Wellbore formation evaluation system and method

• US 20070114021A1
• Filed: 11/21/2005
• Published: 05/24/2007
• Est. Priority Date: 11/21/2005
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: Ayers, David, Brown, Jonathan, Hlavinka, Danny
• Granted Patent: US 7,428,925 B2
• Time in Patent Office: Days
• US Class Current: 166/250.100
• CPC Class Codes: E21B 36/001 Cooling arrangements
• CPC Class Codes: E21B 47/017 Protecting measuring instruments
• CPC Class Codes: E21B 47/0175 Cooling arrangements
• CPC Class Codes: E21B 49/10 using side-wall fluid samplers or testers

Abstract

A formation evaluation tool positionable in a wellbore penetrating a subterranean formation is provided. The formation evaluation tool includes a cooling system adapted to pass a cooling fluid near electronics in the formation evaluation tool whereby heat is dissipated therefrom, the electronics has at least one gauge, a fluid communication device having an inlet adapted to receive the formation fluid and a flowline operatively connected to the fluid communication device and the gauge for placing the formation fluid in fluid communication therewith whereby properties of the formation fluid are determined. The formation evaluation tool may also be provided with a plurality of sample chambers operatively connected to the flowline for collecting at least a portion of the formation fluid and a pressure compensator in fluid communication with the wellbore and operatively connected to the plurality of sample chambers for applying pressure to the sample chambers whereby pressure is balanced therebetween.

Claims

1. A formation evaluation tool positionable in a wellbore penetrating a subterranean formation, comprising:

a cooling system adapted to pass a cooling fluid near electronics in the formation evaluation tool whereby heat is dissipated therefrom, the electronics comprising at least one gauge;

a fluid communication device having an inlet adapted to receive the formation fluid; and

a flowline operatively connected to the fluid communication device and the at least one gauge for placing the formation fluid in fluid communication therewith whereby properties of the formation fluid are determined.

2. The formation evaluation tool of claim 1, further comprising at least one sample chamber operatively connected to the flowline.

3. The formation evaluation tool of claim 2, further comprising a dump chamber operatively connected to the flowline.

4. The formation evaluation tool of claim 2 further comprising a pressure chamber having a fluid therein, the pressure chamber in fluid communication with the at least one sample chamber for applying a pressure thereto.

5. The formation evaluation tool of claim 2 further comprising a pressure compensator operatively connected to the at least one sample chamber and in selective fluid communication with the wellbore for balancing a pressure therein with a pressure in the sample chamber.

6. The formation evaluation tool of claim 2 further comprising a pressure compensator operatively connected to the at least one sample chamber and in fluid communication with the wellbore for balancing a pressure therein with a pressure in the sample chamber.

7. The formation evaluation tool of claim 6 wherein the pressure compensator comprises a chamber having a movable piston and a stationary piston therein, the movable piston slidably movable therein and defining a first variable cavity and a second variable cavity, the stationary piston separating the second variable cavity from a third fixed cavity.

8. The formation evaluation tool of claim 1 wherein the cooling system comprises a Stirling cooler and a cooling flowline, the cooling flowline adapted to conduct the cooling fluid.

9. The formation evaluation tool of claim 8 wherein the cooling system further comprises a pump operatively connected to the Stirling cooler and driven thereby, the pump adapted to pump the cooling fluid through the flowline.

10. The formation evaluation tool of claim 1 wherein the electronics are positioned in a Dewar flask.

11. The formation evaluation tool of claim 1 further comprising a buffer fluid positioned in the flowline between the formation fluid and the at least one gauge.

12. A formation evaluation tool positionable in a wellbore penetrating a subterranean formation, comprising:

a fluid communication device having an inlet adapted to receive a formation fluid;

a flowline operatively connected to the fluid communication device;

a plurality of sample chambers operatively connected to the flowline for collecting at least a portion of the formation fluid; and

a pressure compensator in fluid communication with the wellbore and operatively connected to the plurality of sample chambers for applying pressure to the sample chambers whereby pressure is balanced therebetween.

13. The formation evaluation tool of claim 12 wherein each sample chamber has a piston slidably movable therein, the pistons defining a sample cavity for receiving formation fluid and a buffer cavity in fluid communication with the pressure compensator.

14. The formation evaluation tool of claim 12 wherein the buffer cavities of each sample chamber are in fluid communication with each other.

15. The formation evaluation tool of claim 12 wherein the pressure compensator has a movable piston slidably positionable therein, the movable piston defining a first cavity in fluid communication with the buffer cavities and a second cavity in selective fluid communication with the wellbore.

16. The formation evaluation tool of claim 12 wherein the pressure compensator has a movable piston slidably positionable therein, the movable piston defining a first cavity in fluid communication with the buffer cavities and a second cavity in fluid communication with the wellbore.

17. The formation evaluation tool of claim 16 wherein the pressure compensator has a stationary piston therein separating the second cavity from a third cavity, a rod of the movable piston slidably positionable in the stationary piston, the stationary piston and the rod of the movable piston defining a fourth cavity.

18. The formation evaluation tool of claim 17 wherein the fourth cavity is in selective fluid communication with the third cavity for selectively releasing pressure therein.

19. The formation evaluation tool of claim 17 wherein the fourth cavity is in fluid communication with the third cavity for releasing pressure therefrom.

20. The formation evaluation tool of claim 12 further comprising a cooling system adapted to pass a cooling fluid near electronics in the formation evaluation tool whereby the electronics are cooled.

21. The formation evaluation tool of claim 20 wherein the cooling system comprises a Stirling cooler and a cooling flowline, the cooling flowline adapted to conduct the cooling fluid.

22. The formation evaluation tool of claim 21 wherein the cooling system further comprises a pump operatively connected to the Stirling cooler and driven thereby, the pump adapted to pump the cooling fluid through the flowline.

23. The formation evaluation tool of claim 20 wherein the electronics are positioned in a Dewar flask.

24. The formation evaluation tool of claim 20 wherein the electronics comprises at least one gauge.

25. The formation evaluation tool of claim 24 wherein the flowline is operatively connected to the at least one gauge whereby properties of the formation fluid are determined.

26. A method of performing formation evaluation via a downhole tool positioned in a wellbore penetrating a subterranean formation, comprising:

removing heat from electronics in the downhole tool by passing a cooling fluid near the electronics, the electronics comprising at least one gauge;

establishing fluid communication between a fluid communication device and the formation, the fluid communication device having an inlet adapted to receive a formation fluid from the formation;

establishing fluid communication between the inlet and the at least one gauge via a flowline; and

measuring at least one parameter of the formation fluid via the gauge.

27. The method of claim 26 further comprising positioning a buffer fluid in the flowline between the formation fluid and the gauge.

28. The method of claim 26 further comprising passing at least a portion of the formation fluid into a plurality of sample chambers, each of the plurality of sample chambers having a movable piston slidably positioned therein, the movable piston defining a sample cavity and a buffer cavity.

29. The method of claim 28 further comprising applying a pressure to the buffer cavities.

30. The method of claim 28 further comprising establishing fluid communication between the wellbore and a wellbore cavity of a pressure compensator and balancing the pressure between the buffer cavities and the wellbore cavity.

31. The method of claim 28 further comprising establishing selective fluid communication between the wellbore and a wellbore cavity of a pressure compensator and balancing the pressure between the buffer cavities and the wellbore cavity.

32. The method of claim 26 wherein the step of removing heat comprises removing heat from electronics in a downhole tool by magnetically reciprocating a pump to drive cooling fluid through a cooling flowline positioned adjacent electronics in the downhole tool, the electronics comprising at least one gauge.

33. A method of performing formation evaluation via a downhole tool positioned in a wellbore penetrating a subterranean formation, comprising:

establishing fluid communication between a fluid communication device and the formation, the fluid communication device having an inlet adapted to receive a formation fluid from the formation;

drawing formation fluid through the inlet and into a plurality of sample chambers via a flowline, each of the plurality of sample chambers having a movable piston slidably positioned therein, the movable piston defining a variable volume sample cavity and a variable volume buffer cavity, the variable volume sample cavity adapted to receive the formation fluid;

establishing fluid communication between a wellbore cavity of a pressure compensator and the wellbore; and

balancing the pressure between the variable volume buffer cavities and the wellbore cavity.

34. The method of claim 33 wherein the step of establishing fluid communication between a wellbore cavity comprises establishing selective fluid communication between a wellbore cavity of a pressure compensator and the wellbore.

35. The method of claim 33 further comprising passing at least a portion of the formation fluid into at least one dump chamber.

36. The method of claim 33 further comprising measuring at least one parameter of the formation fluid via at least one gauge.

37. The method of claim 36 further comprising positioning a buffer fluid in a flowline extending from the inlet to the at least one gauge.

38. The method of claim 36 further comprising cooling the gauge by passing a cooling fluid near the gauge.