Downhole cooling based on thermo-tunneling of electrons

• US 20060213660A1
• Filed: 03/23/2005
• Published: 09/28/2006
• Est. Priority Date: 03/23/2005
• Status: Active Grant

• Current Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: DiFoggio, Rocco, Shipley, Frederick E.
• Granted Patent: US 7,571,770 B2
• Time in Patent Office: Days
• US Class Current: 166/254.200
• CPC Class Codes: E21B 47/013 Devices specially adapted for supporting measuring instruments on drill bits
• CPC Class Codes: E21B 47/017 Protecting measuring instruments
• CPC Class Codes: E21B 47/0175 Cooling arrangements

Abstract

An apparatus for and a method of cooling electronic components in downhole equipment using the principles of quantum tunneling.

Claims

1. An apparatus for cooling electronic components in a borehole, the apparatus comprising:

(a) a quantum thermocooler which maintains downhole electronic components below a predefined temperature.

2. The apparatus of claim 31 wherein the downhole assembly further comprises a bottomhole assembly (BHA) including a drillbit.

3. The apparatus of claim 31 wherein the downhole assembly further comprises a string of logging instruments.

4. The apparatus of claim 31 wherein the downhole assembly includes at least one formation evaluation (FE) sensor selected from the group consisting of (i) a gamma ray sensor, (ii) a resistivity sensor, (iii) a nuclear magnetic resonance sensor.

5. The apparatus of claim 31 wherein the downhole assembly includes a processor which determines from an output of at least one formation evaluation (FE) sensor a parameter of interest of the earth formation.

6. The apparatus of claim 1 wherein the predefined temperature is less than about 200°

C.

7. The apparatus of claim 1 wherein the quantum thermocooler comprises an emitter and a collector spaced apart by a distance less than about 20 nm.

8. The apparatus of claim 1 further comprising a Dewar flask which substantially encloses the electronic components.

9. The apparatus of claim 8 further comprising a phase change material within the Dewar flask, the phase change material facilitating maintaining the electronic components below the predefined temperature.

10. The apparatus of claim 1 further comprising thermal fins that enable the quantum thermocooler to convey heat from the electronic components to a fluid in the borehole.

11. The apparatus of claim 2 further comprising at least one FE sensor on the drill bit.

12. The apparatus of claim 11 wherein the sensor on the drillbit comprises a resistivity sensor.

13. The apparatus of claim 4 wherein the at least one FE sensor comprises a nuclear magnetic resonance sensor including a trapped field magnet.

14. The apparatus of claim 5 wherein the parameter of interest is selected from the group consisting of (i) a horizontal resistivity of the formation, (ii) a vertical resistivity of the formation, (iii) a positions of an interface in the formation, (iv) a clay bound water of the formation, (v) bound volume irreducible, and (vi) porosity.

31. The apparatus of claim 1 further comprising a downhole assembly including the electronic components wherein the electronic components are substantially inoperable above the predefined temperature.

15. A method of evaluating an earth formation, the method comprising:

(a) conveying a downhole assembly including electronic components into a borehole;

(b) cooling the electronic components using a quantum thermocooler; and

(c) using the electronic components to evaluate the earth formation.

16. The method of claim 15 wherein the downhole assembly further comprises a bottomhole assembly (BHA) including a drill bit, the method further comprising conveying the BRA on a drilling tubular.

17. The method of claim 15 wherein the downhole assembly includes at least one formation evaluation (FE) sensor which makes a measurement of a parameter of interest of the earth formation.

18. The method of claim 17 wherein the downhole assembly further comprises a string of logging instruments conveyed on a wireline.

19. The method of claim 17 wherein the at least one (FE) sensor is selected from the group consisting of (i) a gamma ray sensor, (ii) a resistivity sensor, (iii) a nuclear magnetic resonance tool.

20. The method of claim 17 further comprising determining from an output of the at least one FE sensor the parameter of interest of the earth formation.

21. The method of claim 15 further comprising maintaining the electronic components at a temperature less than about 200°

C.

22. The method of claim 15 further comprising positioning an emitter and a collector of the quantum thermocooler by a distance less than about 20 nm.

23. The method of claim 15 further comprising enclosing the electronic components in a Dewar flask

24. The method of claim 23 further comprising using a phase change material within the Dewar flask for maintaining the electronic circuitry below the predefined temperature.

25. The method of claim 15 further comprising using thermal fins for enabling the quantum thermocooler to convey heat to a fluid in the borehole.

26. The method of claim 16 wherein the at least one FE sensor further comprises a resistivity sensor on the drill bit.

27. The method of claim 19 further comprising using the quantum cooler for cooling a trapped field magnet of a nuclear magnetic resonance tool below a critical temperature.

28. The method of claim 20 wherein the parameter of interest is selected from the group consisting of (i) a horizontal of the formation, (ii) a vertical resistivity of the formation, (iii) a positions of an interface in the formation, (iv) a clay bound water of the formation, (v) bound volume irreducible, and (vi) porosity.

29. (canceled)

30. (canceled)

32. An apparatus conveyed in a borehole, the apparatus comprising:

(a) a formation evaluation sensor which makes a measurement of a property of an earth formation; and

(b) a quantum thermocooler which cools the formation evaluation sensor.