Special pressure test tool for petroleum downhole operation

Abstract

The utility model discloses a special pressure test tool for petroleum downhole operation, which comprises a U-shaped seat, the top of the U-shaped seat is fixedly connected with a mounting plate, a rectangular lower connecting cylinder and a rectangular upper connecting cylinder are arranged in the U-shaped seat, the rectangular lower connecting cylinder is fixedly connected with the inner wall of the bottom of the U-shaped seat, and the rectangular upper connecting cylinder is fixedly connected with the inner wall of the bottom of the U-shaped seat. Openings are formed in the sides, close to each other, of the rectangular lower connecting cylinder and the rectangular upper connecting cylinder, and a rectangular elastic sealing ring is fixedly bonded to the bottom of the rectangular upper connecting cylinder. Through the arrangement of a series of structures, stable pressure control sealing between the rectangular upper connecting cylinder and the rectangular lower connecting cylinder can be achieved, when the reacting force is large and the sealing performance is reduced, the extrusion force can be automatically increased for stable sealing, the pressure control sealing stability is improved, personnel can conveniently and accurately control the pressure value, and the working efficiency is improved. Therefore, personnel can conveniently, intuitively and clearly know the conditions of the petroleum underground operation equipment under different air pressures, and the pressure test accuracy is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of special pressure testing tools, in particular to a special pressure testing tool for underground petroleum operations. Background Art

[0002] Pressure testing refers to the process of testing the pressure resistance of wellhead equipment and ground facilities. There are two types of pressure testing devices for existing downhole testing tools, one is a fixed bench type and the other is a simple bench type. The fixed bench type has high manufacturing costs, is immovable, and is inconvenient to use. The simple bench type has a simple structure, non-standard and irregular design, and is unsafe to use. The existing tools have a small scope of application and are inconvenient to operate. During the pressure test, the connection between the cover body and the shell must withstand a large pressure load, and there is no automatic pressure relief device. Once the cover body is separated from the shell, it is easy to hit the human body, which will cause serious harm to the human body. For this purpose, the application number is: 202122319247.8, which discloses a special tool for downhole oil well operation pressure testing, wherein the top two ends of the base are fixedly connected with a support frame, The top of the support frame is fixedly connected to a support plate, a lower connecting tube is fixedly installed in the middle position of the top of the base, the top of the lower connecting tube is meshedly connected to an upper connecting tube, the top of the upper connecting tube is fixedly connected to a top plate, and electric telescopic rods are fixedly connected between the two sides of the top plate and the support plate, a valve core and a valve seat are arranged inside the upper connecting tube, a conical hole matching the size of the valve core is opened on the valve seat, an upper righting ring and a lower righting ring are arranged below the valve seat, and liquid flow holes are opened on the upper righting ring and the lower righting ring; the device has a simple structure and is easy to operate. By arranging the valve core, valve seat, threaded rod, spring and pressure relief joint, the safety and stability of the device during the pressure test can be ensured, and the device is easy to operate, reliable in operation and safe in use;

[0003] The special tool for pressure testing of oil well operations disclosed in the above patent drives the piston to move downward so that the valve core is combined with the tapered hole on the valve seat, the seal is compressed, and the air pressure in the upper connecting tube and the lower connecting tube increases until the design pressure is reached, and the object to be tested is pressure tested. After the test, the pressure relief valve on the pressure relief joint is opened to perform the pressure relief operation; the special tool for pressure testing disclosed in the above patent still has some shortcomings during use: 1. During the pressure test, it is impossible to accurately control the pressure value inside the test connecting tube and the change of the object to be tested under high pressure, and the pressure test accuracy is not ideal; 2. The sealing connection between the upper connecting tube and the lower connecting tube by a simple elastic sealing ring cannot perform stable pressure control sealing. There is a situation where the sealing ring is pressed upward under the reaction force due to the large pressure inside the connecting tube, resulting in an unstable sealing connection. Based on the above situation, we propose a special tool for pressure testing of oil well operations. Utility Model Content

[0004] The utility model aims to solve the shortcomings in the prior art and proposes a special tool for testing pressure in underground oil well operations.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A special tool for testing pressure in oil well operations comprises a U-shaped seat, the top of the U-shaped seat is fixedly connected to a mounting plate, a rectangular lower connecting tube and a rectangular upper connecting tube are arranged in the U-shaped seat, the rectangular lower connecting tube is fixedly connected to the bottom inner wall of the U-shaped seat, the sides of the rectangular lower connecting tube and the rectangular upper connecting tube close to each other are both set as openings, a rectangular elastic sealing ring is bonded and fixed to the bottom of the rectangular upper connecting tube, the bottom of the rectangular elastic sealing ring is in close contact with the top of the rectangular lower connecting tube, and the sealing between the rectangular upper connecting tube and the rectangular lower connecting tube is achieved by the rectangular elastic sealing ring, the outer side of the rectangular elastic sealing ring and the outer side of the rectangular upper connecting tube are fixedly connected with the same elastic tightening detection mechanism, the elastic tightening detection mechanism is fixedly sleeved on the rectangular lower connecting tube, the rectangular elastic sealing ring is elastically tightened by the elastic tightening detection mechanism to improve the sealing stability, both sides of the rectangular upper connecting tube are fixedly connected with vertical driving mechanisms, the mounting plate is fixedly sleeved on the two vertical driving mechanisms, and the vertical driving mechanism is used to drive the rectangular upper connecting tube to move vertically The U-shaped seat is fixedly connected to the upper rectangular connecting tube, and the top of the U-shaped seat is fixedly connected to the first electric telescopic rod whose output shaft is fixedly connected to the top of the piston. The piston and the first electric telescopic rod cooperate to squeeze the gas to increase the air pressure inside the rectangular upper connecting tube and the rectangular lower connecting tube. The left side of the U-shaped seat is fixedly connected to a display screen, and the top of the display screen is fixedly connected to a PLC controller. The left side of the rectangular lower connecting tube is fixedly connected to an air pressure sensor, and the air pressure sensor is used to monitor the air pressure inside the rectangular lower connecting tube. A tilted camera is fixedly installed on the right side of the rectangular lower connecting tube, and the camera is used to monitor the situation inside the rectangular lower connecting tube. The right bottom of the rectangular lower connecting tube is connected and fixed with an electromagnetic valve, and the electromagnetic valve is used for deflation and pressure reduction operations. The air pressure sensor, the electromagnetic valve, the elastic tension detection mechanism and the vertical drive mechanism are all electrically connected to the PLC controller, and the camera and the air pressure sensor are all electrically connected to the display screen. The information detected by the camera and the air pressure sensor is displayed on the display screen.

[0007] Preferably, the elastic tensioning detection mechanism comprises a first circular frame fixedly sleeved on a rectangular elastic sealing ring, a second circular frame fixedly sleeved on a rectangular lower connecting tube, two guide blocks fixedly connected on both sides of the rectangular upper connecting tube, two L-shaped guide rods fixedly connected on both sides of the top of the first circular frame, the guide blocks are slidably sleeved on the corresponding L-shaped guide rods, the L-shaped guide rods and the guide blocks cooperate to provide vertical guidance for the first circular frame, a compression spring in a compressed state is fixedly connected between the bottom of the guide block and the top of the first circular frame, the compression spring is movably sleeved on the corresponding L-shaped guide rod, the compression spring in a compressed state will always have a downward tensioning force, thereby exerting a downward tensioning force on the first circular frame, pressure sensors are embedded and fixed on both sides of the bottom of the first circular frame, the pressure sensors are used to detect the tensioning extrusion force, the bottom of the pressure sensor is a detection end and is movably in contact with the top of the second circular frame, and the two pressure sensors are electrically connected to the PLC controller.

[0008] Preferably, the vertical driving mechanism includes a moving block, and the sides of the two moving blocks close to each other are fixedly connected to the tops of both sides of the rectangular upper connecting tube, respectively; two second electric telescopic rods are embedded and fixed at the bottom of the mounting plate, and the bottom ends of the output shafts of the second electric telescopic rods are fixedly connected to the tops of the corresponding moving blocks; a synchronous control switch is fixedly connected to the rear side of the second electric telescopic rod on the left, and the synchronous control switch is electrically connected to the two second electric telescopic rods and the PLC controller, and the synchronous control switch is used to control the two second electric telescopic rods to open synchronously.

[0009] Preferably, the outer bonding sleeve of the piston is provided with a sealing sleeve, the outer side of the sealing sleeve is in active contact with the inner wall of the rectangular upper connecting cylinder, and the sealing between the piston and the rectangular upper connecting cylinder is achieved through the sealing sleeve.

[0010] Preferably, a avoidance hole with an opening at the front side is provided on the top of the mounting plate, and the first electric telescopic rod is located in the avoidance hole and does not contact the inner wall of the avoidance hole.

[0011] Preferably, a mounting block is fixedly mounted on the right side of the rectangular lower connecting tube, the bottom of the mounting block is fixedly connected to the top of the camera, and the rectangular lower connecting tube and the rectangular upper connecting tube are both made of transparent material.

[0012] Preferably, the camera and the air pressure sensor are both equipped with a built-in signal sending module, the display screen is equipped with a built-in display module and a signal receiving module, and the signal sending module is connected to the signal receiving module.

[0013] Compared with the existing technology, the beneficial effects of the utility model are:

[0014] 1. Through the coordination of the elastic tightening detection mechanism, the vertical driving mechanism and the PLC controller, the rectangular elastic sealing ring can be pressure-controlled and squeezed. The compression spring in the compressed state will always give the rectangular elastic sealing ring a downward tightening force through the first round frame, thereby realizing a stable pressure-controlled seal between the rectangular upper connecting tube and the rectangular lower connecting tube. When the air pressure is large and the reaction force is large, resulting in reduced sealing, the squeezing force can be automatically increased to achieve stable sealing, thereby improving the stability of the pressure-controlled seal and reducing the situation where the sealing connection is unstable due to the large reaction force.

[0015] 2. Through the combination of camera, air pressure sensor, PLC controller and display screen, it is convenient for personnel to accurately control the pressure value, so that personnel can intuitively and clearly know the situation of oil well operation equipment under different air pressures, improve the accuracy of pressure test, and can automatically reduce the pressure when the air pressure value is high, reducing the safety hazards caused by the high air pressure value;

[0016] The utility model can realize stable pressure-controlled sealing between the rectangular upper connecting tube and the rectangular lower connecting tube through the arrangement of a series of structures, and can automatically increase the extrusion force to perform stable sealing when the reaction force is large, resulting in reduced sealing performance, thereby improving the stability of the pressure-controlled sealing and facilitating personnel to accurately control the pressure value, thereby facilitating personnel to intuitively and clearly know the conditions of the oil well operating equipment under different air pressures, thereby improving the accuracy of the pressure test. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a three-dimensional structural schematic diagram of a special tool for testing pressure in oil wells proposed by the utility model;

[0018] Figure 2 This is a top-down perspective structural diagram of a special tool for testing pressure in oil wells proposed by the utility model;

[0019] Figure 3 This is a schematic diagram of the main cross-sectional structure of a special tool for testing pressure in underground oil wells proposed by the utility model;

[0020] Figure 4 for Figure 3 Schematic diagram of the enlarged structure of part A.

[0021] In the figure: 100, U-shaped seat; 101, rectangular upper connecting tube; 102, rectangular lower connecting tube; 103, mounting plate; 104, piston; 1, second electric telescopic rod; 2, moving block; 3, first electric telescopic rod; 4, air pressure sensor; 5, solenoid valve; 6, camera; 7, display screen; 8, PLC controller; 9, rectangular elastic sealing ring; 10, second round frame; 11, first round frame; 12, pressure sensor; 13, guide block; 14, L-shaped guide rod; 15, compression spring. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention will be described clearly and completely 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, rather than all of the embodiments.

[0023] Reference Figure 1-4 A special tool for testing pressure in oil wells, comprising a U-shaped seat 100, a mounting plate 103 fixedly connected to the top of the U-shaped seat 100, a rectangular lower connecting tube 102 and a rectangular upper connecting tube 101 arranged inside the U-shaped seat 100, the rectangular lower connecting tube 102 being fixedly connected to the bottom inner wall of the U-shaped seat 100, wherein the rectangular lower connecting tube 102 and the rectangular upper connecting tube 101 are both made of transparent materials, which is convenient for personnel to view the internal conditions, the sides of the rectangular lower connecting tube 102 and the rectangular upper connecting tube 101 close to each other are both set as openings, and the bottom of the rectangular upper connecting tube 101 is bonded and fixed with A rectangular elastic sealing ring 9, the bottom of which is in close contact with the top of the rectangular lower connecting tube 102, and the sealing between the rectangular upper connecting tube 101 and the rectangular lower connecting tube 102 is realized by the rectangular elastic sealing ring 9, the outer side of the rectangular elastic sealing ring 9 and the outer side of the rectangular upper connecting tube 101 are fixedly connected with the same elastic tightening detection mechanism, the elastic tightening detection mechanism is fixedly sleeved on the rectangular lower connecting tube 102, the elastic tightening detection mechanism includes a first circular frame 11 fixedly sleeved on the rectangular elastic sealing ring 9, and a second circular frame 11 is fixedly sleeved on the rectangular lower connecting tube 102 0, two guide blocks 13 are fixedly connected to both sides of the rectangular upper connecting cylinder 101, and two L-shaped guide rods 14 are fixedly connected to both sides of the top of the first circular frame 11. The guide blocks 13 are slidably sleeved on the corresponding L-shaped guide rods 14, wherein a guide hole is opened on the top of the guide block 13, and the inner wall of the guide hole is slidably sleeved on the outer side of the corresponding L-shaped guide rod 14. The L-shaped guide rod 14 and the guide block 13 cooperate to play a vertical guiding effect on the first circular frame 11. A compression spring 15 in a compressed state is fixedly connected between the bottom of the guide block 13 and the top of the first circular frame 11. The compression spring 15 is movably sleeved on the corresponding L-shaped guide rod 14. The compression spring 15 in a compressed state will always have a downward tensioning force, thereby exerting a downward tensioning force on the first circular frame 11. Pressure sensors 12 are embedded and fixed on both sides of the bottom of the first circular frame 11, wherein both sides of the bottom of the first circular frame 11 are provided with embedding grooves, and the inner wall of the embedding groove is fixedly connected to the outer side of the corresponding pressure sensor 12. The pressure sensor 12 is used to detect the tightening extrusion force, and the bottom of the pressure sensor 12 is a detection end and is in movably contact with the top of the second circular frame 10;

[0024] Both sides of the rectangular upper connecting tube 101 are fixedly connected with vertical driving mechanisms, and the mounting plate 103 is fixedly sleeved on the two vertical driving mechanisms. The vertical driving mechanism includes a moving block 2, and the sides of the two moving blocks 2 close to each other are respectively fixedly connected to the tops of both sides of the rectangular upper connecting tube 101, and two second electric telescopic rods 1 are embedded and fixed at the bottom of the mounting plate 103, wherein two embedding holes are provided at the top of the mounting plate 103, and the inner walls of the embedding holes are fixedly connected to the outer sides of the corresponding second electric telescopic rods 1, and the bottom end of the output shaft of the second electric telescopic rod 1 is fixedly connected to the top of the corresponding moving block 2, and a synchronous control switch is fixedly connected to the rear side of the second electric telescopic rod 1 on the left side, and the synchronous control switch is electrically connected to the two second electric telescopic rods 1, and the synchronous control switch is used to control the two second electric telescopic rods 1 to be opened synchronously;

[0025] A piston 104 is provided in a sealing movable sleeve in the rectangular upper connecting cylinder 101, wherein a sealing sleeve is provided on the outer bonding sleeve of the piston 104, and the outer side of the sealing sleeve is in movable contact with the inner wall of the rectangular upper connecting cylinder 101, and the sealing sleeve is used to realize the sealing between the piston 104 and the rectangular upper connecting cylinder 101, and the top of the rectangular upper connecting cylinder 101 is fixedly connected with a first electric telescopic rod 3 whose output shaft is fixedly connected to the top of the piston 104, and the piston 104 cooperates with the first electric telescopic rod 3 to squeeze the gas to increase the air pressure inside the rectangular upper connecting cylinder 101 and the rectangular lower connecting cylinder 102, wherein the top of the mounting plate 103 is opened There is an avoidance hole with an opening on the front side, the first electric telescopic rod 3 is located in the avoidance hole and does not contact the inner wall of the avoidance hole, a display screen 7 is fixedly connected to the left side of the U-shaped seat 100, a PLC controller 8 is fixedly connected to the top of the display screen 7, an air pressure sensor 4 is fixedly connected to the left side of the rectangular lower connecting tube 102, and the air pressure sensor 4 is used to monitor the air pressure inside the rectangular lower connecting tube 102, and a camera 6 set obliquely is fixedly installed on the right side of the rectangular lower connecting tube 102, wherein a mounting block is fixedly installed on the right side of the rectangular lower connecting tube 102, and the bottom of the mounting block is fixedly connected to the top of the camera 6, through The mounting block realizes the connection between the camera 6 and the rectangular lower connecting tube 102. The camera 6 is used to monitor the situation inside the rectangular lower connecting tube 102. The right bottom of the rectangular lower connecting tube 102 is connected and fixed with a solenoid valve 5. The solenoid valve 5 is used for deflation and pressure reduction operation. The air pressure sensor 4, the solenoid valve 5, the two pressure sensors 12 and the synchronous control switch are all electrically connected to the PLC controller 8. The camera 6 and the air pressure sensor 4 are both electrically connected to the display screen 7. The camera 6 and the air pressure sensor 4 are both built-in with a signal sending module, and the display screen 7 is built-in with a display module and a signal receiving module. The signal sending module The module is connected to the signal receiving module, and the information detected by the camera 6 and the air pressure sensor 4 is released to the display screen 7 through the signal sending module and displayed on the display screen 7; the utility model can realize the stable pressure control seal between the rectangular upper connecting tube 101 and the rectangular lower connecting tube 102 through the setting of a series of structures, and can automatically increase the extrusion force for stable sealing when the reaction force is large and the sealing is reduced, thereby improving the stability of the pressure control seal and facilitating the personnel to accurately control the pressure value, so that the personnel can intuitively and clearly know the situation of the oil well operation equipment under different air pressures and improve the accuracy of the pressure test.

[0026] Working principle: When using, when conducting a pressure test on the oil well operation equipment, firstly, the two second electric telescopic rods 1 are controlled to open in the opposite direction synchronously through the synchronous control switch, and the output shafts of the two second electric telescopic rods 1 simultaneously drive the rectangular upper connecting tube 101 to move upward through the two moving blocks 2, and the rectangular upper connecting tube 101 drives the guide block 13 to move upward, and the rectangular upper connecting tube 101 drives the rectangular elastic sealing ring 9 to separate upward from the rectangular lower connecting tube 102, and the shielding of the rectangular lower connecting tube 102 is released, and the equipment to be tested can be placed under the rectangular The two second electric telescopic rods 1 are then controlled to open forward, so that the rectangular upper connecting tube 101 drives the rectangular elastic sealing ring 9 to move downward until it is in close contact with the top of the rectangular lower connecting tube 102. When the rectangular elastic sealing ring 9 moves downward, it also drives the first round frame 11 to move downward. The first round frame 11 drives the two pressure sensors 12 to move downward until they are in contact with the top of the second round frame 10. At this time, the first round frame 11 is restricted and cannot continue to move downward. At this time, the rectangular upper connecting tube 101 that continues to move downward contacts the rectangular elastic sealing ring 9. The sealing ring 9 is squeezed, and under the elastic force of the rectangular elastic sealing ring 9, the rectangular elastic sealing ring 9 is deformed, and provides a distance for the rectangular upper connecting tube 101 to continue to move downward. The rectangular upper connecting tube 101 that continues to move downward drives the four guide blocks 13 to slide downward on the corresponding L-shaped guide rods 14 and compress the compression spring 15. The guide blocks 13 generate a downward squeezing force on the first circular frame 11 through the compression spring 15. The first circular frame 11 drives the two pressure sensors 12 to squeeze the second circular frame 10. The pressure sensor 1 2 detects the extrusion pressure and transmits the detected pressure value to the PLC controller 8. When it is detected that the pressure value reaches the preset value, the PLC controller 8 controls the two second electric telescopic rods 1 to close through the synchronous control switch. At this time, the bottom of the rectangular elastic sealing ring 9 is in close contact with the top of the rectangular lower connecting tube 102, and the compression spring 15 in the compressed state will always give the rectangular elastic sealing ring 9 a downward tightening force through the first return frame 11, thereby realizing a stable pressure-controlled seal between the rectangular upper connecting tube 101 and the rectangular lower connecting tube 102;

[0027] During the pressure test, the first electric telescopic rod 3 is opened in the positive direction, and the output shaft of the first electric telescopic rod 3 drives the piston 104 to move downward. While the piston 104 moves downward, it squeezes the gas inside the rectangular upper connecting tube 101. Under the squeezing force, the gas pressure inside the rectangular upper connecting tube 101 and the rectangular lower connecting tube 102 increases, and the oil well operation equipment is tested by the gas pressure. With the increase of the gas pressure, the oil well operation equipment itself will change under the gas squeezing force. The camera 6 monitors the situation of the oil well operation equipment and transmits the monitored picture to the display screen 7 for display. At the same time, the pressure sensor 7 The sensor 4 detects the pressure value inside the rectangular lower connecting tube 102, and transmits the detected pressure value to the PLC controller 8 and the display screen 7. The display screen 7 displays the air pressure value, which is convenient for personnel to accurately control the pressure value, so that personnel can intuitively and clearly know the conditions of the oil well operation equipment under different air pressures, and improve the accuracy of the pressure test. When it is detected that the air pressure value exceeds the threshold, the PLC controller 8 controls the solenoid valve 5 to automatically open and control the first electric telescopic rod 3 to close, and the solenoid valve 5 releases gas to reduce the pressure, thereby achieving the purpose of automatically reducing the pressure when the air pressure value is large, reducing the safety hazards caused by the large air pressure value;

[0028] When the air pressure is high, there will be an upward reaction force. Since the rectangular upper connecting tube 101 is rigidly connected to the output shaft of the second electric telescopic rod 1, the rectangular upper connecting tube 101 will not move upward. Since the rectangular elastic sealing ring 9 is elastic, an upward squeezing force will be generated on the rectangular elastic sealing ring 9 under the reaction force, so that the bottom of the rectangular elastic sealing ring 9 moves upward, and the rectangular elastic sealing ring 9 drives the first circular frame 11 to move upward and compresses the compression spring 15 upward. The first circular frame 11 moves downward and drives the pressure sensor 12 to move upward, so that the squeezing force on the pressure sensor 12 is reduced. When the pressure sensor 12 detects that its squeezing force is reduced, it proves that the sealing between the rectangular elastic sealing ring 9 and the rectangular lower connecting tube 102 is reduced at this time. At this time, the PLC controller 8 controls the two second electric telescopic rods 1 to open forward again through the synchronous control switch, so that the rectangular upper connecting tube 101 continues to move downward to continue to squeeze the rectangular elastic sealing ring 9 downward. Under the squeezing force, the rectangular elastic sealing ring 9 is again in close contact with the top of the rectangular lower connecting tube 102, and the rectangular elastic sealing ring 9 drives the first circular frame 11 to move downward, and the first circular frame 11 drives the pressure sensor 12 to squeeze the second circular frame 10 downward. When it is detected that the squeezing force reaches the preset value, the two second electric telescopic rods 1 are controlled to close again, so as to achieve the effect of automatically increasing the squeezing force for sealing when the sealing performance is reduced, thereby improving the stability of the pressure-controlled seal and reducing the situation where the sealing connection is unstable due to the large reaction force.

[0029] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A special tool for testing pressure in oil wells, comprising a U-shaped seat (100), the top of which is fixedly connected to a mounting plate (103), a rectangular lower connecting tube (102) and a rectangular upper connecting tube (101) are arranged inside the U-shaped seat (100), the rectangular lower connecting tube (102) is fixedly connected to the bottom inner wall of the U-shaped seat (100), characterized in that: The sides of the rectangular lower connecting tube (102) and the rectangular upper connecting tube (101) that are close to each other are both set as openings. A rectangular elastic sealing ring (9) is bonded and fixed to the bottom of the rectangular upper connecting tube (101). The bottom of the rectangular elastic sealing ring (9) is in close contact with the top of the rectangular lower connecting tube (102). The outer side of the rectangular elastic sealing ring (9) and the outer side of the rectangular upper connecting tube (101) are fixedly connected with the same elastic tightening detection mechanism. The elastic tightening detection mechanism is fixedly sleeved on the rectangular lower connecting tube (102). Both sides of the rectangular upper connecting tube (101) are fixedly connected with vertical driving mechanisms. The mounting plate (103) is fixedly sleeved on the two vertical driving mechanisms. A piston (104) is provided in the sealing movable sleeve inside the rectangular upper connecting tube (101). The top of the connecting tube (101) is fixedly connected to a first electric telescopic rod (3) whose output shaft is fixedly connected to the top of the piston (104); the left side of the U-shaped seat (100) is fixedly connected to a display screen (7); the top of the display screen (7) is fixedly connected to a PLC controller (8); the left side of the rectangular lower connecting tube (102) is fixedly connected to an air pressure sensor (4); the right side of the rectangular lower connecting tube (102) is fixedly installed with an inclined camera (6); the right bottom of the rectangular lower connecting tube (102) is connected and fixed with an electromagnetic valve (5); the air pressure sensor (4), the electromagnetic valve (5), the elastic tension detection mechanism and the vertical drive mechanism are all electrically connected to the PLC controller (8); and the camera (6) and the air pressure sensor (4) are all electrically connected to the display screen (7).

2. A special tool for testing pressure in downhole petroleum operations according to claim 1, characterized in that: The elastic tension detection mechanism comprises a first circular frame (11) fixedly sleeved on a rectangular elastic sealing ring (9), a second circular frame (10) fixedly sleeved on a rectangular lower connecting tube (102), two guide blocks (13) fixedly connected to both sides of the rectangular upper connecting tube (101), two L-shaped guide rods (14) fixedly connected to both sides of the top of the first circular frame (11), the guide blocks (13) slidably sleeved on the corresponding L-shaped guide rods (14), a compression spring (15) in a compressed state fixedly connected between the bottom of the guide blocks (13) and the top of the first circular frame (11), the compression spring (15) movably sleeved on the corresponding L-shaped guide rods (14), pressure sensors (12) embedded and fixedly mounted on both sides of the bottom of the first circular frame (11), the bottom of the pressure sensor (12) being a detection end and movably contacting with the top of the second circular frame (10), and the two pressure sensors (12) being electrically connected to the PLC controller (8).

3. A special tool for testing pressure in downhole petroleum operations according to claim 2, characterized in that: The vertical drive mechanism comprises a moving block (2), the sides of the two moving blocks (2) close to each other are respectively fixedly connected to the tops of the two sides of the rectangular upper connecting tube (101), the bottom of the mounting plate (103) is embedded and fixed with two second electric telescopic rods (1), the bottom ends of the output shafts of the second electric telescopic rods (1) are fixedly connected to the tops of the corresponding moving blocks (2), the rear side of the left second electric telescopic rod (1) is fixedly connected with a synchronous control switch, and the synchronous control switch is electrically connected to the two second electric telescopic rods (1) and the PLC controller (8).

4. A special tool for testing pressure in downhole petroleum operations according to claim 1, characterized in that: The outer bonding sleeve of the piston (104) is provided with a sealing sleeve, and the outer side of the sealing sleeve is in active contact with the inner wall of the rectangular upper connecting cylinder (101).

5. A special tool for testing pressure in downhole petroleum operations according to claim 1, characterized in that: The top of the mounting plate (103) is provided with an avoidance hole with an opening at the front side, and the first electric telescopic rod (3) is located in the avoidance hole and does not contact the inner wall of the avoidance hole.

6. A special tool for testing pressure in oil wells according to claim 1, characterized in that: A mounting block is fixedly mounted on the right side of the rectangular lower connecting tube (102), the bottom of the mounting block is fixedly connected to the top of the camera (6), and the rectangular lower connecting tube (102) and the rectangular upper connecting tube (101) are both made of transparent materials.

7. A special tool for testing pressure in oil wells according to claim 1, characterized in that: The camera (6) and the air pressure sensor (4) are both equipped with a signal sending module, the display screen (7) is equipped with a display module and a signal receiving module, and the signal sending module is connected to the signal receiving module.

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