The document discusses the relationship between capillary pressure curves and flow rates in reservoir analysis, highlighting the importance of saturation height functions and step-by-step workflows for defining permeability. It emphasizes understanding reservoir quality through saturation height modeling, particularly in virgin oil zones, while noting heterogeneity even in seemingly uniform reservoirs. The analysis calls for better integration of petrophysical log data to enhance insights into reservoir productivity.

1. Permeability: from Cap Curve to Flowrate Graham Davis Chief Petrophysicist

2. Overview Saturation Height Functions Understand the reservoir controls on saturation distribution Thomeer Capillary Pressure Curve Analysis The “meaningful” co-efficients Step-by-step analysis workflow From cap-curve to flow profile Where to go from here………..? lets discuss!

3. Common Sat-Height(Pc) Functions Leverett-J Sigmoidal Polynomial Exponential Hyperbola Entry Height Trig-Tangent Thomeer Lambda

4. Common Sat-Height(Pc) Functions Leverett-J Sigmoidal Polynomial Exponential Hyperbola Entry Height Trig-Tangent Thomeer Lambda

5. Thomeer Cap-Curve basics Thomeer function: Bv oil   interconnected pore volume Pe = Capillary Entry Pressure G = Pore Geometrical factor (curvature – related to Permeability) Bv oil  - 30 pu Bv oil  - 25 pu Bv oil  - 15 pu Pe = 150 G = 0.05 G = 0.25 G = 0.50 Back-Calculate G at each depth  Permeability Pe = 75 Pe = 15 Log Sw

6. a reservoir Palaeocene turbidite Porosity: 22 – 26 pu Perm: 0.4 – 1 D Phi – K crossplot Small dynamic range in Porosity

7. Petrophysical Log – Routine Log Analysis

8. Petrophysical Log – Core Data Calibration

9. Petrophysical Log – Thin Bed Analysis

10. Petrophysical Log – Linear Permeability Scales

11. Petrophysical Log – Thomeer Cap curve analysis Facies coding

12. Petrophysical Log – Thomeer Permeability (High-K Streaks) Hi-K Hi-K Hi-K Hi-K Hi-K Hi-K Hi-K Hi-K Facies coding

13. Petrophysical Log – PLT Spinner Flow Profile

14. Petrophysical Log – Differentiated Flow Profile

15. Further Examples – Linear Permeability Profile PERM SPINNER PERM SPINNER

16. Further Examples – Differentiated Flow Profile PERM SPINNER PERM SPINNER Not perfed

17. Conclusions Saturation height modelling can give “Key insights” into reservoir quality and productivity. This approach is only valid for virgin oil zones where saturation is controlled by original capillary processes rather than current production mechanisms. (Also subject to resistivity tool resolution issues.) Even apparently massively bedded reservoirs can exhibit marked heterogeneity . There is petrophysical information in PLT data – lets integrate and use more of it.

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