Wellhead tubing connection device and seal verification tool

Abstract

The application relates to a wellhead oil pipe connecting device and a sealing inspection tool, wherein the wellhead oil pipe connecting device comprises an outer cylinder, an installation hole extending along the length direction of the outer cylinder and penetrating through the outer cylinder is arranged in the outer cylinder; an upper structure, a first grabbing structure, a first sealing structure and a first limiting structure are sequentially arranged in the installation hole from top to bottom, the first sealing structure and the first limiting structure are both provided with a matching channel extending from the upper end to the lower end, the matching channel is used for inserting the oil pipe, the upper structure is provided with a connecting channel used for sealing and fixedly connecting with the sealing inspection tool in the oil pipe, the connecting channel is communicated with the matching channel; the first grabbing structure can be connected with the oil pipe and can be moved downward under the action of the upper structure; the first sealing structure can seal the annulus between the outer cylinder and the oil pipe under the action of the first grabbing structure; and the first limiting structure is fixedly connected with the outer cylinder. The wellhead oil pipe connecting device can be sealingly connected with the oil pipe in the wellhead oil pipe connecting device.

Description

Technical Field

[0001] This invention belongs to the field of stuck tubing treatment technology, specifically relating to a wellhead tubing connection device and a sealing inspection tool. Background Technology

[0002] During well workover and tripping operations, there is a chance that the tubing string may suddenly become stuck, preventing it from being pulled up or down. A more challenging situation arises when the lower coupling of the stuck tubing is located directly below the rotary table, making the upper coupling too high and hindering tubing removal. Furthermore, for stuck tubing with its lower coupling directly below the rotary table and without a circulation line installed, the stuck tubing may remain unresolved for an extended period, increasing well control risks. Currently, the primary method used during workover is to cut the tubing to address these issues. However, while conventional tubing reels can be connected to the cut tubing, they lack the ability to seal the tubing, thus failing to achieve the goals of sealing the well and controlling wellbore pressure overflow. Summary of the Invention

[0003] In order to solve all or part of the above problems, the present invention aims to provide a wellhead tubing connection device and a sealing inspection tool. The wellhead tubing connection device can be sealed to the tubing inside it, and the sealing inspection tool can be sealed to the tubing outside it, thereby sealing the tubing channel or the annulus outside the tubing.

[0004] According to one aspect of the present invention, a wellhead tubing connection device is provided, comprising an outer cylinder, wherein an installation hole is provided inside the outer cylinder, extending along the length direction of the outer cylinder and penetrating the outer cylinder;

[0005] The mounting hole is provided with, from top to bottom, an upper structure, a first gripping structure, a first sealing structure, and a first limiting structure. Both the first sealing structure and the first limiting structure have mating channels extending from the upper end to the lower end, which are used for inserting an oil pipe. The upper structure has a connecting channel for sealing and fixing with a sealing inspection tool inside the oil pipe, and the connecting channel communicates with the mating channel.

[0006] The first gripping structure can be connected to the oil pipe and can move downward under the action of the upper structure; the first sealing structure can seal the annulus between the outer cylinder and the oil pipe under the action of the first gripping structure; the first limiting structure is fixedly connected to the outer cylinder;

[0007] A second sealing structure is provided between the upper structure and the outer cylinder. The second sealing structure is fixedly and sealed to the outer cylinder and to the upper structure. The upper structure is movable relative to the second sealing structure, and the second sealing structure is fixed to the upper structure.

[0008] Furthermore, the first gripping structure includes an upper slip and a lower slip. The lower part of the upper slip is provided with several keyways extending through the lower end of the upper slip. Several connecting keys are fixedly connected inside the outer cylinder. The connecting keys mate with the corresponding keyways and are aligned along the extension direction of the mounting hole. The depth of the keyway is greater than the length of the connecting key. The lower end of the upper slip coincides with the lower end of the connecting key. The lower slip is connected inside the upper slip and is provided with a through threaded hole. The inner diameter of the threaded hole is smaller than the outer diameter of the oil pipe. The first sealing structure is located below the connecting key.

[0009] Furthermore, the lower clamp is an elastic element, and there is a relative displacement between the upper clamp and the lower clamp along the axial direction of the mounting hole. When the upper clamp moves upward relative to the lower clamp, the inner diameter of the lower clamp decreases.

[0010] Furthermore, the upper structure includes an upper connector and a central tube. The upper connector has a connecting channel inside. The upper connector is threaded to the upper end of the central tube. The central tube has a through hole that connects the connecting channel and the mating channel.

[0011] The second sealing structure includes a sealing sleeve fitted on the central tube, the sealing sleeve being threadedly connected to the central tube, the central tube moving downward along the axial direction of the mounting hole can push the upper slip downward, the sealing sleeve being fixedly connected to the outer cylinder, and sealing elements being provided between the central tube and the sealing sleeve, and between the sealing sleeve and the outer cylinder.

[0012] Furthermore, a bearing is fitted at the lower end of the central tube, the upper end of the bearing is limited by a central tube convex ring, and the lower end of the bearing is limited by a bearing sleeve. A pressure cap is provided between the central tube convex ring and the sealing sleeve, and the pressure cap is threadedly connected to the bearing sleeve. The central tube pushes the upper slip through the bearing sleeve. A bushing is fitted on the outside of the bearing sleeve, and the bushing extends to fit on the pressure cap. The bushing blocks the bottom of the sealing sleeve.

[0013] Furthermore, the upper end of the outer cylinder is provided with an anti-rotation structure, which cooperates with the outer cylinder to fix the outer cylinder by fixing the anti-rotation structure, and the anti-rotation structure is fixedly connected to the sealing sleeve.

[0014] Furthermore, the anti-rotation structure includes an anti-rotation ring and a back cap. The lower end of the anti-rotation ring is provided with a plurality of insert teeth, and a slot is formed between two adjacent insert teeth. The upper end of the outer cylinder is provided with a groove that mates with the insert teeth, and the upper end of the outer cylinder is provided with a protrusion that mates with the slot. The anti-rotation ring and the outer cylinder are connected by the insert teeth and the groove, and the slot and the protrusion. The anti-rotation ring is fitted on the sealing sleeve. The back cap is located on the side of the anti-rotation ring away from the outer cylinder, and the back cap is threadedly connected to the sealing sleeve.

[0015] Furthermore, the sealing sleeve includes a first sealing sleeve section and a second sealing sleeve section. The outer diameter of the first sealing sleeve section is smaller than the outer diameter of the second sealing sleeve section. The second sealing sleeve section is threadedly connected to the outer cylinder. The anti-rotation ring is fitted on the first sealing sleeve section. The back cap is threadedly connected to the first sealing sleeve section. A first screw is connected between the central tube and the sealing sleeve.

[0016] Furthermore, the first sealing structure includes a sealing cylinder with an internal mating channel. The upper end of the sealing cylinder contacts the lower end of the first gripping structure, and the lower end of the sealing cylinder contacts the first limiting structure. The sealing cylinder can deform under the action of the first gripping structure to seal the annulus between the outer cylinder and the oil pipe. Furthermore, a pressure pad is provided above the sealing cylinder, and a support pad is provided below the sealing cylinder.

[0017] Furthermore, the first limiting structure includes a connecting sleeve that is threadedly connected to the outer cylinder, the connecting sleeve having a mating channel inside, and the upper end of the connecting sleeve contacting the first sealing structure; the first limiting structure is connected to a second gripping structure, the second gripping structure being used to connect to the oil pipe.

[0018] Furthermore, the second gripping structure includes a guide shoe, which is located inside the connecting sleeve and is threadedly connected to the connecting sleeve; a second screw is connected between the connecting sleeve and the guide shoe, and the width of the screw hole on the guide shoe that mates with the second screw is greater than the diameter of the second screw along the axial direction of the mounting hole; a slip ring composed of several slip fan rings is provided between the connecting sleeve and the guide shoe, with a gap between two adjacent slip fan rings, and each slip fan ring mates with the inclined surface on the guide shoe, and the maximum inner diameter of the slip ring composed of several slip fan rings is smaller than the outer diameter of the oil pipe.

[0019] According to a second aspect of the present invention, a sealing inspection tool is provided, the sealing inspection tool including a central rod, a connecting member sleeved on the upper part of the central rod, the connecting member being movable along the length direction of the central rod, and the connecting member being fixed on the central rod;

[0020] The connector is provided with a mating structure that is sealed to the connection channel of the wellhead tubing connection device; the connector is provided with a pressure port and a pressure outlet, the pressure port is connected to the pressure outlet, the pressure port is located above the mating structure, and the pressure outlet is located below the mating structure;

[0021] The lower part of the central rod is fitted with a third sealing structure. When the third sealing structure is subjected to the force of the connecting member, its outer diameter can increase to seal and connect with the oil pipe outside it. The lower end of the central rod is fixedly connected with a second limiting structure, which is used to limit the third sealing structure.

[0022] Furthermore, the mating structure is an external thread structure, and the connecting channel is a threaded hole that mates with the external thread structure; the connecting member is threadedly connected to the center rod, and two sets of sealing members are provided between the connecting member and the center rod, one set of sealing members being located above the pressure port, and the other set of sealing members being located below the pressure outlet.

[0023] Furthermore, the third sealing structure is a sealing rubber tube, which is sleeved on the connector. The connector is provided with a retaining ring, which is located above the sealing rubber tube. The outer diameter of the retaining ring is larger than the inner diameter of the sealing rubber tube.

[0024] Furthermore, the second limiting structure includes a limiting block, which is threadedly connected to the center rod. A mating block is provided between the limiting block and the sealing rubber cylinder. The lower end of the mating block contacts the limiting block, and the upper end of the mating block contacts the sealing rubber cylinder. The mating block presses against the sealing rubber cylinder.

[0025] As can be seen from the above technical solution, the wellhead tubing connection device and sealing inspection tool provided by the present invention have the following beneficial effects:

[0026] The wellhead tubing connection device and sealing inspection tool of the present invention can both be connected to the cut tubing. The wellhead tubing connection device can grip the tubing and seal the annulus between the connection device and the tubing. The sealing inspection tool can be inserted into the tubing to seal the channel inside the tubing. Furthermore, the sealing inspection tool can also inspect whether there is a seal between the connection device and the tubing, as well as inside the tubing. Thus, the purpose of sealing the well and controlling the overflow of wellbore pressure can be achieved. Attached Figure Description

[0027] Figure 1 This is a cross-sectional view of a wellhead tubing connection device according to an embodiment of the present invention;

[0028] Figure 2A schematic diagram showing the connection between the wellhead tubing connection device and the sealing inspection tool and the tubing;

[0029] Figure 3 This is a cross-sectional view of the sealing inspection tool according to an embodiment of the present invention;

[0030] The attached figures are labeled as follows: upper connector 1, connecting channel 101, upper connector protruding ring 102, central tube 2, central tube protruding ring 201, first screw 3, back cap 4, anti-rotation ring 5, insert tooth 51, sealing sleeve 6, pressure cap 7, bushing 8, bearing 9, bearing sleeve 10, outer cylinder 11, protrusion 1101, connecting key 1102, upper slip 12, lower slip 13, pressure pad 14, sealing cylinder 15, support pad 16, connecting sleeve 17, slip ring 18, second screw 19, guide shoe 20;

[0031] Wellhead tubing connection device 01, tubing 02, sealing inspection tool 03;

[0032] Center rod 031, connector 032, pressure port 0321, mating structure 0322, pressure outlet 0323, sealing tube 033, limit block 034, mating block 035. Detailed Implementation

[0033] To better understand the purpose, structure, and function of this invention, the following detailed description of a wellhead tubing connection device and sealing inspection tool of this invention is provided in conjunction with the accompanying drawings.

[0034] like Figures 1-2 As shown, this invention illustrates a wellhead tubing connection device, including an outer cylinder 11. An installation hole is provided inside the outer cylinder 11, extending along the length of the outer cylinder 11 and penetrating the outer cylinder 11. The installation hole inside the outer cylinder 11 is used to install an upper structure, a first gripping structure, a first sealing structure, and a first limiting structure. Specifically, the upper structure, the first gripping structure, the first sealing structure, and the first limiting structure are arranged sequentially from top to bottom inside the installation hole.

[0035] A second sealing structure is provided between the upper structure and the outer cylinder 11. The second sealing structure is fixedly and sealingly connected to the outer cylinder 11 and to the upper structure. The upper structure can move relative to the second sealing structure, and the second sealing structure can be fixed to the upper structure. The second sealing structure achieves a seal between the outer cylinder 11 and the upper structure. The upper structure can move relative to the second sealing structure and the outer cylinder 11 along the axis of the mounting hole. After moving to a certain position, the upper structure can be fixed to the second sealing structure. This arrangement allows the upper structure to move relative to the second sealing structure and the outer cylinder 11 in the direction of the axis of the mounting hole, and after moving to a certain position, it can be fixed at that position by fixing it to the second sealing structure. Furthermore, the second sealing structure prevents leakage between the outer cylinder 11 and the upper structure.

[0036] Furthermore, both the first sealing structure and the first limiting structure are provided with a mating channel extending from the upper end to the lower end. The mating channel is used for the insertion of the tubing 02. Specifically, the wellhead tubing connection device 01 is fitted onto the cut tubing 02, and pressing down the wellhead tubing connection device 01 will insert the tubing 02 into the mating channel. The first gripping structure can connect with the tubing 02. In addition, the first gripping structure can also move downward under the action of the upper structure, thereby transmitting the force of the upper structure to the first sealing structure. The first sealing structure can seal the annulus between the outer cylinder 11 and the tubing 02 under the action of the first gripping structure. The first limiting structure is fixedly connected to the outer cylinder 11. The first limiting structure is used to limit the first sealing structure to prevent the first sealing structure from falling off from the lower end of the outer cylinder 11.

[0037] Specifically, the connection between the wellhead tubing connection device 01 and its internal tubing 02 is achieved through the first gripping structure, and the seal between the wellhead tubing connection device 01 and its internal tubing 02 is achieved through the first sealing device.

[0038] Finally, the upper structure is provided with a connecting channel 101, which is used for sealing and fixing with the sealing inspection tool inside the oil pipe 02. The connecting channel 101 communicates with the mating channel. Specifically, the upper structure is provided with a connecting channel 101 for connecting the sealing inspection tool, so that the sealing inspection tool can be connected through the connecting channel 101.

[0039] To reiterate: In practical use, first, the wellhead tubing connection device 01 is fitted onto the cut tubing 02. Then, pressing down the wellhead tubing connection device 01 inserts the tubing 02 into the mating channel. The first gripping structure enables connection with the tubing 02. After the wellhead tubing connection device 01 is connected to the tubing 02, the upper structure is lowered. The upper structure, through the first gripping structure, seals the annulus between the outer cylinder 11 and the tubing 02, thus achieving a sealed connection between the wellhead tubing connection device 01 and the tubing 02. Furthermore, the wellhead tubing connection device 01 can also be connected to a sealing inspection tool via the connection channel 101, thereby improving the sealing of the annulus within the tubing 02 by the sealing inspection tool.

[0040] In one embodiment, the first gripping structure includes an upper slip 12 and a lower slip 13. The lower part of the upper slip 12 is provided with a plurality of keyways extending through the lower end of the upper slip 12. A plurality of connecting keys 1102 are fixedly connected inside the outer cylinder 11. The connecting keys 1102 mate with the corresponding keyways. Along the extension direction of the mounting hole, the depth of the keyway is greater than the length of the connecting key 1102. The lower end of the upper slip 12 coincides with the lower end of the connecting key 1102. The lower slip 13 is connected inside the upper slip 12. The lower slip 13 is provided with a through threaded hole inside. The inner diameter of the threaded hole is smaller than the outer diameter of the oil pipe 02. The first sealing structure is provided below the connecting key 1102.

[0041] In this embodiment, the first gripping structure includes an upper slip 12 and a lower slip 13. The upper slip 12 is located inside the mounting hole and is connected to the outer cylinder 11 by a connecting key 1102 and a keyway. The lower slip 13 is used to grip the tubing 02. Specifically, the inner diameter of the lower slip 13 is smaller than the outer diameter of the tubing 02. Therefore, after the wellhead tubing connection device 01 is put on the tubing 02, the lower slip 13 can be put on the tubing 02 by knocking the wellhead tubing connection device 01 downward, thereby achieving the purpose of gripping the tubing 02 by the lower slip 13.

[0042] Again, along the extension direction of the mounting hole, the depth of the keyway on the upper slip 12 is greater than the depth of the connecting key 1102. Therefore, when the lower end of the upper slip 12 coincides with the lower end of the connecting key 1102, the upper slip 12 can move downward relative to the connecting key 1102, so that the upper slip 12 can transfer the thrust of the upper structure to the first sealing structure. In specific settings, for example, there are 3 connecting keys 1102.

[0043] In one embodiment, the lower slip 13 is an elastic element, and there is a relative displacement between the upper slip 12 and the lower slip 13 along the axial direction of the mounting hole. When the upper slip 12 moves upward relative to the lower slip 13, the inner diameter of the lower slip 13 decreases.

[0044] In this embodiment, when the upper slip 12 moves upward relative to the lower slip 13, the inner diameter of the lower slip 13 decreases. Therefore, after the lower slip 13 grips the tubing 02, the upper structure can be slowly lifted to move the upper slip 12 upward, further reducing the inner diameter of the lower slip 13 and making the grip between the lower slip 13 and the tubing 02 more secure. Specifically, for example, the upper structure can be slowly lifted with an initial force of 50-150kN using a workover device, so that the lower slip 13 completely grips the tubing 02. Then, the lifting force is released, allowing the wellhead tubing connection device 01 to be in a free state. It is important to note that when lifting the central tube 2, the lifting load should not exceed 70% of the strength of the tubing 02 itself to prevent the lower slip 13 from damaging the tubing 02.

[0045] In one specific embodiment, the upper structure includes an upper connector 1 and a central tube 2. The upper connector 1 has a connecting channel 101 inside. The upper connector 1 is threadedly connected to the upper end of the central tube 2. The central tube 2 has a through hole that connects the connecting channel 101 and the mating channel. The connecting channel 101 inside the upper connector 1 and the central tube 2 are isolated by an upper connector protrusion ring 102.

[0046] Specifically, the upper structure includes an upper connector 1 and a central tube 2. The upper connector 1 and the central tube 2 are connected by threads. The connection channel 101 that mates with the sealing inspection tool is set in the upper connector 1. That is, the wellhead tubing connection device 01 is connected to the sealing inspection tool through its upper connector 1, and the sealing inspection tool extends into the tubing 02 in the mating channel through the through hole in the central tube 2.

[0047] The second sealing structure includes a sealing sleeve 6 fitted onto the central tube 2. The sealing sleeve 6 is threadedly connected to the central tube 2. The central tube 2 can push the upper slip 12 downward by moving downward along the axis of the mounting hole. The sealing sleeve 6 is fixedly connected to the outer cylinder 11. Sealing elements are provided between the central tube 2 and the sealing sleeve 6, and between the sealing sleeve 6 and the outer cylinder 11.

[0048] The second sealing structure is a sealing sleeve 6, which is fixedly connected to the outer cylinder 11 and threadedly connected to the central tube 2. Therefore, by fixing the sealing sleeve 6 or the outer cylinder 11 and rotating the central tube 2, the central tube 2 can move relative to the outer cylinder 11 along the axis of the mounting hole. The downward movement of the central tube 2 pushes the lower slip 13 downward, thereby sealing the annulus between the outer cylinder 11 and the oil pipe 02 through the lower slip 13. To ensure that the downward movement of the central tube 2 can smoothly push the lower slip 13, the outer diameter of the central tube 2 needs to be greater than or equal to the inner diameter of the upper slip 12.

[0049] The sealing elements between the central tube 2 and the sealing sleeve 6, and between the sealing sleeve 6 and the outer cylinder 11, are used to achieve the sealing between the sealing sleeve 6 and the outer cylinder 11 and between the sealing sleeve 6 and the central tube 2; the sealing sleeve 6 and the outer cylinder 11 are fixedly connected by a threaded connection.

[0050] In one embodiment, a bearing 9 is fitted at the lower end of the central tube 2, the upper end of the bearing 9 is limited by the central tube protrusion ring 201, and the lower end of the bearing 9 is limited by the bearing sleeve 10. A pressure cap 7 is provided between the central tube protrusion ring 201 and the sealing sleeve 6. The pressure cap 7 is threadedly connected to the bearing sleeve 10, and the central tube 2 pushes the upper slip 12 through the bearing sleeve 10. A bushing 8 is fitted on the outside of the bearing sleeve 10. The bushing 8 extends to fit on the pressure cap 7 and blocks the bottom of the sealing sleeve 6.

[0051] In this embodiment, a bearing 9 is provided at the lower end of the central tube 2. The bearing 9 is limited by the central tube protrusion ring 201 and the bearing sleeve 10, and the bearing sleeve 10 is fixed by the pressure cap 7. The arrangement of the bearing sleeve 10 and the bearing 9 changes the downward rotation of the central tube 2 into the downward movement of the bearing sleeve 10, thereby pushing the upper clamp 12 downward through the downward movement of the bearing sleeve 10.

[0052] In one embodiment, the upper end of the outer cylinder 11 is provided with an anti-rotation structure. The anti-rotation structure cooperates with the outer cylinder 11 to fix the outer cylinder 11 by fixing the anti-rotation structure. The anti-rotation structure is fixedly connected to the sealing sleeve 6.

[0053] In one embodiment, the anti-rotation structure includes an anti-rotation ring 5 and a back cap 4. The lower end of the anti-rotation ring 5 is provided with a plurality of insert teeth 51, and a slot is formed between two adjacent insert teeth 51. The upper end of the outer cylinder 11 is provided with a groove that mates with the insert teeth 51, and the upper end of the outer cylinder 11 is provided with a protrusion 1101 that mates with the slot. The anti-rotation ring 5 and the outer cylinder 11 are connected by the insert teeth 51 mates with the groove, and the slot mates with the protrusion 1101. The anti-rotation ring 5 is sleeved on the sealing sleeve 6. The back cap 4 is located on the side of the anti-rotation ring 5 away from the outer cylinder 11, and the back cap 4 is threadedly connected to the sealing sleeve 6.

[0054] In this embodiment, the anti-rotation ring 5 and the outer cylinder 11 are connected by inserting teeth 51 into grooves, slots into protrusions 1101, and the upper limit of the anti-rotation ring 5 is achieved by the back cap 4. Specifically, the back cap 4 is threadedly connected to the sealing sleeve 6 to fix the anti-rotation ring 5 between the back cap 4 and the outer cylinder 11.

[0055] After the anti-rotation ring 5 is fixed, the outer cylinder 11 can be fixed because the anti-rotation ring 5 and the outer cylinder 11 are connected by insertion. After the outer cylinder 11 is fixed, the central tube 2 or the upper connector 1 can be rotated to move the central tube 2 along the axis of the mounting hole.

[0056] In one embodiment, the sealing sleeve 6 includes a first sealing sleeve section and a second sealing sleeve section. The outer diameter of the first sealing sleeve section is smaller than the outer diameter of the second sealing sleeve section. The second sealing sleeve section is threadedly connected to the outer cylinder 11. The anti-rotation ring 5 is fitted on the first sealing sleeve section. The back cap 4 is threadedly connected to the first sealing sleeve section. A first screw 3 is connected between the central tube 2 and the sealing sleeve 6.

[0057] In this embodiment, the first screw 3 is provided to prevent the central tube 2 from moving downwards prematurely, for example, if the oil pipe 02 is not inserted into the mating channel, or if the central tube 2 moves downwards before the oil pipe 02 is gripped by the lower slip 13. Premature downward movement of the central tube 2 may result in the oil pipe 02 being unable to be gripped by the lower slip 13, the oil pipe 02 being unable to be inserted into the mating channel, or the first sealing structure failing to seal.

[0058] In practical use, after the slip 13 grabs the oil pipe 02, the first screw 3 is removed, and the central tube 2 is moved down so that the annulus between the outer cylinder 11 and the oil pipe 02 can be sealed through the first sealing structure.

[0059] In one embodiment, the first sealing structure includes a sealing cylinder 15 with an internal mating channel. The upper end of the sealing cylinder 15 contacts the lower end of the first gripping structure, and the lower end of the sealing cylinder 15 contacts the first limiting structure. The sealing cylinder 15 can be deformed into the annulus between the sealing outer cylinder 11 and the oil pipe 02 under the action of the first gripping structure.

[0060] In this embodiment, the first sealing structure is a sealing cylinder 15. The upper end of the sealing cylinder 15 contacts the connecting key 1102 on the inner wall of the outer cylinder 11, and the lower end of the sealing cylinder 15 is limited by the first limiting structure. Therefore, when the central tube 2 moves downward, the lower slip 13 begins to move downward. The lower slip 13 moves downward and squeezes the sealing cylinder 15. After being squeezed, the inner diameter of the sealing cylinder 15 gradually shrinks. The oil pipe 02 is located inside the sealing cylinder 15. Therefore, the sealing cylinder 15 eventually deforms to the annulus between the sealing oil pipe 02 and the outer cylinder 11. In addition, it is necessary to satisfy the condition that when the lower slip 13 moves downward to the point where it can no longer move downward, the sealing cylinder 15 has already deformed to the annulus between the sealing oil pipe 02 and the outer cylinder 11. That is, when the lower slip 13 moves downward to the bottom of the keyway and contacts the upper end of the connecting key 1102, the sealing cylinder 15 has already deformed to the annulus between the sealing oil pipe 02 and the outer cylinder 11.

[0061] In one embodiment, a pressure pad 14 is provided above the sealing cylinder 15, and a support pad 16 is provided below the sealing cylinder 15. In this embodiment, the lower end of the lower slip 13 contacts the pressure pad 14, and the lower slip 13 moves down to push the pressure pad 14 to compress the sealing cylinder 15. The lower end of the sealing cylinder 15 contacts the first limiting structure through the support pad 16.

[0062] In one embodiment, the first limiting structure includes a connecting sleeve 17 that is threadedly connected to the outer cylinder 11, and a mating channel is disposed inside the connecting sleeve 17, with the upper end of the connecting sleeve 17 in contact with the first sealing structure.

[0063] In one embodiment, the first limiting structure is connected to a second gripping structure, which is also used to connect to the oil pipe 02.

[0064] Specifically, the second gripping structure includes a guide shoe 20, which is located inside the connecting sleeve 17 and is threadedly connected to the connecting sleeve 17. A second screw 19 is connected between the connecting sleeve 17 and the guide shoe 20. Along the axial direction of the mounting hole, the width of the screw hole on the guide shoe 20 that mates with the second screw 19 is greater than the diameter of the second screw 19. A slip ring 18 composed of several slip fan rings is provided between the connecting sleeve 17 and the guide shoe 20. There is a gap between two adjacent slip fan rings. Each slip fan ring mates with the inclined surface on the guide shoe 20. The maximum inner diameter of the slip ring 18 composed of several slip fan rings is smaller than the outer diameter of the oil pipe 02.

[0065] In this embodiment, the connecting sleeve 17 is internally threaded to the guide shoe 20, and the slip ring 18 is disposed between the guide shoe 20 and the connecting sleeve 17. The upper part of the slip ring 18 is limited by the connecting sleeve 17, and the lower end of the slip ring 18 is engaged with the inclined surface on the guide shoe 20. The slip ring 18 includes several slip fan rings, and there is a gap between two adjacent slip fan rings. The existence of this gap allows the diameter of the slip ring 18 composed of several slip fan rings to be changed.

[0066] A second screw 19 is also connected between the connecting sleeve 17 and the guide shoe 20, and the width of the screw hole corresponding to the second screw 19 on the guide shoe 20 is greater than the diameter of the second screw 19. Therefore, the guide shoe 20 can move relative to the connecting sleeve 17 along the axial direction of the mounting hole. The guide shoe 20 and each slip ring are engaged by a bevel, so the diameter of the slip ring 18 can be changed when the guide shoe 20 moves.

[0067] Furthermore, the maximum inner diameter of the slip ring 18, composed of several slip fan rings, is smaller than the outer diameter of the tubing 02. Therefore, the slip ring 18 can be connected to the tubing 02 through an interference fit with the tubing 02 inside. In specific operation, the guide shoe 20 is rotated to maximize the diameter of the slip ring 18. Then, the wellhead tubing connection device 01 is placed on the tubing 02, and the upper connector 1 is knocked downward to move the wellhead tubing connection device 01 downward, allowing the tubing 02 to pass through the slip ring 18 and the lower slip 13. After the tubing 02 passes through the lower slip 13, the guide shoe 20 is rotated to move the guide shoe 20 upward relative to the connecting sleeve 17. As the guide shoe 20 moves upward, the inner diameter of the slip ring 18 decreases, thereby making the connection between the slip ring 18 and the tubing 02 more secure.

[0068] Finally, threads can also be provided on the inner wall of each slip ring 18, and the slip ring 18 is interference-fitted with the oil pipe 02 through the threads on the inner wall.

[0069] To facilitate understanding of the wellhead tubing connection device 01 in this embodiment of the invention, the process of connecting the wellhead tubing string and tubing 02 and the release process after connection are described below:

[0070] The process of connecting the wellhead tubing string to the tubing 02 is as follows: Adjust the guide shoe 20 to the maximum inner diameter of the slip ring 18, put the guide shoe 20 on the tubing 02, and tap the upper connector 1 downwards to insert the tubing 02 into the slip ring 18 and the lower slip 13; then, rotate the guide shoe 20 to reduce the inner diameter of the slip ring 18 again, so that the slip ring 18 grips the tubing 02 more firmly; next, use the workover equipment to slowly lift the upper connector 1 with an initial force of 50-150kN, so that the lower slip 13 completely grips the tubing 02; finally, keep the outer cylinder 11 fixed and rotate the upper connector 1, so that the upper connector 1 pushes the lower slip 13 downwards, so that the sealing cylinder 15 deforms to seal the annulus between the wellhead tubing connection device 01 and the outer cylinder 11.

[0071] The reconnection and release process is as follows: The outer cylinder 11 is fixed, and the upper connector 1 is rotated in the opposite direction, causing the upper connector 1 to move upwards and the sealing cylinder 15 to reset. Next, the upper connector 1 is struck downwards, causing the upper slip 12 to move downwards relative to the lower slip 13, increasing the inner diameter of the lower slip 13. The guide shoe 20 is adjusted to the maximum inner diameter of the slip ring 18. The outer cylinder 11 is rotated again, causing the upper slip 12 to rotate and further increasing the inner diameter of the lower slip 13. Finally, the upper connector 1 is lifted, separating the tubing 02 from the lower slip 13 and slip ring 18. If the wellhead tubing connection device 01 cannot properly disengage from the tubing 02, the outer cylinder 11 can be rotated further to forcibly disengage the lower slip 13 from the tubing string.

[0072] The assembly process of the wellhead tubing connection device 01 according to an embodiment of the present invention is described below:

[0073] Remove the outer cylinder 11 and place it horizontally on the pliers to secure it (Note: Avoid using excessive force to secure the outer cylinder 11 here) to ensure the stability of the outer cylinder 11;

[0074] Insert the lower slip 13 into the upper slip 12 by rotating it counterclockwise (when the lower slip 13 is rotated into the upper slip 12, the left end face of the lower slip 13 is about 10cm away from the left end face of the upper slip 12, and the left end face of the lower slip 13 is inside the upper slip 12, so that the upper slip 12 and the lower slip 13 are in an unlocked state).

[0075] Place the upper slip 12 and the lower slip 13 into the outer cylinder 11 as a whole (Note: Here, the lower section of the keyway at the lower end of the upper slip 12 is aligned with the lower section of the connecting key 1102 on the outer cylinder 11).

[0076] Assemble the central tube 2, sealing sleeve 6, pressure cap 7, bushing 8, bearing 9, and bearing sleeve 10 into a single unit. The assembly sequence is as follows: Insert the pressure cap 7 and sealing sleeve 6 into the central tube 2 from the left end; then clamp the central tube 2 horizontally onto another pair of pliers and secure it; rotate the sealing sleeve 6 clockwise and insert it onto the central tube 2. After installation, the pressure cap 7 should contact the central tube's convex ring 201, and the sealing sleeve 6 should contact the pressure cap 7; insert the bearing 9 from the right end of the central tube 2, making it contact the central tube's convex ring 201; next, rotate the bearing sleeve 10 clockwise until it is installed on the pressure cap 7; then, insert the bushing 8 onto the bearing sleeve 10, with the left end of the bushing 8 contacting the sealing sleeve 6; thus, assemble the central tube 2, sealing sleeve 6, pressure cap 7, bushing 8, bearing 9, and bearing sleeve 10 into a single unit.

[0077] Place the assembled parts into the outer cylinder 11, and rotate the center tube 2 clockwise to make the bushing 8 contact the upper clamp 12;

[0078] Install the anti-rotation ring 5 on the outer cylinder 11, then rotate the back cap 4 clockwise to install it onto the sealing sleeve 6; connect the sealing sleeve and the central tube 2 with the first screw 3, then rotate the upper connector 1 clockwise to install it onto the left end of the central tube 2;

[0079] Insert the pressure pad 14, sealing cylinder 15 and support pad 16 into the right end face of the outer cylinder 11 in sequence; connect the connecting sleeve 17 to the lower end of the outer cylinder 11; insert the slip ring 18 into the right end of the connecting sleeve 17, then rotate the guide shoe 20 clockwise to install it onto the connecting sleeve 17, and finally insert the second screw 19.

[0080] Furthermore, the disassembly process of the wellhead tubing connection device 01 in this embodiment of the invention is described below:

[0081] Clamp the wellhead tubing connection device 01 horizontally onto the pliers (the pliers are clamped in the middle of the outer cylinder 11; avoid applying excessive force to the outer cylinder 11 here) to ensure the stability of the wellhead tubing connection device 01.

[0082] Use a pipe wrench to clamp the upper connector 1, then rotate it counterclockwise to loosen the threads and remove it;

[0083] Remove the back cap 4 by rotating counterclockwise. Next, remove the anti-rotation ring 5. Then, use pipe wrenches to clamp the middle of the sealing sleeve 6 (be careful not to damage the threads of the sealing sleeve 6). Then, rotate the sealing sleeve 6 counterclockwise to loosen the threads and remove the sealing sleeve 6, the center tube 2, and the bearing sleeve 10 as a whole. Next, clamp the removed whole parts on another pair of pliers and disassemble them one by one.

[0084] Wearing protective gloves, reach into the outer cylinder 11 and remove the upper slip 12 and lower slip 13 as a whole;

[0085] Use a screwdriver to remove the second screw 19, then use a pipe wrench to clamp the guide shoe 20, rotate it counterclockwise to loosen it, and then remove it; remove the slip ring 18, and then use a pipe wrench to clamp the connecting sleeve 17; rotate it counterclockwise to loosen it until it is completely removed.

[0086] Wearing gloves, reach your hands into the outer cylinder 11 and remove the support pad 16, sealing cylinder 15 and pressure pad 14 in sequence.

[0087] After removing the outer cylinder 11 from the pliers, the disassembly work is complete.

[0088] The wellhead tubing connection device 01 of this invention is used to cut the tubing when it is difficult to disassemble after the tubing string gets stuck. The wellhead tubing connection device 01 is then used to connect the cut tubing to the tubing. After connection, the tubing can be sealed. The upper part of the tool can be connected to the circulation tool and pipeline to meet the requirements of circulation washing and well pressure, and ensure the safe and controllable implementation of subsequent construction.

[0089] The wellhead tubing connection device of this invention is inserted into the cut tubing, and the device and tubing can be sealed. Therefore, through a pre-connected well-washing and pressure process, a circulation channel from the tubing to the annulus can be established, while simultaneously meeting the conditions for unsticking activities at normal tonnage levels. This forms a complete set of rapid risk management processes for stuck tubing. The device of this invention is small in size and easy to operate. It not only meets the conditions for unsticking activities at normal tonnage levels but also solves the problem of emergency well control at the wellhead, eliminates safety hazards, improves well workover safety, and ensures the safe and controllable implementation of subsequent operations.

[0090] In addition, embodiments of the present invention also provide a sealing inspection tool, such as... Figure 2 As shown, the sealing inspection tool in this embodiment is used to seal the annulus in the tubing 02 connected to the wellhead tubing connection device 01, and also to inspect the seal between the wellhead tubing connection device 01 and the tubing 02, as well as whether there is any leakage in the seal inside the tubing 02.

[0091] Specifically, such as Figure 3 As shown, the sealing inspection tool includes a central rod 031, and a connector 032 is sleeved on the upper part of the central rod 031. The connector 032 can move along the length direction of the central rod 031 and can be fixed on the central rod 031. The connector 032 is provided with a mating structure 0322 that is sealed to the connection channel 101 of the wellhead tubing connection device 01. Therefore, the connection channel 101 of the wellhead tubing connection device 01 can be sealed to the mating structure 0322 of the sealing inspection tool.

[0092] The lower part of the center rod 031 is fitted with a third sealing structure. After being subjected to the force of the connecting piece 032, the outer diameter of the third sealing structure can be increased to seal and connect with the oil pipe 02 outside it. The lower end of the center rod 031 is fixedly connected with a second limiting structure, which is used to limit the third sealing structure.

[0093] The sealing inspection tool extends into the oil pipe 02 that enters the mating channel. The third sealing structure of the sealing inspection tool can seal the annulus in the oil pipe 02. The second limiting structure is fixedly connected to the center rod 031. The second limiting structure is used to limit the third sealing structure.

[0094] The connector 032 is provided with a pressure port 0321 and a pressure outlet 0323. The pressure port 0321 and the pressure outlet 0323 are connected. The pressure port 0321 is located above the mating structure 0322, and the pressure outlet 0323 is located below the mating structure 0322. Figure 2 As shown, the upper part of the sealing inspection tool 03 and the upper part of the wellhead tubing connection device 01 are sealed together. The third sealing structure at the lower part of the sealing inspection tool 03 can seal the annulus inside the tubing 02. The first sealing device at the lower part of the wellhead tubing connection device 01 can seal the annulus between it and the tubing 02. Therefore, a closed space can be formed between the sealing inspection tool 03, the wellhead tubing connection device 01, and the tubing 02. The sealing inspection tool 03 can also be used to inspect the sealing performance of this closed space. Specifically, the pressure port 0321 is located above the mating structure 0322, and the pressure outlet 0323 is located below the mating structure 0322. Pressurization is performed through the pressure port 0321, and pressurized medium flows from the pressure outlet 0323 into the aforementioned closed space. Figure 2 The direction of the arrow indicates the flow direction of the pressurized medium. If the pressure does not decrease after stabilization, it indicates that the sealing performance of the enclosed space is good.

[0095] In one specific embodiment, the mating structure 0322 is an external thread structure, and the connecting channel 101 is a threaded hole that mates with the external thread structure; the connecting member 032 is threadedly connected to the center rod 031, and two sets of seals are provided between the connecting member 032 and the center rod 031, one set of seals being located above the pressure port 0321, and the other set of seals being located below the pressure outlet 0323.

[0096] In this embodiment, the mating structure 0322 and the connecting channel 101 are connected by a thread. The connecting member 032 and the center rod 031 are also connected by a thread. Therefore, the connecting member 032 can move along the length of the center rod 031, and when it moves to a certain point, the connecting member 032 can be fixed to the center rod 031 by the thread.

[0097] The addition of two sets of seals prevents pressurized media from leaking out from the gap between connector 032 and center rod 031.

[0098] In one embodiment, the third sealing structure is a sealing rubber sleeve 033, which is sleeved on the connector 032. The connector 032 is provided with a retaining ring, which is located above the sealing rubber sleeve 033. The outer diameter of the retaining ring is larger than the inner diameter of the sealing rubber sleeve 033.

[0099] In this embodiment, the third sealing structure is a sealing rubber sleeve 033. The upper part of the sealing rubber sleeve 033 is limited by a retaining ring, and the lower part of the sealing rubber sleeve 033 is limited by a second limiting structure. The retaining ring and the connecting piece 032 are an integral structure, and the outer diameter of the retaining ring is larger than the inner diameter of the sealing rubber sleeve 033.

[0100] In one embodiment, the second limiting structure includes a limiting block 034, which is threadedly connected to the center rod 031. A mating block 035 is provided between the limiting block 034 and the sealing tube 033. The lower end of the mating block 035 contacts the limiting block 034, and the upper end of the mating block 035 contacts the sealing tube 033. The mating block 035 presses against the sealing tube 033.

[0101] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0102] Furthermore, the terms "a," "two," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly defined.

[0103] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A sealing inspection tool, characterized in that, The sealing inspection tool includes a central rod, with a connector sleeved on the upper part of the central rod. The connector is movable along the length of the central rod and can be fixed to the central rod. The connector has a mating structure that seals with the connection channel of the wellhead tubing connection device. The connector has a pressure port and a pressure outlet, with the pressure port communicating with the pressure outlet. The pressure port is located above the mating structure, and the pressure outlet is located below the mating structure. A third sealing structure is sleeved on the lower part of the central rod. When the third sealing structure is subjected to the force of the connector, its outer diameter can increase to seal with the tubing outside it. A second limiting structure is fixedly connected to the lower end of the central rod, which limits the third sealing structure. The mating structure is an external thread structure, and the connection channel is a threaded hole that mates with the external thread structure. The connector is threadedly connected to the central rod, and two sets of sealing elements are provided between the connector and the central rod. One set of sealing elements is located above the pressure port, and the other set is located below the pressure outlet. The wellhead tubing connection device includes an outer cylinder, and an installation hole extending along the length of the outer cylinder and penetrating the outer cylinder is provided inside the outer cylinder; The mounting hole is provided with, from top to bottom, an upper structure, a first gripping structure, a first sealing structure, and a first limiting structure. Both the first sealing structure and the first limiting structure have mating channels extending from the upper end to the lower end, which are used for inserting an oil pipe. The upper structure has a connecting channel for sealing and fixing with a sealing inspection tool inside the oil pipe, and the connecting channel communicates with the mating channel. The first gripping structure can be connected to the oil pipe and can move downward under the action of the upper structure; the first sealing structure can seal the annulus between the outer cylinder and the oil pipe under the action of the first gripping structure; the first limiting structure is fixedly connected to the outer cylinder; A second sealing structure is provided between the upper structure and the outer cylinder. The second sealing structure is fixedly and sealed to the outer cylinder and to the upper structure. The upper structure is movable relative to the second sealing structure, and the second sealing structure is fixed to the upper structure.

2. The sealing inspection tool according to claim 1, characterized in that, The first gripping structure includes an upper slip and a lower slip. The lower part of the upper slip has several keyways extending through the lower end of the upper slip. Several connecting keys are fixedly connected inside the outer cylinder. The connecting keys mate with the corresponding keyways and are aligned along the extension direction of the mounting hole. The depth of the keyway is greater than the length of the connecting key. The lower end of the upper slip coincides with the lower end of the connecting key. The lower slip is connected inside the upper slip and has a through threaded hole inside. The inner diameter of the threaded hole is smaller than the outer diameter of the oil pipe. The first sealing structure is located below the connecting key.

3. The sealing inspection tool according to claim 2, characterized in that, The lower clamp is an elastic element, and there is a relative displacement between the upper clamp and the lower clamp along the axial direction of the mounting hole. When the upper clamp moves upward relative to the lower clamp, the inner diameter of the lower clamp decreases.

4. The sealing inspection tool according to claim 2, characterized in that, The upper structure includes an upper connector and a central tube. The upper connector has a connecting channel inside. The upper connector is threaded to the upper end of the central tube. The central tube has a through hole that connects the connecting channel and the mating channel. The second sealing structure includes a sealing sleeve fitted on the central tube, the sealing sleeve being threaded to the central tube, the central tube moving downward along the axial direction of the mounting hole to push the upper slip downward, the sealing sleeve being fixedly connected to the outer cylinder, and sealing elements being provided between the central tube and the sealing sleeve, and between the sealing sleeve and the outer cylinder.

5. The sealing inspection tool according to claim 4, characterized in that, A bearing is fitted at the lower end of the central tube. The upper end of the bearing is limited by a central tube convex ring, and the lower end of the bearing is limited by a bearing sleeve. A pressure cap is provided between the central tube convex ring and the sealing sleeve. The pressure cap is threadedly connected to the bearing sleeve. The central tube pushes the upper slip through the bearing sleeve. A bushing is fitted on the outside of the bearing sleeve. The bushing extends to fit on the pressure cap and blocks the bottom of the sealing sleeve.

6. The sealing inspection tool according to claim 4, characterized in that, The upper end of the outer cylinder is provided with an anti-rotation structure. The anti-rotation structure cooperates with the outer cylinder to fix the outer cylinder by fixing the anti-rotation structure. The anti-rotation structure is fixedly connected to the sealing sleeve.

7. The sealing inspection tool according to claim 6, characterized in that, The anti-rotation structure includes an anti-rotation ring and a back cap. The lower end of the anti-rotation ring is provided with several teeth, and a slot is formed between two adjacent teeth. The upper end of the outer cylinder is provided with a groove that mates with the teeth, and the upper end of the outer cylinder is provided with a protrusion that mates with the slot. The anti-rotation ring and the outer cylinder are connected by the teeth engaging with the groove and the slot engaging with the protrusion. The anti-rotation ring is fitted onto the sealing sleeve. The back cap is located on the side of the anti-rotation ring away from the outer cylinder, and the back cap is threadedly connected to the sealing sleeve.

8. The sealing inspection tool according to claim 7, characterized in that, The sealing sleeve includes a first sealing sleeve section and a second sealing sleeve section. The outer diameter of the first sealing sleeve section is smaller than the outer diameter of the second sealing sleeve section. The second sealing sleeve section is threadedly connected to the outer cylinder. The anti-rotation ring is fitted on the first sealing sleeve section. The back cap is threadedly connected to the first sealing sleeve section. A first screw connects the central tube to the sealing sleeve.

9. The sealing inspection tool according to claim 1, characterized in that, The first sealing structure includes a sealing cylinder with the mating channel inside. The upper end of the sealing cylinder contacts the lower end of the first gripping structure, and the lower end of the sealing cylinder contacts the first limiting structure. The sealing cylinder can be deformed under the action of the first gripping structure to seal the annulus between the outer cylinder and the oil pipe.

10. The sealing inspection tool according to claim 9, characterized in that, A pressure pad is provided above the sealing cylinder, and a support pad is provided below the sealing cylinder.

11. The sealing inspection tool according to claim 1, characterized in that, The first limiting structure includes a connecting sleeve that is threadedly connected to the outer cylinder, the connecting sleeve having a mating channel inside, and the upper end of the connecting sleeve contacting the first sealing structure; the first limiting structure is connected to a second gripping structure, the second gripping structure being used to connect to the oil pipe.

12. The sealing inspection tool according to claim 11, characterized in that, The second gripping structure includes a guide shoe located inside the connecting sleeve and threadedly connected to the connecting sleeve; a second screw is connected between the connecting sleeve and the guide shoe, and the width of the screw hole on the guide shoe that mates with the second screw along the axial direction of the mounting hole is greater than the diameter of the second screw; a slip ring composed of several slip fan rings is provided between the connecting sleeve and the guide shoe, with a gap between two adjacent slip fan rings, and each slip fan ring mates with an inclined surface on the guide shoe, and the maximum inner diameter of the slip ring composed of several slip fan rings is smaller than the outer diameter of the oil pipe.

13. The sealing inspection tool according to claim 1, characterized in that, The third sealing structure is a sealing rubber tube, which is sleeved on the connector. The connector is provided with a retaining ring, which is located above the sealing rubber tube. The outer diameter of the retaining ring is larger than the inner diameter of the sealing rubber tube.

14. The sealing inspection tool according to claim 13, characterized in that, The second limiting structure includes a limiting block, which is threadedly connected to the center rod. A mating block is provided between the limiting block and the sealing rubber tube. The lower end of the mating block contacts the limiting block, and the upper end of the mating block contacts the sealing rubber tube. The mating block presses on the sealing rubber tube.

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