A sealed back-off overshot

Abstract

The utility model discloses a kind of inverted buckle fishing tube with seal, belong to petroleum exploitation technical field.The inverted buckle fishing tube includes upper joint, slip assembly and leading shoe, the upper end of the slip assembly is connected with the lower end of upper joint, the upper end of the leading shoe is connected with the lower end of slip assembly by the sealing assembly of a plurality of head-to-tail connection.The sealing assembly and slip assembly are independently set respectively, and the modularization design is carried out to sealing assembly, before using inverted buckle fishing tube, the quantity of sealing assembly in inverted buckle fishing tube can be increased or reduced according to the weight of fractured oil pipe and sealing requirement etc., to adjust the sealing performance and sealing reliability of inverted buckle fishing tube to fractured oil pipe outer wall, the practicability and use flexibility of inverted buckle fishing tube are significantly improved.

Description

Technical Field

[0001] This utility model relates to a sealed inverted scooping tube, belonging to the field of petroleum extraction technology. Background Technology

[0002] Oil extraction refers to the process of extracting crude oil from underground reservoirs and is one of the core links in the petroleum industry. During oil extraction, tubing is a crucial channel connecting the downhole reservoir to the surface production system. However, as oil extraction progresses into its later stages, accidents such as tubing wear-through or breakage frequently occur, severely impacting extraction efficiency and increasing costs. Therefore, manual intervention is needed to quickly restore the tubing to its function as an oil transport channel. One common practice is to reconnect the tubing that has fallen to the bottom of the well to restore its function. Before reconnecting the tubing, a retrieval device must be used to remove the broken tubing from the well. However, during the removal of the broken tubing, high-pressure fluids inside the well may spray out along the outer wall of the broken tubing, leading to well control risks such as blowouts. Leaked oil, gas, or chemicals may pollute the surface environment and even cause fires or explosions. Therefore, the outer wall of the broken tubing must be sealed before removing it from the well.

[0003] Chinese patent document CN116241206A discloses a fishing device. The device has a sealing assembly on the inner wall of the fishing tube, so that the inner wall of the sealing assembly and the outer wall of the fish dropper are sealed by a second sealing element in the sealing assembly, namely a Y-shaped sealing packing.

[0004] However, when using this device to remove the ruptured tubing from the well, the structural limitation that both the slips and the sealing assembly are installed inside the cylindrical body means that the sealing performance and reliability of the device cannot be adjusted according to the weight of the ruptured tubing and sealing requirements. Utility Model Content

[0005] To solve the above-mentioned technical problems, this utility model provides a sealed inverted scooping cylinder.

[0006] This utility model is achieved through the following technical solution:

[0007] A sealed inverted scooping tube includes an upper connector, a slip assembly, and a guide shoe. The upper end of the slip assembly is connected to the lower end of the upper connector, and the upper end of the guide shoe is connected to the lower end of the slip assembly through a plurality of sealing assemblies connected end to end.

[0008] The slip assembly includes a cylinder and, from top to bottom, a tubing limiting ring, a slip limiting ring, a slip, a slip sleeve, and a lead sleeve, all arranged sequentially within the cylinder. The radial degrees of freedom of the tubing limiting ring, slip limiting ring, slip, slip sleeve, and lead sleeve are all limited by the inner wall of the cylinder. The upper end of the cylinder is threadedly connected to the lower end of the upper connector. The axial degree of freedom of the tubing limiting ring is limited by the upper connector and the slip limiting ring. The axial degree of freedom of the slip limiting ring is limited by the tubing limiting ring and a step within the cylinder. The slip moves between the slip limiting ring and the lead sleeve. The slip sleeve is fixed within the cylinder. The axial degree of freedom of the lead sleeve is limited by the slip sleeve and a sealing assembly near the slip assembly.

[0009] The inner diameter of the tubing limiting ring is smaller than the inner diameter of the slip limiting ring.

[0010] The slip is a conical slip, and the slip sleeve has a conical hole or a circular hole along the axial direction.

[0011] The lower end of the inner hole of the sleeve is chamfered.

[0012] The sealing assembly includes a packing outer cylinder and a packing inner cylinder. The upper end of the packing outer cylinder is threadedly connected to the lower end of the slip assembly or the lower end of the previous sealing assembly. The lower end of the packing outer cylinder is threadedly connected to the upper end of the next sealing assembly or the upper end of the guide shoe. The packing inner cylinder is located inside the packing outer cylinder. The radial degree of freedom of the packing inner cylinder is limited by the inner wall of the packing outer cylinder, and the axial degree of freedom is limited by the internal step of the packing outer cylinder and the upper end of the next sealing assembly or the upper end of the guide shoe. Multiple packing components are provided inside the packing inner cylinder.

[0013] The inner cylinder of the packing system contains two packing assemblies.

[0014] The inner wall of the packing inner cylinder is provided with an annular groove along the circumference at a position corresponding to the packing assembly. The packing assembly includes two packing gaskets and multiple V-shaped sealing packings located in the annular groove. All V-shaped sealing packings are located between two packing gaskets, and the V-shaped opening of the V-shaped sealing packings faces upward.

[0015] The beneficial effects of this utility model are as follows: the sealing assembly and the slip assembly are set up independently, and the sealing assembly is modularly designed. Before using the inverted retrieval cylinder, the number of sealing assemblies in the inverted retrieval cylinder can be increased or decreased according to the weight of the broken oil pipe and the sealing requirements, so as to adjust the sealing performance and sealing reliability of the inverted retrieval cylinder to the outer wall of the broken oil pipe, which significantly improves the practicality and flexibility of the inverted retrieval cylinder. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model;

[0017] Figure 2 for Figure 1A magnified view of a portion at point A.

[0018] In the diagram: 1-Upper connector, 2-Slip assembly, 20-Cylinder body, 21-Oil pipe limiting ring, 22-Slip limiting ring, 23-Slip, 24-Slip sleeve, 25-Guide sleeve, 3-Sealing assembly, 30-Packing outer cylinder, 31-Packing inner cylinder, 32-Packing gasket ring, 33-V-type sealing packing, 4-Guide shoe. Detailed Implementation

[0019] The technical solution of this utility model is further described below, but the scope of protection is not limited to what is described.

[0020] like Figure 1 and Figure 2 As shown, the inverted retrieval cylinder with a seal according to this utility model includes an upper connector 1, a slip assembly 2, and a guide shoe 4. The upper end of the slip assembly 2 is connected to the lower end of the upper connector 1, and the upper end of the guide shoe 4 is connected to the lower end of the slip assembly 2 through multiple sealing assemblies 3 connected end to end. The sealing assembly 3 and the slip assembly 2 are set independently, and the sealing assembly 3 is modularly designed. Before using the inverted retrieval cylinder, the number of sealing assemblies 3 in the inverted retrieval cylinder can be increased or decreased according to the weight of the broken oil pipe and sealing requirements, so as to adjust the sealing performance and sealing reliability of the inverted retrieval cylinder to the outer wall of the broken oil pipe, significantly improving the practicality and flexibility of the inverted retrieval cylinder.

[0021] The slip assembly 2 includes a cylinder 20 and, from top to bottom, a tubing limiting ring 21, a slip limiting ring 22, a slip 23, a slip sleeve 24, and a lead sleeve 25, all arranged sequentially within the cylinder 20. The radial degrees of freedom of the tubing limiting ring 21, slip limiting ring 22, slip 23, slip sleeve 24, and lead sleeve 25 are all limited by the inner wall of the cylinder 20. The upper end of the cylinder 20 is threadedly connected to the lower end of the upper connector 1. The axial degree of freedom of the tubing limiting ring 21 is limited by the upper connector 1 and the slip limiting ring 22. The axial degree of freedom of the slip limiting ring 22 is limited by the tubing limiting ring 21 and the step inside the cylinder 20. The slip 23 moves between the slip limiting ring 22 and the lead sleeve 25. The slip sleeve 24 is fixed inside the cylinder 20. The axial degree of freedom of the lead sleeve 25 is limited by the slip sleeve 24 and the sealing assembly 3 near the slip assembly 2.

[0022] The inner diameter of the tubing limiting ring 21 is smaller than the inner diameter of the slip limiting ring 22. When the upper end of the broken tubing is inserted into the inverted retrieval cylinder, the upper end of the broken tubing is limited by the tubing limiting ring 21.

[0023] The slip 23 is a conical slip, and the slip sleeve 24 has a conical or circular hole along the axial direction. When the inverted retrieval cylinder is pressed down and rotated, the upper end of the broken tubing enters the inverted retrieval cylinder under the guidance of the guide shoe 4. The inner teeth of the conical slip contact the outer wall of the broken tubing. When the inverted retrieval cylinder is slowly lifted, the conical slip moves downward relative to the inverted retrieval cylinder under its own weight and the gravity of the broken tubing. The lower end of the conical slip enters the conical or circular hole on the slip sleeve 24. Under the squeezing action of the conical or circular hole, the conical slip contracts radially inward to completely bite the broken tubing, so that the broken tubing can be reliably removed from the well through the inverted retrieval cylinder.

[0024] The lower end of the inner hole of the sleeve 25 is chamfered to facilitate the introduction of the upper end of the broken oil pipe into the slip 23.

[0025] The sealing assembly 3 includes a packing outer cylinder 30 and a packing inner cylinder 31. The upper end of the packing outer cylinder 30 is threadedly connected to the lower end of the slip assembly 2 or the lower end of the previous sealing assembly 3. The lower end of the packing outer cylinder 30 is threadedly connected to the upper end of the next sealing assembly 3 or the upper end of the guide shoe 4. The packing inner cylinder 31 is disposed inside the packing outer cylinder 30. The radial degree of freedom of the packing inner cylinder 31 is limited by the inner wall of the packing outer cylinder 30, and the axial degree of freedom is limited by the internal step of the packing outer cylinder 30 and the upper end of the next sealing assembly 3 or the upper end of the guide shoe 4. Multiple packing components are disposed inside the packing inner cylinder 31.

[0026] The inner packing cylinder 31 is equipped with two packing assemblies.

[0027] The inner wall of the packing inner cylinder 31 has an annular groove circumferentially formed at a position corresponding to the packing assembly. The packing assembly includes two packing rings 32 and multiple V-shaped sealing packings 33 located within the annular groove. All V-shaped sealing packings 33 are located between two packing rings 32, with the V-shaped opening of the V-shaped sealing packings 33 facing upwards. When the inverted retrieval cylinder is pressed down and rotated, the upper end of the broken oil pipe enters the inverted retrieval cylinder under the guidance of the guide shoe 4. The inner edge of the V-shaped sealing packing 33 contacts the outer wall of the broken oil pipe. When the inverted retrieval cylinder is slowly lifted, the broken oil pipe moves downwards a certain distance relative to the inverted retrieval cylinder. During this process, the inner edge of the V-shaped sealing packing 33 will open inwards under the action of the friction force applied by the broken oil pipe, thereby increasing the friction force between the V-shaped sealing packing 33 and the broken oil pipe and achieving a reliable seal on the outer wall of the broken oil pipe. V-type sealing packing 33 is made of fluororubber, with the standard grade being FKM, and is resistant to temperatures from -20℃ to 200℃.

[0028] The working principle or usage process of the sealed inverted scooping tube of this utility model is as follows:

[0029] The inverted retrieval cylinder is slowly lowered to the broken tubing at the bottom of the well. Then, external force is used to drive the inverted retrieval cylinder to rotate slowly relative to the broken tubing. Next, the inverted retrieval cylinder is slowly pressed down, and the upper end of the broken tubing is introduced into the inverted retrieval cylinder using the guide shoe 4. When the upper end of the broken tubing contacts the lower end of the tubing limiting ring 21, the broken tubing cannot continue to move upward relative to the inverted retrieval cylinder. At this time, the outer wall of the broken tubing contacts the inner teeth of the slip 23, and the slip 23 moves upward with the broken tubing under the action of the friction force applied by the broken tubing until its upper end face contacts the lower end face of the slip limiting ring 22. At the same time, the outer wall of the broken tubing keeps in contact with the inner edge of the V-shaped sealing packing 33. Next, the broken tubing is slowly lifted by the inverted retrieval cylinder. Under the action of gravity, the broken tubing and slip 23 move downward together relative to the inverted retrieval cylinder until the lower end of slip 23 enters the inner hole of slip sleeve 24. Under the squeezing action of slip sleeve 24, slip 23 contracts radially inward to completely bite the broken tubing. Thus, the broken tubing can be reliably removed from the well by the inverted retrieval cylinder. During the downward movement of the broken tubing relative to the inverted retrieval cylinder, the inner edge of the V-shaped sealing packing 33 will open inward under the action of the friction force applied by the broken tubing, thereby increasing the friction force between the V-shaped sealing packing 33 and the broken tubing and achieving a reliable seal on the outer wall of the broken tubing.

[0030] When it is necessary to disconnect the broken tubing, simply press down and rotate the inverted retrieval cylinder. At this time, only a small amount of force is needed to lift the inverted retrieval cylinder to the wellhead.

Claims

1. A sealed inverted scooping tube, characterized in that: It includes an upper connector (1), a slip assembly (2) and a guide shoe (4). The upper end of the slip assembly (2) is connected to the lower end of the upper connector (1), and the upper end of the guide shoe (4) is connected to the lower end of the slip assembly (2) through several sealing assemblies (3) connected end to end in sequence.

2. The sealed inverted scooping cylinder as described in claim 1, characterized in that: The slip assembly (2) includes a cylinder (20) and, from top to bottom, a tubing limiting ring (21), a slip limiting ring (22), a slip (23), a slip sleeve (24), and a lead sleeve (25) arranged inside the cylinder (20). The radial degrees of freedom of the tubing limiting ring (21), slip limiting ring (22), slip (23), slip sleeve (24), and lead sleeve (25) are all limited by the inner wall of the cylinder (20). The upper end of the cylinder (20) is threadedly connected to the lower end of the upper connector (1). The axial degree of freedom of the positioning ring (21) is limited by the upper connector (1) and the slip limiting ring (22). The axial degree of freedom of the slip limiting ring (22) is limited by the oil pipe limiting ring (21) and the step inside the cylinder (20). The slip (23) moves between the slip limiting ring (22) and the lead sleeve (25). The slip sleeve (24) is fixed inside the cylinder (20). The axial degree of freedom of the lead sleeve (25) is limited by the slip sleeve (24) and the sealing assembly (3) near the slip assembly (2).

3. The sealed inverted scooping cylinder as described in claim 2, characterized in that: The inner diameter of the tubing limiting ring (21) is smaller than the inner diameter of the slip limiting ring (22).

4. The sealed inverted scooping cylinder as described in claim 2, characterized in that: The slip (23) is a conical slip, and the slip sleeve (24) has a conical hole or a circular hole along the axial direction.

5. The sealed inverted scooping cylinder as described in claim 2, characterized in that: The lower end of the inner hole of the lead sleeve (25) is chamfered.

6. The sealed inverted scooping cylinder as described in claim 1, characterized in that: The sealing assembly (3) includes a packing outer cylinder (30) and a packing inner cylinder (31). The upper end of the packing outer cylinder (30) is threadedly connected to the lower end of the slip assembly (2) or the lower end of the previous sealing assembly (3). The lower end of the packing outer cylinder (30) is threadedly connected to the upper end of the next sealing assembly (3) or the upper end of the guide shoe (4). The packing inner cylinder (31) is located inside the packing outer cylinder (30). The radial degree of freedom of the packing inner cylinder (31) is limited by the inner wall of the packing outer cylinder (30). The axial degree of freedom is limited by the internal steps of the packing outer cylinder (30) and the upper end of the next sealing assembly (3) or the upper end of the guide shoe (4). Multiple packing components are provided inside the packing inner cylinder (31).

7. The sealed inverted scooping cylinder as described in claim 6, characterized in that: The inner packing cylinder (31) contains two packing components.

8. The sealed inverted scooping cylinder as described in claim 6 or 7, characterized in that: The inner wall of the packing inner cylinder (31) is provided with an annular groove along the circumferential direction at a position corresponding to the packing assembly. The packing assembly includes two packing gaskets (32) located in the annular groove and multiple V-shaped sealing packings (33). All V-shaped sealing packings (33) are located between the two packing gaskets (32), and the V-shaped opening of the V-shaped sealing packings (33) faces upward.

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