1. Pore-Scale Analysis of WAG Flooding V. Sander Suicmez Dr. Mohammad Piri Prof. Martin J. Blunt 5 Jan 2005 Centre for Petroleum Studies Department of Earth Science and Engineering Imperial College London

2. Outline  Introduction  What has already been done? Two- and three-phase pore-scale configurations  Two- and three-phase pore-scale configurations  Displacement mechanisms  Validation - comparison with experimental data  What is new?  New displacement mechanisms  More complicated saturation paths  A generic WAG study  Conclusions & Future Work

3. Introduction

4. What do we have? Piri, 2003 A three-phase flow simulator (incorporating geologically  A three-phase flow simulator (incorporating geologically realistic network model) with full extension of possible realistic network model) with full extension of possible generic configurations for any wettability. generic configurations for any wettability.  A robust clustering algorithm incorporating coalescence and break of trapped clusters. and break of trapped clusters.  Point-by-point comparison with data using saturation path tracking algorithm. path tracking algorithm.

5. One- and Two-Phase ConfigurationsWaterOil Gas

6. Three-PhaseConfigurationsWaterOil Gas

7. Example Displacement Sequence Configuration B Configuration A Configuration B Configuration A Configuration C Primary DrainageWater Flooding Gas Injection Configuration F Layer Collapsing Gas Injection Gas Water Oil

8. Saturation Tracking Oak data, Piri, 2003 Measured and tracked saturation paths

9. Oil Relative Permeability Piri, 2003

10. Gas Relative Permeability Piri, 2003

11. Water Relative Permeability Piri, 2003

12. Simultaneous Gas & Water Injection

13. Oil Relative Permeability

14. Water Relative Permeability

15. Gas Relative Permeability

16. Mobilising Oil by Double Displacement WaterOil Gas Trapped Oil

17. Double Displacements Gas Injection Gas Oil Water Gas Water Oil Water Injection Water Oil Gas Water Gas Oil Oil Injection Oil Gas Water Oil Water Gas

18. Multiple displacements in WAG Sorbie & van Dijke, 2001

19. A Generic WAG Study Spreading Oil Layers Weakly Water Wet (Oak’ s data)

20. WAG study

21. Oil Reconnection

22. Gas Relative Permeability

23. Pore Occupancy

25. Water Relative Permeability

26. Pore Occupancy

27. Experimental k rg Element et al. 2003

28. Comparison

29. Conclusions Water first invades the smaller throats at the dead-ends which does not change the gas relative permeability With snap-off process gas phase gets trapped There is a significant number of Double Displacement events Multiple Displacement is not required. However wettability conditions, spreading coefficients and saturation paths may change the situation

30. Future Work Debugging the code!!! Predicting the relative permeability behaviour of WAG process for different wettability conditions. Quantitative match with experimental data Come up with a new empirical three phase relative permeability model

31. Acknowledgments  Shell  Schlumberger  Statoil  BHP  BG  Saudi Aramco  Eni  Total  Japan National Oil Corporation (JNOC)  Department of Trade and Industry (DTI)  EPSRC We are thankful to the members of the Imperial College Consortium on Pore-Scale Modelling for their generous and continued support to our research: