Quick-change backpack-type safety valve double-pipe Christmas tree

Abstract

This invention relates to the field of dual-tube wellhead technology and provides a dual-tube wellhead with a backpack-style safety valve that allows for quick replacement. The system includes: a four-way pipe with a lower four-way pipe fixedly connected to its bottom; production wing pipes and venting wing pipes at both ends of the four-way pipe; a main safety valve unit at the top of the four-way pipe; a quick-integration unit on the outer surface of the four-way pipe; and a spare safety valve unit mounted on the quick-integration unit. Addressing the problems of existing dual-tube wellhead safety valve maintenance requiring complete well shutdown, reliance on hoisting equipment, and cumbersome valve core disassembly, this invention integrates an upper disassembly mechanism into the main safety valve unit, allowing the upper valve body to be moved laterally and rotated to the working side. The valve core adopts a magnetic layered structure, enabling quick disassembly and maintenance without fasteners. A horizontal sliding rail quick-integration unit enables universal and rapid docking between the spare and main safety valves.

Description

Technical Field

[0001] This invention relates to the field of dual-tube wellhead technology, and in particular to a dual-tube wellhead with a quick-change backpack-type safety valve. Background Technology

[0002] As a core safety shut-off component of the wellhead system, the surface safety valve is subjected to long-term corrosion from high temperature, high pressure, and sulfur-containing media. Valve cores, seals, and other vulnerable parts require regular inspection and replacement. In existing technologies, safety valves in dual-tube production trees mostly employ an integral flange fixed connection structure. Overhauling internal components requires a complete well shutdown, disassembling dozens of connecting bolts, and using large hoisting equipment to remove the valve body—a cumbersome and time-consuming process. Furthermore, the internal valve core assembly generally uses rigid bolt connections, requiring the removal of numerous fasteners to replace seals, further extending downtime.

[0003] Existing patent document CN2023209295792 provides a modular wellhead production tree that is easy to disassemble. It uses a slot-type connection to achieve the disassembly of the production tree module, but it only addresses the overall structure of the production tree and does not have a design for the rapid lateral removal of the local structure of the safety valve. It still requires hoisting equipment and cannot be operated by a single person. Summary of the Invention

[0004] The purpose of this invention is to solve the problem that existing dual-tube wellhead safety valves mostly adopt an integral flange fixed connection structure, which requires a complete well shutdown, disassembly of dozens of connecting bolts, and removal of the valve body with the help of large hoisting equipment when inspecting internal components. This is a cumbersome and time-consuming operation process. The invention provides a dual-tube wellhead with a backpack-type safety valve that can be replaced quickly.

[0005] The technical solution adopted by this invention to solve its technical problem is: a dual-tube wellhead with a quick-change backpack-type safety valve, comprising: a four-way pipe, the bottom of which is fixedly connected to a four-way lower pipe, the bottom of which is connected to the tubing head, and production wing pipes and blowout wing pipes respectively provided at both ends of the four-way pipe, and further comprising: The main safety valve unit is located at the top of the four-way pipe, the quick integration unit is located on the outer surface of the four-way pipe, and the spare safety valve unit is installed on the quick integration unit; The main safety valve unit includes a lower valve body, an oil outlet is provided on the outer surface of the lower valve body, an upper valve body is provided on the top of the lower valve body, an upper disassembly mechanism is also provided on the outer surface of the lower valve body, an opening and closing control component is provided inside the upper valve body, a valve seat is fixedly connected inside the lower valve body, and the upper disassembly mechanism assists in separating the upper valve body and the internal opening and closing control component from the lower valve body. The upper disassembly mechanism includes a first guide rod, one end of which is fixedly connected to an end block, a first movable block is slidably connected to the outer surface of the first guide rod, a first handle is fixedly connected to both sides of the first movable block, a first support rod is fixedly connected to the top of the first movable block, a support block is rotatably connected to the top of the first support rod, and a second handle is fixedly connected to the outer surface of the support block.

[0006] Preferably, the lower valve body is fixedly connected to the top of the four-way pipe, the end of the first guide rod away from the end block is fixedly connected to the outer surface of the lower valve body, the end of the support block away from the first support rod is fixedly connected to the outer surface of the upper valve body, and the upper valve body and the lower valve body are connected by inserting a clamping plate and installing bolts.

[0007] Preferably, the opening and closing control component includes a knob, a second support rod is fixedly connected to the bottom of the knob, the bottom of the second support rod is provided with a thread, a screw block that is threadedly connected to the thread is fixedly connected inside the upper valve body, a first support plate is rotatably connected to the bottom of the thread, a telescopic spring is fixedly connected to the bottom of the first support plate, and a valve core assembly is fixedly connected to the bottom of the telescopic spring.

[0008] Preferably, the knob is located on the top of the upper valve body and is fixed by contact with the interior of the upper valve body through a second support rod and threads.

[0009] Preferably, the valve core assembly includes a first magnetic plate, a second magnetic plate is magnetically connected to the bottom of the first magnetic plate, a first embedded cone is fixedly connected to the bottom center of the second magnetic plate, and first inner columns are symmetrically arranged at the bottom of the second magnetic plate; The valve core assembly also includes a backflush plate, the backflush plate having a first inner groove and a second inner groove respectively, a top conical groove fixedly connected to the top of the backflush plate, a bottom conical groove in the middle of the backflush plate, and a lower cover end at the bottom of the backflush plate. The valve core assembly also includes a valve disc, a second embedded cone is fixedly connected to the top center of the valve disc, and a second inner post is symmetrically fixed to the top of the valve disc.

[0010] Preferably, the top of the first magnetic plate is fixedly connected to the bottom of the telescopic spring, the first embedded cone and the top cone groove are coaxially and conically centered and inserted into each other, and the first inner column moves up and down along the first inner groove.

[0011] Preferably, the second embedded cone and the bottom cone groove are coaxially and conically centered and inserted into each other, the second inner column moves up and down along the second inner groove, and the lower cover end is sealed and fitted with the top of the valve seat.

[0012] Preferably, the backup safety valve unit has the same basic structure as the main safety valve unit, and a first fixing plate and a second fixing plate are fixedly connected to the outer side of the lower valve body of the backup safety valve unit. The first fixing plate and the second fixing plate are used to cooperate with the quick integration unit for positioning.

[0013] Preferably, the rapid integration unit includes a second guide rod, one end of which is fixedly connected to an end plate, a second moving block is slidably connected to the outer surface of the second guide rod, a first support frame is fixedly connected to the top of the second moving block, a first positioning post is fixedly connected to the top of the first support frame, a third guide rod is also fixedly connected to the top of the second moving block, a second support frame is slidably connected to the outer surface of the third guide rod, a second positioning post is fixedly connected to the top of the second support frame, a third support rod is fixedly connected to the top of the end plate, and a sealing gasket is fixedly connected to the top of the third support rod.

[0014] Preferably, the end of the second guide rod away from the end plate is fixedly connected to the outer surface of the four-way pipe, and the first fixing plate and the second fixing plate are disposed on the lower valve body of the spare safety valve unit; The first positioning post is inserted into and positioned in conjunction with the first fixing plate, the second positioning post is inserted into and positioned in conjunction with the second fixing plate, and the top of the sealing gasket is in contact with the bottom of the lower valve body of the standby safety valve unit.

[0015] The beneficial effects of this invention are as follows: By setting an upper disassembly mechanism consisting of a first guide rod, a first moving block, and a rotatable support block on the outside of the upper valve body, during maintenance, the valve core assembly is first lifted into the internal cavity of the upper valve body by the opening and closing control component. After removing the clamping plates and connecting bolts of the upper and lower valve bodies, the first moving block can be pulled laterally to completely separate the upper valve body from the lower valve body. The support block is then rotated to rotate the upper valve body to the working side that is easy to operate. The entire upper valve body can be removed without the need for large hoisting equipment.

[0016] By using a layered valve core assembly with the first and second magnetic plates magnetically connected, maintenance can be performed without disassembling any fasteners. The valve disc, backflushing plate, and other vulnerable parts can be disassembled one by one by simply pulling downwards, enabling a comprehensive inspection and replacement of all sealing surfaces. This significantly shortens the maintenance time of internal components and reduces the labor intensity of on-site workers.

[0017] (3) By setting a quick integration unit consisting of a second guide rod, a sliding second moving block and a double positioning column on the outside of the four-way pipe, and cooperating with the first fixing plate and the second fixing plate on the outside of the valve body of the backup safety valve unit, the backup safety valve can be quickly positioned, loaded and precisely coaxially docked without the need for repeated manual centering adjustments. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the external structure of the present invention.

[0019] Figure 2 This is a partial structural diagram of the present invention.

[0020] Figure 3 This is a schematic diagram of the main safety valve unit of the present invention.

[0021] Figure 4 This is a cross-sectional view of the main safety valve unit of the present invention.

[0022] Figure 5 This is a schematic diagram of the quick disassembly mechanism of the present invention.

[0023] Figure 6 This is a schematic diagram of the opening and closing control component of the present invention.

[0024] Figure 7 This is a cross-sectional view of the valve core assembly of the present invention.

[0025] Figure 8 This is a partial structural schematic diagram of the valve core assembly of the present invention.

[0026] Figure 9 This is a schematic diagram of the structure of the rapid integration unit of the present invention.

[0027] Figure 10 This is a top view of the structure of the rapid integration unit of the present invention.

[0028] In the diagram: 1. Lower four-way pipe; 2. Four-way pipe; 3. Production wing pipe; 4. Exhaust wing pipe; 5. Main safety valve unit; 6. Quick integration unit; 7. Backup safety valve unit; 8. Main valve; 51. Lower valve body; 52. Oil outlet; 53. Upper valve body; 54. Quick disassembly mechanism; 55. Valve seat; 56. Opening and closing control assembly; 57. Mounting plate; 541. First guide rod; 542. End block; 543. First moving block; 544. First handle; 545. First support rod; 546. Support block; 547. Second handle; 561. Knob; 562. Second support rod; 563. Thread; 564. Thread block; 565. First support plate; 566. Telescopic spring; 567. Valve Core assembly; 5671, First magnetic plate; 5672, Second magnetic plate; 5673, First embedded cone; 5674, First inner post; 5675, Backflush plate; 5676, First inner groove; 5677, Second inner groove; 5678, Valve disc; 5679, Second embedded cone; 56710, Second inner post; 56711, Lower cover end; 56712, Top cone groove; 56713, Bottom cone groove; 61, Second guide rod; 62, End plate; 63, Second moving block; 64, First support frame; 65, First positioning post; 66, Third guide rod; 67, Second support frame; 68, Second positioning post; 69, Third support rod; 610, Sealing gasket; 71, First fixing plate; 72, Second fixing plate. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the further embodiments described herein are merely illustrative and not intended to limit the invention.

[0030] like Figures 1-2 As shown, a dual-tube wellhead with a quick-change backpack-type safety valve includes: a four-way pipe 2, a four-way lower pipe 1 fixedly connected to the bottom of the four-way pipe 2, a main valve 8 installed on the outer surface of the four-way lower pipe 1, and a sealed connection between the bottom of the four-way lower pipe 1 and the integrated tubing head of the dual tubing hanger. Two independent and completely sealed vertical main production channels are prefabricated inside the four-way pipe 2, corresponding to two independent downhole tubing strings respectively. Production wing pipes 3 and blowout wing pipes 4 are respectively installed at both ends of the four-way pipe 2. It also includes: The main safety valve unit 5 is located at the top of the four-way pipe 2, the quick integration unit 6 is located on the outer surface of the four-way pipe 2, and the spare safety valve unit 7 is installed on the quick integration unit 6; During operation, oil and gas will enter the main safety valve unit 5 along the four-way lower pipe 1 and eventually be output to the ground. When the main safety valve unit 5 needs to be inspected, the valve body of the main safety valve unit 5 can be quickly separated for easy inspection. When the entire main safety valve unit 5 needs to be replaced for inspection, the overall installation assists in guiding the movement of the backup safety valve unit 7 and connecting it with the four-way pipe 2.

[0031] like Figures 3-4 As shown, the main safety valve unit 5 includes a lower valve body 51, an oil outlet 52 is provided on the outer surface of the lower valve body 51, an upper valve body 53 is provided on the top of the lower valve body 51, an upper disassembly mechanism is also provided on the outer surface of the lower valve body 51, an opening and closing control component 56 is provided inside the upper valve body 53, a valve seat 55 is fixedly connected inside the lower valve body 51, and the upper disassembly mechanism assists in separating the upper valve body 53 and the opening and closing control component 56 inside from the lower valve body 51. Under normal production conditions, the opening and closing control component 56 inside the main safety valve unit 5 remains fully open. Downhole oil and gas rise along the four-way downpipe 1 into the lower valve body 51, pass through the valve seat 55 flow channel into the upper valve body 53, and finally output from the oil outlet 52 on the side of the lower valve body 51 to the surface gathering pipeline. When there is overpressure at the wellhead, pipeline leakage, or when an emergency shutdown command is triggered, the opening and closing control component 56 drives the valve core to move downward quickly, forming a hard seal with the valve seat 55 inside the lower valve body 51, completely cutting off the fluid passage of the corresponding production channel and achieving safety isolation. After the fault is cleared, the opening and closing control component 56 drives the valve core to reset upward, the flow channel is reopened, and normal production is restored.

[0032] like Figure 5 As shown, the upper disassembly mechanism includes a first guide rod 541, one end of which is fixedly connected to an end block 542. A first moving block 543 is slidably connected to the outer surface of the first guide rod 541. A first handle 544 is fixedly connected to both sides of the first moving block 543. A first support rod 545 is fixedly connected to the top of the first moving block 543. A support block 546 is rotatably connected to the top of the first support rod 545. A second handle 547 is fixedly connected to the outer surface of the support block 546.

[0033] When overhauling the internal components of the main safety valve unit 5, it is necessary to first shut off the main valve 8 and release the pressure in the channel to a safe state. Then, remove the clamping plate 57 and connecting bolts between the upper valve body 53 and the lower valve body 51. After that, move the valve core assembly 567 into the upper valve body 53 by using the opening and closing control assembly 56, so that the valve core assembly 567 is separated from the valve seat 55 and the lower valve body 51. Then, grasp the first handle 544 and move it laterally along the first guide rod 541. The first support rod 545 drives the support block 546 and the upper valve body 53 fixed on the support block 546 to move laterally as a whole, so that the connecting surface between the upper valve body 53 and the lower valve body 51 is completely separated. Then, grasp the second handle 547 and rotate the support block 546 to rotate the upper valve body 53 and the internal opening and closing control assembly 56 to the working side that is easy to operate. Then, the opening and closing control assembly 56 can be overhauled or replaced.

[0034] The lower valve body 51 is fixedly connected to the top of the four-way pipe 2. The end of the first guide rod 541 away from the end block 542 is fixedly connected to the outer surface of the lower valve body 51. The end of the support block 546 away from the first support rod 545 is fixedly connected to the outer surface of the upper valve body 53. The upper valve body 53 and the lower valve body 51 are connected by inserting a clamping plate 57 and installing bolts.

[0035] like Figure 6 As shown, the opening and closing control assembly 56 includes a knob 561, a second support rod 562 fixedly connected to the bottom of the knob 561, a thread 563 provided at the bottom of the second support rod 562, a screw block 564 fixedly connected to the inside of the upper valve body 53 and threadedly connected to the thread 563, a first support plate 565 rotatably connected to the bottom of the thread 563, a telescopic spring 566 fixedly connected to the bottom of the first support plate 565, and a valve core assembly 567 fixedly connected to the bottom of the telescopic spring 566.

[0036] During normal production, rotating the top knob 561 clockwise causes the second support rod 562 and thread 563 to rotate downwards along the screw block 564, pulling the first support plate 565 downwards simultaneously, so that the telescopic spring 566 is in a pre-compressed state. At this time, the spring force will press the valve core assembly 567, but the oil and gas pressure flowing at this time is greater than the spring force of the telescopic spring 566, so the valve core assembly 567 will be pushed away from the valve seat 55, and the oil and gas will flow out through the gap between the valve core assembly 567 and the valve seat 55, ensuring that the production flow channel is unobstructed. Conversely, by continuing to rotate the top knob 561, the first support plate 565 and the telescopic spring 566 are further moved downwards, causing the compression of the telescopic spring 566 to continuously increase. The spring preload increases linearly. When the spring force increases to a level greater than the pressure of the flowing oil and gas, the valve core assembly 567 is no longer pushed up by the fluid, but is tightly pressed against the sealing surface of the valve seat 55 by the telescopic spring 566. The flow gap between the valve core assembly 567 and the valve seat 55 is completely closed, completely cutting off the flow path of oil and gas, and realizing the reliable manual shut-off of the production channel.

[0037] Meanwhile, when disassembling the upper valve body 53, the top knob 561 needs to be rotated counterclockwise to move the first support plate 565, the telescopic spring 566, and the overall valve core assembly 567 upward, so as not to obstruct the lateral movement of the overall upper valve body 53.

[0038] The knob 561 is located on the top of the upper valve body 53 and is fixed by contact with the inside of the upper valve body 53 through the second support rod 562 and the thread 563.

[0039] like Figures 7-8 As shown, the valve core assembly 567 includes a first magnetic plate 5671, a second magnetic plate 5672 magnetically connected to the bottom of the first magnetic plate 5671, a first embedded cone 5673 fixedly connected to the bottom center of the second magnetic plate 5672, and a first inner post 5674 symmetrically arranged at the bottom of the second magnetic plate 5672. Both the first magnetic plate 5671 and the second magnetic plate 5672 are made of samarium cobalt permanent magnet material, which is resistant to high temperature and can maintain stable magnetic attraction performance in the high-temperature oil and gas environment at the wellhead, avoiding irreversible demagnetization failure.

[0040] The valve core assembly 567 also includes a backflush plate 5675. The backflush plate 5675 has a first inner groove 5676 and a second inner groove 5677 respectively. The top of the backflush plate 5675 is fixedly connected to a top cone groove 56712, the middle of the backflush plate 5675 is provided with a bottom cone groove 56713, and the bottom of the backflush plate 5675 is provided with a lower cover end 56711. The valve core assembly 567 also includes a valve disc 5678, a second embedded cone 5679 fixedly connected to the top center of the valve disc 5678, and a second inner post 56710 symmetrically fixed to the top of the valve disc 5678.

[0041] During normal production flow, the first magnetic plate 5671 moves down synchronously with the telescopic spring 566 and remains in a pre-compressed state. Through magnetic attraction, it drives the second magnetic plate 5672, the backflush plate 5675, and the valve disc 5678 to form a rigid synchronous whole. The first embedded cone 5673 and the top cone groove 56712, and the second embedded cone 5679 and the bottom cone groove 56713 respectively achieve coaxial centering between the components. The first inner column 5674 slides along the first inner groove 5676, and the second inner column 56710 slides along the second inner groove 5677 axially to restrict relative rotation, ensuring that the valve core is not tilted. At this time, the fluid pressure is greater than the spring preload, and the entire valve core assembly 567 is pushed upward by the fluid. The lower cover end 56711 at the bottom of the valve disc 5678 separates from the valve seat 55 to form an annular flow gap, and the oil and gas are smoothly output through the flow channel.

[0042] When manually shut off, the compression of the telescopic spring 566 increases, and the spring force pushes the first magnetic plate 5671, the second magnetic plate 5672, the recoil plate 5675 and the valve disc 5678 to move down synchronously. Under the precise centering action of the guide structure, the lower cover end 56711 of the valve disc 5678 is evenly fitted with the top sealing surface of the valve seat 55 to form a reliable hard seal and completely cut off the fluid passage.

[0043] During maintenance and disassembly, the entire valve core assembly 567 is lifted along with the opening and closing control assembly 56 into the internal cavity of the upper valve body 53, completely separating from the lower valve body 51 and valve seat 55, without hindering the lateral movement of the upper valve body 53. When repairing the vulnerable parts of the valve core separately, there is no need to remove any fasteners. Simply pull down the valve disc 5678 to separate the valve disc 5678, the backwash plate 5675, and the second magnetic plate 5672 in sequence, quickly check the wear of the sealing surface or replace the seals. During reset, aligning the corresponding embedded cone and guide post and inserting them will automatically complete the coaxial centering assembly.

[0044] Meanwhile, when inspecting the valve disc 5678, the backflush disc 5675 and the second magnetic plate 5672, the three can be pulled apart so that all positions of the three can be detected.

[0045] The top of the first magnetic plate 5671 is fixedly connected to the bottom of the telescopic spring 566. The first embedded cone 5673 and the top cone groove 56712 are coaxially and conically centered and inserted into each other. The first inner column 5674 moves up and down along the first inner groove 5676.

[0046] The second embedded cone 5679 and the bottom cone groove 56713 are coaxially and conically centered and inserted into each other. The second inner column 56710 moves up and down along the second inner groove 5677. The lower cover end 56711 is sealed and fitted with the top of the valve seat 55.

[0047] The backup safety valve unit 7 has the same basic structure as the main safety valve unit 5, and the lower valve body 51 of the backup safety valve unit 7 is fixedly connected to a first fixing plate 71 and a second fixing plate 72. The first fixing plate 71 and the second fixing plate 72 are used to cooperate with the quick integration unit 6 for positioning.

[0048] like Figures 9-10 As shown, the quick integration unit 6 includes a second guide rod 61, one end of which is fixedly connected to an end plate 62. A second moving block 63 is slidably connected to the outer surface of the second guide rod 61. A first support frame 64 is fixedly connected to the top of the second moving block 63. A first positioning post 65 is fixedly connected to the top of the first support frame 64. A third guide rod 66 is also fixedly connected to the top of the second moving block 63. A second support frame 67 is slidably connected to the outer surface of the third guide rod 66. A second positioning post 68 is fixedly connected to the top of the second support frame 67. A third support rod 69 is fixedly connected to the top of the end plate 62. A sealing gasket 610 is fixedly connected to the top of the third support rod 69.

[0049] The end of the second guide rod 61 away from the end plate 62 is fixedly connected to the outer surface of the four-way pipe 2. The first fixing plate 71 and the second fixing plate 72 are set on the lower valve body 51 on the spare safety valve unit 7. The first positioning post 65 is inserted and positioned with the first fixing plate 71, and the second positioning post 68 is inserted and positioned with the second fixing plate 72. The top of the sealing gasket 610 is in contact with the bottom of the lower valve body 51 of the backup safety valve unit 7, so that external impurities will not enter its interior from the bottom of the backup safety valve unit 7.

[0050] The backup safety valve unit 7 is initially fixed by the first positioning post 65 docking with the first fixing plate 71. Then, the second support frame 67 is pulled to allow the second positioning post 68 to enter the second fixing plate 72 for complete fixation. When the main safety valve unit 5 malfunctions and needs to be replaced as a whole, the main valve 8 is closed first, and then the second moving block 63 is pulled to move the backup safety valve unit 7 to the docking point of the four-way pipe 2 for fixing and sealing.

[0051] After the faulty main safety valve unit 5 is repaired, it can be reinstalled back in its original position following the reverse process described above, and the backup safety valve unit 7 can be closed and disassembled. Alternatively, the backup safety valve unit 7 can be kept on the quick integration unit 6 as an online backup device, which can be directly switched to when the safety valve fails again, further shortening the emergency response time.

[0052] The working principle of this invention is as follows: During normal production, rotating the top knob 561 of the main safety valve unit 5 clockwise causes the thread 563 to rotate downwards, compressing the telescopic spring 566. This makes the spring preload less than the downhole oil and gas pressure, causing the oil and gas to lift the valve core assembly 567 to form a flow gap. The oil and gas then enter the lower valve body 51 through the four-way lower pipe 1, pass through the flow channel of the valve seat 55, and enter the upper valve body 53. Finally, the oil is delivered to the surface gathering pipeline from the side outlet nozzle 52. When manual shut-off is required, continue to rotate the knob 561 clockwise to increase the spring compression, making the spring preload greater than the oil and gas pressure. The valve core assembly 567 is pressed against the valve seat 55, cutting off the fluid passage. When there is overpressure at the wellhead, the oil and gas can open the valve core to achieve automatic pressure relief protection. When inspecting the vulnerable parts inside the main safety valve, first close the main valve 8 of the four-way lower pipe 1 and depressurize it. Remove the connecting bolts of the upper and lower valve bodies 51. Rotate the knob 561 counterclockwise to lift the valve core assembly 567 into the upper valve body 53. The upper valve body 53 is moved out laterally and rotated to the working side by the upper disassembly mechanism. The valve disc 5678 and the backflush plate 5675 can be quickly disassembled for inspection and replacement using the magnetic layered structure of the valve core assembly 567. When the main safety valve unit 5 fails, the backup safety valve unit 7 is fixed on the quick integration unit 6 by inserting the first and second positioning pins 68 with the corresponding fixing plates. The second moving block 63 is pushed to slide along the second guide rod 61 toward the four-way pipe 2, so that the backup safety valve is connected to the four-way pipe 2 and sealed by the sealing gasket 610. After switching the production channel, the faulty main safety valve can be removed.

[0053] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the term "fixed connection" should be interpreted broadly. For example, it can refer to a bolted connection, a welded connection, or an integral connection; it can refer to a mechanical connection or an electrical connection; it can refer to a direct connection or an indirect connection through an intermediate medium; it can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0054] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A dual-tube wellhead with a quick-change backpack-type safety valve, comprising: A four-way pipe, wherein a four-way lower pipe is fixedly connected to the bottom of the four-way pipe, and a production wing pipe and a discharge wing pipe are respectively provided at both ends of the four-way pipe, characterized in that it further includes: The main safety valve unit is located at the top of the four-way pipe, the quick integration unit is located on the outer surface of the four-way pipe, and the spare safety valve unit is installed on the quick integration unit; The main safety valve unit includes a lower valve body, an oil outlet is provided on the outer surface of the lower valve body, an upper valve body is provided on the top of the lower valve body, an upper disassembly mechanism is also provided on the outer surface of the lower valve body, an opening and closing control component is provided inside the upper valve body, a valve seat is fixedly connected inside the lower valve body, and the upper disassembly mechanism assists in separating the upper valve body and the internal opening and closing control component from the lower valve body. The upper disassembly mechanism includes a first guide rod, an end block fixedly connected to one end of the first guide rod, a first moving block slidably connected to the outer surface of the first guide rod, a first handle fixedly connected to both sides of the first moving block, a first support rod fixedly connected to the top of the first moving block, a support block rotatably connected to the top of the first support rod, and a second handle fixedly connected to the outer surface of the support block. The backup safety valve unit has the same basic structure as the main safety valve unit, and a first fixing plate and a second fixing plate are fixedly connected to the outer side of the lower valve body of the backup safety valve unit. The first fixing plate and the second fixing plate are used to cooperate with the quick integration unit for positioning. The rapid integration unit includes a second guide rod, one end of which is fixedly connected to an end plate. A second movable block is slidably connected to the outer surface of the second guide rod. A first support frame is fixedly connected to the top of the second movable block. A first positioning post is fixedly connected to the top of the first support frame. A third guide rod is also fixedly connected to the top of the second movable block. A second support frame is slidably connected to the outer surface of the third guide rod. A second positioning post is fixedly connected to the top of the second support frame. A third support rod is fixedly connected to the top of the end plate. A sealing gasket is fixedly connected to the top of the third support rod.

2. The dual-tube wellhead of a quick-change backpack-type safety valve according to claim 1, characterized in that: The lower valve body is fixedly connected to the top of the four-way pipe. The end of the first guide rod away from the end block is fixedly connected to the outer surface of the lower valve body. The end of the support block away from the first support rod is fixedly connected to the outer surface of the upper valve body. The upper valve body and the lower valve body are connected by inserting a clamping plate and installing bolts.

3. The dual-tube wellhead of a quick-change backpack-type safety valve according to claim 1, characterized in that: The opening and closing control component includes a knob, a second support rod is fixedly connected to the bottom of the knob, the bottom of the second support rod is provided with a thread, a screw block that is threadedly connected to the thread is fixedly connected inside the upper valve body, a first support plate is rotatably connected to the bottom of the thread, a telescopic spring is fixedly connected to the bottom of the first support plate, and a valve core assembly is fixedly connected to the bottom of the telescopic spring.

4. The dual-tube wellhead of a quick-change backpack-type safety valve according to claim 3, characterized in that: The knob is located on the top of the upper valve body and is fixed by contact with the interior of the upper valve body through a second support rod and threads.

5. A dual-tube wellhead for quick-change backpack-type safety valves according to claim 3, characterized in that: The valve core assembly includes a first magnetic plate, a second magnetic plate magnetically connected to the bottom of the first magnetic plate, a first embedded cone fixedly connected to the bottom center of the second magnetic plate, and first inner columns symmetrically arranged at the bottom of the second magnetic plate. The valve core assembly also includes a backflush plate, the backflush plate having a first inner groove and a second inner groove respectively, a top conical groove fixedly connected to the top of the backflush plate, a bottom conical groove in the middle of the backflush plate, and a lower cover end at the bottom of the backflush plate. The valve core assembly also includes a valve disc, a second embedded cone is fixedly connected to the top center of the valve disc, and a second inner post is symmetrically fixed to the top of the valve disc.

6. The dual-tube wellhead of a quick-change backpack-type safety valve according to claim 5, characterized in that: The top of the first magnetic plate is fixedly connected to the bottom of the telescopic spring, the first embedded cone and the top cone groove are coaxially and conically centered and inserted into each other, and the first inner column moves up and down along the first inner groove.

7. A dual-tube wellhead for quick-change backpack-type safety valves according to claim 5, characterized in that: The second embedded cone and the bottom cone groove are coaxially and conically centered and inserted into each other. The second inner column moves up and down along the second inner groove. The lower cover end is sealed and fitted to the top of the valve seat.

8. A dual-tube wellhead for quick-change backpack-type safety valves according to claim 1, characterized in that: The end of the second guide rod away from the end plate is fixedly connected to the outer surface of the four-way pipe. The first fixing plate and the second fixing plate are set on the lower valve body of the spare safety valve unit. The first positioning post is inserted into and positioned in conjunction with the first fixing plate, the second positioning post is inserted into and positioned in conjunction with the second fixing plate, and the top of the sealing gasket is in contact with the bottom of the lower valve body of the standby safety valve unit.

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