents within the BCA FDP area. About 27% of residents within the BCA FDP EIA of Benisede Catchment Area FDP Phase 2 June, of 253

126 Chapter Six area earn over N2000 weekly from fishing while 42% earn less than N500. Over 30% of residents within the BCA FDP area earn less than N5000 from other sources while 33% earn between N1500 N2000 from other sources. Incomes claimed appear quite substantial by national standards or those of Bayelsa and Delta States where the settlements are situated. What is more, the communities are rural, a region usually notorious for its poverty especially in the developing countries. Significantly, the poor physical environment tends to lend support to the suspicion that the incomes may have been exaggerated. But the apparent wealth of the communities is counter balanced by the high costs of living. Costs of living are very high and are not reflected in the living standard. Consumer s goods including food items are at least twice as costly as in the mainland. Fuel costs are particularly high, a somewhat ironical development given the fact that the area is rich in petroleum. Because of the high fuel costs, transportation is very expensive. The high costs of living therefore results directly from the high costs of fuel as traders pass on their transportation expenses to consumers. A recurrent socio-economic problem that has since assumed a political dimension is the issue of unemployment. The exact extent is yet to be quantified but the problem is directly implicated in the societal turmoil in the Niger Delta region as unemployed people struggle to make out a living one way or the other. Quality of life Quality of life measures the amount and distribution of socio-economic variables such as electricity, pipe borne water supply system, access road, educational institutions, health facilities, housing type and a market for the exchange of farm and other products Electricity PERETORUGBERE AND OJOBO HAVE FUNCTIONAL ELECTRICITY SUPPLY AND THE POWER GENERATING SETS ARE SWITCHED ON ONLY AT NIGHT. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

127 Chapter Six Potable Water Portable water is not available in Peretorugbene and Ojobo. Even where monopump water project has been completed, they are not functional. People from these communities depend on water from rivers and creeks. Road and Transportation The construction of beachfront road in Ojobo was proceeding during the dry season field survey and was completed before the wet season field survey. The terrain in these communities makes road building/construction very expensive and difficult to undertake. Plate 11: Dugout canoes common means of transportation of goods and persons in the study area. The menace of floods is one of the greatest problems facing the settlements. Rise in water levels may lead to the total submergence of houses within the settlements. Hence adequate action has to be taken to solve the problem. Transportation between communities is tedious and expensive with the use of speedboats. The popular passport-19 ply the major communities to mainland towns EIA of Benisede Catchment Area FDP Phase 2 June, of 253

128 Chapter Six like Warri where traders buy their goods. For short journeys, dugout canoes (popularly known as hand-paddled canoe) are used and are usually very slow and precarious as faster boats and river turbulence can make it very risky. Housing Most houses within the BCA FDP area are built of reeds and thatch. Along the shoreline, the houses are built on stilts; though fairly durable, they are not physically attractive. Plate 12: A Typical Shoreline Settlement in the Study Area - Peretorugbene Few modern houses are also found in these communities and are concentrated in larger settlement and L.G.A. headquarters The primary and secondary schools that have all benefited from SPDC educational infrastructure development scheme are additional lifts to the physical decadence of these settlements. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

129 Chapter Six Education Education is one area in which the settlements have witnessed some development. There are a total of 18 primary and 8 secondary schools distributed almost evenly in the BCA FDP host communities as shown in Table There is however, the problem of shortage of teachers as all the schools (both primary and secondary) are understaffed. At present staffing level, the teacher-pupil ratios are 1: 177 and 1:52 for primary and secondary schools, respectively. School enrolment is skewed in favor of males at both primary and secondary levels. Boys make up 57.2 percent total enrolment in primary schools while girls constitute 42.2 percent of total enrolment at the secondary level. The level of physical development in the schools has been enhanced by the visibility of the schools. Even so, only a few staff quarters and sports facilities exist. The most notable of the latter is the sports complex at Agidiama consisting of facilities for soccer and lawn tennis. The facility was built by SPDC. The national teachers institute, Kaduna runs courses leading to the award of teacher s certificate in Peretorugbene, Tamogbene and Ojobo. This is part of the distant education scheme operated by the institute. Table 4.14: School Enrolment Statistics 2001 Settlement Primary Secondary Schools Enrolment Teachers Schools Enrolment Teacher Ojobo Peretorugbene e a Total EIA of Benisede Catchment Area FDP Phase 2 June, of 253

130 Chapter Six Sanitation and Waste Disposal There is no organized system of sanitation or waste disposal within the BCA FDP area. Domestic wastes are thrown about without order but generally behind or beside houses or even directly into the river. As houses are usually built without toilets, human waste is discharged directly into river from which water for drinking and domestic use is obtained. Domestic wastewater is merely thrown into the street or just by the house or even directly into river from which water for drinking and domestic use is obtained. All the settlements, without exception, are in very urgent need of modern sanitation and waste disposal systems. Jetties and shoreline protection Because all the settlements are riverine and liable to erosion, jetties and shore protection are very important infrastructure facilities. Unfortunately, not much attention has been paid to this aspect within the BCA FDP area, thus embarking or disembarking from canoes, boats or other vessels are often hazardous. Only Ojobo and Peretorugbene have concrete jetties. However, every community has one or more wooden jetties, which are all in various stages of disrepair. Health Studies The health status of an area is a function of the living standard of the people and the overall quality of the environment. The health status of the people of the project area can be summarized thus; (a) Nutitrition The diet of the local population is mainly locally caught fish (including shellfish). The average diet is therefore rich in protein, but usually lack vitamins and minerals owing to the high cost of their source food items. Cassava flour (garri), one of the staples in the area, is locally produced while rice, which is brought in from Sapele, Warri, Burutu and other inland communities, is expensive and in short supply. (b) Water Supply and Sanitation EIA of Benisede Catchment Area FDP Phase 2 June, of 253

131 Chapter Six Water for domestic purposes is drawn from hand-dug wells dug within the neighborhood, streams, rivers and surrounding creeks. Even the completed mono-pump water projects in the area are nonfunctional. Furthermore, domestic wastes (including sewage) are freely dumped along the banks of the creeks and rivers. These wastes become obvious at low tide, littering the coastline. At high tide, these contaminated water find their way into wells and other sources of drinking water, thereby transmitting pathogens into the water. This could be a major reason for the poor quality of life and health status of residents in the communities within the proposed project area, which is evident in the high cases of ailments like, cholera, typhoid and helminthic infections. (c) Housing Houses within the area are small, poorly ventilated and overcrowded with an average of about 5 to 7 persons per room. The overcrowding also aids the quick spread of communicable diseases. (d) Smoking and Use of Alcohol Smoking of cigarette was observed as characteristic habit of the people, mostly the youths. Alcohol consumption cut across age barriers, both adults and youths alike, indulged in the use of alcohol. (e) Health Facilities Health facilities were generally lacking in the area, even were health centers existed, they lacked equipment and drugs. However, there were some patent medicine stores in the communities. Most residents in the area depend on the patent medicine stores dealers doctors for medical attention while critical cases are taken to Yenagoa or Burutu. (f) Morbidity Patterns History and physical examination of the sampled population in the communities surveyed revealed certain morbidity characteristics. They include: Fever/frequent headache Blurred vision EIA of Benisede Catchment Area FDP Phase 2 June, of 253

132 Chapter Six Diarrhea and vomiting Skin rashes Marked weight loss Cough and Catarrh Sexually transmitted diseases (not HIV) (g) Mortality Patterns From interviews with the sampled population and records from health centers, mortality rates were high in the children and women (mostly during child delivery) than in men. This could be attributed to the inability of the traditional birth attendants to handle complications during labour, poor sanitation and effects of disease vectors like mosquitoes, etc. Health Risk Assessment Various hazards associated with the project are summarized in table The purpose of this matrix is to summarize in a birds s eye view the different existing hazards to health within the community, determine the levels to which the community members are exposed to these hazards and their sensitivities to them. Levels of exposure have been arrived at through questionnaire administration, participant observation and review of the relevant literature. Unless certain epidemiologic conditions relating to agent, host and environment are met, a health hazard may not necessarily lead to a disease, illness or health condition. Vulnerability scale (1-10) in Table 4.15, therefore, represents our assessment of the levels of interplay of these factors within the respective communities to result in susceptibility to the particular disease condition. Table 4.15: Health Risk Exposure Matrix (Health Sensitivities) Health hazard Risk to Health Current Levels of Exposure within Communities Sensitivity/Vulnerability Index (Scale 1-10) BIO-PHYSICAL EIA of Benisede Catchment Area FDP Phase 2 June, of 253

133 Chapter Six ENVIRONMENT Poor air quality met etc Respiratory diseases Moderate 7 High noise levels Hearing impairment Moderate 7 tolerance shift insomnia. Biotic factors Wild/venomous animals Disease Vector Fatalities, injury (from snake bites, wild animals) Moderate High 7 9 Abiotic Factors (Climate conditions) LIFE STYLE Alcohol and Drugs & Substance Abuse Disease transmission. Weather related maladies, vector epidemiology High 8 Organ damage to liver, lungs etc, impaired mental health tendency to crime and violence Moderate 4 STIs Moderate 7 Exposure to casual / commercial sex Unprotected sex STIs. HIV/AIDS Moderate 8 Cultural practices Female Gental Low 3 mutilation Recreation/stress Hypertension, Very low 6 management coronary problems Waste disposal and Communicable High 9 management diseases SOCIAL ISSUES Inequality Violence Moderate 4 Insufficiency of Infrastructure Poor health preventive and management interventions, insecurity, poor High 7 Poverty/Personal income levels communication Variety of diseases and maladies creating vicious cycle of disease and poverty High 7 Level of crime Injury fatality Low 4 Level of Violence Injury fatality Moderate 7 Level of Education Lake of awareness on appropriate preventive and health management Low to Modrate 4 EIA of Benisede Catchment Area FDP Phase 2 June, of 253

134 Chapter Six OCCUPATIONAL HAZARDS Fishing Activity (Paddling neting) Water Transport (paddling) Fish Smoking/Processing OTHERS practices Unguinal hernias Moderate 6 Unguinal hernias Moderate 5 Respiratory disorders, eye problems (conjunctivitis) High in vulnerable population (fish processing womenfolk) 7 POTABLE WATER INSUFFICIENCY MALNUTRITION/FOOD SECURITY HOUSING AND LIVING ENVIRONMENT DEMOGRAPHIC PROFILE TRAUMA (INJURIES FROM ACCIDENTS, BOAT MISHAPS ETC) Water-borne diseases (cholera, typhoid etc.) Nutritional maladies in vulnerable population (women/children) Upper respiratory tract infections. Diseases transmission, risk of fire More youthful population liable to high crime. Violence and STI levels Morbidity temporary/permanent death Very High 6 Moderate 4 Very high due 6 to overcrowding and practice of fish smoking within habitation Moderate 6 Moderate 6 Perception of the Project EIA of Benisede Catchment Area FDP Phase 2 June, of 253

135 Chapter Six The respondent groups stated that the beneficial aspects of BCA project was only in the area of employment (mainly as unskilled labour) and some welfare improvement programmes instituted in the host communities. Perceived adverse impacts of the project in the area include: 1. Increased gas flaring from the flow stations with its attendant ecological, human health and socio-environmental impacts. 2. Loss of wildlife in the area due to continuous lighting (especially at night time) from the flare stalks; 3. Reduction in games and hunting activities, a major source of household income in the area; 4. Excessive heat flux in the area resulting from the gas flares; 5. Oil spillage from manifold, flow stations, and obsolete equipment (pipeline), which usually destroys farmland, swamps (fishing grounds) and generally results in the loss of biodiversity in the area 7. Increased ocular and dermal ailments in the area, especially among children and the elderly. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

136 Chapter Six CHAPTER FIVE 5.0 CONSULTATION 5.1 General This chapter presents the details of Consultations undertaken for the proposed Benisede Catchment Area (BCA) Field Development Plan (FDP). It has been recognized in Shell Petroleum Development Company of Nigeria Limited (SPDC) that apart from being a regulatory requirement, consultation is part of good business practice. The primary objectives of effective consultation in the Benisede Catchment Area (BCA) Field Development Plan (FDP) are to: Meet statutory requirement, Identify stakeholders for the Benisede Catchment Area (BCA) Field Development Plan (FDP), Notify the relevant stakeholders about the Benisede Catchment Area (BCA) Field Development Plan (FDP), Explain to both Government and host communities the proposed project activities/operations and to ensure exchange of information that will facilitate good working relations, and Identify issues and concerns of the residents at an early stage to avoid unnecessary public opposition of the Benisede Catchment Area (BCA) Field Development Plan (FDP). 5.2 Consultation for the BCA FDP project Public consultation process in relation to the Benisede Catchment Area (BCA) Field Development Project was implemented by two agents. These are: (a) The proponent, SPDC and (b) The EIA/ SIA/HIA consultants Consultations by the Proponent In SPDC, consultation process is on-going and will be implemented throughout the life cycle of the project. For the Benisede Catchment Area (BCA) Field Development Project, SPDC has consulted with the regulators and the host communities. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

137 Chapter Six All the relevant Governmental and non-governmental organizations, agencies, and communities have been and will continue to be consulted by SPDC as the Benisede Catchment Area (BCA) Field Development Project progresses in line with statutory requirements and SPDC policy Field Consultations by EIA/ SIA/HIA Consultants Field consultations by EIA/ SIA/HIA consultants for the Benisede Catchment Area (BCA) Field Development Project were carried out by administering questionnaires and through interviews. (See questionnaires in Appendix V) 5.3 Identified Stakeholders for the BCA FDP Apart from the proponent and all her operators, the underlisted stakeholders of the Benisede Catchment Area (BCA) Field Development Project have been identified. They are: The Regulators (Federal Ministry of Environment, Department of Petroleum Resources, Ministries of Environment/Environmental Protection Agency or Body in Bayelsa and Delta States, etc), Host Communities of the Benisede Catchment Area (BCA) Field Development Project 5.4 Consultation with Regulators for the BCA FDP As part of the consultation with regulators for the BCA FDP project, a detailed project proposal/terms of reference (TOR) has been submitted to Federal Ministry of Environment and Department of Petroleum Resources (see Appendix V). This process, which, registers the proponent s intention with the regulators to embark on the proposed BCA FDP project was followed by Site Verification visits to ensure that the consultation is done prior to the commencement of the project. 5.5 Consultation with Host Communities for the BCA FDP Scoping workshop report for the project and Minutes of meetings are provided in Appendix V. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

138 Chapter Six 5.6 Community Concerns about the BCA FDP Some of the concerns and expectation of the residents of BCA FDP area are listed below. Employment of the indigenes into the oil companies Provision of basic amenities like pipe-borne water and electricity Provision of Schools and award of scholarships to indigenes Provision of micro-credit facilities to boost economic activities in the communities Construction of good road network to enhance evacuation of agricultural produce and fish products to the market in town Provision of marine vessels to enhance local transportation within the riverine communities Construction of Landing jetties and shoreline protection facilities to prevent shoreline erosion. 5.7 Community Assistance/Community Development Projects The BCA communities have all benefited from SPDC Community Assistance/Community Development (CA/CD) programmes. A good number of social infrastructural facilities were provided to the communities such as: Post primary school and University Scholarship to deserving students annually. In anticipation of the proposed Field development projects, the Southern Swamp AGG, Pipeline and Flowline construction work, etc., SPDC in 2001 signed a 5-year development plan Memorandum Of Understanding (MOU) with Ojobo and Peretorugbene communities respectively. In the signed MOUs is a plan for interdependency electricity project for the two communities. It is hoped that when these projects are completed, disruption to SPDC operations in the area will be minimised. Similar MOUs are being developed for the Amabulou Federated communities. There is also a development plan already put in place, as well as annual CD plan for some of the pipeline and gateway communities. SPDC Community Assistance (CA)/Community Development (CD) projects and their current status in the BCA FDP project Area are presented in Chapter 8 (Tables 8.4 and 8.5). EIA of Benisede Catchment Area FDP Phase 2 June, of 253

139 Chapter Six CHAPTER SIX 6.0 POTENTIAL IMPACT ASSESSMENT 6.1 General Impact assessment is required for all major public and private projects that might significantly affect the quality of the environment. It is intended to provide reasoned predictions of the possible consequences of policy decisions and thus, to permit wiser choices among alternative courses of action. In pursuance of its policy on the environment and in compliance with relevant national and international laws and conventions, acceptable industry standards, SPDC has embarked on this impact assessment prior to the commencement of the project. The study is intended to predict, identify, interpret and communicate the impacts of the various phases of the project on the environment. This Chapter however evaluates the potential impacts of the various project activities of the proposed Benisede Catchment Area Field Development Plan project on the environment. The stepwise approach adapted for the assessment is illustrated in Fig Principles of Impact Prediction and Evaluation Whatever the impact and whatever specific technique is used to analyse it, prediction and evaluation should be based on a sound methodological framework, which covers; The overall prediction and evaluation process Choice of prediction technique Criteria for evaluating significance The design of mitigation measures Indirect impacts, long range impacts and uncertainty EIA of Benisede Catchment Area FDP Phase 2 June, of 253

140 Chapter Six Identification of Project Activities and Process [using knowledge of project/technic al description] Assessment of Interaction of Project Activities with environmental components [using opinion of experts and stakeholders and design assumptions.] Evaluation of Impact Significance Comparative analysis Evaluation of importance of ecosystem. Ecosystem vulnerability juxtaposed with project activities. Weigh Impacts Existing Regulations. Significant Against DPR FMENV International Conventions. Natural concentrations EIA of Benisede Catchment Area FDP Phase 2 June, of 253

141 Chapter Six 6.3 Impact Assessment Methodology There are several approaches and techniques developed for evaluating potential impacts of any project on the environment. Some of which were developed in the early 1970s and lean heavily upon approaches used in other spheres of environmental management (Wathern, 1986). The Overlays techniques (McHarg, 1968); Leopold matrix (Leopold et al., 1971); Battelle Environmental Evaluation System (Dee et al., 1973) and Peterson Matrix (Peterson et al., 1974) are among the most widely used methods employed for impact assessment. The overlay technique The overlay technique uses a series of transparencies to identify, predict, assign relative significance to, and communicates impacts in a geographical area. In this method, the study area is sub-divided into convenient geographical units, based on uniformly spaced grid points, topographic features or differing land uses. Within each unit, the assessor collects information on environmental factors, through aerial photography, topography, land inventory maps, field observations, public meetings and discussions. The concerns are assembled into a set of factors, and used to draw a regional map. By a series of overlays the land-use suitability, action compatibility, and engineering feasibility are evaluated visually, in order that the best combination may be identified. Leopold Matrix Leopold et al (1971) were the first to suggest the use of a matrix method for impact assessment. This method is useful as it reflects the fact that impacts result from interaction of development activities and the environment. Thus, Leopold Matrix is a comprehensive checklist designed for the assessment of impacts associated with almost any type of construction project. One hundred possible project actions are listed on one axis, eighty-eight human and natural environmental elements on the other. The Leopold matrix is also used to present the results of an appraisal. Numbers representing magnitude and significance, expressed on a 10-point scale, are included in each cell indicating where a likely impact is anticipated. Positive and negative impacts are identified with + or - sign, respectively. Battelle Environmental Evaluation System EIA of Benisede Catchment Area FDP Phase 2 June, of 253

142 Chapter Six The Battelle Environmental Evaluation system involves the separation of human concerns into four categories namely, ecology, physical/chemical, aesthetics and socio-economics. The method translates the state of individual environmental parameters into arbitrary, environmental quality indices all expressed in the same scale. For each component, the Battelle system develops an index of environmental quality, normalised to a scale ranging from 0 to 1, using a value-function method. Each impact indicator is given as the difference in environmental quality between the states with and those without actions. Environmental quality scores are multiplied by the appropriate weightings and added to give a total score of environmental quality for each option under consideration. Peterson Matrix Peterson Matrix is a modified version of Leopold matrix, adopted for the screening and scoping exercise of this project. This matrix relies directly on the multiplication properties of matrices. An ordinal scale is used to evaluate individual impacts by a team of assessors, and separate matrix layers are produced for physical and human impacts. The matrices are also multiplied to find the effect of the casual elements on human environment while the resulting product is weighed according to the significance of the human impact Screening and Scoping of the Potential Impacts It has become necessary to undertake an early and open process for determining the scope of issues to be addressed and for identifying the significant issues relating to a proposed action. It is important that the effective screening of actions takes place in all environmental assessment systems. Without it, unnecessarily large numbers of actions would be assessed and some actions with significant adverse impacts may be overlooked. The determination of whether or not an environmental assessment is to be prepared for a particular action should hinge upon the likely significance of its environmental impacts. Lee, (2000), identified two broad approaches to the identification of such action and they include: The compilation of list of actions, accompanying thresholds and criteria (which may include locational characteristics) to help in determining which actions should be assessed, and EIA of Benisede Catchment Area FDP Phase 2 June, of 253

143 Chapter Six The establishment of a procedure (which may include the preparation of a preliminary or intermediate environmental assessment report) for the case by case (discretionary) determination of which actions should be assessed. To undertake this process, an assessment of the environmental impacts of action should be made. For this project, the likely significant potential impacts of the proposed development project on the swamp ecosystem of Benisede Catchment Area fields are derived from the following: Knowledge of the project activities, equipment types and layout of the project facilities; The status of the baseline of the environment; Findings of other EIA studies on similar projects; Experience on similar projects and Series of expert group discussions and meetings. The criteria applied for predicting the impacts for this project on the swamp environment were: Magnitude -- probable severity. Prevalence -- likely extent of the impact. Duration and frequency -- intermittent, short term, long term. Risk -- probability of serious effects. Importance -- value attached to the undisturbed project environment. The screening of the project activities indicate that construction of wells, flowstation, transportation of materials to site during construction phase, presence of infrastructure during operational phase pose a threat to the biotic and abiotic components. Most of the adverse effect will come from construction phase involving the drilling of wells, dredging, flowstation upgrade, and laying of flowlines. These impacts are expected to be short-term and shall cease with the completion of the construction phase. Impacts from operational phase are expected to be long-term. The social components are expected to have beneficial impacts like the recruitment of labour force, which will increase income and inject a sizeable amount of cash into the Nigerian economy. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

144 Chapter Six The main environmental components that shall be significantly impacted are water quality, ecology, fisheries, wildlife fauna, health and safety of host communities and workers. The impact indicators are defined and adopted so as to identify potential environmental impacts. Impact indicators are the easily observable environmental components, which readily indicate changes. The impact indicators used for this study are presented in Table 6.1 TABLE 6.1 ENVIRONMENTAL COMPONENTS AND POTENTIAL IMPACT INDICATORS Environmental components Climate Air Quality Soil Surface water Characteristics Impact Indicators Temperature, Rainfall, Relative Humidity Particulate, NO x, SO x, CO 2, CO, VOC Soil type and structure, physico-chemical and microbiological characteristic Dissolved and suspended Solids; Turbidity, Euthrophication and Toxicity Ecology / Hydrobiology Sediment Characteristics Species diversity, Abundance, Productivity, Yield. ph, Heavy metal concentration, The scoping of potential impacts involves identifications of interactions between project activities and environmental impact indicators. This stage of the impact assessment process simply qualifies impacts as beneficial or as adverse. Ranking of the potential impacts at this stage is done on a scale of 1 to 5 and the interpretations are as follows: 1 = Very low impact (insignificant) EIA of Benisede Catchment Area FDP Phase 2 June, of 253

145 Chapter Six 2 = Low impact (insignificant) 3 = Moderate impact (significant) 4 = High impact (significant) 5 = Very high impact (significant) The ranking, relative to recovery period was as follow: Transient Short term Medium-term Long term Very long/permanent A few hours to some days 6 months, 6 12 months >12 months 5 years A checklist of key project activities and description of the potential and associated impacts identified for the various activities is presented in Table 6.2. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

146 Chapter Six Table 6.2: Potential and Associated Impact Identification Checklist PROJECT ACTIVITY Mobilization and other logistic demands Site Preparation and Drilling Dredging Unintentional discharges Employment of locals as skilled and/or unskilled labour. GENERAL DESCRIPTION OF IMPACTS NATURE OF IMPACTS Adverse Beneficial Short-term Long-term Interference with other public and private water transport activities and alternative uses of the mob. / demob. route(s) and drilling sites. X X Physical disturbance of Bomadi and Brass Creeks by the X X flowstation anchors and chains. Emission of atmospheric pollutants from exhausts. X X Reduction in aesthetic and recreational value of drilling X X sites. Pollution of surface water by anti-fouling chemicals used to coat metal surface to discourage growth of algae and corrosion. X X Increased turbidity of surface water, dislodging of aquatic X X organisms and disruption of fish spawning. Increase in biological and chemical toxicity of surface water from discharged chemicals, wastes and materials X X including spent mud, oily wastewater, sewage, cooling water and additives etc. Pollution of surface water from spilled hydrocarbons that may occur as a result of sabotage, well blow-outs, flowline ruptures, etc. X X Destruction of benthic flora and fauna by unintentional dumping of drilling mud and cuttings. X X X X Increased income and livelihood Localised increase in baseline concentrations of surface Discharge of drill cuttings, sewage, other wastes, gaseous emission and noise water physico-chemical parameters from routine discharge of drill cuttings, chemicals, treated sewage, deck drainage, etc. Localised dumping of drilling mud and cuttings in the Bomadi and Brass Creeks. X X X X EIA of Benisede Catchment Area FDP Phase 2 June, of 253

147 Chapter Six Operations PROJECT ACTIVITY GENERAL DESCRIPTION OF IMPACTS Localised increase in ambient concentrations of air pollutants from the exhausts of fuel combustion engines NATURE OF IMPACTS Adverse Beneficial Short-term Long-term and well testing flaring. X X Possible collision of boats during operation. Noise (on-site) from the use of operations engines and motors. X X X X Increased national revenue from oil and gas exploitation X X Employment of locals and consequent increase in business activities in the area X X Oil spills Community Development Programmes X X Oiling of surface water. This will reduce light penetration and thus overall productivity of the ecosystem. X X Oiling of surface water can also reduce dissolved oxygen levels and cause oxygen starvation and death of aquatic organisms. Spilled oil may emulsify and eventually dissolve into surface water to increase its toxicity. This may lead to the death of the less resistant/adaptable aquatic organisms and X X dominance of the more resistance ones. X X Decommissioning and abandonment Collision of boats with abandoned wellhead structures. X X Permanent obstruction of Creek-bottom with permanent structures such as the wellhead structures. X X Hydrocarbon leak from abandoned wellhead and flowlines. X X EIA of Benisede Catchment Area FDP Phase 2 June, of 253

148 Chapter Six 6.5 Potential Impact Evaluation The purpose for this evaluation is to assign relative significance to the predicted impacts associated with this project and to also determine the priority order in which the potential impacts are to be avoided or mitigated. This involves the computation of the potential impact of the project activities on the recipient environment. The first step is to determine the magnitude of impact and thereafter evaluate the importance of the impact relative to its ecological and social values. The evaluation of the degree of alteration to natural conditions due to the project activities were carried out using a modified Leopold and Peterson matrices that permits scaling and direct transformation of impact magnitude and importance into potential impact significance (Peterson et al., 1974); (See Table 6.3). The significance of impacts are linked to the following elements; Effect of project action on wildlife Ecosystem sensitivity, biodiversity and carrying capacity Viability of local species population Rare and endangered species Duration Demand on transport Recreational values of the prospect In this method, project activities are assigned to columns, while environmental components and characteristics are indicated in rows in the matrices. Then the project activities are interacted with the environmental components and characteristics using mathematically weighted values for each activity with respect to the environmental components and characteristics. The mathematical weighting was done based on the magnitude and importance of potential impacts of the project activity on the environment. Where possible, quantification of impacts has been undertaken. In some cases, systems of weighting together the quantitative scoring of rankings of various effects have been adopted, but there is no general consensus as to the relative values. The value assigned to each cell in the matrices is in the form x (y) : where x denotes the magnitude and y the importance of the impact. Positive (+) and negative (-) signs were used to represent beneficial and adverse impacts respectively. The effect of any particular activity across all environmental components and EIA of Benisede Catchment Area FDP Phase 2 June, of 253

149 Chapter Six characteristics are assigned columns, while the potential impacts of all project activities on a particular environmental component or characteristic are assigned to rows. A quantitative evaluation of the impacts of the BCA FDP drilling project on the environment are shown in Table 6.3. Summary of Potential Impact Evaluation The evaluation of the impact of the Benisede Catchment Area FDP project activities on the various environmental components is presented in Table 6.3. The proposed project activities, which could adversely impact the environment of the project area, are, transportation of equipment and materials, construction, (flowline laying, trenching, backfilling, hydrotesting, dredging, drilling, etc.), and abandonment. The adverse environmental impacts, which are likely to occur mostly at the construction phase (site preparation/drilling) of the BCA FDP project, shall be shortterm. Consequently, these adverse impacts will be localized and transient. However, mitigation measures have been proffered, to eliminate or reduce these impacts to tolerable levels. Overall, the beneficial impact from the BCA FDP project shall be long-term. These beneficial impacts will result from increased business activities in the area, employment for skilled and unskilled labourers and community development activities. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

150 Chapter Six Table 6.3: Impact Evaluation Matrix for BCA FDP Environmental Component (x) Project Activities Aggregate Rating of Ecological Components (y) Site Mobilization/ other logistic needs Construction and Installation/Flowline laying Dredging Drilling Wastes disposal Operations / Maintenance Materials Transport Accidental spill & Leaks Gaseous Emission/Flares Demobilization Air Quality Particulates Acid gases (SO x, NO x, NH 3 ) CO x VOC Surface water Quality Turbidity and solids Temperature Oil and Grease Biochemical Parameters Groundwater Quality Turbidity and solids Oil and Grease Biochemical Parameters Aquatic Ecology Diversity & abundance Productivity Catch and Yield Vegetation/ Terrestrial Ecology Diversity & abundance Forest Resources Habitat Productivity Soils/Landuse Soil fertility / Productivity Soil Erosion Land take Sediment Characteristics Physico-chemistry Productivity Noise/Vibration On-site Off-site Detailed Description of Potential Impacts EIA of Benisede Catchment Area FDP Phase 2 June, of 253

151 Chapter Six Rig Mobilisation The drilling campaign will involve several movements in the course of the drilling project. There shall also be the need for spread mooring with chain, standard wire cable and anchor for each leg of the rig. These operations and activities are likely to have the following impacts: Discharges and emissions Creek disturbance and interference due to anchoring and movement; Fisheries interaction; and Boat navigation interaction. The process of mobilisation and movement of construction materials to site shall exert stress on the creeks resulting in the suspension of sediments. This could lead to destruction of habitats/communities of benthic organisms. Flowstation positioning shall also cause disturbance to Creek-bed through increase in suspended solids, smothering/burial of fauna. However, this impact is considered insignificant, as recovery time is usually short. The physical presence of the wellheads, flowstation and other facilities may be an obstacle to fishing and navigational routes within the area. Nevertheless, this impact is not significant because of the relatively small area these facilities will occupy Drilling The primary sources of impact associated with the drilling operations are related to waste disposal. Thus in the course of this project, the following category of liquid effluent, and other potential release may affect the water quality of the block. These includes: Drilling fluid and cuttings; Grey water from house-showers or galley Black water from sewage system Accidental releases (such as diesel fuel, crude oil) Drilling fluid and cuttings; EIA of Benisede Catchment Area FDP Phase 2 June, of 253

152 Chapter Six The main activities, which may result in environmental impacts, include those associated with drilling mud and the disposal of drilling cuttings. SPDC consider the need for clean and unpolluted environment in their operational areas and therefore propose to use water based mud (WBM) and pseudo oil based mud (POBM) in their proposed drilling programmes. WBM are widely viewed by the industry and regulators as being sufficiently non-toxic as to have special disposal requirements. According to the UNEP (1985) WBM and POBM discharges are not especially toxic, being either biochemically inert or non-toxic derivatives of natural product. The primary causes of drilling impacts are from smothering of the sediment by discharged materials, which includes the drilling rock cuttings and the drilling mud. While the drilling cuttings cause physical changes in the sediment characteristics, it is the drilling mud, which causes significant chemical changes, which may have longerterm effects. The overall impacts are related to the total tonnage of discharges, their distribution across the seabed and the chemical characteristics of the drilling mud Sewage and Sanitary Wastes This includes all sanitary waste and grey-water, that is water from showers sinks, garbage disposal, etc. This waste will be treated in the sanitary sewage treatment unit before disposal. This is particularly important since the well construction phase of the project will require about 100 men on site Accidental Oil Spill Accidental oil spills could have serious economic impact on coastal activities and direct health impact on the host communities. In most cases such damage is temporary and is caused primarily by the physical properties of oil creating nuisance and hazardous conditions. The impact on aquatic life is compounded by toxicity and tainting effects resulting from the chemical composition of oil, as well as by the diversity and variability of biological systems and their sensitivity to oil pollution. The effects of oil spills on fish larvae are even more pronounced when dispersants are used. In addition, crude oil contamination of the water from which phytoplankton derive nutrients will adversely affect the rate of primary production Impact due to Dredging Dredging activities during the proposed project will result in the following impacts: EIA of Benisede Catchment Area FDP Phase 2 June, of 253

153 Chapter Six Changes in water quality viz higher turbidity, reduced light penetration, stress on photosynthetic algae including other light sensitive organisms. Noise of dredging operations. Offensive smell from dredged spoils. Loss of biodiversity. Vibrations. Prevention of fish migrating to spawning grounds. Destruction of spawning grounds by the removal of habits. Possible release of locked up nutrients by the agitation and overflow of dredged spoil. Possibility of subsoil failure. Possible depletion of local fish communities. River bank draw down i.e. movement of materials riverwards due to removal of sediments Impact due to Flowline Installation: Flowlines will be laid across the Creek-bed resulting in localised bed disturbance. Such disturbances may take the form of loss of benthic organisms through smothering or burial, interference with fishing activities, navigational impacts, suspended solids, anchor damage to the creek-bed, etc. The precise width of sediment disruption is unclear and varies according to the type of substrate and depth of water Gaseous Emissions Atmospheric or gaseous emissions anticipated during the project will emanate from fuel powered boats, electrical generators, vented gases (during testing), flared gases from well testing/well clean-up, helicopter, and fugitive emissions, e.g., leaks from components such as valves and connectors. The emissions are dependent upon the fuel use of boats, generators, etc Impact on Fishing Commercial Fishing: EIA of Benisede Catchment Area FDP Phase 2 June, of 253

154 Chapter Six The presence of utility boats on the creeks during transportation of equipment and materials would obstruct the movement of fishing boats. In addition, the high turbidity of the surface waters that is likely to result during drilling and other construction activities would reduce dissolved oxygen, which is crucial for fish yield. This is likely to have limited temporary interference with commercial fishing activities in the area. There may also be limited temporary interference from periodic visits to the flowstation by supply vessels Impact due to Well blow-out: A blow out is one potential impact of drilling operations that must certainly be avoided because such an occurrence, which results in the sudden release of pressure, could be devastating. Well blowouts or explosions are associated with geological formations that are characterised by abnormal formation pressure. Oil, saline water, and volatile organic compounds (VOC) could be emitted into the atmosphere. The subsequent explosion could emit dangerous gases into the air, as well as oil and chemicals into the swamp environment, which could also contaminate soil and sediments Beneficial impacts The execution of the field development plan activities will provide employment opportunities for unemployed Nigerians. The number of persons to be employed shall however, depend on the work force needed and the proportion of the work activities. Provision of employment during the project execution will have additional benefit augmenting household incomes and thus improving living standards. Moreover, the Benisede Catchment Area FDP project is expected to pave way for the further development of the oil resources in the Southern Swamp Production Area. This will bring about associated financial benefits to SPDC and Nigeria. 6.7 RISK ASSESSMENT Risk assessment according to Wathern (1986) stresses formal quantification of probability and uncertainty. Thus a study that provides quantitative measures of risk levels, where risk refers to the possibility of uncertain, adverse consequences, most fundamental estimates of possible health and other consequences. A risk assessment EIA of Benisede Catchment Area FDP Phase 2 June, of 253

155 Chapter Six typically includes a determination of the types of hazard posed, together with estimates of probability of their occurrence. It also includes the population at risk of exposure and the ensuing adverse consequences (Conservation Foundation 1984) Assessment of Hazards Assessment of HSE risk associated with identified hazards in SSA operations and activities are carried out regularly in line with corporate procedure. All hazards, effects and aspects identified in the HEMP process shall be ranked in terms of risk. For the qualitative portrayal of risk and screening criteria for potential incidents and chronic effects, the concept of the risk matrix (Table 6.4) shall be used. The assessments (hazard register and aspect tables/registers) are updated at specified intervals defined in the HSE Case. The assessments shall be reviewed when circumstances change as part of the change control procedure. Table 6.4: SPDC HSE Risk Matrix CONSEQUENCE Severity People Assets Environment Reputation 0 No injury No damage No effect No impact PROBABILITY A B C D E Never Incident Incident Happens Happens heard of has has several several incident in occurred in occurred in times per times per industry oil industry SPDC year in year in SPDC District 1 Slight Injury 2 Minor Injury Slight damage Minor damage Slight effect Slight impact Minor effect Limited impact Low Risk 3 Major Injury 4 Single Fatality 5 Multiple Fatalities Localised damage Major damage Extensive damage Localised effect Considerabl e impact Major effect National impact Massive effect Internationa l impact Medium Risk High Risk Project Risk Management In order to continuously address the risks associated with this project a risk register was set up and routinely updated. Risk events affecting all aspects of the project were EIA of Benisede Catchment Area FDP Phase 2 June, of 253

156 Chapter Six identified i.e., wells, reservoir, facilities, communities, commerce, organisation and politics. It is recommended that the register is kept alive through out the project implementation phase. The BCA FDP Project shall be carried out within the framework of SPDC Corporate policy. The Hazards and Effects Management Process (HEMP) activities will ensure and demonstrate the reduction of risks to ALARP levels Health, Safety and Environmental Management System in BCA. The SPDC HSE Policy requires a systematic approach to HSE management designed to ensure compliance with the law and to achieve continuous performance improvement in the Benisede Catchment Area. The HSE management system as operated in Benisede Catchment Area facilitates the management of HSE hazards and effects associated with its business. This includes the organisational structure, planning activities, responsibilities, standards, documentation and resources for developing, implementing, achieving, reviewing and maintaining the company's HSE Policy and meeting it's stated objectives. The system concentrates on critical activities and ensures that they are properly controlled and that measurements are made and reported so as to enable monitoring of overall performance and identification of areas for improvement. This management system provides a structured process for the achievement of continual improvement. The Benisede team is currently working and improving the system to bring about improvement in HSE performance. This also includes for behaviour and attitudinal change to support compliance with the system. In line with the EP Position on Global Environment Standards, the Benisede Catchment Area operations and facilities have implemented an HSE MS (documented HSE Case) and the environmental component of the HSE MS has been certified to ISO standard. Other environmental targets set by the Shell Group as contained in the Group Minimum Environmental Expectations (MEE) are being implemented in the Benisede Catchment Area. However, two of the MEE items, Elimination of routine gas flaring EIA of Benisede Catchment Area FDP Phase 2 June, of 253

157 Chapter Six and Elimination of Hard CFC with target dates of 2008 and 2005 respectively, are pending for the field. Currently H, S and E in Benisede Catchment Area operations is managed within an integrated HSE Management System, but in the longer term, it is expected that Management Systems, which encompass all aspects of the business, will become the norm. 6.8 Modelling Air Quality Modelling Meteorological Conditions The meteorological conditions used for this study are based on actual field data and available historical data for the project area. Ambient air conditions most conducive to primary impacts are: Mixing height of which is low and persistent Wind direction that is persistent towards sensitive receptors (southwesterly in this case) Wind speed which is calm to low Slightly unstable stability (class C) Emissions The summary of daily emissions from the proposed flowstation per day is as indicated in the Table 6.5. Table 6.5: Summary of emissions from the proposed flowstation Emissions (Tonnes/day) Sources CO 2 CO NO 2 N 2 O SO 2 CH 4 VOC Flaring Fugitives & Miscellaneous Internal Combustion EIA of Benisede Catchment Area FDP Phase 2 June, of 253

158 Chapter Six Engines Total Flare Emission Dispersion Model The dispersion of air-borne effluent from the proposed flowstation flare points in the Benisede project was predicted using SCREEN Model - Version 1.1. This model was applied in performing single source, short-term gaseous effluent dispersion including maximum ground-level concentrations and the distance to the maximum ground level concentrations, incorporating the effect of downwash on the maximum concentrations for both the near wake and far wake regions. The Flare Emission Dispersion Model simulates events of a prolonged shot-down of the CPF, which will entail the flaring of gases locally, via 16inch vertical or horizontal flare stacks at the Flowstation. The modelling calculation was based on engineering/design specifications, hydrocarbon gas composition and meteorological characteristics of the area. These include basic flare stack diameter of m (16 inches), wind speed of 10ms -1, radiation level of 3.15 KW/m 2, for the stack and maximum predicted flow of 16.5mmscfd and a Rich Gas composition of molecular weight of was used. The effective flare stack height of 30.0m was applied for the vertical flare stacks The simulation result indicates that the final stable plume heights of 33.1m for the flare stack and would occur at a distance of 1500 to 2000m from the stack. From the simulation (also presented graphically in Figure 6.2, it can be inferred that the maximum concentration of flare emissions from the stack would be observed 200 and 500m from the flare. The maximum observable concentration of acidic gases from the flare stack in the prevailing wind direction is mg/m 3. This result implies that monitoring stations should be established 200 to 500m from the flare stack along the prevailing wind direction. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

159 Chapter Six EIA of Benisede Catchment Area FDP Phase 2 June, of 253

160 Chapter Six EIA of Benisede Catchment Area FDP Phase 2 June, of 253

161

162 Chapter Six Conc. (mq/m3) Distance from Flare (x 100m) Fig 6.2 : Benisede Catchment Area Flare Emission Dispersion Model EIA of Benisede Catchment Area FDP Phase 2 June, of 253

163 Chapter Seven The estimated maximum concentrations for 1-hour, 3-hour, 8-hour and 24-hour averaging time for the proposed flare stack in the project area is as shown in the table below. Table 6.6: Maximum Concentrations for Selected Periods (hours) Period (hrs) Concentration 1 hour 680.9mg/m 3 3 hour 612.8mg/m 3 8 hour 476.6mg/m 3 24 hour 272.4mg/m 3 The above results imply that the predicted hourly maximum emission concentrations from the proposed project area flare stack would be within FMENV regulatory limits of mg/m 3 for acid gases from stationary sources (FEPA, 1991). This is mainly due to SPDC s choice for appropriate design specifications and stack height of 30m which comply with good engineering practice (GEP) with no downwash effects. The emission from the project area flare stack will not have adverse significant potential environmental impacts on the vegetation, soil, water and air quality of the area as the flaring will be sparing and intermittent Surface Water Quality Modelling Methodology The depths across Bomadi and Brass creeks, and some creeklets at the designated sampling stations were determined using a Sounder. The width of the creeks/creeklets was measured and plotted directly on the topographical (Base) map of the Project Area showing Creeks and Creeklets and existing/planned facilities Input Data The flow rate (current), width and depths across the creeks/creeklets at each of the sampling stations in the proposed project area is shown in Table 6.7. The flow rate, width, depths, aquatic temperatures (generally very high, ranging from 21.8 to 33.4 o C, air temperature, water transparency (generally low with an average depth ranging from 40.7 to 46 cm), turbidity (high ranging from 2.1 to 56.0 NTU). The surface water flow EIA of Benisede Catchment Area FDP Phase 2 June, of 253

164 Chapter Seven rates ranged from 4.45 to 23.65cm/sec while the depth and width of the rivers and creeks range from and m respectively. Table 6.7: Flow rate (current), Width and Depths across Creeks and Creeklets Sampling station Width (m) Depths (m) Flow rate (cm/sec) Edge Middle Edge W W W W W W W W W W W W Results Oil slick on water bodies in the study areas will form patches of thick oil and sheen in the downwind portion of the slick. During the spreading and transport of the slick, spilled oil will be subjected to further emulsification, evaporation to the atmosphere, dispersion and sedimentation into the waters (Fig. 6.3). Slick will therefore spread and grow in area, but its thickness will decrease. The activities will be enhanced due to the corresponding high water and air temperatures in the area. Over a 10 0 C temperature range, the density of waters in the study areas will change by 0.25% whereas oil density will change by 0.5. Therefore oil which barely floats during the day and may submerge (sedimentation) as the temperature falls at night due to its greater relative increase in density may resurface later in warmer waters. In areas laden with suspended solids, sedimentation will also occur. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

165 Chapter Seven Figure 6.3: Oil Spill Fate on Water Surfaces within Benisede Ground Water Modelling Regional Geology The study area (BCA) is located in the Niger Delta. The Niger Delta is underlain at great depth by the crystalline Basement. Structural analysis of the sediment fill shows that the Delta is made up of various fault blocks. The development of the Delta has depended upon the balance between the rate of sedimentation and the rate of subsidence. From the Late Cretaceous, the Basement underlying the Niger Delta started subsiding. Around the transition zone of the basaltic, oceanic crust to the granitic, continental crust, the crust broke up in many fault blocks. The fault blocks have shown an ongoing subsidence, while the troughs were filled up with marine, paralic and continental sediments. The study area is located in the south-westerly extension of the Benue Trough. From Eocene onwards, a global regression caused progradation of the Niger Delta over some 200 km distance and the present day coastal zone stretches over some 300 km. Progradation of barrier complexes was periodically interrupted by global sea-level rises, eleven of which formed delta-wide marine marker shales. EIA of Benisede Catchment Area FDP Phase 2 June, of 253

166 Chapter Seven Lithostratigraphy The sediments of the Niger Delta, which underlie the surficial Quaternary deposits, are broadly divided into three main lithostratigraphic units. These are in increasing age and depth: The Benin Formation. This is the youngest formation and consists of massive continental / fluvial sands and gravels. The Benin Formation is the continental, deltatop formation. The Agbada Formation. The Agbada Formation comprises shallow marine delta-front sediments. The basal Akata Formation. The oldest of the three formations, comprising shales, silts and clays. The Akata Formation is a deep marine pro-delta unit. (Reijers, et al, 1997; Adesida, et al, 1997). The study area is located between the Chain fault zone and the Charcot fault zone, the roughly north-east to south-west running fault zones which form the boundaries of the deepest part of the Niger Delta Basin (Reijers, 1994). In this part of the Niger Delta Basin, the greatest depths to the Basement are found. Around the study area, the base of the Akata Formation is found at a depth of over 12,000 m deep. The Akata Formation is approximately 6,000 m thick. The overlying Agbada Formation is approximately 4,000 m thick. The Benin Formation reaches its greatest thickness of approximately 2,000 m in the centre of the trough. The Benin Formation deposits are grading downwards into, or lie unconformably the Agbada Formation (Reijers, 1994). The significant formations for the hydrogeology of the study area are the Benin Formation and the Surficial Deposits: The Benin Formation The Benin Formation extends across the whole Niger delta and beyond the present coastline. It consists mainly of sands, with shale and gravel intercalations, fluvial distributary channels, marshes and swamps (Reijers, 1997). The sands are essentially fresh water bearing and form the main aquifer complex. Due to the stratified nature of the Benin Formation, with many clay/shale intercalations, this water bearing unit can be EIA of Benisede Catchment Area FDP Phase 2 June, of 253

167 Chapter Seven sub-divided in numerous aquifers. In the lower delta, the Benin Formation is covered by swamp deposits and abandoned beach ridges. The Surficial deposits The Quaternary delta-top deposits in the lower delta show a clear zoning according to their depositional environment. Running from approximately 50 km to the north-east of the study area to the south-west the following sequence of surficial deposits can be distinguished as follows: Late Pleistocene - Early Holocene Sombreiro-Warri Deltaic Plain Characterised by dry land with abundant swamp zones. Holocene - Recent Lower Deltaic Plain Mangrove Swamps Methodology Two Groundwater Modelling Systems (GMS) software s (MODFLOW and MOPATH) were used interactively for the simulation of groundwater flow and impact simulation in the Benisede Catchment Area. MODFLOW is the most widely used 3D groundwater flow model. MODFLOW can represent the effects of wells, rivers, streams, drains, horizontal flow barriers, evapotranspiration, and recharge on flow systems with heterogeneous aquifer properties and complex boundary conditions to simulate groundwater flow. Using GMS, the user can select a single cell or a series of cells and then quickly define the hydrogeologic characteristics and/or boundary conditions using interactive dialog boxes. In addition, a spreadsheet dialog can be displayed, allowing the user to edit the values for each individual hydrogeologic characteristic for the entire model. Input data were imported, and interpolated from a sparse set of scattered data points. MODFLOW simulation approach for this study was conducted using the conceptual approach. MODPATH is a 3D particle tracking model that computes the path a particle takes in a steadystate or transient flow field over a given period of time. MODPATH uses the head values and cell-by-cell flow terms computed by MODFLOW, in addition to the soil porosity, to compute the movement of each particle through the flow field. By specifying individual particle EIA of Benisede Catchment Area FDP Phase 2 June, of 253

168 Chapter Seven locations, MODPATH computes the location of each particle at any instance in time. Both forward and backward tracking can be performed by MODPATH. The other data used for the groundwater studies were stratigraphy / lithology of the subsurface soil, hydraulic properties of the Geologic formation, hydraulic Conductivity (K), Porosity, discharge, number and thickness of the formation, groundwater levels, depth of wells, surface water levels, as transmissivity, leakance and coordinates of the well locations as well as flow direction of groundwater. Results Stratigraphy and Groundwater Characteristics The area is part of the Western flank of the Niger Delta. The Age is Recent. The horizon of study, (0-20m) exposed by study wells is composed of coastal plain sand which are loose and homogenous, having not undergone any amount of lithification or diagenesis. This homogenous part is covered by a thick (0-5m) cover of peaty alluvial material which completely masks the general subsurface geology. Lithostratigraphic correlations of borehole logs shows that the formation underneath the study area is made up of an intercallation of peat, clay and sand beds with clayey sand lenses and sandy clay lenses varying in thickness within relatively short distances. This observed trend in the stratigraphy is typical of a prograding deltaic environment. The sands are very fine to medium grained Groundwater Flow Groundwater levels are highest around northern part of Benisede, intermediate around south-eastern and lowest in the south west of Benisede. As indicated in Fig 6.4, groundwater will therefore flow in the southerly direction (in the South South direction). EIA of Benisede Catchment Area FDP Phase 2 June, of 253

169 Chapter Seven Groundwater Flow Direction FIG 6.4: GROUNDWATER FLOW DIRECTION MODEL FROM A POINT SOURCE Impacts on Groundwater Overburden Protective Capacity The protective capacity of an overburden overlying aquifer within Benisede is proportional to its hydraulic conductivity but the high clay content within the area generally correspond with low resistivities and low hydraulic conductivities. Hence, the protective capacity of the overburden in the area is considered being proportional to the longitudinal unit conductance (S) defined as the ratio of the overburden thickness to its resistivity. The sand aquifer in the area is overlain by a variably thick overburden (topsoil/clay) whose longitudinal conductance is presented in Table 6.8. Table 6.8: Overburden Longitudinal Conductance and the Protective Capacity Overburden Thickness Longitudinal Conductance (mhos) Protective Capacity Excellent Excellent EIA of Benisede Catchment Area FDP Phase 2 June, of 253

170 Chapter Seven Excellent Excellent Excellent Excellent (Protective Capacity Rating Based on Rennet, 1976) This indicates that the overburden capacity rating is excellent therefore, the groundwater beneath is significantly protected from surface or near surface source of spill or pollution. The sand aquifer may be polluted via base flow within the canals. Soil Corrosivity The formation of corrosion cells, which can lead to severe corrosion failure, is known to be associated with low resistivity. Low electrical resistivities are indicative of good electrical conducting paths arising from reduced aeration, increased electrolyte saturation or high concentration of dissolved salts in soil. Soil resistivity can therefore be classified in terms of the degree of soil corrosivity as shown in Table below. Table 6.9: Classification of Soil Resistivity in Terms of the Corrosivity Soil Resistivity (ohm-m) Soil Corrosivity Up to 10 Very Strongly Corrosive (VSC) Moderately Corrosive (MC) Slightly Corrosive (SC) 180 and above Practically Non-Corrosive (PNC) (Based on Baeckmann and Schwenk, 1975 and Agunloye, 1984) The soil resistivity at a depth range of m (normal depth of burial of oil/gas pipes) varies from ohm-m. The degree of soil corrosivity based on Table 6.9 above is very strongly corrosive. Metal pipes buried within Benisede field are highly susceptible to corrosion hence, likely to release oil to the environment. Generally confining clays may restrict the vertical movement of oil spilled, preventing the mixing of waters between the various aquifers. Hence, spill that occurs underground (buried pipeline) within the clay zone will be confined. The overlaying clayey/peaty clay will prevent direct infiltration of possible pollutants to the aquifer, however, the water EIA of Benisede Catchment Area FDP Phase 2 June, of 253

171 Chapter Seven table is shallow, and in case of leakages within areas that have been open up through the creation of artificial canal and slots to the ground water. Impacts will occur and flow along the direction of groundwater flow. Backward impacts will be minimal and will take over ten years to impact up to a distance of 25m (see Fig 6.5). Impacts Flow Direction FIG 6.5: IMPACT FLOW DIRECTION MODEL FROM A POINT SOURCE EIA of Benisede Catchment Area FDP Phase 2 June, of 253