Wellhead gas production tree non-releasing under-pressure valve replacing device

Abstract

The invention relates to the technical field of Christmas tree valve replacement maintenance, and discloses a wellhead Christmas tree non-releasing under-pressure valve replacement device which comprises a blocking assembly, a feeding lifting assembly and a supporting assembly. The blocking assembly comprises a shell, a limiting sleeve, a second cylinder barrel, a rubber barrel assembly, a guiding shoe, a mandrel, a spring, a first cylinder barrel and a piston which are coaxially arranged; the lifting assembly comprises a pressurizing pipe, a lifting cylinder barrel and a lifting piston which are coaxially arranged with the blocking assembly, the supporting assembly comprises a supporting plate and a supporting rod, when the device is used, the supporting assembly is used for being connected with a valve seat to form counter-force supporting, and the lifting assembly can be used for pressurizing the blocking assembly and facilitating disassembly and assembly of a valve; when the plugging assembly is pressurized, the rubber sleeve assembly is axially compressed and radially expanded, under-pressure valve replacement is achieved through expansion sealing of the rubber sleeve assembly and the inner wall of a pipeline, after pressurization is stopped, the pressure maintaining effect can be achieved under the action of the elastic force of the spring and the rubber sleeve assembly, the reliability of sealing plugging is kept, and after valve replacement is completed, the mandrel can be directly jacked to relieve pressure and unblock.

Description

Technical Field

[0001] The invention relates to the technical field of valve replacement and maintenance of gas production trees, and in particular to a pressure-controlled valve replacement device for a wellhead gas production tree. Background Art

[0002] The gas tree refers to the general term for the part installed above the pipe head of the wellhead device. It is mainly composed of the wellhead four-way and the main control valve (main gate, pipeline gate, needle valve, pressure measuring gate, casing gate, etc.). It is the main device for opening and closing wells, adjusting pressure, measuring pressure with a pressure gauge, and measuring 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 once installed, so it is extremely difficult to repair and replace the main control valve. The traditional replacement method is to first use well killing fluid to kill the construction well, and then replace the wellhead main control valve after the well killing is stable. It has problems such as long construction period, many equipment, large workload, many cooperative construction units, many participants, serious environmental pollution caused by the discharge of well killing fluid, and high construction cost. At the same time, this traditional method will also cause secondary damage to the bottom of the well, especially for old wells in the middle and late stages of production. Due to the low formation energy, it is difficult to restore the original production after killing the well. Some wells may be killed and lose production capacity and become abandoned wells.

[0004] In order to overcome the defects of traditional replacement methods, technicians in this field have been committed to studying the replacement form of valve replacement under pressure. At present, we use the method of cava positioning and card point to replace valves or repair. This method is to install the cava at a fixed point on the inner wall of the pipe head at the front end of the valve to be replaced for sealing, and disconnect the valve to be replaced from the gas tree pipeline to facilitate its replacement; but in actual application, because the pipe head flow channel is corroded by acidic media due to long-term work, its inner wall is often uneven, and the selection of the card point position is difficult. After installation, the connection and sealing reliability of the cava and the inner wall are poor, and there are safety hazards in the subsequent valve replacement operation. In this method, it is also difficult to disassemble and remove the cava after the valve replacement operation. There are also various forms of devices for pipe head blocking in other fields in the prior art, but these devices are difficult to meet the requirements of reliable sealing, easy unsealing, and convenient operation when used for valve replacement under pressure on gas trees.

[0005] In addition, the main control valve and the pipe head in the gas production tree are usually connected by flanges. In the existing method, the valve replacement process is generally performed by manually disassembling and assembling the valve components. When installing a new valve component, it is necessary to lift the valve component first to align the flange before completing the installation. Since the main control valve in the gas production tree is heavy, it is extremely time-consuming and laborious to align and install the new valve component. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a pressure-changing valve device for a wellhead gas production tree without losing control, which can seal the front end pipe head of the valve to be replaced to achieve pressure-changing valves, and the entire valve changing operation process is extremely labor-saving and convenient.

[0007] The objective of the present invention is achieved through the following technical solutions: A valve changing device for a wellhead gas production tree without losing hands and under pressure, comprising a plugging component, a feeding and lifting component and a supporting component; The plugging assembly includes a coaxially arranged shell, a limit sleeve, a second cylinder, a rubber sleeve assembly, a guide shoe, a core shaft, a spring, a first cylinder, and a piston, the shell is a hollow cylindrical structure with openings at both ends, the limit sleeve is fixedly inserted into the middle of the shell, one end of the second cylinder is slidably arranged in one end of the shell, and the other end of the second cylinder is fixedly connected to the guide shoe, the rubber sleeve assembly is sleeved outside the second cylinder, and the two ends of the rubber sleeve assembly are respectively abutted against the end of the shell and the end of the guide shoe, the limit sleeve is processed with a first core hole and a first pressure transmission hole at the end away from the guide shoe, and a small diameter hole and a large diameter hole are processed in sequence along the axis to the other end in the limit sleeve, and the two ends of the first pressure transmission hole are respectively connected with the small diameter hole and the inner cavity of the end of the shell away from the second cylinder, and the connecting part of the small diameter hole and the large diameter hole forms a conical sealing platform , one end of the first cylinder is fixedly inserted into the end of the large diameter hole away from the small diameter hole and is processed with a second core hole and a second pressure transmission hole, the other end of the first cylinder is fixedly connected to the piston, and the two ends of the second pressure transmission hole are respectively connected with the large diameter hole and the inner cavity of the first cylinder, the outer wall of the first cylinder is slidably adapted to the end of the second cylinder away from the guide shoe, the piston is slidably adapted to the inner wall of the second cylinder, the piston divides the inner cavity of the second cylinder into a rod cavity and a rodless cavity, the rod cavity is arranged on the side of the piston close to the first cylinder, a third pressure transmission hole is opened on the side wall of the first cylinder, and the two ends of the third pressure transmission hole are respectively connected with the rod cavity and the inner cavity of the first cylinder, a flow channel hole is opened on the guide shoe, and the two ends of the flow channel hole are respectively connected with the rodless cavity and the side of the guide shoe away from the second cylinder, A conical block is fixedly sleeved on the core shaft, one end of the core shaft is slidably set in the first core hole, and the other end of the core shaft is slidably set in the second core hole, the conical block is set in the large diameter hole, the conical block is adapted to the conical surface sealing platform, the spring is sleeved on the core shaft, and the two ends of the spring are respectively abutted against the conical block and the end of the first cylinder; The feeding and lifting assembly comprises a coaxially arranged pressure pipe, a lifting cylinder and a lifting piston, wherein the pressure pipe runs through the lifting cylinder and is slidably fitted with two ends of the lifting cylinder, the lifting piston is fixedly sleeved on the pressure pipe, the lifting piston is slidably arranged in the lifting cylinder, and two lifting oil ports communicating with the interior of the lifting cylinder are respectively provided at two ends of the lifting cylinder; The support assembly comprises a support plate and a support rod, wherein the support plate is detachably connected to one end of the support rod, and a through internal thread oil injection hole is provided on the support plate; One end of the pressurizing tube is threadedly connected to the internal thread oil filling hole, and the other end of the pressurizing tube is threadedly connected to an end of the housing away from the second cylinder.

[0008] Furthermore, it also includes a hollow docking flange, one end of which is threadedly sleeved on one end of the lifting cylinder close to the blocking assembly, and the other end of the docking flange is adapted to the valve component to be replaced.

[0009] Furthermore, it also includes a large four-way valve seat, and one end of the support rod away from the support plate is connected to the large four-way valve seat by bolts.

[0010] Specifically, there are a plurality of support rods, and the plurality of support rods are evenly distributed around the circumference.

[0011] Specifically, sealing rings are provided between the core shaft and the first core hole, between the core shaft 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 pressure pipe and both ends of the lifting cylinder.

[0012] Specifically, the rubber cylinder assembly includes a plurality of rubber cylinders, and the plurality of rubber cylinders are sequentially sleeved outside the second cylinder, and a spacer ring is provided between two adjacent rubber cylinders.

[0013] Furthermore, it also includes a removal tube and a poke rod, one end of the removal tube is threadedly adapted to the end of the shell away from the second cylinder, the poke rod is movably arranged in the removal tube, and one end of the poke rod is adapted to the end of the core shaft away from the first cylinder.

[0014] The beneficial effects of the present invention are: The pressure-changing valve device for the wellhead gas tree can seal the front end pipe head of the valve to be replaced to achieve pressure-changing valves. The entire valve changing operation process is extremely labor-saving and convenient.

[0015] The objective of the present invention is achieved through the following technical solutions: The wellhead gas production tree non-dropping pressure valve changing device includes a plugging assembly, a feeding and lifting assembly, and a supporting assembly. The plugging assembly includes a coaxially arranged housing, a limiting sleeve, a second cylinder, a rubber sleeve assembly, a guide shoe, a core shaft, a spring, a first cylinder, and a piston. The limiting sleeve is fixedly inserted into the middle of the housing, one end of the second cylinder is slidably arranged in one end of the housing, and the other end of the second cylinder is fixedly connected to the guide shoe. The rubber sleeve assembly is sleeved outside the second cylinder, and the two ends of the rubber sleeve assembly are respectively abutted against the end of the housing and the end of the guide shoe; one end of the first cylinder is fixedly inserted into one end of the limiting sleeve, and the barrel of the first cylinder is slidably inserted into the second cylinder. One end of the first cylinder is fixedly connected with a piston, and the other end of the first cylinder is slidably arranged in the second cylinder; the core shaft is slidably arranged in the limit sleeve, a conical block is sleeved on the core shaft, and a conical surface limit platform is arranged in the limit sleeve, and the spring is used to provide elastic force to press the conical block against the conical surface sealing platform; the limit sleeve is provided with a first pressure transmission hole, and the first cylinder is provided with a second pressure transmission hole and a third pressure transmission hole; the feeding and lifting assembly includes a pressure-increasing pipe, and one end of the pressure-increasing pipe is threadedly connected to the end of the shell away from the second cylinder; the support assembly includes a support plate and a support rod. When in use, the support rod is connected to the valve seat for support, and the support plate is threadedly connected to the other end of the pressure tube; when pressurized by the pressure tube, the hydraulic oil enters through the first pressure transmission hole and can push open the conical block, and then enters the rod cavity of the second cylinder through the second pressure transmission hole, the inner cavity of the first cylinder, and the third pressure transmission hole in sequence, thereby driving the second cylinder and the guide shoe to move axially, so that the rubber cartridge assembly is axially compressed and radially expanded until the rubber cartridge assembly and the inner wall of the pipeline are tightened and sealed; after the pressurization is stopped, the spring and the rubber cartridge assembly's own elastic force can maintain the pressure and maintain the reliability of the sealing and plugging, thereby realizing pressure-carrying valve replacement.

[0016] The feeding and lifting assembly also includes a lifting cylinder and a lifting piston coaxially arranged with the pressure tube. The overall structure is a hydraulic cylinder with piston rods extending from both ends. The pressure tube is similar to the piston rod. After connecting the docking flange, when replacing the valve parts, the valve parts to be replaced or the newly installed valve parts can be driven to move by hydraulic means, making the disassembly and assembly process of the valve parts more labor-saving and convenient.

[0017] A removal tube and a poke rod are also provided. After the valve component is replaced, the poke rod can be directly used to push the core shaft to achieve pressure relief and unsealing. The blocking component can be taken out as a whole by lifting the removal tube. The unsealing and removal operations are extremely convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic cross-sectional view of the overall structure of a pressure-controlled valve changing device for a wellhead gas tree according to the present invention; Figure 2 It is a schematic cross-sectional view of the structure of a plugging assembly in a pressure-changing valve device for a wellhead gas tree without losing control of the present invention; Figure 3 for Figure 2 Enlarged view of section A in the middle; Figure 4 It is a cross-sectional structural schematic diagram of a feeding and lifting assembly in a pressure-changing valve device for a wellhead gas tree without letting go of the wellhead gas tree according to the present invention; Figure 5 It is a cross-sectional structural schematic diagram of a support assembly in a pressure-changing valve device for a wellhead gas tree without letting go of the valve; Figure 6 It is a schematic cross-sectional view of the docking flange in a support assembly in a pressure-changing valve device for a wellhead gas tree without losing control of the present invention; Figure 7 It is a schematic diagram of the use state of a pressure-operated valve changing device for a wellhead gas tree without letting go of the device according to the present invention; Figure 8 for Figure 7 An enlarged schematic diagram of the connection between the feeding and lifting assembly and the supporting assembly in the use state shown; Fig. 9 for Figure 7 An enlarged schematic diagram of the connection between the feeding and lifting assembly and the blocking assembly in the use state shown In the figure, 1-large four-way valve seat, 2-valve member, 100-blocking assembly, 101-housing, 102-limiting sleeve, 103-core shaft, 104-first cylinder, 105-second cylinder, 106-piston, 107-guide shoe, 108-rubber cylinder, 109-spacer 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-conical block, 117-spring, 200-feeding 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 filling hole, 304-joint flange. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0020] like Figures 1 to 5 As shown, a pressure-changing valve device for a wellhead gas production tree without losing control comprises a plugging assembly 100, a feeding and lifting assembly 200 and a supporting assembly 300.

[0021] like Figure 2 , Figure 3 As shown, the plugging assembly 100 includes a coaxially arranged housing 101 , a limiting sleeve 102 , a second cylinder 105 , a rubber sleeve assembly, a guide shoe 107 , a core shaft 103 , a spring 117 , a first cylinder 104 , and a piston 106 .

[0022] The shell 101 is a hollow cylindrical structure with openings at both ends. The limit sleeve 102 is fixedly inserted into the middle part of the shell 101. One end of the second cylinder 105 is slidably arranged in one end of the shell 101. The other end of the second cylinder 105 is fixedly connected to the guide shoe 107. The rubber cartridge assembly is sleeved outside the second cylinder 105. The two ends of the rubber cartridge assembly are respectively abutted against the end of the shell 101 and the end of the guide shoe 107. When the second cylinder 105 slides toward the limit sleeve 102, it can drive the guide shoe 107 to slide axially, thereby causing the rubber cartridge assembly to be axially compressed and radially expanded. The limiting sleeve 102 is a hollow columnar structure with one end open. The end of the limiting sleeve 102 away from the guide shoe 107 is a closed end, and a first core hole and a first pressure transmission hole 110 are processed at this end. A small diameter hole 111 and a large diameter hole 112 are processed in sequence along the axis toward the other end in the limiting sleeve 102 to form a hollow, and an opening is formed at the other end of the large diameter hole 112. The connecting part of the small diameter hole 111 and the large diameter hole 112 is processed to form a conical sealing platform, and the two ends of the aforementioned first pressure transmission hole 110 are respectively connected to the small diameter hole 111 and the inner cavity of one end of the shell 101 away from the second cylinder 105. The first cylinder 104 is a cylindrical structure, one end of which is a closed end. This end is fixedly inserted into the end of the large diameter hole 112 away from the small diameter hole 111 and is processed with a second core hole and a second pressure transmission hole 113. The other end of the first cylinder 104 is fixedly connected to the piston 106, and the two ends of the second pressure transmission hole 113 are respectively connected to the large diameter hole 112 and the inner cavity of the first cylinder 104. The outer wall of the first cylinder 104 is slidably fitted with the end of the second cylinder 105 away from the guide shoe 107, and the piston 106 is slidably fitted with the inner wall of the second cylinder 105. The piston 106 divides the inner cavity of the second cylinder 105 into a rod cavity and a rodless cavity. 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 opened on the side wall of the first cylinder 105. The two ends of the third pressure transmission hole 114 are respectively connected to the rod cavity and the inner cavity of the first cylinder 104. A flow channel hole 115 is opened on the guide shoe 107. The two ends of the flow channel hole 115 are respectively connected to the rodless cavity and the side of the guide shoe 107 away from the second cylinder 105. A conical block 116 is fixedly sleeved on the mandrel 103, one end of the mandrel 103 is slidably set in the aforementioned first core hole, the other end of the mandrel 103 is slidably set in the aforementioned second core hole, the conical block 116 is set in the large diameter hole 112, and the conical block 116 is adapted to the aforementioned conical surface sealing platform. A spring 117 is sleeved on the mandrel 103, and the two ends of the spring 117 are respectively in contact with the conical block 116 and the end of the first cylinder 104.

[0023] like Figure 4As shown, the feeding and lifting assembly 200 includes a coaxially arranged pressure pipe 201, a lifting cylinder 202 and a lifting piston 203. The pressure pipe 201 is a hollow tubular structure. The pressure pipe 201 passes through the lifting cylinder 202 and is slidably adapted with both ends of the lifting cylinder 202. The lifting piston 203 is fixedly sleeved on the pressure pipe 201, and the lifting piston 203 is slidably arranged in the lifting cylinder 202. Two lifting oil ports 204 communicating with the interior of the lifting cylinder 202 are respectively provided at both ends of the lifting cylinder 202. The two lifting oil ports 204 are respectively connected to hydraulic pipelines. When oil is fed into one lifting oil port 204, oil can be returned from the other lifting oil port 204. When the pressure 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.

[0024] like Figure 5 As shown, the support assembly 300 includes a support plate 301 and a support rod 302 . The support plate 301 is detachably connected to one end of the support rod 302 . A through internal threaded oil injection hole 303 is formed on the support plate 302 .

[0025] During overall assembly, one end of the pressurizing tube 201 is threadedly connected to the internal thread oil filling hole 303 , and the other end of the pressurizing tube 201 is threadedly connected to an end of the housing 101 away from the second cylinder 105 .

[0026] The pressure-changing valve device for the wellhead gas tree can be used for the pressure-changing valve of the wellhead gas tree, replacing the traditional well-killing valve changing method, and effectively solving the problems of the traditional valve changing method, such as long construction period, many equipments, large workload, many cooperative construction units, many participants, serious environmental pollution caused by the discharge of well-killing fluid, and high construction cost.

[0027] by Figures 7 to 9 Taking the replacement of the valve member 2 at the top of the large four-way valve seat 1 of the wellhead as an example, the valve replacement operation can be performed according to the following steps: S1. Assemble the valve changing device for the wellhead gas production tree without losing control under pressure as described above, connect the internal threaded oil filling hole 303 of the support plate 301 to the pump oil pipeline, and connect the two lifting oil ports 204 to the oil supply pipeline.

[0028] S2. Open the valve component 2 to be replaced, extend the blocking assembly 100 through the center of the valve component 2 to the pipe head position at the front end of the valve component 2, and then fix the end of the support rod 302 in the support assembly 300 away from the support plate 301 to the large four-way valve seat 1 by bolts.

[0029] S3, pump oil into the internal threaded oil injection hole 303 to perform a pressurization operation. When pressurizing, the hydraulic oil flows into the end of the housing 101 in the plugging component 100 away from the guide shoe 107 through the pressure tube 201, and then in the plugging component 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 increases, and the pressure acts on the conical block 116 to drive the core shaft 103 to move axially downward as a whole and compress the spring 117. At this time, the conical block 116 separates from the conical surface sealing platform and a gap is generated. The hydraulic oil flows from the gap into the large diameter hole 112, and then the liquid The pressurized oil flows into the rod cavity of the second cylinder 105 through the second pressure transmission hole 113, the inner cavity of the first cylinder 104, and the third pressure transmission hole 114 in sequence. 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 hindrance. As the hydraulic oil in the rod cavity increases, the second cylinder 105 and the guide shoe 107 can be driven to move axially upward as a whole, so that the rubber cylinder assembly is axially compressed and radially expanded until the outer wall of the rubber cylinder assembly and the inner wall of the pipeline are tightened, thus completing the plugging of the front end pipeline of the valve 2 to be replaced. Since the plugging tool is plugged by the expansion of the rubber cylinder assembly, it is less affected by the unevenness of the inner wall of the pipeline during use, and can effectively solve the problem of difficult selection of the stuck point position.

[0030] S4, stop pressurizing. When pressurizing is stopped, the spring 117 rebounds and presses the conical block 116 against the conical sealing platform to form a seal. At the same time, the elastic force of the rubber cylinder assembly itself also forms an inward-moving tendency force, which causes the second cylinder 105 and the guide shoe 107 to 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 through the third pressure transmission hole 114, the inner cavity of the first cylinder 104, and the second pressure transmission hole 113 in turn, and further acts on the conical block 116 to maintain the stability of the seal there. It can be seen that after the pressurization is stopped, the plugging assembly 100 forms an automatic pressure-maintaining effect, which can effectively ensure the reliability of pipeline plugging.

[0031] S5, remove the connecting bolts of the support plate 301 in the support assembly 300 to disconnect it from the support rod 302, then disconnect the pressure pipe 201 from the housing 101, then remove the feeding and lifting assembly 200, and then replace the valve component 2. It should be noted that if the time-consuming and labor-intensive effect of manually replacing the valve component 2 is not considered, the connecting bolts of the support rod 302 and the large four-way valve seat 1 in the support assembly 300 can also be removed here, and the support assembly 300 and the feeding and lifting assembly 200 can be removed as a whole to replace the valve component 2.

[0032] S6. After the valve 2 is replaced, connect the removal assembly, remove the plugging assembly 100, and then close the valve 2 to complete the replacement operation. In specific implementation, the removal assembly includes a removal tube and a poke rod. One end of the removal tube is threadedly adapted to the end of the shell 101 away from the second cylinder 105. The poke rod is movably arranged in the removal tube, and one end of the poke rod is adapted to the end of the core shaft 103 away from the first cylinder 104. When in use, first make one end of the removal tube pass through the installed valve 2 and directly connect with the top thread of the shell 101. Then, use the poke rod to pass through the removal tube and push the core shaft 103 to separate the conical block 116 from the conical sealing platform to complete the pressure relief. Under the action of the aforementioned trend force, the rubber cylinder assembly is retracted, thereby quickly realizing the unsealing. Then, the plugging tool can be taken out as a whole by lifting the removal tube.

[0033] It should be understood that the above is only an embodiment of replacing the top valve of the wellhead large four-way valve seat. According to the above operation process, it can be applied to the replacement of various types of valve seats and valves installed in various positions of the valve seat. According to the above operation process, it can be seen that the wellhead gas tree pressure-changing device does not need to be used for the replacement of gas tree valves, and can realize pressure-changing valves. It has the advantages of reliable sealing and easy unsealing, and has a relatively simple structure and is easy to use.

[0034] Furthermore, it also includes a hollow docking flange 304, whose structure is as follows Figure 6 As shown, when in use, one end of the docking flange 304 is threadedly sleeved on one end of the lifting cylinder 202 close to the plugging assembly 100, and the other end of the docking flange 304 is connected to the flange end of the valve member 2 to be replaced. When the valve member 2 is replaced in the aforementioned step S5, during the disassembly stage of the valve member 2, the lifting cylinder 202 can be driven to move axially upward by pumping oil to one lifting oil port 204. Since the valve member 2 to be disassembled is fixedly connected to the lifting oil cylinder 202, it is convenient to separate and lift the valve member 2 from the large four-way valve seat 1; during the installation stage of the new valve member 2, the new valve member can be installed on the feeding lifting assembly 200, and after the feeding lifting assembly 200 and the supporting assembly 300 are assembled in the aforementioned form, the lifting cylinder 202 can be driven to move axially downward by pumping oil to the other lifting oil port 204 to drive the valve member 2. At this time, the hole alignment operation when the new valve member 2 is installed on the large four-way valve seat 1 can be facilitated, solving the problem of the difficulty of installing the new valve on the hole due to the heavy weight of the valve seat.

[0035] During specific implementation, there are several support rods 302 in the support assembly 300, and the several support rods 302 are evenly distributed around the circumference. When in use, the support assembly 300 as a whole presents a cage-like structure to ensure its structural strength; sealing rings are provided between the core shaft 103 and the first core hole, between the core shaft 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 two ends of the pressure tube 201 and the lifting cylinder 202 to ensure the sealing and pressure transmission effects; the rubber cylinder assembly includes several rubber cylinders 108, and the several rubber cylinders 108 are sequentially sleeved outside the second cylinder 105, and a spacer ring 109 is provided between two adjacent rubber cylinders 108, thereby overcoming the problem of unstable expansion sealing performance caused by the excessive height-to-diameter ratio of a single rubber cylinder, and decomposing it into multiple short-section rubber cylinders can better ensure the sealing reliability.

[0036] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. A pressure-controlled valve changing device for a wellhead gas tree, characterized in that: It includes a blocking component, a feeding and lifting component, and a supporting component; The plugging assembly includes a coaxially arranged housing, a limiting sleeve, a second cylinder, a rubber cylinder assembly, a guide shoe, a core shaft, a spring, a first cylinder, and a piston. The shell is a hollow cylindrical structure with two ends open, the limit sleeve is fixedly installed in the middle of the shell, one end of the second cylinder is slidably arranged in one end of the shell, the other end of the second cylinder is fixedly connected to the guide shoe, the rubber tube assembly is sleeved outside the second cylinder, and the two ends of the rubber tube assembly are respectively abutted against the end of the shell and the end of the guide shoe. The end of the limit sleeve away from the guide shoe is processed with a first core hole and a first pressure transmission hole, and the inside of the limit sleeve is processed with a small diameter hole and a large diameter hole in sequence along the axis toward the other end, and the two ends of the first pressure transmission hole are respectively connected with the small diameter hole and the inner cavity of the end of the shell away from the second cylinder, and the connection part of the small diameter hole and the large diameter hole forms a conical sealing platform, One end of the first cylinder is fixedly inserted into the end of the large diameter hole away from the small diameter hole and is processed with a second core hole and a second pressure transmission hole. The other end of the first cylinder is fixedly connected to the piston. Both ends of the second pressure transmission hole are respectively connected to the large diameter hole and the inner cavity of the first cylinder. The outer wall of the first cylinder is slidably fitted with the end of the second cylinder away from the guide shoe, the piston is slidably fitted with the inner wall of the second cylinder, the piston divides the inner cavity of the second cylinder into a rod cavity and a rodless cavity, the rod cavity is arranged on the side of the piston close to the first cylinder, a third pressure transmission hole is provided on the side wall of the first cylinder, the two ends of the third pressure transmission hole are respectively connected with the rod cavity and the inner cavity of the first cylinder, the guide shoe is provided with a flow channel hole, the two ends of the flow channel hole are respectively connected with the rodless cavity and the side of the guide shoe away from the second cylinder, A conical block is fixedly sleeved on the core shaft, one end of the core shaft is slidably disposed in the first core hole, the other end of the core shaft is slidably disposed in the second core hole, the conical block is disposed in the large diameter hole, and the conical block is adapted to the conical surface sealing platform. The spring is sleeved on the core shaft, and two ends of the spring are respectively in contact with the conical block and the end of the first cylinder; The feeding and lifting assembly comprises a coaxially arranged pressure pipe, a lifting cylinder and a lifting piston, wherein the pressure pipe runs through the lifting cylinder and is slidably fitted with two ends of the lifting cylinder, the lifting piston is fixedly sleeved on the pressure pipe, the lifting piston is slidably arranged in the lifting cylinder, and two lifting oil ports communicating with the interior of the lifting cylinder are respectively provided at two ends of the lifting cylinder; The support assembly comprises a support plate and a support rod, wherein the support plate is detachably connected to one end of the support rod, and a through internal thread oil injection hole is provided on the support plate; One end of the pressurizing tube is threadedly connected to the internal thread oil filling hole, and the other end of the pressurizing tube is threadedly connected to an end of the housing away from the second cylinder.

2. The device for changing valves under pressure at a wellhead gas tree without losing control according to claim 1, characterized in that: It also includes a hollow docking flange, one end of which is threadedly sleeved on one end of the lifting cylinder barrel close to the blocking assembly, and the other end of the docking flange is adapted to the valve component to be replaced.

3. The pressure-controlled valve changing device for a wellhead gas tree according to claim 1 is characterized in that: It also includes a large four-way valve seat, and one end of the support rod away from the support plate is connected to the large four-way valve seat by bolts.

4. A valve changing device for a wellhead gas tree without losing control under pressure according to claim 1 or 3, characterized in that: There are a plurality of support rods, and the plurality of support rods are evenly distributed around the circumference.

5. The device for changing valves under pressure at a wellhead gas tree without losing control according to claim 1, characterized in that: Sealing rings are provided between the core shaft and the first core hole, between the core shaft 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 pressure pipe and both ends of the lifting cylinder.

6. The device for changing valves under pressure at a wellhead gas tree without losing control according to claim 1, characterized in that: The rubber cylinder assembly comprises a plurality of rubber cylinders, which are sleeved on the outside of the second cylinder in sequence, and a spacer ring is arranged between two adjacent rubber cylinders.

7. The device for changing valves under pressure at a wellhead gas tree without losing control according to claim 1, characterized in that: It also includes a removal tube and a poke rod, one end of the removal tube is threadedly adapted to an end of the shell away from the second cylinder, the poke rod is movably arranged in the removal tube, and one end of the poke rod is adapted to an end of the core shaft away from the first cylinder.

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