Week of Mar. 22, 2004/US$ International Petroleum News and Technology / Ethylene Report

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1 Week of Mar. 22, 2004/US$10.00 International Petroleum News and Technology / Ethylene Report MTBE issues broader than liability protection debate Seismic weight drop quest leads to improved data, costs, footprint Management plan reduces heavy-oil waste costs NO x -trading recoups emission-retrofit costs for compressor engines Copyright by PennWell Corporation

2 D RILLING & PRODUCTION AMERIVEN PROJECT Fig. 1 C a r i b b e a n S e a TRINIDAD and TOBAGO Management plan reduces heavy-oil waste costs Neal Kebert Alfonso Arrocha Gustavo Ellis Petrolera Ameriven SA Barcelona,Venezuela Keith Browning Halliburton Energy Service Group Houston Kevin Redfern Gonzalo Bernal Halliburton Energy Service Group Maturin,Venezuela J.D.Thomason Halliburton Energy Service Group Barcelona,Venezuela Production A waste-management plan reduced the cost for handling drilling and production wastes for the Hamaca heavyoil project in the Orinoco belt of Venezuela (Fig. 1). The project operator, Petrolera Ameriven SA, is a joint venture of ConocoPhillips 40%, ChevronTexaco Corp. 30%, and Petroleos de Venezuela SA (PDVSA) 30%. To implement the plan, Ameriven designed its central waste-treatment facilities (CTRD, or Centro de Tratamiento y Recuperación de Desechos) with the technical support of two units of Halliburton Energy Services Group: Halliburton Total Fluids Management and Baroid. The CTRD receives and processes both heavy-oil drilling and production waste generated by the Hamaca operations (Fig. 2). Ameriven expects that during the 30-year project life, the facility will process wastes from wells. Its current development phase produces about 80,000 b/d of extra-heavy crude, and this will increase to 190,000 b/d during the commercial phase. V E N E Z U E L A Drilling Cuttings Drilling fluid Oil contamination in drilling fluid Cement and related fluids Ameriven heavy-oil project WASTE STREAMS Table 1 Production Oily sludge from: Cleaning of bottom tanks Slop oil Electrostatic separators Pipeline cleaning Other wastes: Completion fluids Contaminated soils (oil spill) Four R s The primary CTRD objective emphasizes four R s: reduction, reuse, recovery, and recycling of the waste streams. This strategy already has realized important cost savings through the consolidation of waste treatment at one location near the source and implementation of efficient waste-management practices. Using an innovative design, the Baroid and Ameriven teams have increased waste-management efficiency by eliminating steps in the physical handling of drilling and production wastes. The CTRD has processed waste from more than 120 wells to date, in accordance with the minimization strategy (four R s) and in compliance The CRTD facility receives both heavy-oil drilling and production wastes (Fig. 2).

3 with the Venezuelan environmental regulations. 2 Ameriven currently estimates that the plan has reduced waste management and disposal costs at this site by 22% since operations began. All treatment takes place at one facility near the operations generating the waste. This helps reduce the overall cost for the entire project and simultaneously decreases potential risks associated with heavy-oil 3 m drilling and wastemanagement operations. 59 m 42m 12 m 8 m Site selection Table 1 lists the typical drilling and production waste streams coming from the Hamaca operations. Before the construction and operation of the CTRD, companies in the Orinoco area of Venezuela had few waste-disposal options, and only a few companies possessed appropriate experience to provide wastemanagement services. Previously, the main options, landfarming and landspreading, required transporting materials for long distances, thus increasing environmental and safety risks and the costs associated with waste disposal. Strategically situated on an old drilling location within the project block, the 1.3-acre CTRD facility was designed to reduce waste-handling activity at the rig site, thereby helping to increase operational efficiency and lower overall costs. The CTRD provides optimized treatment capacity through use of multifunctional, interchangeable equipment and treatment technologies (Fig. 3). 4 Table 2 shows the components selected and integrated based on the three key functions of environment, economics, and technical. The CTRD is on an old drilling location with low environmental sensitivity, a remote, unpopulated area that previously was deforested and surfaced with asphalt. Therefore, CTRD construction 12 m Mud store 500 bbl tanks 2 m Completion fluids 500 bbl tanks 5 m Boiler 4 m 3 m 6m Generator 13 m 8 m Diluent tank Water store 11 m Fuel tank Chemical store Two phase fluid recovery tank did not require removal of pristine growth and habitats. Furthermore, runoff is controlled easily because the site slope is less than 2%. The groundwater table at the site is more than 80 m deep, and the stratigraphic evaluation showed that the site has 1.5 m of sandy topsoil that rests on m of clay. 91 m 17 m Ameriven derived many economic benefits by centralizing the waste-management function with one service company at one location. These benefits include economies of scale, the continuous availability of specialized technicians, a useful selection of related equipment and chemicals, energy conservation, and constant environmental CTRD SCHEMATIC Fig. 3 Water treatment Water treatment Water store 500 bbl tanks 11 m 11 m 25 m 12 m Black water plant Camp water Filters and Hydropneumatic Catch tank Old well Mixer tanks To COB Dewatering system Camp accommodation THREE KEY FUNCTIONS Table 2 Environmental Economical Technical Volume of waste Transportation Global technologies generated Equipment available Physicochemical Fuel Equipment specicharacterization and Chemicals fications for voltoxicity, including toxicity Fertilizers ume generated characteristic leaching procedure (TCLP) and numerous other HSE tests Venezuelan environmental regulations Waste minimization 4R s Experience of personnel Solids catch tank W i n d d Note: Recipient soils for landfarming and land spreading are adjacent to facility. i r e c t i o n Vehicle access Cell 1 Cell 2 Cell 3 Cell 4 monitoring of on and off site soil and groundwater. Also significant costs were saved from a reduced need to transport waste materials long distances for disposal. The CTRD has good access roads and is equidistant from the waste generators such as well pads, central operating base, and pipelines. Adjacent to the CTRD are the recipient soils that have the required environmental conditions for landspreading and landfarming (Fig. 4). The area has sufficient space for fully installed and implemented treatment technologies needed for waste minimization management. 10 m Truck access 40 m

4 D RILLING A2 A1 Disposal technologies The team evaluated the following waste disposal technologies as candidates for the CTRD: Dewatering. Centrifuging to recover oil from sludge. Incineration. B & PRODUCTION LANDFARMING, LANDSPREADING AREA Fig. 4 D C Borrow pit Platform Cell Size area Function area, sq m A1 Area for biotreatment of solids from centrifuging process 79,800 A2 Area for biotreatment of oil contaminated sands 27,600 B Area for oil contaminated cuttings from horizontal section 62,700 C Surface-hole cuttings nonoil contaminated 22,100 D Oil contaminated cuttings from elbow of build section 40,900 Rig A produces drilled solids from the shale shakers, desander, desilter, and centrifuges (Fig. 5). Thermal desorption. Stabilization-solidification. Biotreatment (landfarming, composting, and biopiles). Burial. Well injection. Reuse of some wastes as construction materials for well pads and access N roads, or as treated fill material for the environmental restoration of abandoned pits in the Hamaca area. The CTRD receives drilling and production wastes generated from four major sources: waste from the central operating base (COB), drill solids from Rig A, drilling fluid from Rig A and Rig B, and completion fluids from production. The facility can process up to 2,000 b/d of drilling and completion fluids, and it has storage and treatment capacities for 2,000 bbl of solids. COB waste Three main sources generate the COB waste: 1. Crude storage tanks (60% solids, 32% crude, and 8% water). 2. Electrostatic separators (28% solids, 58% crude, and 14% water). 3. Pipeline cleaning (no samples are yet available but Ameriven expects the waste to be similar to the separator samples). Based on these sample results and hot-spin tests, the waste is separated into two distinct phases (solids and fluid). Super vacuum trucks, 70 bbl/truck, pick up the COB waste and then deliver and discharge it into two 500-bbl agitator tanks. One receiving agitator tank holds about six truckloads plus about 15% diluents (light crude). The resultant mixture is heated to about 55 C. (131 F.) and continuously agitated before being pumped at gpm to centrifuges, set up in series or parallel depending on final product-quality requirements. The resultant fluid discharge is analyzed to ensure it contains no more than 5% solids. It is then stored in two 500-bbl tanks before being transported back to the COB. At the COB, the fluid is mixed with the dilute crude before separation of the associated gas and produced water. Analysis ensures that the solids discharge complies with the Venezuelan environmental regulations on the level of oil-on-solids (OOS). The discharged solids are then bulked up with sand and landfarmed with a tractor to a depth 30 cm, as per Venezuelan landfarming requirements.

5 Additionally, Ameriven reuses the treated waste construction material in well pads and access roads (as first priority), and as fill material for old pits. Rig A solids The solids generated on Rig A (Fig. 5) come from two main sources: 1. Drilled solids from the shale shakers, desander, and desilter with 30-50% mud-on-cuttings (MOC). 2. Solids discharge from two centrifuges with 10-15% MOC. Supervacuum trucks (70 bbl/truck) pick up and deliver the solids to four 500-bbl dry beach cells. A purpose-built sump collects the whole mud run-off, which is then pumped to one of the 500-bbl mud storage tanks prior to being dewatered. The solids are dried as much as possible on the dry beach area, prior to being bulked up with sand, if necessary, and landspread with a tractor in the specified cell in the CTRD (Fig. 4). The landspreading practices comply with Decree 2635 of the Venezuelan environmental regulations. The treated material is reused in a manner similar to the COB solids discharge previously described. Centrifuges and dewatering units are part of the waste treatment system (Fig. 6). Drilling fluid Drill water and native mud with bentonite sweeps is the typical top-hole drilling fluid, while the horizontal section has a specially formulated drilling fluid that can incorporate 8-10% oil contamination from the reservoir. Depending on the quality of the drilling fluid received, the CTRD can process 1,500-2,000 bbl/12-hr working day. Two main sources generate the drilling fluid: 1. Daily dilution to the active system, generating excess volume. 2. Change out of the complete drilling fluid system. The CTRD receives fluid from both sources and stores it in one of the five 500-bbl-capacity mud storage tanks. From there, the fluid enters a dewatering system (Fig. 6), where adjustments are made to the ph of the excess fluid. Flocculants and coagulants are added to the input stream of the dewatering units, and centrifuges remove the flocculated solids. Clarifying agents then treat the resultant fluid before it is transferred to the five 500-bbl water-treatment storage tanks. The rig receives more than 80% of the treated water for reuse in the active mud system, rig clean up, and dust control. The rest is diverted to onsite irrigation. A tractor landspreads the solids generated and the reuse complies with Venezuelan environmental regulations. Completion fluids The process can handle 1,500-2,000 bbl of completion fluids/12-hr working day, depending on the quality of fluid received and completions fluids from up to 10 wells at a time. The fluid is delivered in 2,000-bbl batches. Each batch typically has 5% solids, 94% water, and 1% crude or 20% solids, 72% water, and 8% crude. In the first scenario, one of the four 500-bbl completion fluid tanks receives the fluid. From there, a dewatering system processes the fluid and adjustments are made to the ph of the fluid. Flocculants and coagulants are added to the dewatering-unit input stream, PROCESSED VOLUMES Fig. 7 Drilling fluid, bbl 35,000 30,000 25,000 20,000 15,000 10,000 5,000 0 Dewatering mud volumes Fig. 7a Build section Volume total Cuttings, bbl/well Fig. 7b 20,000 Cuttings volume 16,000 12,000 8,000 4,000 0 F4 F5 E4 C4 G5 H5 F4 F5 E4 C4 G5 H5

6 D RILLING and centrifuges remove the flocculated solids. If the resultant fluid contains less than 3% crude, it can be treated with aluminum sulfate and clarifying agents and then transferred to the water-treatment storage tanks. As with the drilling fluid, the rig receives more than 80% of the treated water for reuse in the active mud system, rig clean up, and dust control. The rest is diverted to onsite irrigation. In the second scenario, if the received fluid contains more than 8% crude, it will be processed through the previously described two-phase process with the resultant fluid being returned to the COB where separation of the oil from the water phase takes place. In both cases, tractors landspread the generated solids, and reuse complies with Venezuelan environmental regulations. Operational, cost advantages The CTRD established for the Hamaca project in late 2002 demonstrates the value of total-fluids-management operations. Through optimized solids control, efficient waste handling, treatment, transport, and disposal, Ameriven has reduced to 6.3 days from 14.2 days the overall time to drill the surface, build, and horizontal sections of a well. Since project start-up, the cost of drilling fluid and waste management has decreased by 36% (Figs. 7a-b). Because total fluids management service is a continuous improvement system, Ameriven expects further cost reductions. The treatment and disposal process complies with all permit requirements and includes such HSE compliance testing as: TCLP (toxicity characteristic leaching procedure) for determining the mobility of contaminants in a waste when it is exposed to the natural elements, principally rainwater percolation. Metallic elements test for determining the content of metallic elements of interest in fluid sample. TPH (total petroleum hydrocarbons, mineral oil, and grease) test for & PRODUCTION determining the quantity of petroleumbased hydrocarbons present in the sample. Laboratory centrifuge hot-spin pilot tests performed on all fluid received for determining the composition and consequently the most efficient method of processing. This results in the exact quantities of diluents and temperature requirements being known and later applied, leading to a more efficient and cost effective process. SARA (saturate, aromatic, resin. and asphaltene hydrocarbons) and TPH tests for directly evaluating the landfarming process efficiency. CFU (culture formation unit) test for evaluating microbial activity and bacterial density, expressed as the CFU/g of soil. Respirometry (CO 2 production) test for determining the CO 2 production from biodegradation activity and with CFU indirectly evaluating the landfarming process efficiency. Paint filter test for ensuring that free liquid is not present in the solids centrifuged. Several integrated processes A thorough rig audit is one of several integrated processes implemented for the efficient disposal of drilling waste products. Solids-control equipment performance is a critical factor in waste reduction; therefore, each piece is evaluated for efficiency and mechanical competence. Often, operators can reduce the amount of solids-control equipment and improve efficiencies if the equipment is properly configured and modified for maximum efficiency. Other essential elements of total fluids management service include rig, field, and plant supervision, dewatering, water treatment, landfarming, and landspreading of processed solids and cuttings. Operators have seen significant improvements in drilling efficiency and lower waste-management costs from the total fluids management system in several fields throughout Venezuela. References 1. Operating Excellence Plan of Petrolera Ameriven (EH&S Management System); Waste Minimization Plan of Petrolera Ameriven 2. Waste Management: Law 55; Decree 2635; Wastewater Treatment: Decree 883; Atmospherics Emissions Control: Decree 638. The authors Neil Kebert is a senior drilling and completions engineer with ChevronTexaco Corp. and has worked on the Petrolera Ameriven project for 3 years. He has worked for ChevronTexaco or its predecessor companies for 21 years. Kebert holds a BS in petroleum engineering and an MBA. Alfonso Arrocha is corporate environment coordinator for Petrolera Ameriven, having worked for 24 years in environmental affairs in the petroleum industry. He holds a BS in chemical engineering and an MS in environmental studies, both from Universidad Central de Venezuela. Gustavo Ellis is upstream environment coordinator for Petrolera Ameriven. He has worked for 20 years in environmental affairs in the petroleum and aluminum industries. He holds a BS in urban planning from the University of Southwestern Louisiana. Keith Browning is operations leader-latin America for Baroid Surface Solutions/Halliburton Total Fluids Management. He has 16 years of experience in the petroleum industry and holds a BS in petroleum geology from Texas A&M University. Gonzalo Bernal is Venezuela services coordinator for Baroid Surface Solutions. He has 10 years of experience in solids control and waste-management services for oil field projects. Bernal holds a BS in petroleum engineering from the Universidad de América in Colombia. J.D.Thomason is business development leader for Baroid Venezuela. He has 14 years of experience in the petroleum industry and holds a BS in mathematics from the University of Oklahoma. Kevin Redfern is equipment asset supervisor for Baroid Surface Solutions Venezuela. He has 17 years of equipment maintenance in the mining industry and 14 years in the petroleum industry. Redfern has a full certificate in mechanical engineering from City & Guilds London Institute.