CN112127871A

CN112127871A - Downhole logging tool

Info

Publication number: CN112127871A
Application number: CN202011040649.8A
Authority: CN
Inventors: 不公告发明人
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-09-28
Filing date: 2020-09-28
Publication date: 2020-12-25

Abstract

A downhole logging tool arranged in a drill collar (2) and arranged together with the drill collar (2) in a borehole (3); the downhole logging tool comprises a cooling device capable of cooling a circuit element (11) of the logging-while-drilling tool; the downhole logging tool comprises an elongated housing (10), a seat (12) for supporting a circuit board (13) being provided in the housing (10), the circuit element being arranged on the circuit board (13), the seat (12) of the circuit board (13) being arranged in an insulation (15); the cooling device comprises a cold end (16) and a hot end (14), the cold end (16) being directly or indirectly thermally coupled to the circuit element (11); the cooling device further comprises a heat transfer device adapted to be disposed within an elongate housing (10) of the downhole logging tool, the heat transfer device maintaining the temperature of the hot end (14) at a sufficiently low temperature to enable the cooling device to operate effectively. The underground logging tool can timely and automatically cool circuit elements in high-temperature and higher-temperature strata, and protects the logging tool.

Description

Downhole logging tool

Technical Field

The present invention relates to downhole logging tools, and more particularly to downhole logging tools including cooling devices.

Background

In the process of oil and gas exploration and development, with the increase of medium-deep wells, ultra-deep wells and complex wells, the requirements on well drilling tests are higher and higher. Currently, the measurement while drilling technology is commonly adopted in the field of well drilling. The measurement while drilling technology is that a tester is installed in a drill collar, the drill collar is put into a well while drilling, in the drilling process, underground technical parameters are recorded into the tester, when a drill rod is replaced, the tester is taken out, the technical parameters stored in the tester are exported, and construction bases are provided for construction technicians. The underground temperature increases along with the increase of the well depth, and the current underground tester has no heat dissipation system because the underground temperature is too high and the power supply is insufficient, can only isolate the external heat by the heat-insulating barrel and transmit the external heat to the inside, but can not enable the heat of the original components inside to be dissipated to the environment, so that the well logging depth is greatly limited, the cost is greatly increased, and the well drilling efficiency and the cost are influenced.

Generally, there are two modes of high temperature induced circuitry failure. First, thermal stress on the circuitry reduces its useful life; second, when the temperature reaches a critical value, the circuitry fails and stops operating. Failure due to overheating not only results in increased costs for replacement of the failed circuitry, but also interrupts drilling activities, requires tripping the drill string to replace the circuitry, consumes drilling time and increases drilling costs.

Currently, there are three measures in the petroleum industry to address high temperature resistance of downhole circuits: firstly, screening out components which can be used at high temperature through high-temperature examination; secondly, customizing a high-temperature resistant component; thirdly, invest in huge expenses, independently research and develop the high temperature resistant downhole circuit. The measures are all used for solving the problem from the perspective of passive temperature resistance of the components, and the high-temperature resistance effect is limited; meanwhile, the high-temperature packaging technology of the components is still a bottleneck problem.

Accordingly, there is a need to provide an efficient, stable cooling system for downhole circuitry.

Disclosure of Invention

A downhole logging tool disposed in a drill collar, the downhole logging tool comprising a logging-while-drilling tool comprising a circuit element. The downhole logging tool comprises a cooling device capable of cooling the circuit element.

The downhole logging tool includes an elongated housing having a support disposed therein for supporting a circuit board having circuit components of a logging-while-drilling tool mounted thereon. The support comprising the circuit board is arranged in a heat insulating element comprising a heat insulator. For example, the thermal insulation may be a dewar having a vacuum chamber therein as an insulator. The insulation element comprises at least one opening and at least one fastening element which can be inserted into the at least one opening. Each fastener may contact an inner wall of the elongated housing to secure the thermal shield in the downhole logging tool. Also, each fastener may contact an end of the holder to secure the holder within the thermal shield. Multiple through holes may be provided in each fixture for routing cables and/or hydraulic lines in the downhole logging tool.

In an alternative embodiment, the insulation may comprise only one opening. Another fastener may surround the thermal shield to further secure the thermal shield in the downhole logging tool.

To transfer heat from at least some of the circuit elements and/or to maintain the temperature of at least some of the circuit elements, the downhole logging tool also includes a cooling device, such as a stirling cooler. The cooling device includes a cold end and a hot end. The cold end may be thermally coupled, directly or indirectly, to the component to be cooled.

The cold side directly contacts the circuit element. Alternatively, the cold terminals are in turn contacted by a thermal conductor to a support on which the circuit components are mounted. The thermal conductor may also be partially embedded within the fixture.

The cooling means may be arranged perpendicular to the longitudinal axis of the elongate housing. However, in order to increase the area and thus the cooling capacity of the cooling device, it may be arranged obliquely with respect to the longitudinal axis. Furthermore, the cooling device can also be partially embedded in the fastening element. To reduce heat leakage to the cold end of the cooling device and the component to be cooled, the cold end is preferably located inside the insulation. The hot end is located outside the insulation to avoid or minimize heat leakage from inside the insulation to the hot end.

The cooling device transfers heat between the cold and hot ends. Thus, the temperature of the cold side can be lower than that of the hot side, and the temperature of the two sides can be controlled to be in an optimal state by controlling the amount of power supplied to the hot side. In the event that the temperature of the wellbore formation is high, for example in a wellbore where the formation temperature is 150 degrees celsius or higher, the heat transferred by the cooling device may not be passively dissipated in the environment, and therefore the temperature of the warm end may increase over time and the efficiency of the cooling device may therefore decrease until the cooler is no longer able to transfer heat from the cold end to the warm end. In higher temperature environments, such as formation temperatures up to 200 degrees celsius, the cooling device includes a heat transfer device. The heat transfer device is adapted to be disposed within an elongated housing of a downhole logging tool. The heat transfer device may be used to maintain the temperature of the hot side at a sufficiently low temperature for the cooling device to operate effectively. The heat transfer device is capable of transferring heat from the warm end of the cooling device to the formation even when the formation is at a higher temperature than the warm end.

The heat transfer device includes a heat exchanger in contact with the hot side. The heat transfer device further comprises a heat pipe filled with a cooling fluid, active cooling of the cooling fluid being provided by a pump. That is, the pump transfers heat from the cooling fluid into the formation when energy (e.g., mechanical energy provided by an electric motor) is provided.

The pump may be based on a vapor compression cycle. As such, the pump may include a compressor and an expansion valve that are capable of varying the pressure of the cooling fluid. The hot vaporized cooling fluid (e.g., steam) entering the pump may be compressed by a compressor into a condenser. In the condenser, the cooling fluid may condense (e.g., turn into water), and heat may be dissipated into the formation. The cooling fluid may then pass through an expansion valve. During expansion, the cooling fluid is partially evaporated and cooled. A portion of the liquid cooling fluid may then exit the pump. Alternatively, the pump may comprise a stirling engine or be based on a thermodynamic cycle other than a vapour compression cycle.

The cooling fluid filling the heat pipes is used to cool the hot end of the cooling device. Thus, the hot end of the cooling device is thermally coupled to a portion of the heat pipe by a heat exchanger, and the heat exchanger includes a channel for a cooling fluid. The heat exchanger may be partially embedded within the fixture. In an alternative embodiment, the heat exchanger may be omitted and the cooling fluid filling the heat pipe may be in direct contact with the hot end of the cooling device.

In an alternative embodiment, multiple cooling means may be provided and multiple heat transfer means may be provided to enhance the cooling capabilities of the downhole logging tool.

The underground logging tool has the following beneficial effects:

the downhole logging tool includes a cooling device that transfers heat between a cold end and a hot end. Thus, the cold end can be at a lower temperature than the hot end, and the temperature at both ends can be controlled to be at an optimum state by controlling the amount of cooling.

The downhole logging tool includes insulation in which a circuit board and circuit components of the logging-while-drilling tool are disposed, delaying heating of the circuit components by the borehole formation.

The cooling means are arranged obliquely with respect to the longitudinal axis, increasing the contact area and thus the cooling capacity of the cooling means.

The cooling device includes a heat transfer device that may be used to maintain the temperature at the hot end at a sufficiently low temperature in a higher temperature environment, such as formation temperatures up to 200 degrees celsius, so that the cooling device operates efficiently. The heat transfer device is capable of transferring heat from the warm end of the cooling device to the formation even when the formation is at a higher temperature than the warm end

The cooling capacity of the downhole logging tool is further enhanced by the arrangement of the multistage cooling device and the arrangement of the multistage heat conduction device.

Drawings

FIG. 1 is a schematic representation of a tool including a downhole logging tool of the present invention;

FIG. 2 is a schematic diagram of a downhole logging tool of the present invention.

Detailed Description

In order to facilitate an understanding of the present application, the present application is described in more detail below with reference to the accompanying drawings and specific embodiments. Preferred embodiments of the present application are illustrated in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

As shown in FIG. 1, a downhole logging tool 1 is disposed in a drill collar 2 and disposed in a borehole 3 with the drill collar 2; the downhole logging tool comprises a logging-while-drilling tool comprising a circuit element. The downhole logging tool comprises a cooling device capable of cooling the circuit element.

As shown in FIG. 2, a downhole logging tool includes an elongated housing 10 disposed in a wellbore. The downhole logging tool comprises a carrier 12 for supporting a circuit board 13, the circuit board 13 having circuit elements 11 of the logging tool while drilling mounted thereon. Some of these circuit elements may benefit from being maintained at a relatively constant temperature, such as between 80 degrees celsius and 100 degrees celsius. Certain other components require cooling when their temperature reaches their nominal temperature (e.g., 150 degrees celsius).

In order to delay the heating of the circuit element 11 by the borehole formation, the carrier 12 comprising the circuit board 13 is arranged in an insulation 15, the insulation 15 comprising an insulator. For example, the thermal insulator 15 may be a dewar having a vacuum chamber therein as an insulator. The thermal insulation 15 includes at least one opening and at least one fastener 20 that can be inserted into the at least one opening. Each fastener 20 may contact an inner wall of the elongated housing 10 to secure the thermal shield 15 in the downhole logging tool. Also, each fastener 20 may contact an end of support 12 to secure support 12 within insulation 15. One or more through-holes 18 may be provided in each of the fasteners 20 for routing electrical cables and/or hydraulic lines in the downhole logging tool. In some alternative embodiments, the insulation 15 may comprise only one opening. Another fastener may surround the insulation 15 to further secure the insulation 15 in the downhole logging tool.

To transfer heat from at least some of the circuit elements 11 and/or to maintain the temperature of at least some of the circuit elements 11, the downhole logging tool further comprises a cooling device, such as a stirling cooler. The cooling device includes a cold end 16 and a hot end 14. The cold end 16 may be thermally coupled, directly or indirectly, to the component to be cooled. Cold end 16 and warm end 14 may be in contact or connected by a refrigerant connection tube 19.

Cold side 16 directly contacts circuit element 11. Alternatively, cold terminals 16 are in turn contacted by a thermal conductor to support 12 on which circuit elements 11 are mounted. The thermal conductor may also be partially embedded within the fixture 20.

As shown in fig. 1, the cooling means may be arranged perpendicular to the longitudinal axis of the elongated housing 10. However, in order to increase the area and thus the cooling capacity of the cooling device, it may be arranged obliquely with respect to the longitudinal axis. Furthermore, the cooling device may also be partially embedded in the fixing member 20. To reduce heat leakage to the cold end 16 of the cooling device and the component to be cooled, the cold end is preferably located inside the insulation 15. Hot end 14 is located outside insulation 15 to avoid or minimize heat leakage from inside insulation 15 to hot end 14.

The cooling device transfers heat between cold end 16 and hot end 14. In this way, the cold side 16 may be cooler than the hot side 14, while the temperature at both ends may be controlled at optimum by controlling the amount of power to the hot side. In situations where the temperature of the wellbore formation is not low enough, such as in a wellbore where the formation temperature is 150 degrees celsius or higher, the heat transferred by the cooling device may not be passively dissipated in the environment, and thus the temperature of hot end 14 may increase over time, and the efficiency of the cooling device may therefore decrease until the cooler is no longer able to transfer heat from cold end 16 to hot end 14. In high temperature environments, such as where the formation temperature is 150 degrees celsius or greater, the cooling device includes a heat transfer device. The heat transfer device is adapted to be disposed within an elongated housing 10 of a downhole logging tool. The heat transfer device may be used to maintain the temperature of hot end 14 at a sufficiently low temperature for the cooling device to operate effectively. The heat transfer device is capable of transferring heat from the hot end 14 of the cooling device to the formation even when the formation is at a higher temperature than the temperature of the hot end 14. For example, the formation may be at a temperature of 200 degrees celsius and the heat transfer device may be capable of maintaining the temperature of the hot end 14 of the cooling device below 150 degrees celsius.

The heat transfer device includes a heat exchanger 17, the heat exchanger 17 being in contact with the hot side 14. The heat transfer device further comprises heat pipes 22 filled with a cooling fluid, active cooling of which is provided by a pump 21. That is, the pump 21 transfers heat from the cooling fluid into the formation when energy is provided (e.g., mechanical energy provided by an electric motor).

The pump 21 may be based on a vapor compression cycle. Thus, the pump 21 may include a compressor and an expansion valve capable of varying the pressure of the cooling fluid. The hot vaporized cooling fluid (e.g., steam) entering the pump 21 may be compressed by a compressor into a condenser. In the condenser, the cooling fluid may condense (e.g., turn into water), and heat may be dissipated into the formation. The cooling fluid may then pass through an expansion valve. During expansion, the cooling fluid is partially evaporated and cooled. Part of the liquid cooling fluid may then leave the pump 21. Alternatively, the pump 21 may include a stirling engine or be based on a thermodynamic cycle other than a vapor compression cycle.

The cooling fluid filling the heat pipes is used to cool the hot end 14 of the cooling device. Thus, the hot end 14 of the cooling device is thermally coupled to a portion of the heat pipe by a heat exchanger 17, and the heat exchanger 17 comprises a channel for a cooling fluid. The heat exchanger 17 may be partially embedded within the fixture 20. In an alternative embodiment, the heat exchanger 17 may be omitted and the cooling fluid filling the heat pipes may be in direct contact with the hot end 14 of the cooling device.

In an alternative embodiment, multiple cooling means may be provided and multiple heat transfer means may be provided to enhance the cooling capabilities of the downhole logging tool. A downhole logging tool comprising a multi-stage cooling device capable of cooling a circuit element 11 of a logging-while-drilling tool; the downhole logging tool comprises an elongated housing 10, a support 12 arranged in the housing 10 for supporting a circuit board 13, the circuit components being arranged on the circuit board 13, the support 12 for the circuit board 13 being arranged in an insulating element 15, the insulating element 15 comprising a number of openings, the number of openings being the same as the number of cooling means, one fixing element 20 being inserted in each opening, each fixing element 20 contacting an inner wall of the housing 10 for fixing the insulating element 15 in the downhole logging tool; each cooling device comprises a cold side 16 and a hot side 14, said cold side 16 being thermally coupled, directly or indirectly, to said circuit element 11; each cooling device further comprises a heat transfer device adapted to be disposed within the elongate housing 10 of the downhole logging tool, the heat transfer device maintaining the temperature of the hot end 14 at a sufficiently low temperature to enable the cooling device to operate effectively.

The embodiments of the present application have been described in detail with reference to the accompanying drawings, but the present application is not limited to the described embodiments. It will be apparent to those skilled in the art that various changes, modifications, substitutions and alterations can be made herein without departing from the principles and spirit of the application, and the scope of the application is to be accorded the full scope of the claims.

Claims

1. A downhole logging tool arranged in a drill collar (2) and arranged together with the drill collar (2) in a borehole (3); the downhole logging tool comprises a cooling device capable of cooling a circuit element (11) of the logging-while-drilling tool; the method is characterized in that: the downhole logging tool comprises an elongated housing (10), a support (12) arranged in the housing (10) for supporting a circuit board (13), the circuit components being arranged on the circuit board (13), the support (12) of the circuit board (13) being arranged in an insulating element (15), the insulating element (15) comprising at least one opening and at least one fixing element (20) insertable into the at least one opening, each fixing element (20) contacting an inner wall of the housing (10) for fixing the insulating element (15) in the downhole logging tool; one or more through holes (18) are arranged on each fixing piece (20);

the thermal insulator (15) comprises an insulator which is a dewar having a vacuum chamber;

the cooling device comprises a cold end (16) and a hot end (14), the cold end (16) being directly or indirectly thermally coupled to the circuit element (11); the cold ends are preferably located inside the insulation (15); the hot end (14) is located outside the heat insulation element (15);

the cooling device further comprises a heat transfer device adapted to be disposed within an elongate housing (10) of the downhole logging tool, the heat transfer device maintaining the temperature of the hot end (14) at a sufficiently low temperature to enable the cooling device to operate effectively.

2. The downhole logging tool of claim 1 wherein: the heat transfer device is capable of maintaining the temperature of the hot end (14) of the cooling device below 150 degrees celsius at a formation temperature of 200 degrees celsius.

3. The downhole logging tool of claim 1 wherein: the heat transfer device comprises a heat exchanger (17), the heat exchanger (17) being in contact with the hot side (14).

4. A downhole logging tool according to any of claims 1-3, wherein: the heat transfer device further comprises heat pipes (22) filled with a cooling fluid, the flow of the cooling fluid being provided by a pump (21), enabling active cooling.

5. The downhole logging tool of claim 4 wherein: the heat transfer device further comprises a compressor for changing the pressure of the cooling fluid, whereby the hot vaporized cooling fluid entering the pump (21) is compressed into a condenser, where the cooling fluid condenses, thereby dissipating heat into the formation.

6. The downhole logging tool of claim 5 wherein: the heat transfer device further comprises an expansion valve through which the condensed cooling fluid is expanded, part of the cooling fluid is evaporated and cooled, and then the cooled fluid is pumped by a pump (21).

7. The downhole logging tool of claim 4 wherein: cooling fluid filling the heat pipes (22) is used for cooling the hot end (14); the hot end (14) is thermally coupled to a portion of the heat pipe (22) by a heat exchanger (17), and the heat exchanger (17) includes a channel for a cooling fluid.

8. A downhole logging tool arranged in a drill collar (2) and arranged together with the drill collar (2) in a borehole (3); the downhole logging tool comprises a multi-stage cooling device capable of cooling circuit elements (11) of the logging-while-drilling tool; the method is characterized in that: the downhole logging tool comprises an elongated housing (10), a support (12) for supporting a circuit board (13) being arranged in the housing (10), the circuit components being arranged on the circuit board (13), the support (12) of the circuit board (13) being arranged in an insulating element (15), the insulating element (15) comprising a number of openings, the number of openings being the same as the number of cooling means, one fixing element (20) being inserted in each opening, each fixing element (20) contacting an inner wall of the housing (10) for fixing the insulating element (15) in the downhole logging tool;

each cooling device comprising a cold end (16) and a hot end (14), the cold end (16) being directly or indirectly thermally coupled to the circuit element (11);

each cooling device further comprises a heat transfer device adapted to be disposed within the elongate housing 10 of the downhole logging tool, the heat transfer device maintaining the temperature of the hot end (14) at a sufficiently low temperature to enable the cooling device to operate effectively.

9. The downhole logging tool of claim 8 wherein: the heat transfer device is capable of maintaining the temperature of the hot end (14) of the cooling device below 150 degrees celsius at a formation temperature of 200 degrees celsius.

10. The downhole logging tool of claim 8 wherein: the cold end (16) and the hot end (14) are connected through a refrigeration connecting pipe (19).