Leakage-proof valve of ocean producing well

Abstract

The anti-leakage valve comprises a valve seat body, an outer sleeve semi-sealed gate valve body and an embedded full-sealed gate valve body, the outer sleeve semi-sealed gate valve body and the embedded full-sealed gate valve body are symmetrically arranged, hydraulic connecting mechanisms connected with a hydraulic control system are symmetrically arranged outside the valve seat body, and each hydraulic connecting mechanism comprises a hydraulic oil cylinder body, an inner piston rod and an outer piston cylinder; an inner piston block is fixedly connected to the end, away from the outer sleeve semi-sealed gate valve body, of the inner piston rod, an outer piston sleeve is fixedly connected to the end, away from the embedded full-sealed gate valve body, of the outer piston cylinder, and a self-locking piece A and a self-locking piece B are arranged at the top of the outer sleeve semi-sealed gate valve body and the top of the embedded full-sealed gate valve body correspondingly. Hydraulic oil is provided for the interior of the well shut-in oil cavity through the hydraulic control system, so that the semi-sealing effect of the outer sleeve semi-sealing gate valve body on a well mouth and the full-sealing effect of the embedded full-sealing gate valve body on the well mouth can be achieved; and when the wellhead is semi-sealed or fully-sealed, the externally-sleeved semi-sealed gate valve body and the internally-embedded fully-sealed gate valve body can be quickly locked.

Description

Technical Field

[0001] The invention relates to the technical field of oil well valves, and in particular to an anti-leakage valve for an offshore oil well. Background Art

[0002] Offshore drilling platforms can build oil well bodies on the seabed through the use of drill pipes. After the well bodies of offshore oil wells are built, underwater blowout preventers need to be installed on the top of the wellhead to prevent blowouts. Otherwise, once a blowout occurs, it will not only cause an explosion on the offshore drilling platform, but also seriously pollute the marine ecological environment. That is, the installation of underwater blowout preventers is very necessary to ensure the safe development of submarine oil and gas resources and the protection of the marine ecological environment. The underwater blowout preventer is mainly composed of a shell, a gate assembly, a side door, a gate core, etc. Its switch is controlled by the hydraulic oil provided by the control device. The control device needs to prepare and store enough pressure oil in advance, and control the flow direction of the pressure oil at the same time, so that the underwater blowout preventer can quickly switch.

[0003] After searching, the invention patent with Chinese patent number CN 114893143 A discloses a marine oil well wellhead device, including a shell, a vertical groove is opened in the middle position inside the shell, a slide groove is also opened inside the shell, a gate plate is movably installed in the slide groove, a hydraulic rod is fixedly installed on the side of the gate plate, an air cavity is opened inside the gate plate, a push plate is sealingly and movably installed in the air cavity, a connecting rod is fixedly installed on the side of the push plate, an air guide groove is opened inside the gate plate, an air film is fixedly installed on the side of the gate plate, an air guide pipe is fixedly installed on the side of the push plate, the air guide pipe connects the outer cavity and the air guide groove, and a sealing block is installed on the side of the gate plate close to the vertical groove. Compared with the existing technology, the invention patent with patent number CN 114893143 A can increase the friction between the gate and the pipe string through the setting of the air film and the sealing block to offset part of the upward impact of the oil on the gate, that is, reduce the probability of deformation of the gate, so that the oil is not easy to spray out. At the same time, the setting of the air film can improve the sealing effect of the gate on the pipe string and the shell.

[0004] The above-mentioned marine oil well wellhead device can achieve the effect of semi-sealing the wellhead by clamping the tubing to seal the tubing and the annular space in the well. However, if the wellhead needs to be fully sealed, a fully sealed gate plate needs to be installed above it. The two independent hydraulic control systems required for the semi-sealed gate plate and the fully sealed gate plate will undoubtedly increase the cost of the device. After achieving the effect of semi-sealing or fully sealing the wellhead, it is necessary to control the underwater manipulator to lock the semi-sealed gate plate or the fully sealed gate plate, and the control of the underwater manipulator requires a certain amount of time. Therefore, a leak-proof valve for marine oil wells is needed, which can share the same hydraulic control system to semi-seal and fully seal the wellhead and can quickly lock the semi-sealed gate plate or the fully sealed gate plate. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings in the prior art that two independent hydraulic control systems are required for half-closed gate plates and fully-closed gate plates, which increases the cost of the device, and it takes a certain amount of time to control the underwater manipulator to lock the half-closed gate plate or the fully-closed gate plate, and to propose a leakage-proof valve for marine oil wells.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: A leakage-proof valve for an offshore oil production well, comprising a valve seat body installed at the top of a wellhead, and an outer sleeve semi-enclosed gate valve body and an inner sleeve fully-enclosed gate valve body symmetrically arranged on the outside of a pipe column, wherein a receiving slot is provided in the middle of the valve seat body, the outer sleeve semi-enclosed gate valve body is slidably connected to the inside of the receiving slot, a sealing slide groove is provided in the middle of the outer sleeve semi-enclosed gate valve body, the inner sleeve fully-enclosed gate valve body is slidably connected to the inside of the sealing slide groove, a hydraulic connection mechanism connected to a hydraulic control system is symmetrically arranged on the outside of the valve seat body, the hydraulic connection mechanism comprises a hydraulic cylinder body fixedly connected to the outside of the valve seat body, and an inner piston fixedly connected to the outer side of the outer sleeve semi-enclosed gate valve body The cam is an outer piston cylinder which is fixedly connected to the outer side of the inner fully enclosed gate valve body, the inner piston rod is fixedly connected to an inner piston block located inside the outer piston cylinder at one end away from the outer semi-enclosed gate valve body, the outer piston cylinder is fixedly connected to an outer piston sleeve located inside the hydraulic cylinder body at one end away from the inner fully enclosed gate valve body, the outer piston sleeve divides the inner cavity space of the hydraulic cylinder body into a shut-in oil cavity and a well-opening oil cavity; by providing hydraulic oil to the shut-in oil cavity through a hydraulic control system, the outer semi-enclosed gate valve body can be first pushed to hold the outer side of the pipe string, and then the inner fully enclosed gate valve body can be pushed to press against the outer side of the pipe string to achieve a semi-sealed effect and a fully sealed effect on the wellhead.

[0007] A self-locking part A and a self-locking part B for self-locking are respectively provided on the top of the outer sleeve semi-enclosed gate valve body and the inner sleeve fully-enclosed gate valve body, and a rectangular lock groove is symmetrically fixedly connected to the top of the accommodating empty groove, and a blocking reset block is provided inside the rectangular lock groove, and the self-locking part A and the self-locking part B respectively include a rectangular lock block and a cylindrical lock block that can be reset by the blocking reset block; the rectangular lock block enters the interior of the rectangular lock groove and presses against the blocking reset block to achieve the self-locking effect of the outer sleeve semi-enclosed gate valve body, and the cylindrical lock block enters the interior of the cylindrical lock groove and presses against the rectangular lock block to achieve the self-locking effect of the inner sleeve fully-enclosed gate valve body.

[0008] The above technical solution further includes: The inner sides of the outer sleeve semi-enclosed gate valve body and the embedded fully-enclosed gate valve body are both provided with sealing rubber layers, and the upper and lower sides of the outer sleeve semi-enclosed gate valve body are both provided with sealing rubber rings; the sealing rubber layer can ensure the sealing between the outer sleeve semi-enclosed gate valve body, the embedded fully-enclosed gate valve body and the pipe column; the sealing rubber ring can ensure the sealing between the outer sleeve semi-enclosed gate valve body and the accommodating empty groove.

[0009] The inner piston rod is located outside the outer piston cylinder, and an opening that passes through the outer semi-enclosed gate valve body is symmetrically provided on the outer side of one end of the outer piston cylinder close to the embedded fully enclosed gate valve body, and a sealing shaft ring embedded in the valve seat body is provided on the outside of the outer piston cylinder; the setting of the opening can allow sliding between the outer piston cylinder and the outer semi-enclosed gate valve body and the existence of the inner piston rod.

[0010] An oil inlet pipe and an oil return pipe connected to the shut-in oil chamber and the well-opening oil chamber are symmetrically arranged on the outside of the hydraulic oil cylinder body, and a one-way valve and a switch valve are respectively installed on the outside of the oil inlet pipe and the oil return pipe. Semi-sealing and full sealing of the wellhead can be achieved by supplying hydraulic oil to the shut-in oil chamber through the oil inlet pipe, and the well can be opened by supplying hydraulic oil to the well-opening oil chamber through the oil inlet pipe.

[0011] The oil inlet pipeline outside the well opening oil cavity is composed of a pipeline A extending horizontally to the inside of the valve seat body and a pipeline B extending vertically to the outside of the valve seat body. The pipeline A and the pipeline B are respectively connected to the top and side of the rectangular lock groove.

[0012] The interior of the pipeline B is fixedly connected to a limiting frame, the interior of the limiting frame is slidably connected to a connecting rod fixedly connected to the blocking and resetting block, and the top of the connecting rod is fixedly connected to a limiting plate.

[0013] The self-locking component A also includes a rectangular slide groove opened on the top of the outer sleeve semi-closed gate valve body, the rectangular locking block is slidably connected to the inside of the rectangular slide groove, and a locking spring A is fixedly connected between the rectangular locking block and the rectangular slide groove; when the outer sleeve semi-closed gate valve body clamps the pipe column, the rectangular locking block can enter the inside of the rectangular lock groove and press against the sealing reset block to achieve a self-locking effect.

[0014] The self-locking part B also includes a cylindrical slide groove opened on the top of the embedded fully enclosed gate valve body and a cylindrical lock groove connected to the rectangular slide groove. The cylindrical locking block is slidably connected to the inside of the cylindrical lock groove. A locking spring B is fixedly connected between the cylindrical lock block and the cylindrical lock groove. When the embedded fully enclosed gate valve body presses the pipe column, the cylindrical lock block can enter the inside of the cylindrical lock groove and press against the rectangular lock block to achieve a self-locking effect.

[0015] The present invention has the following beneficial effects: 1. The present invention provides hydraulic oil to the inside of the shut-in oil chamber through a hydraulic control system, so as to first push the outer sleeve semi-sealed gate valve body and the inner embedded fully-sealed gate valve body to move synchronously so that the outer sleeve semi-sealed gate valve body is tightly held on the outside of the pipe string, and then push the inner embedded fully-sealed gate valve body so that the inner embedded fully-sealed gate valve body is pressed against the outside of the pipe string. The outer sleeve semi-sealed gate valve body is tightly held on the outside of the pipe string, which can seal the annular space between the pipe string and the valve seat body to prevent leakage and prevent the pipe string from being forced to move upward and affect oil production. The inner embedded fully-sealed gate valve body is pressed against the outside of the pipe string and cooperates with the semi-sealing effect of the outer sleeve semi-sealed gate valve body to achieve a fully sealed effect on the wellhead. That is, the present invention shares the same set of hydraulic control systems to achieve a semi-sealed effect of the outer sleeve semi-sealed gate valve body on the wellhead and a fully sealed effect of the inner embedded fully-sealed gate valve body on the wellhead.

[0016] 2. The present invention provides hydraulic oil to the inside of the shut-in oil chamber through a hydraulic control system so that the outer sleeve semi-sealed gate valve body is tightly held on the outside of the pipe string and the inner sleeve fully-sealed gate valve body is pressed against the outside of the pipe string, the rectangular locking block can enter the inside of the rectangular locking groove and press against the blocking reset block to achieve the self-locking effect of the outer sleeve semi-sealed gate valve body, the cylindrical locking block can enter the inside of the cylindrical locking groove and press against the rectangular locking block to achieve the self-locking effect of the inner sleeve fully-sealed gate valve body, and the hydraulic control system provides hydraulic oil to the inside of the oil inlet pipeline outside the well opening oil chamber so that the outer sleeve semi-sealed gate valve body and the inner sleeve fully-sealed gate valve body are reset, the rectangular locking block and the cylindrical locking block can enter the inside of the rectangular locking groove and the cylindrical locking groove to release the self-locking effect of the outer sleeve semi-sealed gate valve body and the inner sleeve fully-sealed gate valve body, that is, the present invention can quickly lock the outer sleeve semi-sealed gate valve body and the inner sleeve fully-sealed gate valve body. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of a first side cross-sectional structure of an anti-leakage valve for an offshore oil well proposed by the present invention; Figure 2 A second side cross-sectional structural schematic diagram of an anti-leakage valve for an offshore oil well proposed by the present invention; Figure 3 for Figure 2 A schematic diagram of the structure enlargement in the middle; Figure 4 It is a first structural schematic diagram of the outer jacket semi-enclosed gate valve body and the inner jacket fully-enclosed gate valve body in the present invention; Figure 5 It is a second structural schematic diagram of the outer sleeve semi-enclosed gate valve body and the inner sleeve fully-enclosed gate valve body in the present invention; Figure 6 This is a schematic diagram of the structure of the semi-sealed wellhead of the present invention; Figure 7 for Figure 6 A magnified schematic diagram of the structure at B in the middle; Figure 8 This is a schematic diagram of the structure of the present invention for fully sealing the wellhead; Fig. 9 for Figure 8 A magnified schematic diagram of the structure at C in the middle; Fig.10 This is a schematic diagram of the connection structure of an anti-leakage valve for an offshore oil well proposed by the present invention.

[0018] In the figure: 1, wellhead; 2, valve seat body; 3, pipe column; 4, outer semi-enclosed gate valve body; 5, embedded fully enclosed gate valve body; 6, accommodating empty groove; 7, sealing slide groove; 8, hydraulic control system; 9, hydraulic connection mechanism; 901, hydraulic cylinder body; 902, inner piston rod; 903, outer piston cylinder; 904, inner piston block; 905, outer piston sleeve; 906, shut-in oil chamber; 907, open-well oil chamber; 908, opening; 909, sealing shaft ring; 910, oil inlet pipeline; 9101, pipeline A; 9 102. Pipeline B; 911. Oil return pipeline; 912. One-way valve; 913. Switch valve; 10. Self-locking part A; 101. Rectangular locking block; 102. Rectangular slide; 103. Locking spring A; 11. Self-locking part B; 111. Cylindrical locking block; 112. Cylindrical slide; 113. Cylindrical locking groove; 114. Locking spring B; 12. Rectangular locking groove; 13. Blocking and resetting block; 14. Sealing rubber layer; 15. Sealing rubber ring; 16. Limiting frame; 17. Connecting rod; 18. Limiting plate. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Embodiment 1 like Figure 1-Figure 2 , Figure 4-Figure 6 , Figure 8 and Fig.10As shown, the present invention proposes an anti-leakage valve for an offshore oil production well, comprising a valve seat body 2 installed at the top of a wellhead 1, and an outer sleeve semi-enclosed gate valve body 4 and an inner sleeve fully-enclosed gate valve body 5 symmetrically arranged outside a pipe column 3, the outer sleeve semi-enclosed gate valve body 4 and the inner sleeve fully-enclosed gate valve body 5 are both located above the wellhead 1, a receiving slot 6 is opened in the middle of the valve seat body 2, the outer sleeve semi-enclosed gate valve body 4 is slidably connected to the inside of the receiving slot 6, and sealing rubber rings 15 are arranged on the upper and lower sides of the outer sleeve semi-enclosed gate valve body 4, and the sealing rubber rings 15 are arranged on the upper and lower sides of the outer sleeve semi-enclosed gate valve body 4. The rubber ring 15 can ensure the sealing between the outer jacket semi-sealed gate valve body 4 and the accommodating empty groove 6. A sealing slide groove 7 is provided in the middle of the outer jacket semi-sealed gate valve body 4. The embedded fully sealed gate valve body 5 is slidably connected inside the sealing slide groove 7. The outer jacket semi-sealed gate valve body 4 and the sealing slide groove 7 are sealed and slidably connected. The inner sides of the outer jacket semi-sealed gate valve body 4 and the embedded fully sealed gate valve body 5 are both provided with a sealing rubber layer 14. The sealing rubber layer 14 can ensure the sealing between the outer jacket semi-sealed gate valve body 4, the embedded fully sealed gate valve body 5 and the pipe column 3. The outside of the valve seat body 2 is symmetrically provided with a hydraulic connection mechanism 9 connected to the hydraulic control system 8. As a prior art, the hydraulic control system 8 can provide hydraulic oil to the inside of the oil inlet pipeline 910. The hydraulic connection mechanism 9 includes a hydraulic oil cylinder body 901 fixedly connected to the outside of the valve seat body 2, an inner piston rod 902 fixedly connected to the outside of the outer sleeve semi-enclosed gate valve body 4, and an outer piston cylinder 903 fixedly connected to the outside of the embedded fully enclosed gate valve body 5. The outside of the hydraulic oil cylinder body 901 is symmetrically provided with an oil inlet pipeline 910 and an oil return pipeline 911 connected to the well-closing oil chamber 906 and the well-opening oil chamber 907. A one-way valve 912 and a switch valve 913 are respectively installed on the outside of the oil inlet pipeline 910 and the oil return pipeline 911. Both the one-way valve 912 and the switch valve 913 are controlled by the hydraulic control system 8. The oil return pipeline 911 can be recovered to the hydraulic control system 8 through a recovery pipeline for utilization; The inner piston rod 902 is located outside the outer piston cylinder 903, and the end of the inner piston rod 902 away from the outer sleeve semi-closed gate valve body 4 is fixedly connected to the inner piston block 904 located inside the outer piston cylinder 903. The outer piston cylinder 903 is provided with a sealing shaft ring 909 embedded in the valve seat body 2. The sealing shaft ring 909 can ensure the sealing between the outer piston cylinder 903 and the hydraulic cylinder body 901. The outer end of the outer piston cylinder 903 close to the embedded fully sealed gate valve body 5 is symmetrically provided with an opening 908 that passes through the outer sleeve semi-closed gate valve body 4. The setting of the opening 908 can allow the outer Due to the sliding between the piston cylinder 903 and the outer semi-enclosed gate valve body 4 and the existence of the inner piston rod 902, the end of the outer piston cylinder 903 away from the embedded fully-enclosed gate valve body 5 is fixedly connected to the outer piston sleeve 905 located inside the hydraulic cylinder body 901. The outer piston sleeve 905 divides the inner cavity space of the hydraulic cylinder body 901 into a shut-in oil chamber 906 and an opening oil chamber 907. The semi-sealing and full-sealing of the wellhead can be achieved by supplying hydraulic oil to the inside of the shut-in oil chamber 906 through the oil inlet pipe 910, and the well can be opened by supplying hydraulic oil to the inside of the opening oil chamber 907 through the oil inlet pipe 910.

[0021] In this embodiment: when the offshore oil production is carried out through the tubing string 3, the hydraulic control system 8 can be used to provide hydraulic oil to the inside of the oil inlet pipeline 910 outside the well-closing oil chamber 906, and the switch valve 913 outside the well-opening oil chamber 907 can be opened. The hydraulic oil entering the oil inlet pipeline 910 will push the inner piston block 904 and the outer piston sleeve 905 to move inward, so that the inner piston rod 902 and the outer piston cylinder 903 drive the outer sleeve semi-sealed gate valve body 4 and the embedded fully sealed gate valve body 5 to move in the direction close to the tubing string 3, until the outer sleeve semi-sealed gate valve body 4 drives the inner sealing rubber layer 14 to hold the outer side of the tubing string 3 tightly, and the supply of hydraulic oil to the inside of the oil inlet pipeline 910 can be stopped. At this time, the symmetrical outer sleeve semi-sealed gate valve body 4 is tightly held on the outer side of the tubing string 3 to seal the annular space between the tubing string 3 and the valve seat body 2, and can stabilize the position of the tubing string 3, that is, the wellhead 1 is semi-sealed to prevent leakage, and the tubing string 3 can be prevented from being forced upward to affect oil production. If a blowout occurs during the process of offshore oil production in the tubing string 3, hydraulic oil will be immediately supplied to the oil inlet pipeline 910 outside the shut-in oil chamber 906 through the hydraulic control system 8. Since the outer sleeve semi-closed gate valve body 4 has been tightly held on the outside of the tubing string 3, that is, the inner piston block 904 and the inner piston rod 902 can no longer move inward, the hydraulic oil entering the oil inlet pipeline 910 will push the outer piston sleeve 905 to move inward, so that the outer piston cylinder 903 drives the embedded full-closed gate The valve body 5 slides inside the sealing groove 7 and moves toward the direction close to the pipe column 3 until the embedded fully sealed gate valve body 5 drives the sealing rubber layer 14 inside thereof to press against the outside of the pipe column 3, and the supply of hydraulic oil to the inside of the oil inlet pipeline 910 can be stopped. At this time, the symmetrical embedded fully sealed gate valve body 5 is pressed against the outside of the pipe column 3 to seal the pipe column 3, and cooperates with the semi-sealing effect of the outer sleeve semi-sealed gate valve body 4 to achieve a fully sealed effect on the wellhead 1, that is, the wellhead 1 can be fully sealed to prevent the oil mixture from leaking upward; After the blowout phenomenon ends, hydraulic oil can be supplied to the oil inlet pipeline 910 outside the well opening oil chamber 907 through the hydraulic control system 8, and the switch valve 913 outside the well opening oil chamber 906 can be opened. The hydraulic oil entering the well opening oil chamber 907 will push the outer piston sleeve 905 to move outward, so that the outer piston cylinder 903 drives the embedded fully sealed gate valve body 5 to slide inside the sealing slide groove 7 and move in the direction away from the pipe column 3. When the embedded fully sealed gate valve body 5 slides to contact the inner side wall of the outer jacket semi-sealed gate valve body 4, the embedded fully sealed gate valve body 5 will drive the outer jacket semi-sealed gate valve body 4 to move together in the direction away from the pipe column 3, until the outer jacket semi-sealed gate valve body 4 and the embedded fully sealed gate valve body 5 are reset, and the supply of hydraulic oil to the oil inlet pipeline 910 can be stopped. The anti-leakage valve of the present marine oil production well provides hydraulic oil to the inside of the shut-in oil chamber 906 through the hydraulic control system 8, which can first push the outer semi-sealed gate valve body 4 and the embedded fully-sealed gate valve body 5 to move synchronously so that the outer semi-sealed gate valve body 4 is tightly held on the outside of the pipe column 3, and then push the embedded fully-sealed gate valve body 5 so that the embedded fully-sealed gate valve body 5 is pressed against the outside of the pipe column 3. The outer semi-sealed gate valve body 4 is tightly held on the outside of the pipe column 3, which can seal the annular space between the pipe column 3 and the valve seat body 2 to prevent leakage and prevent the pipe column 3 from being forced upward to affect oil production. The embedded fully-sealed gate valve body 5 is pressed against the outside of the pipe column 3 and cooperates with the semi-sealing effect of the outer semi-sealed gate valve body 4 to achieve a fully sealed effect on the wellhead 1. That is, the anti-leakage valve of the present marine oil production well shares the same set of hydraulic control systems 8 to achieve the semi-sealing effect of the outer semi-sealed gate valve body 4 on the wellhead 1 and the fully sealed effect of the embedded fully-sealed gate valve body 5 on the wellhead 1.

[0022] Embodiment 2 like Figure 1-Figure 3 and Figure 6-Figure 9As shown, based on the first embodiment, the top of the accommodating empty groove 6 is symmetrically fixedly connected with a rectangular lock groove 12, and a plugging and resetting block 13 is arranged inside the rectangular lock groove 12. The plugging and resetting block 13 is sealed and slidably connected with the rectangular lock groove 12. The oil inlet pipeline 910 outside the well opening oil chamber 907 is composed of a pipeline A9101 extending horizontally to the inside of the valve seat body 2 and a pipeline B9102 extending vertically to the outside of the valve seat body 2. The pipeline A9101 and the pipeline B9102 are connected to the top and side of the rectangular lock groove 12 respectively. The plugging and resetting block 13 can be plugged at the bottom of the pipe B9102, and the hydraulic oil inside the pipe B9102 can enter the inside of the pipe A9101 through the rectangular lock groove 12 and the plugging and resetting block 13. The inside of the pipe B9102 is fixedly connected to the limiting frame 16, and the inside of the limiting frame 16 is slidably connected with a connecting rod 17 fixedly connected to the plugging and resetting block 13, and the top of the connecting rod 17 is fixedly connected to the limiting plate 18, and the plugging and resetting block 13, the connecting rod 17 and the limiting plate 18 can move synchronously; The tops of the outer jacket semi-enclosed gate valve body 4 and the inner embedded fully enclosed gate valve body 5 are respectively provided with a self-locking self-locking member A10 and a self-locking member B11, the self-locking member A10 and the self-locking member B11 respectively include a rectangular lock block 101 and a cylindrical lock block 111 that can be reset by a blocking reset block 13, the sides of the rectangular lock block 101 and the blocking reset block 13 that are close to each other are both arc sides, and the top side of the cylindrical lock block 111 is arc-shaped to assist it to disengage from the cylindrical slide groove 112; The self-locking member A10 also includes a rectangular slide groove 102 opened on the top of the outer sleeve semi-closed gate valve body 4, a rectangular locking block 101 is slidably connected inside the rectangular slide groove 102, and a locking spring A103 is fixedly connected between the rectangular locking block 101 and the rectangular slide groove 102. The locking spring A103 is compressed in the initial state. When the outer sleeve semi-closed gate valve body 4 holds the pipe column 3 tightly, the rectangular locking block 101 can enter the interior of the rectangular locking groove 12 and press against the blocking reset block 13 to achieve a self-locking effect; The self-locking part B11 also includes a cylindrical slide groove 112 opened on the top of the embedded fully enclosed gate valve body 5 and a cylindrical locking groove 113 connected to the rectangular slide groove 102. The cylindrical locking block 111 is slidably connected to the inside of the cylindrical locking groove 113. A locking spring B114 is fixedly connected between the cylindrical locking block 111 and the cylindrical locking groove 113. The locking spring B114 is compressed in the initial state. When the embedded fully enclosed gate valve body 5 presses the pipe column 3, the cylindrical locking block 111 can enter the inside of the cylindrical locking groove 113 and press against the rectangular locking block 101 to achieve a self-locking effect.

[0023] In this embodiment: Figure 6 and Figure 7As shown, when the outer sleeve semi-closed gate valve body 4 is tightly held on the outside of the pipe column 3, the rectangular locking block 101 moves with the outer sleeve semi-closed gate valve body 4 to align with the rectangular locking groove 12, and the compressed locking spring A103 immediately drives the rectangular locking block 101 upward into the interior of the rectangular locking groove 12 and presses against the blocking reset block 13, so that the blocking reset block 13 is blocked at the bottom of the pipeline B9102, so that the self-locking effect of the outer sleeve semi-closed gate valve body 4 can be achieved; like Figure 8 and Fig. 9 As shown, when the embedded fully enclosed gate valve body 5 is pressed against the outside of the pipe column 3, the cylindrical locking block 111 moves with the embedded fully enclosed gate valve body 5 to align with the cylindrical locking groove 113, and the compressed locking spring B114 immediately drives the cylindrical locking block 111 upward into the cylindrical locking groove 113 and presses against the rectangular locking block 101, so that the self-locking effect of the embedded fully enclosed gate valve body 5 can be achieved; When hydraulic oil is supplied to the oil inlet pipe 910 outside the well opening oil chamber 907 through the hydraulic control system 8 to reset the outer semi-enclosed gate valve body 4 and the inner fully-enclosed gate valve body 5, the hydraulic oil entering the pipe B9102 will press down the blocking reset block 13, so that the blocking reset block 13 presses down the rectangular lock block 101 and the cylindrical lock block 111. The blocking reset block 13 under the hydraulic oil pressure presses down the rectangular lock block 101 into the inside of the rectangular lock groove 12. The pressed rectangular lock block 101 entering the inside of the rectangular lock groove 12 presses down the cylindrical lock block 111 and enters the inside of the cylindrical lock groove 113. In this way, the self-locking effect of the outer semi-enclosed gate valve body 4 and the inner fully-enclosed gate valve body 5 can be released. The anti-leakage valve of the offshore oil production well provides hydraulic oil to the inside of the shut-in oil chamber 906 through the hydraulic control system 8 so that the outer sleeve semi-enclosed gate valve body 4 is tightly held on the outside of the pipe column 3 and the inner embedded fully-enclosed gate valve body 5 is pressed on the outside of the pipe column 3, the rectangular locking block 101 can enter the inside of the rectangular locking groove 12 and push against the blocking and resetting block 13 to achieve the self-locking effect of the outer sleeve semi-enclosed gate valve body 4, and the cylindrical locking block 111 can enter the inside of the cylindrical locking groove 113 and push against the rectangular locking block 101 to achieve the self-locking effect of the inner embedded fully-enclosed gate valve body 5 In order to realize the self-locking effect, the hydraulic control system 8 provides hydraulic oil to the oil inlet pipe 910 outside the well opening oil chamber 907 so that the outer sleeve semi-sealed gate valve body 4 and the inner embedded fully sealed gate valve body 5 are reset, and the rectangular locking block 101 and the cylindrical locking block 111 can enter the rectangular locking groove 12 and the cylindrical locking groove 113 to release the self-locking effect of the outer sleeve semi-sealed gate valve body 4 and the inner embedded fully sealed gate valve body 5, that is, the anti-leakage valve of the marine oil well can quickly lock the outer sleeve semi-sealed gate valve body 4 and the inner embedded fully sealed gate valve body 5.

[0024] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An anti-leakage valve for an offshore oil production well, comprising a valve seat body (2) mounted on the top of a wellhead (1), and an outer sleeve semi-enclosed gate valve body (4) and an inner sleeve fully-enclosed gate valve body (5) symmetrically arranged outside a pipe string (3), characterized in that: The valve seat body (2) is provided with a receiving groove (6) in the middle, the outer sleeve semi-enclosed gate valve body (4) is slidably connected to the inside of the receiving groove (6), the outer sleeve semi-enclosed gate valve body (4) is provided with a sealing slide groove (7) in the middle, the embedded fully enclosed gate valve body (5) is slidably connected to the inside of the sealing slide groove (7), and the outside of the valve seat body (2) is symmetrically provided with a hydraulic connection mechanism (9) connected to a hydraulic control system (8), the hydraulic connection mechanism (9) comprising a hydraulic cylinder body (901) fixedly connected to the outside of the valve seat body (2), an inner movable body (902) fixedly connected to the outside of the outer sleeve semi-enclosed gate valve body (4), and a hydraulic control system (8) connected to the inner movable body (903). A plug rod (902) and an outer piston cylinder (903) fixedly connected to the outer side of the embedded fully enclosed gate valve body (5); the end of the inner piston rod (902) away from the outer semi-enclosed gate valve body (4) is fixedly connected to an inner piston block (904) located inside the outer piston cylinder (903); the end of the outer piston cylinder (903) away from the embedded fully enclosed gate valve body (5) is fixedly connected to an outer piston sleeve (905) located inside the hydraulic oil cylinder body (901); the outer piston sleeve (905) divides the inner cavity space of the hydraulic oil cylinder body (901) into a well-closing oil chamber (906) and a well-opening oil chamber (907); A self-locking member A (10) and a self-locking member B (11) for self-locking are respectively arranged at the top of the outer shell semi-enclosed gate valve body (4) and the inner embedded fully-enclosed gate valve body (5); a rectangular locking groove (12) is symmetrically fixedly connected to the top of the accommodating slot (6); a blocking and resetting block (13) is arranged inside the rectangular locking groove (12); the self-locking member A (10) and the self-locking member B (11) respectively comprise a rectangular locking block (101) and a cylindrical locking block (111) which can be reset by the blocking and resetting block (13).

2. The anti-leakage valve for an offshore oil well according to claim 1, characterized in that: The inner sides of the outer sleeve semi-enclosed gate valve body (4) and the inner side of the fully-enclosed gate valve body (5) are both provided with sealing rubber layers (14), and the upper and lower sides of the outer sleeve semi-enclosed gate valve body (4) are both provided with sealing rubber rings (15).

3. The anti-leakage valve for an offshore oil well according to claim 1, characterized in that: The inner piston rod (902) is located outside the outer piston cylinder (903), and an opening (908) that passes through the outer semi-enclosed gate valve body (4) is symmetrically provided on the outer side of one end of the outer piston cylinder (903) close to the embedded fully enclosed gate valve body (5). A sealing shaft ring (909) embedded in the valve seat body (2) is provided on the outside of the outer piston cylinder (903).

4. The anti-leakage valve for an offshore oil well according to claim 1, characterized in that: An oil inlet pipeline (910) and an oil return pipeline (911) which are in communication with the well-closing oil chamber (906) and the well-opening oil chamber (907) are symmetrically arranged on the outside of the hydraulic oil cylinder body (901), and a one-way valve (912) and an on-off valve (913) are respectively installed on the outside of the oil inlet pipeline (910) and the oil return pipeline (911).

5. The anti-leakage valve for an offshore oil well according to claim 4, characterized in that: The oil inlet pipeline (910) outside the well opening oil chamber (907) is composed of a pipeline A (9101) extending horizontally to the inside of the valve seat body (2) and a pipeline B (9102) extending vertically to the outside of the valve seat body (2), and the pipeline A (9101) and the pipeline B (9102) are respectively connected to the top and the side of the rectangular lock groove (12).

6. The anti-leakage valve for an offshore oil well according to claim 5, characterized in that: The interior of the pipeline B (9102) is fixedly connected to a limiting frame (16), the interior of the limiting frame (16) is slidably connected to a connecting rod (17) fixedly connected to the blocking and resetting block (13), and the top of the connecting rod (17) is fixedly connected to a limiting plate (18).

7. The anti-leakage valve for an offshore oil well according to claim 1, characterized in that: The self-locking member A (10) further comprises a rectangular slide groove (102) provided on the top of the outer sleeve semi-enclosed gate valve body (4), the rectangular locking block (101) being slidably connected inside the rectangular slide groove (102), and a locking spring A (103) being fixedly connected between the rectangular locking block (101) and the rectangular slide groove (102).

8. The anti-leakage valve for an offshore oil well according to claim 7, characterized in that: The self-locking member B (11) further comprises a cylindrical slide groove (112) provided at the top of the embedded fully enclosed gate valve body (5) and a cylindrical lock groove (113) connected to the rectangular slide groove (102); the cylindrical lock block (111) is slidably connected inside the cylindrical lock groove (113); and a locking spring B (114) is fixedly connected between the cylindrical lock block (111) and the cylindrical lock groove (113).

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