CN115126454A

CN115126454A - Oil pipe plug

Info

Publication number: CN115126454A
Application number: CN202110312315.XA
Authority: CN
Inventors: 宋显民
Original assignee: Petrochina Co Ltd
Current assignee: Petrochina Co Ltd
Priority date: 2021-03-24
Filing date: 2021-03-24
Publication date: 2022-09-30
Anticipated expiration: 2041-03-24
Also published as: CN115126454B

Abstract

The embodiment of the application discloses an oil pipe plug belongs to oil field separate zone water injection technical field. The oil pipe plug comprises a delivery device, a sealing device, a locking device and an unsealing device. Wherein, one end of the sealing device is connected with the delivery device, and the other end of the sealing device is connected with the locking device; the decapsulation unit is located in the cavity of the sealing device. The tubing plug is delivered into a working barrel of the underground pipe column through a delivery device of a delivery and fishing tool, and the position of the tubing plug is locked through a locking device. The throwing and fishing tool is lifted to separate the throwing and fishing device from the oil pipe plug, and the liquid with pressure in the well enters the sealing device to complete sealing in the separation process. The sealing part of the tubing plug utilizes downhole fluid to provide sealing pressure, and the sealing performance is enhanced along with the increase of the downhole pressure. When the oil pipe plug is recovered, the unsealing device is unsealed and locked by lifting the throwing and fishing tool, so that the recovery and repeated investment of the oil pipe plug are realized.

Description

Oil pipe plug

Technical Field

The application relates to the technical field of oilfield separate-layer water injection, in particular to an oil pipe plug.

Background

The oil field water injection well adopts the area to press the operation construction mostly, and the purpose is not put the pressure before guaranteeing the operation construction, avoids shortening the water injection time of water injection well because of putting the pressure, also avoids simultaneously that the water that has injected into the stratum returns out ground because of putting the pressure and causes the waste. In order to ensure the smooth operation of lifting and lowering the tubular column under pressure, an oil pipe plug is required to be put into the water injection tubular column before construction, and the oil pipe plug forms internal seal with the inner wall of a working barrel in the bottom of the water injection tubular column so that high-pressure liquid in the stratum does not flow into the water injection tubular column. Meanwhile, a sealing device is adopted at the wellhead to seal the annular space between the oil pipe and the casing pipe, so that the oil pipe can be lifted and lowered without returning liquid in the well.

The tubing plug in the related art realizes locking by biting a supporting slip into the inner wall of a working barrel or an oil pipe, and seals the working barrel or the oil pipe through a self-sealing or compression rubber sleeve. In the oil pipe plug in the related art, the diameter of the compression rubber cylinder is increased by the pressure along the axial direction of the oil pipe plug, and the sealing of the working cylinder or the inner wall of the oil pipe is completed.

In the implementation process of the invention, the inventor finds that the related art has at least the following problems:

in the related art, the oil pipe plug adopts slips to bite into the inner wall of a working barrel or an oil pipe, the inner wall of the working barrel or the oil pipe is sealed by a self-sealing or compression rubber cylinder, and the sealing performance of the sealing mode is reduced along with the rise of the formation pressure; the oil pipe plug in the related art is a permanent device, and has limitation in recycling and reuse after being put into use; the oil pipe blanking plug in the related art is easy to move up and down before sealing is finished, so that the sealing position is inaccurate.

Disclosure of Invention

The embodiment of the application provides an oil pipe plug to solve the problems that in the related art, the sealing performance of the oil pipe plug is lowered along with the increase of the pressure of a place, and the problems of limitation and inaccurate sealing position exist in recycling and reuse. The technical scheme is as follows:

the embodiment of the application provides an oil pipe plug, which comprises a delivery device, a sealing device, a locking device and an unsealing device;

wherein one end of the delivering device is connected with the delivering and fishing tool; the other end of the delivery device is connected with one end of the sealing device, and the other end of the sealing device is connected with the locking device; the unsealing device is positioned in the cavity of the sealing device;

the delivery device is used for delivering the oil pipe plug into a working barrel at a reference position in the underground oil pipe; the sealing device is used for sealing a gap between the working barrel and the tubing plug through the pressure of downhole liquid; the locking device is used for locking the oil pipe plug in the working barrel and preventing the oil pipe plug from moving up and down before sealing is finished; the sealing device is used for releasing the sealing of the working barrel by the sealing device and releasing the locking of the locking device on the position of the oil pipe plug when the oil pipe plug is recovered, so that the oil pipe plug can be recovered for repeated delivery.

Optionally, the delivery device comprises a rope head, a delivery barrel, a first shear pin group and a second shear pin group;

one end of the rope head is connected with the wellhead delivery equipment, and the other end of the rope head is connected with one end of the delivery cylinder; the other end of the delivery cylinder is connected with the sealing device; the other end of the delivery barrel is sequentially provided with the first shear pin group and the second shear pin group;

the first shear pin group is a group of shear pins symmetrically distributed along the axis of the delivery cylinder;

the second shear pin group is a group of shear pins symmetrically distributed along the axis of the delivery cylinder.

Optionally, the sealing device includes a sealing pull cylinder, an upper pressure cap, an upper connection sleeve, an upper main body, a rubber cylinder, a lower connection sleeve, a lower pressure cap, a sealing ring, a first bolt group and a second bolt group;

one end of the sealing pull cylinder is arranged in the cavity of the upper main body, and the other end of the sealing pull cylinder is exposed out of the upper main body; the rubber sleeve is sleeved outside the upper main body; the upper connecting sleeve and the lower connecting sleeve are positioned on the outer wall of the upper main body; the upper pressing cap is positioned at one end of the rubber cylinder, and the lower pressing cap is positioned at the other end of the rubber cylinder; the upper pressure cap is connected with the rubber cylinder through the upper connecting sleeve; the lower pressing cap is connected with the rubber cylinder through the lower connecting sleeve; at least two groups of sealing rings are sleeved on the outer wall of the sealing pull cylinder; the first bolt group and the second bolt group are positioned at one end of the sealing pull cylinder, which is exposed out of the upper main body; the first shear pin group is located between the first bolt group and the second bolt group; one end of the upper pressing cap close to the delivery device is provided with a boss protruding in the radial direction; the upper main body is connected with the delivery barrel through the second shear pin group.

Optionally, the locking portion comprises a lower body, a shaft, a cam, and a torsion spring;

wherein at least one group of the sealing rings is sleeved on the lower main body; the top end of the lower main body is connected with the upper main body; the shaft is mounted within the lower body; the cam is mounted on the shaft; the torsion spring is sleeved on the shaft; the torsion spring is connected with the cam, and the cam is in a radial opening state through the elasticity of the torsion spring.

Optionally, the deblocking part comprises an upper pull rod, a lower pull rod and a third shear nail group;

the upper pull rod axially penetrates through an inner cavity of the sealing pull cylinder, the top end of the upper pull rod is positioned outside the sealing pull cylinder, and the bottom end of the upper pull rod is positioned inside the upper main body; the top end of the lower pull rod is connected with the bottom end of the upper pull rod; the bottom end of the lower pull rod is connected with the lower main body through the third shear pin group.

Optionally, the outer diameters of the top end and the middle part of the sealing pull cylinder are smaller than the outer diameter of the bottom end of the sealing pull cylinder, so that a bottom boss is formed.

Optionally, a pressure relief hole is formed in the barrel body on the upper edge of the boss at the bottom of the sealing pull cylinder.

Optionally, the lower main body is a cylinder with a conical bottom, a group of through holes are formed in the upper part of the cylinder, and a blind hole is formed in the lower end of the cylinder; a through groove with a rectangular cross section is arranged on the side wall of the lower part of the lower main body, and a group of round through holes are upwards arranged in the through groove method;

the group of through holes arranged at the upper part of the cylinder body are used for installing the third shear pin group; the blind hole arranged at the lower end of the cylinder body is used for connecting the torsion spring; the through groove with the rectangular cross section is used for providing a space for the cam to contract or expand and providing a channel for downhole liquid to enter the tubing plug; the set of circular through holes is used for mounting the shaft.

Optionally, one end of the torsion spring is pressed inside the long claw of the cam, and the other end of the torsion spring is inserted into the blind hole at the lower end of the lower body.

Optionally, the top end of the upper pull rod is a conical step, and the bottom end of the upper pull rod is provided with an external thread; the top end of the lower pull rod is provided with an axial non-through hole, and the inner wall of the axial non-through hole is provided with internal threads; the bottom end of the upper pull rod is connected with the top end of the lower pull rod through threads.

The beneficial effects brought by the technical scheme provided by the embodiment of the application at least comprise:

the oil pipe blanking plug provided by the embodiment of the application is sent into the working barrel of the reference position of the underground pipe column through the steel wire connection delivery device. When the oil pipe plug reaches the reference position, the position of the oil pipe plug is locked through the locking device, and the oil pipe plug is prevented from moving up and down. The sealing device of the oil pipe plug seals a gap between the working barrel and the oil pipe plug by utilizing the pressure of downhole liquid, and the sealing performance is enhanced along with the increase of the formation pressure. The oil pipe plug can be unlocked and sealed by using the deblocking device, so that the oil pipe plug can be recovered and repeatedly put into use.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a cross-sectional view A-A of one configuration of a tubing plug according to an embodiment of the present application.

The reference numerals in the drawings denote:

1-a delivery device;

11-rope end;

12-a delivery cylinder;

13-a first set of staples;

14-a second group of staples;

2-sealing device;

21-sealing the pull cylinder;

22-pressing the cap upwards;

23-upper connecting sleeve;

24-an upper body;

25-a rubber cylinder;

26-lower connecting sleeve;

27-pressing down the cap;

28-sealing ring;

29 — a first bolt set;

210 — a second bolt set;

3-a locking device;

31 — a lower body;

32-axis;

33-a cam;

34-a torsion spring;

4-unsealing the device;

41-upper pull rod;

42-lower tie rod;

43-third shear set.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

The embodiment of the application provides a tubing plug, which comprises a delivery device 1, a sealing device 2, a locking device 3 and an unsealing device 4, as shown in fig. 1.

Wherein, one end of the throwing device 1 is connected with a throwing and fishing tool; the other end of the delivery device 1 is connected with one end of the sealing device 2; the unsealing device 4 is positioned in the cavity of the sealing device 2; the locking device 3 is connected to the other end of the sealing device 2.

The delivery device 1 is connected with a delivery tool and is used for delivering the oil pipe blanking plug into a working barrel at a reference position in the underground oil pipe; one end of the sealing device 2 is connected with the delivery device 1, and the sealing device 2 is used for sealing a gap between the working barrel and the oil pipe plug by adopting the pressure of downhole liquid; the locking device 3 is used for locking the oil pipe plug in the working barrel and preventing the oil pipe plug from moving up and down. The unsealing device 4 is used for unsealing the working barrel by the sealing device 2 and unlocking the position of the tubing plug by the locking device 3 when the tubing plug is recovered, so that the tubing plug is recovered for repeated delivery.

Illustratively, the running and fishing tool is a steel wire, an oil pipe or a drill pipe.

In an alternative embodiment, as shown in fig. 1, the delivery device 1 of the tubing plug provided in the embodiment of the present application includes a string head 11, a delivery barrel 12, a first shear pin set 13, and a second shear pin set 14.

Wherein, one end of the rope head 11 is connected with a throwing and fishing tool; the other end of the rope end 11 is connected with one end of the delivery cylinder 12; the other end of the delivery cylinder 12 is connected to the sealing device 2. The other end of the delivery barrel 12 is provided with a first shear pin group 13 and a second shear pin group 14 in sequence. The first shear pin group 13 is a group of shear pins symmetrically distributed along the axis of the delivery cylinder 12; the second group of staples 14 is a group of staples symmetrically distributed along the axis of the delivery barrel 12.

The rope end 11 is used for connecting a throwing and fishing tool; the delivery cylinder 12 is used for connecting the rope end 11 and the sealing pull cylinder 21; the first shear pin 13 is used for driving the first bolt 29 to move towards the direction close to the rope end 11; the second staple set 14 is used to connect the delivery cartridge 12 and the upper body 24 of the sealing device 2. Illustratively, the rope end 11 is a conical cap, and the tip of the conical device of the rope end 11 is provided with a through hole.

In an alternative embodiment, as shown in fig. 1, the sealing device 2 of the tubing plug provided in the embodiment of the present application includes a sealing pull cylinder 21, an upper press cap 22, an upper connection sleeve 23, an upper main body 24, a rubber cylinder 25, a lower connection sleeve 26, a lower press cap 27, a sealing ring 28, a first bolt group 29, and a second bolt group 210.

One end of the sealing pull cylinder 21 is arranged in the cavity of the upper main body 24, and the other end of the sealing pull cylinder 21 is exposed out of the upper main body 24; the rubber cylinder 25 is sleeved outside the upper main body 24; the upper connecting sleeve 23 and the lower connecting sleeve 26 are positioned on the outer wall of the upper main body 24; the upper pressing cap 22 is positioned at one end of the rubber cylinder 25, and the lower pressing cap 27 is positioned at the other end of the rubber cylinder 25; the upper pressure cap 22 is connected with the rubber cylinder 25 through an upper connecting sleeve 23; the lower pressing cap 27 is connected with the rubber cylinder 25 through a lower connecting sleeve 26; at least two groups of sealing rings 28 are sleeved on the outer wall of the sealing pull cylinder 21; the first bolt group 29 and the second bolt group 210 are positioned at one end of the sealing pull cylinder 21 exposed out of the upper main body 24; the first shear bolt set 13 is located between the first bolt set 29 and the second bolt set 210; the end of the upper gland 22 adjacent the delivery device 1 has a radially projecting boss.

The sealing pull cylinder 21 is used for driving the upper main body 24 to move towards the direction close to the wellhead. The upper connecting sleeve 23 is used for connecting the upper pressing cap 22 and the rubber cylinder 25; the lower connecting sleeve 26 is used for connecting the lower pressing cap 27 and the rubber cylinder 25. The upper pressing cap 22 and the lower pressing cap 27 are used for fixing the rubber cylinder 25 and preventing the rubber cylinder 25 from axially moving along the surface of the upper main body 24.

The top end of the upper body 24 has an inner diameter smaller than the middle portion of the upper body 24 and protrudes inwardly to form an inner step. The cavity of the upper main body 24 is provided with an upper liquid passing hole and a lower liquid passing hole. The bottom end of the upper body 24 is provided with external threads for attachment to the lower body 31. The upper body 24 is used for providing a liquid passing channel; the upper body 24 also serves to limit the detachment of the sealing sleeve 21 from the upper body 24. The liquid passing hole close to the top end of the upper main body 24 is used for discharging liquid in the rubber cylinder 25 so as to balance the pressure between the upper main body 24 and the rubber cylinder 25 and play a role in relieving pressure and releasing sealing; the liquid through hole far away from the top end of the upper main body 24 is used for downhole liquid to enter the rubber cylinder 25, so that the rubber cylinder 25 is radially expanded to provide sealing pressure for the rubber cylinder 25.

The packing 25 is used to expand by radial expansion to seal the annular space between the tubing plug and the mandrel. Illustratively, the glue cartridge 25 is an expanding glue cartridge. Illustratively, a threaded connection is used between the upper connecting sleeve 23 and the upper pressure cap 22. Illustratively, a threaded connection is used between the lower nipple 26 and the lower cap 27.

In an alternative embodiment, as shown in fig. 1, the top and middle outer diameters of the sealing sleeve 21 are smaller than the outer diameter of the bottom end of the sealing sleeve 21, forming a bottom boss. The inner diameters of the middle part and the lower part of the inner cavity of the sealing pull cylinder 21 are smaller than the inner diameter of the upper part of the inner cavity of the sealing pull cylinder 21, so that a diameter-reducing part is formed.

The barrel body on the upper edge of the boss at the bottom of the sealing pull barrel 21 is provided with a pressure relief hole which penetrates through the inner wall and the outer wall of the sealing pull barrel 21. The middle part and the bottom outer wall of the sealing pull cylinder 21 are respectively provided with a sealing ring 28. The first bolt group 29 is a pair of bolts symmetrically distributed along the axis of the sealing pull cylinder 21; the first bolt group 29 is a pair of bolts symmetrically distributed along the axis of the seal pulling barrel 21. The first bolt group 29 is installed on the top end outer wall of the sealing pulling barrel 21 along the radial direction of the sealing pulling barrel 21. The second bolt group 210 is installed on the top end outer wall of the sealing pulling cylinder 21 along the radial direction of the sealing pulling cylinder 21. Illustratively, the first bolt set 29, the first shear bolt set 13, the second bolt set 210 and the second shear bolt set 14 are sequentially arranged on the same straight line and are parallel to each other.

The first bolt set 29 is used for driving the sealing pull cylinder 21 to move away from the upper main body 24. The first bolt set 29 is also used to shear the first shear pin set 13. The second bolt group 210 is used for positioning when the delivery barrel 12 is mounted, so that the lower edge of the first shear bolt group 13 is in contact with the upper edge of the second bolt group 210.

In an alternative embodiment, as shown in fig. 1, the locking portion 3 of the tubing plug provided in the embodiments of the present application includes a lower body 31, a shaft 32, a cam 33, and a torsion spring 34.

At least one set of seal rings 28 is sleeved on the lower main body 31; the top end of the lower body 31 is connected with the upper body 24; the shaft 32 is mounted in the lower body 31; the cam 33 is mounted on the shaft 32; torsion spring 34 is sleeved on shaft 32; the torsion spring 34 is connected to the cam 33, and the cam is maintained in a radially opened state by the elasticity of the torsion spring 34.

Lower main part 31 is the conical barrel for the bottom, and barrel upper portion sets up a set of through-hole, and the barrel lower extreme sets up a pore. The lower side wall of the lower main body 31 is provided with a through groove with a rectangular cross section, and the normal direction of the through groove is provided with a group of round through holes. The shaft 32 is mounted on a circular through hole provided upward in the through groove method. A group of through holes arranged at the upper part of the cylinder body are used for installing a third shear pin group 43; a blind hole arranged at the lower end of the cylinder body is used for connecting the torsion spring 34; the through groove with the rectangular section is used for providing a space for the cam 33 to contract or expand and providing a passage for downhole liquid to enter the tubing plug; a set of circular through holes is used to mount the shaft 32.

As shown in fig. 1, a cam 33 is mounted on the shaft 32, and the cam 33 can perform limited rotation about the shaft 32. The long claws of the cam 33 are movable in the through slots in the lower part of the lower body 31. Torsion spring 34 is fitted over shaft 32, one end of torsion spring 34 is pressed inside the long jaw of cam 33, and the other end of torsion spring 34 is inserted into the blind hole in the lower end of lower body 31.

The lower body 31 is used to connect the locking portion 3 to the sealing portion 2. The cam 33 is used to lock the tubing stopper in the mandrel. The torsion spring 34 is used to restore the cam 33 to its original posture after the cam 33 passes through the reduced diameter portion of the cylinder.

In an alternative embodiment, as shown in fig. 1, the unset section 4 of the tubing plug provided by the example of the present application includes an upper pull rod 41, a lower pull rod 42, and a third shear pin set 43.

The upper pull rod 41 axially penetrates through the inner cavity of the sealing pull cylinder 21, the top end of the upper pull rod 41 is positioned outside the sealing pull cylinder 21, and the bottom end of the upper pull rod 41 is positioned inside the upper main body 24; the top end of the lower pull rod 42 is connected with the bottom end of the upper pull rod 41; the lower end of the lower link 42 is connected to the lower body 31 by a third scissor set 43.

The top end of the upper pull rod 41 is a conical step, and the bottom end of the upper pull rod 41 is provided with an external thread. The outer diameter of the middle part of the upper pull rod 41 is larger than the outer diameters of the top end and the bottom end of the upper pull rod 41, two groups of sealing ring grooves are formed in the middle part of the upper pull rod 41, and two groups of sealing rings 28 are installed in the two groups of sealing ring grooves. The outer diameter of the middle part of the upper pull rod 41 is equal to the inner diameter of the middle lower part of the sealing pull cylinder 21.

The top end of the lower pull rod 42 is provided with an axial blind hole, and the inner wall of the axial blind hole is provided with internal threads. The bottom end of the upper pull rod 41 is connected with the top end of the lower pull rod 42 through screw threads. The outer diameter of the lower part of the lower pull rod 42 is larger than the outer diameters of the upper part and the middle part of the lower pull rod 42, and the lower pull rod is in a boss shape. The outer wall circumference of the boss at the lower part of the lower pull rod 42 is provided with a ring-shaped groove. The third staple set 43 is a pair of staples. The third shear pin group 43 passes through the through hole at the upper part of the lower body 31 and then is inserted into the annular groove on the outer wall circumference of the boss at the lower part of the lower pull rod 42.

As shown in fig. 1, an alternative assembly method of the tubing plug provided by the embodiment of the present application is as follows:

two sets of sealing rings 28 are respectively installed in two sets of sealing ring grooves on the outer wall of the sealing pull cylinder 21. The sealing pull cylinder 21 is installed in the inner cavity of the upper main body 24, so that the top end of the sealing pull cylinder 21 is exposed out of the upper main body 24. The first bolt set 29 and the second bolt set 210 are mounted on the seal pulling barrel 21.

The rubber cylinder 25 is sleeved on the outer wall of the upper main body 24, so that the rubber cylinder 25 is positioned between the upper connecting sleeve 23 and the lower connecting sleeve 26. The upper and lower pressure caps 22 and 27 are mounted to the upper and

lower connection sleeves

23 and 26, respectively.

Inserting the upper pull rod 41 into the sealing pull cylinder 21 from the side of the top end of the sealing pull cylinder 21 with the first bolt group 29, so that the conical step part at the top end of the upper pull rod 41 is positioned outside the sealing pull cylinder 21; the part with larger outer diameter in the middle of the upper pull rod 41 is positioned in the reduced diameter part of the sealing pull cylinder 21. The lower link 42 is inserted into the upper body 24 from the end opposite to the upper link 41, so that the top end of the lower link 42 is screw-coupled to the bottom end of the upper link 41.

The cam 33 is mounted on the shaft 32. Torsion spring 34 is fitted over shaft 32 so that one end of torsion spring 34 presses against the inside of the long jaw of cam 33. The shaft 32 is fitted into a circular through hole provided in a normal direction of the through groove in the lower side wall of the lower body 31, and the other end of the torsion spring 34 is inserted into a fine hole in the lower end of the lower body 31. The lower body 31 is connected to the upper body 24 such that the through hole in the upper portion of the lower body 31 is aligned with the annular groove in the outer wall circumference of the boss in the lower portion of the lower link 42, and the cam 33 abuts against the bottom end of the lower link 42. The third nail group 43 is inserted into the through hole in the upper portion of the lower body 31 such that the end of the third nail group 43 is inserted into the annular groove in the outer circumference of the lower boss of the lower drawbar 42.

The delivery cylinder 12 and the sealing pull cylinder 21 are connected through the first shear pin set 13, and the first shear pin set 13 is located between the first bolt set 29 and the second bolt set 210. The delivery cylinder 12 and the upper body 24 are connected by the second scissor set 14, and the rope end 11 is connected with the delivery cylinder 12.

An optional use process of the oil pipe plug provided by the embodiment of the application is as follows:

two sets of sealing rings 28 are respectively installed in two sets of sealing ring grooves on the outer wall of the sealing pull cylinder 21. The sealing pull cylinder 21 is sleeved into the inner cavity of the upper main body 24, so that the top end of the sealing pull cylinder 21 is exposed out of the upper main body 24. The first bolt set 29 and the second bolt set 210 are mounted on the seal pulling barrel 21.

The rubber cylinder 25 is sleeved on the outer wall of the upper main body 24, so that the rubber cylinder 25 is positioned between the upper connecting sleeve 23 and the lower connecting sleeve 26. The upper and lower push caps 22 and 27 are fitted to the upper and

lower connection sleeves

23 and 26, respectively.

Inserting the upper pull rod 41 from the side of the sealing pull cylinder 21 having the first bolt group 29 so that the conical portion of the top end of the upper pull rod 41 is positioned outside the sealing pull cylinder 21; the part of the upper pull rod 41 with the larger outer diameter in the middle is positioned in the part of the sealing pull cylinder 21 with the smaller inner diameter. The lower rod 42 is inserted into the upper body 24 such that the top end of the lower rod 42 is threadedly coupled to the bottom end of the upper rod 41.

The cam 33 is mounted on the shaft 32. Torsion spring 34 is fitted over shaft 32 such that one end of torsion spring 34 is pressed against the inside of the long jaw of cam 33. The shaft 32 is fitted into a circular through hole provided in a normal direction of the through groove in the lower side wall of the lower body 31, and the other end of the torsion spring 34 is inserted into a fine hole in the lower end of the lower body 31. The lower body 31 is coupled to the upper body 24 such that the through-hole of the upper portion of the lower body 31 is aligned with the annular groove formed on the outer circumference of the boss of the lower portion of the lower link 42 and the lower end of the lower link 42 is abutted against the cam 33. The third nail group 43 is inserted into the through hole at the upper part of the lower body 31, so that the third nail group 43 is inserted into the annular groove on the outer wall circumference of the boss at the lower part of the lower pull rod 42.

The delivery cylinder 12 and the sealing pull cylinder 21 are connected by the first shear pin set 13, and the first shear pin set 13 is arranged between the first bolt set 29 and the second bolt set 210. One end of the steel wire is passed through the through hole at the tip of the tapered portion of the rope end 11 and the steel wire is knotted through the one end of the rope end 11. The rope end 11 is connected with the delivery cylinder 12.

The tubing plug provided by the embodiment of the application is sent into a downhole tubular column in a posture that a rope head 11 faces upwards. When the tubing plug provided by the embodiment of the application enters the reduced diameter part of the working barrel, the long claws of the cam 33 contract radially. After the cam 33 passes through the working barrel, the lower edge of the boss of the upper pressing cap 22 is pressed on the diameter reducing step of the working barrel, and meanwhile, the long claw of the cam 33 is radially expanded and clamped on the lower edge of the working barrel.

The steel wire is lifted upwards to drive the delivery barrel 12 to move upwards, so that the second shear pin group 14 is sheared, and the first shear pin group 13 is overlapped with the first bolt group 29. The steel wire is lifted up continuously, so that the first shear pin group 13 drives the sealing pull cylinder 21 to move upwards through the first bolt group 29 until the sealing pull cylinder 21 is blocked by the inner step of the upper main body 24. The steel wire is lifted upwards continuously, so that the first shear bolt group 13 is sheared by the first bolt group 29, and the rope head 11 and the delivery barrel 12 are separated from the lower tool.

And releasing the pressure of the water injection well at the well mouth to make the downhole liquid enter the tubing plug. The liquid entering the tubing plug enters a closed annular space between the upper main body 24 and the rubber cylinder 25 through a liquid passing hole on the cavity of the upper main body 24, so that the rubber cylinder 25 is radially expanded. At the moment, the outer wall of the rubber cylinder 25 is tightly attached to the inner wall of the working cylinder, so that the annular space between the oil pipe plug and the working cylinder is sealed.

The higher the downhole liquid pressure is, the higher the liquid pressure in the rubber cylinder 25 is, and the tighter the sealing between the rubber cylinder 25 and the inner wall of the working cylinder is.

An optional lifting mode of the oil pipe plug provided by the embodiment of the application is as follows:

the fishing tool is lowered into the underground pipe column through the steel wire, so that the fishing tool hooks the bottom surface of the conical step of the upper pull rod 41. The upper pull rod 41 is driven by lifting the steel wire upwards, and the lower pull rod 42 is driven by the upper pull rod 41, so that the third shear nail group 43 is sheared off. The steel wire is lifted up continuously, so that the bottom end of the lower pull rod 42 is disengaged from the cam 33, and the limitation of the lower pull rod 42 on the cam 33 is released. And continuously lifting the steel wire to enable the part with the larger diameter in the middle of the upper pull rod 41 to be separated from the diameter-reduced part of the sealing pull cylinder 21, and at the moment, a gap exists between the upper pull rod 41 and the sealing pull cylinder 21.

At the moment, the upper space and the lower space of the tubing plug are communicated, liquid between the upper main body 24 and the rubber sleeve 25 and liquid in a tubular column at the lower part of the tubing plug can enter the tubular column at the upper part of the tubing plug through a gap between the upper pull rod 41 and the sealing pull cylinder 21, finally, the pressure of the upper tubular column and the lower tubular column of the tubing plug is gradually balanced, the rubber sleeve 25 retracts radially, and the sealing of the working cylinder is released. And continuously lifting the steel wire, and fishing out the tubing plug from the wellhead.

In an alternative embodiment, the operations of the tubing plug provided in the examples herein include at least delivering, locking, sealing, and unsetting. Illustratively, the tubing plug provided by the embodiments of the present application operates as follows:

two sets of sealing rings 28 are respectively installed in two sets of sealing ring grooves on the outer wall of the sealing pull cylinder 21. The sealing pull cylinder 21 is sleeved into the inner cavity of the upper main body 24, so that the top end of the sealing pull cylinder 21 is exposed out of the upper main body 24. The first bolt group 29 and the second bolt group 210 are mounted on the sealing pulling cylinder 21. The rubber cylinder 25 is sleeved on the outer wall of the upper main body 24, so that the rubber cylinder 25 is positioned between the upper connecting sleeve 23 and the lower connecting sleeve 26. The upper and lower pressure caps 22 and 27 are mounted to the upper and

lower connection sleeves

23 and 26, respectively.

Inserting the upper pull rod 41 from the side of the top end of the sealing pull cylinder 21 with the first bolt group 29, so that the conical part of the top end of the upper pull rod 41 is positioned outside the sealing pull cylinder 21; the part of the upper pull rod 41 with the larger outer diameter in the middle is positioned in the part of the sealing pull cylinder 21 with the smaller inner diameter. The lower rod 42 is inserted into the upper body 24 such that the top end of the lower rod 42 is threadedly coupled to the bottom end of the upper rod 41.

The cam 33 is mounted on the shaft 32. Torsion spring 34 is fitted over shaft 32 such that one end of torsion spring 34 is pressed against the inside of the long jaw of cam 33. The shaft 32 is fitted into a circular through hole provided in a normal direction of the through groove in the lower side wall of the lower body 31, and the other end of the torsion spring 34 is inserted into a fine hole in the lower end of the lower body 31. The lower body 31 is coupled to the lower cap 27 such that the through-hole of the upper portion of the lower body 31 is aligned with the annular groove of the outer wall of the lower boss of the lower rod 42, and the lower end of the lower rod 42 is abutted against the cam 33. The third nail group 43 is inserted into the through hole at the upper part of the lower body 31, so that the third nail group 43 is inserted into the annular groove on the outer wall circumference of the boss at the lower part of the lower pull rod 42.

The delivery cylinder 12 and the sealing pull cylinder 21 are connected through the first shear pin set 13, and the first shear pin set 13 is located between the first bolt set 29 and the second bolt set 210. The delivery cartridge 12 and the upper body 24 are connected by the second shear pin set 14. One end of the steel wire is passed through the through hole at the tip of the tapered portion of the rope end 11 and knotted. The rope end 11 is connected with the delivery cylinder 12.

The tubing plug provided by the embodiment of the application is sent into a downhole tubular column in a posture that a rope head 11 faces upwards. When the oil pipe plug moves downwards to enter the working barrel, the cam 33 rotates, and the long claw of the cam 33 contracts, so that the oil pipe plug can enter the reducing section of the working barrel. After the cam 33 of the oil pipe plug passes through the reducing section of the working barrel, the cam 33 is reset under the action of the torsion spring 34, and the long claw of the cam 33 clamps the lower edge of the reducing section of the working barrel. Illustratively, when the long claw of the cam 33 catches the lower edge of the reduced diameter section of the work cylinder, the other end of the cam 33 is restrained by the lower tie rod 42 as shown in fig. 1, and the cam 33 cannot rotate freely around the shaft 32.

When the cam 33 catches the lower edge of the working barrel, the lower edge of the boss of the upper pressing cap 22 of the upper main body 24 presses on the upper edge of the reducing section of the working barrel, and the locking part locks the oil pipe plug provided by the embodiment of the application in the reducing section of the working barrel.

After the position of the tubing plug is locked, the steel wire is lifted up to drive the delivery barrel 12 to move upwards, so that the second shear bolt group 14 is sheared, and the first shear bolt group 13 is overlapped with the first bolt group 29. The steel wire is lifted up continuously, so that the first shear pin group 13 drives the sealing pull cylinder 21 to move upwards through the first bolt group 29 until the sealing pull cylinder 21 is blocked by the inner step of the upper main body 24. At this time, the liquid passing hole on the cavity of the upper main body 24, which is far away from the top end of the upper main body 24, is exposed, so that the inner cavity of the upper main body 24 is communicated with the inner cavity of the rubber cylinder 25. The liquid through hole on the cavity of the upper main body 24 close to the upper main body 24 is aligned with the pressure relief hole on the sealing pull cylinder 21. When the sealing pulling barrel 21 moves upwards, the part with larger diameter in the middle of the upper pull rod 41 enters the reduced diameter part in the sealing pulling barrel 21, so that the pressure relief hole of the sealing pulling barrel 21 is blocked by the part with larger diameter in the middle of the upper pull rod 41.

And the steel wire is lifted continuously, so that the first shear screw group 13 is sheared by the first bolt group 29, and the rope head 11 and the delivery barrel 12 are separated from the tubing plug. At the moment, the pressure of the water injection well is released at the well mouth, the upper pressure of the oil pipe plug is smaller than the lower pressure of the oil pipe plug, and the formation liquid enters the oil pipe plug from the lower part of the oil pipe plug. Liquid enters the upper main body from gaps between the lower pull rod 42 and the upper pull rod 41 and the upper main body 24, and enters a space between the rubber cylinder 25 and the upper main body 24 from a liquid passing hole exposed from the upper main body 24. Due to the entry of the pressurized liquid, the rubber sleeve 25 expands along the radial direction, so that the outer wall of the rubber sleeve 25 is tightly attached to the inner wall of the reducing section of the working barrel, and the space above and below the oil pipe plug is separated.

The downhole liquid pressure on the lower part of the oil pipe plug is higher, the liquid pressure entering the inside of the rubber cylinder 25 is higher, the contact stress between the rubber cylinder 25 and the inner wall of the diameter-reducing section of the working cylinder is higher, the rubber cylinder 25 is more tightly attached to the inner wall of the diameter-reducing section of the working cylinder, and the sealing effect is better.

Illustratively, when there is an anomaly in the downhole string, the tubing plug needs to be fished, at which time the seal needs to be unsealed and the tubing plug lifted out. The specific operation is as follows:

the fishing tool is lowered into the underground pipe column through the steel wire, so that the fishing tool hooks the bottom surface of the conical step of the upper pull rod 41. The upper pulling wire drives the upper pulling rod 41, and the upper pulling rod 41 drives the lower pulling rod 42, so that the third shear nail group 43 is sheared. And continuously lifting the steel wire to disengage the bottom end of the lower pull rod 42 from the cam 33, and releasing the limitation of the lower pull rod 42 on the cam 33. And continuously lifting the steel wire to ensure that the part with the larger diameter in the middle of the upper pull rod 41 is separated from the diameter-reduced part of the sealing pull cylinder 21, and a gap exists between the upper pull rod 41 and the sealing pull cylinder 21.

At the moment, the upper space and the lower space of the oil pipe plug are communicated, liquid between the upper main body 24 and the rubber sleeve 25 and liquid in a pipe column at the lower part of the oil pipe plug can enter the pipe column at the upper part of the oil pipe plug through a gap between the upper pull rod 41 and the sealing pull cylinder 21, finally, the upper pressure and the lower pressure of the oil pipe plug are gradually balanced, the rubber sleeve 25 retracts radially, and the sealing of the working cylinder is released. And continuously lifting the steel wire, and fishing out the tubing plug from the wellhead.

In summary, the oil pipe plug provided by the embodiment of the application finishes delivery by connecting the delivery part with the steel wire, and the boss of the upper pressure cap and the long claw of the cam clamp two ends of the working barrel, so that the position of the oil pipe plug is locked; the delivery part is separated from the oil pipe plug by lifting the steel wire, and the liquid with pressure in the well enters the rubber sleeve in the separation process, so that the rubber sleeve is radially expanded to complete sealing, and the sealing performance is better when the pressure of the liquid in the well is higher. When the oil pipe plug needs to be pulled out, the fishing tool is used for lifting the upper pull rod to release the sealing and the locking of the locking part on the position of the oil pipe plug, so that the oil pipe plug is completely pulled out along with the fishing tool. The tubing plug can be reassembled after being taken out and then can be repeatedly put into use and recycled.

The above description is intended only to serve as examples of the present application and should not be construed as limiting the present application, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present application should be included in the scope of the present application.

Claims

1. The oil pipe plug is characterized by comprising a delivery device (1), a sealing device (2), a locking device (3) and an unsealing device (4);

wherein one end of the delivering device (1) is connected with a delivering and fishing tool; the other end of the delivery device (1) is connected with one end of the sealing device (2), and the other end of the sealing device (2) is connected with the locking device (3); the unsealing device (4) is positioned in the cavity of the sealing device (2);

the delivery device (1) is used for delivering the oil pipe plug into a working barrel at a reference position in the underground oil pipe; the sealing device (2) is used for sealing a gap between the working barrel and the tubing plug by using the pressure of downhole liquid; the locking device (3) is used for locking the oil pipe plug in the working barrel and preventing the oil pipe plug from moving up and down; the unsealing device (4) is used for unsealing the working barrel by the sealing device (2) and unlocking the position of the tubing plug by the locking device (3) when the tubing plug is recovered, so that the tubing plug is recovered for repeated delivery.

2. Tubing plug according to claim 1, characterized in that the delivery device (1) comprises a string head (11), a delivery barrel (12), a first shear pin group (13) and a second shear pin group (14);

one end of the rope head (11) is connected with a throwing and fishing tool, and the other end of the rope head (11) is connected with one end of the throwing and delivering cylinder (12); the other end of the delivery cylinder (12) is connected with the sealing device (2); the other end of the delivery barrel (12) is sequentially provided with the first shear pin group (13) and the second shear pin group (14);

the first shear pin group (13) is a group of shear pins which are symmetrically distributed along the axis of the delivery cylinder (12);

the second shear pin group (14) is a group of shear pins which are symmetrically distributed along the axis of the delivery cylinder (12).

3. The tubing plug according to claim 2, wherein the sealing device (2) comprises a sealing pull cylinder (21), an upper pressure cap (22), an upper connecting sleeve (23), an upper main body (24), a rubber cylinder (25), a lower connecting sleeve (26), a lower pressure cap (27), a sealing ring (28), a first bolt group (29) and a second bolt group (210);

one end of the sealing pull cylinder (21) is arranged in the cavity of the upper main body (24), and the other end of the sealing pull cylinder (21) is exposed out of the upper main body (24); the rubber cylinder (25) is sleeved outside the upper main body (24); the upper connecting sleeve (23) and the lower connecting sleeve (26) are positioned on the outer wall of the upper main body (24); the upper pressing cap (22) is positioned at one end of the rubber cylinder (25), and the lower pressing cap (27) is positioned at the other end of the rubber cylinder (25); the upper pressure cap (22) is connected with the rubber cylinder (25) through the upper connecting sleeve (23); the lower pressing cap (27) is connected with the rubber cylinder (25) through the lower connecting sleeve (26); at least two groups of sealing rings (28) are sleeved on the outer wall of the sealing pull cylinder (21); the first bolt group (29) and the second bolt group (210) are positioned at one end of the sealing pull cylinder (21) exposed out of the upper main body (24); the first set of shear bolts (13) is located between the first set of bolts (29) and the second set of bolts (210); one end of the upper pressing cap (22) close to the delivery device (1) is provided with a boss protruding radially; the upper body (24) is connected with the delivery barrel (12) through the second shear pin group (14).

4. Tubing plug according to claim 3, characterised in that said locking portion (3) comprises a lower body (31), a shaft (32), a cam (33) and a torsion spring (34);

wherein at least one group of sealing rings (28) is sleeved on the lower main body (31); the top end of the lower main body (31) is connected with the upper main body (24); the shaft (32) is mounted within the lower body (31); the cam (33) is mounted on the shaft (32); the torsion spring (34) is sleeved on the shaft (32); the torsion spring (34) is connected with the cam (33), and the cam (33) is in a radial expansion state through the elasticity of the torsion spring (34).

5. Tubing plug according to claim 4, characterized in that said deblocking section (4) comprises an upper pull rod (41), a lower pull rod (42) and a third shear set (43);

the upper pull rod (41) axially penetrates through an inner cavity of the sealing pull cylinder (21), the top end of the upper pull rod (41) is located outside the sealing pull cylinder (21), and the bottom end of the upper pull rod (41) is located inside the upper main body (24); the top end of the lower pull rod (42) is connected with the bottom end of the upper pull rod (41); the bottom end of the lower pull rod (42) is connected with the lower main body (31) through the third shear pin group (43).

6. Tubing plug according to claim 3 or 5, characterized in that the outer diameter of the top and middle part of the sealing pull cylinder (21) is smaller than the outer diameter of the bottom end of the sealing pull cylinder (21), forming a bottom boss.

7. The tubing plug according to claim 3 or 5, characterized in that the cylinder body on the upper edge of the boss at the bottom of the sealing pull cylinder (21) is provided with a pressure relief hole.

8. Tubing plug according to claim 4 or 5, characterized in that said lower body (31) is a cylinder with a conical bottom, said cylinder being provided with a set of through holes at its upper end and a blind hole at its lower end; a through groove with a rectangular cross section is arranged on the side wall of the lower part of the lower main body (31), and a group of round through holes are upwards arranged in the through groove;

the group of through holes arranged at the upper part of the cylinder body is used for installing the third shear pin group (43); the blind hole arranged at the lower end of the cylinder body is used for connecting the torsion spring (34); the through groove with the rectangular cross section is used for providing space for the cam (33) to contract or expand and providing a passage for downhole liquid to enter the tubing plug; the set of circular through holes is used for mounting the shaft (32).

9. Tubing plug according to claim 8, characterized in that one end of said torsion spring (34) is pressed inside the long claw of the cam (33) and the other end of said torsion spring (34) is inserted into the blind hole in the lower end of said lower body (31).

10. The tubing plug as claimed in claim 5, wherein the top end of the upper pull rod (41) is a conical step, and the bottom end of the upper pull rod (41) is provided with an external thread; the top end of the lower pull rod (42) is provided with an axial blind hole, and the inner wall of the axial blind hole is provided with internal threads; the bottom end of the upper pull rod (41) is connected with the top end of the lower pull rod (42) through threads.