FORMATION EVALUATION SYSTEM AND METHOD

• US 20090101339A1
• Filed: 12/19/2008
• Published: 04/23/2009
• Est. Priority Date: 06/28/2002
• Status: Active Grant

• Current Assignee: Alexander F. Zazovsky, Christopher S. Del Campo, Ricardo Vasques
• Original Assignee: Alexander F. Zazovsky, Christopher S. Del Campo, Ricardo Vasques
• Inventors: Vasques, Ricardo, Del Campo, Christopher S., Zazovsky, Alexander F.
• Granted Patent: US 8,047,286 B2
• Time in Patent Office: Days
• US Class Current: 166/250.10
• CPC Class Codes: E21B 49/10 using side-wall fluid samplers or testers

Abstract

A method of evaluating a fluid from a subterranean formation drawn into a downhole tool positioned in a wellbore penetrating the subterranean formation is provided. The method involves drawing fluid from a formation into an evaluation flowline, drawing fluid from a formation into a cleanup flowline, measuring a property of the fluid in the evaluation flowline and detecting stabilization of the property of the fluid in the evaluation flowline. Fluid properties in a combined flowline may be generated from the evaluation and cleanup flowlines. The fluid properties of the combined flowline may be used to project future evaluation flowline fluid properties. Contamination levels for a given fluid property of a given flowline may also be determined.

Claims

1. A downhole tool, comprising:

a probe comprising;

a first inlet having an elongated cross-sectional shape; and

a second inlet surrounding the first inlet; and

at least one pump configured to draw fluid from a subterranean formation through the first and second inlets.

2. The downhole tool of claim 1 wherein the cross-sectional shape of the first inlet is essentially oval.

3. The downhole tool of claim 1 wherein the at least one pump is configured to draw contaminated fluid through the second inlet and virgin fluid through the first inlet.

4. The downhole tool of claim 1 wherein the probe further comprises an elastomeric portion surrounding the second inlet and configured to be extended into sealing engagement with a wellbore wall.

5. The downhole tool of claim 1 wherein the probe further comprises a wall interposing the first and second inlets.

6. The downhole tool of claim 5 wherein the wall fluidly isolates the first and second inlets

7. The downhole tool of claim 5 wherein the wall selectively fluidly isolates the first and second inlets

8. The downhole tool of claim 5 wherein the probe further comprises an elastomeric portion surrounding the second inlet and configured to be extended into sealing engagement with a wall of a wellbore extending through the subterranean formation, and wherein a distal end of the probe wall is recessed a distance within the elastomeric portion.

9. The downhole tool of claim 5 wherein the probe further comprises an elastomeric portion surrounding the second inlet and configured to be extended into sealing engagement with a wall of a wellbore extending through the subterranean formation, and wherein a distal end of the probe wall is selectively positionable flush with an outer surface of the elastomeric portion.

10. The downhole tool of claim 5 wherein the wall comprises at least one of a slidable collar, a pleated tube, a plurality of bellows, an elastomeric ring, and an elastomeric tube.

11. The downhole tool of claim 1 further comprising:

a first flow line in fluid communication with the first inlet; and

a second flow line in fluid communication with the second inlet, wherein the at least one pump is configured to draw fluid from the subterranean formation through the first and second inlets into the first and second flow lines, respectively.

12. The downhole tool of claim 1 further comprising a sample chamber selectively connected to the first inlet.

13. The downhole tool of claim 1 wherein the downhole tool is a wireline tool.

14. The downhole tool of claim 1 wherein the downhole tool is a logging while drilling tool.

15. A method of sampling fluid from a subterranean formation, comprising:

positioning a downhole tool in a wellbore adjacent the subterranean formation, the downhole tool comprising;

a probe comprising;

a first inlet having an elongated cross-sectional shape; and

a second inlet surrounding the first inlet; and

at least one pump configured to draw fluid from the subterranean formation through the first and second inlets;

positioning the probe in fluid communication with the subterranean formation; and

operating the at least one pump to draw fluid from the subterranean formation through the first and second inlets.

16. The method of claim 15 wherein drawing fluid from the subterranean formation comprises drawing virgin fluid from the subterranean formation through the first inlet and drawing contaminated fluid from the subterranean formation through the second inlet.

17. The method of claim 15 further comprising adjusting separation of virgin fluid into the first inlet and contaminated fluid into the second inlet by controlling a flow rate of fluid through the first and second inlets.

18. The method of claim 15 further comprising adjusting separation of virgin fluid into the first inlet and contaminated fluid into the second inlet by positioning the first inlet relative to the second inlet.

19. The method of claim 15 further comprising adjusting separation of virgin fluid into the first inlet and contaminated fluid into the second inlet by adjusting operation of the at least one pump.

20. The method of claim 19 wherein the at least one pump comprises a first pump configured to draw fluid from the subterranean formation through the first inlet and a second pump configured to draw fluid from the subterranean formation through the second inlet, and wherein adjusting operation of the at least one pump comprises adjusting relative flow rates of the first and second pumps.

21. The method of claim 15 further comprising monitoring a parameter of formation fluid drawn through the first inlet.

22. The method of claim 15 further comprising detecting whether formation fluid drawn through the first inlet is virgin fluid.

23. The method of claim 22 wherein detecting comprises identifying a plateau on a signature of a monitored parameter.

24. The method of claim 15 further comprising adjusting a flow rate ratio of fluid drawn through the first and second inlets.

25. The method of claim 24 further comprising identifying two or more plateaus on a signature of a monitored parameter of fluid drawn through the first inlet.

26. The method of claim 15 further comprising selectively positioning the first inlet flush with an outer surface of an elastomeric portion of the probe, wherein the elastomeric portion surrounds the second inlet.

27. The method of claim 15 further comprising equalizing a first pressure within the first inlet relative to a second pressure within the second inlet.

28. The method of claim 27 wherein equalizing comprises adjusting a recess distance of the first inlet within the probe.

29. The method of claim 15 further comprising capturing a sample in a sample chamber fluidly connected to the first inlet.

30. The method of claim 15 wherein positioning the downhole tool in the wellbore is performed using a wireline cable.

31. The method of claim 15 wherein positioning the downhole tool in the wellbore is performed using a drill string.