Petroleum downhole pressure monitoring device and monitoring method

Abstract

The invention relates to the technical field of pressure monitoring meters, and provides a petroleum downhole pressure monitoring device and method.The petroleum downhole pressure monitoring device comprises a connecting sleeve, a supporting and righting mechanism and a communicating mechanism, and the connecting sleeve is slidably connected with a pressure monitoring mechanism; the pressure monitoring mechanism is used for monitoring pressure in an oil well, the supporting and righting mechanism is used for supporting the inner wall of the oil well, the communicating mechanism is in sliding connection with the supporting and righting mechanism and used for communicating the pressure monitoring mechanism with the interior of the oil well, and the communicating mechanism and the supporting and righting mechanism are arranged on the pressure monitoring mechanism in a sleeving mode. After the supporting and righting mechanism is opened to support the inner wall of the oil well, the communicating mechanism is opened to enable the interior of the oil well to be communicated with the pressure monitoring mechanism, and through the technical scheme, the problem that in the prior art, a mechanical pressure gauge is likely to be attached to the wall of the oil well when pressure monitoring is conducted under the oil well is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure monitoring meters, and in particular to a downhole oil pressure monitoring device and a monitoring method. Background Art

[0002] Pressure monitoring in oil wells is a key link in the process of oil exploration, development and production. Its role runs through the entire life cycle of the oil well. The pressure monitoring data can be used to evaluate the permeability, porosity and pressure distribution of the reservoir, calculate the recoverable reserves, understand the production status of the oil well at all times through pressure changes, and adjust the production speed. Therefore, whether the pressure in the oil well can be accurately monitored is crucial to the production of the oil well. The pressure monitoring devices currently used mainly include mechanical pressure gauges, electronic pressure gauges, fiber optic pressure gauges, etc. Among them, mechanical pressure gauges have the advantages of simple structure, low cost and high reliability. Although the accuracy and flexibility are relatively low, they are still widely used.

[0003] When using a mechanical pressure gauge, the lifting device lowers the pressure gauge into the oil well by hoisting, and the pressure is monitored when it reaches the depth that needs to be monitored. However, since there are many impurities attached to the inner wall of the oil well, including mud, wax, sand, corrosion products and other impurities, the impurities may clog the pressure gauge during monitoring, resulting in measurement errors. In addition, since most oil wells have a certain inclination, the pressure gauge may contact the well wall, which will also cause inaccurate measurement position and data. Summary of the invention

[0004] The present invention provides a downhole oil pressure monitoring device and a monitoring method, which solves the problem that a mechanical pressure gauge in the prior art may adhere to the wall of the oil well when monitoring the downhole oil well pressure.

[0005] The technical solution of the present invention is as follows: A downhole oil pressure monitoring device comprises a sling, which is connected to a lifting device, and further comprises a connecting sleeve, a supporting and straightening mechanism and a connecting mechanism, wherein the connecting sleeve is fixedly connected to the sling, a pressure monitoring mechanism is slidably connected to the connecting sleeve, and the pressure monitoring mechanism is used to monitor the pressure in the oil well, wherein the pressure monitoring mechanism comprises a sliding sleeve and a fixing seat, wherein the sliding sleeve is slidably connected to the connecting sleeve, the connecting sleeve is arranged inside the sliding sleeve, the fixing seat is fixedly connected to the sliding sleeve, and the supporting and straightening mechanism is fixedly connected to the connecting sleeve. The supporting and straightening mechanism is used to support the inner wall of the oil well, and the supporting and straightening mechanism includes a support arm and an open frame assembly. There are multiple support arms, and multiple support arms are fixedly connected to the connecting sleeve on one side close to the sling. There are multiple open frame assemblies, and each of the support arms is connected to the open frame assembly. The open frame assembly is used to support the inner wall of the oil well. The connecting mechanism is fixedly connected to the pressure monitoring mechanism, and the connecting mechanism is slidably connected to the supporting and straightening mechanism. The connecting mechanism is used to connect the pressure monitoring mechanism with the inside of the oil well.

[0006] The pressure monitoring mechanism also includes a protective cylinder, a pressure gauge is fixedly mounted on the fixed seat, the protective cylinder is fixedly connected to the fixed seat, the protective cylinder is sleeved on the pressure gauge, a through hole is provided on the side of the protective cylinder close to the fixed seat, a conical wire take-up reel is provided on the sliding sleeve, the conical wire take-up reel is fixedly connected to the fixed seat, and the sliding sleeve, the conical wire take-up reel and the center of the fixed seat are interconnected.

[0007] A cable is fixedly connected to the pressure gauge, and the cable passes through the fixed seat, the conical wire take-up drum and the sliding sleeve. The cable is fixedly connected to the connecting sleeve. When the connecting sleeve slides toward the conical wire take-up drum in the sliding sleeve, the cable is curled and stored in the conical wire take-up drum.

[0008] The support and straightening mechanism also includes a cover body and a drive cylinder, the cover body is fixedly arranged on the support arm, the cover body is sleeved on the opening frame assembly, a plurality of drive cylinders are provided, and a plurality of the drive cylinders are fixedly arranged on the connecting mechanism, and a support plate is fixedly connected to the output ends of the plurality of drive cylinders, and the support plate is fixedly connected to the plurality of support arms. The opening frame assembly includes an opening sleeve, a docking groove, a sliding groove, a support rod and a rack, the opening sleeve is sleeved on the sliding sleeve, the docking groove is arranged on the outer side of the opening sleeve, the sliding groove is arranged on the opening sleeve, the sliding groove and the docking groove are connected, the support rod is rotatably connected to the sliding groove, a gear is arranged on the support rod, the support rod can be rotatably docked to the docking groove, the rack is slidably connected to the sliding groove, the rack is meshed with the gear, the rack is fixedly connected to the support arm, and an arc segment is arranged on the end of the support rod away from the gear, and a rubber gasket is arranged on the arc segment.

[0009] The connecting mechanism and the supporting and straightening mechanism are both mounted on the pressure monitoring mechanism. After the supporting and straightening mechanism is opened to support the inner wall of the oil well, the connecting mechanism is opened to connect the inside of the oil well with the pressure monitoring mechanism. The connecting mechanism includes a docking barrel and a sliding rod. The docking barrel is fixedly connected to the protective cylinder. The docking barrel is slidably connected to the open sleeve. The sliding rod is fixedly connected to the open sleeve. The sliding rod is slidably connected to the docking barrel. A spring is mounted on the sliding rod. The two ends of the spring are respectively fixedly connected to the docking barrel and the open sleeve. A plurality of connecting holes are opened on the docking barrel. The pressure gauge can be connected to the oil well through the connecting holes.

[0010] A method for monitoring downhole oil pressure, using the above-mentioned downhole oil pressure monitoring device, comprises the following steps: Step 1: Lowering into place: The lifting device lowers the connecting sleeve downward in the oil well through the sling, and stops lowering after it reaches a specified height; Step 2, pull the support apart: the output end of the driving cylinder extends to push the support sheet, the support sheet pushes the support arm to pull the rack to move, the rack slides in the sliding groove, and the rack drives the gear to rotate; Step 3, support and fixation: the gear drives the support rod to rotate, the support rod is separated from the docking groove, the rubber gasket contacts the inner wall of the oil well, and when all the support rods are in contact with the inner wall of the oil well, the rack stops sliding; Step 4, connection monitoring: when the rack stops sliding, the output end of the driving cylinder extends to push the docking barrel and the open sleeve to slide and separate, and the connecting hole is separated from the open sleeve; Step 5, monitoring completed: the pressure gauge is connected to the oil well through the protective tube and the connecting hole, and the pressure gauge can perform pressure monitoring. After the detection is completed, the output end of the driving cylinder is shortened.

[0011] The working principle and beneficial effects of the present invention are: 1. In the present invention, by setting a rack and a support rod, when the driving cylinder pushes the support arm to pull the rack to move, the support rod rotates to leave the docking groove, and at this time the support rod is staggered with the bar groove on the cover body, and when the rack slides, the gears on both sides of the support rod are driven to rotate, so that the support rod rotates, and the arc section on the support rod can support the inner wall of the oil well, reducing the possibility of the support rod slipping on the inner wall of the oil well. After the support rod is opened, the rubber gasket first contacts the inner wall of the oil well, and through the rubber gasket, the support rod can contact the inner wall of the oil well through multiple angles, and at the same time, the possibility of the support rod slipping is reduced. Due to the accumulation of impurities in the oil well, the inner diameters at different positions in the oil well may be different. When the rack drives the support rod to rotate to the maximum angle and stops rotating, the docking barrel begins to slide, and because the angles of the support rod opening may be different, the rubber gasket enables the support rod to increase the stability of support at multiple angles. When the four support rods all support the inner wall of the oil well, the pressure gauge is in the center of the oil well and will not contact with impurities. 2. In the present invention, by providing a supporting and straightening mechanism, the support rod can support the inner wall of the oil well, keep the pressure gauge in the center of the oil well, and avoid contact between the pressure gauge and impurities on the inner wall of the oil well during pressure testing. By providing a connecting mechanism, after the support rod supports the pressure gauge in the center of the oil well, the open sleeve and the oil well can be connected through the connecting hole, and then pressure testing can be performed, thereby avoiding contact with impurities during testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0013] Figure 1 It is a schematic diagram of the structure of the present invention in an overall opened state; Figure 2 It is a schematic diagram of the overall structure of the present invention; Figure 3 It is a schematic diagram of the internal cross-sectional structure of the supporting arm and the open sleeve in the present invention; Figure 4 It is a schematic diagram of the internal cross-sectional structure of the open sleeve in the present invention; Figure 5 It is a schematic diagram of the exploded internal cross-sectional structure of the connecting sleeve and the sliding sleeve in the present invention; Figure 6 It is a schematic diagram of the internal cross-sectional structure of the slide rod and the drive cylinder in the present invention; Figure 7It is a schematic diagram of the internal cross-sectional structure of the support rod in the present invention when it is rotated and opened; Figure 8 It is a cross-sectional structural schematic diagram of the support rod and the rack matching in the present invention; Fig. 9 It is a cross-sectional structural schematic diagram of another viewing angle of the matching between the support rod and the rack in the present invention.

[0014] In the figure: 1. sling; 2. connecting sleeve; 3. sliding sleeve; 4. fixing seat; 5. protective cylinder; 6. conical wire reel; 7. cable; 8. support arm; 9. cover; 10. driving cylinder; 11. supporting plate; 12. opening sleeve; 13. docking groove; 14. sliding groove; 15. supporting rod; 16. rack; 17. docking barrel; 18. sliding rod; 19. spring; 20. connecting hole; 21. rubber gasket; 22. pressure gauge. DETAILED DESCRIPTION

[0015] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions 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 are within the scope of protection of the present invention.

[0016] Embodiment 1 like Figures 1 to 9 As shown, this embodiment proposes a downhole oil pressure monitoring device, including a sling 1, which is connected to a lifting device, and also includes a connecting sleeve 2, a supporting and straightening mechanism and a connecting mechanism. The connecting sleeve 2 is fixedly connected to the sling 1, and a pressure monitoring mechanism is slidably connected to the connecting sleeve 2. The pressure monitoring mechanism is used to monitor the pressure in the oil well. The pressure monitoring mechanism includes a sliding sleeve 3 slidably connected to the connecting sleeve 2, the connecting sleeve 2 is arranged inside the sliding sleeve 3, and a fixed seat 4 is fixedly connected to the sliding sleeve 3. The supporting and straightening mechanism is fixedly connected to the connecting sleeve 2, and the supporting and straightening mechanism is used to support the inner wall of the oil well. The supporting and straightening mechanism includes a plurality of supporting arms 8, and the plurality of supporting arms 8 are fixedly connected to the connecting sleeve 2 on one side close to the sling 1. A plurality of open frame assemblies are provided, and each supporting arm 8 is connected to the open frame assembly. The open frame assembly is used to support the inner wall of the oil well. The connecting mechanism is fixedly connected to the pressure monitoring mechanism, and the connecting mechanism is slidably connected to the supporting and straightening mechanism. The connecting mechanism is used to connect the pressure monitoring mechanism with the inside of the oil well.

[0017] like Figures 1 to 5As shown, the pressure monitoring mechanism also includes a protective tube 5, a pressure gauge 22 is fixedly installed on the fixed seat 4, the protective tube 5 is fixedly connected to the fixed seat 4, the protective tube 5 is sleeved on the pressure gauge 22, a through hole is provided on the side of the protective tube 5 close to the fixed seat 4, a conical take-up drum 6 is provided on the sliding sleeve 3, the conical take-up drum 6 is fixedly connected to the fixed seat 4, the sliding sleeve 3, the conical take-up drum 6 and the fixed seat 4 are connected to each other in the center, the pressure gauge 22 is in the protective tube 5, which can prevent the pressure gauge 22 from contacting with impurities on the wall of the oil well, and the pressure gauge 22 is connected to the outside through the through hole on the protective tube 5, which does not affect the pressure monitoring.

[0018] like Figures 4 to 6 As shown, a cable 7 is fixedly connected to the pressure gauge 22, and the cable 7 passes through the fixed seat 4, the conical take-up reel 6 and the sliding sleeve 3. The cable 7 is fixedly connected to the connecting sleeve 2. When the connecting sleeve 2 slides toward the conical take-up reel 6 in the sliding sleeve 3, the cable 7 is curled and stored in the conical take-up reel 6. When the connecting sleeve 2 and the sliding sleeve 3 slide against each other, the distance between the connecting sleeve 2 and the pressure gauge 22 changes. The pressure gauge 22 needs to be connected to a transmission wire or a signal wire. By storing part of the wire in the conical take-up reel 6, the wire can be prevented from being pulled and broken.

[0019] like Figures 4 to 9As shown, the supporting and straightening mechanism also includes a cover body 9 and a driving cylinder 10, the cover body 9 is fixedly arranged on the support arm 8, the cover body 9 is sleeved on the opening frame assembly, a plurality of driving cylinders 10 are provided, and the plurality of driving cylinders 10 are fixedly arranged on the connecting mechanism, and a supporting sheet 11 is fixedly connected to the output end of the plurality of driving cylinders 10, and the supporting sheet 11 is fixedly connected to the plurality of support arms 8, and the opening frame assembly includes an opening sleeve 12, a docking groove 13, a sliding groove 14, a supporting rod 15 and a rack 16, the opening sleeve 12 is sleeved on the sliding sleeve 3, the docking groove 13 is arranged on the outside of the opening sleeve 12, and the sliding groove 14 is arranged on the opening sleeve 12. On the open sleeve 12, the sliding groove 14 is connected to the docking groove 13, the support rod 15 is rotatably connected to the sliding groove 14, a gear is provided on the support rod 15, the support rod 15 can be rotatably docked to the docking groove 13, the rack 16 is slidably connected to the sliding groove 14, the rack 16 is meshed with the gear, the rack 16 is fixedly connected to the support arm 8, an arc segment is provided on the end of the support rod 15 away from the gear, and a rubber gasket 21 is provided on the arc segment. In this embodiment, four opening frame assemblies are provided, and four support arms 8 are also provided. A strip groove corresponding to the support rod 15 is provided on the cover body 9. When the drive cylinder When the support arm 8 is pushed by the support arm 8 and the rack 16 is pulled to move, the support rod 15 rotates to leave the docking groove 13. At this time, the support rod 15 is staggered with the bar groove on the cover body 9. The rack 16 is arranged on the side of the sliding groove 14 close to the docking groove 13. The support rod 15 passes through the rack 16. When the rack 16 slides, the gears on both sides of the support rod 15 are driven to rotate, so that the support rod 15 rotates. The arc section on the support rod 15 can support the inner wall of the oil well, reducing the possibility of the support rod 15 slipping on the inner wall of the oil well. After the support rod 15 is opened, the rubber gasket 21 first contacts the inner wall of the oil well, and through the rubber gasket 21, the support rod 15 is rotated. The support rod 15 can contact the inner wall of the oil well at multiple angles, while reducing the possibility of the support rod 15 slipping. Due to the accumulation of impurities in the oil well, the inner diameters at different positions in the oil well may be different. When the rack 16 drives the support rod 15 to rotate to the maximum angle and then stops rotating, the docking barrel 17 begins to slide. Since the opening angles of the support rod 15 may be different, the rubber gasket 21 enables the support rod 15 to increase the support stability at multiple angles. When the four support rods 15 all support the inner wall of the oil well, the pressure gauge 22 is in the center of the oil well and will not contact with impurities.

[0020] like Figures 4 to 7As shown, the connecting mechanism and the supporting and straightening mechanism are both sleeved on the pressure monitoring mechanism. After the supporting and straightening mechanism is opened to support the inner wall of the oil well, the connecting mechanism is opened to connect the inside of the oil well with the pressure monitoring mechanism. The connecting mechanism includes a docking barrel 17 and a sliding rod 18. The docking barrel 17 is fixedly connected to the protective tube 5. The docking barrel 17 is slidably connected to the open sleeve 12. The sliding rod 18 is fixedly connected to the open sleeve 12. The sliding rod 18 is slidably connected to the docking barrel 17. A spring 19 is sleeved on the sliding rod 18. The two ends of the spring 19 are respectively fixedly connected to the docking barrel 17 and the open sleeve 12. The docking barrel 17 is provided with a spring 19. There are multiple connecting holes 20, through which the pressure gauge 22 can be connected to the oil well. The spring 19 pulls the docking barrel 17 and the opening sleeve 12, so that when the rack 16 pulls the support rod 15 to rotate and open to support the inner wall of the oil well and cannot rotate, the rack 16 will pull the opening sleeve 12 to slide. At this time, the spring 19 is stretched and elongated to slide the docking barrel 17, and the connecting hole 20 is gradually separated from the opening sleeve 12. At this time, the pressure gauge 22 can monitor the pressure, and when the output end of the driving cylinder 10 is shortened, the spring 19 shortens and can pull the docking barrel 17 and the opening sleeve 12 to slide and reset.

[0021] In this embodiment, by completely sealing the outside of the pressure gauge 22, the pressure gauge 22 can be prevented from contacting with impurities on the inner wall of the oil well during movement and affecting the monitoring results. When placed in a suitable position, the inner wall of the oil well is supported by rotating four support rods 15 to keep the pressure gauge 22 in the center of the oil well. Then the docking barrel 17 is separated from the open sleeve 12, and the connecting hole 20 is opened. At this time, the pressure gauge 22 can detect the pressure inside the oil well. After the pressure gauge 22 is supported to the center of the oil well, the connecting hole 20 is opened, so that impurities will not contact the pressure gauge 22.

[0022] Embodiment 2 A method for monitoring downhole oil pressure, using the above-mentioned downhole oil pressure monitoring device, comprises the following steps: Step 1: Lowering into place: The lifting device lowers the connecting sleeve 2 in the oil well through the sling 1, and stops lowering after it reaches the specified height; Step 2: Pull the support apart: the output end of the driving cylinder 10 extends to push the support sheet 11, the support sheet 11 pushes the support arm 8 to pull the rack 16 to move, the rack 16 slides in the sliding groove 14, and the rack 16 drives the gear to rotate; Step 3, support and fixation: the gear drives the support rod 15 to rotate, the support rod 15 is separated from the docking groove 13, and the rubber gasket 21 contacts the inner wall of the oil well. When all the support rods 15 are in contact with the inner wall of the oil well, the rack 16 stops sliding; Step 4: Connectivity monitoring: When the rack 16 stops sliding, the output end of the drive cylinder 10 extends to push the docking barrel 17 to slide and separate from the open sleeve 12, and the connecting hole 20 is separated from the open sleeve 12; Step 5, monitoring completed: the pressure gauge 22 is connected to the oil well through the protective tube 5 and the connecting hole 20, and the pressure gauge 22 can perform pressure monitoring. After the detection is completed, the output end of the driving cylinder 10 is shortened.

[0023] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A downhole oil pressure monitoring device, comprising a sling (1), wherein the sling (1) is connected to a lifting device, and characterized in that: Also includes: A connecting sleeve (2), the connecting sleeve (2) and the sling (1) are fixedly connected, a pressure monitoring mechanism is slidably connected to the connecting sleeve (2), the pressure monitoring mechanism is used to monitor the pressure in the oil well, the pressure monitoring mechanism comprises a sliding sleeve (3) and a fixing seat (4), the sliding sleeve (3) is slidably connected to the connecting sleeve (2), the connecting sleeve (2) is arranged inside the sliding sleeve (3), and the fixing seat (4) is fixedly connected to the sliding sleeve (3); A support and straightening mechanism, the support and straightening mechanism is fixedly connected to the connecting sleeve (2), the support and straightening mechanism is used to support the inner wall of the oil well, the support and straightening mechanism comprises a support arm (8) and an open frame assembly, a plurality of the support arms (8) are provided, a plurality of the support arms (8) are fixedly connected to the connecting sleeve (2) on one side close to the sling (1), a plurality of the open frame assemblies are provided, each of the support arms (8) is connected to the open frame assembly, and the open frame assembly is used to support the inner wall of the oil well; A connecting mechanism, wherein the connecting mechanism is fixedly connected to the pressure monitoring mechanism, the connecting mechanism is slidably connected to the supporting and straightening mechanism, and the connecting mechanism is used to connect the pressure monitoring mechanism with the inside of the oil well.

2. A downhole oil pressure monitoring device according to claim 1, characterized in that: The pressure monitoring mechanism also includes: A pressure gauge (22) is fixedly mounted on the fixing seat (4); A protective tube (5), the protective tube (5) being fixedly connected to the fixing seat (4), the protective tube (5) being sleeved on the pressure gauge (22), and a through hole being provided on a side of the protective tube (5) close to the fixing seat (4).

3. A downhole oil pressure monitoring device according to claim 2, characterized in that: A conical wire take-up drum (6) is provided on the sliding sleeve (3), the conical wire take-up drum (6) is fixedly connected to the fixed seat (4), and the sliding sleeve (3), the conical wire take-up drum (6) and the fixed seat (4) are interconnected at their centers.

4. A downhole oil pressure monitoring device according to claim 3, characterized in that: A cable (7) is fixedly connected to the pressure gauge (22), the cable (7) passes through the fixed seat (4), the conical wire take-up drum (6) and the sliding sleeve (3), and the cable (7) is fixedly connected to the connecting sleeve (2). When the connecting sleeve (2) slides toward the conical wire take-up drum (6) in the sliding sleeve (3), the cable (7) is curled and stored in the conical wire take-up drum (6).

5. A downhole oil pressure monitoring device according to claim 4, characterized in that: The supporting and straightening mechanism further comprises: a cover body (9), the cover body (9) being fixedly arranged on the support arm (8), and the cover body (9) being sleeved on the opening frame assembly; A driving cylinder (10), wherein a plurality of the driving cylinders (10) are provided, the plurality of driving cylinders (10) are fixedly arranged on the connecting mechanism, a supporting sheet (11) is fixedly connected to the output ends of the plurality of driving cylinders (10), and the supporting sheet (11) is fixedly connected to the plurality of supporting arms (8).

6. A downhole oil pressure monitoring device according to claim 5, characterized in that: The opening frame assembly comprises: An opening sleeve (12), wherein the opening sleeve (12) is sleeved on the sliding sleeve (3); A docking groove (13), wherein the docking groove (13) is formed on the outer side of the open sleeve (12); A sliding groove (14), the sliding groove (14) being formed on the opening sleeve (12), the sliding groove (14) being in communication with the docking groove (13); A support rod (15), the support rod (15) being rotatably connected to the sliding groove (14), the support rod (15) being provided with a gear, and the support rod (15) being capable of rotatably docking with the docking groove (13); A rack (16), the rack (16) is slidably connected in the sliding groove (14), the rack (16) is meshed with the gear, and the rack (16) is fixedly connected to the support arm (8).

7. A downhole oil pressure monitoring device according to claim 6, characterized in that: The connecting mechanism and the supporting and straightening mechanism are both sleeved on the pressure monitoring mechanism. After the supporting and straightening mechanism is opened to support the inner wall of the oil well, the connecting mechanism is opened to connect the inside of the oil well with the pressure monitoring mechanism. The connecting mechanism includes: A docking barrel (17), the docking barrel (17) being fixedly connected to the protective barrel (5), and the docking barrel (17) being slidably connected to the open sleeve (12); A slide rod (18), the slide rod (18) being fixedly connected to the opening sleeve (12), the slide rod (18) being slidably connected to the docking barrel (17), a spring (19) being sleeved on the slide rod (18), and two ends of the spring (19) being fixedly connected to the docking barrel (17) and the opening sleeve (12), respectively.

8. The oil well downhole pressure monitoring device according to claim 7, characterized in that: The docking barrel (17) is provided with a plurality of communication holes (20), through which the pressure gauge (22) can be connected to the oil well.

9. The oil well downhole pressure monitoring device according to claim 8, characterized in that: An arc section is provided on one end of the support rod (15) away from the gear, and a rubber gasket (21) is provided on the arc section.

10. A method for monitoring downhole oil pressure, using the downhole oil pressure monitoring device according to claim 9, characterized in that: The following steps are involved: S1, lowering into place: the lifting device lowers the connecting sleeve (2) downward in the oil well through the sling (1), and stops lowering after it reaches a specified height; S2, pulling the support apart: the output end of the driving cylinder (10) extends to push the support plate (11), the support plate (11) pushes the support arm (8) to pull the rack (16) to move, the rack (16) slides in the sliding groove (14), and the rack (16) drives the gear to rotate; S3, supporting and fixing: the gear drives the support rod (15) to rotate, the support rod (15) is separated from the docking groove (13), the rubber gasket (21) contacts the inner wall of the oil well, and when all the support rods (15) are in contact with the inner wall of the oil well, the rack (16) stops sliding; S4, connection monitoring: when the rack (16) stops sliding, the output end of the drive cylinder (10) extends to push the docking barrel (17) and the open sleeve (12) to slide and separate, and the connecting hole (20) is separated from the open sleeve (12); S5, monitoring completed: the pressure gauge (22) is connected to the oil well through the protective tube (5) and the connecting hole (20), and the pressure gauge (22) can perform pressure monitoring. After the detection is completed, the output end of the driving cylinder (10) is shortened.

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