US20180347336A1

US20180347336A1 - System for improving the usage of a thermoelectric cooler in a downhole tool

Info

Publication number: US20180347336A1
Application number: US15/612,202
Authority: US
Inventors: Daniel Philip Kusmer; Nicolas Alejandro Wolk
Original assignee: Vierko Enterprises LLC
Current assignee: Vierko Enterprises LLC
Priority date: 2017-06-02
Filing date: 2017-06-02
Publication date: 2018-12-06
Also published as: CA3006217A1; EP3409884A1

Abstract

A downhole tool comprises a chassis for supporting printed circuit boards having electrical components mounted thereon. The downhole tool comprises at least one thermoelectric cooler, such as a Peltier cooler, for cooling particular electrical components. The downhole tool also comprises a heat pump that may be used for maintaining the temperature of the hot side of the thermoelectric cooler to a sufficiently low temperature so that the thermoelectric cooler works efficiently. The heat pump may further be used for providing additional cooling in the downhole tool.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

None

BACKGROUND

This disclosure relates generally to methods and apparatus for actively cooling downhole electronics or other components contained within a downhole tool. More particularly, this disclosure relates to systems for improving the usage of a thermoelectric cooler in a downhole tool. For example, this disclosure relates to systems for improving the usage of a Peltier cooler in a logging tool used for oil and gas exploration or production.
Peltier coolers are active heat pumps which transfer heat between a cool side and a hot side upon supply and consumption of electric energy. Peltier coolers have a cooling power per unit of surface area that is usually smaller than other heat pumps. The temperature differential between the hot side and the cool side at which Peltier coolers operate efficiently is limited, typically to approximately 70 degrees C. The cool side and the hot side of Peltier coolers are normally located adjacent to each other, which limits the distance over which Peltier coolers can transfer heat.
Nevertheless, Peltier coolers can be advantageous for use in a downhole tool because these coolers do not have moving parts or a circulating fluid. For example, Peltier coolers may be used for providing local thermal regulation of relatively small downhole tool components that need to be maintained within a specific temperature range to operate properly.
When the temperature differential between the wellbore and the downhole tool component to be cooled is large, Peltier coolers may become unsuitable because of their inefficiency. For example, Peltier coolers may not be usable to transfer heat from a downhole tool component that is at a temperature of 80 degrees C. to a wellbore environment that is at a temperature of 150 degrees C. or above.
When Peltier coolers are used for transferring heat from the inside of a Dewar flask to the outside of the Dewar flask, the position of the Peltier cooler is typically constrained to the space leading to the opening of the Dewar flask. This constrained location of the Peltier cooler may make the cooling of components located deep inside the flask problematic. This constrained location of the Peltier cooler also imposes limits on the area of the cooler and, in turn, on its cooling power. For example, in a downhole tool, Peltier coolers may typically have an area that limits their cooling power to approximately 15 Watts. Thus, Peltier coolers may not be usable to cool a plurality of components located along a Dewar flask.
Accordingly, there is a continuing need in the art for methods and apparatus for improving the usage of thermoelectric coolers, such as Peltier coolers, in a downhole tool.

BRIEF SUMMARY OF THE DISCLOSURE

The disclosure describes an apparatus for use in a downhole tool that comprises at least one thermoelectric cooler. The thermoelectric cooler may be adapted for thermal coupling to a component mounted on a chassis of the downhole tool. The apparatus further comprises a heat pump adapted for disposal into an elongated pressure housing of the downhole tool. The heat pump includes a conduit that is filled with a cooling fluid. The heat pump may include a compressor or a loudspeaker capable of varying a cooling fluid pressure. In some embodiments, the heat pump includes a compressor and an expansion valve. The thermoelectric cooler includes a cold side and a hot side. The hot side of the thermoelectric cooler is thermally coupled to a portion of the conduit.
The apparatus may further comprise one or more thermally insulating housings. Each thermally insulating housing includes at least one opening. A thermally insulating housing may include one or more compartments. The apparatus may further comprise at least one thermally insulating support. The thermally insulating support may be inserted into the opening of the thermally insulating housing. The thermoelectric cooler may be partially embedded within the thermally insulating support. The cold side of the thermoelectric cooler may be located inside the thermally insulating housing.
The apparatus may further comprise a heat exchanger. The heat exchanger contacts the hot side of the thermoelectric cooler. The heat exchanger includes a passageway for the cooling fluid. The apparatus may further comprise a thermal conductor. The thermal conductor contacts the cold side of the thermoelectric cooler. The heat exchanger and/or the thermal conductor may be partially embedded within a thermally insulating support.
In some embodiments, the apparatus comprises at least first and second thermoelectric coolers. The hot side of the first thermoelectric cooler may be thermally coupled to a first portion of the conduit. The hot side of the second thermoelectric cooler may be thermally coupled to a second portion of the conduit. Either or both of the first and second thermoelectric coolers may be partially embedded within a thermally insulating support that may be inserted into an opening of a thermally insulating housing. The cold side of either or both of the first and second thermoelectric coolers may be located inside the same compartment of one thermally insulating housing, inside different compartments of one thermally insulating housing, or inside different thermally insulating housings.
In some embodiments, the conduit may comprise first and second portions. The hot side of the thermoelectric cooler may be thermally coupled to the first portion of the conduit. The cold side of the thermoelectric cooler may be located inside one compartment of one thermally insulating housing. The second portion may be located inside another compartment of the thermally insulating housing or inside another thermally insulating housing.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more detailed description of the embodiments of the disclosure, reference will now be made to the accompanying drawings, wherein:

FIG. 1 is a sectional view of a downhole tool including a thermoelectric cooler and a heat pump for improving the usage of the thermoelectric cooler, the heat pump involving a Vapor Compression Cycle;

FIG. 2 is a sectional view of a downhole tool including two thermoelectric coolers and a heat pump for improving the usage of the two thermoelectric coolers;

FIG. 2A is a sectional view of another downhole tool including two thermoelectric coolers and a heat pump, wherein the two thermoelectric coolers are located inside different compartments of one thermally insulating housing, or inside different thermally insulating housings;

FIG. 3 is a sectional view of a downhole tool including a thermoelectric cooler and a heat pump for improving the usage of the thermoelectric cooler and for providing additional cooling in the downhole tool; and

FIG. 4 is a sectional view of a downhole tool including a thermoelectric cooler and a heat pump for improving the usage of the thermoelectric cooler, the heat pump involving an alternative to involving a Vapor Compression Cycle.

DETAILED DESCRIPTION

It is to be understood that the following disclosure describes several exemplary embodiments for implementing different features, structures, or functions of the invention. Exemplary embodiments of elements, arrangements, and configurations are described below to simplify the disclosure; however, these exemplary embodiments are provided merely as examples and are not intended to limit the scope of the invention. Additionally, the disclosure may repeat reference numerals and/or letters in the various exemplary embodiments and across the Figures provided herein. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various exemplary embodiments and/or configurations discussed in the various Figures. Finally, the exemplary embodiments presented below may be combined in any combination of ways, i.e., any element from one exemplary embodiment may be used in any other exemplary embodiment, without departing from the scope of the disclosure.
All numerical values in this disclosure may be approximate values unless otherwise specifically stated. Accordingly, various embodiments of the disclosure may deviate from the numbers, values, and ranges disclosed herein without departing from the intended scope. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed interposing the first and second features, such that the first and second features may not be in direct contact.
Certain terms are used throughout the following description and claims to refer to particular elements. As one skilled in the art will appreciate, various entities may refer to the same element by different names, and as such, the naming convention for the elements described herein is not intended to limit the scope of the invention, unless otherwise specifically defined herein. Further, the naming convention used herein is not intended to distinguish between elements that differ in name but not function.
Referring initially to FIG. 1, a downhole tool, such as a logging tool used in oil and gas exploration or production, is illustrated in accordance with some embodiments. The downhole tool comprises an elongated pressure housing 10 that is conveyed in a wellbore drilled into the earth.
The downhole tool comprises a chassis 34 for supporting printed circuit boards 36 having electrical components 38 mounted thereon. Some of these components, such as a high precision clock, a gyroscope, or a particle detector, may benefit from being maintained at a relatively constant temperature, for example, between 80 degrees C. and 100 degrees C. Other components, such as certain electronics circuits, may only need to be cooled when their temperature reaches their rating temperature, for example, 150 degrees C.
In some cases, the wellbore environment in some locations along the wellbore may exceed 80 degrees C., and even 150 degrees C. For delaying the heating of the electrical components 38 by the wellbore environment, the chassis 34, including the printed circuit boards 36 and the electrical components 38, may be disposed within a thermally insulating housing 26. The thermally insulating housing 26 comprises a thermal insulator 28. For example, the thermally insulating housing 26 may be a Dewar flask having a vacuum chamber therein as an insulator. The thermally insulating housing 26 includes at least one opening and at least one thermally insulating support 30 that may be inserted into the at least one opening. Each thermally insulating support 30 may contact the inner wall of the elongated pressure housing 10 for securing the thermally insulating housing 26 in the downhole tool. Also, each thermally insulating support 30 may contact an end of the chassis 34 for securing the chassis 34 within the thermally insulating housing 26. A plurality of feed-thru passages 32 may be provided across each thermally insulating support 30 for running electrical wires, and/or hydraulic lines in the downhole tool. In some alternative embodiments, the thermally insulating housing 26 may include only one opening. Another thermally insulating support may surround the thermally insulating housing 26 for further securing the thermally insulating housing 26 in the downhole tool.
For transferring heat from at least some of the electrical components 38 and/or for maintaining the temperature of at least some of the electrical components 38, the downhole tool further comprises a thermoelectric cooler 12, such as a Peltier cooler. Examples of electrical components 38 that may benefit from temperature regulation with the thermoelectric cooler 12 include, but are not restricted to, high precision clocks, gyroscopes, or particle detectors.
The thermoelectric cooler 12 includes a cold side 16 and a hot side 14. The cold side 16 may be directly or indirectly thermally coupled to the component to be cooled. For example, a thermal conductor 42 may contact the cold side 16 of the thermoelectric cooler 12. The thermal conductor 42 may, in turn, contact the chassis 34 on which the electrical components 38 are mounted. Alternatively, the thermal conductor 42 may directly contact the electrical components 38, or may even by omitted by having the cold side 16 contacting the electrical components 38. In various embodiments, the thermal conductor 42 may include a heat pipe, or a material having a large thermal conductivity, such as aluminum. The thermal conductor 42 may be partially embedded within the thermally insulating support 30.
As shown, the thermoelectric cooler 12 may be disposed perpendicularly to the longitudinal axis of the elongated pressure housing 10. However, for increasing the area and thus the cooling power of the thermoelectric cooler 12, it can alternatively be disposed tilted relative to the longitudinal axis of the elongated pressure housing 10. Further, the thermoelectric cooler 12 may be partially embedded within the thermally insulating support 30. For reducing the leakage of heat toward the cold side 16 of the thermoelectric cooler 12 and the component to be cooled, the cold side 16 may preferably be located inside the thermally insulating housing 26. The hot side 14 may be located outside the thermally insulating housing 26 to avoid or minimize leakage of heat from the hot side 14 inside the thermally insulating housing 26.
The thermoelectric cooler 12 transfers heat between the cold side 16 and the hot side 14. As such, the temperature of the cold side 16 may be lower than the temperature of the hot side 14 by an amount controllable by the electric power supplied to the thermoelectric cooler 12. However, that amount may be limited to approximately 70 degrees C. For example, the temperature of the cold side 16 may be in the range between 80 degrees C. and 100 degrees C. The temperature of the hot side 14 may thus be limited to a maximum temperature of 150 degrees C. In cases where the wellbore environment is at a temperature sufficiently below (e.g., 20 degrees C. below) the temperature of the hot side 14, the heat transferred by the thermoelectric cooler 12 may passively dissipate from the hot side 14 into the wellbore environment.
In cases where the temperature of the wellbore environment is not sufficiently low, for example in wellbores that have an environment at a temperature of 150 degrees C. or above, the heat transferred by the thermoelectric cooler 12 may not passively dissipate in the environment, the temperature of the hot side 14 may thus increase over time, and the efficiency of the thermoelectric cooler 12 may consequently decrease until the cooler is no longer capable of transferring heat from the cold side 16 to the hot side 14. For evacuating the heat transferred by the thermoelectric cooler 12 even in such hot environments, the downhole tool comprises a heat pump 18. The heat pump 18 is adapted for being disposed within the elongated pressure housing 10 of the downhole tool. The heat pump 18 may be used for maintaining the temperature of the hot side 14 to a sufficiently low temperature so that the thermoelectric cooler 12 works efficiently. The heat pump 18 actively transfers heat from the hot side 14 of the thermoelectric cooler 12 to the wellbore environment, even when the wellbore environment is at a temperature higher than the temperature of the hot side 14. For example, the wellbore environment may be at a temperature of 200 degrees C., and the heat pump 18 may be capable of maintaining the temperature of the hot side 14 of the thermoelectric cooler 12 below 150 degrees C.
The heat pump 18 includes a conduit that is filled with a cooling fluid. The heat pump 18 provides active cooling of the cooling fluid. That is, upon supply of energy (e.g., mechanical energy provided by a motor), the heat pump 18 transfers heat from the cooling fluid into the wellbore environment.
Preferably, the heat pump 18 may be based on a Vapor Compression Cycle. As such, the heat pump 18 may include a compressor 22 and an expansion valve 20, capable of varying a cooling fluid pressure. Hot vaporized cooling fluid (e.g., steam) entering the heat pump 18 may be compressed by the compressor 22 into a condenser (not shown). In the condenser, the cooling fluid may condense (e.g., into water) and heat may dissipate into the wellbore environment. The cooling fluid may then pass through the expansion valve 20. During expansion, the cooling fluid partially vaporizes and cools. Cold, partially liquid cooling fluid may then leave the heat pump 18. Alternatively, the heat pump 18 may comprise a Stirling engine or be based on thermodynamic cycles other than the Vapor Compression Cycle.
The cooling fluid filling the conduit is used for cooling the hot side 14 of the thermoelectric cooler 12. Accordingly, the hot side 14 of the thermoelectric cooler 12 is thermally coupled to a portion 24 of the conduit. For example, the downhole tool may further comprise a heat exchanger 40. The heat exchanger 40 contacts the hot side 14 of the thermoelectric cooler 12 and the heat exchanger 40 includes a passageway for the cooling fluid. The heat exchanger 40 may be partially embedded within the thermally insulating support 30. In some embodiments, the heat exchanger 40 may include a heat pipe. In alternative embodiments, the heat exchanger 40 may be omitted and the cooling fluid filling the conduit may be directly in contact with the hot side 14 of the thermoelectric cooler 12.
Using a combination of a thermoelectric cooler with a heat pump based on a Vapor Compression Cycle or another thermodynamic cycle may be advantageous over cascading several thermoelectric coolers. For example, cascading several thermoelectric coolers to maintain a large temperature difference between a downhole component and the wellbore environment typically leads to a lower efficiency than the combination of a single thermoelectric cooler with a heat pump. Further, using a combination of a thermoelectric cooler with a heat pump based on a Vapor Compression Cycle may be advantageous over using only a heat pump. Indeed, the cooling fluid selected for use in the Vapor Compression Cycle may be efficient to only cool a downhole component over a certain temperature range that depends on the phase transition temperature(s) of the cooling fluid. Combining a thermoelectric cooler with the heat pump may increase the temperature range at which a downhole component may be cooled with a particular cooling fluid.
Turning to FIG. 2, another downhole tool is illustrated in accordance with some embodiments in which the downhole tool may comprise at least a first thermoelectric cooler 12 a and a second thermoelectric cooler 12 b. In some embodiments, the configuration of FIG. 2 may be used when a plurality of components located along the downhole tool (e.g., along a thermally insulating housing 26) are to be cooled. Preferably, the configuration of FIG. 2 may be used when the downhole components cooled by the first thermoelectric cooler 12 a are maintained at a temperature equal or sufficiently close to the temperature at which the downhole components cooled by the second thermoelectric cooler 12 b are maintained. The configuration of FIG. 2 may also provide an increased combined area of the first thermoelectric cooler 12 a and the second thermoelectric cooler 12 b, and thus an increased cooling power, while avoiding or minimizing leakage of heat from the hot sides of the first thermoelectric cooler 12 a and the second thermoelectric cooler 12 b inside a thermally insulating housing 26.
The hot side 14 a of the first thermoelectric cooler 12 a may be thermally coupled to a first portion 24 a of the conduit. The hot side 14 b of the second thermoelectric cooler 12 b may be thermally coupled to a second portion 24 b of the conduit. In some embodiments, the first portion 24 a and the second portion 24 b of the conduit may be assembled in series. Accordingly, cooling fluid leaving the heat pump 18 may first circulate through the first portion 24 a, then circulate through the second portion 24 b before entering the heat pump 18. In other embodiments, the first portion 24 a and the second portion 24 b of the conduit may be assembled in parallel. Accordingly, the flow of cooling fluid leaving the heat pump 18 may be split into a first stream of cooling fluid that circulates through the first portion 24 a, and a second stream of cooling fluid that circulates through the second portion 24 b. The first and second streams may then rejoin and enter the heat pump 18.
When the first portion 24 a and the second portion 24 b of the conduit are assembled in series as explained hereinabove, the cooling of the hot side 14 a of the first thermoelectric cooler 12 a may be more efficient than the cooling of the hot side 14 b of the second thermoelectric cooler 12 b because the cooling fluid may have vaporized and/or heated at the hot side 14 a before reaching the hot side 14 b. Accordingly, the second thermoelectric cooler 12 b may be used for cooling components that produce more heat than the components cooled by the first thermoelectric cooler 12 a.
Either or both of the first thermoelectric cooler 12 a and second thermoelectric cooler 12 b may be partially embedded within a thermally insulating support 30 that may be inserted into opposite openings of a thermally insulating housing 26. The cold side 16 a or 16 b of either or both of the thermoelectric coolers may be located inside the thermally insulating housing 26.
Turning to FIG. 2A, another downhole tool is illustrated in accordance with some embodiments in which the thermally insulating housing 26 may include a first compartment 101 and a second compartment 102. In contrast with the configuration shown in FIG. 2, the configuration of FIG. 2A may preferably be used when the downhole components cooled by the first thermoelectric cooler 12 a are maintained at a temperature different from the temperature at which the downhole components cooled by the second thermoelectric cooler 12 b are maintained. In this example, the first compartment 101 and the second compartment 102 may each include only one opening. One thermally insulating support 30, provided with one or more feed-thru passages 32, may be inserted into each of the openings. The cold side 16 a of the thermoelectric cooler 12 a may be located inside the first compartment 101. The cold side 16 b of the thermoelectric cooler 12 b may be located inside the second compartment 102. In alternative embodiments, a downhole tool may comprise more than one thermally insulating housing 26, in a way similar to the downhole tool illustrated in FIG. 2A.
Turning to FIG. 3, another downhole tool is illustrated in accordance with some embodiments in which the downhole tool may comprise a conduit having a first portion 24 a and a second portion 24 b. The hot side 14 of the thermoelectric cooler 12 may be thermally coupled to the first portion 24 a of the conduit. The second portion 24 b may be located inside the thermally insulating housing 26. The second portion 24 b may be used for providing additional cooling to electrical components 38 that are too far from the cold side 16 of the thermoelectric cooler 12 to be sufficiently cooled by the thermoelectric cooler 12. For example, the thermoelectric cooler 12 may be used for maintaining a particular downhole tool components, such as a high precision clock, a gyroscope, or a particle detector, at a relatively constant temperature, for example, between 80 degrees C. and 100 degrees C. The second portion 24 b of the conduit may be used for cooling other components, such as certain electronics circuits, only such that their temperature does not exceed their rating temperature, for example, 150 degrees C. Again, because of the difference of temperatures at which the downhole components are maintained, the cold side 16 of the thermoelectric cooler 12 may preferably be located inside one compartment (i.e., the compartment 101) of one thermally insulating housing. The second portion 24 b may preferably be located inside another compartment (i.e., the compartment 102) of the thermally insulating housing 26 or inside another thermally insulating housing.
The first portion 24 a and the second portion 24 b of the conduit may be assembled in series or in parallel, as explained hereinabove with respect to FIG. 2. When the first portion 24 a and the second portion 24 b are assembled in series, consideration may be given to whether the cooling fluid circulates first through the first portion 24 a or the second portion 24 b. Having the cooling fluid circulate first through the first portion 24 a may further reduce the temperature of the hot side 14 of the thermoelectric cooler 12, and thus, may improve the efficiency of the thermoelectric cooler 12. Having the cooling fluid circulate first through the second portion 24 b may reduce the amount of heat leaked from the cooling fluid inside the thermally insulating housing 26.
Turning to FIG. 4, another downhole tool is illustrated in accordance with some embodiments in which the heat pump 18 comprises a thermoacoustic heat pump, a Stirling and/or a Brayton cycle heat pump, or a thermomagnetic heat pump.
In some embodiments, a thermoacoustic heat pump 18 is configured to generate waves into a cooling fluid. Upon propagation through a thermal stack, the waves attenuate, and heat is transferred from one end of the thermal stack to the other end of the thermal stack. The heat pump 18 comprises a loudspeaker 44 capable of varying (or cycling) the cooling fluid pressure. For example the loudspeaker 44 may include piezo-electric material. The hot side 14 of the thermoelectric cooler 12 is thermally coupled to the portion 24 of the conduit. For example, the downhole tool may further comprise a heat exchanger 40. The heat exchanger 40 contacts the hot side 14 of the thermoelectric cooler 12 and includes a porous passageway for the cooling fluid. The heat exchanger 40 is further thermally coupled to the thermal stack (not shown) extending in the conduit from the heat exchanger 40 toward another heat exchanger (not shown) thermally coupled to the wellbore.
In some other embodiments, a Stirling and/or a Brayton cycle heat pump 18 is configured to pump a compressible fluid back and forth between two chambers and compress or decompress the compressible fluid. Heat is dissipated from the compressed fluid into a heat exchanger (not shown) thermally coupled to the wellbore, and heat is absorbed by the decompressed fluid from the heat exchanger 40.
In yet other embodiments, a thermomagnetic heat pump 18 is configured to circulate a conductive fluid back and forth between the heat exchanger 40 and the heat exchanger thermally coupled to the wellbore, across at least one chamber containing a ferromagnetic material in a variable magnetic field. The ferromagnetic material is cooled by removing the magnetic field. Some of the heat of the conductive fluid is absorbed by the ferromagnetic material as the conductive fluid flows in the direction toward the heat exchanger 40 across the chamber containing the ferromagnetic material, thus cooling the conductive fluid. The cold conductive fluid is used to absorb heat from the heat exchanger 40 and from the thermoelectric cooler 12. Then, the ferromagnetic material is further heated by re-applying the magnetic field. Some of the heat generated in the ferromagnetic material is transferred from the ferromagnetic material into the conductive fluid as the conductive fluid flows backward across the chamber containing the ferromagnetic material in the direction toward the heat exchanger thermally coupled to the wellbore. The heat of the conductive fluid is then dissipated into the wellbore environment at the heat exchanger thermally coupled to the wellbore.
While the disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and description. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the claims to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the claims.

Claims

1. An apparatus for use in a downhole tool, comprising:

a first thermoelectric cooler including a cold side and a hot side; and

a heat pump including a conduit filled with a cooling fluid,

wherein the heat pump is adapted for disposal within an elongated pressure housing of the downhole tool, and

wherein the hot side of the first thermoelectric cooler is thermally coupled to a first portion of the conduit.

2. The apparatus of claim 1, further comprising:

a second thermoelectric cooler including a cold side and a hot side,

wherein the hot side of the second thermoelectric cooler is thermally coupled to a second portion of the conduit.

3. The apparatus of claim 1, wherein the heat pump includes a compressor and an expansion valve.

4. The apparatus of claim 1, wherein the heat pump includes a compressor or a loudspeaker capable of varying a cooling fluid pressure.

5. The apparatus of claim 4, further comprising:

a thermally insulating housing including an opening,

wherein the cold side of the first thermoelectric cooler is located inside the thermally insulating housing.

6. The apparatus of claim 4, further comprising:

a thermally insulating housing including an opening; and

a thermally insulating support,

wherein the thermally insulating support is inserted into the opening of the thermally insulating housing, and

wherein the first thermoelectric cooler is partially embedded within the thermally insulating support.

7. The apparatus of claim 1, further comprising:

a thermally insulating housing including an opening;

8. The apparatus of claim 7, further comprising:

a second thermoelectric cooler including a cold side and a hot side,

wherein the cold side of the second thermoelectric cooler is located inside the thermally insulating housing, and

9. The apparatus of claim 8, wherein the thermally insulating housing includes a first compartment and a second compartment, wherein the cold side of the first thermoelectric cooler is located inside the first compartment, and wherein the cold side of the second thermoelectric cooler is located inside the second compartment.

10. The apparatus of claim 7, further comprising:

a second thermoelectric cooler including a cold side and a hot side; and

a second thermally insulating housing,

wherein the cold side of the second thermoelectric cooler is located inside the second thermally insulating housing, and

11. The apparatus of claim 7, further comprising:

a heat exchanger including a passageway for the cooling fluid;

a thermal conductor; and

a thermally insulating support,

wherein the heat exchanger contacts the hot side of the first thermoelectric cooler,

wherein the thermal conductor contacts the cold side of the first thermoelectric cooler, and

wherein the heat exchanger and the thermal conductor are partially embedded within the thermally insulating support.

12. The apparatus of claim 11, wherein the thermally insulating support is inserted into the opening of the thermally insulating housing.

13. The apparatus of claim 1, further comprising:

a thermally insulating housing including an opening; and

a thermally insulating support,

14. The apparatus of claim 13, further comprising:

a second thermoelectric cooler including a cold side and a hot side,

15. The apparatus of claim 13, further comprising:

a second thermoelectric cooler including a cold side and a hot side; and

a second thermally insulating housing,

16. The apparatus of claim 13, wherein the conduit further comprises a second portion located inside the thermally insulating housing.

17. The apparatus of claim 16, wherein the thermally insulating housing includes a first compartment and a second compartment, wherein the cold side of the first thermoelectric cooler is located inside the first compartment, and wherein the second portion is located inside the second compartment.

18. The apparatus of claim 13, further comprising:

a second thermally insulating housing,

wherein the conduit further comprises a second portion located inside the second thermally insulating housing.

19. The apparatus of claim 13, wherein the cold side of the first thermoelectric cooler is located inside the thermally insulating housing.

20. The apparatus of claim 13, further comprising:

a heat exchanger including a passageway for the cooling fluid; and

a thermal conductor,

21. The apparatus of claim 1, wherein the first thermoelectric cooler is adapted for thermal coupling to a component mounted on a chassis of the downhole tool.

22. The apparatus of claim 16, wherein the first portion and the second portion of the conduit are assembled in series such that the cooling fluid leaving the heat pump circulates through the first portion and then through the second portion before reentering the heat pump.

23. The apparatus of claim 1, wherein the first thermoelectric cooler is disposed tilted relative to a longitudinal axis of the elongated pressure housing.