Deep well temperature measuring device and deep well temperature measuring method
By combining a color-changing temperature sensor and a pressure tank with an automatic pressure relief valve, the mechanical design solves the problem of existing downhole temperature monitoring devices being prone to failure under high temperature and high pressure environments. This achieves accuracy and stability in deep well temperature measurement, reducing the risk of failure and maintenance difficulty.
Patent Information
- Application Number
- CN202511742408.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-25
- Publication Date
- 2026-02-10
AI Technical Summary
Existing downhole temperature monitoring devices are prone to failure in high-temperature and high-pressure environments, and their temperature resistance limit is usually no more than 200°C, which cannot meet the temperature measurement requirements of deep wells.
The mechanical design incorporates a color-changing temperature sensor and a pressure tank combined with an automatic pressure relief valve. The color-changing temperature sensor measures temperature through color changes, while the pressure tank and automatic pressure relief valve work together to provide a rapid response under high temperature and high pressure, preventing electronic component failure.
It achieves accurate temperature measurement in the high temperature and high pressure environment of deep wells. It has a simple structure, is recyclable, and has low cost. The mechanical structure has a low probability of wear and aging, and the response speed is fast. It avoids the failure of electronic components in extreme environments and improves the environmental adaptability and stability of the device.
Smart Images
Figure CN121497319A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of drilling measurement instruments, and in particular to a deep well temperature measurement device and method. Background Technology
[0002] Geological drilling provides access to a wealth of Earth science information deep within the Earth's crust, including the Earth's formation, evolution, structure, and composition. Temperature has a particularly significant impact on geological drilling; accurate temperature data is crucial for optimizing drilling fluid performance, extending drill bit life, ensuring cementing quality, assessing formation stability, interpreting logging data, and selecting appropriate downhole tools and equipment. Therefore, temperature monitoring is essential in geological drilling.
[0003] However, existing downhole temperature monitoring in China mainly relies on electronic temperature sensing devices. The upper limit of the temperature resistance of these devices is usually no more than 200°C, and they are prone to failure in high temperature and high pressure environments. Summary of the Invention
[0004] The purpose of this invention is to provide a deep well temperature measurement device and method to solve the problems existing in the prior art. It can be used for accurate temperature measurement in the high temperature and high pressure environment of deep wells, and has a simple structure, is recyclable, and has low cost.
[0005] To achieve the above objectives, the present invention provides the following solution: This invention provides a deep well temperature measurement device, comprising a pipe body, a first temperature measurement module, a second temperature measurement module, a ground pressure detection element, and a ground temperature detection element. The pipe body has a sealable accommodating space for accommodating the first and second temperature measurement modules. The first temperature measurement module includes a color-changing temperature sensor that changes color with changes in ambient temperature and can be removed from the accommodating space. The second temperature measurement module includes a pressure tank and an automatic pressure relief valve. The automatic pressure relief valve is located at the opening of the pressure tank and is used to automatically release pressure when the pressure inside the pressure tank reaches a preset threshold. The ground pressure detection element can detect the pressure inside the pressure tank at the ambient ground temperature. The ground temperature detection element can detect the ambient ground temperature.
[0006] In some embodiments, a first housing and a second housing are axially arranged sequentially inside the tube. The first housing is used to fix the first temperature measuring module, and the second housing is used to fix the second temperature measuring module. The first end of the first housing is detachably and fixedly connected to the first end of the tube, the second end of the first housing is detachably and fixedly connected to the first end of the second housing, and the second end of the second housing is detachably and fixedly connected to the second end of the tube.
[0007] In some embodiments, the first temperature measuring module further includes a third housing and a fixing ring. The outer wall of the third housing has at least one slot, in which the color-changing temperature measuring element can be placed. The fixing ring can be sleeved on the outer wall of the third housing and press the color-changing temperature measuring element located in the slot.
[0008] In some embodiments, the pressure tank is provided with an automatic pressure relief valve at one end and an air inlet at the other end, the air inlet being used to fill the pressure tank with gas.
[0009] In some embodiments, the second housing is provided with a plurality of bolts at equal intervals around its circumference, the bolts being able to pass through the outer wall of the tube to securely connect the pressure tank to the tube.
[0010] In some embodiments, the first housing includes a first housing body and a first end cap. The first housing body is used to fix the first temperature measuring module inside. The first end cap is used to seal and connect to one end opening of the first housing body and is threaded to the first end of the tube. The other end of the first housing body is threaded to one end of the second housing.
[0011] In some embodiments, the second housing includes a second housing body and a second end cap. The interior of the second housing body is used to fix the second temperature measuring module. The second end cap is used to seal and connect to one end opening of the second housing body and is threadedly connected to one end of the first housing body. The other end of the second housing body is threadedly connected to the second end of the tube.
[0012] In some embodiments, the color-changing temperature measuring element includes 10 independent color-changing cell units spaced apart along a first direction. Each color-changing cell unit can change color within a preset different temperature range. The first direction is parallel to the axial direction of the first temperature measuring module.
[0013] In some embodiments, the tube body, the first housing, the second housing, and the third housing are all made of alloy steel.
[0014] The present invention also provides a deep well temperature measurement method based on a deep well temperature measurement device, comprising the following steps: filling the pressure tank with gas to a preset threshold pressure of the pressure relief valve. And record the ground ambient temperature at that time. The pressure tank volume V; after placing the first temperature measuring module and the second temperature measuring module into the pipe body, the deep well temperature measuring device is lowered into the well to the target depth and left to stand for a preset time; the deep well temperature measuring device is taken out, and the color-changing temperature measuring element is compared with a pre-recorded color temperature comparison table to determine the range of the downhole temperature; wait for the pressure tank temperature to recover to the surface temperature. At that time, the pressure inside the pressure tank was measured. According to the equation It can be deduced that the downhole temperature .
[0015] The present invention achieves the following technical effects compared to the prior art: This invention comprises a pipe body, a first temperature measuring module, a second temperature measuring module, a surface pressure detection element, and a surface temperature detection element. The first temperature measuring module uses a color-changing thermocouple as the temperature sensing element. It achieves temperature measurement through its own physical property of changing color with temperature changes, without relying on any electronic sensors or signal transmission components. This allows operators to quickly compare the color temperature with a color-temperature reference table to determine the downhole temperature range, requiring no complex equipment and simplifying operation. The second temperature measuring module uses a pressure tank and an automatic pressure relief valve in mechanical coordination. When the temperature rises rapidly, the pressure inside the pressure tank rises synchronously, and the automatic pressure relief valve can quickly release pressure. Compared to electronic protection systems, the response speed is faster, effectively avoiding safety risks caused by delays. Furthermore, the mechanical structure has a lower probability of wear and aging than electronic components, resulting in higher fault tolerance and a longer service life. Both the first and second temperature measuring modules adopt a passive, mechanical design, eliminating the need for additional electronic control systems, power supply systems, or data transmission systems. This simplifies the overall circuit layout and system integration complexity, reduces potential failure points, further improves the operational stability of the device, and reduces the difficulty of installation, commissioning, and maintenance. Meanwhile, the sealed space of the tube can provide stable protection for the first and second temperature measuring modules, ensuring the normal operation of temperature measurement. The tube, the first temperature measuring module, and the second temperature measuring module are all suitable for high temperature and high pressure conditions, thus effectively avoiding the problems of aging, short circuit, and failure of electronic components in extreme environments. This makes the device highly adaptable to the environment and stable in the complex environment of deep well high temperature and high pressure, and less prone to failure. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 This is a cross-sectional view of a deep well temperature measuring device in one embodiment of Example 1; Figure 2 This is a schematic diagram of the deep well temperature measuring device in one embodiment of Example 1; Figure 3 This is a schematic diagram of the structure of the first temperature measuring module in one embodiment of Example 1; Figure 4 This is a schematic diagram of the structure of the first temperature measuring module in one embodiment of Example 1; Figure 5 This is a schematic diagram of the pressure tank in one embodiment of Example 1; Figure 6 for Figure 5 Sectional view of the pressure tank (AA section).
[0018] Wherein: 1-First end of the tube body; 2-First end cap; 3-First temperature measuring module; 4-First housing; 5-Second housing; 6-Second temperature measuring module; 7-Pressure tank; 8-Second end cap; 9-Second end of the tube body; 10-Elastic washer; 11-Air inlet; 12-Automatic pressure relief valve; 13-Tube body; 21-Rod; 22-Adjusting ring; 23-Spring; 32-Elastic retaining ring; 33-Slot. Detailed Implementation
[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0021] Example 1 This embodiment provides a deep well temperature measurement device, such as... Figure 1-2As shown, the device includes a pipe body 13, a first temperature measuring module 3, a second temperature measuring module 6, a ground pressure detection element, and a ground temperature detection element. The pipe body 13 has a sealable accommodating space for accommodating the first temperature measuring module 3 and the second temperature measuring module 6. The first temperature measuring module 3 includes a color-changing thermometer that changes color with the ambient temperature and can be removed from the accommodating space. The second temperature measuring module 6 includes a pressure tank 7 and an automatic pressure relief valve 12. The automatic pressure relief valve 12 is located at the opening of the pressure tank 7 and is used to automatically release pressure when the pressure inside the pressure tank 7 reaches a preset threshold. The ground pressure detection element can detect the pressure inside the pressure tank 7 at the ground ambient temperature. The ground temperature detection element can detect the ground ambient temperature. This embodiment uses a pipe body 13, a first temperature measuring module 3, a second temperature measuring module 6, a ground pressure detection element, and a ground temperature detection element to detect the ground ambient temperature. The device comprises three modules: Block 3, the second temperature measuring module 6, and surface pressure and temperature sensors. The first temperature measuring module 3 uses a color-changing thermocouple as its sensing element. This thermocouple changes color with temperature, eliminating the need for electronic sensors or signal transmission components. It allows operators to quickly compare the color temperature to a color-temperature chart to determine the downhole temperature range, requiring no complex equipment and simplifying operation. The second temperature measuring module 6 uses a mechanical connection between a pressure tank 7 and an automatic pressure relief valve 12. When the temperature rises rapidly, the pressure in the pressure tank 7 rises synchronously, and the automatic pressure relief valve 12 quickly releases pressure. Compared to electronic protection systems, this provides a faster response and effectively avoids safety risks caused by delays. Furthermore, the mechanical structure has a lower probability of wear and aging than electronic components, resulting in higher fault tolerance and a longer service life. Both the first and second temperature measuring modules 3 and 6 employ a passive, mechanical design, eliminating the need for additional electronic control, power supply, or data transmission systems. This simplifies the overall circuit layout and system integration complexity, reduces potential failure points, further improves the device's operational stability, and lowers the difficulty of installation, commissioning, and maintenance. Meanwhile, the sealed space of the tube body 13 can provide stable protection for the first temperature measuring module 3 and the second temperature measuring module 6, ensuring that the temperature measuring work is carried out normally. Moreover, the tube body 13, the first temperature measuring module 3, and the second temperature measuring module 6 are all suitable for high temperature and high pressure conditions, thereby effectively avoiding the problems of electronic components aging, short circuits, and failures in extreme environments. This makes the device have strong environmental adaptability and working stability in the complex environment of deep well high temperature and high pressure, and it is not easy to fail.
[0022] In some implementations of this embodiment, such as Figure 3-4As shown, a first housing 4 and a second housing 5 are axially arranged inside the tube body 13. The first housing 4 is used to fix the first temperature measuring module 3, and the second housing 5 is used to fix the second temperature measuring module 6. The first end of the first housing 4 is detachably fixed to the first end 1 of the tube body, the second end of the first housing 4 is detachably fixed to the first end of the second housing 5, and the second end of the second housing 5 is detachably fixed to the second end 9 of the tube body. The detachable fixed connection between the first housing 4 and the first end 1 of the tube body and the second housing 5, as well as the detachable fixed connection between the second housing 5 and the second end 9 of the tube body, allows the first temperature measuring module 3 and the second temperature measuring module 6 to be removed from the tube body 13 independently or as a whole. When the temperature measuring module malfunctions or needs calibration or upgrade, it is not necessary to disassemble the entire tube body 13 structure; only the connection parts of the corresponding housings need to be disassembled, reducing maintenance difficulty, minimizing downtime, and improving the operation and maintenance efficiency of the equipment.
[0023] In some embodiments of this example, the first temperature measuring module 3 further includes a third housing and a fixing ring. The outer wall of the third housing has at least one slot 33, in which the color-changing temperature measuring element can be placed. The fixing ring can be sleeved on the outer wall of the third housing and press the color-changing temperature measuring element located in the slot 33. The color-changing temperature measuring element can be directly placed into the slot 33 and then pressed by the fixing ring to complete the assembly. No professional tools or complicated operations are required, which greatly shortens the assembly time, reduces labor costs, and facilitates subsequent disassembly, maintenance or replacement, thus improving operational efficiency. The fixing ring is an elastic retaining ring, and its material is selected from corrosion-resistant and wear-resistant materials suitable for high temperature and high pressure environments, such as polytetrafluoroethylene reinforced composite materials. It can maintain structural stability under extreme working conditions in deep wells and avoid the color-changing temperature measuring element from loosening or falling off due to material failure, further ensuring the reliability of the temperature measuring process.
[0024] In some implementations of this embodiment, such as Figure 5-6 As shown, pressure tank 7 is equipped with an automatic pressure relief valve 12 at one end and an air inlet 11 at the other end. The air inlet 11 is used to fill pressure tank 7 with gas. Gas is pre-filled into pressure tank 7 through air inlet 11 at the pressure relief valve opening pressure at the surface, and the surface temperature and tank volume are recorded. The deep well temperature measuring device is then lowered into the wellbore along with the drill string. As the downhole temperature rises, the gas expands, opening the automatic pressure relief valve 12. Once the temperature stabilizes at the target temperature, the drill string is pulled back to the surface. After pressure tank 7 returns to the surface temperature, the pressure inside pressure tank 7 is measured. The downhole temperature can be calculated. The device has a simple structure, low cost, and is reusable. It is suitable for accurate temperature measurement in high-temperature and high-pressure environments in deep wells. Simultaneously, the automatic pressure relief valve 12 can quickly open to release pressure, preventing damage or failure of pressure tank 7 due to overpressure, ensuring the safety of the device in extreme high-temperature and high-pressure environments. The pressure tank 7 is made of high-temperature, corrosion-resistant, and pressure-resistant materials, such as high-temperature alloys and high-strength ceramic matrix composites.
[0025] In some embodiments of this example, the second housing 5 is provided with multiple bolts at equal intervals in the circumference. The bolts can pass through the outer wall of the tube 13 to fix the pressure tank 7 to the tube 13. The equal interval design of the bolts allows the weight of the pressure tank 7 and the vibration load during operation to be evenly transmitted to the tube 13, avoiding tube deformation, bolt loosening or cracking of the second housing 6 caused by local stress concentration. At the same time, the multi-point uniform fixation can limit the radial and circumferential displacement of the pressure tank 7, and can maintain a stable connection even under high-frequency vibration and high-pressure conditions, preventing the pressure tank 7 from shifting, tilting or even falling off, and significantly improving the structural reliability.
[0026] In some embodiments of this example, the first housing 4 includes a first housing body and a first end cap 2. The first housing body is used to fix the first temperature measuring module 3 inside. The first end cap 2 is used to seal the opening at one end of the first housing body and is threaded to the first end of the tube 13. The other end of the first housing body is threaded to one end of the second housing 5. The first housing 4 is threaded to the tube 13 through the first end cap 2 and to the second housing 5 through the first housing body. The first housing 4 has a compact axial layout, and the connection part is located at the end of the first housing 4. This can achieve precise axial docking of the components inside the tube 13, avoid occupying extra radial space inside the tube 13, and avoid interference with components such as the first temperature measuring module 5, the second temperature measuring module 6, and the pressure tank 7. At the same time, the axial force characteristics of the threaded connection can avoid generating extra radial stress on the side wall of the tube 13, protecting the integrity of the tube structure. This is especially suitable for scenarios with small tube diameter and compact internal space.
[0027] In some embodiments of this example, the second housing 5 includes a second housing body and a second end cap 8. The second housing body is used to fix the second temperature measuring module 6 inside. The second end cap 8 is used to seal the opening at one end of the second housing body and is threadedly connected to one end of the first housing body. The other end of the second housing body is threadedly connected to the second end of the tube 13. The second housing 5 is threadedly connected to the tube 13 through the second end cap 8 and to the first housing 5 through the second housing body. The axially compact layout, with the connection part located at the end of the second housing 5, enables precise axial docking of the components inside the tube 13, avoids occupying additional radial space inside the tube 13, and does not interfere with components such as the first temperature measuring module 3, the second temperature measuring module 6, and the pressure tank 7. At the same time, the axial force characteristics of the threaded connection can avoid generating additional radial stress on the sidewall of the tube 13, protecting the structural integrity of the tube, and is especially suitable for scenarios with small tube diameter and compact internal space.
[0028] In some embodiments of this example, the color-changing temperature measuring device includes 10 independent color-changing cells spaced apart along a first direction. Each color-changing cell can change color within a preset temperature range. The first direction is parallel to the axis of the first temperature measuring module 3. The color changes of the 10 independent color-changing cells are intuitively visible. After the operator removes the color-changing temperature measuring device from the well, they can quickly compare the number of color changes and their corresponding positions with a preset temperature range reference table by directly observing the number of color changes in the cells. Without the need for complex equipment analysis or data processing, the operator can quickly locate the temperature range in the well, significantly improving the efficiency of on-site temperature measurement operations and reducing reliance on the operator's professional skills. The temperature ranges of the ten cells are -20℃ to 10℃, 10℃ to 40℃, 40℃ to 70℃, 70℃ to 100℃, 100℃ to 140℃, 140℃ to 180℃, 180℃ to 220℃, 220℃ to 260℃, 260℃ to 300℃, and 300℃ to 350℃. The color-changing temperature measuring element is model Thermax temperature measuring paper.
[0029] In some embodiments of this example, the tube body 13, the first shell 4, the second shell 5, and the third shell are all made of alloy steel. Alloy steel has the characteristics of high temperature resistance and high pressure resistance, and can be used in the high temperature and high pressure environment of deep wells, thereby ensuring temperature measurement accuracy.
[0030] Example 2 This embodiment also provides a deep well temperature measurement method based on the deep well temperature measurement device of Embodiment 1, including the following steps: inflating the pressure tank 7 to the preset threshold pressure of the pressure relief valve. And record the ground ambient temperature at that time. The pressure tank 7 has a volume V; after placing the first temperature measuring module 3 and the second temperature measuring module 6 into the pipe body 13, the deep well temperature measuring device is lowered into the well to the target depth and left to stand for a preset time; the deep well temperature measuring device is taken out, and the color-changing temperature measuring element is compared with the pre-recorded color temperature comparison table to determine the range of the downhole temperature; wait for the temperature of the pressure tank 7 to return to the surface temperature. At that time, the pressure inside pressure tank 7 was measured. According to the equation It can be deduced that the downhole temperature ; This embodiment uses a pipe body 13, a first temperature measuring module 3, a second temperature measuring module 6, a ground pressure detection element, and a ground temperature detection element. The first temperature measuring module 3 uses a color-changing temperature measuring element, which achieves temperature measurement by changing color with temperature through its own physical properties. It does not rely on any electronic sensors or signal transmission components, and it is convenient for operators to quickly compare the color temperature reference table to determine the downhole temperature range. It does not require complex equipment support and is easy to use. The second temperature measuring module 6 uses the mechanical cooperation of the pressure tank 7 and the automatic pressure relief valve 12. When the temperature rises rapidly, the pressure in the pressure tank 7 rises synchronously, and the automatic pressure relief valve 12 can quickly release pressure. Compared with the electronic protection system, the response speed is faster and can effectively avoid safety risks caused by delay. At the same time, the wear and aging probability of the mechanical structure is lower than that of electronic components, the fault tolerance is higher, and the service life is longer. Both the first temperature measuring module 3 and the second temperature measuring module 6 adopt a passive, mechanical design, eliminating the need for additional electronic control, power supply, or data transmission systems. This simplifies the overall circuit layout and system integration complexity, reduces potential failure points, and further enhances the device's operational stability. It also lowers the difficulty of installation, debugging, and maintenance. Furthermore, the sealed enclosure of the tube body 13 provides stable protection for the first and second temperature measuring modules 3 and 6, ensuring normal temperature measurement operation. All three modules are suitable for high-temperature and high-pressure conditions, effectively preventing the aging, short-circuiting, and failure of electronic components in extreme environments. This gives the device strong environmental adaptability and operational stability in the complex high-temperature and high-pressure environment of deep wells, making it less prone to failure. Explanation of the principle of the first temperature measuring module 3: In the surface environment, the color-changing temperature measuring element is first placed into the slot 33 of the first temperature measuring module 3. The color-changing temperature measuring element is initially colored. Then, the first temperature measuring module 3 and the second temperature measuring module 6 are placed into the first housing 4 and the second housing 5, respectively. The second housing 5 and the first housing 4 are then placed into the tube 13 at the same time. The first housing 4 is tightened to the first end 1 of the tube, the first housing 4 is tightened to the second housing 5, and the second housing 5 is tightened to the second end 9 of the tube. After the deep well temperature measuring device is lowered into the well with the drill pipe to the target depth and left to stand for a sufficient time, the temperature of the color-changing temperature measuring element tends to be consistent with the downhole temperature, and the color-changing temperature measuring element changes color accordingly. By comparing the retrieved color-changing temperature measuring element with the pre-recorded color-temperature comparison table, the range of downhole temperature can be determined.
[0031] Explanation of the principle of the second temperature measuring module 6: The pressure tank 7 is inflated to the pressure required to open the pressure relief valve on the ground. And record the ground temperature at that time. and the gas tank volume V; then, it was run downhole to the depth to be measured, and the downhole ambient temperature was... When the pressure is increased, the gas inside the pressure tank 7 expands and periodically actuates the automatic pressure relief valve 12 to maintain a constant pressure inside the pressure tank 7. After the temperature stabilizes, it will be lifted back to the ground, and the temperature of pressure tank 7 will return to the ground temperature. At that time, the pressure inside the pressure tank 7 was measured at the air inlet 11 using a pressure detector. According to the ideal gas equation: Because the deep well temperature measuring device enters the well... The downhole temperature was obtained. .
[0032] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.
Claims
1. A deep well temperature measuring device, characterized in that: It includes a pipe body, a first temperature measuring module, a second temperature measuring module, a ground pressure detection device, and a ground temperature detection device. The pipe body has a sealable accommodating space for accommodating the first temperature measuring module and the second temperature measuring module. The first temperature measuring module includes a color-changing temperature measuring element, which can change color with the ambient temperature and can be removed from the receiving space. The second temperature measuring module includes a pressure tank and an automatic pressure relief valve. The automatic pressure relief valve is located at the opening of the pressure tank and is used to automatically release pressure when the pressure inside the pressure tank reaches a preset threshold. The ground pressure detection device can detect the pressure inside the pressure tank at ground ambient temperature; The ground temperature detection device can detect the ground ambient temperature.
2. The deep well temperature measuring device according to claim 1, characterized in that: The tube body is provided with a first shell and a second shell in axial order. The first shell is used to fix the first temperature measuring module, and the second shell is used to fix the second temperature measuring module. The first end of the first shell is detachably fixed to the first end of the tube body, the second end of the first shell is detachably fixed to the first end of the second shell, and the second end of the second shell is detachably fixed to the second end of the tube body.
3. The deep well temperature measuring device according to claim 2, characterized in that: The first temperature measuring module also includes a third housing and a fixing ring. The outer wall of the third housing has at least one slot, in which the color-changing temperature measuring element can be placed. The fixing ring can be sleeved on the outer wall of the third housing and press the color-changing temperature measuring element located in the slot.
4. The deep well temperature measuring device according to claim 1, characterized in that: The pressure tank is equipped with an automatic pressure relief valve at one end and an air inlet at the other end, which is used to fill the pressure tank with gas.
5. The deep well temperature measuring device according to claim 2, characterized in that: The second housing is provided with a plurality of bolts at equal intervals around its circumference. The bolts can pass through the outer wall of the tube to fix the pressure tank to the tube.
6. The deep well temperature measuring device according to claim 2, characterized in that: The first housing includes a first housing body and a first end cap. The first housing body is used to fix the first temperature measuring module inside. The first end cap is used to seal and connect to one end opening of the first housing body and is threaded to the first end of the tube. The other end of the first housing body is threaded to one end of the second housing.
7. The deep well temperature measuring device according to claim 2, characterized in that: The second housing includes a second housing body and a second end cap. The interior of the second housing body is used to fix the second temperature measuring module. The second end cap is used to seal and connect to one end opening of the second housing body and is threaded to one end of the first housing body. The other end of the second housing body is threaded to the second end of the tube.
8. The deep well temperature measuring device according to claim 1, characterized in that: The color-changing temperature measuring element includes 10 independent color-changing units spaced apart along a first direction. Each color-changing unit can change color within a preset temperature range. The first direction is parallel to the axis of the first temperature measuring module.
9. The deep well temperature measuring device according to claim 3, characterized in that: The tube body, the first shell, the second shell, and the third shell are all made of alloy steel.
10. A deep well temperature measurement method based on the deep well temperature measurement device according to any one of claims 1-9, characterized in that: Includes the following steps: Inflate the pressure tank to the preset threshold pressure of the pressure relief valve. And record the ground ambient temperature at that time. and the volume V of the pressure tank; After placing the first temperature measuring module and the second temperature measuring module into the pipe body, the deep well temperature measuring device is lowered into the well to the target depth and left to stand for a preset time. Take out the deep well temperature measuring device, compare the color-changing temperature measuring element with the pre-recorded color temperature comparison table, and determine the range of the downhole temperature. Wait until the temperature of the pressure tank returns to the ground temperature At that time, the pressure inside the pressure tank was measured. ; According to the equation It can be deduced that the downhole temperature .