Maintenance device, system and method for wellhead valve

Abstract

The invention belongs to the technical field of opening and closing operation of large valves of gas wells, and particularly relates to a maintenance device, system and method for a wellhead valve. The maintenance device comprises a hydraulic motor, a fixing mechanism, a maintenance cylinder, a connecting mechanism and a cleaning mechanism. One end of the maintenance cylinder is connected with the hydraulic motor, the other end of the maintenance cylinder is connected with the connecting mechanism, and the inner side wall of the upper end of the maintenance cylinder is connected with a cleaning mechanism; a fixing mechanism, a liquid inlet connector and a liquid outlet connector are connected to the side wall of the hydraulic motor. According to the invention, the technical manual maintenance efficiency is effectively improved, and the working intensity is reduced. The hydraulic pump and the hydraulic motor are adopted for providing power, compared with the prior art, the labor intensity of maintenance operation can be reduced by 90% or above, one operator can easily complete maintenance of a single valve within 10 minutes, and the operation efficiency is improved by 60% or above. The method can adapt to large-scale wellhead valve maintenance operation under the conditions of tight gas resource blocks and a large number of wells managed per capita.

Description

Technical Field

[0001] The invention belongs to the technical field of switch operation of large-scale gas well valves, and in particular relates to a maintenance device, system and method for wellhead valves. Background Art

[0002] As an important production equipment in the natural gas extraction process, the wellhead gas tree has the functions of daily process switching, pressure adjustment, maintenance and testing operations, and implementation of production measures. It is a wellhead device that connects the gas well oil, casing and ground supporting equipment, and plays a vital role in the natural gas production process. It is mainly composed of a main gate, a four-way gate, a tubing gate, a needle valve, a pressure gate, and a casing gate. In the actual production and operation process, the gas tree is in a complex and harsh field environment, which aggravates the oxidation and rusting speed of the exposed metal parts; in addition, the interaction between water and impurities in the high-pressure medium transported increases the probability of jamming and erosion of internal transmission parts, resulting in inflexible operation of the valve, increased switching torque, rust and jamming, and other frequent faults. Regular maintenance work such as cleaning, lubrication, and grease injection is required for the exposed screw and internal transmission parts.

[0003] Existing technical solution: According to the technical characteristics of gas tree valve maintenance, in the maintenance process, it is necessary to manually open and close the valve, remove the sludge on the screw rod, apply oil butter, manually inject grease through the grease injection port, and manually open and close the valve more than twice, relying on the up and down movement of the valve stem to remove the sludge in the valve sleeve gap and fully lubricate the transmission parts. The average time for maintaining a single valve is more than 30 minutes, with low operation efficiency and high labor intensity. Summary of the invention

[0004] The present invention provides a maintenance device, system and method for wellhead valves. One of its purposes is to provide a device that can solve the problem of time-consuming and labor-intensive manual operation in centralized valve maintenance operations; the second purpose is to provide a device with good portability; the third purpose is to provide an auxiliary device that can adapt to inter-well transportation and wellhead layout, and can achieve the goal that except for simple assembly and grease injection, no other operations are required, and a single person can easily and quickly complete the maintenance of a single valve.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A maintenance device for a wellhead valve comprises a hydraulic motor, a fixing mechanism, a maintenance cylinder, a connecting mechanism and a cleaning mechanism; one end of the maintenance cylinder is connected to the hydraulic motor, the other end of the maintenance cylinder is connected to the connecting mechanism, the cleaning mechanism is connected to the inner side wall of the upper end of the maintenance cylinder; the fixing mechanism, a liquid inlet joint and a liquid outlet joint are connected to the side wall of the hydraulic motor.

[0007] The fixing mechanism comprises a fixing handle, a fixing rod and a fixing ear plate; the fixing handle is connected to the hydraulic motor through a fixing piece, the fixing handle is connected to the fixing ear plate, and the fixing rod is plugged into the fixing handle.

[0008] The fixing member comprises a flat washer, an elastic washer and a bolt; the bolt connects the fixing ear plate with the fixing handle through a thread, and the flat washer and the elastic washer are arranged between the bolt and the fixing ear plate.

[0009] The fixing rod includes a vertical connecting rod, a long horizontal sleeve, a short horizontal sleeve and two diagonal support rods; the long horizontal sleeve and the short horizontal sleeve have different lengths; the long horizontal sleeve and the short horizontal sleeve are arranged in parallel, and the long horizontal sleeve and the short horizontal sleeve are respectively vertically connected to the upper and lower ends of the opposite sides of the vertical connecting rod; the two diagonal support rods are respectively obliquely connected between the long horizontal sleeve and the vertical connecting rod, and between the short horizontal sleeve and the vertical connecting rod, to enhance the strength.

[0010] The hydraulic motor is a low-speed hydraulic motor with a rotation speed of 20-120 rpm, a maximum torque of 410 N·m, and a maximum pressure of 7 MPa.

[0011] The maintenance cylinder is a hollow cylindrical structure made of lightweight and high-strength metal material and open at the top and bottom; at least two windows are evenly opened on the central side wall; the inner side wall of the connection end of the maintenance cylinder and the hydraulic motor is provided with a four-sided docking interface matching the output shaft of the hydraulic motor, and a plurality of slots for connecting with the cleaning mechanism are arranged parallel to the axial direction on the inner side wall of the other end of the maintenance cylinder, and a thread connected with the connecting mechanism is arranged on the outer side wall of this end.

[0012] The cleaning mechanism comprises at least two copper wire maintenance heads; the copper wire maintenance heads comprise a plug plate and copper wires; the plug plate is an arc-shaped structure bent from a rectangular plate, and the plug plate is plugged into the inner wall of the maintenance cylinder; a plurality of copper wires are fixedly connected to the inner surface of the arc-shaped rectangular plate.

[0013] The connection mechanism comprises a connection ring; the connection ring is threadedly connected to the outer side wall of the maintenance cylinder; at least two nuts are evenly connected to the outer side wall of the connection ring; and a fixing pin is threadedly connected to each nut.

[0014] A wellhead valve maintenance system comprises at least a device for wellhead valve maintenance; it also comprises an integrated hydraulic pump and a hydraulic extension pipe; the integrated hydraulic pump is connected to a hydraulic motor via the hydraulic extension pipe to provide power for the hydraulic motor.

[0015] A method for using a wellhead valve maintenance system, using the wellhead valve maintenance system, comprises the following steps:

[0016] Step 1: Connect the integrated hydraulic pump to the hydraulic motor through the hydraulic extension pipe;

[0017] Step 2: Quickly connect the output shaft of the hydraulic motor to the square docking port in the maintenance cylinder;

[0018] Step 3: Insert the fixing pin on the connecting mechanism into the handwheel of the valve to be maintained; if the valve is being opened and closed for maintenance, proceed to step 4; if the valve is being opened and closed for non-maintenance purposes, proceed to step 5;

[0019] Step 4: Insert the multiple copper wire maintenance heads in the cleaning mechanism into the slots in the maintenance cylinder so that they can rotate with the maintenance cylinder;

[0020] Step 5: Insert the long horizontal sleeve or the short horizontal sleeve in the fixing rod into the fixing handle, and place the short horizontal sleeve or the long horizontal sleeve on other valves of the gas tree to fix the hydraulic motor and prevent it from rotating in the opposite direction;

[0021] Step 6: Control the forward and reverse flow of the hydraulic oil by adjusting the integrated hydraulic pump, so that the drive shaft of the hydraulic motor rotates clockwise or counterclockwise, thereby opening or closing the valve.

[0022] Beneficial effects:

[0023] (1) The present invention is used for the maintenance of valves in a natural gas wellhead gas tree. The maintenance device of the present invention is composed of a hydraulic motor, a fixing mechanism, a maintenance cylinder, a connecting mechanism and a cleaning mechanism. Its use improves the efficiency of technical manual maintenance and reduces the intensity of work.

[0024] (2) The present invention uses hydraulic pumps and hydraulic motors to provide power, and manual work is completely replaced by mechanical work, which can reduce the labor intensity of maintenance work by more than 90%. An operator can easily complete the maintenance of a single valve within 10 minutes, and the operating efficiency is improved by more than 60%.

[0025] (3) The present invention is applicable to large-scale wellhead valve maintenance operations in the tight gas resource sector when the number of wells managed per capita is large.

[0026] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 It is a schematic diagram of the structure of the present invention;

[0029] Figure 2 It is an assembly schematic diagram of the present invention;

[0030] Figure 3 It is a schematic diagram of the cross-sectional structure of the maintenance cylinder in the present invention;

[0031] Figure 4 is a schematic diagram of the connection mechanism in the present invention;

[0032] Figure 5 It is a structural schematic diagram of the copper wire maintenance head of the present invention;

[0033] Figure 6 It is a structural schematic diagram of the fixing rod in the present invention.

[0034] In the figure: 1. hydraulic motor; 2. liquid inlet joint; 3. fixing handle; 4. fixing rod; 5. maintenance cylinder; 6. flat washer; 7. elastic washer; 8. fixing ear plate; 9. fixing pin; 10. copper wire maintenance head; 11. slot; 12. square docking port; 13. thread; 14. long horizontal sleeve; 15. short horizontal sleeve; 16. vertical connecting rod; 17. diagonal support rod; 18. connecting ring; 19. nut; 20. integrated hydraulic pump; 21. hydraulic extension pipe; 22. fixing frame; 23. copper wire; 24. plug plate; 25. liquid outlet joint. DETAILED DESCRIPTION

[0035] 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.

[0036] Embodiment 1:

[0037] according to Figure 1-Figure 6 A maintenance device for a wellhead valve shown in the figure comprises a hydraulic motor 1, a fixing mechanism, a maintenance cylinder 5, a connecting mechanism and a cleaning mechanism; one end of the maintenance cylinder 5 is connected to the hydraulic motor 1, the other end of the maintenance cylinder 5 is connected to the connecting mechanism, and the cleaning mechanism is connected to the inner side wall of the upper end of the maintenance cylinder 5; the fixing mechanism, the liquid inlet joint 2 and the liquid outlet joint 25 are connected to the side wall of the hydraulic motor 1.

[0038] In actual use, the integrated hydraulic pump 20 is connected to the inlet and outlet joints 2 and the outlet joint 25 on the hydraulic motor 1 through the hydraulic extension tube 21; then the output shaft of the hydraulic motor 1 is plugged into the maintenance cylinder 5; thereafter, the connecting mechanism is inserted into the handwheel of the valve to be maintained, so as to drive the handwheel to rotate; if the switch operation of the imported valve maintenance is performed, the cleaning mechanism is plugged into the maintenance cylinder 5 so that it can rotate with the maintenance cylinder 5; the present invention is placed on other valves of the gas tree through the fixing mechanism so that the hydraulic motor 1 is fixed and does not rotate in the reverse direction; then the integrated hydraulic pump 20 is adjusted to control the forward and reverse flow of the hydraulic oil, so that the transmission shaft of the hydraulic motor 1 rotates clockwise or counterclockwise, thereby opening or closing the valve, and the cleaning mechanism rotates with the maintenance cylinder 5 to clean and maintain the wellhead valve. If the valve switch operation other than maintenance is performed, the cleaning mechanism in the maintenance cylinder 5 is not installed or removed, and the other processes remain unchanged, and the valve can be opened or closed.

[0039] The present invention improves the maintenance efficiency of the wellhead valve by technical workers and reduces the work intensity.

[0040] The present invention adopts hydraulic pumps and hydraulic motors to provide power, and manual work is completely replaced by mechanical work, reducing the labor intensity of maintenance work by more than 90%. An operator can easily complete the maintenance of a single valve within 10 minutes, and the operating efficiency is improved by more than 60%.

[0041] The present invention can be adapted to large-scale wellhead valve maintenance operations in tight gas resource sectors when the number of wells managed per capita is large.

[0042] Embodiment 2:

[0043] according to Figure 1-Figure 3 , Figure 6 The maintenance device for a wellhead valve shown in the figure is different from the first embodiment in that: the fixing mechanism includes a fixing handle 3, a fixing rod 4 and a fixing ear plate 8; the fixing handle 3 is connected to the hydraulic motor 1 through a fixing member, the fixing handle 3 is connected to the fixing ear plate 8, and the fixing rod 4 is inserted into the fixing handle 3.

[0044] In actual use, the fixing mechanism is to fix the hydraulic motor 1 in the wellhead valve maintenance device to prevent it from rotating in the reverse direction after connecting the hydraulic motor 1 to other valves of the gas tree.

[0045] In specific application, the long horizontal sleeve 14 or the short horizontal sleeve 15 in the fixing rod 4 is plugged into the fixing handle 3, and the short horizontal sleeve 15 or the long horizontal sleeve 14 is placed on other valves of the gas tree, so that the hydraulic motor 1 is fixed.

[0046] The fixed handle 3 in this embodiment includes a ring and two handle bars, the two handle bars are horizontally and oppositely arranged on the side wall of the ring, and the ring is connected to the side wall of the hydraulic motor 1. When in use, according to the actual needs of the site, the fixed rod 4 is inserted to which side the handle bar has a suitable operating distance.

[0047] The adoption of the above technical solution realizes the fixing of the hydraulic motor 1 simply and conveniently.

[0048] Embodiment three:

[0049] according to Figure 1 The maintenance device for a wellhead valve shown in the figure is different from the second embodiment in that: the fixing part includes a flat washer 6, an elastic washer 7 and a bolt; the bolt connects the fixing ear plate 8 to the fixing handle 3 through a thread, and the flat washer 6 and the elastic washer 7 are placed between the bolt and the fixing ear plate 8.

[0050] In actual use, the fixing member adopts the above technical solution, which can not only connect the fixing handle 3 to the hydraulic motor 1 conveniently, quickly and stably, but also will not cause damage to the hydraulic motor 1.

[0051] Embodiment 4:

[0052] according to Figure 1-Figure 3 , Figure 6 The maintenance device for a wellhead valve shown in the figure is different from the second embodiment in that: the fixing rod 4 includes a vertical connecting rod 16, a long horizontal sleeve 14, a short horizontal sleeve 15 and two diagonal support rods 17; the long horizontal sleeve 14 and the short horizontal sleeve 15 have different lengths; the long horizontal sleeve 14 and the short horizontal sleeve 15 are arranged in parallel, and the long horizontal sleeve 14 and the short horizontal sleeve 15 are respectively vertically connected to the upper and lower ends of the opposite sides of the vertical connecting rod 16; the two diagonal support rods 17 are respectively obliquely connected between the long horizontal sleeve 14 and the vertical connecting rod 16, and between the short horizontal sleeve 15 and the vertical connecting rod 16, for enhancing strength.

[0053] In actual use, the vertical connecting rod 16, the long horizontal sleeve 14, the short horizontal sleeve 15 and the two diagonal braces 17 form an integrated fixed rod 4. According to the actual situation on site, the long horizontal sleeve 14 or the short horizontal sleeve 15 is inserted into the fixed handle 3, and the short horizontal sleeve 15 or the long horizontal sleeve 14 is placed on other valves of the gas tree to fix the hydraulic motor 1 to prevent the hydraulic motor 1 from rotating in the opposite direction.

[0054] In specific applications, in order to ensure the stability of the connection between the long horizontal sleeve 14 , the short horizontal sleeve 15 and the fixed rod 4 , a slot matching the fixed handle 3 is provided on the inner wall of the long horizontal sleeve 14 and the short horizontal sleeve 15 .

[0055] Embodiment five:

[0056] according to Figure 1-Figure 3 The maintenance device for a wellhead valve shown in the figure is different from the first embodiment in that the hydraulic motor 1 is a low-speed hydraulic motor with a rotation speed of 20-120 rpm, a maximum torque of 410 N·m, and a maximum pressure of 7 MPa.

[0057] In actual use, since the wellhead valve and the upstream and downstream pipelines are filled with high-pressure media, the speed should not be too fast when using the tool for switch operation to avoid sudden pressure release and cause overpressure or leakage accidents; furthermore, due to the tight structure of the valve, the speed should not be too fast when using the tool for switch operation to avoid damaging the internal sealing components and causing valve damage. In addition, the hydraulic motor used has the characteristics of low speed and high torque; its high torque characteristics can meet the requirements of on-site operation parameters.

[0058] The adoption of this technical solution can ensure that the power of the motor is sufficient to open and close the valve, while preventing other damages caused by excessive speed or power.

[0059] Embodiment six:

[0060] according to Figure 1-Figure 3 The maintenance device for a wellhead valve shown in the figure is different from the first embodiment in that: the maintenance cylinder 5 is a hollow cylindrical structure made of a lightweight and high-strength metal material and is open at the top and bottom; at least two windows are evenly opened on the central side wall; a square docking port 12 matching the output shaft of the hydraulic motor 1 is provided on the inner side wall of the connection end of the maintenance cylinder 5 and the hydraulic motor 1, and a plurality of slots 11 for connecting to the cleaning mechanism are provided on the inner side wall of the other end of the maintenance cylinder 5 in parallel along the axial direction, and a thread 13 connected to the connecting mechanism is provided on the outer side wall of this end.

[0061] In actual use, the slot 11 is used to plug in the copper wire maintenance head 10 as a cleaning mechanism, making the connection and removal of the copper wire maintenance head 10 more convenient.

[0062] In this embodiment, the lightweight and high-strength metal material used in the maintenance cylinder 5 is a high-strength aluminum alloy with good flexibility. In specific applications, other lightweight and high-strength materials with good flexibility can also be used.

[0063] Embodiment seven:

[0064] according to Figure 2 and Figure 5 The maintenance device for a wellhead valve shown in the figure is different from the first embodiment in that: the cleaning mechanism includes at least two copper wire maintenance heads 10; the copper wire maintenance head 10 includes a plug plate 24 and a copper wire 23; the plug plate 24 is an arc-shaped structure bent from a rectangular plate, and the plug plate 24 is plugged into the inner wall of the maintenance tube 5; a plurality of copper wires 23 are fixedly connected to the inner surface of the arc-shaped rectangular plate.

[0065] In actual use, the hydraulic motor 1 drives the copper wire maintenance head 10 to rotate, and the copper wire 23 inside the copper wire maintenance head 10 brushes the wellhead valve screw rod, stripping the oil and rust on the screw rod to achieve the purpose of maintenance.

[0066] In specific applications, the copper wire 23 in the copper wire maintenance head 10 can also be replaced by an insert-type copper wire brush, so that it can be taken out from the insert plate 24 for easy cleaning and replacement.

[0067] In specific applications, the copper wire 23 in the copper wire maintenance head 10 surrounds the wellhead valve screw. When the hydraulic motor 1 rotates, the copper wire 23 can play a good cleaning role on the wellhead valve screw.

[0068] The copper wire maintenance head 10 in this embodiment adopts a plug-in type copper wire maintenance head, which can clean the valve screw while opening and closing the valve. After the copper wire maintenance head 10 is dirty or damaged, it can be quickly disassembled and replaced. It has the characteristics of low operating cost and no need to replace major components, which makes maintenance efficiency higher.

[0069] Embodiment eight:

[0070] according to Figure 1 , Figure 2 and Figure 4 The maintenance device for a wellhead valve shown in the figure is different from the first embodiment in that: the connecting mechanism includes a connecting ring 18; the connecting ring 18 is threadedly connected to the outer wall of the maintenance tube 5; at least two nuts 19 are evenly connected to the outer wall of the connecting ring 18; and a fixing pin 9 is threadedly connected to each nut 19.

[0071] In actual use, the fixing pin 9 in the connecting mechanism is continuously rotated to insert the fixing pin 9 into the valve handwheel, thereby driving the handwheel to realize the opening and closing of the rotary wellhead valve, laying the foundation for the subsequent cleaning and maintenance of the wellhead valve.

[0072] The connecting mechanism is connected to the maintenance cylinder 5 via threads, which is convenient for disassembly and installation.

[0073] Embodiment nine:

[0074] according to Figure 3 The wellhead valve maintenance system shown includes at least a device for wellhead valve maintenance; it also includes an integrated hydraulic pump 20 and a hydraulic extension pipe 21; the integrated hydraulic pump 20 is connected to the hydraulic motor 1 through the hydraulic extension pipe 21 to provide power for the hydraulic motor 1.

[0075] In actual use, the integrated hydraulic pump 20 is connected to the fixing frame 22. In order to facilitate the movement of the wellhead valve maintenance device, the integrated hydraulic pump 20 is placed on a carrier, which is generally a light pickup truck. After arriving at the maintenance site, the integrated hydraulic pump 20 and the hydraulic motor 1 are connected through the hydraulic extension pipe 21 to carry out subsequent operations, making the wellhead valve maintenance operation easier and faster, and having the characteristics of adapting to inter-well transportation and wellhead layout.

[0076] Embodiment ten:

[0077] Reference Figure 1-Figure 6 A method for using a maintenance system for a wellhead valve, using the maintenance system for the wellhead valve, comprises the following steps:

[0078] Step 1: Connect the integrated hydraulic pump 20 to the hydraulic motor 1 through the hydraulic extension pipe 21;

[0079] Step 2: Quickly connect the output shaft of the hydraulic motor 1 to the square docking port 12 in the maintenance cylinder 5;

[0080] Step 3: Insert the fixing pin 9 on the connecting mechanism into the hand wheel of the valve to be maintained; if the switch operation of the imported valve maintenance is being carried out, proceed to step 4; if the valve switch operation is not being carried out for maintenance, proceed to step 5;

[0081] Step 4: insert the multiple copper wire maintenance heads 10 in the cleaning mechanism into the slots 11 in the maintenance cylinder 5 so that they can rotate together with the maintenance cylinder 5;

[0082] Step 5: Insert the long horizontal sleeve 14 or the short horizontal sleeve 15 in the fixing rod 4 into the fixing handle 3, and place the short horizontal sleeve 15 or the long horizontal sleeve 14 on other valves of the gas tree to fix the hydraulic motor 1 and prevent it from rotating in the opposite direction;

[0083] Step 6: By adjusting the integrated hydraulic pump 20, the forward and reverse flows of the hydraulic oil are controlled to make the transmission shaft of the hydraulic motor 1 rotate clockwise or counterclockwise, thereby opening or closing the valve.

[0084] In actual use, during the wellhead valve maintenance operation, the integrated hydraulic pump 20 placed on the carrier provides hydraulic power, and the hydraulic oil is transported to the valve of the gas tree that needs maintenance in the well field within 30 meters through the hydraulic extension pipe 21, and the hydraulic motor 1 is connected to convert the hydraulic energy into the kinetic energy of the rotary valve. The hydraulic motor output shaft of the hydraulic motor 1 is quickly plugged into the four-way docking interface 12 in the maintenance cylinder 5, driving the maintenance cylinder 5 to rotate. Three fixing pins 9 are evenly distributed at 120° on the front end of the maintenance cylinder 5. The fixing pins 9 are inserted into the valve handwheel by rotating the fixing pins 9, thereby driving the handwheel to rotate. The copper wire maintenance head 10 is plugged into the slot 11 of the maintenance cylinder 5 and rotates with the maintenance cylinder 5 to clean the sludge on the valve screw rod. One end of the fixing rod 4 is plugged into the fixed handle 3, and the other end is placed on other valves of the gas tree, so that the fixed hydraulic motor 1 is fixed and does not rotate in the opposite direction. By adjusting the integrated hydraulic pump, the forward and reverse flow of the hydraulic oil is controlled, and the hydraulic motor drive shaft rotates clockwise or counterclockwise to open or close the valve.

[0085] In the non-maintenance valve switch operation, the copper wire maintenance head 10 in the slot 11 in the maintenance cylinder 5 is removed, and the valve can be opened or closed according to the above operation.

[0086] The invention is used for the maintenance of valves in a natural gas wellhead gas production tree. The use of the invention improves the efficiency of technical manual maintenance and reduces the intensity of work.

[0087] The present invention adopts hydraulic pumps and hydraulic motors to provide power, and manual work is completely replaced by mechanical work, which can reduce the labor intensity of maintenance work by more than 90%. One operator can easily complete the maintenance of a single valve within 10 minutes, and the operating efficiency is improved by more than 60%.

[0088] The present invention can be adapted to large-scale wellhead valve maintenance operations in tight gas resource sectors when the number of wells managed per capita is large.

[0089] In the absence of conflicts, technicians in this field can combine the relevant technical features in the above examples according to actual conditions to achieve corresponding technical effects. The specific combinations are not described here one by one.

[0090] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0091] In addition, the descriptions of "first", "second", etc. in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0092] The above are only preferred embodiments of the present invention. The present invention will not be limited to the embodiments shown herein, but should conform to the widest scope consistent with the principles and novel features disclosed herein. Any simple modification, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A maintenance device for a wellhead valve, characterized in that: The invention comprises a hydraulic motor (1), a fixing mechanism, a maintenance cylinder (5), a connecting mechanism and a cleaning mechanism; one end of the maintenance cylinder (5) is connected to the hydraulic motor (1), the other end of the maintenance cylinder (5) is connected to the connecting mechanism, and the cleaning mechanism is connected to the inner side wall of the upper end of the maintenance cylinder (5); the fixing mechanism, a liquid inlet joint (2) and a liquid outlet joint (25) are connected to the side wall of the hydraulic motor (1).

2. A maintenance device for a wellhead valve according to claim 1, characterized in that: The fixing mechanism comprises a fixing handle (3), a fixing rod (4) and a fixing ear plate (8); the fixing handle (3) is connected to the hydraulic motor (1) via a fixing member, the fixing handle (3) is connected to the fixing ear plate (8), and the fixing rod (4) is plugged into the fixing handle (3).

3. A maintenance device for a wellhead valve according to claim 2, characterized in that: The fixing member comprises a flat washer (6), an elastic washer (7) and a bolt; the bolt connects the fixing ear plate (8) to the fixing handle (3) through a thread, and the flat washer (6) and the elastic washer (7) are arranged between the bolt and the fixing ear plate (8).

4. A maintenance device for a wellhead valve according to claim 2, characterized in that: The fixing rod (4) comprises a vertical connecting rod (16), a long horizontal sleeve (14), a short horizontal sleeve (15) and two diagonal bracing rods (17); the long horizontal sleeve (14) and the short horizontal sleeve (15) are of different lengths; the long horizontal sleeve (14) and the short horizontal sleeve (15) are arranged in parallel, and the long horizontal sleeve (14) and the short horizontal sleeve (15) are respectively vertically connected to the upper and lower ends of the opposite sides of the vertical connecting rod (16); the two diagonal bracing rods (17) are respectively obliquely connected between the long horizontal sleeve (14) and the vertical connecting rod (16), and between the short horizontal sleeve (15) and the vertical connecting rod (16) to enhance strength.

5. A maintenance device for a wellhead valve according to claim 1, characterized in that: The hydraulic motor (1) is a low-speed hydraulic motor with a rotation speed of 20-120 rpm, a maximum torque of 410 N·m, and a maximum bearing pressure of 7 MPa.

6. A maintenance device for a wellhead valve as claimed in claim 1, characterized in that: The maintenance cylinder (5) is a hollow cylindrical structure made of a light and high-strength metal material and open at the top and bottom; at least two windows are evenly arranged on the central side wall; a square docking port (12) matching the output shaft of the hydraulic motor (1) is arranged on the inner side wall of the connection end of the maintenance cylinder (5) and the hydraulic motor (1); a plurality of slots (11) for connecting to a cleaning mechanism are arranged parallel to the axial direction on the inner side wall of the other end of the maintenance cylinder (5); and a thread (13) connected to the connecting mechanism is arranged on the outer side wall of the end.

7. A maintenance device for a wellhead valve as claimed in claim 1, characterized in that: The cleaning mechanism comprises at least two copper wire maintenance heads (10); the copper wire maintenance head (10) comprises a plug plate (24) and copper wires (23); the plug plate (24) is an arc-shaped structure bent from a rectangular plate, and the plug plate (24) is plugged into the inner side wall of the maintenance cylinder (5); a plurality of copper wires (23) are fixedly connected to the inner surface of the arc-shaped rectangular plate.

8. A maintenance device for a wellhead valve according to claim 1, characterized in that: The connection mechanism comprises a connection ring (18); the connection ring (18) is threadedly connected to the outer wall of the maintenance cylinder (5); at least two nuts (19) are evenly connected to the outer wall of the connection ring (18); and each nut (19) is threadedly connected to a fixing pin (9).

9. A wellhead valve maintenance system, characterized in that: The invention comprises at least a device for maintaining a wellhead valve as described in any one of claims 1 to 8; and further comprises an integrated hydraulic pump (20) and a hydraulic extension pipe (21); the integrated hydraulic pump (20) is connected to a hydraulic motor (1) via the hydraulic extension pipe (21) to provide power for the hydraulic motor (1).

10. A method for using a wellhead valve maintenance system, characterized in that: The maintenance system for a wellhead valve according to claim 9 comprises the following steps: Step 1: Connect the integrated hydraulic pump (20) to the hydraulic motor (1) via a hydraulic extension pipe (21); Step 2: Quickly connect the output shaft of the hydraulic motor (1) to the square docking port (12) in the maintenance cylinder (5); Step 3: Insert the fixing pin (9) on the connecting mechanism into the hand wheel of the valve to be maintained; if the valve is being opened and closed for maintenance, proceed to step 4; if the valve is being opened and closed for non-maintenance purposes, proceed to step 5; Step 4: insert the plurality of copper wire maintenance heads (10) in the cleaning mechanism into the slots (11) in the maintenance cylinder (5) so that the copper wire maintenance heads (10) can rotate together with the maintenance cylinder (5); Step 5: Insert the long horizontal sleeve (14) or the short horizontal sleeve (15) in the fixing rod (4) into the fixing handle (3), and place the short horizontal sleeve (15) or the long horizontal sleeve (14) on other valves of the gas tree to fix the hydraulic motor (1) and prevent it from rotating in the opposite direction; Step 6: By adjusting the integrated hydraulic pump (20), the forward and reverse flows of the hydraulic oil are controlled so that the transmission shaft of the hydraulic motor (1) rotates clockwise or counterclockwise, thereby opening or closing the valve.

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