A wellhead Christmas tree pressure retaining valve changing device without releasing

Abstract

The present application relates to gas tree valve replacement maintenance technical field, disclose a kind of wellhead gas tree does not lose hand pressure valve replacement device, including plugging assembly, feed-in lifting assembly and support assembly, plugging assembly includes coaxially arranged shell, limiting sleeve, second cylinder, rubber cylinder assembly, guide shoe, mandrel, spring, first cylinder, piston, lifting assembly includes with plugging assembly coaxially arranged pressurizing pipe, lifting cylinder and lifting piston, support assembly includes support plate and support rod, it is when applied, support assembly is used to be connected with valve seat to form counterforce support, lifting assembly can be used to plugging assembly pressurization and for the dismounting of valve piece, plugging assembly when pressurization its rubber cylinder assembly axial compression and radial expansion, by rubber cylinder assembly and pipeline inner wall expansion tight seal to realize pressure valve replacement, stop pressurization, under the action of spring and rubber cylinder assembly self elastic force, can play to pressure-maintaining effect, keep the reliability of sealing plugging, after completing valve replacement, can directly jolt mandrel to decompression unsealing.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas tree valve replacement maintenance, in particular to a wellhead gas tree non-loose pressure valve replacement device. BACKGROUND

[0002] The gas tree refers to the general term of the part above the pipe head of the wellhead device, mainly composed of the wellhead cross and the main control valve (total gate, pipeline gate, needle valve, pressure measuring gate, casing gate, etc.), and is the main device for opening and closing the well, adjusting the pressure, measuring the pressure with the pressure gauge, and measuring the wellhead pressure.

[0003] Since the wellhead device directly controls the collection of natural gas in the well under high pressure, it is in working condition as soon as it is installed, so it is extremely difficult to maintain and replace the main control valve. The traditional replacement method is to first use well killing fluid to perform well killing operation on the construction well, and then replace the main control valve of the wellhead when the well killing is stable. This traditional method has the problems of long construction period, multiple equipment, large workload, multiple collaborative construction units, multiple participants, serious environmental pollution caused by discharge of well killing fluid, and high construction cost. At the same time, this traditional method also causes secondary damage to the well bottom formation, especially for old wells in the middle and late production period, as the formation energy is low, it is difficult to restore to the original production after well killing, and some wells may be killed and lose production capacity to become waste wells.

[0004] In order to overcome the defects of the traditional replacement method, the technical personnel in the field have been committed to researching the replacement form of the valve under pressure. At present, we use the way of kava positioning card point to replace the valve or maintain, which seals the kava installed in a fixed point of the inner wall of the pipe head in front of the valve to be replaced, disconnects the valve to be replaced from the gas tree pipeline for replacement; but in actual application, due to the corrosion of the pipe head flow channel by acid medium for a long time, the inner wall is often uneven, it is difficult to select the card point position, the connection and sealing reliability of the kava and the inner wall after installation is poor, and there is a safety hazard in the subsequent valve replacement operation. It is also difficult to remove and take out the kava after the valve replacement operation. There are many forms of devices for pipe head plugging in the prior art in other fields, but these devices are difficult to meet the use requirements of reliable sealing, easy unsealing, and convenient operation when used for gas tree valve replacement under pressure.

[0005] In addition, the main control valve and the pipe head in the gas tree are usually connected in the form of flange, and the valve replacement link in the existing method is generally manually disassembled and assembled, and the valve needs to be lifted to align the flange before installing the new valve. Since the main control valve in the gas tree is heavy, it is very time-consuming and laborious to align and install the new valve. SUMMARY

[0006] The wellhead gas production tree non-loose pressure valve replacement device can plug the front end pipe head of the valve to be replaced to realize pressure valve replacement, and the whole valve replacement operation process is extremely labor-saving and convenient.

[0007] The purpose of the present application is achieved by the following technical solutions:

[0008] A wellhead gas production tree non-loose pressure valve replacement device, comprising a plugging assembly, a feeding and lifting assembly and a supporting assembly;

[0009] The plugging assembly comprises a housing, a limiting sleeve, a second cylinder, a rubber cylinder assembly, a guide shoe, a mandrel, a spring, a first cylinder and a piston, the housing is a hollow column structure with open ends, the limiting sleeve is fixedly arranged in the middle part of the housing, one end of the second cylinder is slidably arranged in one end of the housing, the other end of the second cylinder is fixedly connected with the guide shoe, the rubber cylinder assembly is sleeved outside the second cylinder, and the two ends of the rubber cylinder assembly are respectively abutted with the end of the housing and the end of the guide shoe; a first core hole and a first pressure transmission hole are formed in the end of the limiting sleeve away from the guide shoe, a small-diameter hole and a large-diameter hole are sequentially formed in the limiting sleeve along the axis towards the other end, the two ends of the first pressure transmission hole are respectively communicated with the small-diameter hole and the inner cavity of the end of the housing away from the second cylinder, the junction part of the small-diameter hole and the large-diameter hole forms a tapered sealing table, one end of the first cylinder is fixedly arranged in the end of the large-diameter hole away from the small-diameter hole and is provided with a second core hole and a second pressure transmission hole, the other end of the first cylinder is fixedly connected with the piston, the two ends of the second pressure transmission hole are respectively communicated with the large-diameter hole and the inner cavity of the first cylinder, the outer wall of the first cylinder is slidably matched with the end of the second cylinder away from the guide shoe, the piston is slidably matched with the inner wall of the second cylinder, the inner cavity of the second cylinder is divided into a rod cavity and a rodless cavity by the piston, the rod cavity is arranged on the side of the piston close to the first cylinder, a third pressure transmission hole is formed in the side wall of the first cylinder, the two ends of the third pressure transmission hole are respectively communicated with the rod cavity and the inner cavity of the first cylinder, a flow channel hole is formed in the guide shoe, the two ends of the flow channel hole are respectively communicated with the rodless cavity and the side of the guide shoe away from the second cylinder, a tapered block is fixedly sleeved on the mandrel, one end of the mandrel is slidably arranged in the first core hole, the other end of the mandrel is slidably arranged in the second core hole, the tapered block is arranged in the large-diameter hole, the tapered block is matched with the tapered sealing table, and the spring is sleeved on the mandrel, the two ends of the spring are respectively abutted with the tapered block and the end of the first cylinder.

[0010] The feeding and lifting assembly comprises coaxially arranged a pressurizing pipe, a lifting cylinder and a lifting piston, the pressurizing pipe penetrates through the lifting cylinder and is slidably fitted at both ends of the lifting cylinder, the lifting piston is fixedly sleeved on the pressurizing pipe, and the lifting piston is slidably arranged in the lifting cylinder; two lifting oil ports are respectively arranged at both ends of the lifting cylinder and are in communication with the inside of the lifting cylinder.

[0011] The support assembly comprises a support plate and a support rod, the support plate is detachably connected with one end of the support rod, and an internally threaded oil injection hole is formed in the support plate and penetrates through the support plate.

[0012] One end of the pressurizing pipe is threadedly connected with the internally threaded oil injection hole, and the other end of the pressurizing pipe is threadedly connected with the end of the shell away from the second cylinder.

[0013] Further, a hollow butt flange is further arranged, one end of the butt flange is threadedly sleeved on the end of the lifting cylinder close to the plugging assembly, and the other end of the butt flange is matched with the valve to be replaced.

[0014] Further, a large four-way valve seat is further arranged, and the end of the support rod away from the support plate is connected with the large four-way valve seat through bolts.

[0015] Specifically, the support rod has a plurality of support rods, and the plurality of support rods are circumferentially arranged.

[0016] Specifically, sealing rings are arranged between the mandrel and the first core hole, between the mandrel and the second core hole, between the outer wall of the first cylinder and the end of the second cylinder away from the guide shoe, between the piston and the inner wall of the second cylinder, between the lifting piston and the inner wall of the lifting cylinder, and between the pressurizing pipe and both ends of the lifting cylinder.

[0017] Specifically, the rubber tube assembly comprises a plurality of rubber tubes, and the plurality of rubber tubes are sequentially sleeved outside the second cylinder, and a spacer ring is arranged between adjacent two rubber tubes.

[0018] Further, a taking-out pipe and a poking rod are further arranged, one end of the taking-out pipe is threadedly fitted with the end of the shell away from the second cylinder, the poking rod is movably arranged in the taking-out pipe, and one end of the poking rod is matched with the end of the mandrel away from the first cylinder.

[0019] The wellhead gas production tree without losing pressure valve replacement device can plug the front end pipe of the valve to be replaced to realize pressure valve replacement, and the whole valve replacement operation process is extremely labor-saving and convenient.

[0020] The wellhead gas production tree without losing pressure valve replacement device can plug the front end pipe of the valve to be replaced to realize pressure valve replacement, and the whole valve replacement operation process is extremely labor-saving and convenient.

[0021] The purpose of the present application is achieved by the following technical solutions:

[0022] The wellhead gas production tree non-loose pressure valve changing device comprises a plugging assembly, a feeding and lifting assembly and a supporting assembly. The plugging assembly comprises a housing, a limiting sleeve, a second cylinder, a rubber cylinder assembly, a guide shoe, a mandrel, a spring, a first cylinder and a piston. The limiting sleeve is fixedly arranged in the middle of the housing. One end of the second cylinder is slidably arranged in one end of the housing. The other end of the second cylinder is fixedly connected with the guide shoe. The rubber cylinder assembly is sleeved on the second cylinder. The two ends of the rubber cylinder assembly are respectively abutted with the end of the housing and the end of the guide shoe. One end of the first cylinder is fixedly arranged in one end of the limiting sleeve. The cylinder body of the first cylinder is slidably arranged in one end of the second cylinder. The other end of the first cylinder is fixedly connected with the piston. The piston is slidably arranged in the second cylinder. The mandrel is slidably arranged in the limiting sleeve. A conical block is sleeved on the mandrel. A conical surface limiting table is arranged in the limiting sleeve. The spring is used to provide elastic force to press the conical block on the conical surface limiting table. A first pressure transmission hole is arranged on the limiting sleeve. A second pressure transmission hole and a third pressure transmission hole are arranged on the first cylinder. The feeding and lifting assembly comprises a pressurizing pipe. One end of the pressurizing pipe is threadedly connected with the end of the housing away from the second cylinder. The supporting assembly comprises a supporting plate and a supporting rod. In use, the supporting rod is connected with the valve seat for supporting. The other end of the pressurizing pipe is threadedly connected with the supporting plate. Through the pressurizing pipe, hydraulic oil enters the first pressure transmission hole, pushes away the conical block, then enters the second pressure transmission hole, the first cylinder cavity and the third pressure transmission hole in sequence, and then enters the rod cavity of the second cylinder, thereby driving the second cylinder and the guide shoe to move axially, making the rubber cylinder assembly compress axially and expand radially, until the rubber cylinder assembly is tightly sealed with the inner wall of the pipeline. After stopping pressurizing, the spring and the elastic force of the rubber cylinder assembly can keep the pressure, maintain the reliability of the sealing and plugging, thereby realizing the pressure valve changing.

[0023] The feeding and lifting assembly further comprises a lifting cylinder and a lifting piston coaxially arranged with the pressurizing pipe. The lifting cylinder and the lifting piston are integrally arranged in the structure of the hydraulic cylinder with the piston rod extending from both ends. The pressurizing pipe is similar to the piston rod. After the connection with the flange, the valve to be replaced or the newly installed valve can be moved through the hydraulic form during the replacement of the valve, so that the disassembly and assembly of the valve are more labor-saving and convenient.

[0024] A taking-out pipe and a poking rod are further arranged. After the valve replacement is completed, the poking rod can be directly used to push the mandrel to realize the pressure relief and unsealing. The plugging assembly can be taken out as a whole by lifting the taking-out pipe, so that the unsealing and taking-out operations are extremely convenient. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a whole structure sectional view of the wellhead gas production tree non-loose pressure valve changing device.

[0026] Figure 2 It is a sectional view of the plugging assembly in the wellhead gas production tree non-loose pressure valve changing device.

[0027] Figure 3 As Figure 2 An enlarged view of the middle A part;

[0028] Figure 4 It is the cross-sectional structure schematic diagram of the running and lifting assembly in the wellhead gas production tree non-loose pressure valve changing device of the application;

[0029] Figure 5 It is the cross-sectional structure schematic diagram of the support assembly in the wellhead gas production tree non-loose pressure valve changing device of the application;

[0030] Figure 6 It is the cross-sectional structure schematic diagram of the butt flange in the support assembly in the wellhead gas production tree non-loose pressure valve changing device of the application;

[0031] Figure 7 It is the use state schematic diagram of the wellhead gas production tree non-loose pressure valve changing device of the application;

[0032] Figure 8 As Figure 7 The enlarged schematic diagram of the connection part of the running and lifting assembly and the support assembly in the use state shown;

[0033] Figure 9 As Figure 7 The enlarged schematic diagram of the connection part of the running and lifting assembly and the plugging assembly in the use state shown

[0034] In the figure, 1-large four-way valve seat, 2-valve, 100-plugging assembly, 101-housing, 102-limiting sleeve, 103-core shaft, 104-first cylinder, 105-second cylinder, 106-piston, 107-lead shoe, 108-rubber tube, 109-separation ring, 110-first pressure transmission hole, 111-small diameter hole, 112-large diameter hole, 113-second pressure transmission hole, 114-third pressure transmission hole, 115-flow channel hole, 116-cone block, 117-spring, 200-running and lifting assembly, 201-pressurizing pipe, 202-lifting cylinder, 203-lifting piston, 204-lifting oil port, 300-support assembly, 301-support plate, 302-support rod, 303-internal thread oil injection hole, 304-butt flange. DETAILED DESCRIPTION

[0035] The technical solutions of the application will be described in further detail below in combination with the drawings, but the protection scope of the application is not limited to the following description.

[0036] As Figures 1 to 5 shown, a wellhead gas production tree non-loose pressure valve changing device, comprising a plugging assembly 100, a running and lifting assembly 200 and a support assembly 300.

[0037] As Figure 2 , Figure 3As shown, the plugging assembly 100 comprises a housing 101, a limiting sleeve 102, a second cylinder 105, a rubber cylinder assembly, a guide shoe 107, a mandrel 103, a spring 117, a first cylinder 104 and a piston 106 arranged coaxially.

[0038] The housing 101 is a hollow column structure with both ends open, the limiting sleeve 102 is fixedly arranged in the middle of the housing 101, one end of the second cylinder 105 is slidably arranged in one end of the housing 101, the other end of the second cylinder 105 is fixedly connected with the guide shoe 107, the rubber cylinder assembly is sleeved on the second cylinder 105, and the two ends of the rubber cylinder assembly abut against the end of the housing 101 and the end of the guide shoe 107 respectively, when the second cylinder 105 slides towards the limiting sleeve 102, the guide shoe 107 can be axially slid to compress the rubber cylinder assembly axially and expand the rubber cylinder assembly radially. The limiting sleeve 102 is a hollow column structure with one end open, the end of the limiting sleeve 102 away from the guide shoe 107 is a closed end, a first core hole and a first pressure transmission hole 110 are formed on the closed end, a small-diameter hole 111 and a large-diameter hole 112 are sequentially formed in the limiting sleeve 102 along the axis towards the other end to form a hollow, an opening is formed on the other end of the large-diameter hole 112, a tapered sealing table is formed on the joint of the small-diameter hole 111 and the large-diameter hole 112, and the two ends of the first pressure transmission hole 110 are respectively communicated with the small-diameter hole 111 and the inner cavity of the end of the housing 101 away from the second cylinder 105. The first cylinder 104 is a cylinder structure, one end of the first cylinder 104 is a closed end, the closed end is fixedly arranged in the end of the large-diameter hole 112 away from the small-diameter hole 111 and a second core hole and a second pressure transmission hole 113 are formed on the end, the other end of the first cylinder 104 is fixedly connected with the piston 106, and the two ends of the second pressure transmission hole 113 are respectively communicated with the large-diameter hole 112 and the inner cavity of the first cylinder 104. The outer wall of the first cylinder 104 is slidably matched with the end of the second cylinder 105 away from the guide shoe 107, the piston 106 is slidably matched with the inner wall of the second cylinder 105, and the inner cavity of the second cylinder 105 is divided into a rod cavity and a rodless cavity by the piston 106, the rod cavity is arranged on the side of the piston 106 close to the first cylinder 104, a third pressure transmission hole 114 is formed on the side wall of the first cylinder 105, the two ends of the third pressure transmission hole 114 are respectively communicated with the rod cavity and the inner cavity of the first cylinder 104, a flow channel hole 115 is formed on the guide shoe 107, and the two ends of the flow channel hole 115 are respectively communicated with the rodless cavity and the side of the guide shoe 107 away from the second cylinder 105. A tapered block 116 is fixedly sleeved on the mandrel 103, one end of the mandrel 103 is slidably arranged in the first core hole, the other end of the mandrel 103 is slidably arranged in the second core hole, the tapered block 116 is arranged in the large-diameter hole 112, and the tapered block 116 is matched with the tapered sealing table. The spring 117 is sleeved on the mandrel 103, and the two ends of the spring 117 are respectively abutted against the tapered block 116 and the end of the first cylinder 104.

[0039] As shown in the figure, Figure 4As shown, the feeding and lifting assembly 200 comprises coaxially arranged pressurizing pipe 201, lifting cylinder 202 and lifting piston 203, the pressurizing pipe 201 is hollow tubular structure, the pressurizing pipe 201 penetrates through the lifting cylinder 202 and is slidably fitted with both ends of the lifting cylinder 202, the lifting piston 203 is fixedly sleeved on the pressurizing pipe 201, and the lifting piston 203 is slidably arranged in the lifting cylinder 202. Two lifting oil ports 204 are respectively arranged at both ends of the lifting cylinder 202 and are in communication with the inside of the lifting cylinder 202, hydraulic pipelines are respectively connected to the two lifting oil ports 204, and when oil is fed into one of the lifting oil ports 204, oil can be returned through the other lifting oil port 204, and when the pressurizing pipe 201 is fixed, the lifting cylinder 202 can be driven to move axially by pumping oil into one of the lifting oil ports 204.

[0040] As shown in the figure, Figure 5 The support assembly 300 comprises a support plate 301 and a support rod 302, the support plate 301 is detachably connected with one end of the support rod 302, and a through inner threaded oil injection hole 303 is arranged on the support plate 302.

[0041] When the whole is assembled, one end of the pressurizing pipe 201 is threadedly connected with the inner threaded oil injection hole 303, and the other end of the pressurizing pipe 201 is threadedly connected with the end of the shell 101 away from the second cylinder 105.

[0042] The wellhead gas tree pressure valve changing device can be used for pressure valve changing of the wellhead gas tree, replaces the traditional well killing valve changing form, and effectively solves the problems of long construction period, many devices used, large workload, many collaborative construction units, many participants, serious environmental pollution caused by discharge of well killing fluid, and high construction cost in the traditional valve changing mode.

[0043] As shown in the figure, Figures 7 to 9 Taking the replacement of the valve element 2 at the top end of the wellhead large four-way valve seat 1 as an example, the valve changing operation can be operated according to the following steps:

[0044] S1, assemble the wellhead gas tree pressure valve changing device according to the foregoing, connect the inner threaded oil injection hole 303 of the support plate 301 to the oil pumping pipeline, and connect the two lifting oil ports 204 to the oil supply pipeline.

[0045] S2, open the valve element 2 to be replaced, extend the plugging assembly 100 through the center of the valve element 2 to the pipeline pipe head position at the front end of the valve element 2, and then fix the end of the support rod 302 of the support assembly 300 away from the support plate 301 to the large four-way valve seat 1 by bolts.

[0046] S3, pump oil into the female threaded oil hole 303 to perform pressurization. When pressurized, hydraulic oil flows into the end of the housing 101 away from the shoe 107 through the inside of the pressurizing pipe 201, and then in the plug assembly 100, the hydraulic oil enters the small diameter hole 111 through the first pressure transmission hole 110, the pressure in the small diameter hole 111 rises, which acts on the tapered block 116 to drive the shaft 103 to move axially downward as a whole and compress the spring 117, at this time the tapered block 116 is separated from the conical sealing platform and a gap is formed, the hydraulic oil flows into the large diameter hole 112 from the gap, and then the hydraulic oil flows into the rod cavity of the second cylinder 105 in sequence through the second pressure transmission hole 113, the inner cavity of the first cylinder 104, and the third pressure transmission hole 114. During this process, the air and other media in the rodless cavity of the second cylinder 105 will be discharged from the flow channel hole 115 without obstruction, so that as the hydraulic oil in the rod cavity increases, it can drive the second cylinder 105 and the shoe 107 to move axially upward as a whole, so that the rubber tube assembly is axially compressed and radially expanded, until the outer wall of the rubber tube assembly is tightly expanded with the inner wall of the pipeline, and the plugging of the front end pipeline of the valve to be replaced is completed. Since the plugging tool is plugged by the expansion of the rubber tube assembly, the influence of the unevenness of the inner wall of the pipeline is small during use, which can effectively solve the problem of difficult selection of the sticking point.

[0047] S4, stop pressurization. When the pressurization is stopped, the spring 117 will rebound to press the tapered block 116 tightly on the conical sealing platform to form a seal, and the self elastic force of the rubber tube assembly also has a tendency to retract, which makes the second cylinder 105 and the shoe 107 move axially upward, thereby compressing the rod cavity of the second cylinder 105. The hydraulic oil in the rod cavity flows into the large diameter hole 112 in sequence through the third pressure transmission hole 114, the inner cavity of the first cylinder 104, and the second pressure transmission hole 113, and further acts on the tapered block 116 to maintain the stability of the seal at this position. As can be seen, after the pressurization is stopped, the plug assembly 100 inside forms an automatic pressure maintaining effect, which can effectively ensure the reliability of the pipeline plugging.

[0048] S5, disassemble the connecting bolts of the support plate 301 in the support assembly 300 to disconnect it from the support rod 302, then disconnect the pressurizing pipe 201 from the housing 101, then remove the feeding and lifting assembly 200, and then replace the valve 2. It should be noted that if the time and labor of manual replacement of the valve 2 are not considered, the connecting bolts of the support rod 302 in the support assembly 300 and the large four-way valve seat 1 can also be disassembled, and the support assembly 300 and the feeding and lifting assembly 200 can be removed as a whole to replace the valve 2.

[0049] S6, after the valve 2 is replaced, the connection is taken out of the assembly, the plug assembly 100 is taken out, and then the valve 2 is closed to complete the replacement operation. In specific implementation, the taking-out assembly includes a taking-out pipe and a poking rod. One end of the taking-out pipe is threadedly connected to the end of the housing 101 away from the second cylinder 105. The poking rod is movably arranged in the taking-out pipe. One end of the poking rod is adapted to the end of the mandrel 103 away from the first cylinder 104. In use, the one end of the taking-out pipe is first threaded through the installed valve 2 and is directly threadedly connected to the top end of the housing 101. Then, the poking rod is used to push the mandrel 103 to separate the conical block 116 from the conical sealing platform to complete pressure relief. Under the action of the aforementioned tendency force, the rubber cylinder assembly is retracted, thereby quickly achieving unsealing. Then, the plug tool can be taken out as a whole by lifting the taking-out pipe.

[0050] It should be understood that the above is only an embodiment of the wellhead large four-way valve seat top end valve replacement. The above operation process can be substantially applied to the replacement of valve seats of various types and valve parts installed in various directions of the valve seats. As can be seen from the above operation process, the wellhead gas production tree without pressure change valve device does not need well killing operation when used for valve replacement of the gas production tree. The device can achieve pressure change valve replacement, has the advantages of reliable sealing, easy unsealing, and relatively simple structure and convenient use.

[0051] Further, it further includes a hollow butt flange 304, the structure of which is shown in Figure 6 In use, one end of the butt flange 304 is threadedly sleeved on the end of the lifting cylinder 202 close to the plug assembly 100. The other end of the butt flange 304 is connected to the flange end of the valve 2 to be replaced. In the above step S5 of replacing the valve 2, in the dismounting stage of the valve 2, the lifting cylinder 202 can be driven to move axially upward by pumping oil to one lifting oil port 204. Since the valve 2 to be dismounted is fixedly connected to the lifting oil cylinder 202, the valve 2 can be conveniently separated from the large four-way valve seat 1 and lifted. In the mounting stage of the new valve 2, the new valve can be mounted on the feeding lifting assembly 200. After the feeding lifting assembly 200 is assembled with the supporting assembly 300 in the above manner, the lifting cylinder 202 is driven to move axially downward by pumping oil to the other lifting oil port 204. At this time, the hole alignment operation of the new valve 2 during installation on the large four-way valve seat 1 can be conveniently performed, thereby solving the problem of laborious installation of the new valve due to the large weight of the valve seat.

[0052] In specific implementation, the support rods 302 in the support assembly 300 are several, and the several support rods 302 are circumferentially and uniformly arranged. In use, the support assembly 300 has a cage structure as a whole, thereby ensuring the structural strength. The sealing rings are arranged between the mandrel 103 and the first core hole, between the mandrel 103 and the second core hole, between the outer wall of the first cylinder 104 and the end of the second cylinder 105 away from the guide shoe 107, between the piston 106 and the inner wall of the second cylinder 104, between the lifting piston 203 and the inner wall of the lifting cylinder 202, and between the pressurizing pipe 201 and the two ends of the lifting cylinder 202, so as to ensure the sealing and pressure transmission effects. The rubber tube assembly includes several rubber tubes 108, and the several rubber tubes 108 are sequentially sleeved outside the second cylinder 105. The spacer rings 109 are arranged between the adjacent two rubber tubes 108, thereby overcoming the unstable expansion sealing performance caused by the excessively large height-diameter ratio of the single rubber tube, and the multiple short-section rubber tubes can better ensure the sealing reliability.

[0053] The above description is only the preferred embodiments of the present application, and it should be understood that the present application is not limited to the forms disclosed herein, and should not be considered as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concepts described herein by the above teachings or related art or knowledge. Any modification and change made by those skilled in the art without departing from the spirit and scope of the present application shall be within the protection scope of the appended claims of the present application.

Claims

1. A wellhead Christmas tree pressure-containing valve changing device without releasing, characterized in that, The plugging assembly, the feeding and lifting assembly and the supporting assembly are included. The plugging assembly includes a housing, a limiting sleeve, a second cylinder, a rubber cylinder assembly, a guide shoe, a mandrel, a spring, a first cylinder and a piston, The housing is a hollow column structure with two open ends, the limiting sleeve is fixedly arranged in the middle of the housing, one end of the second cylinder is slidably arranged in one end of the housing, the other end of the second cylinder is fixedly connected with the guide shoe, the rubber cylinder assembly is sleeved outside the second cylinder, and the two ends of the rubber cylinder assembly are respectively abutted with the end of the housing and the end of the guide shoe, A first core hole and a first pressure transmission hole are formed in the end of the limiting sleeve away from the guide shoe, a small-diameter hole and a large-diameter hole are sequentially formed in the limiting sleeve along the axis towards the other end, the two ends of the first pressure transmission hole are respectively communicated with the small-diameter hole and the inner cavity of the end of the housing away from the second cylinder, and a taper sealing platform is formed at the junction of the small-diameter hole and the large-diameter hole, One end of the first cylinder is fixedly arranged in the end of the large-diameter hole away from the small-diameter hole and is provided with a second core hole and a second pressure transmission hole, the other end of the first cylinder is fixedly connected with the piston, and the two ends of the second pressure transmission hole are respectively communicated with the large-diameter hole and the inner cavity of the first cylinder, The outer wall of the first cylinder is slidably matched with the end of the second cylinder away from the guide shoe, the piston is slidably matched with the inner wall of the second cylinder, the inner cavity of the second cylinder is divided into a rod cavity and a rodless cavity by the piston, the rod cavity is arranged on the side of the piston close to the first cylinder, a third pressure transmission hole is formed in the side wall of the first cylinder, the two ends of the third pressure transmission hole are respectively communicated with the rod cavity and the inner cavity of the first cylinder, a flow channel hole is formed in the guide shoe, and the two ends of the flow channel hole are respectively communicated with the rodless cavity and the side of the guide shoe away from the second cylinder, A tapered block is fixedly sleeved on the mandrel, one end of the mandrel is slidably arranged in the first core hole, the other end of the mandrel is slidably arranged in the second core hole, the tapered block is arranged in the large-diameter hole, and the tapered block is matched with the taper sealing platform, The spring is sleeved on the mandrel, and the two ends of the spring are respectively abutted with the tapered block and the end of the first cylinder, The feeding and lifting assembly includes a pressurizing pipe, a lifting cylinder and a lifting piston, the pressurizing pipe penetrates through the lifting cylinder and is slidably matched with the two ends of the lifting cylinder, the lifting piston is fixedly sleeved on the pressurizing pipe, the lifting piston is slidably arranged in the lifting cylinder, and two lifting oil ports which are communicated with the inside of the lifting cylinder are formed in the two ends of the lifting cylinder; The supporting assembly includes a supporting plate and a supporting rod, the supporting plate is detachably connected with one end of the supporting rod, and a through inner threaded oil injection hole is formed in the supporting plate; One end of the pressurizing pipe is threadedly connected with the inner threaded oil injection hole, and the other end of the pressurizing pipe is threadedly connected with the end of the housing away from the second cylinder.

2. A pressure-containing valve changing device without releasing the wellhead gas tree according to claim 1, characterized in that, The hollow butt flange is threadedly sleeved on one end of the lifting cylinder barrel close to the plugging assembly, and the other end of the butt flange is matched with the valve to be replaced.

3. A pressure-containing valve changing device without releasing the wellhead gas tree according to claim 1, characterized in that, The support rod is bolted to a large four-way valve seat at an end of the support rod away from the support plate.

4. The pressure-containing valve-replacing device without releasing of the gas tree at the wellhead according to claim 1 or 3, characterized in that, The support rod is provided in a plurality of numbers and is circumferentially distributed.

5. The wellhead Christmas tree non-freeing pressure changing valve device according to claim 1, characterized in that, Sealing rings are arranged between the mandrel and the first core hole, between the mandrel and the second core hole, between the outer wall of the first cylinder barrel and the end of the second cylinder barrel away from the guide shoe, between the piston and the inner wall of the second cylinder barrel, between the lifting piston and the inner wall of the lifting cylinder barrel, and between the pressurizing pipe and the two ends of the lifting cylinder barrel.

6. A pressure-containing valve changing device without releasing the wellhead gas tree according to claim 1, characterized in that, The rubber tube assembly comprises a plurality of rubber tubes, and adjacent two rubber tubes are provided with a spacer ring.

7. A pressure-containing valve changing device without releasing the wellhead gas tree according to claim 1, characterized in that, The extraction pipe is threadedly matched with one end of the shell away from the second cylinder barrel, and the poking rod is movably arranged in the extraction pipe, and one end of the poking rod is matched with the end of the mandrel away from the first cylinder barrel.

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