Large bore fracturing wellhead

Abstract

The application discloses a large-passage fracturing wellhead and relates to the technical field of fracturing wellheads, which comprises a support frame, a sleeve structure is arranged on the inner side of the middle part of the support frame, flow control valve ends for controlling liquid flux are arranged on the two sides of the sleeve structure, a testing mechanism is connected between the adjacent flow control valve ends, the testing mechanism comprises a sealing port, deep ring grooves are formed on the two sides of the sealing port, a communication pipe is fixedly connected to the outer surface of the sealing port, an o-ring groove is formed on the side of the sealing port close to the center, and branch fine grooves are formed in the side wall of the o-ring groove. The application tests whether the rubber ring in the o-ring groove has a gap by using the input gas, so that the sealing performance of the connection part of the testing structure can be tested during installation or subsequent maintenance work, and the pressure control of the connected structure of the flow control valve end or the reduction of pressure caused by the reduction of the sealing performance of the structure can be avoided, so that the normal use is not affected.

Description

Technical Field

[0001] This invention relates to the field of fracturing wellhead technology, specifically large-diameter fracturing wellheads. Background Technology

[0002] A fracturing wellhead is a device installed at the wellhead during fracturing operations in oil and gas extraction. It is a key piece of equipment used to withstand pressure, control fluids, and provide other functions required for operations such as hydraulic fracturing and acidizing in oil and gas wells. The fracturing wellhead is a crucial component in oil and gas well fracturing operations, and it needs to have high pressure resistance, reliable safety devices, and the ability to control fluid flow to ensure safety and efficiency during the operation.

[0003] Patent CN202755944U discloses a large-diameter fracturing wellhead device, which includes a four-way tubing head connected to the wellhead. A gate valve and a flange are respectively installed on the two adjacent ports of the tubing head connected to the wellhead. A manual flat valve, a first hydraulic flat valve, a fracturing six-way valve, and a second hydraulic flat valve are sequentially connected to the ports of the tubing head opposite the wellhead. The diameter of the manual flat valve, the first hydraulic flat valve, and the second hydraulic flat valve is 130mm. The valve pressure of the manual flat valve, the first hydraulic flat valve, and the second hydraulic flat valve is 105MPa. This patent is applicable to 130mm large-diameter fracturing wellheads, meeting the current needs of shale oil (gas) well fracturing operations. The first and second hydraulically operated flat valves can be remotely operated. Additionally, a manual flat valve for close-range operation is also provided. By using a commercially available ball screw and gear transmission, the manual flat valve significantly reduces the opening and closing torque, making operation easier and more convenient. However, this patent has the limitation of not being able to determine whether the connecting seal is aged or whether the connection is intact. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a large-diameter fracturing wellhead, solving the problems mentioned in the background section.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: a large-diameter fracturing wellhead, including a support frame, a casing structure is provided on the inner side of the middle part of the support frame, flow control valves for controlling the fluid flow are installed on both sides of the casing structure, and a testing mechanism is connected between adjacent flow control valves;

[0006] The testing mechanism includes a sealed port, with deep annular grooves on both sides of the sealed port. A connecting pipe is fixedly connected to the outer surface of the sealed port. A rubber ring groove is formed near the center of the side of the sealed port. Branching grooves are formed on the side wall of the rubber ring groove. A test groove is fixedly connected to the bottom end of the rubber ring groove. A test hole through groove is formed on the inner wall of the test groove. A pressure plate is provided below the test hole through groove. An energized contact plate is provided below the pressure plate. A unit board is fixedly connected to the bottom end of the energized contact plate. A buzzer is installed above the unit board. A test end shell is slidably connected to the outer side of the pressure plate.

[0007] According to the above technical solution, the connecting pipe is connected to the inner side of the deep annular groove, the rubber ring groove is connected to the deep annular groove through a branch groove, the measuring hole through groove extends from the inside of the test groove to below the sealing port, a T-shaped block is fixedly connected to the top of the unit plate, and a small spring is provided on the top surface of the T-shaped block, with the two ends of the small spring fixedly connected to the T-shaped block and the contact pressure piece respectively, the test end shell is fixedly connected to the sealing port, and the measuring hole through groove extends from the test groove to the inner side of the test end shell with a cross-sectional shape of "8" through distribution, and air is introduced through the connecting pipe, using the introduced air to enter the deep annular groove of the sealing port, and the air in the deep annular groove is circulated... Air enters the rubber ring groove through the branch groove. If there is no gap between the rubber ring groove and the rubber ring, air cannot enter the rubber ring groove. If the flow control valve ends connected to both sides of the test mechanism are not properly connected, the rubber ring groove and the rubber ring will not be completely fitted or the rubber ring will age. The aged rubber ring will oxidize and harden, leaving a gap between it and the rubber ring groove. The gap between the rubber ring groove and the rubber ring will allow air in the branch groove to enter the test chamber through the rubber ring groove. Then, it enters the upper part of the contact plate through the test hole groove connected to the inside of the test chamber. The contact plate is pressed down by the air pressure and slides down the test end shell to contact the energized contact plate and squeeze the small spring, so that the buzzer on the unit board is in working condition.

[0008] According to the above technical solution, the pressure-sealing mechanism includes an output end shell, a flow-dividing baffle fixedly connected to the inner bottom surface of the output end shell, an upper through pipe fixedly connected to the bottom surface of the output end shell, a top cover provided above the flow-dividing baffle, and a switching valve fixedly connected above the top cover, a flow-through pipe fixedly connected to the top of the switching valve, a vent pipe fixedly connected to the side of the switching valve, a pressure-applying cylinder fixedly connected to the top of the flow-through pipe, a connector fixedly connected to the top of the pressure-applying cylinder, a pressure-receiving slider slidably connected to the inner wall of the connector, a thin rod fixedly connected to the center of the pressure-receiving slider, a top plug fixedly connected to the bottom surface of the pressure-receiving slider, a bottom plug provided below the top plug, a compression plug provided below the bottom plug, and a pressure-boosting pipe fixedly connected to the top of the connector.

[0009] According to the above technical solution, the switching valve is connected to the inside of the diversion partition through the top cover. An inclined slice is provided on the top side of the pressure-bearing slider. A branch pipe extends outward from the side of the upper through-pipe. A pressure spring is provided on the bottom side of the bottom plug, and both ends of the pressure spring are fixedly connected to the compression plug and the bottom plug, respectively. When testing is required, gas is introduced through the vent pipe. The gas passes through the vent pipe, through the switching valve, and into the inside of the diversion partition. The gas passes through the upper through-pipe and the connecting pipe connected to the side of the diversion partition. When the valve body inside the switching valve is in its normal, non-rotating state, the vent pipe and the diversion partition are in communication. At this time, the valve body inside the switching valve blocks the upper through-pipe. When the valve body inside the switching valve rotates, it blocks the vent pipe, making the through-pipe and the lower diversion partition in communication. When maintenance is required, the liquid flowing out through the sleeve structure... The liquid enters the inner tank through the drainage ring and the liquid inlet hole. Then, it flows into the connector through the pressurizing pipe connected to the inner tank. When the pressure slider in the connector is subjected to liquid pressure, it moves downward and pushes the connected top plug. As the pressure slider moves downward, the connector and the top plug are in a connected state. At this time, the liquid in the pressurizing pipe enters the top of the pressure cylinder through the connector. At this time, the liquid on the top plug enters the top of the bottom plug through the connecting hole. Then, the liquid between the bottom plug and the top plug increases, and the bottom plug slides down, pushing the pressure spring to compress. After the pressure spring is compressed, it pushes the squeeze plug to apply pressure. At this time, the squeeze plug squeezes the sealing grease inside the pressure cylinder and enters the output end shell through the connected flow pipe. Then, through the upper through pipe and the connecting pipe connected to the output end shell, it fills the gap of the rubber ring groove and fills the area around the rubber ring groove to prevent the aging rubber in the rubber ring groove from hardening and affecting the sealing of the connection.

[0010] According to the above technical solution, the sleeve structure includes a drainage ring, which is fixedly connected to the inner wall of the sleeve structure. A lower inner groove is opened inside the bottom end of the sleeve structure, and a liquid passage hole is opened on the inner wall of the lower inner groove. The liquid passage hole is connected to the pressure boosting pipe, and the pressure boosting pipe is fixedly connected to the sleeve structure.

[0011] According to the above technical solution, a connecting end is installed at the top of the sleeve structure, a flow limiting pipe is installed at the top of the connecting end, a pressure relief end is installed at the top of the flow limiting pipe, and a one-way valve end is installed at the top of the pressure relief end.

[0012] According to the above technical solution, the single-way valve end includes a single-way port, a sealing cover is slidably connected to the bottom outer side of the single-way port, a sealing strip is fixedly connected to the top inner side of the sealing cover, a liquid passage groove is opened on the side of the sealing cover, a return spring is provided on the outer side of the single-way port, and the return spring is fixedly connected to the single-way port and the sealing cover.

[0013] According to the above technical solution, the pressure relief end includes a pressure relief cylinder, an installation screw cylinder is slidably connected to the outer side of the pressure relief cylinder, a spring is fixedly connected to the bottom end of the pressure relief cylinder, a strong spring is provided between the spring and the installation screw cylinder, and the two ends of the strong spring are fixedly connected to the spring and the installation screw cylinder respectively. The pressure relief cylinder has an inner cavity, and a pressure relief hole is opened on the outer side of the top end of the pressure relief cylinder. When it is necessary to introduce pressure-controlled fluid into the well connected to the casing structure, the external connection pipe head for fracturing fluid supply is inserted into the single-way valve end, and the pipe head contacts the sealing cover to pull the return spring. At this time, the sealing cover communicates with the inside of the single-way valve end through the side fluid passage to deliver fracturing fluid. The fluid returning from the well flows through... When the pressure inside the casing structure is too high, the liquid enters the flow control valve through the casing structure and is drawn out by the flow control valve. When the liquid pressure inside the casing structure is high, the liquid flows through the connection end and the flow limiting pipe into the pressure relief end and impacts the sealing cover, causing the sealing cover to be pressed upward and close the liquid passage on the sealing cover with the single port, facilitating the quick connection and closure of the single port. Thus, the sealing cover is automatically closed when the liquid flows back. Subsequently, the hydraulic pressure at the top of the single valve end and the pressure relief end gradually increases. When the pressure reaches a certain value, the liquid will squeeze the inner cavity of the pressure relief cylinder, causing the pressure relief cylinder to drive the spring to compress and contract the strong spring. Then, the pressure relief cylinder is squeezed upward and the pressure relief hole is moved out of the installation screw to relieve the pressure inside the pressure relief end.

[0014] This invention provides a large-diameter fracturing wellhead. It has the following beneficial effects:

[0015] This invention, by incorporating a sealing port, deep annular groove, connecting pipe, rubber ring groove, branch groove, test groove, test hole through groove, test end shell, buzzer, energized contact piece, unit small plate, and pressure contact piece, uses an alarm to indicate potential sealing safety hazards in the connection structure. The alarm only indicates the location of the sealing problem, facilitating subsequent inspection and maintenance. Simultaneously, by introducing gas to test whether there are gaps in the rubber ring within the rubber ring groove, the sealing performance of the structural connection can be tested during installation or subsequent maintenance work, preventing reduced structural sealing from causing uncontrolled pressure or pressure reduction in the structure connected to the flow control valve end, thus affecting normal use. Furthermore, the support frame and support plate provide support for the flow control valve ends installed on both sides of the sleeve structure, preventing the flow control valve ends from affecting the sealing performance between the flow control valve ends and the sleeve structure under gravity. This also facilitates the installation of the flow control valve ends, making it easier for bolts to pass through and align.

[0016] This invention comprises an output end shell, a flow divider, a switching valve, a vent pipe, a flow pipe, a pressure cylinder, an upper pipe, a booster pipe, a connector, a pressure-bearing slider, a thin rod, a top plug, a bottom plug, and a compression plug. The rubber ring groove is filled around the compression plug to prevent the hardening of aged rubber within the groove from affecting the sealing performance of the connection. The hydraulic pressure generated by the flowing liquid within the sleeve structure stores the spring force of the pressure spring, enabling the compression plug to compress the sealing grease within the pressure cylinder to maintain long-term operation without additional drive. Furthermore, it automatically replenishes the seal when gaps appear in the rubber ring groove, improving the sealing performance of the structural connection and reducing the risk of leakage due to aging of the sealing ring.

[0017] This invention comprises a single-port, a sealed cover, a sealing strip, a liquid passage groove, a pressure relief end, a pressure relief cylinder, a spring, a mounting screw, a pressure relief hole, and an inner cavity. Liquid flows through the connecting end and the flow-limiting pipe into the pressure relief end and impacts the sealed cover, causing the sealed cover to be pressurized and moved upward, allowing the liquid passage groove on the sealed cover to close with the single-port, facilitating the quick connection and closure of the single-port. At the same time, moving the pressure relief hole out of the mounting screw relieves the pressure inside the pressure relief end. By relieving the internal pressure of the pressure relief end, it prevents excessive pressure inside the pressure relief end from causing structural cracking at the connection between the pressure relief end and the single-port valve end, and alleviates the drainage pressure inside the flow control valve end. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall frontal three-dimensional structure of the present invention;

[0019] Figure 2 This is a schematic diagram of the overall rear-view three-dimensional structure of the present invention;

[0020] Figure 3 This is a schematic diagram of the overall testing mechanism of the present invention;

[0021] Figure 4 This invention as a whole Figure 3 A magnified structural diagram of A in the middle;

[0022] Figure 5 This is a schematic diagram of the overall pressure-sealing mechanism of the present invention;

[0023] Figure 6 This invention as a whole Figure 5 A magnified structural diagram of B in the diagram;

[0024] Figure 7 This invention as a whole Figure 5 A magnified structural diagram of C;

[0025] Figure 8 This is a schematic diagram of the overall sleeve structure of the present invention;

[0026] Figure 9 This invention as a whole Figure 8 A magnified structural diagram of D in the diagram;

[0027] Figure 10 This is a schematic diagram of the overall single-port structure of the present invention;

[0028] Figure 11 This is a schematic diagram of the overall pressure relief cylinder of the present invention.

[0029] In the diagram: 1. Support frame; 2. Support plate; 3. Sleeve structure; 31. Drain ring; 32. Liquid passage hole; 33. Inner groove; 4. Flow control valve end; 5. Test mechanism; 51. Sealing port; 52. Deep annular groove; 53. Connecting pipe; 54. Rubber ring groove; 55. Branch groove; 56. Test groove; 57. Test hole through groove; 58. Test end shell; 59. Buzzer; 510. Electrical contact piece; 511. Unit board; 512. Contact pressure piece; 6. Pressure sealing mechanism; 61. Output end shell; 62. Diverter plate; 63. Cutting... 64. Valve replacement; 65. Vent pipe; 66. Flow pipe; 67. Pressure cylinder; 68. Top pipe; 69. Pressure boosting pipe; 60. Connector; 610. Pressure-bearing slider; 611. Thin rod; 612. Top plug; 613. Bottom plug; 614. Squeeze plug; 7. One-way valve end; 71. One-way port; 72. Sealing cover; 73. Sealing strip; 74. Liquid passage groove; 8. Pressure relief end; 81. Pressure relief cylinder; 82. Spring; 83. Mounting screw; 84. Pressure relief hole; 85. Inner cavity; 9. Connector end; 10. Flow limiting pipe. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0031] Please see Figure 1-11 An embodiment of the present invention is as follows: a large-diameter fracturing wellhead includes a support frame 1, a casing structure 3 is provided on the inner side of the middle part of the support frame 1, flow control valve ends 4 for controlling the fluid flow are installed on both sides of the casing structure 3, and a test mechanism 5 is connected between adjacent flow control valve ends 4.

[0032] The testing mechanism 5 includes a sealed port 51, with deep annular grooves 52 on both sides of the sealed port 51. A connecting pipe 53 is fixedly connected to the outer surface of the sealed port 51. A rubber ring groove 54 is formed near the center of the side of the sealed port 51. Branching grooves 55 are formed on the side wall of the rubber ring groove 54. A test groove 56 is fixedly connected to the bottom end of the rubber ring groove 54. A test hole through groove 57 is formed on the inner wall of the test groove 56. A pressure plate 512 is arranged below the test hole through groove 57. An energized contact plate 510 is arranged below the pressure plate 512. A unit board 511 is fixedly connected to the bottom end of the energized contact plate 510. A buzzer 59 is installed above the unit board 511. A test end shell 58 is slidably connected to the outer side of the pressure plate 512. The through pipe 53 is connected to the inner side of the deep annular groove 52. The rubber ring groove 54 is connected to the deep annular groove 52 through the branch groove 55. The test hole through groove 57 extends from the inside of the test groove 56 to the bottom of the sealing port 51. A T-shaped block is fixedly connected to the top of the unit plate 511, and a small spring is provided on the top surface of the T-shaped block. The two ends of the small spring are fixedly connected to the T-shaped block and the contact plate 512, respectively. The test end shell 58 is fixedly connected to the sealing port 51. The test hole through groove 57 extends from the test groove 56 to the inside of the test end shell 58. The cross-sectional shape of the test hole through groove 57 is "eight" shaped. Air is introduced through the through pipe 53 and enters the deep annular groove 52 of the sealing port 51. The air in the deep annular groove 52 enters the rubber ring groove 54 through the branch groove 55. If there is no gap between the rubber ring groove 54 and the rubber ring, air cannot enter the rubber ring groove 54. If the flow control valve ends 4 connected to both sides of the test mechanism 5 are not properly connected, the rubber ring groove 54 and the rubber ring will not be completely fitted, or the rubber ring will age. The aged rubber ring will oxidize and harden, leaving a gap between it and the rubber ring groove 54. This gap will allow air in the branch groove 55 to enter the test groove 56 through the rubber ring groove 54. Then, it will enter the upper part of the contact plate 512 through the test hole through groove 57 connected to the inner side of the test groove 56. The contact plate 512, under air pressure, slides down the test end shell 58 to contact the energized contact plate 510 and squeeze the small spring, so that the buzzer 59 on the unit board 511 is in working condition. In operation, an alarm is used to indicate a potential sealing safety hazard in the connection structure. The alarm only indicates the location of the sealing problem for subsequent inspection and maintenance. At the same time, gas is introduced to test whether there is a gap in the rubber ring in the rubber ring groove 54. This allows for testing the sealing performance of the structural connection during installation or subsequent maintenance, preventing a decrease in structural sealing performance from causing uncontrolled pressure or pressure reduction in the structure connected to the flow control valve end 4, which would affect normal use. In addition, the support frame 1 and support plate 2 provide support for the flow control valve end 4 installed on both sides of the sleeve structure 3, preventing the flow control valve end 4 from affecting the sealing performance between it and the sleeve structure 3 under gravity. This also facilitates the installation of the flow control valve end 4, making it easier for bolts to pass through and align.

[0033] The pressure-sealing mechanism 6 includes an output end shell 61. A flow divider 62 is fixedly connected to the inner bottom surface of the output end shell 61. An upper passage pipe 67 is fixedly connected to the bottom surface of the output end shell 61. A top cover is provided above the flow divider 62, and a switching valve 63 is fixedly connected to the top of the top cover. A flow passage pipe 65 is fixedly connected to the top of the switching valve 63. A vent pipe 64 is fixedly connected to the side of the switching valve 63. A pressure cylinder 66 is fixedly connected to the top of the flow passage pipe 65. A connector 69 is fixedly connected to the top of the pressure cylinder 66. A pressure-receiving slider 610 is slidably connected to the inner wall of the connector 69. A thin rod 611 is fixedly connected to the center of the pressure-receiving slider 610. A top plug 612 is fixedly connected to the bottom surface of the pressure-receiving slider 610. A bottom plug 613 is provided below the top plug 612. A compression plug 614 is located below the plug 613. A pressure boosting pipe 68 is fixedly connected to the top of the connector 69. The switching valve 63 is connected to the inside of the diversion partition 62 through the top cover. An inclined slice is provided on the top side of the pressure slider 610. A branch pipe extending outward is provided on the side of the upper pipe 67. A pressure spring is provided on the bottom side of the bottom plug 613, and the two ends of the pressure spring are fixedly connected to the compression plug 614 and the bottom plug 613, respectively. When testing is required, gas is introduced through the vent pipe 64. The gas passes through the vent pipe 64, the switching valve 63, and enters the inside of the diversion partition 62. The gas passes through the upper pipe 67 and the connecting pipe 53 connected to the side of the diversion partition 62. When the valve body inside the switching valve 63 is in the normal state without rotation, the vent pipe 64 and the diversion partition are connected. When valve 62 is in a connected state, the valve body inside the switching valve 63 blocks the upper flow pipe 65. When the valve body inside the switching valve 63 rotates, it blocks the vent pipe 64, making the flow pipe 65 connected to the lower flow divider 62. The sleeve structure 3 includes a guide ring 31, which is fixedly connected to the inner wall of the sleeve structure 3. The bottom end of the sleeve structure 3 has a lower inner groove 33, and the inner wall of the lower inner groove 33 has a liquid passage hole 32. The liquid passage hole 32 is connected to the pressure boosting pipe 68, which is fixedly connected to the sleeve structure 3. The liquid flowing out of the sleeve structure 3 passes through the guide ring 31, enters the liquid passage hole 32, and then enters the inner groove 33. It then passes through the pressure boosting pipe 68 connected to the inner groove 33 and enters the connector 69. The pressure-bearing slider 61 in the connector 69... When subjected to liquid pressure, the slider 610 moves downward, pushing the connected top stopper 612. As the pressure slider 610 moves downward, the connector 69 and the top stopper 612 are in communication. At this time, the liquid in the booster pipe 68 enters the top of the pressure cylinder 66 through the connector 69. Meanwhile, the liquid on the top stopper 612 enters the area above the bottom stopper 613 through the connecting hole. Subsequently, the liquid between the bottom stopper 613 and the top stopper 612 increases, causing the bottom stopper 613 to slide down and compress the pressure spring. After compression, the pressure spring pushes the squeeze stopper 614 to apply pressure. At this time, the squeeze stopper 614 squeezes the sealing grease inside the pressure cylinder 66 and enters the output end housing 61 through the connected flow pipe 65. Then, through the upper through pipe 67 and the connecting pipe 53 connected to the output end housing 61, it fills the gap in the rubber ring groove 54.The rubber ring groove 54 is filled to prevent the aging rubber inside the groove from hardening and affecting the sealing performance of the connection. The hydraulic pressure generated by the flowing liquid inside the sleeve structure 3 stores the spring force, allowing the compression plug 614 to compress the sealing grease inside the pressure cylinder 66, maintaining long-term operation without additional drive. It also automatically replenishes the sealant when gaps appear in the rubber ring groove 54, improving the sealing performance of the structural connection and reducing the risk of leakage due to aging of the sealing ring.

[0034] The top end of the sleeve structure 3 is equipped with a connection end 9, the top end of the connection end 9 is equipped with a flow limiting pipe 10, the top end of the flow limiting pipe 10 is equipped with a pressure relief end 8, and the top end of the pressure relief end 8 is equipped with a one-way valve end 7.

[0035] The single-way valve end 7 includes a single-way port 71. A sealing cover 72 is slidably connected to the outer bottom end of the single-way port 71. A sealing strip 73 is fixedly connected to the inner top surface of the sealing cover 72. A liquid passage slot 74 is opened on the side of the sealing cover 72. A return spring is provided on the outer side of the single-way port 71, and the return spring is fixedly connected to the single-way port 71 and the sealing cover 72. The pressure relief end 8 includes a pressure relief cylinder 81. A mounting screw cylinder 83 is slidably connected to the outer side of the pressure relief cylinder 81. A spring plate 82 is fixedly connected to the bottom end of the pressure relief cylinder 81. The spring plate 82 and... A strong spring is installed between the mounting screws 83, and the two ends of the strong spring are fixedly connected to the spring plate 82 and the mounting screws 83 respectively. The pressure relief cylinder 81 has an inner cavity 85, and a pressure relief hole 84 is opened on the outer side of the top of the pressure relief cylinder 81. When it is necessary to introduce pressure-controlled fluid into the well connected to the casing structure 3, the external connection pipe head for fracturing fluid supply is inserted into the single-way valve end 7, and the pipe head contacts the sealing cover 72 to pull the return spring. At this time, the sealing cover 72 communicates with the inside of the single-way valve end 7 through the side fluid passage 74 to transport fluid. When the pressure of the fracturing fluid injected into the casing structure 3 through the well return fluid is too high, it enters the control valve end 4 through the casing structure 3 and is drawn out by the control valve end 4. When the fluid pressure inside the casing structure 3 is high, the fluid flows through the connection end 9 and the flow restriction pipe 10 into the pressure relief end 8, impacting the sealing cover 72. This causes the sealing cover 72 to be pressurized and moved upward, closing the fluid passage 74 on the sealing cover 72 with the single-port 71. This facilitates the quick connection and closure of the single-port 71, thereby automatically closing the sealing cover 72 during fluid return. 2. Subsequently, the hydraulic pressure at the top of the single-way valve end 7 and the pressure relief end 8 gradually increases. When the pressure reaches a certain value, the liquid will squeeze the inner cavity 85 inside the pressure relief cylinder 81, causing the pressure relief cylinder 81 to drive the spring plate 82 to compress and contract the strong spring. Then, the pressure relief cylinder 81 is squeezed upward to move the pressure relief hole 84 out of the mounting screw cylinder 83 to relieve the pressure inside the pressure relief end 8. By relieving the internal pressure of the pressure relief end 8, the excessive pressure inside the pressure relief end 8 is prevented from causing the structure at the connection between the pressure relief end 8 and the single-way valve end 7 to break, and the drainage pressure inside the flow control valve end 4 is relieved.

[0036] Working principle: Air is introduced through the connecting pipe 53 and enters the deep annular groove 52 of the sealed port 51. The air in the deep annular groove 52 enters the rubber ring groove 54 through the branch groove 55. If there is no gap between the rubber ring groove 54 and the rubber ring, the air cannot enter the rubber ring groove 54. If the flow control valve ends 4 connected to both sides of the test mechanism 5 are not properly connected, the rubber ring groove 54 and the rubber ring will not be completely fitted, or the rubber ring will age. The aged rubber ring will oxidize and harden, leaving a gap between it and the rubber ring groove 54. The gap between the rubber ring groove 54 and the rubber ring allows the air in the branch groove 55 to enter the test groove 56 through the rubber ring groove 54. Then, it enters the upper part of the contact plate 512 through the test hole through groove 57 connected to the inner side of the test groove 56. The contact plate 512 is pressed down by the air pressure and slides down the test end shell 58 to contact the energized contact. The plate 510 squeezes the small spring, causing the buzzer 59 on the unit plate 511 to be in working condition. The alarm indicates that there is a potential safety hazard in the sealing structure at this point. The alarm only indicates the location of the sealing problem, so as to facilitate subsequent inspection and maintenance. At the same time, the gas is introduced to test whether there is a gap in the rubber ring in the rubber ring groove 54. This is to test the sealing of the structural connection during installation or subsequent maintenance, so as to avoid the pressure loss or pressure reduction of the structure connected to the flow control valve end 4 due to reduced structural sealing, which would affect normal use. In addition, the support frame 1 and support plate 2 provide support for the flow control valve end 4 installed on both sides of the sleeve structure 3, so as to prevent the flow control valve end 4 from affecting the sealing between the flow control valve end 4 and the sleeve structure 3 under the action of gravity. It also facilitates the installation of the flow control valve end 4, making it easier for the bolts to pass through and be aligned.

[0037] When testing is required, gas is introduced through the vent pipe 64. The gas passes through the vent pipe 64, then through the switching valve 63, and enters the flow divider 62. The gas then passes through the upper through pipe 67 and the connecting pipe 53 connected to the side of the flow divider 62. When the valve body of the switching valve 63 is in its normal, non-rotating state, the vent pipe 64 and the flow divider 62 are in communication. At this time, the valve body of the switching valve 63 blocks the upper flow pipe 65. When the valve body of the switching valve 63 rotates, it blocks the vent pipe 64, causing the flow pipe 65 to connect with the upper flow pipe 65. The lower diversion baffle 62 is in a connected state. When maintenance is required, the liquid flowing out through the sleeve structure 3 passes through the guide ring 31 into the liquid passage hole 32 and then into the inner groove 33. It then flows through the pressure boosting pipe 68 connected to the inner groove 33 into the connector 69. The pressure-bearing slider 610 in the connector 69 moves downward under liquid pressure, pushing the connected top plug 612. As the pressure-bearing slider 610 moves downward, the connector 69 and the top plug 612 are in a connected state. At this time, the liquid in the pressure boosting pipe 68 flows through... The liquid enters the top of the pressure cylinder 66 through the connector 69. At this time, the liquid on the top plug 612 enters the area above the bottom plug 613 through the connecting hole. Then, the liquid between the bottom plug 613 and the top plug 612 increases, and the bottom plug 613 slides down, pushing the pressure spring to compress. After the pressure spring is compressed, it pushes the squeeze plug 614 to apply pressure. At this time, the squeeze plug 614 squeezes the sealing grease inside the pressure cylinder 66 and enters the output end shell 61 through the connected flow pipe 65. Then, through the upper through pipe 67 and the connecting pipe 53 connected to the output end shell 61, it fills the gap in the rubber ring groove 54. The filling around the rubber ring groove 54 prevents the aging rubber in the rubber ring groove 54 from hardening and affecting the sealing performance of the connection. The hydraulic pressure formed by the liquid flowing in the sleeve structure 3 stores the spring force of the pressure spring, so that the squeeze plug 614 can squeeze the sealing grease in the pressure cylinder 66 to maintain long-term operation without additional drive. It can also automatically replenish after the rubber ring groove 54 has a gap, improve the sealing performance of the structural connection, and reduce the risk of leakage due to the aging of the sealing ring.

[0038] When it is necessary to introduce pressure-pressurized fluid into the well connected to the casing structure 3, the external connecting pipe head for fracturing fluid supply is inserted into the single-way valve end 7, and the pipe head contacts the sealing cover 72, causing the return spring to be stretched. At this time, the sealing cover 72 communicates with the inside of the single-way valve end 7 through the side fluid passage 74 to deliver fracturing fluid. When the pressure of the fluid flowing back from the well into the casing structure 3 is too high, it enters the control valve end 4 through the casing structure 3 and is drawn out by the control valve end 4. When the fluid pressure inside the casing structure 3 is high, the fluid flows through the connecting end 9 and the flow limiting pipe 10 into the pressure relief end 8, impacting the sealing cover 72, causing the sealing cover 72 to be pressurized and moved upward, allowing the fluid to flow through the sealing cover 72. The slot 74 closes with the single-way port 71, facilitating quick connection and closure of the single-way port 71. This allows the sealing cover 72 to close automatically during liquid backflow. Subsequently, the hydraulic pressure at the top of the single-way valve end 7 and the pressure relief end 8 gradually increases. When the pressure reaches a certain value, the liquid will squeeze the inner cavity 85 inside the pressure relief cylinder 81, causing the pressure relief cylinder 81 to drive the spring 82 to compress and contract the strong spring. Then, the pressure relief cylinder 81 is squeezed upwards, moving the pressure relief hole 84 out of the mounting screw 83 to relieve the pressure inside the pressure relief end 8. By relieving the internal pressure of the pressure relief end 8, excessive pressure inside the pressure relief end 8 is avoided, which could cause structural collapse at the connection between the pressure relief end 8 and the single-way valve end 7. This also relieves the drainage pressure inside the flow control valve end 4.

[0039] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A large-diameter fracturing wellhead, including a support frame (1), characterized in that: The bottom end of the support frame (1) is fixedly connected to a support plate (2), a sleeve structure (3) is provided on the inner side of the middle part of the support frame (1), flow control valve ends (4) for controlling the liquid flow are installed on both sides of the sleeve structure (3), a test mechanism (5) is connected between adjacent flow control valve ends (4), and a pressure sealing mechanism (6) is provided on the rear side of the support frame (1). The testing mechanism (5) includes a sealed port (51), with deep annular grooves (52) on both sides of the sealed port (51). A connecting pipe (53) is fixedly connected to the outer surface of the sealed port (51). A rubber ring groove (54) is opened near the center on the side of the sealed port (51). A branch groove (55) is opened on the side wall of the rubber ring groove (54). A test groove (56) is fixedly connected to the bottom end of the rubber ring groove (54). A test hole through groove (57) is opened on the inner wall of the test groove (56). A pressure plate (512) is provided below the test hole through groove (57). An energized contact plate (510) is provided below the pressure plate (512). A unit board (511) is fixedly connected to the bottom end of the energized contact plate (510). A buzzer (59) is installed above the unit board (511). A test end shell (58) is slidably connected to the outer side of the pressure plate (512). The connecting pipe (53) is connected to the inner side of the deep annular groove (52), the rubber ring groove (54) is connected to the deep annular groove (52) through the branch groove (55), the measuring hole through groove (57) extends from the inside of the test groove (56) to the bottom of the sealing port (51), a T-shaped block is fixedly connected to the top of the unit plate (511), and a small spring is provided on the top surface of the T-shaped block, and the two ends of the small spring are fixedly connected to the T-shaped block and the contact pressure plate (512) respectively. The test end shell (58) is fixedly connected to the sealing port (51), and the measuring hole through groove (57) extends from the test groove (56) to the inside of the test end shell (58) with a cross-sectional shape of "eight" through distribution; The pressure-sealing mechanism (6) includes an output end shell (61), a flow divider (62) is fixedly connected to the inner bottom surface of the output end shell (61), an upper passage pipe (67) is fixedly connected to the bottom surface of the output end shell (61), a top cover is provided above the flow divider (62), and a switching valve (63) is fixedly connected above the top cover. A flow pipe (65) is fixedly connected to the top of the switching valve (63), a vent pipe (64) is fixedly connected to the side of the switching valve (63), a pressure cylinder (66) is fixedly connected to the top of the flow pipe (65), and a connector (69) is fixedly connected to the top of the pressure cylinder (66). The inner wall of the connector (69) is slidably connected to a pressure-bearing slider (610), a thin rod (611) is fixedly connected to the center of the pressure-bearing slider (610), a top plug (612) is fixedly connected to the bottom surface of the pressure-bearing slider (610), a bottom plug (613) is provided below the top plug (612), a compression plug (614) is provided below the bottom plug (613), and a pressure boosting tube (68) is fixedly connected to the top of the connector (69).

2. The large-diameter fracturing wellhead according to claim 1, characterized in that: The switching valve (63) is connected to the inside of the diversion partition (62) through the top cover. The top side of the pressure slider (610) is provided with an inclined slice. The side of the upper pipe (67) is provided with a branch pipe extending outward. The bottom plug (613) is provided with a pressure spring, and the two ends of the pressure spring are fixedly connected to the compression plug (614) and the bottom plug (613) respectively.

3. The large-diameter fracturing wellhead according to claim 2, characterized in that: The sleeve structure (3) includes a drainage ring (31), which is fixedly connected to the inner wall of the sleeve structure (3). The bottom end of the sleeve structure (3) has a lower inner groove (33), and the inner wall of the lower inner groove (33) has a liquid passage hole (32). The liquid passage hole (32) is connected to the pressure boosting pipe (68), and the pressure boosting pipe (68) is fixedly connected to the sleeve structure (3).

4. The large-diameter fracturing wellhead according to claim 1, characterized in that: The top end of the sleeve structure (3) is equipped with a connecting end (9), the top end of the connecting end (9) is equipped with a flow limiting pipe (10), the top end of the flow limiting pipe (10) is equipped with a pressure relief end (8), and the top end of the pressure relief end (8) is equipped with a one-way valve end (7).

5. The large-diameter fracturing wellhead according to claim 4, characterized in that: The single-way valve end (7) includes a single-way port (71), a sealing cover (72) is slidably connected to the bottom outer side of the single-way port (71), a sealing strip (73) is fixedly connected to the top inner side of the sealing cover (72), a liquid passage slot (74) is opened on the side of the sealing cover (72), a return spring is provided on the outer side of the single-way port (71), and the return spring is fixedly connected to the single-way port (71) and the sealing cover (72).

6. The large-diameter fracturing wellhead according to claim 4, characterized in that: The pressure relief end (8) includes a pressure relief cylinder (81), a mounting screw cylinder (83) is slidably connected to the outer side of the pressure relief cylinder (81), a spring piece (82) is fixedly connected to the bottom end of the pressure relief cylinder (81), a strong spring is provided between the spring piece (82) and the mounting screw cylinder (83), and the two ends of the strong spring are fixedly connected to the spring piece (82) and the mounting screw cylinder (83) respectively. The pressure relief cylinder (81) has an inner cavity (85) inside, and a pressure relief hole (84) is opened on the outer side of the top end of the pressure relief cylinder (81).

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