Microseismic signal acquisition device for oil well

Abstract

The utility model discloses a microseismic signal acquisition device for an oil well, which relates to the technical field of seismic signal acquisition devices and comprises a ground control unit, an underground acquisition unit and an air pressure control unit. Wherein the underground acquisition unit comprises a cylindrical frame, a fixed rod extending along one axial end of the frame, a plurality of micro-seismic sensors movably accommodated in the frame and a flexible expansion piece; the air pressure control unit is used for controlling the flexible expansion piece to expand or contract, and the plurality of microseismic sensors protrude out of the outer surface of the frame when the flexible expansion piece is in an expansion state; and the ground control unit is electrically connected with the microseismic sensor and is used for receiving monitoring data. According to the utility model, the limitation of the traditional micro-seismic sensor in the application of an oil well is solved, the balance of high quality of signal acquisition, recoverability of equipment and cost effectiveness is realized, and the sensor can be conveniently disassembled and repeatedly used while good signal coupling is maintained.

Description

Technical Field

[0001] The utility model relates to the technical field of seismic signal acquisition devices, in particular to a microseismic signal acquisition device for oil wells. Background Art

[0002] In geological science and engineering practice, the use of seismic waves to explore stratum structure, analyze deep rock characteristics, and monitor rock ground pressure activity has become an indispensable and efficient technical approach. The core of this method lies in the accurate capture and analysis of seismic waves to obtain key information about underground geological structure, rock properties, and even potential resource distribution. Seismic waves, as carriers of the code of the deep structure of the earth, their characteristics and propagation modes can reflect the physical properties of underground media, such as density, elastic modulus, and stress state.

[0003] To achieve this goal, seismic sensors play a vital role. They are designed to sense and record the subtle fluctuations of seismic waves, thereby providing detailed data about the underground environment. Microseismic sensors, with their high sensitivity and fast response speed, have shown broad application prospects in many fields such as geological exploration, mineral resource exploration, oil shale gas mining, mine ground pressure activity monitoring, and geotechnical engineering stability assessment.

[0004] However, the coupling mode and quality between the sensor and the rock medium are crucial to ensure the accuracy and integrity of the seismic wave signal. Improper coupling may cause signal attenuation or distortion, affecting the reliability and interpretation accuracy of the data. In practice, the strategies for drilling microseismic sensors are mainly divided into two categories:

[0005] Full-hole grouting installation: This installation method involves permanently sealing the sensor in the borehole and achieving close contact with the surrounding rock through grouting. Although this method provides good coupling effect and long-term stability, a significant disadvantage is that the sensor cannot be recovered once deployed, which means that new sensors need to be replaced after each monitoring mission, which not only increases costs but also brings about resource waste.

[0006] Removable mounting method: In contrast, the removable mounting solution allows for a stable coupling between the sensor and the rock surface, while allowing for easy removal and recovery of the sensor after the monitoring mission is completed. This flexibility not only promotes the reuse of sensors, reduces overall costs, but also reduces environmental impact and improves resource efficiency. In addition, the removable mounting method facilitates the maintenance, upgrade, and replacement of sensors, helping to ensure continued optimization and performance improvement of the monitoring system.

[0007] In view of this, it is urgent to develop a microseismic sensor that can ensure signal quality while having economic and environmental advantages. Utility Model Content

[0008] Based on this, the purpose of the utility model is to provide a microseismic signal acquisition device for oil wells to solve the existing technical problems.

[0009] To achieve the above-mentioned purpose, the utility model provides the following technical solution: a microseismic signal acquisition device for oil wells, comprising a ground control unit, a downhole acquisition unit and a gas pressure control unit, wherein:

[0010] The downhole acquisition unit comprises a cylindrical frame, a fixing rod extending along one axial end of the frame, a plurality of microseismic sensors movably accommodated in the frame, and a flexible expansion member;

[0011] The air pressure control unit is used to control the flexible expansion member to expand or contract it, and when the flexible expansion member is in an expanded state, a plurality of microseismic sensors protrude from the outer surface of the frame;

[0012] The ground control unit is electrically connected to the microseismic sensor for receiving monitoring data.

[0013] By adopting the above technical solution, a detachable installation method is adopted, combined with a flexible expansion piece controlled by air pressure, it is possible to ensure convenient disassembly and reuse of the sensor while maintaining good signal coupling.

[0014] The utility model is further configured such that a hollow accommodating cavity is formed on the inner side of the frame and a plurality of movable windows communicating with the accommodating cavity are opened along the axial direction of the outer wall of the air chamber, the upper and lower ends of the microseismic sensor are fixed to the inner side of the movable window by a pair of stretchable and deformable flexible ropes, and the flexible expansion member is arranged on the inner side of a plurality of microseismic sensors.

[0015] By adopting the above technical solution, a stretchable and deformable flexible rope is set in the frame to fix the microseismic sensor, and the expansion effect of the flexible expansion piece is used to make the sensor fit closely to the well wall, which significantly improves the coupling effect of signal acquisition and the reliability of signal transmission.

[0016] The utility model is further configured that the fixing rod is arranged to penetrate along the middle part of the frame, and the flexible expansion member is arranged around the fixing rod in the accommodating cavity located in the frame.

[0017] By adopting the above technical solution, the fixed rod is set through the middle of the frame, which not only provides a stable support for the whole device, but also acts as a central axis to ensure the vertical stability and directional consistency of the device in the underground environment. The flexible expansion member is arranged around the fixed rod in the accommodating cavity in the frame, which makes full use of the space, so that the expansion member can apply force evenly when inflated, pushing the microseismic sensor close to the well wall, effectively improving the coupling effect between the sensor and the rock medium, thereby enhancing the acquisition quality of seismic signals and the accuracy of data.

[0018] The utility model is further configured such that the flexible rope is a hollow nylon braided rope, and a cable electrically connected to the microseismic sensor is provided inside the nylon braided rope.

[0019] By adopting the above technical solution, the flexible rope is designed as a hollow nylon braided rope, and a cable electrically connected to the microseismic sensor is arranged inside it, which can ensure the stable transmission of signals from the sensor to the ground control unit. The hollow structure of the nylon braided rope not only provides a protective channel for the cable, preventing the cable from being damaged in a complex underground environment, but also the high strength and corrosion resistance of the nylon material enable the flexible rope to maintain good mechanical properties and electrical insulation under harsh conditions, thereby extending the service life of the device.

[0020] The utility model is further configured such that a hollow wiring cavity is formed inside the fixing rod, and a plurality of cables are led out along the wiring cavity to the outside of the end of the fixing rod.

[0021] By adopting the above technical solution, the hollow wiring cavity formed inside the fixed rod provides a safe channel for the cable, so that the cable can be led out from the microseismic sensor in an orderly manner, along the wiring cavity directly to the outside of the end of the fixed rod, and connected to the ground control unit or other external equipment. It not only simplifies the layout of the cable and avoids the damage that the cable may suffer in the complex environment underground, such as wear, extrusion or chemical corrosion, but also greatly reduces the risk of signal interference caused by cable confusion, ensuring the stability and accuracy of signal transmission.

[0022] The utility model is further configured that an air delivery pipe is provided at the upper end of the flexible expansion member, and the air delivery pipe penetrates into the wiring cavity along the inner side of the frame and passes out along the end of the fixing rod and then is connected to the air pressure control unit.

[0023] By adopting the above technical solution, the gas pipe set at the upper end of the flexible expansion member can not only pass through the wiring cavity along the inner side of the frame, but also smoothly pass through the end of the fixed rod and finally connect to the air pressure control unit. This ensures that the air pressure control unit can accurately deliver gas to the flexible expansion member to achieve regulation of its expansion or contraction state. The path planning of the gas pipe is cleverly integrated into the structure of the device, which not only reduces the additional pipeline layout and simplifies the appearance of the device, but also effectively prevents the gas pipe from being damaged in the complex environment underground, ensuring the stability and reliability of air pressure control.

[0024] The utility model is further configured that the air pressure control unit includes a control module and a micro air pump, the air supply pipe is connected to the output end of the micro air pump, and an electromagnetic air valve is provided on the air supply pipe.

[0025] By adopting the above technical solution, the air pressure control unit is composed of a control module and a micro air pump, wherein the output end of the micro air pump is directly connected to the gas pipe, responsible for providing the required gas pressure to the flexible expansion member; and the setting of the solenoid gas valve provides the gas circuit with intelligent control capabilities, which can be quickly opened or closed under the command of the control module, thereby accurately adjusting the gas flow in the gas pipe and realizing fine control of the expansion degree of the flexible expansion member.

[0026] The utility model is further configured that two movable windows are provided on the same horizontal plane of the frame and are distributed symmetrically with respect to the radial direction of the frame.

[0027] By adopting the above technical solution, two movable windows with radial symmetry about the frame are set on the same horizontal plane of the frame to ensure the symmetrical distribution of microseismic sensors on the well wall, so that more comprehensive and balanced seismic wave information can be captured during the signal acquisition process. Symmetrically distributed sensors can not only reduce signal deviations caused by irregularities in the well wall, but also verify each other to improve the accuracy and reliability of the data. In addition, this design also helps to balance the positioning of the device underground, reduce the deviation or tilt that may be caused by unilateral gravity, ensure the stability of the device and the safety of operation, and provide more accurate and reliable microseismic signal acquisition capabilities for oil well monitoring.

[0028] The utility model is further configured that the movable windows are provided with two groups along the radial direction of the frame.

[0029] By adopting the above technical solution, two groups of movable windows are set in the radial direction of the frame, and microseismic sensors are placed in each group of windows, so that the device can collect seismic signals in multiple directions at the same time, effectively expanding the coverage of signal collection, improving the ability to perceive changes in underground structures and the accuracy of earthquake event positioning. The collaborative work of multiple groups of sensors can not only capture seismic wave information in a wider area, but also reduce the possible errors of a single sensor through cross-validation, ensuring the integrity and reliability of the data.

[0030] The utility model is further configured that the flexible expansion member is an air bag.

[0031] By adopting the above technical solution, the airbag, as a lightweight, flexible and compressible material, can be adaptively expanded according to the actual situation of the well wall, ensuring good contact between the sensor and the well wall, thereby improving the coupling effect of signal acquisition.

[0032] In summary, the utility model mainly has the following beneficial effects:

[0033] The utility model proposes to solve the limitations of traditional microseismic sensors in oil well applications through an integrated frame structure, achieving a balance between high quality signal acquisition, equipment recyclability and cost-effectiveness. Specifically, the device adopts a detachable installation method, combined with a flexible expansion piece controlled by air pressure, which can ensure convenient disassembly and reuse of the sensor while maintaining good signal coupling.

[0034] In addition, the expansion state of the flexible expansion piece under air pressure control enables the microseismic sensor to fit stably on the well wall, effectively avoiding the problem of signal attenuation or distortion and ensuring the accuracy and integrity of the seismic signal.

[0035] In addition, the detachable design allows the microseismic sensors to be easily recycled and reused after completing the monitoring task, which significantly reduces costs and reduces resource waste, reflecting the dual considerations of economic benefits and environmental protection.

[0036] In addition, design details such as flexible ropes, cables and wiring cavities in the device ensure the reliability of signal transmission, while also facilitating maintenance, upgrading and replacement of equipment, improving the flexibility and adaptability of the system.

[0037] In addition, the integrated design of the air pressure control unit, including the control module and the micro air pump, combined with the electromagnetic air valve, realizes precise control of the flexible expansion piece and enhances the automation level of the entire system.

[0038] In addition, through reasonable layout, such as the symmetrical distribution and grouping design of the active windows, and the choice of airbags as flexible expansion members, the compact structure of the device is ensured, while the uniformity and coverage of signal acquisition are improved.

[0039] To sum up, the microseismic signal acquisition device for oil wells of the utility model not only realizes accurate and efficient signal acquisition at the technical level, but also shows significant advantages in economy and environmental protection, providing a better solution for the fields of geological exploration, mineral resource exploration, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0041] Figure 2 It is a partial cross-sectional structural schematic diagram of the utility model;

[0042] Figure 3 for Figure 2 A schematic diagram of the local enlarged structure of the middle A area;

[0043] Figure 4 This is a schematic diagram of the use state of the utility model;

[0044] Figure 5 This is a connection principle block diagram of the utility model.

[0045] In the figure: 10, ground control unit; 20, air pressure control unit; 30, downhole acquisition unit; 31, frame; 311, accommodating chamber; 312, movable window; 32, fixing rod; 321, wiring chamber; 33, microseismic sensor; 34, flexible expansion member; 341, gas pipe; 342, electromagnetic gas valve; 40, flexible rope; 41, cable; 42, braided sleeve. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. The embodiments described below with reference to the drawings are exemplary and are only used to explain the utility model, and cannot be understood as limiting the utility model.

[0047] The following describes an embodiment of the utility model based on its overall structure.

[0048] A microseismic signal acquisition device for oil wells, such as Figure 1-5 As shown, it includes a surface control unit 10, a downhole acquisition unit 30 and a gas pressure control unit 20, wherein:

[0049] The downhole acquisition unit 30 includes a cylindrical frame 31, a fixing rod 32 extending along one axial end of the frame 31, a plurality of microseismic sensors 33 movably accommodated in the frame 31, and a flexible expansion member 34. In this embodiment, the frame 31 is in the shape of an elongated column sleeve as a whole, and the fixing rod 32 is in the shape of an elongated rod;

[0050] The air pressure control unit 20 is used to control the flexible expansion member 34 to expand or contract it, and when the flexible expansion member 34 is in an expanded state, a plurality of microseismic sensors 33 protrude from the outer surface of the frame 31;

[0051] The ground control unit 10 is electrically connected to the microseismic sensor 33 for receiving monitoring data.

[0052] Preferably, a hollow accommodating chamber 311 is formed on the inner side of the frame 31, and a plurality of movable windows 312 communicating with the accommodating chamber 311 are provided on the outer side wall along its axial direction. The upper and lower ends of the microseismic sensor 33 are fixed to the inner side of the movable window 312 by a pair of stretchable and deformable flexible ropes 40, and the flexible expansion member 34 is arranged on the inner side of the plurality of microseismic sensors 33. The microseismic sensor 33 is fixed by arranging a stretchable and deformable flexible rope 40 in the frame 31, and the expansion effect of the flexible expansion member 34 is utilized to make the sensor fit closely to the well wall, thereby significantly improving the coupling effect of signal acquisition and the reliability of signal transmission.

[0053] Particularly, in this embodiment, the movable window 312 is an arc-shaped window opened along the arc-shaped surface of the outer surface of the frame 31 .

[0054] Preferably, the fixed rod 32 is arranged along the middle of the frame 31, and the flexible expansion member 34 is arranged around the fixed rod 32 in the accommodating cavity 311 in the frame 31. The fixed rod 32 is arranged along the middle of the frame 31, which not only provides a stable support for the entire device, but also acts as a central axis to ensure the vertical stability and directional consistency of the device in the underground environment. The flexible expansion member 34 is arranged around the fixed rod 32 in the accommodating cavity 311 in the frame 31, which fully utilizes the space, so that the expansion member can apply force evenly when inflated, pushing the microseismic sensor 33 close to the well wall, effectively improving the coupling effect between the sensor and the rock medium, thereby enhancing the acquisition quality of seismic signals and the accuracy of data.

[0055] Preferably, the flexible rope 40 is a hollow nylon braided rope, and a cable 41 electrically connected to the microseismic sensor 33 is arranged inside the nylon braided rope. The flexible rope 40 is designed as a hollow nylon braided rope, and a cable 41 electrically connected to the microseismic sensor 33 is arranged inside the flexible rope 40, so as to ensure stable transmission of signals from the sensor to the ground control unit 10. The hollow structure of the nylon braided rope not only provides a protection channel for the cable 41, and prevents the cable 41 from being damaged in a complex underground environment, but also the high strength and corrosion resistance of the nylon material enable the flexible rope 40 to maintain good mechanical properties and electrical insulation under harsh conditions, thereby extending the service life of the device.

[0056] Preferably, a hollow wiring cavity 321 is formed inside the fixed rod 32, and a plurality of cables 41 are led out along the wiring cavity 321 to the outside of the end of the fixed rod 32. In particular, in this embodiment, a plurality of cables 41 are combined into one strand in the wiring cavity 321 and a braided sleeve 42 is provided for protection. The hollow wiring cavity 321 formed inside the fixed rod 32 provides a safe passage for the cables 41, so that the cables 41 can be led out from the microseismic sensor 33 in an orderly manner, and directly reach the outside of the end of the fixed rod 32 along the wiring cavity 321, and connected to the ground control unit 10 or other external devices. This not only simplifies the arrangement of the cables 41 and avoids possible damage to the cables 41 in the complex underground environment, such as wear, extrusion or chemical corrosion, but also greatly reduces the risk of signal interference caused by the chaos of the cables 41, ensuring the stability and accuracy of signal transmission.

[0057] Preferably, an air pipe 341 is provided at the upper end of the flexible expansion member 34. The air pipe 341 penetrates into the wiring cavity 321 along the inner side of the frame 31 and passes out along the end of the fixed rod 32 to be connected to the air pressure control unit 20. The air pipe 341 provided at the upper end of the flexible expansion member 34 can not only penetrate into the wiring cavity 321 along the inner side of the frame 31, but also pass smoothly through the end of the fixed rod 32, and finally be connected to the air pressure control unit 20. This ensures that the air pressure control unit 20 can accurately deliver gas to the flexible expansion member 34 to achieve the regulation of its expansion or contraction state. The path planning of the air pipe 341 is cleverly integrated into the structure of the device, which not only reduces the additional pipeline layout and simplifies the appearance of the device, but also effectively prevents the air pipe 341 from being damaged in the complex environment underground, thereby ensuring the stability and reliability of air pressure control.

[0058] Preferably, the air pressure control unit 20 includes a control module and a micro air pump (not shown in the figure), the air supply pipe 341 is connected to the output end of the micro air pump, and the air supply pipe 341 is provided with an electromagnetic valve 342. The air pressure control unit 20 consists of a control module and a micro air pump, wherein the output end of the micro air pump is directly connected to the air supply pipe 341, and is responsible for providing the required gas pressure to the flexible expansion member 34; and the setting of the electromagnetic valve 342 provides the air circuit with intelligent control capability, and can be quickly opened or closed under the command of the control module, thereby accurately adjusting the gas flow in the air supply pipe 341, and realizing fine control of the expansion degree of the flexible expansion member 34.

[0059] Preferably, two movable windows 312 are provided on the same horizontal plane of the frame 31 and are symmetrically distributed radially about the frame 31. Two movable windows 312 are provided on the same horizontal plane of the frame 31 and are symmetrically distributed radially about the frame 31, ensuring the symmetrical distribution of the microseismic sensors 33 on the well wall, so that more comprehensive and balanced seismic wave information can be captured during the signal acquisition process. Symmetrically distributed sensors can not only reduce signal deviations caused by irregularities in the well wall, but can also verify each other to improve the accuracy and reliability of the data. In addition, this design also helps to balance the positioning of the device underground, reduces the possible deviation or tilt caused by unilateral gravity, ensures the stability of the device and the safety of operation, and provides a more accurate and reliable microseismic signal acquisition capability for oil well monitoring.

[0060] Preferably, two groups of active windows 312 are provided along the radial direction of the frame 31, and two groups of active windows 312 are provided along the radial direction of the frame 31, and microseismic sensors 33 are placed in each group of windows, so that the device can collect seismic signals in multiple directions at the same time, effectively expanding the coverage of signal collection, improving the perception of underground structural changes and the accuracy of seismic event positioning. The collaborative work of multiple groups of sensors can not only capture seismic wave information in a wider area, but also reduce the possible errors of a single sensor through cross-validation, ensuring the integrity and reliability of the data.

[0061] Preferably, the flexible expansion member 34 is an airbag. As a light, flexible and compressible material, the airbag can be adaptively expanded according to the actual situation of the well wall to ensure good contact between the sensor and the well wall, thereby improving the coupling effect of signal acquisition.

[0062] In summary, the working process and main beneficial effects of the utility model are as follows:

[0063] Figure 4This is a schematic diagram of the use status of the utility model. First, the microseismic sensor 33 is fixed in the movable window 312 of the frame 31 through a stretchable flexible rope 40, and the airbag surrounds the fixed rod 32 and waits for the inflation command. Then, the device is slowly sent into the test hole to be tested in the well. After reaching the specified depth, the air pressure control unit 20 is started, and the micro air pump accurately controls the airflow to gradually expand the airbag, placing the sensor firmly on the well wall, forming an excellent coupling state, and ensuring the accurate capture of seismic signals. As the sensor starts to work, the weak seismic waves are converted into electrical signals, which pass through the wiring cavity 321 through the cable 41 embedded in the hollow nylon braided rope and finally reach the ground control unit 10. When the monitoring task is completed, the air pressure control unit 20 reverses the operation, the airbag shrinks, the device returns to its original state, and is easily recovered, entering a cycle of maintenance and redeployment.

[0064] The utility model proposes to solve the limitations of traditional microseismic sensors 33 in oil well applications through an integrated frame 31 structure, achieving a balance between high quality signal acquisition, recyclability of equipment and cost-effectiveness. Specifically, the device adopts a detachable installation method, combined with a flexible expansion member 34 controlled by air pressure, which can ensure convenient disassembly and reuse of the sensor while maintaining good signal coupling.

[0065] In addition, the expansion state of the flexible expansion member 34 under air pressure control enables the microseismic sensor 33 to be stably attached to the well wall, effectively avoiding the problem of signal attenuation or distortion, and ensuring the accuracy and integrity of the seismic signal.

[0066] In addition, the detachable design allows the microseismic sensor 33 to be easily recycled and reused after completing the monitoring task, which significantly reduces costs and reduces resource waste, reflecting the dual considerations of economic benefits and environmental protection.

[0067] In addition, design details such as the flexible rope 40, cable 41 and wiring cavity 321 in the device ensure the reliability of signal transmission, while also facilitating maintenance, upgrading and replacement of the equipment, thereby improving the flexibility and adaptability of the system.

[0068] In addition, the integrated design of the air pressure control unit 20, including the control module and the micro air pump, combined with the electromagnetic air valve 342, realizes the precise control of the flexible expansion member 34, and enhances the automation level of the entire system.

[0069] In addition, through reasonable layout, such as the symmetrical distribution and grouping design of the active windows 312, and the selection of the airbag as the flexible expansion member 34, the compact structure of the device is ensured, while the uniformity and coverage of signal acquisition are improved.

[0070] In summary, the microseismic signal acquisition device for oil wells of the utility model not only realizes accurate and efficient signal acquisition at the technical level, but also shows significant advantages in economy and environmental protection, providing a better solution for the fields of geological exploration, mineral resource exploration, etc.

[0071] Although an embodiment of the utility model has been shown and described, this specific embodiment is merely an explanation of the utility model and is not a limitation of the utility model. The specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. After reading this specification, those skilled in the art may make modifications, substitutions and variations to the embodiments without creative contributions as needed without departing from the principles and purpose of the utility model. However, as long as they are within the scope of the claims of the utility model, they are protected by patent law.

Claims

1. A microseismic signal acquisition device for oil wells, characterized in that: It comprises a surface control unit (10), a downhole acquisition unit (30) and a gas pressure control unit (20), wherein: The downhole acquisition unit (30) comprises a columnar frame (31), a fixing rod (32) extending along one axial end of the frame (31), a plurality of microseismic sensors (33) movably accommodated in the frame (31), and a flexible expansion member (34); The air pressure control unit (20) is used to control the flexible expansion member (34) to expand or contract the flexible expansion member (34), and when the flexible expansion member (34) is in an expanded state, a plurality of microseismic sensors (33) protrude from the outer surface of the frame (31); The ground control unit (10) is electrically connected to the microseismic sensor (33) and is used to receive monitoring data.

2. The microseismic signal acquisition device for oil wells according to claim 1, characterized in that: A hollow accommodating chamber (311) is formed on the inner side of the frame (31), and a plurality of movable windows (312) which are in communication with the accommodating chamber (311) are formed on the outer side wall along its axial direction. The upper and lower ends of the microseismic sensors (33) are fixed to the inner side of the movable windows (312) via a pair of stretchable and deformable flexible ropes (40), and the flexible expansion member (34) is arranged on the inner side of the plurality of microseismic sensors (33).

3. The microseismic signal acquisition device for oil wells according to claim 2, characterized in that: The fixing rod (32) is arranged to penetrate along the middle of the frame (31), and the flexible expansion member (34) is arranged around the fixing rod (32) in a receiving cavity (311) located in the frame (31).

4. The microseismic signal acquisition device for oil wells according to claim 2, characterized in that: The flexible rope (40) is a hollow nylon braided rope, and a cable (41) electrically connected to the microseismic sensor (33) is provided inside the nylon braided rope.

5. The microseismic signal acquisition device for oil wells according to claim 4, characterized in that: A hollow wiring cavity (321) is formed inside the fixing rod (32), and a plurality of cables (41) are led out along the wiring cavity (321) to the outside of the end of the fixing rod (32).

6. The microseismic signal acquisition device for oil wells according to claim 5, characterized in that: An air delivery pipe (341) is provided at the upper end of the flexible expansion member (34). The air delivery pipe (341) penetrates into the wiring cavity (321) along the inner side of the frame (31) and passes out along the end of the fixing rod (32) to be connected to the air pressure control unit (20).

7. The microseismic signal acquisition device for oil wells according to claim 6, characterized in that: The air pressure control unit (20) comprises a control module and a micro air pump, the air delivery pipe (341) is connected to the output end of the micro air pump, and an electromagnetic air valve (342) is provided on the air delivery pipe (341).

8. The microseismic signal acquisition device for oil wells according to claim 2, characterized in that: Two movable windows (312) are provided on the same horizontal plane of the frame (31) and are symmetrically distributed with respect to the radial direction of the frame (31).

9. The microseismic signal acquisition device for oil wells according to claim 8, characterized in that: The movable windows (312) are provided in two groups radially along the frame (31).

10. The microseismic signal acquisition device for oil wells according to claim 1, characterized in that: The flexible expansion member (34) is an air bag.

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