1. Stimulation

2. Fracture Damage Increasing Fracture Pressure RII Gained Injection Area
Date
RII
Increasing Fracture Pressure
Gained Injection Area

3. Fracture Damage Fracture Plugging and Ballooning Fracture Plugged RII
Date
RII
Fracture Plugging and Ballooning
Fracture Growth
Fracture Plugged

4. Existing Fracture

5. Solid Deposition

6. Fracture Growth

7. Fracture Plugged

8. Determining Slope RII f(temperature, damage, pore pressure)
f(fracture pressure)
Date

9. Determining Slope
F(Water Quality)
RII
F(Fracture Pressure)
Date

10. Mechanism Blue lines Red lines Top line - fracturing pressure
Bottom line - gain area from fracture
Red lines
Positive gradient - matrix (stationary fracture) injection
Drop caused by the gain in area

11. Stimulation Flag Frac. Pressure line intersects Gain: Stimulation:
Fracture completely filled
Dramatic rise in pressure
Stimulation:
Establish trend
Predict Intersection
Stimulate in advance

12. RII vs. Date Progressive Increase in the plugging slope
Phillips Chalk Field

13. RII vs. Cumulative Injection
Increasing
Fracture
Pressure
Maersk A Field

14. Modes of Injection Maersk A Field Red - Fracture Blue - Stationary
Yellow - Plugged
Maersk A Field

15. Modes of Injection Increasing Fracture Pressure Maersk A Field
Red - Fracture
Blue - Stationary
Fracture
Yellow - Plugged
Increasing Fracture
Pressure
Maersk A Field

16. Modes of Injection Strong correlation from previous 2 plots
Change of injection mode between fracturing & matrix

17. Sandstone Example
Constant
Fracture
Pressure
BP PB Unit

18. Correlation with PEA 23 PB Unit
PB Unit the gradient of bounding lines = 0
Both mechanisms work together to create relatively constant RII
Both theories seem to correlate well

19. Correlation with PEA 23 Maersk A Field
Account for increasing fracture pressure
Recalculate RII with increasing F.P.
Should see constant RII

20. RII From Fracture Pressure
Maintained
Injection
Maersk A Field

21. Side Benefit Predict/Estimate - Fracture pressure
Correlate to Step Rate Test

22. Stimulation Evaluation
RII
RII
Baseline
Date

23. Definition Baseline - best performance RII - current performance
Stimulation - commonly acidizing

24. Stimulation Evaluation
Slope Before
RII
DRII Before
Date

25. Stimulation Evaluation
Slope After
RII
DRII After
Date

26. Factors
DRII - measure of damage
Slope - rate of damage accumulation

27. Example
Elf Field 3

28. Example 2
Maersk Field A

29. Hall Plot Examination Improvement Ratio RII Field Data Ideal Case
Stimulation
Date

30. Ideal Hall Plot
Ideal or initial injectivity immediately following stimulation

31. Improvement Ratio
Shows the gain in injectivity

32. Hall Plot
Elf Field 3

33. Hall Plot
Maersk Field A