Shaft leak hunting tool and leak hunting method for producing well
By using pressure sensors in oil production wells to monitor the pressure changes at the upper and lower ends of the wellbore, the problems of complex detection process, high cost and poor accuracy in the prior art are solved, and a simple and reliable leakage point detection effect is achieved.
Patent Information
- Application Number
- CN202510219754.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-26
- Publication Date
- 2025-04-08
AI Technical Summary
When detecting the leakage point of the oil production well casing, the process is complicated, the equipment cost is high, the technical requirements for the operators are high, and the detection accuracy is poor when the leakage is small.
A wellbore leak measurement tool for oil production wells is provided, including an upper joint assembly, a power system assembly, a rod body component and a hard tube. The pressure changes at the upper and lower ends of the wellbore are monitored by a pressure sensor to determine whether the well section is leaked.
It has achieved simplification of the inspection process, reduced equipment and maintenance costs, reduced technical requirements for operators, and can accurately detect large and small leakages, making the results more reliable.
Smart Images
Figure CN119777850A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of petroleum well logging, and in particular to a wellbore leak detection tool and a leak detection method for an oil production well. Background Art
[0002] For oil fields that are being developed in large quantities in China, as time goes on, some oil casings may develop cracks, holes in the formation, and other natural factors that may cause the wellbore to be disconnected, perforated, or ruptured due to poor geological conditions, excessive bottom hole pressure, or chemical corrosion.
[0003] During the oil well logging process, if there is a leak in the wellbore, it will not only affect the drilling efficiency, but serious well leakage may lead to blowout or well collapse, endangering the drilling equipment, and may also pose a threat to the environment and personnel safety. In addition, well leakage may also cause irreversible damage to the production layer and affect the efficiency of oil resource extraction. Therefore, timely discovery and determination of the depth of the leak is of great significance for the remediation and maintenance of oil and gas wells.
[0004] At present, there are many methods for detecting leaks in oil well casings at home and abroad, such as the well temperature and noise combined logging method: this method determines the location of the leak by detecting the well temperature change and the noise level. In the case of a large gas well leakage, this method is effective and can effectively detect the leak. However, in the case of a small leakage, the characteristics of the well temperature change and the noise level are not obvious, which can easily lead to inaccurate leak detection or even missed detection. At the same time, this method has high requirements on the accuracy of the detection equipment, and the equipment cost and maintenance cost are relatively high.
[0005] Annular fluid activity measurement method: This method detects leaks by monitoring the activity of the annular fluid. When the gas well leakage is small, this method can detect the leak location more accurately, and the test space range is larger. However, the detection results of this method are easily affected by the properties of the annular fluid, the flow state, and other interference factors in the well. For example, when the annular fluid has a complex flow state or contains impurities, it may lead to misjudgment of the fluid activity, thereby affecting the accuracy of leak detection. In addition, the detection process of this method is relatively complicated and requires professional operators to operate and analyze.
[0006] Induction logging: This method detects leaks by measuring formation resistivity. Induction logging (IL) determines the resistivity of the formation through the main current (I0) and the potential difference (△U) in the main current field, thereby determining the location of the leak. Although induction logging is suitable for situations where formation resistivity needs to be accurately measured, this method can only detect areas where formation resistivity changes. For some leaks that do not affect formation resistivity, such as tiny cracks in the casing, it may not be accurately detected. In addition, induction logging equipment is expensive and requires a high level of technical skills from the operator, which is subject to certain limitations in practical applications.
[0007] Each of these methods has its own advantages and disadvantages, and the selection of the appropriate method needs to be determined based on the specific situation and the characteristics of the leak point. For example, the temperature-noise combined logging method works better when the leak volume is large, while the annular fluid activity determination method is more effective when the leak volume is small. Induction logging is suitable for situations where accurate measurement of formation resistivity is required.
[0008] Therefore, the present invention provides a wellbore leak detection tool and a leak detection method for an oil production well. Summary of the invention
[0009] The purpose of the present invention is to provide a wellbore leak detection tool and a leak detection method for oil wells, so as to overcome the shortcomings of the prior art that the detection process is relatively complicated, the equipment cost and maintenance cost are relatively high, and the technical level requirements for operators are high.
[0010] In order to achieve the above object, the present invention provides the following technical solutions: On the one hand, the present invention provides a wellbore leak detection tool for an oil production well, comprising an upper joint assembly, a power system assembly, a rod body component and a hard pipe; the upper joint assembly comprises a docking valve and a first pressure sensor is arranged on the upper joint assembly, the lower end of the upper joint assembly is connected to the rod body component and the upper joint assembly is connected to the power system assembly; The power system component includes a power device, a screw device and a pressurizing device; the power device, the screw device and the pressurizing device are connected in sequence and embedded in the rod body component as a whole and fixedly connected; the docking valve is connected to one end of the first hard pipe through the pipeline inside the upper joint assembly, and the other end of the first hard pipe is connected to the pressurizing device. A second pressure sensor is provided on the pressurizing device, and a wire of the second pressure sensor is passed through the second hard pipe.
[0011] Furthermore, the power device includes a DC motor with a reducer and a motor housing; the output end of the DC motor is connected to the screw device through a coupling; and a plug is installed at the input end of the DC motor.
[0012] Further, the screw device includes a thrust ball bearing, a needle bearing, a limit cylinder, a first limit switch, a trapezoidal screw, an intermediate cylinder, a push-pull rod limit block and a second limit switch; The screw device includes a limit cylinder, a first limit switch, a trapezoidal screw, an intermediate cylinder, a push-pull rod, a limit block and a second limit switch; One end of the power housing is connected to the plug, and the other end is connected to the pressurizing device. The upper end of the bearing housing is connected to the motor housing, and the lower end is connected to the limit cylinder. The lower end of the limit cylinder is connected to the intermediate cylinder. The trapezoidal lead screw is arranged inside the limit cylinder, and the upper end of the trapezoidal lead screw is connected to the output end of the DC motor through a coupling. The lower end of the trapezoidal lead screw is connected to the upper end of the push-pull rod, and the lower end of the push-pull rod is connected to the pressurizing device. The upper and lower side walls of the limit cylinder are both provided with a slot, the upper end of the slot of the limit cylinder is provided with a first limit switch, the lower end of the slot of the limit cylinder is provided with a second limit switch, and an anti-rotation key is provided on the slot. The limit cylinder and the trapezoidal lead screw make reciprocating motion in the slot through the anti-rotation key to provide push-pull force for the pressurizing device.
[0013] Further, the pressurizing device includes a piston cylinder, a piston, a first one-way valve, a second pressure sensor and a second one-way valve; The push-pull rod extends to the inside of the intermediate cylinder and connects to the piston. The piston is slidably arranged inside the piston cylinder. The piston cylinder is connected to the intermediate cylinder to form two independent closed cavities at the upper and lower ends of the piston. The first one-way valve is arranged on the piston, and the second pressure sensor and the second one-way valve are arranged at the lower end of the piston cylinder.
[0014] Furthermore, the upper joint assembly also includes a high-pressure socket, a screw ring and an upper joint; the docking valve is fixed on the left side of the upper end of the upper joint, the first pressure sensor is fixed on the right side of the upper end of the upper joint, the high-pressure socket is fixed on the middle of the upper end of the upper joint, and the screw ring is fixed on the outside of the upper joint.
[0015] Furthermore, the limiting cylinder is fixedly connected to a bearing seat, and a thrust ball bearing and a needle bearing are installed between the trapezoidal lead screw and the bearing seat.
[0016] Furthermore, the upper joint assembly is internally connected to the power device via a wire passing tube, and the wire passing tube passes through the wires of the DC motor, the first limit switch and the second limit switch.
[0017] Furthermore, a cover plate is provided at the connection between the upper joint assembly and the two side walls of the power device to protect the wire passing tube.
[0018] In a second aspect, the present invention provides a leak detection method for a wellbore leak detection tool for an oil production well, comprising the following steps: The wellbore leak detection tool is connected to the lower end of the sealing tool. After the sealing tool is set in the well, the wellbore is divided into two independent spaces, the upper end and the lower end. The pressurizing device repeatedly pumps the well fluid extracted from the upper end of the wellbore to the lower end of the wellbore; As the well fluid at the lower end of the wellbore increases, the pressure at the lower end of the wellbore also increases. The first pressure sensor monitors the pressure at the upper end of the wellbore, and the second pressure sensor monitors the pressure at the lower end of the wellbore. Determine whether a well section is leaking by monitoring pressure changes.
[0019] Furthermore, the DC motor of the power device drives the screw device to convert the rotational motion into linear motion, thereby driving the pressurizing device connected to the screw device to move, and pumping the well fluid extracted from the upper end of the wellbore to the lower end of the wellbore.
[0020] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention provides a wellbore leak detection tool for oil production wells, which has a simple mechanical structure, a safe and reliable operation process, can intuitively obtain the detection results through the changes of the pressure sensor, and has low development and operation costs. Compared with the existing methods, the present invention is not limited by the size of the leakage, and can accurately detect both large and small leakage. At the same time, the detection process is not affected by factors such as fluid properties and flow conditions, and the results are more reliable. In addition, due to its simple structure and low cost, the technical requirements for operators are relatively low, and it is more convenient to promote and apply in actual production.
[0021] Specifically, the reciprocating motion of the piston is achieved by driving the screw device through a DC motor. The operation process is highly automated, reducing manual intervention and the labor intensity of operators. At the same time, the pressure sensor monitors the pressure changes in real time, and the detection results are intuitive, which facilitates operators to quickly determine whether there is a leak in the wellbore. The limit switch in the power system component controls the movement stroke of the screw to prevent the piston from moving beyond the limit position, ensuring the safe operation of the tool.
[0022] The present invention discloses a leak detection method for a wellbore leak detection tool for an oil well. The wellbore is connected to the lower end of the sealing tool through an upper joint assembly. After the sealing tool is sealed in the well, the wellbore is divided into two independent spaces at the upper end and the lower end. The power device and the screw device convert the rotary motion into a linear motion, drive the pressurizing device to move forward and backward, change the pressure at the upper and lower ends of the pressurizing device, and flow the well fluid into the lower wellbore of the sealing tool to increase the pressure. The pressure of the upper and lower wellbores is monitored in real time by a pressure sensor. If the pressure in the well increases to a certain value and remains unchanged within a certain period of time, it can be determined that the well section has no leakage. The present invention adopts a pressure test method, and determines the leakage point by pressurizing the closed space to be detected in the well and monitoring the pressure change. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 The figure is a schematic diagram of the overall structure of a wellbore leak detection tool for an oil well according to an embodiment of the present invention.
[0024] Figure 2 The present invention is a schematic structural diagram of an upper joint assembly of a wellbore leak detection tool for an oil well according to an embodiment of the present invention.
[0025] Figure 3 The present invention is a schematic structural diagram of a power system component of a wellbore leak detection tool for an oil well according to an embodiment of the present invention.
[0026] In the figure, 1, upper joint assembly; 1-1, first pressure sensor; 1-2, high-voltage socket; 1-3, screw ring; 1-4, upper joint; 1-5, docking valve; 2, power system assembly; 2-1, plug; 2-2, DC motor with reducer; 2-3, thrust ball bearing; 2-4, needle bearing; 2-5, limit cylinder; 2-6, first limit switch; 2-7, trapezoidal screw; 2-8, intermediate cylinder; 2-9, push-pull rod; 2-10, piston cylinder; 2-11, piston; 2-12, first one-way valve; 2-13, second pressure sensor; 2-14, anti-rotation key; 2-15, power housing; 2-16, bearing housing; 2-17, motor housing; 2-18, coupling; 2-19, slot; 2-20, second limit switch; 2-21, second one-way valve; 3. Rod body; 4. First hard tube; 5. Cover plate; 6. Wire passing tube; 7. Second hard tube. DETAILED DESCRIPTION
[0027] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.
[0028] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.
[0029] In order to detect the depth of the casing leakage point of the oil well, timely remedy and repair the casing, reduce the problems such as blowout or well collapse caused by leakage, and reduce the risk of endangering drilling equipment and posing a threat to the environment and personnel safety. The present invention provides a wellbore leakage detection tool for oil wells. Compared with the prior art, the present invention can reduce the cost of casing leakage detection, the tool has a simple mechanical structure, is safe and reliable, has a low failure rate, and has a low later maintenance cost, and can be widely used in the well logging market.
[0030] Example 1 See also Figures 1 to 3 The wellbore leak detection tool includes an upper joint assembly 1, a power system assembly 2, a rod body component 3 and a hard pipe 4; the upper joint assembly 1 includes a docking valve 1-5 and a first pressure sensor 1-1 is provided on the upper joint assembly 1, the lower end of the upper joint assembly 1 is connected to the upper end of the rod body component 3 by screws, and the upper joint assembly 1 is connected to the power system assembly 2; The power system component 2 includes a power device, a screw device and a pressurizing device; the power device, the screw device and the pressurizing device are connected in sequence and then integrally embedded in the rod body component 3 and fixedly connected by screws; the docking valve 1-5 is connected to one end of the first hard pipe 4 through the pipeline inside the upper joint component 1, and the other end of the first hard pipe 4 is connected to the pressurizing device, and the pressurizing device is provided with a second pressure sensor 2-13, and the second hard pipe 7 passes through the wire of the second pressure sensor 2-13; the upper joint component 1 is used to connect the mechanical interface at the lower end of the sealing tool to realize the mechanical connection function; the power device 2 provides power for the entire wellbore leak detection tool and drives the screw device, and the power device screw device cooperates to convert the rotational motion into linear motion to provide push-pull force for the pressurizing device; the pressurizing device is used to increase the pressure at the lower end of the wellbore; the rod body component 3 is used to carry the power system component 2 to ensure the structural stability of the wellbore leak detection tool in the wellbore.
[0031] Example 2 See also Figure 1 , Figure 3 , further describing the power system component 2, the power device includes a DC motor with a reducer 2-2 for providing power for the wellbore leak detection tool, and the output end is connected to the screw device; the input end of the DC motor 2-2 is fixed with a plug 2-1 by a screw, which is used to seal the power system component and lead out the wire. The power device provides power for the entire wellbore leak detection tool, and the screw device is driven to work through the operation of the DC motor 2-2.
[0032] The screw device includes a thrust ball bearing 2-3, a needle bearing 2-4, a limit cylinder 2-5, a first limit switch 2-6, a trapezoidal screw 2-7, an intermediate cylinder 2-8, a push-pull rod 2-9, a limit block 2-14 and a second limit switch 2-20; one end of the power housing 2-15 is connected to the plug 2-1, and the other end is connected to the pressurizing device, the upper end of the bearing housing 2-16 is connected to the motor housing 2-17, and the lower end is connected to the limit cylinder 2-5, the lower end of the limit cylinder 2-5 is connected to the intermediate cylinder 2-8, the trapezoidal screw 2-7 is arranged inside the limit cylinder 2-5 and the upper end of the trapezoidal screw 2-7 is connected through the coupling 2-1 8 is connected to the output end of the DC motor 2-2, the lower end of the trapezoidal lead screw 2-7 is connected to the upper end of the push-pull rod 2-9, and the lower end of the push-pull rod 2-9 is connected to the pressurizing device; the upper and lower side walls of the limit cylinder 2-5 are provided with a slot 2-19, the upper end of the slot 2-19 of the limit cylinder 2-5 is provided with a first limit switch 2-6, the lower end of the slot 2-19 of the limit cylinder 2-5 is provided with a second limit switch 2-20, and the slot 2-19 is provided with an anti-rotation key 2-14, and the limit cylinder 2-5 and the trapezoidal lead screw 2-7 make reciprocating motion in the slot 2-19 through the anti-rotation key 2-14 to provide a push-pull force for the pressurizing device; The pressurizing device includes a piston cylinder 2-10, a piston 2-11, a first one-way valve 2-12, a second pressure sensor 2-13 and a second one-way valve 2-21; The push-pull rod 2-9 extends to the inside of the intermediate cylinder 2-8 to connect to the piston 2-11. The piston 2-11 is slidably arranged inside the piston cylinder 2-10. The piston cylinder 2-10 and the intermediate cylinder 2-8 are connected by a threaded and sealing ring structure, forming two independent closed cavities at the upper and lower ends of the piston 2-11; the first one-way valve 2-12 is arranged on the piston 2-11, which is used to press the liquid at the upper end of the piston 2-11 into the lower end of the piston 2-11. The second pressure sensor 2-13 and the second one-way valve 2-21 are arranged at the lower end of the piston cylinder 2-10. The second one-way valve 2-21 is used to press the liquid at the lower end of the piston 2-11 into the outside of the wellbore leakage detection tool; the push-pull rod 2-9 can drive the piston 2-11 to reciprocate, suck the well fluid at the upper end of the sealing tool into the upper end cavity of the piston 2-11, and enter the lower end cavity of the piston 2-11 through the first one-way valve 2-12 installed on the piston 2-11, and then push the well fluid into the closed space at the lower end of the wellbore. As the amount of well fluid in the closed wellbore space outside the wellbore leak detection tool increases, the pressure inside the wellbore increases. The pressure sensor 2-13 installed at the lower end of the piston cylinder 2-10 monitors the pressure change of the well fluid in the wellbore and transmits the signal to the ground. If the pressure in the well increases to a certain value and remains unchanged within a certain period of time, it can be determined that there is no leakage in the well section.
[0033] It should be noted that the increase in well pressure to a certain value and for a certain time here refers to the pressure required by the user; for example, if it needs to be increased to 20MPa, then when the well pressure increases by 20MPa and the pressure remains unchanged within 30 minutes, it can be determined that there is no leakage in the well section. If the pressure changes, it can be determined that there is leakage in the well section.
[0034] In some preferred embodiments of the present invention, the upper joint assembly 1 also includes a high-pressure socket 1-2, a screw ring 1-3 and an upper joint 1-4; the docking valve 1-5 is fixed on the left side of the upper end of the upper joint 1-4, and the first pressure sensor 1-1 is fixed on the right side of the upper end of the upper joint 1-4, which can monitor the pressure of the well fluid at the upper end of the sealing tool in real time; the high-pressure socket 1-2 is fixed in the middle of the upper end of the upper joint 1-4, and is used to electrically connect the lower end of the sealing tool. The high-pressure plug-in 1-2 is used here to isolate the sealing tool and the wellbore leak detection tool, so that the grouting of one of them will not cause the grouting of the other; the screw ring 1-3 is fixed on the outside of the upper joint 1-4, connecting the mechanical interface at the lower end of the sealing tool; the docking valve 1-5 is installed at the upper end of the upper joint 1-4, and its function is to introduce mud from the reserved hole of the sealing tool into the wellbore leak detection tool when the sealing tool is connected to the wellbore leak detection tool.
[0035] In some preferred embodiments of the present invention, the limit cylinder 2-5 is fixedly connected to the bearing seat 2-16, and a thrust ball bearing 2-3 and a needle roller bearing 2-4 are also arranged between the trapezoidal screw 2-7 and the bearing housing 2-16. The thrust ball bearing 2-3 is mainly used to bear axial loads, making the operation of the tool more stable, safe and reliable. The needle roller bearing 2-4 mainly bears radial loads, effectively reducing the friction generated during the rotation of the trapezoidal screw 2-7, extending the life of the tool and ensuring its stable operation.
[0036] In some preferred embodiments of the present invention, the upper joint assembly 1 is internally connected to the power device via a wire tube 6, and the wire tube 6 passes through the wires of the DC motor 2-2, the first limit switch 2-6 and the second limit switch 2-20.
[0037] In some preferred embodiments of the present invention, a cover plate 5 is provided at the connection between the upper joint assembly 1 and the two side walls of the power device, and the cover plate 5 is used to protect the high-pressure hard pipe 4 and the wire pipe 6 exposed to the well fluid.
[0038] The present invention provides a leakage detection method for a wellbore leakage detection tool for an oil production well, which is implemented based on the wellbore leakage detection tool described above and comprises the following steps: The wellbore leak detection tool is connected to the lower end of the sealing tool. After the sealing tool is set in the well, the wellbore is divided into two independent spaces, the upper end and the lower end. The pressurizing device repeatedly pumps the well fluid extracted from the upper end of the wellbore to the lower end of the wellbore; As the wellbore fluid increases at the lower end of the wellbore, the pressure at the lower end of the wellbore also increases. The first pressure sensor 1-1 monitors the pressure at the upper end of the wellbore, and the second pressure sensor 2-13 monitors the pressure at the lower end of the wellbore; Determine whether a well section is leaking by monitoring pressure changes.
[0039] Specifically, when the DC motor 2-2 rotates forward, the push-pull rod 2-9 drives the pressure piston 2-11 to move forward, forming a low-pressure chamber at the upper end of the piston 2-11 and a high-pressure chamber at the lower end of the piston 2-11. The well fluid at the upper end of the sealing tool fills the low-pressure chamber as the piston 2-11 moves forward. When the piston 2-11 moves to the extreme position and touches the first limit switch 2-6, the motor reverses; After the motor reverses, the piston 2-11 moves backward, squeezing the low-pressure chamber fluid. When the internal pressure reaches the opening pressure of the safety valve, the low-pressure chamber fluid flows into the high-pressure chamber through the first one-way valve 2-12. When the piston 2-11 moves to the limit position and touches the second limit switch 2-20, the motor reverses again; At this time, the motor rotates forward again, the piston 2-11 moves forward, the well fluid at the upper end of the packer flows into the low-pressure chamber again, and the well fluid in the high-pressure chamber is squeezed. When the internal pressure reaches the opening pressure of the safety valve, the well fluid in the high-pressure chamber flows into the lower wellbore of the sealing tool through the second one-way valve 2-21, thereby increasing the pressure.
[0040] During the whole process, the first pressure sensor 1-1 on the upper joint assembly 1 monitors the pressure of the well fluid at the upper end of the sealing tool in real time, and the second pressure sensor 2-13 on the pressurizing device monitors the pressure change of the well fluid in the wellbore at the lower end of the sealing tool and transmits the signal to the ground. If the pressure in the well increases to a certain value and remains unchanged for a certain period of time, it can be determined that there is no leakage in the well section.
[0041] The wellbore leak detection tool for oil production wells of the present invention has the advantages of simple structure, convenient operation, accurate detection, safety and reliability, etc., can effectively meet the wellbore leak detection needs of oil production wells, and has broad market application prospects.
[0042] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.
[0043] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A wellbore leak detection tool for oil wells, characterized in that: The invention comprises an upper joint assembly (1), a power system assembly (2), a rod body component (3) and a hard pipe (4); the upper joint assembly (1) comprises a docking valve (1-5) and a first pressure sensor (1-1) is arranged on the upper joint assembly (1); the lower end of the upper joint assembly (1) is connected to the rod body component (3) and the upper joint assembly (1) is connected to the power system assembly (2); The power system component (2) comprises a power device, a screw device and a pressurizing device; the power device, the screw device and the pressurizing device are connected in sequence and then integrally embedded in the rod body component (3) and fixedly connected; the docking valve (1-5) is connected to one end of a first hard pipe (4) via a pipeline inside the upper joint component (1), and the other end of the first hard pipe (4) is connected to the pressurizing device; a second pressure sensor (2-13) is provided on the pressurizing device, and a wire of the second pressure sensor (2-13) is passed through the second hard pipe (7).
2. A wellbore leak detection tool for oil wells according to claim 1, characterized in that: The power device comprises a DC motor with a reducer (2-2) and a motor housing (2-17); the output end of the DC motor (2-2) is connected to the screw device via a coupling (2-18); and a plug (2-1) is installed at the input end of the DC motor (2-2).
3. A wellbore leak detection tool for oil wells according to claim 2, characterized in that: The lead screw device comprises a limit cylinder (2-5), a first limit switch (2-6), a trapezoidal lead screw (2-7), an intermediate cylinder (2-8), a push-pull rod (2-9), a limit block (2-14) and a second limit switch (2-20); One end of the power housing (2-15) is connected to the plug (2-1), and the other end is connected to the pressurizing device; the upper end of the bearing housing (2-16) is connected to the motor housing (2-17), and the lower end is connected to the limit cylinder (2-5); the lower end of the limit cylinder (2-5) is connected to the intermediate cylinder (2-8); the trapezoidal lead screw (2-7) is arranged inside the limit cylinder (2-5), and the upper end of the trapezoidal lead screw (2-7) is connected to the output end of the DC motor (2-2) via a coupling (2-18); the lower end of the trapezoidal lead screw (2-7) is connected to the upper end of the push-pull rod (2-9), and the lower end of the push-pull rod (2-9) is connected to the pressurizing device; The upper and lower side walls of the limit cylinder (2-5) are both provided with a slot (2-19); the upper end of the slot (2-19) of the limit cylinder (2-5) is provided with a first limit switch (2-6); the lower end of the slot (2-19) of the limit cylinder (2-5) is provided with a second limit switch (2-20); an anti-rotation key (2-14) is provided on the slot (2-19); the limit cylinder (2-5) and the trapezoidal lead screw (2-7) perform reciprocating motion in the slot (2-19) via the anti-rotation key (2-14), thereby providing a push-pull force for the pressurizing device.
4. A wellbore leak detection tool for oil wells according to claim 3, characterized in that: The pressurizing device comprises a piston cylinder (2-10), a piston (2-11), a first one-way valve (2-12), a second pressure sensor (2-13) and a second one-way valve (2-21); The push-pull rod (2-9) extends to the interior of the intermediate cylinder (2-8) and is connected to the piston (2-11). The piston (2-11) is slidably arranged inside the piston cylinder (2-10). The piston cylinder (2-10) is connected to the intermediate cylinder (2-8), and the upper and lower ends of the piston (2-11) form two mutually independent closed cavities. The first one-way valve (2-12) is arranged on the piston (2-11), and the second pressure sensor (2-13) and the second one-way valve (2-21) are arranged at the lower end of the piston cylinder (2-10).
5. A wellbore leak detection tool for oil wells according to claim 1, characterized in that: The upper joint assembly (1) further comprises a high-pressure socket (1-2), a screw ring (1-3) and an upper joint (1-4); the docking valve (1-5) is fixed to the left side of the upper end of the upper joint (1-4), the first pressure sensor (1-1) is fixed to the right side of the upper end of the upper joint (1-4), the high-pressure socket (1-2) is fixed to the middle of the upper end of the upper joint (1-4), and the screw ring (1-3) is fixed to the outer side of the upper joint (1-4).
6. A wellbore leak detection tool for oil wells according to claim 3, characterized in that: The limiting cylinder (2-5) is fixedly connected to a bearing seat (2-16), and a thrust ball bearing (2-3) and a needle roller bearing (2-4) are installed between the trapezoidal lead screw (2-7) and the bearing seat (2-16).
7. A wellbore leak detection tool for oil wells according to claim 3, characterized in that: The upper joint assembly (1) is internally connected to the power device via a wire tube (6), and the wire tube (6) passes through the wires of the DC motor (2-2), the first limit switch (2-6) and the second limit switch (2-20).
8. A wellbore leak detection tool for oil wells according to claim 7, characterized in that: A cover plate (5) is provided at the connection between the upper joint assembly (1) and the two side walls of the power device to protect the wire passing tube (6).
9. A leak detection method for a wellbore leak detection tool for an oil well according to any one of claims 1 to 8, characterized in that: The following steps are involved: The wellbore leak detection tool is connected to the lower end of the sealing tool. After the sealing tool is set in the well, the wellbore is divided into two independent spaces, the upper end and the lower end. The pressurizing device repeatedly pumps the well fluid extracted from the upper end of the wellbore to the lower end of the wellbore; As the well fluid at the lower end of the wellbore increases, the pressure at the lower end of the wellbore also increases, the first pressure sensor (1-1) monitors the pressure at the upper end of the wellbore, and the second pressure sensor (2-13) monitors the pressure at the lower end of the wellbore; Determine whether a well section is leaking by monitoring pressure changes.
10. A leak detection method for a wellbore leak detection tool for an oil well according to claim 9, characterized in that: The DC motor (2-2) of the power device drives the screw device to convert the rotary motion into linear motion, thereby driving the pressurizing device connected to the screw device to move, and pumping the well fluid extracted from the upper end of the wellbore to the lower end of the wellbore.