Complete set of pressure valve replacing device for old wellhead hidden danger treatment and construction method

Abstract

The invention discloses a complete set of pressure valve replacing device for old wellhead hidden danger treatment and a construction method, and relates to the technical field of oil and gas exploitation equipment maintenance and replacement, and the complete set of pressure valve replacing device comprises a blanking plug assembly, an outer side locking device and an inner side locking device. The outer side locking device applies external pressure to the whole blanking plug assembly in the processes of feeding of the blanking plug assembly, dismantling of an old valve and installation of a new valve, and the blanking plug assembly is prevented from being pushed out by high-pressure impact in a well. In the process that an old valve is taken down and a new valve is installed, the inner side locking device locks and fixes the blanking plug assembly at the position of an inner hole of a wellhead flange seat, mechanical anchoring is formed, and the situation that under the condition that the blanking plug assembly lacks external pressure, high-pressure fluid in a well rushes out the blanking plug is effectively prevented. Therefore, the under-pressure valve replacement operation is realized, and the safety and the construction efficiency of the under-pressure valve replacement operation are greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas production equipment maintenance and replacement, and in particular to a complete set of valve replacement device under pressure for old wellhead hidden danger treatment and a construction method. BACKGROUND

[0002] In the field of oil and natural gas production, a large number of early production oil and gas wells (commonly known as "old wells") have problems such as aging of wellhead devices and failure and leakage of key valves (such as master control valves and wing valves). When such old wellhead devices are designed, a standard internal thread or a hanging step for installing conventional tools for pressure operation (such as a plug) is often not reserved.

[0003] When the master control valve or the wing valve of such an old wellhead leaks and needs to be replaced, the existing technical solutions have significant limitations and safety risks. There are mainly two conventional treatment methods: One is to use the traditional well killing operation, that is, to balance the formation pressure by injecting well killing fluid into the wellbore, so as to replace the valve under no pressure; however, this method is high in cost, long in operation period, and the well killing fluid may cause irreversible damage to the production layer, affecting the subsequent productivity of the oil and gas well.

[0004] The second is to try to use conventional tools for pressure operation, but due to the lack of reliable anchoring points in the old wellhead, the tools cannot be effectively set and fixed. In the process of disassembling the old valve, the continuous high-pressure fluid in the well is easy to flush out the plug which is only set by hydraulic pressure, which has great safety hazards and may cause serious blowout accidents. Therefore, developing a valve replacement technology and device under pressure which can adapt to the special structure of the old wellhead and has high safety has become a technical problem to be solved in the field. SUMMARY

[0005] In view of the problems in the prior art, the present application provides a complete set of valve replacement device under pressure for old wellhead hidden danger treatment and a construction method.

[0006] In a first aspect, the present application provides a complete set of valve replacement device under pressure for old wellhead hidden danger treatment, which adopts the following technical solution: A complete set of valve replacement device under pressure for old wellhead hidden danger treatment, comprising: A plug assembly adapted to the inner hole of the wellhead flange seat for plugging the inner hole position of the wellhead flange seat; An external locking device comprising a transmission rod and a propulsion mechanism, the transmission rod being detachably connected with the plug assembly and being used to drive the plug assembly to pass through the valve body to be disassembled and move the plug assembly to the inner hole position of the wellhead flange seat; the propulsion mechanism provides propulsion power for the movement of the transmission rod; The inner locking device is arranged on the plugger assembly and is used for locking and fixing the plugger assembly in the inner hole of the wellhead flange seat.

[0007] Optionally, the complete set of the valve replacement device comprises a vertical valve replacement tool and a lateral valve replacement tool, the vertical valve replacement tool is used for replacing the valve body on the top of the wellhead flange seat, and the lateral valve replacement tool is used for replacing the valve body on the two sides of the wellhead flange seat.

[0008] Optionally, the pushing mechanism comprises a pushing cylinder and a pressing plate, the piston rod of the pushing cylinder is fixedly connected with the pressing plate, and the transmission rod is fixedly arranged on the pressing plate. The pushing cylinder of the vertical valve replacement tool is vertically arranged and is directly fixed on the wellhead flange seat through bolts. The pushing cylinder of the lateral valve replacement tool is horizontally arranged, and the end of the pushing cylinder is fixedly provided with a pull screw, a bridge frame is slidably arranged on the pull screw, and a nut is connected to the pull screw, and the bridge frame is fixed on the valve body on the side opposite to the valve body to be replaced through bolts.

[0009] Optionally, the control valve is further arranged, the control valve is fixed on the flange connection surface on the side, away from the wellhead flange seat, of the valve body to be replaced through a flange and bolts, the blowout preventer is further slidably arranged on the transmission rod, the blowout preventer is matched with the transmission rod, and the blowout preventer is fixed on the flange connection surface on the side, away from the valve body to be removed, of the control valve through bolts.

[0010] Optionally, the plugger assembly comprises a column body and a plug rubber sleeve arranged on the column body, an annular groove is arranged in the side wall of the column body, and the column body is arranged in the annular groove.

[0011] Optionally, a threaded sleeve is coaxially arranged on the bottom of the transmission rod, and a connecting screw is coaxially fixed on the top end of the column body, and the connecting screw is matched with the threaded sleeve.

[0012] Optionally, the inner locking device comprises a positioning pipe, a limiting block and a transmission mechanism, a containing groove is arranged in the bottom end of the column body along the length direction of the column body, the positioning pipe is slidably arranged in the containing groove along the length direction of the column body, a first elastic member is arranged in the containing groove and is used for driving the positioning pipe to slide away from the column body, a plurality of limiting blocks are arranged, each limiting block is rotatably arranged on the positioning pipe and is distributed along the circumferential direction of the positioning pipe, a second elastic member is arranged on the positioning pipe and is used for driving each limiting block to deflect towards the positioning pipe, and the transmission mechanism is used for driving each limiting block to deflect away from the positioning pipe at the same time and driving the positioning pipe to slide towards the central pipe column.

[0013] Optionally, the transmission mechanism comprises a sliding rod slidingly arranged in the column, a transmission block fixedly arranged on the sliding rod, and a limiting piece for preventing the sliding rod from sliding, the bottom end of the column is provided with a central hole, the sliding rod is arranged in the central hole and the positioning tube, the transmission block is provided with a guide slope for guiding the limiting pieces to deflect in the direction away from the positioning tube, and the transmission block is used for abutting against the end of the positioning tube and driving the positioning tube to slide in the direction close to the central column.

[0014] Optionally, the limiting piece comprises a limiting screw, the top end of the column is provided with a through hole in the length direction of the column, the limiting screw is rotatably arranged in the through hole, the side wall of the central hole is provided with a sliding groove in the length direction of the sliding rod, the side wall of the sliding rod is fixedly provided with a connecting block, the connecting block is slidingly arranged in the sliding groove, the through hole and the sliding groove are communicated, and the limiting screw is arranged in the sliding groove and threadedly matched with the connecting block.

[0015] In a second aspect, the application provides a construction method of a complete set of valve replacement device under pressure for old well mouth hidden danger treatment. The construction method of the complete set of valve replacement device under pressure for old well mouth hidden danger treatment comprises the following steps. S1, according to the position of the valve to be replaced, the complete set of valve replacement device under pressure is rigidly fixed to the well mouth position by external connection; S2, the plug assembly is installed at the end of the transmission rod, the valve body to be replaced is opened, the transmission rod is provided with a propelling power by the propelling mechanism, the plug assembly is driven to pass through the valve body to be removed and moves to the inner hole position of the flange seat, and the inner hole of the flange seat is sealed; S3, the propelling mechanism keeps the propelling force on the transmission rod, and the old valve is removed; S4, after the old valve is removed, the old valve is slid a certain distance along the length direction of the transmission rod, the plug assembly is locked and fixed at the inner hole position of the well mouth flange seat by the inner locking device on the plug assembly; S5, the propelling mechanism cancels the propelling force on the transmission rod, and the transmission rod is separated from the plug assembly, so that the old valve can be taken off from the transmission rod; S6, the new valve in the fully open state is installed and sleeved on the transmission rod; S7, the transmission rod is reconnected with the plug assembly, the propelling mechanism applies the propelling force to the transmission rod again, the plug assembly is tightly pressed against the inner hole position of the well mouth flange seat, and the locking of the plug assembly by the inner locking device is cancelled; S8, the new valve is installed and fixed on the well mouth flange seat, then the plug assembly is recovered, the plug assembly is taken out of the new valve, and the new valve is closed, so that the valve replacement operation is completed.

[0016] In summary, the present application includes at least one of the following beneficial technical effects: 1. The present application sets up the plugger assembly, the outer locking device and the inner locking device. The outer locking device applies external pressure to the entire plugger assembly during the plugger assembly sending, old valve removal and new valve installation process, preventing the plugger assembly from being pushed out by the high pressure in the well. The inner locking device locks and fixes the plugger assembly in the inner hole position of the wellhead flange seat during the removal of the old valve and the installation of the new valve, forming a mechanical anchor, effectively preventing the plugger from being pushed out by the high pressure fluid in the well in the absence of external pressure, thereby realizing the valve replacement operation under pressure and greatly improving the safety and construction efficiency of the valve replacement operation under pressure.

[0017] 2. The present application sets up the vertical valve replacement machine and the lateral valve replacement machine, which realizes the overall coverage of the top and both sides of the wellhead flange seat. The vertical valve replacement machine is specially used for replacing the top master control valve, and the lateral valve replacement machine is specially used for replacing the side wing valve. The two machines are used in cooperation to meet the replacement needs of valves at different positions of the old wellhead.

[0018] 3. The present application sets up the control valve and the blowout preventer. The control valve controls the pressure in the well to implement the next step under the premise of safety, and the blowout preventer can effectively control the fluid in the well during the plugger assembly advancing to the inner hole position of the wellhead flange seat, preventing blowout accidents and further enhancing the safety of the operation. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a structural schematic diagram of the vertical valve replacement machine used for expressing the embodiment of the present application; Figure 2 is a structural schematic diagram of the plugger assembly used for expressing the embodiment of the present application; Figure 3 is a structural schematic diagram of the lateral valve replacement machine used for expressing the embodiment of the present application.

[0020] Explanation of reference signs: 100, vertical valve replacement machine; 200, lateral valve replacement machine; 1, plugger assembly; 11, column body; 12, plug rubber; 13, connecting screw; 2, outer locking device; 21, conveying rod; 22, sending cylinder; 23, pressing plate; 24, threaded sleeve; 25, opposite-pull screw; 26, bridging frame; 3, inner locking device; 31, positioning tube; 32, limiting block; 33, first elastic member; 34, second elastic member; 35, sliding rod; 36, transmission block; 37, limiting screw; 38, connecting block; 4, control valve; 5, blowout preventer. DETAILED DESCRIPTION

[0021] The following will be combined with the accompanying drawings to further illustrate the present application. Figure 1 - the accompanying drawings Figure 3The technical solutions in the embodiments of the present application are clearly and completely described, and the described embodiments are only possible technical implementations of the present application, and not all possible implementations. Those skilled in the art can obtain other embodiments by combining the embodiments of the present application without creative labor, and these embodiments are also within the protection scope of the present application.

[0022] The present application sets the plugger assembly, the outer locking device and the inner locking device, realizes the valve replacement operation under pressure, and greatly improves the safety and construction efficiency of the valve replacement operation under pressure. And the complete valve replacement device under pressure can be divided into vertical valve replacement machine and lateral valve replacement machine, which are respectively used for replacing the valve body at the top and both sides of the wellhead flange seat. Through the cooperation of the vertical valve replacement machine and the lateral valve replacement machine, the replacement demand of the valve at different positions of the old wellhead can be met, and the top and both sides of the wellhead flange seat are fully covered, and the replacement demand of the valve at different positions of the old wellhead is met. The present application is further described in detail as follows: Embodiment 1 The present application discloses a complete valve replacement device under pressure for old wellhead hidden danger treatment. Referring to Figure 1 , the complete valve replacement device under pressure specifically adopts a vertical valve replacement machine 100, which comprises a plugger assembly 1, an outer locking device 2 and an inner locking device 3. The outer locking device 2 comprises a conveying rod 21 and a pushing mechanism. The conveying rod 21 is detachably connected with the plugger assembly 1, and the pushing mechanism provides power for the movement of the conveying rod 21 to drive the plugger assembly 1 to the inner hole position of the wellhead flange seat. The inner locking device 3 is arranged on the plugger assembly 1 and locks and fixes the plugger assembly 1 at the inner hole position of the wellhead flange seat, so as to achieve the effect of safely replacing the valve of the old wellhead under pressure. This is because the outer locking device 2 can apply external pressure to the plugger assembly 1 during the process of sending the plugger assembly 1, removing the old valve and installing the new valve, so as to prevent the plugger assembly 1 from being pushed out by the high pressure in the well. The inner locking device 3 forms a mechanical anchoring when the old valve is removed and the new valve is installed, so as to effectively prevent the plugger assembly 1 from being pushed out by the high pressure fluid in the well when lacking external pressure.

[0023] Referring to Figure 1 , the conveying rod 21 is usually a metal rod body with certain strength and rigidity to withstand the pressure in the pushing process. The pushing mechanism comprises a feeding cylinder 22 and a pressing plate 23. The feeding cylinder 22 is provided with a plurality of feeding cylinders 22, and each feeding cylinder 22 is vertically arranged. Each feeding cylinder 22 is directly fixed on the wellhead flange seat by bolts. The piston rod of each feeding cylinder 22 is fixedly connected with the pressing plate 23. The conveying rod 21 is fixedly arranged on the pressing plate 23, and the conveying rod 21 is vertically arranged. When the piston rod of the feeding cylinder 22 is extended or retracted, the pressing plate 23 and the conveying rod 21 will move together.

[0024] Referring to Figure 2Specifically, the plugging assembly 1 comprises a column body 11 and a plugging rubber sleeve 12 sleeved on the column body 11. The column body 11 is usually made of high-strength metal material and has a cylindrical shape to fit the inner hole of the wellhead flange seat. An annular groove is formed in the side wall of the column body 11, and the plugging rubber sleeve 12 is arranged in the annular groove. The plugging rubber sleeve 12 is generally made of elastic material such as rubber and has good sealing performance and pressure resistance. When the fluid pressure in the well acts on the plugging rubber sleeve 12, the plugging rubber sleeve 12 can expand and deform to achieve a tight seal with the inner hole of the wellhead flange seat. The plugging rubber sleeve 12 herein can also be replaced by other materials with similar elasticity and sealing performance, such as silica gel. The combination of the column body 11 and the plugging rubber sleeve 12 allows the plugging rubber sleeve 12 to expand uniformly under the pressure in the well, thereby improving the reliability and service life of the seal.

[0025] With reference to Figure 2 The bottom of the transfer rod 21 is coaxially provided with a threaded sleeve 24, which can be connected with the transfer rod 21 by bearings or the like to realize relative rotation. The top end of the column body 11 is coaxially fixedly provided with a connecting screw 13, and the connecting screw 13 is adapted to the threaded sleeve 24. By rotating the threaded sleeve 24, the transfer rod 21 and the plugging assembly 1 can be quickly connected and separated. This threaded connection method is simple in structure, reliable in connection, and convenient for quick installation and disassembly in a pressurized environment, thereby improving the operation efficiency and reducing the operation difficulty.

[0026] With reference to Figure 2 Specifically, the inner locking device 3 comprises a positioning pipe 31, a limiting block 32 and a transmission mechanism. The end of the column body 11 away from the connecting screw 13 is provided with a receiving groove along the length direction of the column body 11, the receiving groove is adapted to the positioning pipe 31, and the positioning pipe 31 is slidingly arranged in the receiving groove along the length direction of the column body 11. A first elastic member 33 for driving the positioning pipe 31 to slide away from the column body 11 is arranged in the receiving groove, and the first elastic member 33 can be a spring. When the positioning pipe 31 is not subjected to other external force, the first elastic member 33 pushes the positioning pipe 31 to slide away from the column body 11. The limiting block 32 is provided with a plurality of limiting blocks 32, each of which is rotationally arranged on the positioning pipe 31 and distributed along the circumferential direction of the positioning pipe 31. The positioning pipe 31 is respectively provided with a second elastic member 34 for driving each limiting block 32 to deflect towards the positioning pipe 31, and the second elastic member 34 can be a torsion spring sleeved on the rotating shaft of the limiting block 32.

[0027] With reference to Figure 2The transmission mechanism is used to drive each limiting block 32 to deflect simultaneously in a direction away from the positioning tube 31, and to drive the positioning tube 31 to slide towards the central column. Specifically, the transmission mechanism includes a sliding rod 35 that slides through the column 11, a transmission block 36 fixedly mounted on the sliding rod 35, and a limiting member to prevent the sliding rod 35 from sliding. A central hole is provided at the bottom end of the column 11, and the sliding rod 35 passes through the central hole and the positioning tube 31. The transmission block 36 is provided with a guide slope. When the sliding rod 35 drives the transmission block 36 to move closer to the column 11, the guide slope of the transmission block 36 will first contact the limit block 32, guiding each limit block 32 to deflect simultaneously away from the positioning tube 31, so that each limit block 32 opens. After the transmission block 36 moves a certain distance, the transmission block 36 abuts against the end of the positioning tube 31. Continuing to move the transmission block 36 can drive the positioning tube 31 to slide closer to the central tube, thereby locking each limit block 32 on the step of the flange seat inner hole, forming a mechanical anchor, and applying an anchoring force to the column 11 to slide closer to the wellhead flange seat, ensuring that the plug assembly 1 is firmly fixed in the inner hole of the wellhead flange seat.

[0028] Reference Figure 2 The limiting component includes a limiting screw 37. A through hole is formed at the top of the column 11 along its length, and the limiting screw 37 rotatably passes through the through hole. A groove is formed on the side wall of the central hole along the length of the sliding rod 35. A connecting block 38 is fixedly mounted on the side wall of the sliding rod 35 and slidably disposed within the groove. The through hole communicates with the groove, and the limiting screw 37 passes through the groove and is threadedly engaged with the connecting block 38. By rotating the limiting screw 37, the position of the sliding rod 35 can be precisely controlled, thereby driving the limiting block 32 and moving the positioning tube 31, ensuring reliable locking of the inner locking device 3.

[0029] Reference Figure 1 Specifically, the complete set of pressurized valve replacement equipment also includes a control valve 4. The control valve 4 is usually a valve with good sealing performance and control function. It is fixed to the flange connection surface of the valve body to be replaced on the side away from the wellhead flange seat by flange and bolts. The control valve 4 is specifically a pressure regulating valve, used to control the pressure in the well, and to continue to implement subsequent steps under the premise of ensuring safety.

[0030] Reference Figure 1A blowout preventer 5 is also slidably fitted onto the conveyor rod 21, and is bolted to the flange connection surface of the control valve 4 on the side away from the valve body to be disassembled. The blowout preventer 5 is generally a metal pipe adapted to the conveyor rod 21. After the control valve 4 controls the well pressure within the required range for construction, the control valve 4 is opened, and the plug assembly 1 and the conveyor rod 21 are inserted into the control valve 4. The blowout preventer 5 is then bolted to the flange connection surface of the control valve 4 on the side away from the valve body to be disassembled. As the plug assembly 1 is advanced to the inner hole position of the wellhead flange seat, it effectively controls the fluid in the well, prevents blowout accidents, and further enhances operational safety.

[0031] The implementation principle of a complete set of live valve replacement device for addressing hidden dangers at old wellheads, as described in this application embodiment, is as follows: This complete set of live valve replacement device solves the problem of live valve replacement at old wellheads through the coordinated work of the plug assembly 1, the outer locking device 2, and the inner locking device 3. Under pressure, the outer locking device 2 accurately delivers the plug assembly 1 to the inner hole of the wellhead flange seat and applies external pressure. The inner locking device 3 mechanically locks the plug assembly 1 at an appropriate time, preventing the impact of high-pressure fluid in the well on the plug assembly 1, improving the safety and efficiency of the valve replacement operation. Compared with traditional well control operations and conventional live operation tools, it has significant advantages, reducing damage to the producing formation and lowering operating costs and cycle time.

[0032] Example 2 Reference Figure 3 The difference from Embodiment 1 is that the complete set of pressurized valve replacement device specifically adopts a side valve replacement tool 200, mainly used to replace the valve bodies on both sides of the wellhead flange seat. Its propulsion mechanism has multiple horizontally positioned feed cylinders 22, and the transmission rod 21 is also horizontally positioned and parallel to the feed direction of the feed cylinders 22. Each feed cylinder 22 has a fixedly connected pull screw 25 at its end, and a bridging frame 26 is slidably fitted on each pull screw 25. Each pull screw 25 is threaded with a nut, and the bridging frame 26 is bolted to the valve body located on the opposite side of the valve body to be replaced. By adjusting the position of the nut, the position of the bridging frame 26 can be adjusted, thereby achieving horizontal fixation of the feed cylinders 22, adapting to the replacement requirements of the side valve body, and providing stable lateral support for the side valve replacement tool 200, ensuring stable valve replacement operation. By using the vertical valve replacement tool 100 and the lateral valve replacement tool 200 together, the replacement needs of valves in different positions of old wellheads can be met, achieving full coverage of the top and sides of the valve body of the wellhead flange seat, thus satisfying the replacement needs of valves in different positions of old wellheads.

[0033] Example 3 This application also discloses a construction method for a complete set of pressurized valve replacement devices for the treatment of hidden dangers at old wellheads, including the following steps: S1. Based on the location of the valve to be replaced, rigidly fix the complete pressurized valve replacement device to the wellhead location via external connection. If replacing the valve on top of the wellhead flange seat, use the vertical valve replacement tool 100 to directly fix the feed cylinder 22 to the wellhead flange seat with bolts; if replacing the valves on both sides of the wellhead flange seat, use the lateral valve replacement tool 200 to fix the bridging frame 26 to the valve body located on the opposite side of the valve body to be replaced with bolts, and adjust the nuts on the tie rods 25 to fix the feed cylinder 22 horizontally. During this process, wrenches and other tools are needed to tighten the bolts to ensure the device is securely fixed.

[0034] S2. Install the plugging assembly 1 at the end of the conveyor rod 21. By rotating the threaded sleeve 24, the connecting screw 13 engages with the threaded sleeve 24, thus connecting the conveyor rod 21 to the plugging assembly 1. Open the valve body to be replaced, start the propulsion mechanism, and extend the piston rod of the feed cylinder 22, driving the pressure plate 23 and the conveyor rod 21 to move. This causes the plugging assembly 1 to pass through the valve body to be disassembled and move to the inner hole position of the wellhead flange seat, sealing the inner hole of the flange seat. During this process, it is important to control the propulsion speed of the feed cylinder 22 to avoid damage to the device due to excessive speed.

[0035] S3. The propulsion mechanism maintains the propulsion force on the transmission rod 21, and the old valve is disassembled using appropriate tools, such as using a wrench to remove the connecting bolts. During the disassembly process, the outer locking device 2 continuously applies pressure to the plug assembly 1 to prevent it from being pushed out by the high pressure inside the well.

[0036] S4. After the old valve is disassembled, slide the old valve a certain distance along the length of the transmission rod 21. By rotating the limiting screw 37, the sliding rod 35 moves, which drives the transmission block 36 to push the limiting block 32 to deflect away from the positioning tube 31 and drive the positioning tube 31 to slide closer to the central tube column. This causes the limiting block 32 to be locked on the step of the wellhead flange seat, locking the plug assembly 1 in the position of the wellhead flange seat.

[0037] S5. The propulsion mechanism cancels the propulsion force on the transmission rod 21, rotates the threaded sleeve 24 to separate the transmission rod 21 from the blocker assembly 1, and the old valve can be removed from the transmission rod 21.

[0038] S6. Install the new valve, which is in the fully open position, onto the transmission rod 21 to ensure smooth operation between the new valve and the transmission rod 21.

[0039] S7. Reconnect the transmission rod 21 to the plugger assembly 1, restart the propulsion mechanism, extend the piston rod of the hydraulic cylinder 22, and press the plugger assembly 1 against the inner hole of the wellhead flange seat. Then rotate the limit screw 37 in the opposite direction to release the inner locking device 3 from locking the plugger assembly 1.

[0040] S8. Install and fix the new valve on the wellhead flange seat, and tighten the connecting bolts using a wrench or other tools. Then, retrieve the plugger assembly 1, and use the propulsion mechanism to remove the transmission rod 21 and the plugger assembly 1 from the new valve. Close the new valve to complete the valve replacement operation.

[0041] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A complete valve replacement device for wellhead hazard management under pressure, characterized in that, The utility model relates to a set of pressure valve changing device, including: Plugger assembly (1) is matched with the inner hole of wellhead flange seat, is used for plugging the inner hole position of wellhead flange seat; Outside locking device (2) includes transmission rod (21) and propelling mechanism, the transmission rod (21) is detachably connected with plugger assembly (1), and is used for driving plugger assembly (1) to pass through the valve body to be removed, and moves plugger assembly (1) to the inner hole position of wellhead flange seat;The propelling mechanism provides propelling power for the movement of transmission rod (21); Inside locking device (3) is arranged on plugger assembly (1) and is used for locking plugger assembly (1) in the inner hole position of wellhead flange seat.

2. The complete valve replacement device under pressure for well mouth hidden danger management according to claim 1, characterized in that: The set of pressure valve changing device includes vertical valve changing machine tool (100) and lateral valve changing machine tool (200), the vertical valve changing machine tool (100) is used for replacing the valve body on the top of wellhead flange seat, and the lateral valve changing machine tool (200) is used for replacing the valve body on both sides of wellhead flange seat.

3. The complete pressure-maintained valve-replacing device for old well mouth hidden danger treatment according to claim 2, characterized in that: The propelling mechanism includes feeding cylinder (22) and pressing plate (23), the piston rod of feeding cylinder (22) is fixedly connected with pressing plate (23), and transmission rod (21) is fixedly arranged on pressing plate (23); The feeding cylinder (22) of vertical valve changing machine tool (100) is vertically arranged and directly fixed on wellhead flange seat by bolt; The feeding cylinder (22) of lateral valve changing machine tool (200) is horizontally arranged, and the end of feeding cylinder (22) is fixedly provided with a pair of pull screws (25), a bridge frame (26) is slidably arranged on the pair of pull screws (25), and nuts are connected to the pair of pull screws (25), and the bridge frame (26) is fixed on the valve body on the opposite side of the valve body to be replaced by bolt.

4. The complete pressure-maintained valve-replacing device for old well mouth hidden danger treatment according to claim 1, characterized in that: It also includes control valve (4), which is fixed on the flange connection surface on the side of the valve body to be replaced away from wellhead flange seat by flange and bolt, and blowout preventer (5) is also slidably arranged on transmission rod (21), which is matched with transmission rod (21) and fixed on the flange connection surface on the side of control valve (4) away from the valve body to be removed by bolt.

5. The complete pressure-maintained valve-replacing device for old well mouth hidden danger treatment according to claim 1, characterized in that: The plugger assembly (1) includes a column body (11) and a plug rubber tube (12) sleeved on the column body (11), an annular groove is formed in the side wall of the column body (11), and the column body (11) is arranged in the annular groove.

6. The complete pressure-maintained valve-replacing device for old well mouth hidden danger treatment according to claim 5, characterized in that: The bottom of the transmission rod (21) is coaxially rotatably provided with a threaded sleeve (24), the top end of the column body (11) is coaxially fixedly provided with a connecting screw (13), and the connecting screw (13) is matched with the threaded sleeve (24).

7. The complete pressure-maintained valve-replacing device for old well mouth hidden danger treatment according to claim 5, characterized in that: The inner locking device (3) comprises a positioning tube (31), a limiting block (32) and a transmission mechanism, the bottom end of the column (11) is provided with a receiving groove along the length direction of the column (11), the positioning tube (31) is slidingly arranged in the receiving groove along the length direction of the column (11), the receiving groove is provided with a first elastic member (33) for driving the positioning tube (31) to slide away from the column (11), the limiting block (32) is provided with a plurality of limiting blocks (32), each limiting block (32) is rotatably arranged on the positioning tube (31) and is distributed along the circumference of the positioning tube (31), the positioning tube (31) is respectively provided with a second elastic member (34) for driving each limiting block (32) to deflect towards the positioning tube (31), and the transmission mechanism is used for driving each limiting block (32) to deflect away from the positioning tube (31) at the same time, and driving the positioning tube (31) to slide towards the central pipe column.

8. The complete pressure-maintained valve-replacing device for old well mouth hidden danger treatment according to claim 7, characterized in that: The transmission mechanism comprises a sliding rod (35) slidingly arranged in the column (11), a transmission block (36) fixedly arranged on the sliding rod (35), and a limiting member for preventing the sliding rod (35) from sliding, the bottom end of the column (11) is provided with a central hole, the sliding rod (35) is arranged in the central hole and the positioning tube (31), the transmission block (36) is provided with a guide slope, which is used for guiding each limiting block (32) to deflect away from the positioning tube (31) at the same time, and the transmission block (36) is used for abutting against the end of the positioning tube (31) and driving the positioning tube (31) to slide towards the central pipe column.

9. The complete pressure-maintained valve-replacing device for old well mouth hidden danger treatment according to claim 8, characterized in that: The limiting member comprises a limiting screw (37), the top end of the column (11) is provided with a through hole along the length direction of the column (11), the limiting screw (37) is rotatably arranged in the through hole, the side wall of the central hole is provided with a sliding groove along the length direction of the sliding rod (35), the side wall of the sliding rod (35) is fixedly provided with a connecting block (38), and the connecting block (38) is slidingly arranged in the sliding groove, the through hole is communicated with the sliding groove, the limiting screw (37) is arranged in the sliding groove and threadedly cooperates with the connecting block (38).

10. A construction method for the set of pressure-keeping valve-replacing devices for old wellhead hazard management according to any one of claims 1-9, characterized in that, The method comprises the following steps: S1, according to the position of the valve to be replaced, the complete set of pressure valve replacement device is rigidly fixed to the wellhead position through external connection; S2, the plug assembly (1) is installed at the end of the transmission rod (21), the valve body to be replaced is opened, the transmission rod (21) is provided with a propelling force by the propelling mechanism, the plug assembly (1) is driven to pass through the valve body to be removed, and moves to the inner hole position of the wellhead flange seat, and the inner hole of the flange seat is sealed; S3, the propelling mechanism keeps the propelling force of the transmission rod (21), and the old valve is disassembled; S4, after the old valve is disassembled, the old valve is slid along the length direction of the transmission rod (21) by a certain distance, and the plug assembly (1) is locked and fixed in the inner hole position of the wellhead flange seat by the inner locking device (3) on the plug assembly (1). S5, the pushing mechanism cancels the pushing force on the transmission rod (21) and separates the transmission rod (21) from the plug assembly (1), that is, the old valve is removed from the transmission rod (21); S6, the new valve in the fully open state is installed and sleeved on the transmission rod (21); S7, the transmission rod (21) is reconnected with the plug assembly (1), and the pushing mechanism again applies a pushing force to the transmission rod (21), so that the plug assembly (1) is pressed against the inner hole position of the wellhead flange seat, and the locking of the inner locking device (3) to the plug assembly (1) is cancelled; S8, the new valve is installed and fixed on the wellhead flange seat, and then the plug assembly (1) is recovered, the plug assembly (1) is taken out of the new valve, and the new valve is closed, completing the valve replacement operation.

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