CN221144373U

CN221144373U - Downhole fishing tool

Info

Publication number: CN221144373U
Application number: CN202323206442.5U
Authority: CN
Inventors: 刘涛; 赵伟; 胡丹; 陈晨; 滕汶江; 周怡君
Original assignee: China Petroleum and Chemical Corp; Sinopec Southwest Oil and Gas Co
Current assignee: China Petroleum and Chemical Corp; Sinopec Southwest Oil and Gas Co
Priority date: 2023-11-27
Filing date: 2023-11-27
Publication date: 2024-06-14
Anticipated expiration: 2033-11-27

Abstract

The utility model belongs to the technical field of downhole tools for oil and gas wells, and particularly relates to a downhole fishing tool. The downhole fishing tool comprises a cylinder sleeve, a central tube and a working part. The center tube includes a tube body and a cone. The working part comprises a piston sleeved between the cylinder sleeve and the central tube and a salvaging mechanism connected to the lower end of the piston. The piston is configured to drive the fishing mechanism to slide downwards in response to the increase of pressure, and the fishing mechanism is configured to expand radially in response to the change of the cone shape in the sliding process, so that the fishing mechanism can fish the fish out of the well. The underground fishing tool provided by the utility model has the advantages of simple structure and convenience in operation, can safely and efficiently fish the fish in the underground, and has a wide application prospect in the field.

Description

Downhole fishing tool

Technical Field

The utility model belongs to the technical field of downhole tools for oil and gas wells, and particularly relates to a downhole fishing tool.

Background

Foreign matter, commonly referred to as fish, is formed in the well due to mishandling, accidents in downhole construction, actual demands for well construction operations of oil and gas wells, and the like. For the fishes in different forms, a fishing tool matched with the fishes is often required to be designed for fishing, and the fishes are taken out of the shaft so as to keep the smoothness of the shaft.

The tool for fishing the fish with the hollow cylindrical structure in the prior art has the defects of complex structure, low fishing efficiency and the like, and forms restriction on safe, efficient and stable underground operation.

Disclosure of utility model

Aiming at the problems in the prior art, the utility model provides a downhole fishing tool.

The downhole fishing tool includes:

A cylinder liner configured as a hollow tubular structure;

The central tube is at least partially arranged inside the cylinder sleeve and comprises a tube body and a cone arranged below the tube body, wherein the cone comprises an expansion part and a guide part, the expansion part is configured to have an outer contour which gradually extends from the middle to the periphery in the direction from top to bottom, and the guide part is connected below the expansion part and is configured to have at least part of the outer contour not smaller than the maximum radial dimension of the cylinder sleeve; and

The working part comprises a piston sleeved between the cylinder sleeve and the central tube and a salvaging mechanism connected to the lower end of the piston, the piston and the cylinder sleeve are fixedly connected,

The piston is configured to be separated from the cylinder sleeve in response to the increase of pressure and drive the fishing mechanism to slide downwards, and the fishing mechanism is configured to be capable of radial expansion in response to the change of the cone shape in the sliding process, so that the fishing mechanism can fish the fish out of the well.

As an extension of the above technical solution, the present utility model further provides the following embodiments:

The cylinder sleeve is provided with a groove corresponding to the C-shaped clamp spring, and when the C-shaped clamp spring slides to the groove in the sliding process, the pre-tightened C-shaped clamp spring is sprung out and embedded into the groove to terminate the sliding.

The upper end of the central tube is provided with a ball seat which can accommodate the pressure-holding ball to perform pressure holding operation.

And a liquid inlet hole which is convenient for liquid to enter and apply pressure to the piston is arranged on the central tube.

The salvaging mechanism is a plurality of elastic claws distributed along the circumferential direction of the piston.

A first sealing ring is arranged between the cylinder sleeve and the piston.

A second sealing ring is arranged between the central tube and the piston.

An upper joint is arranged at the position between the central tube and the cylinder sleeve.

A third sealing ring is arranged between the central pipe and the upper joint.

And a fourth sealing ring is arranged between the cylinder sleeve and the upper joint.

Compared with the prior art, the utility model has the advantages that:

The technical scheme provided by the utility model has the advantages of simple structure, low manufacturing cost, convenience in operation and high working efficiency and safety, and is particularly suitable for salvaging the hollow cylindrical fish.

Drawings

FIG. 1 is a schematic diagram of a downhole fishing tool according to the present utility model;

FIG. 2 is a schematic view of the downhole fishing tool according to the present utility model in an operational state.

All of the drawings in the present utility model are schematic for illustrating the structure and principles and are not necessarily drawn to scale and in actual size.

The specific meaning of each reference numeral in the figures is as follows:

1. Cylinder sleeve; 11. a groove; 12. a pin; 2. a central tube; 21. a tube body; 22. a cone; 221. an expansion section; 222. a guide section; 23. a ball seat; 24. a liquid inlet hole; 25. a second seal ring; 26. a third seal ring; 3. a working section; 31. a piston; 311. c-shaped clamp springs; 312. a first seal ring; 32. a salvaging mechanism; 320. an elastic claw; 3201. a connecting rod; 3202. a protruding portion; 4. a fish drop; 5. a pressing ball is pressed; 6. an upper joint; 61. a fourth seal ring; 100. a downhole fishing tool.

Detailed Description

Embodiments of the present utility model will be described in more detail below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a downhole fishing tool 100 according to the present utility model. As shown, the downhole fishing tool 100 includes a cylinder liner 1, a base pipe 2, and a working portion 3. The cylinder liner 1 is constructed as a hollow tubular structure. The central tube 2 is also a hollow column as a whole, is provided at least partially inside the cylinder liner 1 by penetrating the hollow portion of the cylinder liner 1, and includes a tube body 21 at the upper portion and a cone 22 provided below the tube body 21. The cone 22 comprises an expansion 221 which is configured to be hollow internally and has an outer contour which extends gradually from the middle to the periphery in the direction from top to bottom, and a guide 222 which is also configured to be hollow internally and is configured such that at least part of the outer contour is not smaller than the maximum radial dimension of the cylinder liner 1, which is connected below the expansion 221. The working part 3 comprises a piston 31 and a salvaging mechanism 32, wherein the piston 31 is sleeved between the cylinder sleeve 1 and the central tube 2, the salvaging mechanism 32 is connected to the lower end of the piston 31, and the piston 31 is fixedly connected with the cylinder sleeve 1. In addition, the piston 31 is further configured to be separated from the cylinder sleeve 1 in response to the increase of pressure and drive the fishing mechanism 32 to slide downwards, and the fishing mechanism 32 is further configured to be radially expanded in response to the change of the profile of the cone 22 in the process of sliding the piston 31 downwards, so that the down-hole fish 4 can be fished out of the well in the subsequent operation process.

As shown in fig. 1 and 2, in a specific operation, a worker connects the downhole fishing tool 100 to the lower end of a coiled tubing (not shown, the same applies below) and feeds the downhole fishing tool 100 through the coiled tubing into a suitable location downhole, typically within the fish 4 or at a location after passing through the fish 4. In the running process, the guiding part 222 at the lowest end can perform preliminary detection on the size of the inner space of the shaft and the inner space of the fish 4 due to the self-construction, so that guiding and safety guarantee effects can be provided for the subsequent running components to smoothly run into the well. When the fishing tool 100 is in place, the piston 31 is separated from the cylinder sleeve 1 by applying pressure and drives the fishing mechanism 32 connected below the piston 31 to slide downwards. The fishing mechanism 32 will move down the outer contour of the cone 22 during this sliding motion. Due to the nature of the configuration of the expansion 221 in the cone 22, radial expansion of the fishing mechanism 32 occurs during the sliding motion. When the size of the fishing mechanism 32 in the radial direction is enlarged to be not smaller than the inner diameter of the fish 4, the fish 4 can be lifted up together with the fishing mechanism 32 by the clamping action of the fishing mechanism 32 in the inside thereof or by the pushing action of the fishing mechanism 32 in the lower part thereof by lifting the downhole fishing tool 100 up through the coiled tubing, and finally fished out of the well.

Through the design, the fishing out of the well of the fish 4 with the hollow cylindrical structure is conveniently, quickly and efficiently realized, and the downhole fishing tool 100 provided by the utility model has the advantages of simple structure, low manufacturing cost, high economy and high safety, and has good potential for large-scale production and application.

In one embodiment of the present utility model, as shown in fig. 1, the uppermost end of the expansion portion 221 has an outer diameter not greater than the outer diameter of the pipe body 21 in order to facilitate the sliding of the fishing mechanism 32.

In one embodiment of the utility model, as shown in fig. 1, the piston 31 is fixedly connected to the cylinder liner 1 by means of a pin 12. When the pin 12 is subjected to pressure from the piston 31 and the pressure is transmitted to exceed the load, the pin 12 is sheared, and the piston 31 drives the salvaging mechanism 32 to slide downwards. By means of the design, the fixed connection and separation between the piston 31 and the cylinder sleeve 1 are simply and conveniently realized, and a structural basis is provided for realizing the subsequent functions of the downhole fishing tool 100.

As shown in fig. 1, in one embodiment of the present utility model, a C-shaped clamp spring 311 is provided at an outer wall of the piston 31, and a groove 11 corresponding to the C-shaped clamp spring 311 is provided on the cylinder liner 1. In the process that the piston 31 drives the salvaging mechanism 32 to slide, when the C-shaped clamp spring 311 slides to the groove 11, the C-shaped clamp spring 311 in the pre-tightening state is sprung out due to expansion of space and is embedded into the groove 11, and because the C-shaped clamp spring 311 is also partially structurally embedded into the piston 31, the C-shaped clamp spring 311 is simultaneously embedded into the piston 31 and the cylinder sleeve 1, and the C-shaped clamp spring 311 also plays a role in preventing the piston 31 from continuously sliding downwards. By means of the design, when the piston 31 drives the fishing mechanism 32 to slide downwards to a proper position, sliding can be stopped, so that the situation that the piston 31 is separated from other parts of the downhole fishing tool 100 due to over-sliding is avoided, and the stability and the integrity of the structure of the downhole fishing tool 100 are ensured. The upper end of the fishing mechanism 32 is provided with a fixed point in the subsequent fishing process of the fish so as to conveniently exert force, thereby ensuring the smooth fishing operation of the downhole fishing tool 100.

As shown in fig. 1, in an embodiment of the present utility model, a ball seat 23 capable of receiving a pressure-holding ball 5 for pressure-holding operation is provided at an upper end of a center pipe 2. Through setting up of ball seat 23 for when needs carry out the pressurization operation to downhole fishing tool 100 so that piston 31 slides, the staff can conveniently put into behind the ball 5 that presses is suppressed in the well head, pumps the drilling fluid of certain pressure again just can go on, easy operation is convenient, and the reliability is high, provides the condition for follow-up operation can develop smoothly.

Preferably, the pressure-building ball 5 is a soluble pressure-building ball. Through this kind of design for hold back pressure ball 5 can dissolve by oneself after accomplishing the task of holding back pressure, avoided the follow-up step of taking out to hold back pressure ball 5, improved the efficiency of work in the pit.

As shown in fig. 1, in one embodiment of the present utility model, a liquid inlet 24 is provided in the center tube 2. The liquid inlet 24 facilitates liquid to enter the space between the central tube 2 and the cylinder sleeve 1 to apply pressure to the piston 31, so that the piston 31 is pushed to slide. By this design, the pressurization process of the piston 31 is simply and conveniently accomplished, providing a structural basis for the successful operation of the subsequent downhole fishing tool 100.

Preferably, in order to increase the efficiency of the utilization of the downhole pressure and reduce unnecessary pressure losses, the inlet 24 is provided on the central tube 2 at a position above the piston 31.

Preferably, the size of the aperture of the inlet 22 is in the range of 0.5-2mm for ease of processing and pressure control purposes.

As shown in fig. 1, in one embodiment of the utility model, a first sealing ring 312 is provided between the piston 31 and the cylinder liner 1. Through the design, the gap between the piston 31 and the cylinder sleeve 1 is sealed, so that the drilling fluid entering the space between the cylinder sleeve 1 and the central tube 2 through the fluid inlet 24 cannot flow out through the gap between the cylinder sleeve 1 and the piston 31, the pressure exerted by the drilling fluid is ensured to act on the piston 31 as much as possible, and the utilization rate of the pressure is improved.

As shown in fig. 1, in one embodiment of the utility model, a second sealing ring 25 is provided between the center tube 2 and the piston 31. Through the design, the gap between the central pipe 2 and the piston 31 is sealed, so that the drilling fluid entering the space between the cylinder sleeve 1 and the central pipe 2 through the fluid inlet 24 cannot flow out through the gap between the central pipe 2 and the piston 31, the pressure exerted by the drilling fluid is ensured to act on the piston 31 as much as possible, and the utilization rate of the pressure is improved.

As shown in fig. 1, in one embodiment of the utility model, the fishing mechanism 32 is a plurality of resilient fingers 320 connected below the piston 31 and distributed along the circumference of the piston 31. The elastic claw 320 includes a connecting rod 3201 connected with the piston 31, and a projection 3202 connected to a lower end of the connecting rod 3201 and having a projection directed outward in a radial direction. Through this design, utilize elastic claw 320 on the whole have high elasticity, the characteristics of easily warping to and the protruding of being convenient for carry out joint and lift to fish 4 of bulge 3202, realized the fishing operation to fish 4 high-efficiently, swiftly.

Preferably, the number of the elastic claws 320 is set to not less than 3.

Preferably, the elastic claws 320 are uniformly distributed in the circumferential direction of the piston 31.

As shown in fig. 1, in one embodiment of the utility model, an upper joint 6 is provided at a position between the central tube 2 and the cylinder liner 1. Through this design, the downhole fishing tool 100 is facilitated to be connected with the coiled tubing, thereby facilitating the running and lifting operations of the downhole fishing tool 100 by the staff.

In one embodiment of the utility model, as shown in fig. 1, a third sealing ring 26 is provided between the central tube 2 and the upper joint 6. Through the design, the gap between the central tube 2 and the upper joint 6 is sealed, so that the drilling fluid entering the space between the cylinder sleeve 1 and the central tube 2 through the fluid inlet 24 cannot flow out through the gap between the central tube 2 and the upper joint 6, the pressure exerted by the drilling fluid is ensured to act on the piston 31 as much as possible, and the utilization rate of the pressure is improved.

As shown in fig. 1, in one embodiment of the utility model, a fourth sealing ring 61 is provided between the cylinder liner 1 and the upper joint 6. Through the design, the gap between the cylinder sleeve 1 and the upper joint 6 is sealed, so that the drilling fluid entering the space between the cylinder sleeve 1 and the upper joint 6 through the fluid inlet 24 cannot flow out through the gap between the cylinder sleeve 1 and the upper joint 6, the pressure exerted by the drilling fluid is ensured to act on the piston 31 as much as possible, and the utilization rate of the pressure is improved.

In one embodiment of the utility model, a threaded connection exists between the outside of the lower end of the upper joint 6 and the cylinder sleeve 1, and a threaded connection exists between the upper end of the upper joint 6 and the continuous oil pipe.

In one embodiment of the utility model, there is a threaded connection between the inner side of the middle of the upper joint 6 and the central tube 2.

The downhole fishing tool 100 has the advantages of simple structure, low manufacturing cost, convenient operation and high working efficiency and operation safety, and is particularly suitable for fishing the fish with the hollow cylindrical structure.

In the present application, the specific meaning of "upper", "lower", "inner", "outer", "middle", "side", etc. when referring to azimuth terms is referred to the drawing state of the downhole fishing tool 100 in fig. 1.

Finally, it is to be noted that while the utility model has been described in detail with reference to preferred embodiments, various modifications can be made and equivalents can be substituted for elements thereof without departing from the scope of the utility model. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as long as there is no structural conflict. It is intended that the utility model not be limited to the particular embodiments disclosed herein, but that the utility model will include all embodiments falling within the scope of the appended claims.

Claims

1. A downhole fishing tool, comprising:

a cylinder sleeve (1) which is constructed as a hollow tubular structure;

A central tube (2) at least partially disposed inside the cylinder liner (1), comprising a tube body (21) and a cone (22) disposed below the tube body (21), the cone (22) comprising an expansion portion (221) configured to have an outer contour gradually extending from the middle to the periphery in a top-to-bottom direction, and a guide portion (222) connected below the expansion portion (221) and configured such that at least a portion of the outer contour is not smaller than a maximum radial dimension of the cylinder liner (1); and

The working part (3) comprises a piston (31) sleeved between the cylinder sleeve (1) and the central tube (2), and a salvaging mechanism (32) connected to the lower end of the piston (31), wherein the piston (31) is fixedly connected with the cylinder sleeve (1),

Wherein the piston (31) is configured to separate from the cylinder sleeve (1) and drive the fishing mechanism (32) to slide downwards in response to the increase of pressure, and the fishing mechanism (32) is configured to expand radially in response to the change of the profile of the cone (22) in the sliding process, so that the fishing mechanism (32) can fish the fish (4) out of the well.

2. The downhole fishing tool of claim 1, wherein: the cylinder sleeve (1) is provided with a groove (11) corresponding to the C-shaped clamp spring (311), the C-shaped clamp spring (311) is arranged at the outer wall of the piston (31), and when the C-shaped clamp spring (311) slides to the groove (11) in the sliding process, the pre-tightened C-shaped clamp spring (311) is sprung out and embedded into the groove (11) to terminate the sliding.

3. The downhole fishing tool of claim 2, wherein: the upper end of the central tube (2) is provided with a ball seat (23) which can hold the pressure-holding ball (5) for pressure holding operation.

4. A downhole fishing tool according to claim 3, wherein: a liquid inlet (24) is arranged on the central tube (2) for facilitating liquid to enter so as to apply pressure to the piston (31).

5. The downhole fishing tool of claim 4, wherein: the salvaging mechanism (32) is a plurality of elastic claws (320) distributed along the circumferential direction of the piston (31).

6. The downhole fishing tool according to any of claims 1 to 5 wherein: a first sealing ring (312) is arranged between the cylinder sleeve (1) and the piston (31).

7. The downhole fishing tool of claim 6, wherein: a second sealing ring (25) is arranged between the central tube (2) and the piston (31).

8. The downhole fishing tool according to any of claims 1 to 5 wherein: an upper joint (6) is arranged at a position between the central tube (2) and the cylinder sleeve (1).

9. The downhole fishing tool of claim 8, wherein: a third sealing ring (26) is arranged between the central tube (2) and the upper joint (6).

10. The downhole fishing tool of claim 9, wherein: a fourth sealing ring (61) is arranged between the cylinder sleeve (1) and the upper joint (6).