Experiences in the Development of Shale Gas

1. Experiences in the Development of Shale Gas

2. Experiences in the Development of Shale Gas • Presentation Outline • General background: Unconventional gas plays in the US • SLB’s general evaluation workflow • Data Audits and Initial Design • Pilot Well Strategy • Confirmation and Development Options • Optimization and Maintenance • Exploitation • Conclusions

3. Influence of Prices and Technology Unconventional Gas Conference & Exhibition Stephen A. Holditch September 30, 2008

4. Influence of Prices and Technology Unconventional Gas Conference & Exhibition Stephen A. Holditch September 30, 2008

5. Influence of Prices and Technology Unconventional Gas Conference & Exhibition Stephen A. Holditch September 30, 2008

6. 6 5 Yearly well count 4 3 Barnett Shale Production (BCFD) & Well Count 2 1 0 Number of wells Barnett Shale Gas Production Growth

7. SEECOS’ Fayetteville Shale Gas Production Growth

8. Fayetteville Shale Gas Production Growth

9. Experiences in the Development of Shale Gas • Presentation Outline • General background: Unconventional gas plays in the US • SLB’s general evaluation workflow • Data Audits and Initial Design • Pilot Well Strategy • Confirmation and Development Options • Optimization and Maintenance • Exploitation • Conclusions

10. Tight Shale Work-Flow External data collected and considered for analysis. Must have core or cuttings for TRA and basic Cluster normalization. Identify play as viable Identify critical data gaps to be filled in initial well(s). Bring all data into Petrel and begin reservoir model 1st new well is a data rich well designed around filling gaps in data audit and employing the key technologies to prove commercial viability and completion design Build up Petrel model and design seismic survey for Ant Tracking correlation for field development strategy. Develop initial stress model and resulting model post 1st stage development for optimum infill drilling and re-frac stage Spot check with side wall cores Test tandem well stimulation approach Monitor with microseismics Spot check resulting stress and anisotropy changes from development and plan re-frac sequence.. Prove repeatability and completion concept and performance OR React and re-design and treat as 1st well.

11. We love models… Models allow us to take a solution and apply it everywhere. Or do they? Barnett The art of models is in the application.

12. Early Phase – Data Audit+ Gather the available data and conduct actual lab measurements when needed to compliment the petrophysics. Where Core is not available cutting may be of sufficient quality. • Reservoir Quality • Core to Log Integration • Shale Classification and Cluster Analysis • Identify missing data and Pilot Strategy Data Audit/M&A Support Review Reservoir Model Migrated into Petrel External data collected and considered for analysis. Must have core or cuttings for TRA and basic Cluster normalization. Identify play as viable Identify critical data gaps to be filled in initial well(s). Bring all data into Petrel and begin reservoir model

13. Rock ≠ Rock ≠ Rock TRA Analysis Initial analysis from precise sampling of core with TRA conducted to describe the heterogeneity and precise attributes. Two Goals: 1. Reservoir quality in the various units 2. Completion quality for each productive interval

14. argillaceous siliceous calcareous Three Layered Core-Based Shale Classification Layer 1: Grains >4 μm TIGHT GAS SANDS AND CONVENTIONAL RESERVOIRS Layer 3: Organics Layer 2: Matrix Composition increasing silt & sand SHALE RESERVOIRS

15. Reservoirs: Thin Section Examples Marcellus, Pennsylvania Montney, Alberta Canada Bakken Shale, North Dakota Sandstone, offshore South Africa Mancos Shale, Uinta Basin Penn Shales, West Texas

16. Applications: Multiwell analysis for coring and sampling Aerial View Cluster analysis coupled with materials profiling allows us to evaluate log-scale heterogeneity for reservoir quality and completion optimization. You need both

17. Heterogeneity is a Key Issue Argillaceous (NR) Nodules Problem: • Reservoir quality: Where & how is gas stored? • Net Value: What is the effective gas in place? • Accessibility: What is the relationship between high gas concentration and containment? • Production and Recovery: How discontinuous is the stress profile? How discontinuous is the pressure profile? What are the relevant discontinuities? Is the system stiff (open vs. closed fractures)? What is the variability in rock properties? What is the degree of anisotropy? Is brittleness an indication of anything fundamental? Siliceous/Arg-illaceous (R) Siliceous (R) Calcareous (NR) Mix. Siliceous Argillaceous (R) The biggest issue in tight gas reservoirs is not low permeability….It’s heterogeneity.

18. First Pilot Well(s) Consider what data is in hand and the quality against the uncertainty and design the Pilot data strategy • Hole Core or infill with Side Wall (rotary) • Horizontal or Vertical Assumptions • Heterogeneity • Completion Strategy • Do you have containment? • Are multi stages feasible? • Fluid and proppant selection First Pilot Well to Evaluate Shale and Geol Confirmation 1st new well is a data rich well designed around filling gaps in data audit and employing the key technologies to prove commercial viability and completion design

19. Anisotropy and Fracture Containment Isotropic Blue (v) Anisotropic Red (Eh, EV, nh, nV)

20. Note: You must have core measurements of stress in 3 axis to cover the remaining unknowns

21. Staging the Stimulation Anisotropic Stress Profile Isotropic Stress Profile

22. Pilot Update - Development A second pilot well to optimize or confirm the completion is recommended • Horizontal vs. Vertical • Completion Optimization • Update Model • Plan for periodic checks Field Optimization • Upscale Clusters into Petrel and Seismic • Visage Coupled Stress Model • Fine tuning risks of heterogeneity • Well Placement • Frac geometry • Simultaneous frac planning • Consider forward stress modeling First Pilot Well to Evaluate Shale and Geol Confirmation Second well-offset to prove commerciality and development strategy Update model and tune Cluster systems from old wells Build up Petrel model and design seismic survey for Ant Tracking correlation for field development strategy. Develop initial stress model and resulting model post 1st stage development for optimum infill drilling and re-frac stage Prove repeatability and completion concept and performance OR React and re-design and treat as 1st well. Continue to pilot across the play

23. TRA Real Time Support Core to log integration allows you to tag intervals along the borehole of a non cored well with similar patterns. Log data can be transmitted to town as you identify dissimilar patterns you can quickly take a sample in real time to insure a proper evaluation of the units on the subject well. A rotary sidewall coring tool is used and the sample is returned to the lab for analysis

24. Basin-scale 3D Visualization (Petrel Models ) Compílanse Gross Thickness

25. Completion Options SPE 119635 SPE 110562

26. Fiber Diversion Technology“StimMore”

27. Asset Optimization Plan for heterogeneous challenges and include a degree of periodic checks • Logs to confirm stress distributions and anisotropy • Cluster updates as needed • Update seismic scaling of clusters Field Optimization • Determine if Simultaneous well treatments will bring improvements. • Monitor stress changes with Sonic Scanner and update Visage Model • Plan second stage of drilling or refrac based on the Petrel Model Optimization of well placement and completions Exploitation Spot check with side wall cores Test tandem well stimulation approach Monitor with microseismics Spot check resulting stress and anisotropy changes from development and plan re-frack sequence..

28. Design with Stress in Mind Figure 4 SPE 119635

29. Conclusions • Shales are heterogeneous in both reservoir and mechanical properties. This is the most important property to understand. • The workflow presented has been proven (in part) to be most effective helping clients increasing their ultimate recovery by 50-100%. • We continue to evolve this workflow as we learn from new applied technology. • Proper characterization requires data and sampling on all prospective zones. • Not all zones are good reservoir, not all high resistivities are good reservoir. • Containment zones may be hydraulic seals or they may be zones within the shale. Worst case there is not reliable containment. • Not all zones react the same way with completion fluids.

30. Conclusions • Field Optimization • Use core-to-logs integration (MP2) to define a baseline for testing and also increases sampling efficiency • Establish the well placement and completion strategy with an integrated plan of the current and forward modeled stress state • Do not assume what works in one shale applies to a different one and be ready to realize this in different sections of a large shale play.

31. Green River Barnett Woodford White Specks Mancos Wolfcamp Niobrara Haynesville Marcellus Antrim Montney The Art of Modeling is in the application