Methods for measuring a formation supercharge pressure

• US 20050235745A1
• Filed: 03/01/2005
• Published: 10/27/2005
• Est. Priority Date: 03/01/2004
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Wilson, Chung-Ling Chin, Proett, Mark A., Beique, Jean Michel, Welshans, David, Fogal, James M., Hardin, John R. Jr., Gray, Glenn C.
• Granted Patent: US 7,243,537 B2
• Time in Patent Office: Days
• US Class Current: 73/152.220
• CPC Class Codes: E21B 49/08 Obtaining fluid samples or testing fluids, in boreholes or wells
• CPC Class Codes: E21B 49/088 combined with sampling
• CPC Class Codes: E21B 49/10 using side-wall fluid samplers or testers

Abstract

A method of determining the supercharge pressure in a formation intersected by a borehole having a wall, the method comprising disposing a formation pressure test tool into the borehole having a probe for isolating a portion of the borehole. The method further comprises extending the probe into sealing contact with the borehole wall. The method further comprises performing at least one drawdown test with the formation pressure test tool. The method further comprises modeling the supercharge pressure of the formation using the dynamic properties of the mudcake. The method further comprises determining the supercharge pressure of the formation using the supercharge pressure model. The formation pressure test tool may be conveyed into the borehole using wireline technology or on a drill string. Using the supercharge pressure, the drawdown test may be optimized, the characteristics of the drilling fluid altered, or the measurements of other sensors adjusted.

Claims

1. A method of determining the supercharge pressure in a formation intersected by a borehole having a wall, the method comprising:

disposing a formation pressure test tool into the borehole, said formation pressure test tool having a probe for isolating a portion of the borehole;

extending said probe into sealing contact with the borehole wall;

performing at least one drawdown test with said formation pressure test tool by drawing formation fluid into a drawdown chamber of said formation pressure test tool and measuring fluid pressure in said drawdown chamber;

modeling the supercharge pressure of the formation using the dynamic properties of a mudcake on the borehole wall; and

determining the supercharge pressure of the formation using said supercharge pressure model.

2. The method of claim 1 further comprising determining the pore pressure of the formation using said supercharge pressure.

3. The method of claim 1 further comprising determining formation and mudcake properties.

4. The method of claim 1 further comprising disposing said formation pressure test tool into the borehole on a drill string.

5. The method of claim 4 further comprising modeling the supercharge pressure of the formation using pressure transient effects caused by movement of the drill string.

6. The method of claim 4 further comprising modeling the supercharge pressure of the formation using pressure transient effects caused by pressure pulses in drilling fluid in the borehole.

7. The method of claim 1 further comprising determining the supercharge pressure using a processor.

8. The method of claim 1 further comprising performing at least one leak-off test with said formation pressure test tool.

9. The method of claim 1 further comprising determining the supercharge pressure while drilling fluid is flowing in the borehole.

10. The method of claim 1 wherein extending said probe into sealing contact with the borehole wall further comprises forming seal with the borehole wall through the mudcake.

11. A method of determining the supercharge pressure in a formation intersected by a borehole having a wall, the method comprising:

disposing a formation pressure test tool into the borehole, said formation pressure test tool having a probe for isolating a portion of the borehole;

extending said probe into sealing contact with the borehole wall;

performing at least one drawdown test with said formation pressure test tool by drawing formation fluid into a drawdown chamber of said formation pressure test tool and measuring fluid pressure in said drawdown chamber;

modeling the supercharge pressure of the formation using the dynamic properties of a mudcake on the borehole wall;

determining the supercharge pressure of the formation using said supercharge pressure model; and

repeating performing drawdown tests and determining the supercharge pressure over a period of time after the borehole intersects the formation.

12. The method of claim 11 further comprising determining when to perform a formation pressure test to minimize the effect of supercharge pressure on the formation.

13. The method of claim 11 further comprising repeating determining the supercharge pressure over a period of time at the same location.

14. The method of claim 11 further comprising repeating determining the supercharge pressure over a period of time at different locations.

15. The method of claim 11 wherein extending said probe into sealing contact with the borehole wall further comprises forming seal with the borehole wall through the mudcake.

16. A method of determining the supercharge pressure in a formation intersected by a borehole having a wall, the method comprising:

disposing a formation pressure test tool into the borehole, said formation pressure test tool having a probe for isolating a portion of the borehole;

extending said probe into sealing contact with the borehole wall;

performing at least one drawdown test with said formation pressure test tool by drawing formation fluid into a drawdown chamber of said formation pressure test tool and measuring fluid pressure in said drawdown chamber;

modeling the supercharge pressure of the formation using the dynamic properties of a mudcake on the borehole wall;

determining the supercharge pressure of the formation using said supercharge pressure model; and

adjusting the properties of the drilling fluid based on the supercharge pressure.

17. The method of claim 16 further comprising adjusting the properties of the drilling fluid to minimize the supercharge pressure.

18. The method of claim 16 further comprising adjusting the chemical properties of the drilling fluid.

19. The method of claim 16 further comprising adjusting the density of the drilling fluid.

20. The method of claim 16 further comprising adjusting the drilling fluid to improve the sealing action of the mudcake.

21. The method of claim 16 further comprising adjusting the drilling fluid to increase the rate of formation of the mudcake.

22. The method of claim 16 wherein extending said probe into sealing contact with the borehole wall further comprises forming seal with the borehole wall through the mudcake.

23. A method of determining the supercharge pressure in a formation intersected by a borehole having a wall, the method comprising:

disposing a formation pressure test tool into the borehole, said formation pressure test tool having a probe for isolating a portion of the borehole;

extending said probe into sealing contact with the borehole wall;

performing at least one drawdown test with said formation pressure test tool by drawing formation fluid into a drawdown chamber of said formation pressure test tool and measuring fluid pressure in said drawdown chamber;

modeling the supercharge pressure of the formation using the dynamic properties of a mudcake on the borehole wall;

determining the supercharge pressure of the formation using said supercharge pressure model;

taking measurements with a logging while drilling sensor; and

adjusting the measurements of said logging while drilling sensor based on the supercharge pressure.

24. The method of claim 23 further comprising determining the distribution of the filtrate invasion using the supercharge pressure model.

25. The method of claim 23 wherein said logging while drilling sensor comprises an electro-magnetic wave resistivity logging sensor.

26. The method of claim 23 wherein extending said probe into sealing contact with the borehole wall further comprises forming seal with the borehole wall through the mudcake.