A leak-proof wellhead gate valve for oil mining

Abstract

This invention provides a leak-proof wellhead gate valve for oil extraction, relating to the field of wellhead valve technology. The wellhead gate valve body includes a valve body, an adjusting mechanism, and a valve core assembly. Connecting pipes are welded to both ends of the valve body, and a support frame is welded to the top of the valve body. The adjusting mechanism includes an outer adjusting mechanism and an inner adjusting mechanism, with the inner adjusting mechanism passing through the interior of the outer adjusting mechanism. An integrally formed lifting cavity is formed on the top of the valve body. This invention utilizes the outer adjusting mechanism to press down the outer valve core assembly, which, in conjunction with the extension of the inner valve core assembly, locks the interior of the outer valve core assembly. This prevents excessive liquid pressure in the subsequent connecting pipe inflow section from lifting one side of the gate, thereby improving the stability after closure, achieving staged closure to reduce the impact of water hammer, and allowing liquid to be discharged from the valve body cavity, enabling timely detection of leaks.

Description

Technical Field

[0001] The invention relates to the technical field of wellhead valves, in particular to an anti-leakage wellhead gate valve used in petroleum exploitation. Background Art

[0002] ‌ Wellhead gate valves used in oil production can accurately control the flow and pressure at the wellhead to meet the needs of oil and gas well production. When an abnormal situation occurs at the wellhead, the gate valve can be closed in time to avoid safety accidents of oil and gas wells. Due to its good sealing performance and long service life, wellhead gate valves can extend the service life of equipment. In addition, wellhead gate valves have a simple structure, are easy to maintain, and are very easy to replace. Therefore, wellhead gate valves used in oil production are widely used in various drilling construction processes.

[0003] In the prior art, in order to improve the sealing effect of the pipeline connecting hole in the valve body after closing, the gate plates on both sides of the gate plate are set to an inclined state to ensure that the downward pressure can act in the docking area. However, this solution will also cause the upward thrust to be applied to the gate plate in the reverse direction when the liquid pressure in the inlet section is too high, and then after long-term use, there is a certain probability that the sealing of the bottom of the gate plate will decrease, and leakage problems will still occur after closing. On the other hand, a large amount of liquid will remain in the internal cavity of the conventional gate valve whether it is in the open state or the closed state, which is difficult to discharge, and the internal valve core part cannot be quickly detected from the outside after leakage. Summary of the invention

[0004] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a leakage-proof wellhead gate valve for oil development to solve the problems raised in the above-mentioned background technology. The present invention uses the outer layer adjustment mechanism to press down the outer layer valve core assembly, and then cooperates with the inner layer valve core assembly to push out, so as to lock the inside of the outer layer valve core assembly, thereby avoiding the gate plate on one side from being lifted up when the liquid pressure in the subsequent docking pipeline inflow section is too high, thereby achieving the effect of improving the stability after closure, enhancing the leakage prevention capability, and realizing staged closure, reducing the influence of the water hammer effect, and being able to discharge the liquid in the valve body cavity, so that leakage can be detected in time when it occurs.

[0005] In order to achieve the above-mentioned purpose, the present invention is realized by the following technical scheme: a kind of anti-leakage wellhead gate valve for oil development, comprising a wellhead gate valve body, the wellhead gate valve body comprising a valve body, an adjusting mechanism and a valve core assembly, butt-jointed pipes are welded at both ends of the valve body, a support frame is welded at the top of the valve body, the adjusting mechanism comprises an outer layer adjusting mechanism and an inner layer adjusting mechanism, the inner layer adjusting mechanism passes through the inside of the outer layer adjusting mechanism, a lifting cavity is integrally formed at the top of the valve body, the outer layer adjusting mechanism passes through the inside of the lifting cavity, threaded holes are provided at the top of the support frame and the top of the lifting cavity, the valve core assembly comprises an outer layer valve core assembly and an inner layer valve core assembly, the bottom of the outer layer adjusting mechanism is movably connected to the surface of the outer layer valve core assembly, both ends of the inner layer valve core assembly are embedded in the inside of the outer layer valve core assembly, and a positioning plate is integrally formed at the bottom of the outer layer valve core assembly, the positioning plate is embedded below the inner wall of the valve body, both sides of the outer layer valve core assembly are used to block the butt-jointed pipe, and a pressure gauge is installed on the surface of the valve body.

[0006] Furthermore, the outer valve core assembly includes a gate plate and a guide channel, the guide channel is integrally formed on the side of the gate plate, an outer guide hole is opened on the surface of the guide channel, a docking hole is opened in the middle of the gate plate, a linkage frame is welded on the top of the gate plate, a docking ring is integrally formed in the middle of the linkage frame, and a through hole is opened in the middle of the docking ring.

[0007] Furthermore, guide rods are inserted at both ends of the linkage frame, a guide channel is opened on the top of the valve body, the guide rod is embedded in the interior of the guide channel, the number of the gate plate and the guide channel are two, and the side of the gate plate is in a sloped state, and the gate plate is connected to the interior of the docking pipe through the docking hole.

[0008] Furthermore, a positioning hole is provided at the bottom end of the inner wall of the valve body, and the gate plate is embedded into the positioning hole through the positioning plate at the bottom, and one end of the docking pipe inside the valve body is tilted as a whole.

[0009] Furthermore, the outer layer adjustment mechanism includes a lifting sleeve and a threaded sleeve, the threaded sleeve is welded to the top of the lifting sleeve, and a first hand wheel is welded to the top of the threaded sleeve.

[0010] Furthermore, the bottom of the lifting sleeve is embedded in the interior of the docking ring, and the inner wall diameter of the lifting sleeve is the same as the diameter of the through hole. The threaded sleeve passes through the threaded hole at the top of the lifting cavity. The lifting sleeve cooperates with the docking ring to control the lifting movement of the outer valve core assembly.

[0011] Furthermore, the inner layer adjustment mechanism includes a lifting rod and a plug-in plate, a second hand wheel is welded to the top of the lifting rod, the bottom of the lifting rod is movably connected to the plug-in plate part through a sleeved docking bearing, and the surface of the lifting rod is provided with an external thread.

[0012] Furthermore, a limit plate is integrally formed at the bottom of the plug-in board, and the limit plate is embedded in the bottom of the inner wall of the valve body. The lifting rod passes through the inside of the threaded sleeve, and the surface of the lifting rod fits with the inner wall of the threaded sleeve. The lifting rod passes through the threaded hole on the support frame through the external threaded area on the surface.

[0013] Furthermore, the inner valve core assembly includes a first telescopic column, a second telescopic column and an inclined plate, the surfaces of the first telescopic column and the second telescopic column are both provided with inner guide holes, and the bottom of the second telescopic column is provided with an overflow hole, and one end of the first telescopic column and the second telescopic column is both provided with a center hole.

[0014] Furthermore, the first telescopic column and the second telescopic column are both embedded in the docking hole on the inner side of the gate plate, a return spring is connected between the two inclined plates, the plug-in plate is simultaneously pressed against the two inclined plates after being moved downward, the first telescopic column and the second telescopic column are embedded in the interior of the outer valve core assembly after being moved downward through the inner layer adjustment mechanism, and the end face diameters of the first telescopic column and the second telescopic column are the same as the inner wall diameter of the docking pipe.

[0015] Beneficial effects of the invention:

[0016] 1. The anti-leakage wellhead gate valve used in oil development uses the outer regulating mechanism to press down the outer valve core assembly, and then pushes out the inner valve core assembly to lock the inside of the outer valve core assembly, so as to avoid the gate on one side being lifted when the liquid pressure in the subsequent docking pipeline inflow section is too high, thereby achieving the effect of improving the stability after closure and enhancing the anti-leakage ability.

[0017] 2. When the leak-proof wellhead gate valve used in oil development closes the entire docking pipeline by sequentially closing the outer valve core assembly and the inner valve core assembly through two regulating machines, a staged closure will be achieved to avoid severe water hammer effect after rapid closure, reduce the impact of the water hammer effect, and thus improve the protection effect of the entire gate valve and pipeline.

[0018] 3. When the inner valve core assembly is closed by the anti-leakage wellhead gate valve used in oil development, the first telescopic column can be sealed first. At this time, the cavity inside the valve body can still be connected with the docking pipe at the rear discharge end. During this period of time, the liquid in the valve body cavity can be discharged, and then the other second telescopic column can be completely sealed. At this time, the leakage can be detected in time with the help of an external pressure gauge. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic structural diagram of the appearance of an anti-leakage wellhead gate valve for oil mining according to the present invention;

[0020] Figure 2 This is an internal cross-sectional view of an anti-leakage wellhead gate valve for oil mining according to the present invention;

[0021] Figure 3 This is a diagram of the internal structure of the valve body of the present invention;

[0022] Figure 4 It is a connection diagram of the valve core assembly part of the present invention;

[0023] Figure 5 It is a structural schematic diagram of the inner valve core component part of the present invention;

[0024] Figure 6 It is a structural schematic diagram of the inner layer adjustment mechanism part of the present invention;

[0025] Figure 7 for Figure 2 A magnified image of area A;

[0026] In the figure: 1. valve body; 2. docking pipeline; 3. lifting cavity; 4. guide channel; 5. support frame; 6. threaded hole; 7. outer layer adjustment mechanism; 8. inner layer adjustment mechanism; 9. outer layer valve core assembly; 10. inner layer valve core assembly; 11. lifting sleeve; 12. threaded sleeve; 13. first hand wheel; 14. gate; 15. positioning plate; 16. docking hole; 17. guide rod; 18. linkage frame; 19. docking ring; 20. diversion channel; 21. outer layer diversion hole; 22. first telescopic column; 23. second telescopic column; 24. inclined plate; 25. reset spring; 26. center hole; 27. inner layer diversion hole; 28. overflow hole; 29. ​​lifting rod; 30. external thread; 31. second hand wheel; 32. docking bearing; 33. plug-in plate; 34. positioning hole; 35. through hole; 36. pressure gauge; 37. limit plate. DETAILED DESCRIPTION

[0027] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0028] See also Figures 1 to 7The present invention provides the following technical solutions: a leak-proof wellhead gate valve for oil development, comprising a wellhead gate valve body, the wellhead gate valve body comprising a valve body 1, an adjusting mechanism and a valve core assembly, butt-jointed pipes 2 are welded at both ends of the valve body 1, a support frame 5 is welded at the top of the valve body 1, the adjusting mechanism comprises an outer adjusting mechanism 7 and an inner adjusting mechanism 8, the inner adjusting mechanism 8 passes through the inside of the outer adjusting mechanism 7, a lifting cavity 3 is integrally formed on the top of the valve body 1, the outer adjusting mechanism 7 passes through the inside of the lifting cavity 3 The top of the support frame 5 and the top of the lifting cavity 3 are both provided with threaded holes 6, the valve core assembly includes an outer valve core assembly 9 and an inner valve core assembly 10, the bottom of the outer adjustment mechanism 7 is movably connected to the surface of the outer valve core assembly 9, both ends of the inner valve core assembly 10 are embedded in the inner part of the outer valve core assembly 9, and the bottom of the outer valve core assembly 9 is integrally formed with a positioning plate 15, the positioning plate 15 is embedded under the inner wall of the valve body 1, and the two sides of the outer valve core assembly 9 are used to block the docking pipeline 2. The anti-leakage wellhead gate valve used in oil mining is installed in the pipeline at the top of the wellhead to control the opening and closing of the pipeline.

[0029] When the present invention is used, the installation can be completed by connecting the flanges at both ends of the docking pipe 2 to the delivery pipe on the wellhead. When the liquid inside the pipe needs to be transported, the outer layer regulating mechanism 7 and the inner layer regulating mechanism 8 are controlled to move upward, so that the outer layer valve core assembly 9 and the inner layer valve core assembly 10 will not be pressed against the inner end of the docking pipe 2, and the liquid inside the external pipe can be directly passed through the gate valve to flow into the other end. When the pipeline needs to be closed, the outer layer regulating mechanism 7 is first controlled to move downward, so that the outer layer valve core assembly 9 The gate plates 14 at both ends are against one end of the interior of the docking pipe 2. At this time, the gate plates 14 can be used to initially block the liquid inside the docking pipe 2. However, in this state, a small amount of liquid can still pass through the inner valve core assembly 10 in the middle of the gate plates 14 to achieve a flow effect. Subsequently, the inner regulating mechanism 8 is controlled to move downward again until the inner valve core assembly 10 synchronously seals the interior of the outer valve core assembly 9, and at the same time achieves a locking effect on the outer valve core assembly 9, thereby completing a complete closure of the wellhead pipeline.

[0030] In this embodiment, the outer valve core assembly 9 includes a gate plate 14 and a guide channel 20, the guide channel 20 is integrally formed on the side of the gate plate 14, an outer guide hole 21 is opened on the surface of the guide channel 20, a docking hole 16 is opened in the middle of the gate plate 14, a linkage frame 18 is welded on the top of the gate plate 14, a docking ring 19 is integrally formed in the middle of the linkage frame 18, and a through hole 35 is opened in the middle of the docking ring 19. Guide rods 17 are inserted at both ends of the linkage frame 18, a guide channel 4 is opened on the top of the valve body 1, and the guide rod 17 is embedded in the inside of the guide channel 4. The number of the gate plate 14 and the guide channel 20 are both two, and the side of the gate plate 14 is in an inclined state. The gate plate 14 is connected to the inside of the docking pipe 2 through the docking hole 16. A positioning hole 34 is provided at the bottom end of the inner wall of the valve body 1, and the gate 14 is embedded in the positioning hole 34 through the positioning plate 15 at the bottom. The end of the docking pipe 2 inside the valve body 1 is tilted as a whole. After the outer valve core assembly 9 is pressed down by the outer adjustment mechanism 7, the inner valve core assembly 10 is pushed out to lock the inner part of the outer valve core assembly 9, thereby preventing the gate 14 on one side from being lifted up when the liquid pressure in the inflow section of the docking pipe 2 is too high, thereby achieving the effect of improving the stability after closure and enhancing the anti-leakage ability.

[0031] Specifically, when the outer valve core assembly 9 is controlled to move downward by the outer adjustment mechanism 7, the gate plate 14 will be moved downward and pressed against one end of the interior of the docking pipe 2, and will be embedded into the interior of the positioning hole 34 through the positioning plate 15 to achieve the purpose of pre-guiding and positioning. After the pressing and pressing are completed, the docking hole 16 will be completely aligned with the internal channel of the docking pipe 2. At this time, the inner valve core assembly 10 can be driven to move by controlling the inner adjustment mechanism 8, so that the inner valve core assembly 10 can be extended toward both ends until the ends of the first telescopic column 22 and the second telescopic column 23 are embedded into the interior of the outer valve core assembly 9. At this time, the increase in liquid pressure inside the pipeline can be avoided, which will cause the gate plate 14 to be lifted up in the subsequent long-term closed state, thereby ensuring that the docking hole 16 in the gate plate 14 can always be accurately aligned with the interior of the docking pipe 2.

[0032] In this embodiment, the outer adjustment mechanism 7 includes a lifting sleeve 11 and a threaded sleeve 12, the threaded sleeve 12 is welded to the top of the lifting sleeve 11, and a first hand wheel 13 is welded to the top of the threaded sleeve 12. The bottom of the lifting sleeve 11 is embedded in the inside of the docking ring 19, and the inner wall diameter of the lifting sleeve 11 is the same as the diameter of the through hole 35. The threaded sleeve 12 passes through the threaded hole 6 at the top of the lifting cavity 3, and the lifting sleeve 11 cooperates with the docking ring 19 to control the lifting movement of the outer valve core assembly 9.

[0033] Specifically, the threaded sleeve 12 can be driven to rotate by rotating the first hand wheel 13, and the lifting sleeve 11 at the bottom can be moved downward by cooperating with the threaded hole 6 at the top of the lifting cavity 3. Therefore, under the action of the docking ring 19 and the linkage frame 18, the entire outer valve core assembly 9 at the bottom is moved downward, so that the gate plates 14 at both ends of the valve core assembly are pressed downward on the inner end of the docking pipe 2. During the whole process, the inner valve core assembly 10 will also be driven to move downward synchronously, but in this stage, the inner valve core assembly 10 does not produce lateral telescopic movement.

[0034] In this embodiment, the inner adjustment mechanism 8 includes a lifting rod 29 and a plug-in plate 33. A second hand wheel 31 is welded to the top of the lifting rod 29. The bottom of the lifting rod 29 is movably connected to the plug-in plate 33 through a sleeved docking bearing 32. The surface of the lifting rod 29 is provided with an external thread 30. The bottom of the plug-in plate 33 is integrally formed with a limit plate 37, and the limit plate 37 is embedded in the bottom of the inner wall of the valve body 1. The lifting rod 29 passes through the inside of the threaded sleeve 12, and the surface of the lifting rod 29 fits the inner wall of the threaded sleeve 12. The lifting rod 29 passes through the threaded hole 6 on the support frame 5 through the external thread 30 area on the surface. When the outer valve core assembly 9 and the inner valve core assembly 10 are sequentially closed by two adjustment machines to close the entire docking pipeline 2, a staged closing will be achieved to avoid a serious water hammer effect after rapid closing, reduce the impact of the water hammer effect, and thus improve the protection effect of the entire gate valve and the pipeline part.

[0035] Specifically, after the outer valve core assembly 9 is moved downward through the above-mentioned operation process, the docking pipe 2 is blocked and pressed against by the gate plate 14, and the inflow end of the docking pipe 2 will be blocked, but a small amount of liquid will pass through the central hole 26 in the inner valve core assembly 10, and then pass through the inner guide hole 27 and the outer guide hole 21 inside the telescopic column in turn to enter the chamber inside the valve core again, and also flow through the outer guide hole 21 on the other end guide channel 20 and the inner guide hole 27 inside to flow into the docking pipe 2 on the other side, thereby avoiding rapid and complete closure. Subsequently, after the inner valve core assembly 10 is moved by controlling the inner adjustment mechanism 8, the outer guide hole 21 and the inner guide hole 27 can be staggered, so that the remaining liquid is also sealed, and with the help of this staged sealing process, the influence of the water hammer effect is reduced.

[0036] In this embodiment, the inner valve core assembly 10 includes a first telescopic column 22, a second telescopic column 23 and an inclined plate 24. The surfaces of the first telescopic column 22 and the second telescopic column 23 are provided with inner guide holes 27, and the bottom of the second telescopic column 23 is provided with an overflow hole 28. One end of the first telescopic column 22 and the second telescopic column 23 is provided with a center hole 26. The first telescopic column 22 and the second telescopic column 23 are both embedded in the docking hole 16 on the inner side of the gate plate 14. A return spring 25 is connected between the two inclined plates 24. The plug-in board 33 is moved downward and rests on the two inclined plates 24 at the same time. The first telescopic column 22 and the second telescopic column 23 are moved downward by the inner layer adjustment mechanism 8 and embedded in the outer valve core assembly 9. The end face diameters of the first telescopic column 22 and the second telescopic column 23 are the same as the inner wall diameter of the docking pipe 2. When closing the inner valve core assembly 10, the first telescopic column 22 can be partially blocked first. At this time, the cavity inside the valve body 1 can still be connected to the docking pipe 2 at the rear discharge end. During this period of time, the liquid in the cavity of the valve body 1 can be discharged, and then the other second telescopic column 23 is completely sealed. At this time, with the cooperation of the external pressure gauge 36, leakage can be detected in time.

[0037] Specifically, when the two telescopic columns are extended by controlling the inner adjustment mechanism 8, that is, by rotating the second hand wheel 31, the plug-in plate 33 at the bottom is embedded between the two inclined plates 24 by means of the external thread 30 and the threaded hole 6 on the support frame 5, so as to realize the support of the telescopic column. At this time, the inner guide hole 27 on the first telescopic column 22 will be staggered with the corresponding outer guide hole 21. At this time, the liquid at the inflow end cannot enter the cavity inside the valve body 1, but in this state, the overflow hole 28 on the second telescopic column 23 still connects the cavity inside the valve body 1 with the center hole 26 inside the second telescopic column 23, so that the liquid inside the valve body 1 can continue to overflow and discharge toward the other side. At this time, the inside of the cavity is no longer in a full state. Therefore, if the valve body 1 leaks later, resulting in the liquid inside the chamber being filled, it can be directly viewed through the external pressure gauge 36. The pressure gauge 36 is an existing mature technology and does not belong to the protection scope of the present invention. Therefore, its internal structure and principle are not described in detail here.

[0038] The basic principles and main features of the present invention and the advantages of the present invention are shown and described above. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention.

[0039] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A leak-proof wellhead gate valve for oil mining, comprising a wellhead gate valve body, characterized in that: The wellhead gate valve body comprises a valve body (1), an adjusting mechanism and a valve core assembly. The two ends of the valve body (1) are welded with docking pipes (2). The top of the valve body (1) is welded with a support frame (5). The adjusting mechanism comprises an outer adjusting mechanism (7) and an inner adjusting mechanism (8). The inner adjusting mechanism (8) passes through the inside of the outer adjusting mechanism (7). A lifting cavity (3) is integrally formed on the top of the valve body (1). The outer adjusting mechanism (7) passes through the inside of the lifting cavity (3). The top of the support frame (5) and the top of the lifting cavity (3) are both provided with threaded holes (6). The valve core assembly comprises an outer valve core assembly (9) and an inner valve core assembly (10). The bottom of the outer adjusting mechanism (7) is connected to the outer adjusting mechanism (7). The inner valve core assembly (9) is movably connected to the surface of the inner valve core assembly (9), both ends of the inner valve core assembly (10) are embedded in the interior of the outer valve core assembly (9), and the bottom of the outer valve core assembly (9) is integrally formed with a positioning plate (15), and the positioning plate (15) is embedded below the inner wall of the valve body (1), and the two sides of the outer valve core assembly (9) are used to block the docking pipeline (2), and a pressure gauge (36) is installed on the surface of the valve body (1), and the outer valve core assembly (9) includes a gate plate (14) and a guide channel (20), and the guide channel (20) is integrally formed on the side of the gate plate (14), and the surface of the guide channel (20) is provided with an outer guide hole (21), and the middle of the gate plate (14) is provided with a docking hole (16) ), a linkage frame (18) is welded to the top of the gate plate (14), a docking ring (19) is integrally formed in the middle of the linkage frame (18), a through hole (35) is opened in the middle of the docking ring (19), the outer adjustment mechanism (7) comprises a lifting sleeve (11) and a threaded sleeve (12), the threaded sleeve (12) is welded to the top of the lifting sleeve (11), a first hand wheel (13) is welded to the top of the threaded sleeve (12), the bottom of the lifting sleeve (11) is embedded in the interior of the docking ring (19), and the inner wall diameter of the lifting sleeve (11) is the same as the diameter of the through hole (35), the threaded sleeve (12) passes through the threaded hole (6) at the top of the lifting cavity (3), and the lifting sleeve (11) ) cooperates with the docking ring (19) to control the outer valve core assembly (9) to perform lifting movement, the inner adjustment mechanism (8) includes a lifting rod (29) and a plug-in plate (33), the top of the lifting rod (29) is welded with a second hand wheel (31), the bottom of the lifting rod (29) is partially rotatably connected to the plug-in plate (33) through a sleeved docking bearing (32), the surface of the lifting rod (29) is provided with an external thread (30), the inner valve core assembly (10) includes a first telescopic column (22), a second telescopic column (23) and an inclined plate (24), the surfaces of the first telescopic column (22) and the second telescopic column (23) are both provided with inner guide holes (27), and the bottom of the second telescopic column (23) is provided with an overflow hole (28),One end of each of the first telescopic column (22) and the second telescopic column (23) is provided with a central hole (26).

2. The anti-leakage wellhead gate valve for oil mining according to claim 1, characterized in that: Guide rods (17) are inserted at both ends of the linkage frame (18), a guide channel (4) is provided at the top of the valve body (1), and the guide rod (17) is embedded in the guide channel (4). The number of the gate plate (14) and the number of the guide channel (20) are both two, and the side edge of the gate plate (14) is in an inclined state. The gate plate (14) is connected to the inside of the docking pipe (2) through the docking hole (16).

3. The anti-leakage wellhead gate valve for oil mining according to claim 2, characterized in that: A positioning hole (34) is provided at the bottom end of the inner wall of the valve body (1), and the gate plate (14) is embedded into the interior of the positioning hole (34) through a positioning plate (15) at the bottom. One end of the docking pipe (2) located inside the valve body (1) is in an overall inclined state.

4. The anti-leakage wellhead gate valve for oil mining according to claim 3 is characterized by: The bottom of the plug plate (33) is integrally formed with a limit plate (37), and the limit plate (37) is embedded in the bottom of the inner wall of the valve body (1). The lifting rod (29) passes through the inside of the threaded sleeve (12), and the surface of the lifting rod (29) fits the inner wall of the threaded sleeve (12). The lifting rod (29) passes through the threaded hole (6) on the support frame (5) through the external thread (30) area on the surface.

5. The anti-leakage wellhead gate valve for oil mining according to claim 4, characterized in that: The first telescopic column (22) and the second telescopic column (23) are both embedded in the docking hole (16) on the inner side of the gate plate (14); a return spring (25) is connected between the two inclined plates (24); the plug-in plate (33) is moved downward and abuts against the two inclined plates (24) at the same time; the first telescopic column (22) and the second telescopic column (23) are moved downward by the inner layer adjustment mechanism (8) and embedded in the outer layer valve core assembly (9); and the end face diameters of the first telescopic column (22) and the second telescopic column (23) are the same as the inner wall diameter of the docking pipe (2).

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