A geothermal well temperature measuring sub

Abstract

The application provides a geothermal well temperature measuring short section, a heat insulation bushing of the temperature measuring short section is internally embedded with an electrically conductive ring and a temperature measuring bus, the electrically conductive ring is connected with the temperature measuring bus, and the temperature measuring bus is connected with a temperature measuring module; an outer temperature sensor is installed on the outer side of the temperature measuring short section, an inner temperature sensor is installed on the inner side, a temperature measuring module is installed in a temperature measuring cavity, and the inner and outer temperature sensors are connected with the temperature measuring module through wires; the temperature measuring module can simultaneously process the inner and outer side temperature data measured by the inner and outer temperature sensors into digital signals with address codes, and transmit the digital signals to a ground special processor through the temperature measuring bus, so that the inner and outer side temperatures of the temperature measuring short section are simultaneously measured; the temperature measuring cavity is filled with temperature measuring cavity heat insulation materials, heat transfer between the inner and outer sides of the temperature measuring short section is interrupted, the heat insulation and heat preservation effect of the temperature measuring short section is greatly improved, and the inner and outer side temperature measurement results are more accurate; and the structural design is suitable for full size type design of the temperature measuring short section.

Description

Technical Field

[0001] This invention relates to the field of geothermal energy development logging technology, specifically to a geothermal well temperature measurement sub. Background Technology

[0002] Geothermal energy is a clean and renewable energy source. Currently, the technology of forming a closed-loop heat exchange in the well by installing buried pipe heat exchangers has overcome the problems of limited land area for shallow geothermal energy and difficulties in water intake and reinjection for deep hydrothermal energy, and has become a new mainstream technology for the development of medium and deep geothermal energy.

[0003] Medium-deep geothermal technology primarily involves heat transfer through contact between an external heat exchanger and the surrounding soil and rock mass, with an internal insulated pipe for hot fluid output. Energy transfer occurs through the heat exchange station, forming a cycle. This complex, unsteady-state heat transfer process occurs between the fluid within the heat exchanger, the pipe wall, and the surrounding soil and rock. The heat transfer characteristics are significantly influenced by the thermophysical parameters of the soil and rock mass and the geothermal field. Geothermal field characteristics include the initial geothermal field, the dynamic temperature changes of the surrounding soil and rock mass during heat exchange, and the temperature field recovery after heat exchange ceases. Monitoring the geothermal field of medium-deep geothermal wells mainly involves long-term dynamic temperature measurement using temperature sensors installed on the inner and outer pipe walls of the buried pipe heat exchanger within the well. Conventional temperature sensors include thermocouple sensors, thermistor sensors, resistance temperature sensors (RTDs), analog temperature sensors, digital temperature sensors, and distributed fiber optic sensors. Due to accuracy and technical limitations, distributed fiber optic sensors and digital temperature sensors are more commonly used in medium-deep geothermal wells, with digital temperature sensors offering higher measurement accuracy. Currently, temperature measurement technology for medium-deep geothermal wells deeper than 2000m is still immature, with numerous failure cases. This is mainly due to the complex process of installing the temperature measurement system downhole. During the lowering of the temperature measurement cable, which is externally mounted on the pipe wall, collisions and friction with the surrounding rock mass and annular sidewalls, as well as uneven stress during connection with the downhole pipeline, easily cause damage to the cable, leading to installation failure of the geothermal field monitoring system and the inability to complete geothermal temperature monitoring. Furthermore, the temperature sensors or optical fibers need to be placed in a closed underground heat transfer medium for extended periods, requiring extremely high levels of resistance to high temperatures, high pressures, corrosion, oxidation, hydrogen loss, magnetic field interference, radiation, insulation, and sealing.

[0004] To address the aforementioned issues, a geothermal well temperature measurement sub is invented. By designing and installing internal and external temperature sensors on the sub, the temperature of the inner and outer pipes of the buried pipe heat exchanger can be measured. The sensors are in close contact with the temperature measurement point, and the temperature sensor wires and information transmission bus are also buried inside the sub and protected by the external air duct of the sub, eliminating the possibility of damage to the temperature measurement cables during the lowering and installation process. Furthermore, the sub forms an integral structure with the heat exchanger, and the sub also has good thermal insulation performance, making the temperature measurement less affected by the underground environment and resulting in higher measurement accuracy. Summary of the Invention

[0005] The purpose of this invention is to provide a geothermal well temperature measurement short section for extracting medium-deep geothermal energy using a single-well heat exchange method. It features reliable transmission of measured temperature data, simultaneous measurement of the temperature on both the inner and outer sides of the temperature measurement short section, flexible arrangement of measurement points, strong temperature resistance, high pipe strength, low apparent thermal conductivity, and long service life. It can also be used in other methods of extracting medium-deep geothermal energy.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A geothermal well temperature sensing section is connected to a cable-type composite insulated pipe string. The temperature sensing section comprises: A-end connector female thread 1, A-end connector 2, A-end heat insulation bushing inner surface 3, A-end heat insulation bushing 4, core tube A-end inner surface 5, core tube 6, A-end connector temperature sensing cavity outer tube weld 7, temperature sensing cavity outer tube 8, A-end connector core tube weld 9, temperature sensing cavity insulation material 10, B-end connector core tube weld 11, B-end connector temperature sensing cavity outer tube weld 12, B-end connector 13, B-end heat insulation bushing 14, B-end connector male thread 15, B-end heat insulation bushing outer surface 16, core tube B-end outer surface 17, high-temperature resistant sealing ring 18, core tube B-end sealing groove 19, B-end No. 1 conductive ring 20, B-end No. 2 conductive ring 21, B-end connector main bus through hole 22, No. 1 bus 23, No. 2 bus 24. The components include: A-end connector bus wire hole 25, bus 3 26, bus 4 27, A-end conductive ring 1 28, A-end conductive ring 2 29, temperature measuring chamber stepped hole 30, stepped surface inner ring sealing groove 31, cover plate fastening threaded hole 32, stepped surface outer ring sealing groove 33, temperature measuring chamber stepped surface 34, temperature measuring chamber cover plate 35, external temperature sensor mounting hole 36, external temperature sensor 37, module set threaded hole 38, cover plate fastening bolt 39, cover plate fastening stepped hole 40, A-end connector internal temperature wire hole 41, internal temperature sensor mounting hole 42, internal temperature sensor 43, internal temperature wire 1 44, internal temperature wire 2 45, temperature measuring module set screw 46, temperature measuring module 47, external temperature wire 1 48, external temperature wire 2 49, temperature measuring module fixing hole 50, outer ring sealing ring 51, and inner ring sealing ring 52.

[0008] The aforementioned temperature measuring section consists of an A-end connector, an outer tube for the temperature measuring chamber, a B-end connector, and a core tube, forming a sealed temperature measuring chamber segment.

[0009] The temperature measuring chamber of the aforementioned temperature measuring section is designed with a temperature measuring chamber cover plate on the outer tube. A temperature measuring module is installed on the inner surface of the cover plate, and an external temperature sensor is installed on the outer surface. The external temperature sensor and the temperature measuring module are connected by wires.

[0010] An internal temperature sensor is installed on the core tube of the temperature measuring cavity section of the aforementioned temperature measuring section. An internal temperature measuring hole is designed on the A-end connector. The internal temperature sensor and the temperature measuring module are connected by a wire.

[0011] The temperature measuring chamber of the aforementioned temperature measuring section is equipped with a temperature measuring bus, which is connected to the temperature measuring module. The cavity is filled with heat insulation material, which blocks the heat transfer between the inside and outside of the temperature measuring section.

[0012] The aforementioned temperature measuring section has a temperature measuring bus and a conductive ring embedded in the thermal insulation bushing at end A, with the conductive ring connected to the temperature measuring bus respectively.

[0013] The temperature measuring bus and conductive ring are embedded in the heat insulation bushing at end B of the aforementioned temperature measuring section, and the conductive ring is connected to the temperature measuring bus respectively.

[0014] The A-end connector of the aforementioned temperature measuring section has a wire hole. The temperature measuring bus embedded in the heat insulation bushing of the A-end passes through the wire hole, which is filled with high-temperature resistant insulating sealant.

[0015] The B-end connector of the aforementioned temperature measuring section is machined with a wire hole. The temperature measuring bus embedded in the heat insulation bushing of the B-end passes through the wire hole, which is filled with high-temperature resistant insulating sealant.

[0016] The core tube of the aforementioned temperature measuring section passes through the inner through hole of the A-end connector and is welded together. The heat insulation bushing of the A-end is wrapped and fixed to the outer surface of the core tube.

[0017] The core tube of the aforementioned temperature measuring section passes through the inner through hole of the B-end connector and is welded together. The heat insulation bushing at the B-end is fixed to the outer surface of the core tube.

[0018] The outer tube of the temperature measuring chamber of the aforementioned temperature measuring section is formed by welding two semi-joint tubes together, and then welding them together with the A end face connector and the B end connector respectively.

[0019] As a preferred option, the connectors and core tubes at both ends A and B of the temperature measuring section are made of materials and steel grades that meet API standards.

[0020] As a preferred option, the thermal insulation bushings at both ends A and B of the temperature measuring section are made of alicyclic epoxy fiberglass or polyimide fiberglass, which are fiberglass materials with a long-term temperature resistance greater than 150℃.

[0021] Preferably, the temperature measuring cavity of the temperature measuring section is made of heat-insulating materials such as nano-aerogel or ceramic fiber.

[0022] Preferably, the threads of the A and B ends of the temperature measuring section can be threadedly fastened to a cable-type composite insulation pipe with a matching size structure.

[0023] Preferably, the thermal insulation bushings and core tubes at ends A and B of the temperature measuring section can be plugged into a cable-type composite insulation pipe with matching dimensions.

[0024] As a preferred embodiment, when the core tube of the temperature measuring section is connected to the core tube of the cable-type composite insulation pipe by plug-in connection, the connection is sealed by a high-temperature resistant sealing ring installed in the sealing groove on the outer surface of the core tube at end B.

[0025] As a preferred option, the stepped surface of the temperature measuring cavity of the temperature measuring section is sealed to the temperature measuring cavity cover plate by two inner and outer high-temperature and high-pressure resistant sealing rings designed and installed.

[0026] Preferably, when the temperature measuring short section A and B are connected to the cable-type composite insulation pipe, the temperature measuring bus embedded in the temperature measuring short section and the temperature measuring bus embedded in the cable-type composite insulation pipe are connected through the contact of the conductive ring embedded in the heat insulation bushing.

[0027] Preferably, the temperature measurement module of the temperature measurement sub can simultaneously process the internal and external temperature data measured by the internal and external temperature sensors into digital signals with address codes, and transmit the digital signals to a dedicated ground processor through the temperature measurement bus, thereby realizing the simultaneous measurement of the internal and external temperatures of the measurement sub.

[0028] The advantages of this invention compared to the prior art are as follows:

[0029] (1) Temperature sensors are embedded on the inner and outer surfaces of the temperature measuring cavity of the temperature measuring section, which can simultaneously measure the temperature of the inner and outer sides of the section.

[0030] (2) The temperature measurement module of the temperature measurement section can process the internal and external temperature data into digital signals with address codes, and transmit the digital signals to the ground-based dedicated processor through the temperature measurement bus.

[0031] (3) The temperature measuring section can be installed at any connection position in the buried pipe string of medium-deep geothermal wells, and the measuring points can be arranged flexibly.

[0032] (4) In the buried pipe string of the same medium-deep geothermal well, one or more temperature measuring sections can be installed at different locations to achieve simultaneous temperature measurement of different layers in the medium-deep geothermal well and different depths in the buried pipe string.

[0033] (5) The joints and core tubes of the temperature measuring section are made of materials and steel grades that meet API standards to improve the strength, life and temperature and pressure resistance of the temperature measuring section.

[0034] (6) The thermal insulation bushing of the temperature measuring section is made of alicyclic epoxy fiberglass or polyimide fiberglass, which has a long-term temperature resistance greater than 150℃. It has the characteristics of strong temperature resistance, light weight, high mechanical strength, good electrical insulation and low apparent thermal conductivity.

[0035] (7) The temperature measuring cavity of the temperature measuring section is filled with heat insulation materials such as nano aerogel or ceramic fiber, which has an ultra-low apparent thermal conductivity. It can cut off the heat transfer between the inside and outside of the temperature measuring section, greatly improve the heat insulation effect of the temperature measuring section, make the internal and external temperature measurement more accurate, and significantly improve the heat extraction power of the geothermal well.

[0036] (8) The thermal insulation bushing of the temperature measuring section is embedded with multiple conductive rings and a corresponding number of cable buses that are connected in sequence, so that the temperature measuring section has the function of reliably transmitting temperature measurement data and is not easily damaged. Attached Figure Description

[0037] Figure 1 This is a longitudinal cross-sectional schematic diagram of a geothermal well temperature measurement section according to the present invention;

[0038] Figure 2 This is a partial cross-sectional schematic diagram of a geothermal well temperature measurement section according to the present invention;

[0039] Figure 3 This is an enlarged schematic diagram of part I of a geothermal well temperature measurement section of the present invention;

[0040] Figure 4 This is an enlarged schematic diagram of part II of a geothermal well temperature measurement section according to the present invention.

[0041] In the diagram: 1. Female thread of connector A; 2. Connector A; 3. Inner surface of thermal insulation bushing of connector A; 4. Thermal insulation bushing of connector A; 5. Inner surface of core tube A; 6. Core tube; 7. Weld of outer tube of temperature measuring cavity of connector A; 8. Outer tube of temperature measuring cavity; 9. Weld of core tube of connector A; 10. Thermal insulation material of temperature measuring cavity; 11. Weld of core tube of connector B; 12. Weld of outer tube of temperature measuring cavity of connector B; 13. Connector B; 14. Thermal insulation bushing of connector B; 15. Male thread of connector B; 16. Outer surface of thermal insulation bushing of connector B; 17. Outer surface of core tube B; 18. High-temperature resistant sealing ring; 19. Sealing groove of core tube B; 20. Conductive ring No. 1 of connector B; 21. Conductive ring No. 2 of connector B; 22. Bus wire hole of connector B; 23. Bus No. 1; 24. Bus No. 2; 25. Bus wire hole of connector A; 26. Bus 3; Buses 27 and 4; 28. Conductive ring 1 at end A; 29. ​​Conductive ring 2 at end A; 30. Stepped hole in temperature measuring chamber; 31. Inner ring sealing groove of stepped surface; 32. Fastening threaded hole of cover plate; 33. Outer ring sealing groove of stepped surface; 34. Stepped surface of temperature measuring chamber; 35. Cover plate of temperature measuring chamber; 36. Mounting hole for external temperature sensor; 37. External temperature sensor; 38. Set threaded hole for module; 39. Fastening threaded hole for cover plate. 40. Cover plate fastening stepped hole; 41. A-end connector inner temperature wire hole; 42. Inner temperature sensor mounting hole; 43. Inner temperature sensor; 44. Inner temperature wire No. 1; 45. Inner temperature wire No. 2; 46. Temperature measuring module set screw; 47. Temperature measuring module; 48. Outer temperature wire No. 1; 49. Outer temperature wire No. 2; 50. Temperature measuring module fixing hole; 51. Outer ring sealing ring; 52. Inner ring sealing ring. Detailed Implementation

[0042] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0043] This invention provides a geothermal well temperature measurement short section, which connects to a cable-type composite insulation pipe, such as... Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, the temperature measuring section comprises: A-end connector female thread 1, A-end connector 2, A-end heat insulation bushing inner surface 3, A-end heat insulation bushing 4, core tube A-end inner surface 5, core tube 6, A-end connector temperature measuring cavity outer tube weld 7, temperature measuring cavity outer tube 8, A-end connector core tube weld 9, temperature measuring cavity heat insulation material 10, B-end connector core tube weld 11, B-end connector temperature measuring cavity outer tube weld 12, B-end connector 13, B-end heat insulation bushing 14, B-end connector male thread 15, B-end heat insulation bushing outer surface 16, core tube B-end outer surface 17, high-temperature resistant sealing ring 18, core tube B-end sealing groove 19, B-end No. 1 conductive ring 20, B-end No. 2 conductive ring 21, B-end connector bus wire hole 22, No. 1 bus 23, No. 2 bus 24, A-end connector bus wire hole 2 5. Bus No. 3, 26. Bus No. 4, 27. Conductive Ring No. 1 at End A, 28. Conductive Ring No. 2 at End A, 29. Stepped Hole of Temperature Measuring Chamber, 30. Inner Ring Sealing Groove of Stepped Surface, 31. Fastening Threaded Hole of Cover Plate, 32. Outer Ring Sealing Groove of Stepped Surface, 33. Stepped Surface of Temperature Measuring Chamber, 34. Cover Plate of Temperature Measuring Chamber, 35. Mounting Hole of External Temperature Sensor, 36. External Temperature Sensor, 37. Set Threaded Hole of Module, 38. Fastening Bolt of Cover Plate, 39. Stepped Hole of Cover Plate, 40. Inner Temperature Wire Hole of End A Connector, 41. Mounting Hole of Internal Temperature Sensor, 42. Internal Temperature Sensor, 43. Internal Temperature Wire No. 1, 44. Internal Temperature Wire No. 2, 45. Set Screw of Temperature Measuring Module, 46. Temperature Measuring Module, 47. External Temperature Wire No. 1, 48. External Temperature Wire No. 2, 49. Fixing Hole of Temperature Measuring Module, 50. Outer Ring Sealing Ring, 51. and Inner Ring Sealing Ring, 52.

[0044] In this embodiment, the thermal insulation bushing 4 of the measuring short section at end A is wound and fixed to the outer surface of end A of the core tube 6. After the core tube 6 passes through the inner through hole of end A connector 2, it is welded together at the core tube weld seam 9 of end A connector.

[0045] In this embodiment, the core tube 6 of the measuring section passes through the inner through hole of the B-end connector 13 and is welded together at the core tube weld 11 of the B-end connector. The B-end heat insulation bushing 14 is fixed to the outer surface of the B-end of the core tube 6.

[0046] In this embodiment, the outer tube 8 of the temperature measuring chamber of the measuring section is formed by butt welding of a half-joint tube, and then welded together with the A-end connector 2 at the A-end connector core tube weld 7, and welded together with the B-end connector 13 at the B-end connector core tube weld 12.

[0047] In this embodiment, the outer tube 8 of the temperature measuring cavity of the measuring section is designed with a temperature measuring cavity stepped hole 30. The stepped surface 34 of the temperature measuring cavity stepped hole 30 is designed with an inner ring sealing groove 31, a cover plate fastening threaded hole 32 and an outer ring sealing groove 33.

[0048] In this embodiment, the temperature measuring chamber cover plate 35 of the measuring section is designed with one external temperature sensor mounting hole 36, four module fastening threaded holes 38, and four cover plate fastening stepped holes 40.

[0049] In this embodiment, the cover plate fastening bolt 39 of the measuring section passes through the cover plate fastening stepped hole 40 and is threaded into the cover plate fastening threaded hole 32, and fastens the temperature measuring chamber cover plate 35 to the temperature measuring chamber outer tube 8. The temperature measuring chamber cover plate 35 and the temperature measuring chamber outer tube 8 are sealed by the outer ring sealing ring 51 and the inner ring sealing ring 52.

[0050] In this embodiment, the temperature measuring module 47 of the measuring section is designed with four temperature measuring module fixing holes 50. After the temperature measuring module fixing screw 46 passes through the temperature measuring module fixing hole 50, it is threaded into the module fixing thread hole 38 and fixes the temperature measuring module 47 to the inner surface of the temperature measuring chamber cover plate 35.

[0051] In this embodiment, the external temperature sensor 37 of the measuring section is installed in the external temperature sensor mounting hole 36 and sealed with high temperature and high pressure resistant sealant. The external temperature wire 1 48 and external temperature wire 2 49 connected to the bottom of the external temperature sensor 37 pass through the external temperature sensor mounting hole 36 and are connected to the temperature measuring module 47 to realize the measurement of the external temperature of the measuring section.

[0052] In this embodiment, the internal temperature sensor 43 of the measuring section is installed in the internal temperature sensor mounting hole 42 on the core tube 6 and sealed with high temperature and high pressure resistant sealant. The internal temperature wire 1 44 and internal temperature wire 2 45 connected to the bottom of the internal temperature sensor 43 pass through the internal temperature wire hole 41 of the A-end connector 2 and are connected to the temperature measuring module 47 to realize the measurement of the temperature of the inner center channel of the measuring section.

[0053] In this embodiment, the thermal insulation bushing 4 at end A of the measuring section has embedded bus 3 26, bus 4 27, conductive ring 1 28 at end A, and conductive ring 29 at end A. The inner surface of the conductive rings is exposed and flush with the inner surface 3 of the thermal insulation bushing at end A. Bus 3 26 is connected to conductive ring 1 28 at end A, and bus 4 27 is connected to conductive ring 29 at end A, realizing the conduction and transmission of measurement signals.

[0054] In this embodiment, after the No. 3 bus 26 and No. 4 bus 27 of the measuring section pass through the bus wiring hole 25 of the A-end connector, they are connected to the temperature measuring module 47 inside the temperature measuring cavity. The bus wiring hole 25 of the A-end connector is filled with high-temperature resistant insulating sealant.

[0055] In this embodiment, the B-end thermal insulation bushing 14 of the measuring section has embedded conductive ring 20 (B-end 1), conductive ring 21 (B-end 2), bus 1 (B-end 23), and bus 24 (B-end 2). The outer surface of the conductive rings is exposed and slightly higher than the outer surface 16 of the B-end thermal insulation bushing. Conductive ring 20 (B-end 1) is connected to bus 1 (B-end 23), and conductive ring 21 (B-end 2) is connected to bus 24 (B-end 2), thus realizing the conduction and transmission of measurement signals.

[0056] In this embodiment, after the No. 1 bus 23 and No. 2 bus 24 of the measuring section pass through the bus wiring hole 22 of the B-end connector, they are connected to the temperature measuring module 47 in the temperature measuring cavity. The bus wiring hole 22 of the B-end connector is filled with high-temperature resistant insulating sealant.

[0057] Preferably, in this embodiment, the A-end connector 2 of the measuring section is machined with an A-end connector female thread 1, and the B-end connector 13 is machined with a B-end connector male thread 15, which is used to achieve threaded connection with the cable-type composite insulation pipe string that has a matching size structure.

[0058] Preferably, in this embodiment, the A-end thermal insulation bushing 4 of the measuring short section is designed with an inner surface 3 of the A-end thermal insulation bushing, and the B-end thermal insulation bushing 14 is designed with an outer surface 16 of the B-end thermal insulation bushing, which is used to achieve plug-in connection with the cable-type composite thermal insulation pipe string that has a matching size structure.

[0059] Preferably, in this embodiment, the A end of the core tube 6 of the measuring section is designed with an inner surface 5 of the core tube A end, and the B end is designed with an outer surface 17 of the core tube B end, which is used to realize plug-in connection with the cable-type composite insulation pipe string with matching size structure.

[0060] As a preferred embodiment, the B end of the core tube 6 of the measuring section is designed with two core tube B end sealing grooves 19, and a high temperature resistant sealing ring 18 is designed in the core tube B end sealing groove 19 to ensure that the medium will not leak when plugged in.

[0061] As a preferred embodiment, the stepped inner ring sealing groove 31 and the stepped outer ring sealing groove 33 of the measuring section are respectively designed with a high-temperature and high-pressure resistant outer ring sealing ring 51 and an inner ring sealing ring 52 to ensure good sealing effect when used in a long-term high-temperature and high-pressure environment.

[0062] As a preferred embodiment, the A-end connector 2, the outer tube 8 of the temperature measuring chamber, the B-end connector 13, and the core tube 6 of the measuring section are made of materials and steel grades that meet API standards, thereby improving the strength, lifespan, and temperature and pressure resistance of the temperature measuring section.

[0063] Preferably, in this embodiment, the thermal insulation bushing 4 at end A and the thermal insulation bushing 14 at end B of the measuring section are made of alicyclic epoxy fiberglass or polyimide fiberglass, which have a long-term temperature resistance greater than 150°C. They have the characteristics of strong temperature resistance, light weight, high mechanical strength, good electrical insulation and low apparent thermal conductivity.

[0064] Preferably, in this embodiment, the thermal insulation material 10 of the temperature measuring cavity of the measuring section is selected from thermal insulation materials such as nano-aerogel or ceramic fiber insulation, which have an ultra-low apparent thermal conductivity. It fills the temperature measuring cavity section composed of the A-end connector 2, the outer tube 8 of the temperature measuring cavity, the B-end connector 13 and the core tube 6, and isolates the heat transfer between the inside and outside of the temperature measuring section, thereby greatly improving the thermal insulation effect of the temperature measuring section and making the internal and external temperature measurement results more accurate.

[0065] Preferably, the temperature measurement module 47 of the temperature measurement sub-section in this embodiment can simultaneously process the inner and outer temperature data measured by the inner temperature sensor 43 and the outer temperature sensor 37 into digital signals with address codes, and transmit the digital signals to the ground-based dedicated processor through the temperature measurement bus, so as to realize the simultaneous measurement of the inner and outer temperatures of the measurement sub-section.

[0066] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, equivalent changes, or alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention. This structural design is applicable to the full-size design of measuring subsections.

Claims

1. A geothermal well temperature measurement short section, characterized in that, include: A core tube (6) has its two ends passing through an A-end connector (2) and a B-end connector (13) respectively; an A-end heat insulation bushing (4) is provided between the core tube (6) and the A-end connector (2), and a B-end heat insulation bushing (14) is provided between the core tube (6) and the B-end connector (13); a temperature measuring chamber outer tube (8) is fitted around the core tube (6), and its two ends are connected to the A-end connector (2) and the B-end connector (13) respectively; a temperature measuring chamber heat insulation material (10) is provided between the temperature measuring chamber outer tube (8) and the core tube (6); a temperature measuring chamber stepped hole (30) is provided on the temperature measuring chamber outer tube (8), and several sealing grooves are provided on the stepped surface of the temperature measuring chamber stepped hole (30); the temperature measuring chamber outer tube (8) is also provided with a temperature measuring chamber cover plate (35) that cooperates with the temperature measuring chamber stepped hole (30); the temperature measuring chamber outer tube (8) has a heat measuring chamber stepped hole (30) and a heat measuring chamber stepped hole (30); the temperature measuring chamber outer tube (8) has a heat measuring chamber stepped hole (2) and a B-end connector (13) respectively; the temperature measuring chamber outer tube (6 ... A temperature measuring module (47) is provided on the inner surface of the cavity cover plate (35), and an external temperature sensor (37) connected to the temperature measuring module (47) is provided on the outer surface of the temperature measuring cavity cover plate (35); an internal temperature sensor mounting hole (42) for installing an internal temperature sensor (43) is provided on the core tube (6), and the internal temperature sensor (43) is connected to the temperature measuring module (47) through a wire provided in the heat insulation material (10) of the temperature measuring cavity; an inner ring sealing groove (31) and an outer ring sealing groove (33) are provided on the stepped surface of the stepped hole (30) of the temperature measuring cavity; the temperature measuring cavity cover plate (35) is a T-shaped structure, and the temperature measuring module (47) is installed on the protruding side of the T-shaped structure, and the two sides of the T-shaped structure are fixed to the outer tube (8) of the temperature measuring cavity by cover plate fastening bolts (39); The heat insulation bushing (4) at end A is embedded with bus 3 (26), bus 4 (27), conductive ring 1 (28) at end A and conductive ring 2 (29) at end A. Bus 3 (26) is connected to conductive ring 1 (28) at end A and bus 4 (27) is connected to conductive ring 2 (29) at end A. After passing through the bus wire hole (25) at end A, bus 3 (26) and bus 4 (27) are connected to the temperature measuring module (47) in the temperature measuring cavity to realize the processing and transmission of digital signals. The A-end connector (2) is machined with an A-end connector female thread (1), and the B-end connector (13) is machined with a B-end connector male thread (15), which is used to achieve threaded connection with the cable-type composite insulation pipe string that has a matching size structure.

2. The geothermal well temperature measurement short section according to claim 1, characterized in that, The heat insulation bushing (4) at end A is wound and fixed on the outer surface of end A of the core tube (6). After the core tube (6) passes through the inner through hole of end A connector (2), it is welded to one end of end A connector (2). The heat insulation bushing (14) at the B end is fixed to the outer surface of the B end of the core tube (6). The core tube (6) passes through the inner through hole of the B end connector (13) and is welded to one end of the B end connector (13).

3. The geothermal well temperature measurement subsection according to claim 1, characterized in that, The outer tube (8) of the temperature measuring chamber is formed by butt welding of a semi-assembled tube, and the two ends of the outer tube (8) of the temperature measuring chamber are welded to the A-end connector (2) and the B-end connector (13) respectively.

4. The geothermal well temperature measurement short section according to claim 3, characterized in that, The heat insulation bushing (14) at the B end is embedded with a conductive ring 1 (20), a conductive ring 2 (21), a bus 1 (23), and a bus 2 (24). The conductive ring 1 (20) at the B end is connected to the bus 1 (23), and the conductive ring 2 (21) at the B end is connected to the bus 2 (24). The bus 1 (23) and the bus 2 (24) pass through the bus wire hole (22) at the B end connector and are connected to the temperature measuring module (47) in the temperature measuring cavity to realize the processing and transmission of digital signals.

5. A geothermal well temperature measurement subsection according to claim 4, characterized in that, The diameters of the No. 1 conductive ring (20) and No. 2 conductive ring (21) at end B are larger than the diameters of the No. 1 conductive ring (28) and No. 2 conductive ring (29) at end A, and the No. 1 conductive ring (20) and No. 2 conductive ring (21) at end B can be interference-fitted with the No. 1 conductive ring (28) and No. 2 conductive ring (29) at end A of the adjacent geothermal well temperature measuring section, respectively.

6. The geothermal well temperature measurement subsection according to claim 1, characterized in that, The thermal insulation material (10) of the temperature measuring cavity is a nano-aerogel thermal insulation material or a ceramic fiber thermal insulation material with an ultra-low apparent thermal conductivity.

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