Large-drift-diameter fracturing wellhead

Abstract

The invention discloses a large-drift-diameter fracturing wellhead, and relates to the technical field of fracturing wells.The large-drift-diameter fracturing wellhead comprises a supporting frame, a sleeve structure is arranged on the inner side of the middle of the supporting frame, flow control valve ends used for controlling liquid flux are installed on the two sides of the sleeve structure, and a testing mechanism is connected between every two adjacent flow control valve ends; the testing mechanism comprises a sealing port, deep ring grooves are formed in the two sides of the sealing port, a communicating pipe is fixedly connected to the outer surface of the sealing port, a rubber ring groove is formed in the position, close to the center, of the side face of the sealing port, and branch thin grooves are formed in the side wall of the rubber ring groove. According to the invention, whether the rubber ring in the rubber ring groove has a gap or not is tested by introducing gas, so that the sealing performance of the connection part of the structure is tested during installation or subsequent maintenance work, and the situation that the normal use is influenced by out-of-control pressure or pressure reduction of the connection structure at the end of the flow control valve caused by reduction of the sealing performance of the structure is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of fracturing wellheads, in particular to a large-diameter fracturing wellhead. Background Art

[0002] A fracturing wellhead refers to the equipment installed at the wellhead during fracturing operations in the process of oil and gas extraction. It is a key equipment used to bear pressure, control fluid and provide other functions required for oil and gas wells during hydraulic fracturing, acidizing and other operations. The fracturing wellhead is a vital component for oil and gas wells during fracturing operations. It needs to have high-intensity pressure-bearing capacity, reliable safety devices and the ability to control fluid flow to ensure safety and efficiency during the operation.

[0003] The patent with announcement number CN202755944U discloses a large-diameter fracturing wellhead device, which includes a four-way oil pipe head connected to the wellhead, and gate valves and flanges are respectively provided on the two adjacent ports of the oil pipe 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 opposite to the wellhead on the oil pipe head; the diameters of the manual flat valve, the first hydraulic flat valve, and the second hydraulic flat valve are all 130mm; the valve pressures of the manual flat valve, the first hydraulic flat valve, and the second hydraulic flat valve are 105MPa. This patent is applicable to 130mm large-diameter fracturing wellheads, meeting the needs of current shale oil (gas) well fracturing construction; the first hydraulic flat valve and the second hydraulic flat valve can be remotely operated; at the same time, a manual flat valve that can be operated at close range is also provided. By using the mature ball screw pair and gear combination transmission on the market for the manual flat valve, the switching torque is greatly reduced, and the operation is labor-saving and convenient. However, this patent has the problem of being unable to judge whether the connection seal ring is aged or whether the connection is intact. Summary of the invention

[0004] In view of the deficiencies of the prior art, the present invention provides a large-diameter fracturing wellhead, which solves the problems raised in the above-mentioned background technology.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: a large-diameter fracturing wellhead, comprising a support frame, wherein a casing structure is arranged inside the middle of the support frame, flow control valve ends for controlling liquid flux are installed on both sides of the casing structure, and a testing mechanism is connected between adjacent flow control valve ends; The testing mechanism includes a sealing port, deep ring grooves are provided on both sides of the sealing port, a connecting pipe is fixedly connected to the outer surface of the sealing port, a rubber ring groove is provided near the center of the side of the sealing port, a branch groove is provided on the side wall of the rubber ring groove, a test slot is fixedly connected to the bottom end of the rubber ring groove, a measuring hole groove is provided on the inner wall of the test slot, a touch-pressure piece is provided below the measuring hole groove, an energized contact piece is provided below the touch-pressure piece, a unit small board is fixedly connected to the bottom end of the energized contact piece, a buzzer is installed above the unit small board, and a test end shell is slidably connected to the outer side of the touch-pressure piece.

[0006] According to the above technical solution, the connecting pipe is connected with the inner side of the deep annular groove, the rubber ring groove is connected with the deep annular groove through a branch groove, the measuring hole groove passes through the inside of the test groove to the bottom of the sealing port, a T-block is fixedly connected to the top of the unit small plate, and a small spring is provided on the top surface of the T-block, and the two ends of the small spring are respectively fixedly connected to the T-block and the touch-pressure piece, the test end shell is fixedly connected to the sealing port, the measuring hole groove passes through the test groove to the inside of the test end shell, and the cross-sectional shape of the measuring hole groove is distributed in an "eight" shape, and air is introduced through the connecting pipe, and the introduced air enters the deep annular groove of the sealing port, and the air in the deep annular groove is vented. The air passes through the branch groove and enters the rubber ring groove. If there is no gap between the rubber ring groove and the rubber ring, the air cannot enter the rubber ring groove. If the flow control valve ends connected on both sides of the test mechanism are not connected well, the rubber ring groove and the rubber ring will not fit completely or the rubber ring will age. The aged rubber ring will oxidize and harden, leaving a gap between the rubber ring groove and the rubber ring. The gap between the rubber ring groove and the rubber ring will allow the air in the branch groove to enter the test groove through the rubber ring groove, and then enter the top of the touch-pressure piece through the measuring hole groove connected to the inner side of the test groove. The touch-pressure piece is pressed by the air pressure to slide down along the test end shell to contact the energized contact piece and squeeze the small spring, so that the buzzer on the unit board is in working condition.

[0007] According to the above technical scheme, the sealing mechanism includes an output end shell, the inner bottom surface of the output end shell is fixedly connected with a diverter spacer, the bottom surface of the output end shell is fixedly connected with an upper through pipe, a top cover is arranged above the diverter spacer, and a switching valve is fixedly connected above the top cover, the top of the switching valve is fixedly connected with a flow pipe, the side of the switching valve is fixedly connected with a ventilation pipe, the top of the flow pipe is fixedly connected with a pressure cylinder, the top of the pressure cylinder is fixedly connected with a connecting head, the inner wall of the connecting head is slidably connected with a pressure slider, the center of the pressure slider is fixedly connected with a thin rod, the bottom surface of the pressure slider is fixedly connected with a top plug piece, a bottom plug piece is arranged below the top plug piece, an extrusion plug piece is arranged below the bottom plug piece, and the top of the connecting head is fixedly connected with a boosting pipe.

[0008] According to the above technical solution, the switching valve is connected with the inside of the diverter spacer through the top cover, the top side of the pressure-bearing sliding block is provided with an inclined slice, the side of the upper through pipe is provided with a branch pipe extending outward, the bottom side of the bottom plug is provided with a pressure spring, and the two ends of the pressure spring are respectively fixedly connected to the extrusion plug and the bottom plug. When testing is required, gas is introduced through the vent pipe, and the gas passes through the vent pipe through the switching valve into the inside of the diverter spacer, and the gas passes through the upper through pipe and the connecting pipe connected to the side of the diverter spacer. When the valve body in the switching valve is in a normal state without rotation, the vent pipe and the diverter spacer are in a connected state. At this time, the valve body in the switching valve blocks the upper flow pipe. When the valve body in the switching valve rotates, the valve body blocks the vent pipe, so that the flow pipe is in a connected state with the lower diverter spacer. When maintenance is required, the liquid flowing out through the sleeve structure is The liquid passes through the drainage ring and enters the inner groove through the liquid through the through hole, and then enters the connecting head through the boosting pipe connected to the inner groove. The pressure-bearing slider in the connecting head will move downward under the pressure of the liquid and push the connected top plug piece. As the pressure-bearing slider moves downward, the connecting head and the top of the top plug piece are in a connected state. At this time, the liquid in the boosting pipe enters the top of the pressure cylinder through the connecting head. At this time, the liquid on the top plug piece enters the top of the bottom plug piece through the connecting hole. Subsequently, the liquid between the bottom plug piece and the top plug piece increases, and the bottom plug piece slides down to push the pressure spring to compress. After the pressure spring is compressed, it will push the extrusion plug piece to apply pressure. At this time, the extrusion plug piece squeezes the sealing grease inside the pressure cylinder through the connected through flow pipe into the output end shell, and then fills the gap in the rubber ring groove through the upper through pipe and the connecting pipe connected to the output end shell. Filling is performed around the rubber ring groove to prevent the aging rubber in the rubber ring groove from hardening and affecting the sealing of the connection.

[0009] 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 hole is opened on the inner wall of the lower inner groove. The liquid hole is connected to the boosting pipe, and the boosting pipe is fixedly connected to the sleeve structure.

[0010] According to the above technical solution, a connecting end is installed at the top of the sleeve structure, a limiting flow tube is installed at the top of the connecting end, a pressure relief end is installed at the top of the limiting flow tube, and a one-way valve end is installed at the top of the pressure relief end.

[0011] According to the above technical solution, the one-way valve end includes a one-way port, the outer bottom end of the one-way port is slidably connected to a closing cover, the inner top surface of the closing cover is fixedly connected to a sealing strip, a liquid passage groove is provided on the side of the closing cover, a return spring is arranged on the outer side of the one-way port, and the return spring is fixedly connected to the one-way port and the closing cover.

[0012] According to the above technical solution, the pressure relief end includes a pressure relief cylinder, the outer side of the pressure relief cylinder is slidably connected with a mounting screw cylinder, the bottom end of the pressure relief cylinder is fixedly connected with a spring sheet, a strong spring is arranged between the spring sheet and the mounting screw cylinder, and the two ends of the strong spring are respectively fixedly connected with the spring sheet and the mounting screw cylinder, an inner cavity is arranged inside the pressure relief cylinder, a pressure relief hole is opened on the outer side of the top end of the pressure relief cylinder, when it is necessary to pass the pressure liquid into the well connected with the casing structure, the external connecting pipe head of the fracturing pressure supply is inserted into the one-way valve end, and the pipe head is contacted with the closing cover to pull the reset spring, at this time, the closing cover is connected with the inside of the one-way valve end through the side liquid passing groove to transport the fracturing fluid, and the reflux liquid in the well passes through When the pressure injected into the casing structure is too high, it enters the flow control valve end through the casing structure, and the underground liquid is led out by the flow control valve end. When the liquid pressure in the casing structure is high, the liquid flows through the connecting end and the flow limiting pipe into the pressure relief end to impact the closing cover, causing the closing cover to move upward under pressure, so that the liquid passing groove on the closing cover and the single-way port are closed, which facilitates the rapid connection and closure of the single-way port, thereby automatically closing the closing cover when the liquid flows back. Subsequently, the hydraulic pressure at the single-way valve end and the top of the pressure relief end gradually increases. When the pressure reaches a certain value, the liquid will squeeze the inner cavity in the pressure relief cylinder, causing the pressure relief cylinder to drive the spring to compress the strong spring and then squeeze the pressure relief cylinder upward to move the pressure relief hole out of the installation screw cylinder to relieve the pressure in the pressure relief end.

[0013] The present invention provides a large-diameter fracturing wellhead, which has the following beneficial effects: The present invention is provided with a sealing port, a deep ring groove, a connecting pipe, a rubber ring groove, a branch groove, a test groove, a hole measuring groove, a test end shell, a buzzer, an energized contact piece, a unit small board, and a touch-pressure piece. An alarm is used to prompt that there is a safety hazard of sealing in the connection structure at that location. The alarm only indicates the location where there is a sealing problem, so as to facilitate subsequent inspection and maintenance. At the same time, gas is passed to test whether there is a gap in the rubber ring in the rubber ring groove, so as to test the sealing of the structure connection during installation or subsequent maintenance work, so as to avoid the pressure of the structure connected to the flow control valve end being out of control or the pressure being reduced due to the reduction of the structural sealing, thereby affecting normal use. In addition, the support frame and the support plate play a supporting role for the flow control valve ends installed on both sides of the casing structure, so as to avoid the flow control valve ends affecting the sealing between the casing structure under the action of gravity, and the flow control valve ends can also be easily installed when they are installed, so as to facilitate the alignment of the bolts through. The present invention is provided with an output end shell, a flow dividing spacer, a switching valve, a vent pipe, a flow pipe, a pressure cylinder, an upper through pipe, a pressure-boosting pipe, a connector, a pressure-bearing slider, a thin rod, a top plug piece, a bottom plug piece, and an extrusion plug piece, which are filled around the rubber ring groove to prevent the aged rubber in the rubber ring groove from hardening and affecting the sealing of the connection. The hydraulic pressure formed by the flowing liquid in the sleeve structure is used to store the elastic force of the pressure spring, so that the extrusion plug piece can squeeze the sealing grease in the pressure cylinder to maintain long-term operation without additional drive, and can automatically replenish after a gap is generated in the rubber ring groove, thereby improving the sealing of the structural connection and reducing the risk of leakage caused by aging of the sealing ring. The present invention is provided with a single-way port, a closed cover, a sealing strip, a liquid-passing groove, a pressure relief end, a pressure relief cylinder, a spring piece, a mounting screw, a pressure relief hole, and an inner cavity. Liquid flows through the connecting end and the flow-limiting tube into the pressure relief end to impact the closed cover, so that the closed cover is pressed and moved upward, and the liquid-passing groove on the closed cover is closed with the single-way port, which facilitates the rapid connection and closure of the single-way port. At the same time, the pressure relief hole is moved out of the mounting screw to relieve the pressure in the pressure relief end. By relieving the internal pressure of the pressure relief end, it is avoided that the pressure inside the pressure relief end is excessively high, which may cause the structure at the connection between the pressure relief end and the single-way valve end to collapse, and the drainage pressure in the flow control valve end is relieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall front three-dimensional structure of the present invention; Figure 2 It is a schematic diagram of the overall rear-view stereoscopic structure of the present invention; Figure 3 It is a structural schematic diagram of the overall testing mechanism of the present invention; Figure 4 For the present invention as a whole Figure 3 A is a schematic diagram of the enlarged structure of the middle part; Figure 5 It is a structural schematic diagram of the integral pressing mechanism of the present invention; Figure 6 For the present invention as a whole Figure 5 Schematic diagram of the enlarged structure of B; Figure 7 For the present invention as a whole Figure 5 Schematic diagram of the enlarged structure of C; Figure 8 It is a structural schematic diagram of the overall casing structure of the present invention; Fig. 9 For the present invention as a whole Figure 8 Schematic diagram of the enlarged structure of D in the middle; Fig.10 It is a structural schematic diagram of the overall single-pass end of the present invention; Fig.11 It is a schematic structural diagram of the integral pressure relief cylinder of the present invention.

[0015] In the figure: 1, support frame; 2, support plate; 3, sleeve structure; 31, drainage ring; 32, liquid hole; 33, inner groove; 4, flow control valve end; 5, test mechanism; 51, sealing port; 52, deep ring groove; 53, connecting pipe; 54, rubber ring groove; 55, branch groove; 56, test groove; 57, measuring hole groove; 58, test end shell; 59, buzzer; 510, power contact piece; 511, unit small board; 512, touch pressure piece; 6, close pressure mechanism; 61, output end shell; 62, diversion spacer; 63, cut Change valve; 64, vent pipe; 65, flow pipe; 66, pressure cylinder; 67, upper pipe; 68, booster pipe; 69, connector; 610, pressure slider; 611, thin rod; 612, top plug; 613, bottom plug; 614, extrusion plug; 7, one-way valve end; 71, one-way port; 72, closure cover; 73, sealing strip; 74, liquid groove; 8, pressure relief end; 81, pressure relief cylinder; 82, spring piece; 83, mounting screw; 84, pressure relief hole; 85, inner cavity; 9, connecting end; 10, flow limiting tube. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0017] See also Figure 1-11 , an embodiment of the present invention is: a large-diameter fracturing wellhead, comprising a support frame 1, a casing structure 3 is arranged inside the middle of the support frame 1, flow control valve ends 4 for controlling liquid flux are installed on both sides of the casing structure 3, and a testing mechanism 5 is connected between adjacent flow control valve ends 4; The test mechanism 5 includes a sealing port 51, deep annular grooves 52 are provided on both sides of the sealing port 51, a connecting pipe 53 is fixedly connected to the outer surface of the sealing port 51, a rubber ring groove 54 is provided near the center of the side of the sealing port 51, a branch groove 55 is provided 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 measuring hole groove 57 is provided on the inner wall of the test groove 56, a touch-pressure sheet 512 is provided below the measuring hole groove 57, an energized contact sheet 510 is provided below the touch-pressure sheet 512, a unit small plate 511 is fixedly connected to the bottom end of the energized contact sheet 510, a buzzer 59 is installed above the unit small plate 511, a test end shell 58 is slidably connected to the outer side of the touch-pressure sheet 512, and a connecting rod 510 is provided below the touch-pressure sheet 512. The through pipe 53 is connected with the inner side of the deep annular groove 52, the rubber ring groove 54 is connected with the deep annular groove 52 through the branch groove 55, the measuring hole through groove 57 passes through the inside of the test groove 56 to the bottom of the sealing port 51, a T-block is fixedly connected above the unit small plate 511, and a small spring is arranged on the top surface of the T-block, and the two ends of the small spring are respectively fixedly connected with the T-block and the touch-pressing sheet 512, the test end shell 58 is fixedly connected with the sealing port 51, the measuring hole through groove 57 passes through the test groove 56 to the inside of the test end shell 58, and the cross-sectional shape is "eight" through distribution, the air is introduced through the connecting pipe 53, and the introduced air enters the deep annular groove 52 of the sealing port 51, and the air in the deep annular groove 52 enters the rubber ring 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 on both sides of the test mechanism 5 are not connected well, the rubber ring groove 54 and the rubber ring may not fit completely or the rubber ring may age. The aged rubber ring may oxidize and harden, and there may be a gap between the rubber ring groove 54 and the rubber ring. The gap between the rubber ring groove 54 and the rubber ring may allow the air in the branch groove 55 to enter the test groove 56 through the rubber ring groove 54, and then enter the top of the touch-press piece 512 through the measuring hole groove 57 connected to the inner side of the test groove 56. The touch-press piece 512 is pressed by the air pressure to slide down along the test end shell 58 to contact the energized contact piece 510 and squeeze the small spring, so that the buzzer 59 on the unit small board 511 is in the working state. In the working state, an alarm is used to prompt that there is a safety hazard in the sealing of the connection structure at that location. The alarm only indicates the location where the sealing problem exists for subsequent inspection and maintenance. At the same time, gas is passed to test whether there is a gap in the rubber ring in the rubber ring groove 54, so that during installation or subsequent maintenance work, the sealing of the structural connection can be tested to avoid the reduction of structural sealing resulting in the pressure of the structure connected to the flow control valve end 4 being out of control or the pressure being reduced to affect normal use. In addition, the support frame 1 and the support plate 2 support the flow control valve end 4 installed on both sides of the casing structure 3 to avoid the flow control valve end 4 affecting the sealing between the casing structure 3 under the action of gravity, and the flow control valve end 4 can also be easily installed when it is installed, so that the bolts can be easily passed through and aligned.

[0018] The sealing mechanism 6 includes an output end shell 61, the inner bottom surface of the output end shell 61 is fixedly connected with a flow dividing spacer 62, the bottom surface of the output end shell 61 is fixedly connected with an upper through pipe 67, a top cover is arranged above the flow dividing spacer 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, a connector 69 is fixedly connected to the top of the pressure cylinder 66, a pressure 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 slider 610, a top plug 612 is fixedly connected to the bottom surface of the pressure slider 610, a bottom plug 613 is arranged below the top plug 612, and a bottom plug 613 is arranged below the top plug 612. An extrusion plug 614 is provided below the plug 613, a boost pipe 68 is fixedly connected to the top of the connector 69, the switching valve 63 is connected to the inside of the diverter spacer 62 through the top cover, an inclined slice is provided on the top side of the pressure-bearing slider 610, a branch pipe extending outward is provided on the side of the upper through 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 respectively fixedly connected to the extrusion plug 614 and the bottom plug 613. When testing is required, gas is introduced through the vent pipe 64, and the gas passes through the vent pipe 64 through the switching valve 63 into the inside of the diverter spacer 62, and the gas passes through the upper through pipe 67 and the connecting pipe 53 connected to the side of the diverter spacer 62. When the valve body in the switching valve 63 is in a normal state without rotation, the vent pipe 64 and the diverter spacer are in a closed state. 62 is in a connected state, at which time the valve body in the switching valve 63 blocks the upper flow pipe 65. When the valve body in the switching valve 63 rotates, the valve body blocks the vent pipe 64, so that the flow pipe 65 is in a connected state with the lower diversion spacer 62. The sleeve structure 3 includes a drainage ring 31, and the drainage ring 31 is fixedly connected to the inner wall of the sleeve structure 3. A lower inner groove 33 is provided inside the bottom end of the sleeve structure 3. A liquid through hole 32 is provided on the inner wall of the lower inner groove 33. The liquid through hole 32 is connected to the boosting pipe 68. The boosting pipe 68 is fixedly connected to the sleeve structure 3. The liquid flowing out of the sleeve structure 3 passes through the drainage ring 31 and enters the liquid through hole 32 and enters the inner groove 33, and then passes through the boosting pipe 68 connected to the inner groove 33 into the connector 69. The pressure slider 61 in the connector 69 0 will move downwards after receiving the liquid pressure and push the connected top plug piece 612. As the pressure slider 610 moves downwards, the connector 69 is in a connected state with the top of the top plug piece 612. At this time, the liquid in the booster pipe 68 enters the top of the pressure cylinder 66 through the connector 69. At this time, the liquid on the top plug piece 612 enters the top of the bottom plug piece 613 through the connecting hole. Subsequently, the liquid between the bottom plug piece 613 and the top plug piece 612 increases. The bottom plug piece 613 slides down and pushes the pressure spring to compress. After the pressure spring is compressed, it pushes the squeeze plug piece 614 to apply pressure. At this time, the squeeze plug piece 614 squeezes the sealing grease inside the pressure cylinder 66 through the connected flow tube 65 into the output end shell 61, and then fills the gap in the rubber ring groove 54 through the upper through pipe 67 and the connecting pipe 53 connected to the output end shell 61.Filling around the rubber groove 54 prevents the aged rubber in the rubber groove 54 from hardening and affecting the sealing of the connection. The hydraulic pressure formed by the flowing liquid in the sleeve structure 3 is used to store elastic force for the pressure spring, so that the extrusion plug 614 can squeeze the sealing grease in the pressure cylinder 66 to maintain long-term operation without additional drive. It can automatically replenish after a gap is generated in the rubber groove 54, thereby improving the sealing of the structural connection and reducing the risk of leakage caused by aging of the sealing ring.

[0019] A connecting end 9 is installed at the top of the sleeve structure 3 , a flow limiting tube 10 is installed at the top of the connecting end 9 , a pressure relief end 8 is installed at the top of the flow limiting tube 10 , and a one-way valve end 7 is installed at the top of the pressure relief end 8 .

[0020] The one-way valve end 7 includes a one-way port 71, the outer bottom end of the one-way port 71 is slidably connected to a closing cover 72, the inner top surface of the closing cover 72 is fixedly connected to a sealing strip 73, the side of the closing cover 72 is provided with a liquid passage slot 74, the outer side of the one-way port 71 is provided with a return spring, and the return spring is fixedly connected to the one-way port 71 and the closing cover 72, the pressure relief end 8 includes a pressure relief cylinder 81, the outer side of the pressure relief cylinder 81 is slidably connected to a mounting screw cylinder 83, the bottom end of the pressure relief cylinder 81 is fixedly connected to a spring sheet 82, and the spring sheet 82 is fixedly connected to the A strong spring is arranged between the installation screw cylinder 83, and the two ends of the strong spring are fixedly connected to the spring piece 82 and the installation screw cylinder 83 respectively. The inner cavity 85 is arranged inside the pressure relief cylinder 81, and the outer side of the top of the pressure relief cylinder 81 is provided with a pressure relief hole 84. When it is necessary to pass the pressure liquid into the well connected to the casing structure 3, the external connection pipe head of the fracturing pressure supply liquid is inserted into the one-way valve end 7, and the pipe head is allowed to contact the sealing cover 72 to pull the reset spring. At this time, the sealing cover 72 is connected with the inside of the one-way valve end 7 through the side liquid passing groove 74 for delivery. When the pressure of the fracturing fluid injected by the reflux liquid in the well through the casing structure 3 is too high, the fracturing fluid enters the flow control valve end 4 through the casing structure 3, and the underground liquid is led out by the flow control valve end 4. When the pressure of the liquid in the casing structure 3 is high, the liquid flows through the connecting end 9 and the flow limiting pipe 10 into the pressure relief end 8 to impact the sealing cover 72, so that the sealing cover 72 moves upward under pressure, so that the liquid passing groove 74 on the sealing cover 72 is closed with the single-way port 71, which facilitates the quick connection and closing of the single-way port 71, thereby automatically closing the sealing cover 72 when the liquid refluxes. 2. Then, the hydraulic pressure at the top of the one-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 in the pressure relief cylinder 81, so that the pressure relief cylinder 81 drives the spring 82 to contract under pressure against the strong spring. Then, the pressure relief cylinder 81 is squeezed upward to move the pressure relief hole 84 out of the installation screw cylinder 83 to relieve the pressure in the pressure relief end 8. By relieving the internal pressure of the pressure relief end 8, the internal pressure of the pressure relief end 8 is avoided to be excessively high, which may cause the structure of the connection between the pressure relief end 8 and the one-way valve end 7 to collapse, and the drainage pressure in the flow control valve end 4 is relieved.

[0021] Working principle: air is introduced through the connecting pipe 53, and the introduced air 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, the air cannot enter the rubber ring groove 54. If the flow control valve ends 4 connected on both sides of the test mechanism 5 are not connected well, the rubber ring groove 54 and the rubber ring may not be fully fitted or the rubber ring may age. The aged rubber ring may oxidize and harden, and there may be a gap between the rubber ring groove 54 and the rubber ring. The gap between the rubber ring groove 54 and the rubber ring may allow the air in the branch groove 55 to enter the test groove 56 through the rubber ring groove 54, and then enter the top of the touch-pressure sheet 512 through the measuring hole groove 57 connected to the inner side of the test groove 56. The touch-pressure sheet 512 is pressed by the air pressure to slide down the test end shell 58 to contact the energized contact. The plate 510 is pressed and the small spring is pressed, so that the buzzer 59 on the unit small plate 511 is in working state, and the alarm is used to prompt that there is a safety hazard of sealing in the connection structure at that place. The alarm only indicates the sealing problem, so as to facilitate the subsequent inspection and maintenance. At the same time, the rubber ring in the rubber ring groove 54 is tested by passing gas to see if there is a gap, so as to test the sealing of the structure connection during installation or subsequent maintenance work, so as to avoid the pressure loss of the structure sealing leading to the flow control valve end 4 connected to the structure out of control or the pressure reduction affecting normal use. In addition, the support frame 1 and the support plate 2 play a supporting role for the flow control valve end 4 installed on both sides of the casing structure 3, so as to avoid the flow control valve end 4 affecting the sealing between the casing structure 3 under the action of gravity, and facilitate the installation of the flow control valve end 4, so as to facilitate the alignment of the bolts; When testing is required, gas is introduced through the vent pipe 64, and the gas passes through the vent pipe 64 and the switching valve 63 into the inside of the diverter spacer 62. The gas passes through the upper through pipe 67 and the connecting pipe 53 connected to the side of the diverter spacer 62. When the valve body in the switching valve 63 is in a normal state without rotation, the vent pipe 64 and the diverter spacer 62 are in a connected state. At this time, the valve body in the switching valve 63 blocks the upper flow pipe 65. When the valve body in the switching valve 63 rotates, the valve body blocks the vent pipe 64, so that the flow pipe 65 is connected to the The lower flow dividing spacer 62 is in a connected state. When maintenance is required, the liquid flowing out of the sleeve structure 3 enters the liquid through hole 32 through the drainage ring 31 and enters the inner groove 33, and then enters the connector 69 through the booster pipe 68 connected to the inner groove 33. The pressure-bearing slider 610 in the connector 69 moves downward under the pressure of the liquid and pushes the connected top plug 612. As the pressure-bearing slider 610 moves downward, the connector 69 is in a connected state with the top of the top plug 612. At this time, the liquid in the booster pipe 68 is connected. The plug 612 enters the top of the pressure cylinder 66 through the connector 69. At this time, the liquid on the top plug piece 612 enters the top of the bottom plug piece 613 through the connecting hole. Then, the liquid between the bottom plug piece 613 and the top plug piece 612 increases, and the bottom plug piece 613 slides down to push the pressure spring to compress. After the pressure spring is compressed, it pushes the extrusion plug piece 614 to apply pressure. At this time, the extrusion plug piece 614 squeezes the sealing grease inside the pressure cylinder 66 through the connected flow tube 65 to enter the output end shell 61, and then fills the gap in the rubber ring groove 54 through the upper through pipe 67 and the connecting pipe 53 connected to the output end shell 61. The rubber ring groove 54 is filled around to prevent the aging rubber in the rubber ring groove 54 from hardening and affecting the sealing of the connection. The hydraulic pressure formed by the flowing liquid in the sleeve structure 3 is used to store elastic force for the pressure spring, so that the extrusion plug piece 614 can squeeze the sealing grease in the pressure cylinder 66 to maintain long-term operation without additional drive, and can automatically replenish after a gap is generated in the rubber ring groove 54, thereby improving the sealing of the structural connection and reducing the risk of leakage due to aging of the sealing ring. When it is necessary to pass the pressurized liquid into the well connected to the casing structure 3, the external connecting pipe head of the fracturing pressure supply is inserted into the one-way valve end 7, and the pipe head is allowed to contact the closing cover 72 to pull the return spring. At this time, the closing cover 72 is connected with the inside of the one-way valve end 7 through the side liquid-passing groove 74 to transport the fracturing fluid. When the pressure of the reflux liquid in the well is too high through the casing structure 3, it enters the flow control valve end 4 through the casing structure 3, and the underground liquid is led out by the flow control valve end 4. When the liquid pressure in the casing structure 3 is high, the liquid flows through the connecting end 9 and the flow limiting pipe 10 into the pressure relief end 8 to impact the closing cover 72, so that the closing cover 72 is pressed and moves upward, allowing the liquid on the closing cover 72 to flow upward. The notch 74 is closed to the one-way port 71, which is convenient for the quick connection and closure of the one-way port 71, so that the closure cover 72 is automatically closed when the liquid refluxes, and then the hydraulic pressure at the top of the one-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 in the pressure relief cylinder 81, so that the pressure relief cylinder 81 drives the spring 82 to contract under the pressure of the strong spring, and then squeeze the pressure relief cylinder 81 upward to move the pressure relief hole 84 out of the installation screw 83 to relieve the pressure in the pressure relief end 8. By relieving the internal pressure of the pressure relief end 8, the internal pressure of the pressure relief end 8 is avoided to avoid excessive pressure inside the pressure relief end 8, which may cause the structure at the connection between the pressure relief end 8 and the one-way valve end 7 to collapse, thereby relieving the drainage pressure in the flow control valve end 4.

[0022] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A large diameter fracturing wellhead, comprising a support frame (1), characterized in that: The support frame (1), the bottom end of the support frame (1) is fixedly connected to a support plate (2), a sleeve structure (3) is arranged on the inner side of the middle part of the support frame (1), flow control valve ends (4) for controlling liquid flux are installed on both sides of the sleeve structure (3), a testing mechanism (5) is connected between adjacent flow control valve ends (4), and a sealing mechanism (6) is arranged on the rear side of the support frame (1); The test mechanism (5) comprises a sealing port (51), deep annular grooves (52) are provided on both sides of the sealing port (51), a connecting pipe (53) is fixedly connected to the outer surface of the sealing port (51), a rubber ring groove (54) is provided near the center of the side of the sealing port (51), a branch groove (55) is provided on the side wall of the rubber ring groove (54), a test slot (56) is fixedly connected to the bottom end of the rubber ring groove (54), a measuring hole groove (57) is provided on the inner wall of the test slot (56), a touch-pressure sheet (512) is provided below the measuring hole groove (57), an energized contact sheet (510) is provided below the touch-pressure sheet (512), a unit small plate (511) is fixedly connected to the bottom end of the energized contact sheet (510), a buzzer (59) is installed above the unit small plate (511), and a test end shell (58) is slidably connected to the outer side of the touch-pressure sheet (512).

2. The large diameter fracturing wellhead according to claim 1, characterized in that: 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) via a branch groove (55); the measuring hole groove (57) penetrates 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 small plate (511); a small spring is provided on the top surface of the T-shaped block; and two ends of the small spring are respectively fixedly connected to the T-shaped block and the contact pressure sheet (512); the test end shell (58) is fixedly connected to the sealing port (51); the measuring hole groove (57) penetrates from the test groove (56) to the inside of the test end shell (58) and has a side cross-sectional shape of an "eight" through distribution.

3. The large diameter fracturing wellhead according to claim 2, characterized in that: The sealing mechanism (6) comprises an output end shell (61), the inner bottom surface of the output end shell (61) is fixedly connected to a flow dividing spacer (62), the bottom surface of the output end shell (61) is fixedly connected to an upper through pipe (67), a top cover is arranged above the flow dividing spacer (62), and a switching valve (63) is fixedly connected above the top cover, the top end of the switching valve (63) is fixedly connected to a flow pipe (65), the side of the switching valve (63) is fixedly connected to a ventilation pipe (64), the top end of the flow pipe (65) is fixedly connected to a pressure tube (66), and the top end of the pressure tube (66) is fixedly connected to a connector (69).

4. The large diameter fracturing wellhead according to claim 3, characterized in that: The inner wall of the connecting head (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 piece (612) is fixedly connected to the bottom surface of the pressure-bearing slider (610), a bottom plug piece (613) is arranged below the top plug piece (612), and an extrusion plug piece (614) is arranged below the bottom plug piece (613), and a boost pipe (68) is fixedly connected to the top end of the connecting head (69).

5. The large diameter fracturing wellhead according to claim 4, characterized in that: The switching valve (63) is connected to the inside of the flow dividing spacer (62) through the top cover; an inclined slice is provided on the top side of the pressure-bearing sliding block (610); a branch pipe extending outward is provided on the side of the upper through 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 respectively fixedly connected to the extrusion plug (614) and the bottom plug (613).

6. The large diameter fracturing wellhead according to claim 5, characterized in that: The sleeve structure (3) comprises a drainage ring (31), the drainage ring (31) being fixedly connected to the inner wall of the sleeve structure (3), a lower inner groove (33) being provided inside the bottom end of the sleeve structure (3), a liquid through hole (32) being provided on the inner wall of the lower inner groove (33), the liquid through hole (32) being connected to a boosting pipe (68), and the boosting pipe (68) being fixedly connected to the sleeve structure (3).

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

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

9. The large diameter fracturing wellhead according to claim 7, characterized in that: The pressure relief end (8) comprises a pressure relief cylinder (81), the outer side of the pressure relief cylinder (81) is slidably connected to a mounting screw cylinder (83), the bottom end of the pressure relief cylinder (81) is fixedly connected to a spring sheet (82), a strong spring is arranged between the spring sheet (82) and the mounting screw cylinder (83), and the two ends of the strong spring are respectively fixedly connected to the spring sheet (82) and the mounting screw cylinder (83), an inner cavity (85) is arranged inside the pressure relief cylinder (81), 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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