CN111980619A

CN111980619A - Oil pipe plug

Info

Publication number: CN111980619A
Application number: CN201910437850.0A
Authority: CN
Inventors: 张利平; 张建军; 张洪宝; 吕民; 陈磊; 陈大钊; 陈平; 宗伟; 徐路; 张鑫; 赵雅丽; 李宏远; 仲衡; 张建
Original assignee: Petrochina Co Ltd
Current assignee: Petrochina Co Ltd
Priority date: 2019-05-24
Filing date: 2019-05-24
Publication date: 2020-11-24
Anticipated expiration: 2039-05-24
Also published as: CN111980619B

Abstract

The invention discloses an oil pipe plug, which extends into a shaft along with an oil pipe, and comprises a central pipe, an expansion rubber cylinder, a slip component and a hydraulic cylinder, wherein the expansion rubber cylinder, the slip component and the hydraulic cylinder are all sleeved on the central pipe; the hydraulic cylinder comprises a hydraulic cylinder shell, a hydraulic cylinder stopper, a piston and a piston rod, wherein the hydraulic cylinder casing is sleeved on the central pipe, the hydraulic cylinder stopper can slide up and down and is arranged on the upper portion of the hydraulic cylinder casing, the inner wall of the upper portion of the hydraulic cylinder casing is tightly attached to the outer wall of the hydraulic cylinder stopper, a first cavity is formed between the bottom surface of the piston and the inner wall of the hydraulic cylinder casing, a first through hole communicated with the first cavity is formed in the side wall of the hydraulic cylinder casing, a second cavity is formed between the top of the piston and the inner wall of the hydraulic cylinder stopper, a second through hole and a third through hole are correspondingly formed in the central pipe and the piston rod, and the inside of the central pipe is communicated with the second cavity through hole and the third through hole. The invention solves the problems of poor sealing effect and complex operation and control of the oil pipe plug.

Description

Oil pipe plug

Technical Field

The invention relates to the technical field of well completion operation, in particular to an oil pipe plug.

Background

At present, before a tubular column is tripped out in conventional workover operation, the well needs to be snubbed in advance, and the tubular column in the well can be tripped out after the snubbing is stable. In order to save the workover cost, the workover operation at the present stage is to put a plug and an oil pipe into the well, and the plug is controlled to plug the shaft after being in place, so that the operation under pressure is carried out. Therefore, the sealing effect of the oil pipe plug on the shaft is the key of the whole operation failure under pressure, and the existing oil pipe plug generally has the defects of poor sealing effect, complex operation and the like.

Aiming at the problems of poor sealing effect and complex control of an oil pipe plug in the related art, an effective solution is not provided at present.

Therefore, the inventor provides the oil pipe plugging device by virtue of experience and practice of related industries for many years so as to overcome the defects in the prior art.

Disclosure of Invention

The invention aims to provide an oil pipe plug which can be stably plugged in an annular space between a shaft and an oil pipe, is simple and convenient to plug and disassemble and has high safety.

The purpose of the invention can be realized by adopting the following technical scheme:

the invention provides an oil pipe plug which is arranged at the bottom of an oil pipe and extends into a shaft along with the oil pipe, and the oil pipe plug comprises a central pipe, an expansion rubber cylinder for sealing an annular space between the oil pipe and the shaft, a slip assembly for fixing the central pipe in the shaft and a hydraulic cylinder for controlling the working state of the slip assembly, wherein the expansion rubber cylinder, the slip assembly and the hydraulic cylinder are sequentially sleeved on the central pipe from top to bottom, and the central pipe is connected with an external negative pressure device through the oil pipe;

The hydraulic cylinder comprises a hydraulic cylinder shell, a hydraulic cylinder stopper, a piston and a piston rod, the hydraulic cylinder stopper is sleeved on the central pipe and is positioned at the top of the hydraulic cylinder shell, the hydraulic cylinder stopper can be arranged at the upper part of the hydraulic cylinder shell in an up-and-down sliding manner, the inner wall of the upper part of the hydraulic cylinder shell is tightly attached to the outer wall of the hydraulic cylinder stopper, the bottom of the piston rod is connected with the top of the piston, the top of the piston rod is abutted against the bottom of the hydraulic cylinder stopper, the outer wall of the piston is tightly attached to the inner wall of the hydraulic cylinder shell, a first chamber is formed between the bottom surface of the piston and the inner wall of the hydraulic cylinder shell, a first through hole communicated with the first chamber is formed in the side wall of the hydraulic cylinder shell, and a second chamber is formed between the top of the piston, the bottom of the hydraulic cylinder stopper and the inner wall of the hydraulic cylinder shell, the central tube and the piston rod are correspondingly provided with a second through hole and a third through hole which are communicated, and the interior of the central tube is communicated with the second chamber through the second through hole and the third through hole.

In a preferred embodiment of the present invention, the second through holes are elongated through holes opened in a vertical direction, the number of the second through holes is plural, and the plural second through holes are uniformly distributed along a circumferential direction of the central tube.

In a preferred embodiment of the present invention, the number of the first through holes is plural, and the plural first through holes are uniformly arranged along the circumferential direction of the hydraulic cylinder casing.

In a preferred embodiment of the present invention, the slip assembly includes an upper slip, a slip seat and a lower slip which are sequentially sleeved outside the central tube from top to bottom, the slip seat is of a cone-shaped structure, a lower portion of the upper slip is sleeved on an upper portion of the slip seat in an up-and-down sliding manner, an upper portion of the lower slip is sleeved on a lower portion of the slip seat in an up-and-down sliding manner, a top of the upper slip presses a bottom of the expansion rubber cylinder, and a bottom of the lower slip presses a top of the hydraulic cylinder stopper.

In a preferred embodiment of the present invention, a plurality of first slots are annularly disposed on an outer wall of a lower portion of the upper slip, a plurality of second slots are annularly disposed on an outer wall of an upper portion of the lower slip, and when the upper slip moves downward, the plurality of first slots are tightly engaged with an inner wall of the wellbore; when the lower slip moves upwards, the second clamping grooves are matched and clamped with the inner wall of the shaft.

In a preferred embodiment of the present invention, each of the first and second slots has a saw-toothed structure that is continuously arranged in a vertical direction at intervals.

In a preferred embodiment of the present invention, a first receiving chamber is formed inside the upper slip, a second receiving chamber is formed inside the lower slip, and when the upper slip moves downward, the top of the upper slip extends into the first receiving chamber; when the lower slip moves upwards, the bottom of the lower slip extends into the second accommodating cavity.

In a preferred embodiment of the present invention, the top and the bottom of the expansion rubber cylinder are respectively provided with a rubber cylinder shield.

In a preferred embodiment of the present invention, an upper joint is disposed above the central pipe, the upper joint is a cylindrical structure disposed along a vertical direction, a top of the upper joint is connected to a bottom of the oil pipe, and a bottom of the upper joint is connected to a top of the central pipe through a connecting member.

In a preferred embodiment of the present invention, the upper joint is screwed to the bottom of the oil pipe, the connecting member is an annular structure, the bottom of the upper joint is fixedly connected to the upper portion of the connecting member by a plurality of shear pins, and the lower portion of the connecting member is screwed to the top of the central pipe.

In a preferred embodiment of the present invention, the liquid cylinder stopper is a cylindrical structure with a top seal and a bottom opening.

In a preferred embodiment of the invention, a guide head is arranged below the hydraulic cylinder, and the top of the guide head is in threaded connection with the bottom of the central tube.

In a preferred embodiment of the present invention, the guide head is an inverted cone structure.

From the above, the oil pipe plug of the invention has the characteristics and advantages that: the outer side of a central tube of the oil tube plug is sequentially sleeved with an expansion rubber cylinder, a slip assembly and a hydraulic cylinder from top to bottom, wherein the hydraulic cylinder comprises a hydraulic cylinder shell, a hydraulic cylinder stopper, a piston and a piston rod, the hydraulic cylinder stopper can be arranged on the upper portion of the hydraulic cylinder shell in an up-and-down sliding manner, the piston and the piston rod are positioned in the hydraulic cylinder shell, a first cavity is formed between the bottom surface of the piston and the inner wall of the hydraulic cylinder shell, a first through hole communicated with the first cavity is formed in the side wall of the hydraulic cylinder shell, a second cavity is formed between the top of the piston, the bottom of the hydraulic cylinder stopper and the inner wall of the hydraulic cylinder shell, the second cavity is communicated with the inside of the central tube through a second through hole in the central tube and a third through hole in the piston rod, through reducing the pressure in the central tube, gas outside the oil tube plug enters the first cavity through the first through hole and pushes the piston to move upwards, and further pushes the upper slip, the slip seat jacks the lower part of the upper slip and the upper part of the lower slip and firmly clamps the inner wall of the shaft, so that the oil pipe plug is stably fixed in the shaft, and in addition, the expansion rubber cylinder is extruded by upward movement of the upper slip, so that the expansion rubber cylinder expands outwards to realize a good sealing effect on the shaft; through recovering the atmospheric pressure in the center tube, gas in the center tube passes through in second through-hole and the third through-hole entering second cavity, and then promote the piston and reset, go up the slips, lower slips and inflation packing element resume original position and with the inner wall separation of pit shaft, can take out the oil pipe blanking plug, only need the intraductal atmospheric pressure of control center can accomplish shutoff and the mediation to the pit shaft, not only have good sealed effect to the pit shaft, and it is simple and convenient to control moreover, the security is high, be applicable to and use widely in the workover.

Drawings

The drawings are only for purposes of illustrating and explaining the present invention and are not to be construed as limiting the scope of the present invention. Wherein:

FIG. 1: is a structural schematic diagram of the tubing plug of the present invention.

Reference numerals in the present invention: 1. a central tube; 101. a second through hole; 2. expanding the rubber cylinder; 3. a slip assembly; 301. the slips are put on; 3011. a first card slot; 3012. a first accommodating cavity; 302. a slip is put down; 3021. a second card slot; 3022. a second accommodating cavity; 303. a slip seat; 4. a hydraulic cylinder; 401. a hydraulic cylinder housing; 402. a second chamber; 403. a first chamber; 404. a first through hole; 5. a piston; 6. an upper joint; 7. a hydraulic cylinder stopper; 8. a connecting member; 9. a rubber cylinder shield; 10. shearing the pin; 11. a guide head; 12. a piston rod; 1201. a third via.

Detailed Description

In order to more clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will now be described with reference to the accompanying drawings.

As shown in fig. 1, the present invention provides a tubing plug, which is disposed at the bottom of a tubing and extends into a wellbore along with the tubing, and comprises a central tube 1, an expansion rubber sleeve 2, a slip assembly 3 and a hydraulic cylinder 4, wherein the expansion rubber sleeve 2 is used for sealing an annular space between the tubing and the wellbore, the slip assembly 3 is used for fixing the central tube 1 in the wellbore and plugging the annular space between the wellbore and the tubing, and the hydraulic cylinder 4 is used for controlling the working state of the slip assembly 3. The central tube 1 is a cylindrical structure arranged along the vertical direction, the expansion rubber tube 2, the slip component 3 and the hydraulic cylinder 4 are sequentially sleeved on the outer side of the central tube 1 from top to bottom, and the central tube 1 is connected with an external negative pressure device through an oil tube.

As shown in fig. 1, the hydraulic cylinder 4 includes a hydraulic cylinder housing 401, a hydraulic cylinder stopper 7, a piston 5 and a piston rod 12, the hydraulic cylinder housing 401, the hydraulic cylinder stopper 7, the piston 5 and the piston rod 12 are all sleeved on the central tube 1, and the hydraulic cylinder stopper 7, the piston 5 and the piston rod 12 can slide up and down along the central tube 1, the hydraulic cylinder stopper 7 is a cylindrical structure with a sealed top and an open bottom, the hydraulic cylinder stopper 7 is located at the top of the hydraulic cylinder housing 401, the hydraulic cylinder stopper 7 can be arranged at the upper part of the hydraulic cylinder housing 401 in an up-and-down sliding manner, the inner wall of the upper part of the hydraulic cylinder housing 401 is tightly attached to the outer wall of the hydraulic cylinder stopper 7, the piston rod 12 and the piston 5 are both located inside the hydraulic cylinder housing 401, the bottom of the piston rod 12 is connected to the top of the piston 5, the top of the piston rod 12 abuts against the bottom of the hydraulic cylinder stopper 7, the outer wall of the piston 5 is tightly attached to the inner wall of the hydraulic cylinder housing 401, a first through hole 404 communicated with the first chamber 403 is formed in the side wall of the hydraulic cylinder shell 401, a circular second chamber 402 is formed between the top of the piston 5, the bottom of the hydraulic cylinder stopper 7 and the inner wall of the hydraulic cylinder shell 401, a second through hole 101 is formed in the side wall of the center tube 1, a third through hole 1201 is formed in the position, corresponding to the second through hole 101, of the side wall of the piston rod 12, the second through hole 101 is communicated with the third through hole 1201, and the inside of the center tube 1 is communicated with the second chamber 402 through the second through hole 101 and the third through hole 1201. According to the invention, the air pressure in the central tube 1 is reduced through the negative pressure device, so that the air outside the oil tube plug enters the first chamber 403 through the first through hole 404 and pushes the piston 5 to move upwards, and then the slip component 3 is pushed to act through the hydraulic cylinder stopper 7, the outer wall of the slip component 3 is firmly clamped on the inner wall of the shaft, the oil tube plug is ensured to be stably fixed in the shaft, and in addition, the slip component 3 moves upwards to extrude the expansion rubber cylinder 2, so that the expansion rubber cylinder 2 expands outwards to realize a good sealing effect on the shaft; through recovering atmospheric pressure in the center tube 1, gas in the center tube 1 gets into in the second chamber 402 through second through-hole 101 and third through-hole 1201, and then promote piston 5 and reset, slips subassembly 3 and inflation packing element 2 resume primary importance and with the inner wall separation of pit shaft, can take out the oil pipe blanking plug, whole process only needs the atmospheric pressure in the control center tube 1 can accomplish shutoff and the mediation to the pit shaft, not only have good sealed effect to the pit shaft, and it is simple and convenient to control moreover, high safety, be applicable to and use widely in workover.

Further, the oil pipe can be, but is not limited to, a small oil pipe or a coiled oil pipe.

Further, as shown in fig. 1, the second through holes 101 are elongated through holes opened in the vertical direction, the number of the second through holes 101 is plural, and the plural second through holes 101 are uniformly arranged along the circumferential direction of the central tube 1.

Further, as shown in fig. 1, the number of the first through holes 404 is plural, the plural first through holes 404 are uniformly arranged along the circumferential direction of the cylinder case 401, and the position of each first through hole 404 is opposite to the position of the corresponding second through hole 101.

Specifically, the number of the second through holes 101 and the number of the first through holes 404 are four.

As shown in fig. 1, the slip assembly 3 includes an upper slip 301, a slip seat 303 and a lower slip 302 which are sequentially sleeved outside the central tube 1 from top to bottom, the upper slip 301, the slip seat 303 and the lower slip 302 can move up and down along the central tube 1, the slip seat 303 is of a cone-shaped structure, the lower part of the upper slip 301 can be sleeved on the upper part of the slip seat 303 in an up-and-down sliding manner, the upper part of the lower slip 302 can be sleeved on the lower part of the slip seat 303 in an up-and-down sliding manner, the top of the upper slip 301 presses the bottom of the expansion rubber cylinder 2, and the bottom of the lower slip 302 presses the top of the hydraulic cylinder stopper 7. A plurality of first clamping grooves 3011 are annularly arranged on the outer wall of the lower part of the upper slip 301, a plurality of second clamping grooves 3021 are annularly arranged on the outer wall of the upper part of the lower slip 302, and when the lower slip 302 moves upwards, the plurality of second clamping grooves 3021 are matched and clamped with the inner wall of the shaft; when the lower slip 302 and the slip seat 303 push the upper slip 301 to move upwards, the plurality of first clamping grooves 3011 are matched and clamped with the inner wall of the well bore. The upper slip 301 and the lower slip 302 can be pushed to move simultaneously through the piston 5, and the upper slip 301 and the lower slip 302 are matched and clamped with the inner wall of the shaft, so that the stability of the tubing plug for plugging the shaft is greatly improved.

Specifically, the spinning cone structure of the slip bowl 303 is a cylinder with a diameter gradually decreasing from the middle to the top and the bottom.

As shown in fig. 1, each of the first card slots 3011 and the second card slots 3021 has a zigzag structure continuously arranged at intervals in the vertical direction.

As shown in fig. 1, an annular first accommodating cavity 3012 is formed inside the upper slip 301, an annular second accommodating cavity 3022 is formed inside the lower slip 302, and when the lower slip 302 moves upwards, the bottom of the lower slip 302 extends into the second accommodating cavity 3022; when the lower slip 302 and the slip bowl 303 push the upper slip 301 upwards, the top of the upper slip 301 extends into the first receiving cavity 3012.

As shown in fig. 1, an upper joint 6 is arranged above the central pipe 1, the upper joint 6 is a cylindrical structure arranged along the vertical direction, the top of the upper joint 6 is connected with the bottom of the oil pipe, and the bottom of the upper joint 6 is connected with the top of the central pipe 1 through a connecting piece 8.

Specifically, the top of top connection 6 is connected with the bottom screw thread of oil pipe, and connecting piece 8 is the ring form structure, and a plurality of shear pin 10 fixed connection are passed through to the bottom of top connection 6 and the upper portion of connecting piece 8, and shear pin 10 passes the diapire lateral wall of top connection 6 and the upper portion lateral wall of connecting piece 8, and the lower part of connecting piece 8 is connected with the top screw thread of center tube 1.

Further, as shown in fig. 1, a rubber cylinder protective cover 9 is respectively arranged at the top and the bottom of the expansion rubber cylinder 2, the rubber cylinder protective cover 9 is of a circular ring structure, the rubber cylinder protective cover 9 located at the top of the expansion rubber cylinder 2 isolates the expansion rubber cylinder 2 from the connecting piece 8, and the rubber cylinder protective cover 9 located at the bottom of the expansion rubber cylinder 2 isolates the expansion rubber cylinder 2 from the upper slip 301, so that the expansion rubber cylinder 2 is protected.

As shown in fig. 1, a guide head 11 is arranged below the hydraulic cylinder 4, the guide head 11 is in an inverted cone-shaped structure, the top of the guide head 11 is in threaded connection with the bottom of the central tube 1, and the guide head 11 ensures that the tubing plug can smoothly extend into a preset position in a wellbore.

In the using process of the oil pipe plug, after an upper joint 6 of the oil pipe plug is connected to the bottom of an oil pipe and is lowered into a well bore along with the oil pipe to a preset position, gas in a central pipe 1 is extracted through a negative pressure device, so that the gas pressure in the central pipe 1 is smaller than the gas pressure in the well bore below the central pipe 1, the gas in the well bore enters a first chamber 403 through a first through hole 404 and pushes a piston 5 to move upwards, an upper slip 301 and a lower slip 302 are pushed to move towards the middle part relative to a slip seat 303 through a hydraulic cylinder stopper 7, the inner wall of the lower part of the upper slip 301 and the inner wall of the upper part of the lower slip 302 are tightly pressed by the slip seat 303, the outer wall of the lower part of the upper slip 301 and the outer wall of the upper part of the lower slip 302 expand outwards, so that the outer wall of the lower part of the upper slip 301 and the outer wall of the upper slip 302 are firmly clamped on the inner, the expansion rubber sleeve 2 expands outwards to complete the blocking of the annulus between the shaft and the oil pipe; after the well repairing work is finished, the air pressure in the central pipe 1 is recovered, the air in the central pipe 1 enters the second chamber 402 through the second through hole 101 and the third through hole 1201, the piston 5 is further pushed to reset, the upper slip 301, the lower slip 302 and the expansion rubber cylinder 2 recover the original positions and are separated from the inner wall of the shaft, the shearing pin 10 is cut off after the oil pipe is lifted, the oil pipe is lifted to the ground, and the oil pipe blanking plug falls to the bottom of the well, so that the deblocking is finished.

The oil pipe blanking plug has the characteristics and advantages that:

firstly, reducing the air pressure in the central tube 1 through a negative pressure device, enabling the air outside the oil tube plug to enter a first chamber 403 through a first through hole 404 and push a piston 5 to move upwards, further pushing an upper slip 301 and a lower slip 302 to move towards the middle of a slip seat 303 through a hydraulic cylinder stopper 7, clamping the inner wall of the shaft through the upper slip 301 and the lower slip 302, ensuring that the oil tube plug is stably fixed in the shaft, and in addition, extruding an expansion rubber cylinder 2 through the upward movement of the upper slip 301, so that the expansion rubber cylinder 2 expands outwards to realize a good sealing effect on the shaft; through recovering the atmospheric pressure in the center tube 1, go up slips 301, slips 302 and expansion rubber sleeve 2 and resume primary importance and with the inner wall separation of pit shaft, can take out the oil pipe blanking plug, whole process only needs the atmospheric pressure in the control center tube 1 can accomplish shutoff and the mediation to the pit shaft, not only has good sealed effect to the pit shaft, controls portably moreover, the security is high, is applicable to and uses widely in the workover.

When an annular space between the shaft and the oil pipe is plugged, the upper slip 301 and the lower slip 302 are simultaneously matched and clamped with the inner wall of the shaft, the plugging position is accurate, and the stability of the oil pipe plugging device for plugging the shaft is greatly improved.

The above description is only an exemplary embodiment of the present invention, and is not intended to limit the scope of the present invention. Any equivalent changes and modifications that can be made by one skilled in the art without departing from the spirit and principles of the invention should fall within the protection scope of the invention.

Claims

1. An oil pipe plug is arranged at the bottom of an oil pipe and extends into a shaft along with the oil pipe, and is characterized by comprising a central pipe (1), an expansion rubber sleeve (2) for sealing an annular space between the oil pipe and the shaft, a slip assembly (3) for fixing the central pipe (1) in the shaft and a hydraulic cylinder (4) for controlling the working state of the slip assembly (3), wherein the expansion rubber sleeve (2), the slip assembly (3) and the hydraulic cylinder (4) are sequentially sleeved on the central pipe (1) from top to bottom, and the central pipe (1) is connected with an external negative pressure device through the oil pipe;

the hydraulic cylinder (4) comprises a hydraulic cylinder shell (401) sleeved on the central pipe (1), a hydraulic cylinder stopper (7), a piston (5) and a piston rod (12), the hydraulic cylinder stopper (7) is located at the top of the hydraulic cylinder shell (401), the hydraulic cylinder stopper (7) can be arranged at the upper part of the hydraulic cylinder shell (401) in an up-and-down sliding manner, the inner wall of the upper part of the hydraulic cylinder shell (401) is tightly attached to the outer wall of the hydraulic cylinder stopper (7), the bottom of the piston rod (12) is connected with the top of the piston (5), the top of the piston rod (12) is abutted to the bottom of the hydraulic cylinder stopper (7), the outer wall of the piston (5) is tightly attached to the inner wall of the hydraulic cylinder shell (401), a first chamber (403) is formed between the bottom surface of the piston (5) and the inner wall of the hydraulic cylinder shell (401), and a first through hole (403) communicated with the first chamber (403) is formed in the side wall of the hydraulic cylinder shell (401) 404) A second chamber (402) is formed between the top of the piston (5), the bottom of the hydraulic cylinder stopper (7) and the inner wall of the hydraulic cylinder shell (401), a second through hole (101) and a third through hole (1201) which are communicated with each other are correspondingly formed in the central tube (1) and the piston rod (12), and the inside of the central tube (1) is communicated with the second chamber (402) through the second through hole (101) and the third through hole (1201).

2. The tubing plug as claimed in claim 1, wherein the second through holes (101) are elongated through holes opened in a vertical direction, the number of the second through holes (101) is plural, and the plural second through holes (101) are uniformly distributed along the circumferential direction of the central tube (1).

3. The tubing plug as claimed in claim 1, wherein the first through holes (404) are plural in number, and the plural first through holes (404) are uniformly arranged in a circumferential direction of the cylinder case (401).

4. The tubing plug as claimed in claim 1, wherein the slip assembly (3) comprises an upper slip (301), a slip seat (303) and a lower slip (302) which are sequentially sleeved on the outer side of the central tube (1) from top to bottom, the slip seat (303) is of a cone-shaped structure, the lower part of the upper slip (301) is sleeved on the upper part of the slip seat (303) in an up-and-down sliding manner, the upper part of the lower slip (302) is sleeved on the lower part of the slip seat (303) in an up-and-down sliding manner, the top of the upper slip (301) presses the bottom of the expansion rubber cylinder (2), and the bottom of the lower slip (302) presses the top of the hydraulic cylinder stopper (7).

5. The tubing plug as claimed in claim 4, wherein a plurality of first slots (3011) are arranged on the outer wall of the lower part of the upper slip (301), a plurality of second slots (3021) are arranged on the outer wall of the upper part of the lower slip (302), and when the upper slip (301) moves downwards, the first slots (3011) are matched with the inner wall of the shaft to be clamped; when the lower slip (302) moves upwards, the second clamping grooves (3021) are matched and clamped with the inner wall of the shaft.

6. The tubing plug as claimed in claim 5, wherein the first slots (3011) and the second slots (3021) are all sawtooth structures continuously arranged at intervals in the vertical direction.

7. The tubing plug as claimed in claim 4, wherein a first accommodating cavity (3012) is formed inside the upper slip (301), a second accommodating cavity (3022) is formed inside the lower slip (302), and when the upper slip (301) moves downwards, the top of the upper slip (301) extends into the first accommodating cavity (3012); when the lower slip (302) moves upwards, the bottom of the lower slip (302) extends into the second accommodating cavity (3022).

8. Tubing plug according to claim 1, characterized in that the top and bottom of the expanding rubber sleeve (2) are provided with rubber sleeve shields (9), respectively.

9. Tubing plug according to claim 1, characterized in that an upper joint (6) is arranged above the central tube (1), the upper joint (6) is a cylindrical structure arranged along the vertical direction, the top of the upper joint (6) is connected with the bottom of the tubing, and the bottom of the upper joint (6) is connected with the top of the central tube (1) through a connecting piece (8).

10. Tubing plug according to claim 9, characterized in that the upper joint (6) is threaded to the bottom of the tubing, the connecting member (8) is a ring-shaped structure, the bottom of the upper joint (6) is fixedly connected to the upper part of the connecting member (8) by a plurality of shear pins (10), and the lower part of the connecting member (8) is threaded to the top of the central tube (1).

11. Tubing plug according to claim 1, characterized in that said hydraulic cylinder stopper (7) is a top-closed, bottom-open tubular structure.

12. Tubing plug according to claim 1, characterized in that a guiding head (11) is arranged below the hydraulic cylinder (4), and the top of the guiding head (11) is screwed with the bottom of the central tube (1).

13. Tubing plug according to claim 12, characterized in that said guiding head (11) is of inverted cone-shaped construction.