Method and apparatus for downhole fluid analysis using molecularly imprinted polymers

• US 7,395,704 B2
• Filed: 11/22/2004
• Issued: 07/08/2008
• Est. Priority Date: 11/21/2003
• Status: Expired due to Fees

• Current Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: DiFoggio, Rocco
• Primary Examiner(s): Williams; Hezron E.
• Assistant Examiner(s): FITZGERALD, JOHN P
• Application Number:
  US10/994,579
• Publication Number:
  US 20050109098A1
• Time in Patent Office: 1,324 Days
• Field of Search: 731/524.2, 731/521.8, 731/525.5
• US Class Current: 73/152.42
• CPC Class Codes: E21B 49/10 using side-wall fluid samplers or testers

Abstract

The present invention provides a downhole method and apparatus using molecularly imprinted polymers to analyze a downhole fluid sample or determine the percentage of oil based mud filtrate contamination in a formation fluid sample.

Claims

1. An apparatus for estimating a property of a gas diffused from a downhole fluid comprising:

a flow line receiving the downhole fluid;

a chamber receiving the downhole fluid from the flow line;

a pump evacuating the chamber;

an analyte selective sensor in communication with the gas diffused from the downhole fluid in the chamber; and

a processor that uses a characteristic of the sensor to estimate the property of the gas diffused from the downhole fluid.

2. The apparatus of claim 1, wherein the analyte selective sensor is a molecularly imprinted polymer (MIP) sensor.

3. apparatus of claim 1, further comprising:

a gas permeable membrane positioned in the chamber.

4. The apparatus of claim 1, wherein the sensor adsorbs an analyte associated with the gas diffused from the downhole fluid.

5. The apparatus of claim 1, further comprising:

a desorber that substantially removes an adsorbed analyte from the sensor.

6. The apparatus of claim 1, further comprising:

at least one of the set consisting of;

(i) a heater and;

(ii) a flushing fluid to cause the sensor to desorb an absorbed analyte.

7. The apparatus of claim 1, wherein the response from the sensor comprises at least one of the set consisting of a luminescence, resistance, fluorescence, an electrical characteristic and light leakage.

8. The apparatus of claim 1, wherein the processor estimates at least one of compartmentalization and filtrate fraction using the property of the gas diffused from the downhole fluid.

9. The apparatus of claim 1, wherein the processor uses a neural network.

10. The apparatus of claim 1 further comprising:

a membrane diffusing the gas from the downhole fluid and being supported from a downhole pressure by one of (i) a porous member, and (ii) a permeable member.

11. The apparatus of claim 1 further comprising:

a membrane diffusing the gas from the downhole fluid and dividing the chamber into a first chamber receiving the downhole fluid and a second chamber receiving the diffused gas.

12. The apparatus of claim 11 the pump is an ion pump.

13. A method for estimating a property of a gas diffused from a downhole fluid, comprising:

flowing the downhole fluid through a flow line;

evacuating a chamber in communication with the flow line to cause a vacuum pressure in the chamber;

receiving the downhole fluid from the flow line into the chamber;

exposing an analyte selective sensor in the chamber to the gas diffused from the down hole fluid; and

estimating the property of the gas diffused from the downhole fluid based on a response associated with the sensor.

14. The method of claim 13, wherein the sensor comprises a molecularly imprinted polymer (MIP) sensor.

15. The method of claim 13, wherein the exposing comprises:

positioning a gas permeable membrane in the chamber; and

diffusing the gas from the downhole fluid through the gas permeable-membrane.

16. The method of claim 13, wherein exposing further comprises

sorbing on the sensor an analyte associated with the gas diffused from the downhole fluid.

17. The method of claim 13, further comprising:

desorbing an adsorbed analyte from the sensor.

18. The method of claim 13, further comprising:

at least one of heating and flushing the sensor to desorb an adsorbed analyte from the sensor.

19. The method of claim 13, wherein the response associated with the sensor comprises at least one of the set consisting of a luminescence, resistance, an electrical characteristic fluorescence and light leakage.

20. The method of claim 13, further comprising:

estimating at least one of the set consisting of compartmentalization and filtrate fraction using the property of the gas diffused from the downhole fluid.

21. The method of claim 13, wherein the estimating comprises at least one of the set consisting of using a chemometric equation and neural network to estimate the property of the gas diffused from the downhole fluid.

22. The method of claim 13 further comprising:

diffusing the gas from the downhole fluid through a membrane supported from a downhole pressure by one of (i) a porous member, and (ii) a permeable member.

23. The method of claim 13 further comprising:

dividing the chamber into a first chamber receiving the downhole fluid and a second chamber receiving the diffused gas with a membrane; and

diffusing the gas from the downhole fluid through the membrane.

24. The method of claim 23 further comprising:

evacuating the second chamber with an ion pump.

25. A system for estimating a property of a gas diffused from a downhole fluid comprising a bore transecting a zone containing the down hole fluid;

a wireline conveyed downhole tool;

a flow line associated with the downhole tool, the flow line receiving the downhole fluid pumped from the formation;

a chamber receiving the downhole fluid from the flow line;

a pump configured to evacuate the chamber and create a vacuum pressure in the chamber;

an analyte specific sensor associated with the gas diffused from the down hole fluid; and

a processor that uses a response associated with the sensor and estimates the property of the gas diffused from the downhole fluid.

26. The system of claim 25, wherein the analyte specific sensor is a molecularly imprinted polymer (MIP) sensor.

27. The system of claim 25, further comprising:

a gas permeable membrane in the chamber.

28. The system of claim 25, wherein the sensor adsorbs an analyte associated with the gas diffused from the downhole fluid.

29. The system of claim 25, further comprising:

a desorber that substantially removes an adsorbed analyte from the sensor.

30. The system of claim 25, further comprising:

at least one of a heater or a flushing fluid that substantially desorbs an adsorbed analyte from the sensor.

31. The system of claim 25, wherein the response from the sensor comprises at least one of the set consisting of a luminescence, resistance, fluorescence, an electrical characteristic and light leakage.

32. The system of claim 25, wherein the processor estimates at least one compartmentalization and filtrate fraction using the property of the gas diffused from the downhole fluid.

33. The system of claim 25, wherein the processor comprises a neural network to estimate the property of the gas diffused from the downhole fluid.

34. The system of claim 25 further comprising:

a membrane diffusing the gas from the downhole fluid and being supported from a downhole pressure by one of (i) a porous member, and (ii) a permeable member.

35. The system of claim 25 further comprising:

a membrane diffusing the gas from the downhole fluid and dividing the chamber into a first chamber receiving the downhole fluid and a second chamber receiving the diffused gas.

36. The system of claim 35 the pump is an ion pump.