Subsea anchor and tieback system

Abstract

The application belongs to the technical field of oil well fracturing reconstruction, and discloses a low-temperature-resistant self-sealing anchoring and back-connection device, which comprises a main joint, an inner sealing joint, a slip, a hanging joint and an insertion pipe, the top end of the inner sealing joint is inserted into the inside of the bottom end of the main joint and is in sliding sealing connection with the main joint; the slip is arranged outside the inner sealing joint and is fixedly connected with the bottom end of the main joint; the top end of the hanging joint is connected with the inner sealing joint, the bottom end of the slip is in abutment with the top end of the hanging joint, and the bottom end of the hanging joint can be seated on the top end of a hanger; the insertion pipe is connected with the bottom end of the hanging joint, and the insertion pipe can be inserted into the inside of the hanger. The axial movement of the insertion pipe can be effectively limited, and the sealing effect is ensured; the slip is opened and anchored under the action of the main joint and the hanging joint, and the central position and stability of the inner sealing joint are ensured; the inner sealing joint and the insertion pipe are in a fixed state under the action of pressure in the axial direction, do not creep up and down, the sealing property is not affected by temperature, and the low-temperature resistance effect is good.

Description

Technical Field

[0001] This invention relates to the field of oil well fracturing technology, and in particular to a low-temperature resistant self-sealing anchoring reconnection device. Background Technology

[0002] In the field of oil and gas field development technology, with the continuous extension of production time, old blocks in various oilfields generally face problems such as low production and water breakthrough. In recent years, in order to tap the potential of remaining oil reservoirs, improve oilfield recovery rate, reduce drilling operation costs, and lower overall development costs, for low-permeability blocks and low-production horizontal wells, volumetric fracturing has been developed, forming a large-volume dual-seal single-card staged fracturing process that integrates "comprehensive energy replenishment, dynamic temporary plugging, and synchronous fracturing." However, this process suffers from problems such as long construction cycle and high construction costs. In order to improve fracturing efficiency, shorten the construction cycle, reduce construction costs, and meet the requirements of repeated and efficient staged fracturing technology for horizontal wells, research has been conducted on bridge-fracturing combined with fracturing tools and processes after large-diameter full-bore wellbore reconstruction.

[0003] Currently, the casing reworking of low-permeability tight oil and gas horizontal wells in Changqing Oilfield has entered the experimental stage. The main approach involves running a φ14.3mm uncoupled casing into a φ139.7mm casing for secondary well completion (casing within a casing), followed by reconnection and then repeated fracturing and re-fracturing of the old well. For example... Figure 1 As shown, the wellbore re-creation depth structure includes a back-connecting casing 1', an insert head 2', a back-connectable hanger 3', an outer casing 4', an inner casing 5', a pressure ball seat 6', a first float collar 7', a second float collar 8', and a guide shoe 9'. Among them, the back-connecting casing 1' is a 4-1 / 2" tube, the outer casing 4' and the inner casing 5' are 5-1 / 2" tubes and 4-1 / 2" tubes, respectively. Due to the influence of the casing size, the insert head 2' used at the end of the back-connecting casing 1' cannot be connected to the hydraulic anchor commonly used in fracturing, thus failing to achieve effective fixation of the back-connecting casing 1'. In particular, when CO2 pre-fracturing fluid is added, under the action of the upward force, the sealing performance of the insert head 2' during the fracturing process is poor, and the sealing reliability is low.

[0004] In the trial construction of re-fractured old wells, the sealing difference caused by the upward force generated by pressure is a problem. Currently, the main method used is to compensate by lowering the return tubing string to compensate for this, but the effectiveness is uncertain. It is also uncertain whether the insertion head 2' will still experience tubing string creep due to pressure fluctuations caused by fracturing. The main challenges currently facing re-fractured tubing strings in wellbore reconstruction are:

[0005] (1) Due to size limitations, it is impossible to connect conventional anchors. The reconnection device has no anchor and relies solely on the self-weight of the reconnection sleeve 1' to offset the upward force generated by the high pressure during fracturing construction, resulting in low reliability.

[0006] (2) The back-insertion seal relies solely on the sealing ring at the 2' insertion head. The low temperature during CO2 pre-fracturing results in poor sealing reliability.

[0007] (3) When the weight of the reconnecting sleeve is insufficient, the tubing will move upward under high pressure, affecting the sealing performance.

[0008] Currently, there is a large demand for repeated fracturing technology for old wells, and the key technology for well re-connection is the core factor affecting whether subsequent staged fracturing can proceed smoothly. Therefore, based on the existing test results, researching low-temperature self-sealing anchoring re-connection devices is of great significance for solving the problem of re-insertion sealing in repeated fracturing of old wells. Summary of the Invention

[0009] The purpose of this invention is to provide a low-temperature resistant self-sealing anchoring reconnection device to solve the problem of low sealing reliability caused by low temperature, inability of the reconnection device to anchor, and pipe movement during the fracturing construction of old wells.

[0010] To achieve this objective, the present invention adopts the following technical solution:

[0011] The low-temperature resistant self-sealing anchoring reconnection device includes:

[0012] Main connector;

[0013] An inner sealing joint, wherein the top end of the inner sealing joint is inserted into the bottom end of the main joint and is slidably and sealingly connected to the main joint;

[0014] The slip is located on the outside of the inner sealing joint and is fixedly connected to the bottom end of the main joint;

[0015] The hook connector has its top end connected to the inner sealing connector, the bottom end of the collet abuts against the top end of the hook connector, and the bottom end of the hook connector can sit on the top end of the hanger.

[0016] An insertion tube is connected to the bottom end of the hanger and can be inserted into the hanger.

[0017] Optionally, the inner wall of the inner sealing joint protrudes from the inner wall of the main joint to form a pressure-bearing surface.

[0018] Optionally, the pressure-bearing surface is inclined downward along the direction from the outer wall of the inner sealing joint toward the inner wall.

[0019] Optionally, a sliding surface is formed between the top end face of the hook connector and the bottom end face of the chuck, and the sliding surface slopes downward from the inner wall to the outer wall of the hook connector.

[0020] Optionally, the outer diameter of the hook connector is larger than the outer diameter of the hanger, and the bottom end face of the hook connector can abut against the top end face of the hanger.

[0021] Optionally, a plurality of first sealing elements are provided axially spaced on the outer wall of the top end of the inner sealing joint, and the first sealing elements can press and seal between the outer wall of the inner sealing joint and the inner wall of the main joint.

[0022] Optionally, the first seal is a fluororubber ring.

[0023] Optionally, a plurality of second seals are provided at axial intervals on the outer wall of the insertion tube, and the second seals are vulcanized on the outer wall of the insertion tube.

[0024] Optionally, the low-temperature resistant self-sealing anchoring reconnection device further includes a connecting pipe, with the two ends of the connecting pipe respectively connected to the main connector and the slip, and the inner sealing connector slidably connected inside the connecting pipe.

[0025] Optionally, the bottom end of the main connector and the top end of the inner sealing connector are both located inside the connecting pipe, and the initial distance between the top end of the inner sealing connector and the bottom end of the main connector is not less than the distance difference before and after the slip is opened.

[0026] The beneficial effects of this invention are:

[0027] The low-temperature resistant self-sealing anchoring reconnection device of this invention connects the inner sealing joint and the insertion tube via a hook joint. When the hook joint is positioned at the top of the hanger, the insertion tube can be inserted into the hanger for positioning and installation. The hook joint effectively restricts the axial movement of the insertion tube, ensuring a sealing effect. By providing a locking slip at the bottom of the main joint, which abuts against the top of the hook joint, the locking slip opens under downward pressure from both the main joint and the hook joint, further fixing the hook joint to the top of the hanger. This also ensures the centered position and stability of the inner sealing joint, further improving sealing performance. The inner sealing joint and the insertion tube remain fixed under axial pressure, without vertical creep, and the sealing performance is unaffected by temperature, exhibiting excellent low-temperature resistance. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the well depth structure in existing wellbore reconstruction technology;

[0029] Figure 2 This is a schematic diagram of the lowering state of the low-temperature self-sealing anchoring reconnection device provided in the embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the working state of the low-temperature self-sealing anchoring reconnection device provided in the embodiment of the present invention;

[0031] Figure 4 yes Figure 3 A magnified structural diagram of region A in the middle.

[0032] In the picture:

[0033] 1' Reconnecting sleeve; 2' Insert head; 3' Reconnectable hanger; 4' Outer sleeve; 5' Inner sleeve; 6' Pressing ball seat; 7' First float hoop; 8' Second float hoop; 9' Guide shoe;

[0034] 1. Main connector; 2. Inner sealing connector; 21. First sealing element; 22. Pressure bearing surface; 3. Slipper; 31. Second bevel; 4. Hanger connector; 41. First bevel; 5. Insertion tube; 51. Second sealing element; 6. Connecting tube. Detailed Implementation

[0035] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0036] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" 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 based on the specific circumstances.

[0037] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0038] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0039] This invention provides a low-temperature resistant self-sealing anchoring reconnection device, such as... Figures 2-4 As shown, the device includes a main connector 1, an inner sealing connector 2, a slip 3, a hanger connector 4, and an insertion tube 5. The main connector 1, slip 3, hanger connector 4, and insertion tube 5 are arranged sequentially from top to bottom. The inner sealing connector 2 is slidably connected inside the main connector 1, and the top end of the inner sealing connector 2 is inserted into the bottom end of the main connector 1 and slidably sealed to the main connector 1. The slip 3 is located outside the inner sealing connector 2 and is fixedly connected to the bottom end of the main connector 1. The top end of the hanger connector 4 is connected to the inner sealing connector 2, and the bottom end of the slip 3 abuts against the top end of the hanger connector 4. The bottom end of the hanger connector 4 can sit on the top end of the hanger. The insertion tube 5 is connected to the bottom end of the hanger connector 4 and can be inserted into the interior of the hanger 3.

[0040] Combination Figure 1 The low-temperature self-sealing anchoring reconnection device provided in this embodiment is equivalent to the insertion head 2' in the wellbore reconstruction structure, which is used to solve the problem of poor sealing when the insertion head 2' is inserted into the reconnectable hanger 3'. It can be understood that in this embodiment, the low-temperature self-sealing anchoring reconnection device is set between the reconnection sleeve and the hanger.

[0041] The low-temperature self-sealing anchoring reconnection device of the present invention connects the inner sealing joint 2 and the insertion tube 5 through a hook joint 4. Both ends of the hook joint 4 are internally threaded, and the ends of the inner sealing joint 2 and the insertion tube 5 have external threads that engage with the internal threads at both ends of the hook joint 4. When the hook joint 4 is positioned at the top of the hanger, the insertion tube 5 can be inserted into the hanger for positioning. During fracturing, the hook joint 4 can abut against the top of the hanger under upward pressure to prevent the insertion tube 5 from moving upward, while effectively limiting the axial downward movement of the insertion tube 5, thus ensuring that the insertion tube 5 does not have axial creeping movement, which is beneficial to ensuring the sealing effect of the insertion tube 5. In this embodiment, in the lowered state, as... Figure 2 The outer wall of the slip 3 is flush with the outer wall of the connector 4, meaning they have the same outer diameter. In operation, as... Figure 3 The slip 3 opens to achieve anchoring. It can be understood that by setting the slip 3 at the bottom of the main connector 1, the slip 3 is serrated, and its bottom end abuts against the top of the hook connector 4. When the main connector 1 is subjected to continuous downward pressure, the slip 3 opens under the action of the main connector 1 and the hook connector 4, further anchoring the hook connector 4 to the top of the hanger. This also ensures the centered position and stability of the inner sealing connector 2, further improving sealing performance. The inner sealing connector 2 and the insertion tube 5 are fixed in a fixed state under axial pressure, without vertical creep, and the sealing performance is unaffected by temperature, exhibiting good low-temperature resistance.

[0042] Optionally, the inner wall of the inner sealing joint 2 protrudes from the inner wall of the main joint 1 to form a pressure-bearing surface 22.

[0043] like Figure 2 As shown, the top end of the inner sealing joint 2 is slidably connected to the interior of the main joint 1, and the outer wall of the inner sealing joint 2 is slidably and sealingly connected to the inner wall of the main joint 1. The function of the pressure-bearing surface 22 is that when fracturing fluid is injected into the pipe, the fracturing fluid forms a downward pressure on the pressure-bearing surface 22, which in turn pushes the inner sealing joint 2 to exert a downward force. Since the inner sealing joint 2 is threadedly connected to the hanger 4, and the hanger 4 is threadedly connected to the insertion pipe 5, that is, the inner sealing joint 2, the hanger 4, and the insertion pipe 5 form an integral structure. After the pressure is applied to the pressure-bearing surface 22 at the top end of the inner sealing joint 2, the force is transmitted to the hanger 4, which facilitates the tight contact of the hanger 4 with the top end of the hanger 3, thereby limiting the axial movement of the insertion pipe 5 and ensuring high sealing reliability. Preferably, the inner sealing joint 2 is made of 42CrMo material.

[0044] Optionally, the pressure-bearing surface 22 is inclined downward along the outer wall of the inner sealing joint 2 toward the inner wall.

[0045] like Figure 2 As shown, the pressure-bearing surface 22 is an inclined plane relative to the axis of the inner sealing joint 2. The annular pressure-bearing surface 22 with a constricted structure is formed at the top of the inner sealing joint 2, which can guide the fracturing fluid, reduce pressure fluctuations caused by sudden changes in the pipe wall, and prevent the inner sealing joint 2 from being subjected to a large instantaneous impact, thus affecting the sealing performance.

[0046] Optionally, a sliding surface is formed between the top end face of the hook connector 4 and the bottom end face of the slip 3, and the sliding surface slopes downward from the inner wall to the outer wall of the hook connector 4.

[0047] like Figure 3 and Figure 4 As shown, the top end face of the hook connector 4 has a first inclined surface 41, and the bottom end face of the slip 3 has a second inclined surface 31. The first inclined surface 41 and the second inclined surface 31 abut against each other to form a sliding surface. When the main connector 1 is subjected to force, it pushes the slip 3 downward. During the opening process, the slip 3 slides downward along the sliding surface to open, realizing the transition from the lowered state to the working state. It can be understood that setting the sliding surface is conducive to the smooth opening and anchoring of the slip 3, and also has a guiding effect on the opening direction of the slip 3. It should be noted that the sliding length formed between the first inclined surface 41 and the second inclined surface 31 must ensure that when the slip 3 achieves the anchored working state, the slip 3 can still abut against the top of the hook connector 4 for easy retrieval.

[0048] Optionally, the outer diameter of the hook connector 4 is larger than the outer diameter of the hanger, and the bottom end face of the hook connector 4 can abut against the top end face of the hanger.

[0049] like Figure 2 and Figure 3As shown, the two ends of the hook connector 4 are threaded to the inner sealing connector 2 and the insertion tube 5, respectively. The outer diameter of the hook connector 4 is larger than the outer diameter of the insertion tube 5 and larger than the outer diameter of the hanger, which facilitates the stable setting of the bottom end face of the hook connector 4. Generally, the bottom end of the hook connector 4 abuts against the top of the suspension cylinder of the hanger, and the outer wall of the insertion tube 5 fits and seals with the inner wall of the suspension cylinder.

[0050] Optionally, a plurality of first sealing elements 21 are provided axially at intervals on the outer wall of the top end of the inner sealing joint 2. The first sealing elements 21 can press and seal between the outer wall of the inner sealing joint 2 and the inner wall of the main joint 1.

[0051] like Figure 2 In this embodiment, multiple annular grooves are machined on the outer wall of the top end of the inner sealing joint 2. The first sealing element 21 can be installed and positioned within the corresponding grooves. Simultaneously, the outer diameter of the first sealing element 21 is larger than the groove depth, thereby enabling the first sealing element 21 to achieve a sliding seal between the main joint 1 and the inner sealing joint 2. Preferably, the first sealing element 21 is a fluororubber ring, which has the advantages of a wide operating temperature range and good corrosion resistance.

[0052] Optionally, a plurality of second seals 51 are provided at axial intervals on the outer wall of the insertion tube 5, and the second seals 51 are vulcanized on the outer wall of the insertion tube 5.

[0053] like Figure 2 As shown, the insertion tube 5 typically adopts a segmented structure. One segment, equipped with the second sealing element 51, is separately vulcanized to form a sealing structure and then threadedly connected to the other segment. The second sealing element 51 is located on the outer wall of the insertion tube 5 near its bottom end, and a seal is achieved between the second sealing element 51 and the inner wall of the suspension cylinder of the hanger. Multiple second sealing elements 51 are spaced apart along the axial direction of the insertion tube 5 to form sealing segments of a certain length to meet sealing requirements.

[0054] Optionally, the low-temperature resistant self-sealing anchoring reconnection device also includes a connecting pipe 6, with the two ends of the connecting pipe 6 connected to the main connector 1 and the slip 3 respectively, and the inner sealing connector 2 slidably connected inside the connecting pipe 6.

[0055] like Figure 3To facilitate the installation of the inner sealing joint 2 and meet its sliding distance requirements, a connecting pipe 6 is threadedly connected to the bottom end of the main joint 1 for installing the inner sealing joint 2. The top end of the connecting pipe 6 has an internal thread, and the bottom end of the main joint 1 has an external thread. The main joint 1 and the connecting pipe 6 are threaded together, making the connection convenient and ensuring a good seal. A slip 3 is located at the bottom end of the connecting pipe 6, facilitating its installation and replacement. Simultaneously, the connecting pipe 6 allows for adjustment of the positions of the main joint 1 and the inner sealing joint 2, ensuring that the sliding of the inner sealing joint 2 meets the limiting requirements, preventing it from slipping out of the connecting pipe 6 or from excessive sliding and causing damage. It should be noted that all internal or external threads are high-strength, tensile-resistant, and internal-pressure-resistant standard or non-standard threads to ensure connection strength.

[0056] Optionally, the bottom end of the main connector 1 and the top end of the inner sealing connector 2 are both located inside the connecting pipe 6, and the initial distance between the top end of the inner sealing connector 2 and the bottom end of the main connector 1 is not less than the distance difference before and after the slip 3 opens.

[0057] like Figure 3 As shown, after the main connector 1 is subjected to downward pressure, it moves downward relative to the inner sealing connector 2. Since the inner sealing connector 2 is fixed in position by abutting the top of the hanger through the hook connector 4, the top of the inner sealing connector 2 can limit the excessive downward sliding of the main connector 1 and prevent damage to the slips 3. It can be understood that in the lowered state, the distance between the top of the inner sealing connector 2 and the bottom of the main connector 1 must meet the distance requirement for the slips 3 to descend to a sufficient distance to open and anchor, and the automatic retraction function when lifting the slips 3 after anchoring is also considered. The process of the main connector 1 driving the slips 3 to move downward to anchor realizes a retractable sealing structure, which can achieve the functions of opening and retraction of the slips 3, and also achieve the re-insertion sealing of the insertion tube 5 without being affected by segmented fracturing, which is especially suitable for repeated fracturing operations in the process of old well renovation.

[0058] The low-temperature resistant self-sealing anchoring reconnection device provided by this invention is used in the following re-insertion fracturing operation process:

[0059] First, the low-temperature self-sealing anchoring reconnection device is set at the bottom of the reconnection sleeve. Lubricating oil is applied to the outer wall of the insertion tube 5 and its second sealing element 51. After the insertion tube 5 is lowered into the reconnection sleeve to a certain distance from the top of the hanger, the suspension cylinder of the hanger is flushed.

[0060] Then, insert the insertion tube 5 into the suspension cylinder so that the bottom end of the hanger 4 sits on the top of the hanger. Based on the sleeve hanger, make an adjustable sleeve, and connect the two ends of the adjustable sleeve to the sleeve hanger and the return sleeve, respectively.

[0061] Then lower the extended sleeve to the bottom and apply 10-15 tons of pressure. The slip 3 opens, and the main joint 1, the inner sealing joint 2, and each pipe section remain centered and under pressure.

[0062] Because the inner diameters of the main connector 1 and the inner sealing connector 2 are different, during the fracturing fluid pressure test, under the pressure difference between the top of the inner sealing connector 2 and the bottom of the insertion tube 5, the inner sealing connector 2, the hanger connector and the insertion tube 5 are always in a downward pressure state, thereby ensuring that the slip 3 is in an open state.

[0063] Finally, the pumping bridge plug fracturing operation: During the fracturing operation, the slip 3 is always in an open state to ensure that the tubing string is centered; during the fracturing process, because the top of the inner sealing joint 2 is subjected to downward pressure, even if the pressure fluctuates, it will not affect the sealing of the bottom part of the insertion tube 5. Therefore, the section of the insertion tube 5 equipped with the second sealing element 51 is always in a fixed state, without moving up or down or creeping, ensuring the sealing reliability of the insertion tube 5.

[0064] The low-temperature self-sealing anchoring reconnection device of the present invention has high compressive strength and a sealing performance of 70MPa. It is especially suitable for reconnection of φ114.3mm large-size casing in the re-construction of 5-1 / 2" small wellbore, which can reduce the construction risk of segmented fracturing and improve the efficiency of repeated segmented fracturing construction.

[0065] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A low-temperature resistant self-sealing anchoring reconnection device, characterized in that, include: Main connector (1); An inner sealing joint (2) is provided, the top end of which is inserted into the bottom end of the main joint (1) and is slidably and sealingly connected to the main joint (1); the inner wall of the inner sealing joint (2) protrudes from the inner wall of the main joint (1) to form a pressure-bearing surface (22). The slip (3) is located on the outside of the inner sealing joint (2) and is fixedly connected to the bottom end of the main joint (1); The top end of the hook connector (4) is provided with an internal thread to connect the inner sealing connector (2), the bottom end of the slip (3) abuts against the top end of the hook connector (4), the outer diameter of the hook connector (4) is larger than the outer diameter of the hanger, and the bottom end of the hook connector (4) can sit on the top end of the hanger. An insertion tube (5) is connected to the internal thread at the bottom end of the hook connector (4), and the insertion tube (5) can be inserted into the hanger; the outer diameter of the hook connector (4) is larger than the outer diameter of the insertion tube (5); a plurality of second seals (51) are provided axially spaced on the outer wall of the insertion tube (5), and the second seals (51) are vulcanized on the outer wall of the insertion tube (5); the insertion tube (5) adopts a segmented structure, and one segment with the second seals (51) is vulcanized separately to form a sealing structure, and then threadedly connected to the other segment; A connecting pipe (6) is provided, with its two ends connected to the main connector (1) and the slip (3) respectively. The inner sealing connector (2) is slidably connected inside the connecting pipe (6). The bottom end of the main connector (1) and the top end of the inner sealing connector (2) are both located inside the connecting pipe (6). The initial distance between the top end of the inner sealing connector (2) and the bottom end of the main connector (1) is not less than the distance difference before and after the slip (3) is opened. The top end of the inner sealing connector (2) can limit the main connector (1) from sliding down excessively and from damaging the slip (3).

2. The low-temperature resistant self-sealing anchoring reconnection device according to claim 1, characterized in that, The pressure-bearing surface (22) is inclined downward along the outer wall of the inner sealing joint (2) toward the inner wall.

3. The low-temperature resistant self-sealing anchoring reconnection device according to claim 1, characterized in that, A sliding surface is formed between the top end face of the hook connector (4) and the bottom end face of the clasp (3), and the sliding surface slopes downward from the inner wall of the hook connector (4) towards the outer wall.

4. The low-temperature resistant self-sealing anchoring reconnection device according to claim 1, characterized in that, The top outer wall of the inner sealing joint (2) is provided with a plurality of first sealing elements (21) spaced apart along the axial direction. The first sealing elements (21) can press and seal between the outer wall of the inner sealing joint (2) and the inner wall of the main joint (1).

5. The low-temperature resistant self-sealing anchoring reconnection device according to claim 4, characterized in that, The first sealing element (21) is a fluororubber ring.

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