Bakken and Three Forks Logging Acquisition for Reservoir Characterization and Completion Optimization

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1 Bakken and Three Forks Logging Acquisition for Reservoir Characterization and Completion Optimization Ernest Gomez Peter Hook, Peter S. Kaufman and Stephen D. Sturm

2 Acknowledgements Bakken Consortium Members XTO (Headington) Brigham Continental Encore Hess Petro-Hunt Whiting Schlumberger North Dakota Oil and Gas Research Council

3 Outline Takeaways Target Identification Fractures Lithology Porosity and permeability Stimulation Optimization Rock properties Recommendations/Summary Fld Illite Qtz Ls Dol

4 Takeaways Bakken and Three Forks properties are variable: Lithology Fractures Matrix 3-D rock mechanical Measurement of these properties is important and can be used for: Target identification Model and optimize completions XTO Nesson State 42-36X (Three Forks)

5 Role of Core Serves as calibration for logging suites Lithology (XRD) Petrophysical properties (Ф, k and Sw) Anisotropic mechanical rock properties (YM, PR, UCS, stress)

6 Target Identification Fractures Lithology Matrix Porosity Permeability Qtz Fld Ls Dol Illite

7 FMI (Fullbore Formation MicroImager) Fracture Characterization Horizontal Well Fracture orientation, density, aperture and spacing Identification of fracture swarms for completion design Multi-axis caliper for swell packer design Identify lateral lithology variations Stratigraphic, structure and stress azimuth information

8 FMI - Nesson State 44X-36 Fractures Natural fractures sparse Occur In limestones (ELAN ECS) and zones of higher curvature Fracture permeability: microdarcy - nanodarcy Fracture porosity: 0.004% net phi Induced fractures

9 ECS (Elemental Capture Spectroscopy Sonde) Lithology Vertical and Horizontal Well Lateral target selection used in ELAN for pay evaluation Carbonate/Clastic lithology identification Clay volume Improved lithology - better mechanical properties and improved frac design

10 ECS Nesson State 42X-36 Lithology GR Fe Al Si Ca S Upper Bakken Middle Bakken Clastic Carbonate Pyrite Lower Bakken Clay Three Forks

11 CMR (Combinable Magnetic Resonance) Porosity and Permeability Vertical Well Lithology independent porosity and permeability Horizontal placement - used with ELAN for complete pay evaluation Combinable with other logging tools lower rig costs Good resolution of laminated sediments (Three Forks)

12 CMR - Porosity Definitions T2 Distribution - Main output of CMR 0.3ms T2 3.0ms 33ms Small Pore Porosity Capillary Bound Porosity CMFF (%) CMRP_3MS (%) TCMR (%) Free Fluid Porosity (Producible Fluids) LOG_T2CUTOFF T2 Distribution 0.3ms 3000ms 3000ms Total Porosity Area under Distribution Three porosity measurements give an indication of the types of porosity which are present.

13 CMR Nesson State 42X-36 (Vertical) Three Forks Best Ф and k developed in laminated sediments (dolomite and mudstone) at top In general better Ф and k than Bakken; more dolomite Upper Bakken Middle Bakken Lower Bakken Three Forks GR 10% 1 md k Ф Middle Bakken Best Ф and k developed in dolomitic sediments Decrease in Ф and k toward base

14 Lithology and Matrix Results - Nesson State 42X-36 Lithology (Dry Weight %) 30% Ф % k 10 md Upper Bakken Fld Qtz Ls Dol Middle Bakken Illite Pyr Lower Bakken Dol Three Forks Detailed lithology (ELAN) tied to core and ECS Porosity and permeability tied to core and CMR

15 Reservoir Saturation Tool (RST) (Reservoir Characterization) Provides low cost way of acquiring information in laterals Pumped down inside drill pipe When calibrated to core and vertical logs from pilot well can be used to determine: Calcite Lithology Porosity (reserves) Used in hydraulic fracture stage selection or swell packer placement Quartz Clay Porosity

16 Stimulation Optimization Mechanical Rock Properties Containment Planning

17 Sonic Scanner (3-D Rock Mechanical Properties) Stress orientation (SH) Stress magnitude Anisotropic mechanical rock properties Young s Modulus Poisson s Ratio Input for hydraulic fracture modeling and optimization TOC

18 Sonic Scanner - 3-D Rock Mechanics GR Upper Bakken 0.73/0.89 Large stress difference due to shale layering Middle Bakken 0.73/0.73 Young s Modulus and PR differ by 80% Lower Bakken Three Forks Young s Modulus PR Aniso Stress 0.73/0.81 In this well hydraulic fracture containment provided by Bakken Shales

19 Multi Stage Nesson State 44X-36 Fractures TXSP Aniso % Carbonate GR Stage 6 Stage 5 Stage 4 Stage 3 Stage 2 Stage 1 In Target Perforations Packer

20 Recommended Logging Suite - Vertical Vertical Pilot (first 1 to 2 wells in an area) PEx (Resistivity and Porosity) ECS (Lithology) CMR (Porosity and Permeability) RST (Reservoir Characterization) Sonic Scanner (SH and Vertical Hydraulic Fracture Containment) Core

21 Recommended Logging Suite - Laterals Lateral (first 1 to 2 wells in an area) FMI (Fracture Characterization) TVD ECS Sonic Scanner RST Lateral (Development) RST MD

22 Summary Core calibrated log measurements in the Bakken and Three Forks can lead to a better understanding of : Fractures Porosity Permeability Lithology Anisotropic mechanical rock properties and stress profile These log measurements can be used to model and optimize stimulations