Unconventional Challenges: Integrated Analysis for Unconventional Resource Development Robert Gales VP Resource Development

Transcription

1 Unconventional Challenges: Integrated Analysis for Unconventional Resource Development Robert Gales VP Resource Development

2 Opening Remarks The Obvious Fossil fuels will be the main energy supply, accounting for about 80% for the foreseeable future. Unconventional resources will play a role in supplying demand growth: Heavy Oil Tight Gas Sands / Carbonates Basin Center Gas Coal Seam Gas (CSG/CBM) Shale Gas / Shale Oil In-Situ Combustion Oil shale Methane Hydrates Greening of energy emphasizes gas Source: Drilling Contractor 2004

3 World Unconventional Gas Estimates Recent total Reserves (ARI 2010) 16,500 1,000 +Sour-260?? 2,313?? Source: NPC Global Oil and Gas Study 2007 (Based on Rogner 1997)

4 Global Distribution of Unconventional Gas

5 Agenda Unconventional Challenges Integrated Project Flow Reservoir Evaluation Brief Completion & Production Summary

6 Unconventional Gas Reservoirs: Common Characteristics Typically cover large areas, often quite thick / stacked reservoirs Low porosity, Low matrix permeability Often naturally fractured (cleated) Lateral Heterogeneity multiple depositional environments Source rock and reservoir closely related or same Traditional migration paths, traps, seals no longer apply Gas stored by sorption and / or compression Log Analysis provides Partial Answers; Core Analysis is Required Horizontal wells often used Multi-Stage stimulation often required Typically easy to find, Difficult to quantify. More challenging to extract! Not every unconventional resource is a good reservoir.

7 Unconventional Gas Reservoirs: Challenges Reservoir Quality Gas in-place Volume Permeability to Gas (Oil) Rock Mechanical Properties Fracability High initial rates, Rapid decline to 70% year 1 Positive long productive life Low recovery factors on traditional spacing From 160 acre to 20 acres, now 10 acre pilots Horizontal wells, multi-stage fracs Relatively high development costs Increased infrastructure and surface impact Require greater drilling density or horizontal wells Completion costs often ~ equal to drilling costs

8 Unconventional Gas Reservoirs: Challenges (cont.) Requires a competitive economic environment Available drilling and completion infra-structure Focus on D & C engineering manufactured wells Low risk once specific area and solution defined In- fill drilling, re-stimulation Environmental Considerations Water, Access, Noise Reserves quantification Ultimate size and productivity

9 Unconventional Gas Resource Project Development: Process Good Science leads to Good Engineering Predict Determine Reserves and Productivity Core and Core Analysis Mud Logging Logging & Testing Micro-seismic Reservoir Evaluation Exploration Plan Go/ No Go point $ Pilot Optimize for Execution Finalize Field Development Plan Drilling Completion Type OH/CH - Stimulation Production Testing Development Plan Go/ No Go point $ Produce Increase well construction efficiency and Maximize Production Drilling / Directional Completion / Stimulation Lift / Optimization Water Treatment

10 Depth Common Information Requirements (partial list) Thickness Lateral distribution/continuity Reserves (Gas / Oil in Place) Pressure Recovery Factor Productivity absolute and relative permeabilities Rock Mechanics, especially Tight Gas Sands and Shale Gas Mineralogy & Deposition information (XRD, XRF, SEM, petrography) Geochemistry - Total Organic Carbon / Level of Maturity Timeliness of data and analysis Cost versus value / Cost versus risk Actionable Data Reduce Uncertainty

11 Data in an Ideal World Lots of Core and Analysis Mud Logs and Cuttings Analysis Basic Triple Combo plus Spectral GR if shale gas Porosity, Sw, zone thickness, reserves Lithology / Mineralogy for TOC, kerogen volume and gas in place validated with core Image logs for natural fractures and depositional information Fracture density and width for well placement and orientation Image petrophysics - rock types, permeability Dipole sonic for mechanical properties inputs confirmed with core for completion design and drilling improvement Micro-seismic for stimulation effectiveness and reservoir drainage for future well placement Post-frac pressure build up for stimulation effectiveness and reservoir drainage Data requirements aligned with reservoir type and goals

12 Unconventional projects: Project Execution Good Science leads to Good Engineering Predict / Pilot Predict Basin Study / Screening Seismic, logs, core, cuttings Produce Exploration Key Vertical Wells Vertical Go/ No Go point $ Horizontal Development Wells Key Step-Out Wells Core and Core Analysis Cuttings SRA TOC/Vo/TM Drilling / Directional GC Tracer (with XRF/XRD) GC Tracer (with XRF/XRD) Cuttings SRA TOC/ Vo/TM Wireline Logging Triple Combo with NGT Dipole Sonic & Images Testing (especially coals) Reservoir Evaluation Completion / Stimulation Design Logging LWD SAGR KEY WELLS - Wireline Logging Triple Combo & Images Testing (especially coals) Reservoir Evaluation Completion / Stimulation Design Perf - Connex Charges (Cement Evaluation) Stimulation with Zone Select & SandAid Micro-Seismic Frac Effectiveness Reservoir Drainage Production Testing/Logging Field Development Plan Go/ No Go point $ Updated: Reservoir Evaluation Field Development Plan Perf - Connex Charges (Cement Evaluation) Stimulation with Zone Select & SandAid KEY WELLS - Micro-Seismic Frac Effectiveness Reservoir Drainage Lift / Optimization Production Testing /Logging

13 Unconventional Core Analysis: (partial list) Right measurements for the reservoir: Gas Content of Coal or Shale Gas/Oil Adsorbed Gas Free Gas Langmuir Isotherm Geochemistry - Total Organic Carbon / Level of Maturity Vitrinite Reflectance XRD/XRF/SEM for Lithology Rock Composition & Description / Clay mineralogy & fractions Rock Property Quantification Porosity, Perms, Saturations Absolute and Relative Permeability Fluid sensitivity for completions Rock Mechanics for stimulation design Proppant Embedment

14 Critical Geochemical Parameters: TOC and Thermal Maturity TOC Measures the present day organic richness of a rock Maturation parameters are indicative of the maximum paleotemperature that a source rock has reached The standard for maturity reporting is Vitrinite Reflectance (% Ro) Quality TOC (wt%) Poor <0.5 Fair 0.5 to 1 Good 1 to 2 Very good 2 to 4 Excellent >4 Vitrinite Reflectance, Ro Immature <0.6% Oil Window % Wet Gas Window % Dry Gas Window 1.4-~3.2% Gas Destruction >~3.2% Threshold Shale Gas Threshold Shale Oil (?)

15 Wellsite Geoscience: Alternate data for Completion Design Traditional Mudlogging Wellsite Services Wellsite Geosciences Services GC Tracer TM (Gas Ratio Analysis - Productivity Index) Source Rock Analyzer (TOC, maturity, expelled hydrocarbon) Elemental / Mineralogy composition X-Ray Fluorescence (XRF) X-Ray Diffraction (XRD) Computed mineralogy for brittleness input to stimulation design CEC for improved Sw computation Depositional information for sweet spots Estimation of reserves and initial production (calibrated with production history) Real time information for input into completion design 24

16 GCTracer TM Barnett Shale Gas Well: Productivity Prediction & Completion Design GC Tracer Indicates areas of greater Matrix Permeability C5+ range is very important 4 horizontal wells, 2 upper Barnett, 2 lower Barnet GC Tracer TM Gas Ratio analysis used to predict best producing wells Results confirmed with production, now input to completion design A-1 A-2 A-1 B-1 A-2 B-1 B MMCF/DAY 3.5 MMCF/DAY B MMCF/DAY 3.7 MMCF/DAY A-1 A-2 B-1 B-2

17 Identification of Ductile Zones Clays Initiation of a frac proved unsuccessful in this zone with >50% clays MINERALOGY Quartz Carbonates Clays Others 1 sample per 20 TPH / TOC (0-10) S1 S2 TOC 26 26

18 Depth Package Package F Package E Package D Package C Units Unit F7 Unit F6 Unit F5 Unit F4 Unit F3 Unit F2 Unit F1 Unit E2 Unit E1 Unit D3 Unit D2 Unit D1 Unit C3 Unit C2 Unit C1 ChemoGR 0 API 220 GR 0 API 220 Well Bore LaserStrat Relative Brittleness Index (Fracablitiy Index) LaserStrat Predicted Mineralogy Brittleness Mineralogy Real-Time Mineralogy & Relative Brittleness Red trace shows calculated elemental gamma for sample QC After Buller et al. (2010)

19 Interpretation Unconventional Open Image Fractures Applications Fracture Characterization Orientation Frequency or spacing/clusters Conductivity or permeability Connectivity Changes during injection / production Effect on stimulation / production Stress Orientation (Calibrated with core) Textural Analysis Facies Characterization Flow Unit Determination HDEN GR SFE Fracture filled with highly resistive material - calcite High Res Density (HDEN) GR & High Res Resistivity (SFE) Coal Enhanced Static Image

20 Marcellus Core Calibrated Log Interpretation 30

21 Integrated Shale Gas Example Raw Data Lithology / Volumetrics Mechanical Properties

22 Unconventional Gas: Well Completion and Production: Image courtesy Statoil/Hydro UBD often used to access reservoir or minimize formation damage in tight gas sands Horizontal wells dominate shale gas drilling Pad drilling in environmentally sensitive areas Reduce surface footprint and infrastructure costs Typical well cost distribution: Nearly 50% for completion High completion costs have driven multi-stage stimulation innovation and efficiency 32

23 Micro-seismic Monitoring Frac Well Treatment Well Array Remote Well Observation Well Array Microseismic Hypocenters Induced microseismic activity along fractures is mapped using a velocity model and P/S wave arrival time Measure length, height, width, azimuth and overall frac complexity Provides information on reservoir drainage future well placement Recorded from a remote well or from inside the treatment well Tools deployed on wireline, e-coil or permanent Time component shows frac propagation in time with real time processing available 36

24 Micro-seismic Mapping: Frac Orientation - Reservoir Drainage Out of zone growth Conjugate Joint Sets Farthest events are 3,000 ft from observation well Linear barriers exist both sides of the induced fractures Reservoir Drainage information for field development

25 Incorporation into Reservoir Model Induced fractures are required due to extremely low permeability.

26 Summary Unconventional resources CBM, Tight Gas Sands and Shale Gas/Oil are technically viable resources: Provided political and economic conditions exist to encourage development Unconventional Game Changers: Improved reservoir understanding allows identification of sweet spot seismic processing through advanced mud logging Improvements in horizontal drilling longer laterals at lower cost Improved stimulation efficiency - increased stages, 24/7 operations, improved additives Following a process of Good Science at the beginning provides for Good Engineering for successful unconventional project development.

27 Thank you for your attention 42