Coal bed gas automatic water injection well head device

Abstract

The application discloses a coal bed gas automatic water injection well mouth device and belongs to the technical field of water injection well mouth devices. The coal bed gas automatic water injection well mouth device comprises a water injection well main body and a water inlet pipe fixedly connected to the side surface of the water injection well main body, and a speed regulating assembly is movably arranged on the water inlet pipe. The water injection well mouth device is provided with the speed regulating assembly and can regulate the flow speed of liquid. When the water injection well mouth device is used, the plug assembly is floated up by the buoyancy of water, the locking tongue on the plug assembly pushes the sealing plate upwards, the drain pipe is opened, liquid can be conveniently discharged through the drain pipe, the water inlet pipe is connected with a double-suction water pump, when the water pump reversely sucks water, the liquid level in the water injection outer pipe is lowered, the height of the plug assembly is lowered, and thus segmented water injection at different heights or depths is conveniently realized. When the sealing plate moves upwards, the rack drives the gear to rotate, the drain pipe drives the crushing knife to rotate, the blocking coal powder at the outlet position of the drain pipe is conveniently crushed and stirred, and the drain pipe is dredged.

Description

Technical Field

[0001] This invention relates to the field of water injection wellhead device technology, and more specifically, to an automatic water injection wellhead device for coalbed methane. Background Technology

[0002] Coalbed methane (CBM) water injection wells are specialized water injection facilities built to improve CBM recovery rates. By injecting water into the coal seam, the moisture content of the coal body is increased, reducing its brittleness and minimizing coal dust migration during gas production. Simultaneously, the water pressure promotes methane desorption and flow into the wellbore. Water injection requires controlled pressure and flow rate to avoid damaging the coal structure or triggering water-locking effects. Its layout must be considered in conjunction with parameters such as coal seam permeability and geological structure. It is a crucial supporting project for ensuring stable gas production and improving extraction efficiency in CBM development. However, existing water injection well systems present the following problems:

[0003] For example, if the water injection point is at a fixed height, water may concentrate at a certain depth (such as injecting water only into the bottom of the coal seam), causing excessive stress on the local coal body due to the superposition of water seepage pressure and its own weight, which in turn leads to plastic deformation (such as local collapse and crack closure).

[0004] Meanwhile, the sealing layer at the water injection port (mostly a mixture of coal dust, rock debris, and residual moisture) accumulates over time, causing blockage at the outlet and hindering water from seeping into the coal seam.

[0005] In addition, different coal seams have significantly different adaptability to water flow velocity—coal seams with well-developed fractures can withstand high flow velocities, while tight coal seams require low flow velocities to avoid water lock-in. In order to solve the above problems, this application proposes an automatic water injection wellhead device for coalbed methane, which aims to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide an automatic water injection wellhead device for coalbed methane to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] An automatic water injection wellhead device for coalbed methane includes a water injection well body and a water inlet pipe fixedly connected to the side, wherein a speed regulating component is movably installed on the water inlet pipe.

[0009] A water injection outer pipe is fixedly connected to the lower part of the water injection well body, and a water injection inner pipe is fixedly connected to the inner side of the water injection outer pipe. A sealing head assembly is slidably connected to the water injection inner pipe. The sealing head assembly includes a float body one, a sealing bladder, a float body two, and a locking tongue. The sealing bladder is fixedly connected to the float body one, the float body two is fixedly connected to the sealing bladder, and the locking tongue is movably installed on the float body two.

[0010] The water injection outer pipe is movably provided with a plurality of drainage pipes, and a sealing assembly is arranged on the water injection outer pipe at a position on the side of the drainage pipes to seal the drainage pipes.

[0011] The upper end of the water injection outer pipe is fixedly connected with a height detection assembly to detect the height of the plugging head assembly.

[0012] By adopting the above technical scheme, the gas guide pipe is connected with the external inert gas pipeline system, inert gas is introduced into the water injection outer pipe, the internal pressure is increased, and the flow rate of the drainage is facilitated to be adjusted.

[0013] The plugging head assembly slides on the water injection inner pipe, and the liquid discharged from the lower end of the water injection inner pipe pushes the plugging head assembly to move upwards, and when the plugging head assembly moves to a position corresponding to the drainage groove, the sealing plate is pushed upwards by the locking tongue, so that the corresponding drainage pipe is opened, facilitating the liquid to be discharged, thereby realizing the segmented drainage at different heights.

[0014] When the plugging head assembly moves the sealing plate upwards, the drainage pipe drives the crushing knife to rotate, and the crushing knife crushes the plugging coal powder at the outlet, so that the plugging layer of the coal powder at the outlet is facilitated to be dredged.

[0015] Preferably, a plurality of drainage grooves are formed in the water injection outer pipe, the drainage pipe is rotatably connected in the drainage groove, and the sealing assembly further comprises a sealing plate, a movable rod two, a spring three, a sealing gasket and a landslide.

[0016] By adopting the above technical scheme, the sealing plate is pushed downwards by the spring three to seal one end of the drainage pipe through the sealing gasket.

[0017] Preferably, the lower end of the water injection inner pipe is fixedly connected with a limiting block one, and the plugging head assembly is located at a position above the limiting block one.

[0018] By adopting the above technical scheme, the plugging head assembly is prevented from being separated from the water injection inner pipe.

[0019] Preferably, the height detection assembly comprises a mounting bin, a laser distance sensor and a sealing plug, the mounting bin is fixedly connected to the upper position of the water injection outer pipe, the laser distance sensor is fixedly connected in the mounting bin, and the sealing plug is fixedly connected to the outlet position of the mounting bin.

[0020] By adopting the technical scheme, the laser distance sensor detects the height of the plugging head assembly.

[0021] Preferably, the speed regulating assembly comprises a stirring box, a stirring rod, stirring blades, a bearing one, a motor frame and a stepping motor, the stirring box is fixedly connected to the water inlet pipe, the stirring rod is rotatably connected to the stirring box through the bearing one, the stirring blades are fixedly connected to the stirring rod and located inside the stirring box, the motor frame is fixedly connected to the stirring box, and the stepping motor is fixedly connected to the motor frame and has an output shaft fixedly connected to an upper end of the stirring rod.

[0022] By adopting the technical scheme, the rotation of the stirring blades facilitates the inert gas to be mixed into the liquid, and the rotation of the stirring blades causes more bubbles in the liquid, so that the inert gas is introduced into the water injection outer pipe through the bubbles.

[0023] Preferably, the speed regulating assembly further comprises a gas guide pipe, an exhaust pipe and a one-way valve one, one end of the gas guide pipe penetrates into the stirring box and is fixedly connected to the exhaust pipe, the exhaust pipe is located outside the stirring blades, and the one-way valve one is movably installed at an upper position of the gas guide pipe.

[0024] By adopting the technical scheme, the one-way valve one prevents the gas from flowing back from the gas guide pipe.

[0025] Preferably, the plugging head assembly further comprises fixing nails, a locking groove, a limiting groove, connecting rods, a spring one and a locking block one, the sealing capsules are fixedly connected to the floating bodies one and two through the fixing nails, the locking groove is formed in the floating body two, the limiting groove is formed in the locking tongue, the connecting rods are fixedly connected in the locking groove, the locking block one is fixedly connected to one end of the connecting rod and movably installed in the limiting groove.

[0026] By adopting the technical scheme, the sealing capsules have cavities at positions where the fixing nails, the receiving tubes and the movable rods one are located.

[0027] Preferably, the plugging head assembly further comprises a drag plate and an anti-skid pad, the drag plate is movably installed inside the limiting groove, the anti-skid pad is fixedly connected to a middle position of the drag plate, the anti-skid pad is located between the connecting rods, and the anti-skid pad is slidably connected to the locking tongue.

[0028] By adopting the technical scheme, when the anti-skid pad contacts the locking tongue, the friction is enhanced.

[0029] Preferably, the sealing head assembly further comprises a receiving tube, a movable rod one, a lock block two and a spring two, the receiving tube is fixedly connected to the float one, and the receiving tube penetrates the sealing bag upwards, the movable rod one is movably installed in the receiving tube, the lower end of the movable rod one is fixedly connected with the lock block two, and the spring two is movably installed in the receiving tube and located below the lock block two, the upper end of the movable rod one penetrates the sealing bag into the limiting groove, and the upper end of the movable rod one is fixedly connected with the drag plate.

[0030] By adopting the above technical scheme, the movable rod one is convenient to move up and down, and the sealing bag can be extruded outward.

[0031] Preferably, the dredging assembly comprises a bearing two, a crushing knife, a gear and a rack, the drain pipe is rotatably connected with the drain groove through the bearing two, the crushing knife and the gear are fixedly connected at both ends of the drain pipe respectively, the bearing two is located between the crushing knife and the gear, the rack is fixedly connected to one side of the sealing plate, and the rack is rotatably connected with the gear.

[0032] By adopting the above technical scheme, the upward and downward movement of the sealing plate can drive the crushing knife to rotate and stir the coal powder blocking layer at the outlet.

[0033] Compared with the prior art, the beneficial effects of the present application are:

[0034] 1) When the water injection wellhead device is in use, the water inlet pipe is connected with the double-suction water pump, liquid is introduced into the water injection inner pipe, the sealing head assembly is floated by the buoyancy of water, the height detection assembly detects in real time, when the sealing head assembly moves to the corresponding drain groove position, the lock tongue is inserted into the drain groove and pushes the sealing plate to rise, thereby opening the corresponding drain pipe, so that segmented water injection at different heights or depths is realized.

[0035] 2) When the water injection wellhead device is in use, the speed regulating assembly is arranged, so that a large amount of inert gas is added into the liquid, the liquid is stirred by the stirring blade to generate a large amount of bubbles containing inert gas, the bubbles and the liquid containing inert gas flow into the water injection outer pipe together, so as to change the pressure in the water injection outer pipe, and the flow rate of the drainage is convenient to change.

[0036] 3) When the water injection wellhead device is in use, when the sealing plate moves up and down, the rack drives the gear to rotate, so that the crushing knife is convenient to rotate and stir the coal powder blocking layer at the outlet, and the liquid contains a large amount of gas, so that the gas and the liquid enter the gap of the stirred coal powder, and the blocking layer at the drain pipe is convenient to dredge. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 It is a whole structure schematic view of the present application;

[0038] Figure 2 Structure diagram of the outer injection pipe of the application;

[0039] Figure 3 Structure diagram of the outer injection pipe of the application; Figure 2 Enlarged view of B in the middle;

[0040] Figure 4 Structure diagram of the outer injection pipe of the application; Figure 2 Enlarged view of A in the middle;

[0041] Figure 5 Structure diagram of the sealing assembly and the dredging assembly of the application;

[0042] Figure 6 Sectional view of the speed regulating assembly of the application;

[0043] Figure 7 Sectional view of the plugging head assembly of the application;

[0044] Figure 8 Sectional view of the lock tongue of the application;

[0045] Figure 9 Sectional view of the storage pipe of the application.

[0046] Explanation of the reference numerals in the drawings: 1, main body of the injection well; 101, water inlet pipe; 2, speed regulating assembly; 201, stirring box; 202, stirring rod; 203, stirring blade; 204, bearing one; 205, motor frame; 206, stepping motor; 207, air guide pipe; 208, exhaust pipe; 209, one-way valve one; 3, outer injection pipe; 301, drainage groove; 302, drainage pipe; 4, inner injection pipe; 401, limiting block one; 5, plugging head assembly; 501, float one; 502, sealing bag; 503, float two; 504, fixing nail; 505, lock slot; 506, lock tongue; 507, limiting slot; 508, connecting rod; 509, spring one; 510, lock block one; 511, drag plate; 512, non-slip pad; 513, storage pipe; 514, movable rod one; 515, lock block two; 516, spring two; 6, sealing assembly; 601, sealing plate; 602, movable rod two; 603, spring three; 604, sealing pad; 605, landslide; 7, dredging assembly; 701, bearing two; 702, crushing knife; 703, gear; 704, rack; 8, height detection assembly; 801, mounting bin; 802, laser distance sensor; 803, sealing plug. DETAILED DESCRIPTION

[0047] Example one, please refer to Figure 1 , Figure 2 , Figure 3 and Figure 6The utility model provides a kind of coal bed gas automatic water injection well mouth device, including water injection well main body 1 and the lateral fixed connection of water inlet pipe 101, water inlet pipe 101 is connected with the double-suction pump of outside, double-suction pump can both be into liquid in water inlet pipe 101, also can extract liquid by water inlet pipe 101, speed regulating assembly 2 is movably installed on water inlet pipe 101;

[0048] Water injection well main body 1 is fixedly connected with water injection outer pipe 3 below, water injection inner pipe 4 is fixedly connected to the inner side of water injection outer pipe 3, and the lower end of water injection inner pipe 4 is suspended above the bottom surface of water injection outer pipe 3, a plurality of drain pipes 302 are movably installed on water injection outer pipe 3, so as to facilitate the discharge of liquid through the drain pipe 302.

[0049] Speed regulating assembly 2 includes stirring box 201, stirring rod 202, stirring blade 203, bearing one 204, motor bracket 205 and step motor 206, stirring box 201 is fixedly connected to water inlet pipe 101, stirring rod 202 is rotatably connected with stirring box 201 through bearing one 204, the lower end of stirring rod 202 extends into stirring box 201, the upper end of stirring rod 202 extends to the outside position of stirring box 201, stirring blade 203 is fixedly connected to stirring rod 202, and stirring blade 203 is located at the inner side position of stirring box 201, so that stirring blade 203 can stir the liquid in stirring box 201, motor bracket 205 is fixedly connected to stirring box 201, step motor 206 is fixedly connected to motor bracket 205, and the output shaft of step motor 206 is fixedly connected with the upper end of stirring rod 202, so that step motor 206 can drive stirring blade 203 to rotate.

[0050] Speed regulating assembly 2 also includes air guide pipe 207, exhaust pipe 208 and one-way valve one 209, one end of air guide pipe 207 penetrates into stirring box 201, and is fixedly connected with exhaust pipe 208, the two end outlets of exhaust pipe 208 are located at the two side positions of stirring blade 203, so as to facilitate the upward discharge of gas from the bottom position, exhaust pipe 208 is located at the outer side position of stirring blade 203, one-way valve one 209 is movably installed on the upper position of air guide pipe 207, to avoid liquid backflow.

[0051] The utility model uses steps: when the present water injection well mouth device is used, the double-suction pump passes into the liquid outside into water injection well main body 1, and enters water injection outer pipe 3, then is discharged through corresponding drain pipe 302;

[0052] The outer end of the gas guide pipe 207 is connected to an external inert gas pipeline, allowing inert gas to enter the gas guide pipe 207 and be introduced into the liquid through the exhaust pipe 208. The stepper motor 206 is started, driving the stirring rod 202 and stirring blade 203 to rotate. The stirring blade 203 stirs the liquid, making it easier for the introduced gas to integrate into the liquid. The stirring blade 203 stirs the liquid, thereby creating a large number of bubbles. These bubbles containing inert gas enter the main body 1 of the water injection well along with the liquid, and then enter the outer water injection pipe 3, increasing the internal pressure and making the liquid discharged from the drain pipe 302 flow faster, thereby adaptively adjusting the liquid flow rate.

[0053] Example 2, please refer to Figures 1 to 9 The difference from Embodiment 1 is that a sealing head assembly 5 is slidably connected to the water injection inner pipe 4. The sealing head assembly 5 includes a float 1 501, a sealing bladder 502, a float 2 503, and a locking tongue 506. The sealing bladder 502 is fixedly connected to the float 1 501, and the float 2 503 is fixedly connected to the sealing bladder 502. The sealing bladder 502 is made of materials such as rubber and is made of solid rubber. The locking tongue 506 is movably installed on the float 2 503 and can extend and retract on the float 2 503.

[0054] A sealing component 6 is provided on the side of the drain pipe 302 on the water injection pipe 3 to seal the drain pipe 302, so that liquid cannot be discharged through the drain pipe 302.

[0055] The upper end of the water injection pipe 3 is fixedly connected to a height detection component 8 to detect the height of the sealing head component 5. Several drain pipes 302 are installed on the water injection pipe 3, and the drain pipes 302 are located at a set height. The height of the sealing head component 5 is detected by the height detection component 8.

[0056] The water injection outer pipe 3 is provided with a plurality of drainage grooves 301, and a drainage pipe 302 is rotatably connected in the drainage groove 301. The drainage pipe 302 is located on the side wall of the drainage groove 301. The sealing assembly 6 further comprises a sealing plate 601, a movable rod two 602, a spring three 603, a sealing gasket 604, and a landslide 605. The movable rod two 602 is fixedly connected to the inner side of the drainage groove 301. The upper end and the lower end of the movable rod two 602 are fixedly connected to the upper wall and the bottom wall of the drainage groove 301. The sealing plate 601 is slidably connected to the movable rod two 602. The spring three 603 is movably installed on the movable rod two 602, and the spring three 603 is located above the sealing plate 601. The spring three 603 pushes the sealing plate 601 to move downward, so that the sealing plate 601 is located below the movable rod two 602. The sealing gasket 604 is fixedly connected to the side of the sealing plate 601, and is located between the drainage pipe 302 and the sealing plate 601. The landslide 605 is fixedly connected to the upper part of the sealing plate 601. When the landslide 605 contacts the lock tongue 506, the lock tongue 506 is easily retracted inward. The sealing plate 601 is sealingly connected to one end of the drainage pipe 302 through the sealing gasket 604.

[0057] The lower end of the water injection inner pipe 4 is fixedly connected to a limiting block one 401. The plugging head assembly 5 is located above the limiting block one 401. The limiting block one 401 prevents the plugging head assembly 5 from falling off the water injection inner pipe 4.

[0058] The height detection assembly 8 comprises a mounting bin 801, a laser distance sensor 802, and a sealing plug 803. The mounting bin 801 is fixedly connected to the upper part of the water injection outer pipe 3. The laser distance sensor 802 is fixedly connected in the mounting bin 801. The laser distance sensor 802 detects the height of the plugging head assembly 5. The sealing plug 803 is fixedly connected to the outlet of the mounting bin 801. The sealing plug 803 is convenient to install and disassemble, so that the laser distance sensor 802 is convenient to replace.

[0059] The plugging head assembly 5 further comprises a fixed nail 504, a lock groove 505, a limiting groove 507, a connecting rod 508, a spring one 509, and a lock block one 510. The sealing bag 502 is fixedly connected to the float one 501 and the float two 503 through the fixed nail 504. The sealing bag 502 is made of rubber material. The lock groove 505 is provided on the float two 503. The limiting groove 507 is provided on the lock tongue 506. The connecting rod 508 is fixedly connected in the lock groove 505. The lock block one 510 is fixedly connected to one end of the connecting rod 508. The other end of the connecting rod 508 is fixedly connected to the inner wall of the limiting groove 507. The lock block one 510 is movably installed in the limiting groove 507, so that the lock tongue 506 and the lock block one 510 at one end of the connecting rod 508 do not separate.

[0060] The plugging head assembly 5 further comprises a drag plate 511 and a non-slip pad 512, the drag plate 511 is movably arranged in the inner side of the limiting groove 507, the non-slip pad 512 is fixedly connected to the middle position of the drag plate 511, the non-slip pad 512 is located between the connecting rods 508, the non-slip pad 512 can be lifted up and down, when the non-slip pad 512 is lifted up, the non-slip pad 512 can be slidably connected with the lock tongue 506, so as to enhance the friction.

[0061] The plugging head assembly 5 further comprises a receiving tube 513, a movable rod one 514, a lock block two 515 and a spring two 516, the receiving tube 513 is fixedly connected to the float one 501, and the receiving tube 513 penetrates the sealing bag 502 upwards, the movable rod one 514 is movably arranged in the receiving tube 513, the movable rod one 514 moves up and down in the receiving tube 513, the lower end of the movable rod one 514 is fixedly connected with the lock block two 515, the spring two 516 is movably arranged in the receiving tube 513, and the spring two 516 is located below the lock block two 515, the lock block two 515 makes the movable rod one 514 not to be separated from the receiving tube 513, the upper end of the movable rod one 514 penetrates the sealing bag 502 and enters the limiting groove 507, and the upper end of the movable rod one 514 is fixedly connected with the drag plate 511.

[0062] The use steps of the present application are as follows: the water injection wellhead device, the liquid in the injection inner tube 4 is discharged into the injection outer tube 3, the liquid level in the injection outer tube 3 gradually rises, the plugging head assembly 5 is pushed to move upwards, the lock tongue 506 on the side of the plugging head assembly 5 is pressed into the lock slot 505, the spring one 509 is compressed by the moved lock tongue 506, the lock tongue 506 slides on the inner wall of the injection outer tube 3, when the rising plugging head assembly 5 moves to the position corresponding to the drainage groove 301, the lock tongue 506 enters the drainage groove 301, and the spring one 509 restores to be opened;

[0063] Then the plugging head assembly 5 continues to float upwards, the lock tongue 506 is clamped with the upper position of the sealing plate 601, so as to pull the sealing plate 601 upwards, the sealing plate 601 drives the side sealing pad 604 to move upwards, the sealing pad 604 is separated from the drain pipe 302, the sealing plate 601 moves upwards, the spring three 603 on the movable rod two 602 is compressed, so as to open the drain pipe 302, and the liquid is discharged from the drain pipe 302;

[0064] When the sealing plate 601 moves to the maximum height, the reverse pressure of the spring three 603 increases to the maximum state, so that the floating body one 501, the sealing bag 502 and the floating body two 503 stop moving, and as the liquid continues to flow in, the floating body two 503 moves upward, compresses the sealing bag 502, and part of the sealing bag 502 is pressed outward to seal with the inner wall of the water injection outer pipe 3. After the floating body one 501 floats upward, the receiving pipe 513 moves upward, so that the spring two 516 in the receiving pipe 513 is compressed, the reverse thrust generated by the spring two 516 increases, the lock block two 515 and the movable rod one 514 move upward, the upper end of the movable rod one 514 penetrates into the limiting groove 507 of the floating body two 503, pushes the drag plate 511 and the non-slip pad 512 to move upward, so that the non-slip pad 512 contacts with the lock tongue 506, thereby increasing the friction force and the inward shrinking thrust of the lock tongue 506;

[0065] After the liquid below the water injection inner pipe 4 continues to flow in, the water pressure below the floating body one 501 gradually increases, pushes the floating body one 501 upward, and as the water pressure increases, the pressure on the lock tongue 506 increases, the lock tongue 506 gradually shrinks inward, gradually extrudes and deforms the non-slip pad 512, and finally the lock tongue 506 shrinks inward into the lock groove 505, so that the stop moving state of the floating body one 501, the sealing bag 502 and the floating body two 503 is released, then the floating body one 501, the sealing bag 502 and the floating body two 503 continue to slide upward on the water injection inner pipe 4, the sealing bag 502 resets, the floating body two 503 extends outward, the spring two 516 resets, the movable rod one 514 pushes the floating body two 503 to move upward, the sealing state of the sealing bag 502 and the water injection outer pipe 3 is released, the lock tongue 506 shrinks in the lock groove 505 and continues to slide on the inner wall of the water injection outer pipe 3, and when the lock tongue 506 slides to the position of the next drainage groove 301, the lock tongue 506 extends again and enters the corresponding drainage groove 301;

[0066] When the floating body one 501, the sealing bag 502 and the floating body two 503 need to move downward, the double-suction water pump is started to suck the liquid in the opposite direction, so that the liquid in the water injection outer pipe 3 is sucked through the water injection inner pipe 4, the floating body one 501, the sealing bag 502 and the floating body two 503 slide downward under the action of gravity, the lock tongue 506 extends and is clamped into the drainage groove 301 when it encounters the corresponding drainage groove 301, and the lock tongue 506 contacts with the slide 605 on the sealing plate 601, at this time the non-slip pad 512 is separated from the lock tongue 506, so that the pressure required for the lock tongue 506 to shrink inward is reduced, therefore the lock tongue 506 is clamped into the lock groove 505 under the action of gravity, the spring one 509 on the connecting rod 508 is compressed, thereby reducing the height of the floating body one 501, the sealing bag 502 and the floating body two 503 and other structures, so as to facilitate the water injection in coal seams with different heights or depths.

[0067] Example three, please refer toFigure 1 、 Figure 2 、 Figure 3 and Figure 5 The difference between the base combined with the embodiment 2 and the embodiment 3 is that the drain pipe 302 is movably provided with the dredging assembly 7, and the dredging assembly 7 dredges the coal powder blocking layer at the outlet of the drain pipe 302.

[0068] The dredging assembly 7 comprises bearing two 701, crushing knives 702, gears 703 and a rack 704. The drain pipe 302 is rotatably connected with the drain groove 301 through the bearing two 701, so that the drain pipe 302 can rotate. The crushing knives 702 and the gears 703 are fixedly connected at two ends of the drain pipe 302 respectively. The crushing knives 702 are in contact with the coal powder, and the bearing two 701 is located between the crushing knives 702 and the gears 703. The rack 704 is fixedly connected at one side of the sealing plate 601, and the rack 704 is rotatably connected with the gears 703, so that the sealing plate 601 drives the gears 703 to rotate through the rack 704.

[0069] The use steps of the present application are as follows: when the lock tongue 506 drives the sealing plate 601 to move upwards, the rack 704 drives the gears 703 to rotate, so that the gears 703 drive the drain pipe 302 to rotate, so that the crushing knives 702 on the drain pipe 302 rotate, thereby crushing the coal powder blocking layer at the outlet of the drain pipe 302, so that the liquid in the water injection outer pipe 3 can be easily discharged through the drain pipe 302. After the coal powder at the outlet of the drain pipe 302 is crushed, the liquid and the inert gas in the liquid can easily enter the gap of the coal powder, thereby enhancing the dredging effect.

[0070] The basic principle, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only preferred examples of the present application and are not intended to limit the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A coal bed gas automatic water injection wellhead device, comprising a water injection well main body (1) and a water inlet pipe (101) fixedly connected on the side, characterized in that: The water inlet pipe (101) is movably provided with a speed regulating assembly (2); The lower part of the water injection well body (1) is fixedly connected with a water injection outer pipe (3), the inner side of the water injection outer pipe (3) is fixedly connected with a water injection inner pipe (4), the water injection inner pipe (4) is slidably connected with a plugging head assembly (5), the plugging head assembly (5) comprises a float one (501), a sealing bag (502), a float two (503) and a lock tongue (506), the sealing bag (502) is fixedly connected with the float one (501), the float two (503) is fixedly connected with the sealing bag (502), and the lock tongue (506) is movably arranged on the float two (503). A plurality of drain pipes (302) are movably arranged on the water injection outer pipe (3), a sealing assembly (6) is arranged on the water injection outer pipe (3) at the side of the drain pipe (302), the drain pipe (302) is sealed, a dredging assembly (7) is movably arranged on the drain pipe (302), and the dredging assembly (7) dredges the coal powder plugging layer at the outlet of the drain pipe (302). The upper end of the water injection outer pipe (3) is fixedly connected with a height detection assembly (8) for detecting the height of the plugging head assembly (5). A plurality of drain grooves (301) are formed in the water injection outer pipe (3), the drain pipe (302) is rotatably connected in the drain groove (301), and the sealing assembly (6) further comprises a sealing plate (601), a movable rod two (602), a spring three (603), a sealing gasket (604) and a landslide (605), the movable rod two (602) is fixedly connected to the inner side of the drain groove (301), the sealing plate (601) is slidably connected to the movable rod two (602), the spring three (603) is movably arranged on the movable rod two (602), the spring three (603) is located above the sealing plate (601), the sealing gasket (604) is fixedly connected to the side of the sealing plate (601), the landslide (605) is fixedly connected to the upper part of the sealing plate (601), and the sealing plate (601) is sealingly connected with one end of the drain pipe (302) through the sealing gasket (604). The plugging head assembly (5) further comprises a fixing nail (504), a lock groove (505), a limiting groove (507), a connecting rod (508), a spring one (509) and a lock block one (510), the sealing bag (502) is fixedly connected with the float one (501) and the float two (503) through the fixing nail (504), the lock groove (505) is formed in the float two (503), the limiting groove (507) is formed in the lock tongue (506), the connecting rod (508) is fixedly connected in the lock groove (505), the lock block one (510) is fixedly connected to one end of the connecting rod (508), and the lock block one (510) is movably arranged in the limiting groove (507).

2. The automatic coal-bed gas water injection wellhead device according to claim 1, characterized in that: The lower end of the water injection inner pipe (4) is fixedly connected with a limiting block one (401), and the plugging head assembly (5) is located above the limiting block one (401).

3. The automatic coal-bed gas water injection wellhead device according to claim 1, characterized in that: The height detection assembly (8) comprises a mounting bin (801), a laser distance sensor (802) and a sealing plug (803), the mounting bin (801) is fixedly connected to the upper position of the water injection outer pipe (3), the laser distance sensor (802) is fixedly connected in the mounting bin (801), and the sealing plug (803) is fixedly connected to the outlet position of the mounting bin (801).

4. The automatic coal-bed gas water injection wellhead device according to claim 1, characterized in that: The speed regulating assembly (2) comprises a stirring box (201), a stirring rod (202), stirring blades (203), a bearing one (204), a motor frame (205) and a stepping motor (206), the stirring box (201) is fixedly connected to the water inlet pipe (101), the stirring rod (202) is rotatably connected to the stirring box (201) through the bearing one (204), the stirring blades (203) are fixedly connected to the stirring rod (202), and the stirring blades (203) are located at the inner side position of the stirring box (201), the motor frame (205) is fixedly connected to the stirring box (201), the stepping motor (206) is fixedly connected to the motor frame (205), and the output shaft of the stepping motor (206) is fixedly connected to the upper end of the stirring rod (202).

5. The automatic coal-bed gas water injection wellhead device according to claim 4, characterized in that: The speed regulating assembly (2) further comprises an air guide pipe (207), an exhaust pipe (208) and a one-way valve one (209), one end of the air guide pipe (207) penetrates into the stirring box (201), and is fixedly connected with the exhaust pipe (208), the exhaust pipe (208) is located at the outer side position of the stirring blades (203), and the one-way valve one (209) is movably installed at the upper position of the air guide pipe (207).

6. The automatic coal-bed gas water injection wellhead device according to claim 1, characterized in that: The plugging head assembly (5) further comprises a drag plate (511) and an anti-skid pad (512), the drag plate (511) is movably installed at the inner side position of the limiting groove (507), the anti-skid pad (512) is fixedly connected to the middle position of the drag plate (511), the anti-skid pad (512) is located between the connecting rods (508), and the anti-skid pad (512) is slidably connected with the lock tongue (506).

7. The automatic coal-bed gas water injection wellhead device according to claim 6, characterized in that: The plugging head assembly (5) further comprises a receiving tube (513), a movable rod one (514), a lock block two (515) and a spring two (516), the receiving tube (513) is fixedly connected to the floating body one (501), penetrates the sealing bag (502) upward, the movable rod one (514) is movably installed in the receiving tube (513), the lower end of the movable rod one (514) is fixedly connected with the lock block two (515), the spring two (516) is movably installed in the receiving tube (513), and the spring two (516) is located below the lock block two (515), the upper end of the movable rod one (514) penetrates the sealing bag (502) into the limiting groove (507), and the upper end of the movable rod one (514) is fixedly connected with the drag plate (511).

8. The automatic coal-bed gas water injection wellhead device according to claim 1, characterized in that: The dredging assembly (7) comprises bearing two (701), crushing knives (702), gears (703) and racks (704), the drain pipe (302) is rotatably connected with the drain groove (301) through the bearing two (701), the crushing knives (702) and the gears (703) are fixedly connected at the two end positions of the drain pipe (302) respectively, and the bearing two (701) is located between the crushing knives (702) and the gears (703), the rack (704) is fixedly connected at one side of the sealing plate (601), and the rack (704) is rotatably connected with the gear (703).

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