1. HEAVY-OIL SEISMIC MONITORING at PIKES PEAK, SK I.A. Watson*, L.R. Lines and K.F. Brittle November 20, 2001

2. Combined two CREWES papers Combined two CREWES papers – “Heavy-oil time-lapse seismic monitoring at Pikes Peak, Saskatchewan” – “Heavy-oil reservoir characterization using elastic wave properties”

3. Outline Introduction Introduction Geology Geology Analysis 1: Section Differencing Analysis 1: Section Differencing Analysis 2: Isochron Ratio Analysis 2: Isochron Ratio Analysis 3: Vp/Vs Ratio Analysis 3: Vp/Vs Ratio Conclusions Conclusions

4. Pikes Peak Time-lapse Injected steam Injected steam – Reduces reservoir impedance – Causes increased compressional wave traveltime Two (time-lapse) seismic lines Two (time-lapse) seismic lines – 2-D lines in co-incident locations 1991 (swath) 1991 (swath) 2000 (multi-component) 2000 (multi-component)

5. Pikes Peak Heavy-oil field Heavy-oil field Operated by Husky Energy Operated by Husky Energy 40 km east of Lloydminster 40 km east of Lloydminster Over 40 million bbls produced Over 40 million bbls produced Steam injection operation Steam injection operation

6. DATA 200+ wells 200+ wells 1991 2D swath 1991 2D swath 2000 4C-2D 2000 4C-2D 2000 VSP 2000 VSP Pikes Peak Field Map

7. Data Comparison H1991 February 1991 6 sec 8-110 Hz non-linear 3 vibrators over 20 m 4 sweeps/vp 10 m drag length 40 m source interval 20 m group interval 9 geophones over 20 m 30 CDP fold Bandwidth 14 – 110 Hz H2000 March 2000 16 sec 8-150 Hz non-linear 2 vibrators over 20 m 4 sweeps/vp No drag 20 m source interval 20 m group interval 6 geophones over 10 m 66 CDP fold Bandwidth 14 – 150 Hz

8. Data Comparison

9. Pikes Peak Geology Waseca Trend in Pikes Peak Area Van Hulten, 1984

10. Pikes Peak Geology Incised valley Incised valley Estuarine -point bars Estuarine -point bars N-S N-S ~500 m depth ~500 m depth Salt dissolution structure Salt dissolution structure and stratigraphic trap and stratigraphic trap 80-90% oil saturation 80-90% oil saturation 5-30 m net pay 5-30 m net pay 32-36% porosity 32-36% porosity 1-10 darcies perm. 1-10 darcies perm. 12° API 12° API Van Hulten, 1984

11. Analysis 1: Section Differencing Time-lapse differences of Time-lapse differences of – Reflectivity – Acoustic Impedance (AI)

12. Calibration Required prior to differencing Required prior to differencing Hampson-Russell’s Pro4D Hampson-Russell’s Pro4D Adjustments for: Adjustments for: Time Time Amplitude Amplitude Phase Phase Time window above zone of interest Time window above zone of interest Trace-by-trace gave best results Trace-by-trace gave best results

13. Refectivity Differencing Applied a wavelet-shaping filter to H2000 Applied a wavelet-shaping filter to H2000 Differences seen below reservoir Differences seen below reservoir Increase in traveltime caused by presence of injected steam Increase in traveltime caused by presence of injected steam Does not allow signal to cancel Does not allow signal to cancel Other differences Other differences Noise Noise Acquisition parameters Acquisition parameters

14. H1991 Reflectivity Section NS

15. H2000 Reflectivity Section

16. Reflectivity Difference Section

17. Impedance Differencing Applied a band-pass filter, wavelet shaping and time and phase matching to H2000 Applied a band-pass filter, wavelet shaping and time and phase matching to H2000 Significant differences seen within reservoir zone – lower impedance Significant differences seen within reservoir zone – lower impedance Lower AI extends further than expected Lower AI extends further than expected Has the steam reached further? Has the steam reached further? Limited by 2-D section Limited by 2-D section

18. H1991 AI Section

19. H2000 AI Section

20. AI Difference Section

21. Analysis 2: Isochron Ratio Interpretation based Interpretation based – H1991 and H2000 – Waseca-Sparky interval

22. Isochron ratio Addition of steam Addition of steam – Vp decrease – Increase in 2000/1991 isochron ratio Position of steam zone predicted on line Position of steam zone predicted on line Seismic line Steam zone on line Steam zone radius Husky, 2000

23. D2-6 Waseca Core Analysis 0 500 1000 1500 2000 2500 020406080100120140160180 Temperature (°C) Velocity (m/s) Compressional Source: Core Laboratories

24. H1991 Reflectivity Section

25. H2000 Reflectivity Section

26. 2000/1991 P-P Isochron Ratio (Waseca-Sparky)

27. Analysis 3: Vp/Vs Ratio Interpretation based Interpretation based – H2000 multi-component only – PP and PS sections – 2 intervals

28. Vp/Vs ratio Addition of steam Addition of steam – Vs decrease < Vp decrease –  Vp/Vs decrease = steamed zone Vp/Vs ratio derived from P-P and P-S interpretations Vp/Vs ratio derived from P-P and P-S interpretations Margrave et al., 1998

29. D2-6 Waseca Core Analysis 0 500 1000 1500 2000 2500 020406080100120140160180 Temperature (°C) Velocity (m/s) Shear Compressional Source: Core Laboratories

30. H2000 P-P (Vertical Component)

31. H2000 P-S (Radial Component)

32. Vp/Vs Isochron Ratio (Waseca-Sparky)

33. Vp/Vs Isochron Ratio (Mnvl to L.Mnvl)

34. Conclusions Anomalies are generally located where expected Anomalies are generally located where expected Inferred steam response on both the time- lapse and the Vp/Vs ratio plots Inferred steam response on both the time- lapse and the Vp/Vs ratio plots Difficult interpretation on converted wave data Difficult interpretation on converted wave data Potential lateral lithology changes identified Potential lateral lithology changes identified Minimize all variables external to the reservoir Minimize all variables external to the reservoir 3-D seismic data is recommended 3-D seismic data is recommended

35. Acknowledgements Husky Energy Husky Energy AOSTRA (COURSE) AOSTRA (COURSE) Jason Geosystems Jason Geosystems Hampson-Russell Hampson-Russell CREWES CREWES NSERC and Imperial Oil NSERC and Imperial Oil

37. PS synthetic: GMA

38. Acoustic Impedance ( AI ) AI obtained through inversion AI obtained through inversion Band limited result Band limited result Trace-based vs. model-based Trace-based vs. model-based Post-stack interpretation technique Post-stack interpretation technique McQuillin 1984

39. AI Inversion Reduces effect of wavelet sidelopes and tuning Reduces effect of wavelet sidelopes and tuning Interpret boundaries and evaluate internal properties Interpret boundaries and evaluate internal properties Allows direct comparison of time-lapse surveys Allows direct comparison of time-lapse surveys Inversion performed using Jason Geoscience Inversion performed using Jason Geoscience

40. Well Months before H91 Months before H00 3B1-6014 1D2-63825 3C1-66789 3B8-6n/a0 2B9-6n/a26 1D10-6n/a12 Injection Information

41. PS synthetic: matlab 0 300