Automatic water injection wellhead device for coal bed gas

Abstract

The invention discloses an automatic coal bed gas water injection wellhead device, and belongs to the technical field of water injection wellhead devices. An automatic water injection well head device for coal bed gas comprises a water injection well body and a water inlet pipe fixedly connected to the side face, a speed adjusting assembly is movably installed on the water inlet pipe, and the water injection well head device is provided with the speed adjusting assembly to adjust the flow speed of liquid. The water inlet pipe is connected with the double-suction type water pump, when the water pump sucks water reversely, the height of the liquid level in the water injection outer pipe is reduced, the height of the plugging head assembly is reduced, and therefore segmented water injection at different heights or depths can be achieved conveniently. And when the sealing plate moves upwards, the rack drives the gear to rotate, so that the drainage pipe drives the crushing cutter to rotate, plugging pulverized coal at an outlet of the drainage pipe is conveniently crushed, and drainage dredging is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water injection wellhead devices, in particular to an automatic water injection wellhead device for coalbed methane. BACKGROUND

[0002] A coalbed methane water injection well is a special water injection facility built to improve the recovery rate of coalbed methane. By injecting water into the coalbed, the moisture of the coal body can be increased, the brittleness of the coalbed can be reduced, and the migration of coal dust during gas production can be reduced. At the same time, the pressure of water can be used to push methane desorption and flow to the wellbore. The injection of water needs to control the pressure and flow to avoid damaging the structure of the coal body or causing water lock effect. The layout needs to be combined with parameters such as coalbed permeability and geological structure. It is an important supporting project to ensure stable gas production and improve the efficiency of coalbed methane development. The existing water injection well device has the following problems when in use: For example, the height of the water injection port is fixed, which can easily cause water to concentrate at a certain depth (such as only injecting water into the bottom of the coalbed), so that the local coal body is stressed too much due to the superposition of the water permeation pressure and the self-weight, and then plastic deformation (such as local collapse, crack closure) occurs; At the same time, the sealing layer of the water injection port (mostly a mixture of coal dust, rock debris and residual moisture) will accumulate over time, causing the outlet to be blocked and hindering water from seeping into the coalbed; In addition, different coalbeds have significant differences in water flow speed adaptability - coalbeds with developed fissures can withstand high flow speed, while dense coalbeds require low flow speed to avoid water lock. In order to solve the above problems, the present application provides an automatic water injection wellhead device for coalbed methane, which aims to solve the above problems. SUMMARY

[0003] The present application aims to provide an automatic water injection wellhead device for coalbed methane to solve the problems raised in the background art: In order to achieve the above-mentioned purpose, the present application provides the following technical scheme: An automatic water injection wellhead device for coalbed methane, comprising a water injection well main body and a water inlet pipe fixedly connected on the side surface, a speed regulating assembly is movably installed on the water inlet pipe; A water injection outer pipe is fixedly connected below the water injection well main body, 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 comprises a float one, a sealing capsule, a float two and a lock tongue, the sealing capsule is fixedly connected to the float one, the float two is fixedly connected to the sealing capsule, and the lock tongue is movably installed on the float two; A plurality of drain pipes are movably installed on the water injection outer pipe, a sealing assembly is arranged on the side surface of the water injection outer pipe at the position of the drain pipe to seal the drain pipe, and a dredging assembly is movably installed on the drain pipe to dredge the coal dust sealing layer at the outlet of the drain pipe; The upper end of the water injection pipe is fixedly connected to a height detection component to detect the height of the sealing head assembly.

[0004] By adopting the above technical solution, the gas guide pipe is connected to the external inert gas pipeline system, and the inert gas is introduced into the water injection pipe to enhance the internal pressure, making the drainage flow rate easy to adjust. The plugging head assembly slides on the water injection inner pipe. The liquid discharged from the lower end of the water injection inner pipe pushes the plugging head assembly upward. When the plugging head assembly moves to the corresponding drainage groove position, the locking tongue pushes the sealing plate upward, thereby opening the corresponding drainage pipe to facilitate the discharge of liquid, thus realizing segmented drainage at different heights. When the sealing head assembly moves the sealing plate upward, the drain pipe drives the crusher to rotate. The crusher breaks up the coal dust blocking the outlet, making it easier to clear the coal dust blocking layer at the outlet.

[0005] Preferably, the water injection pipe has several drainage grooves, and the drainage pipe is rotatably connected to the drainage grooves. The sealing assembly also includes a sealing plate, a second movable rod, a third spring, a sealing gasket, and a sliding ramp. The second movable rod is fixedly connected to the inner side of the drainage groove, the sealing plate is slidably connected to the second movable rod, the third spring is movably installed on the second movable rod and is located above the sealing plate, the sealing gasket is fixedly connected to the side of the sealing plate, and the sliding ramp is fixedly connected to the upper part of the sealing plate. The sealing plate is sealed to one end of the drainage pipe through the sealing gasket.

[0006] By adopting the above technical solution, the sealing plate moves downward under the push of spring three, sealing one end of the drain pipe through the sealing gasket.

[0007] Preferably, a limiting block is fixedly connected to the lower end of the water injection inner pipe, and the sealing head assembly is located above the limiting block.

[0008] By adopting the above technical solution, the sealing head assembly is prevented from detaching from the water injection inner pipe.

[0009] Preferably, the height detection component includes an installation chamber, a laser distance sensor, and a sealing plug. The installation chamber is fixedly connected to the upper part of the water injection pipe, the laser distance sensor is fixedly connected inside the installation chamber, and the sealing plug is fixedly connected to the outlet of the installation chamber.

[0010] By adopting the above technical solution, the laser distance sensor detects the height of the sealing head assembly.

[0011] Preferably, the speed control assembly includes a mixing tank, a mixing rod, a mixing blade, a bearing, a motor frame, and a stepper motor. The mixing tank is fixedly connected to the water inlet pipe. The mixing rod is rotatably connected to the mixing tank via the bearing. The mixing blade is fixedly connected to the mixing rod and is located inside the mixing tank. The motor frame is fixedly connected to the mixing tank. The stepper motor is fixedly connected to the motor frame, and the output shaft of the stepper motor is fixedly connected to the upper end of the mixing rod.

[0012] By adopting the above technical solution, the rotation of the stirring blades makes it easier for the introduced inert gas to be fully integrated into the liquid. Furthermore, the rotation of the stirring blades causes more bubbles to appear in the liquid, which facilitates the introduction of the inert gas into the water injection pipe through the bubbles.

[0013] Preferably, the speed regulating component further includes an air guide pipe, an exhaust pipe, and a one-way valve. One end of the air guide pipe extends into the mixing chamber and is fixedly connected to the exhaust pipe. The exhaust pipe is located on the outer side of the mixing blade, and the one-way valve is movably installed on the upper part of the air guide pipe.

[0014] By adopting the above technical solution, the one-way valve prevents gas from flowing back from the gas guide pipe.

[0015] Preferably, the sealing head assembly further includes a fixing pin, a locking groove, a limiting groove, a connecting rod, a spring, and a locking block. The sealing bladder is fixedly connected to float one and float two respectively by the fixing pin. The locking groove is formed on float two, the limiting groove is formed on the locking tongue, the connecting rod is fixedly connected in the locking groove, the locking block is fixedly connected to one end of the connecting rod, and the locking block is movably installed in the limiting groove.

[0016] By adopting the above technical solution, a cavity is provided on the sealing bag at the location where the fixing nail, the storage tube and the movable rod are located.

[0017] Preferably, the sealing head assembly further includes a sliding plate and an anti-slip pad. The sliding plate is movably installed inside the limiting groove, and the anti-slip pad is fixedly connected to the middle of the sliding plate. The anti-slip pad is located between the connecting rods and can be slidably connected to the locking tongue.

[0018] By adopting the above technical solution, the friction is enhanced when the anti-slip pad comes into contact with the locking tongue.

[0019] Preferably, the sealing head assembly further includes a receiving tube, a movable rod one, a locking block two, and a spring two. The receiving tube is fixedly connected to the float one and extends upward through the sealing bladder. The movable rod one is movably installed inside the receiving tube. The lower end of the movable rod one is fixedly connected to the locking block two. The spring two is movably installed inside the receiving tube and is located below the locking block two. The upper end of the movable rod one extends through the sealing bladder into the limiting groove and is fixedly connected to the drag plate.

[0020] By adopting the above technical solution, the movable rod can be moved up and down easily, allowing the sealing bladder to be squeezed outward.

[0021] Preferably, the unblocking assembly includes a second bearing, a breaker blade, a gear, and a rack. The drain pipe is rotatably connected to the drain trough via the second bearing. The breaker blade and the gear are fixedly connected to both ends of the drain pipe, and the second bearing is located between the breaker blade and the gear. The rack is fixedly connected to one side of the sealing plate, and the rack is rotatably connected to the gear.

[0022] By adopting the above technical solution, the up-and-down movement of the sealing plate can drive the crusher to rotate and break up the coal powder blocking layer at the outlet.

[0023] Compared with the prior art, the beneficial effects of the present invention are: 1) When using this water injection wellhead device, the inlet pipe is connected to the double-suction water pump. By introducing liquid into the water injection inner pipe, the buoyancy of the water will float the plugging head assembly. The height detection component will detect the height in real time. When the plugging head assembly moves to the corresponding drainage groove position, the locking tongue is inserted into the drainage groove and pushes the sealing plate up, thereby opening the corresponding drainage pipe, which facilitates segmented water injection at different heights or depths.

[0024] 2) When this water injection wellhead device is in use, the speed regulating component adds a large amount of inert gas to the liquid being introduced. The stirring blades stir the liquid, generating a large number of bubbles containing inert gas. The bubbles and the liquid containing inert gas flow together into the water injection outer pipe, thereby changing the pressure in the water injection outer pipe and making it easier to change the drainage flow rate.

[0025] 3) When this water injection wellhead device is in use, the rack drives the gear to rotate as the sealing plate moves up and down, which makes it easy for the crushing blade to rotate and crush the coal powder blocking layer at the outlet. In addition, the liquid contains a large amount of gas, which makes it easy for gas and liquid to enter the gaps of the crushed coal powder, making it easy to clear the blocking layer at the drain pipe. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2This is a schematic diagram of the structure of the water injection outer pipe of the present invention; Figure 3 for Figure 2 Enlarged view of point B in the middle; Figure 4 for Figure 2 Enlarged view of point A in the middle; Figure 5 This is a schematic diagram of the sealing component and the unblocking component of the present invention; Figure 6 This is a cross-sectional schematic diagram of the speed regulating component of the present invention; Figure 7 This is a cross-sectional schematic diagram of the sealing head assembly of the present invention; Figure 8 This is a cross-sectional schematic diagram of the locking tongue of the present invention; Figure 9 This is a cross-sectional schematic diagram of the storage tube of the present invention.

[0027] Explanation of the numbers in the diagram: 1. Main body of the water injection well; 101. Inlet pipe; 2. Speed ​​control assembly; 201. Mixing box; 202. Mixing rod; 203. Mixing blade; 204. Bearing 1; 205. Motor frame; 206. Stepper motor; 207. Air guide pipe; 208. Exhaust pipe; 209. One-way valve 1; 3. Outer water injection pipe; 301. Drainage trough; 302. Drainage pipe; 4. Inner water injection pipe; 401. Restriction block 1; 5. Sealing head assembly; 501. Float 1; 502. Sealing bladder; 503. Float 2; 504. Fixing nail; 505. Locking groove; 506. Locking tongue; 50 7. Limiting groove; 508. Connecting rod; 509. Spring 1; 510. Locking block 1; 511. Slide plate; 512. Anti-slip mat; 513. Storage tube; 514. Movable rod 1; 515. Locking block 2; 516. Spring 2; 6. Sealing assembly; 601. Sealing plate; 602. Movable rod 2; 603. Spring 3; 604. Sealing gasket; 605. Slide; 7. Unblocking assembly; 701. Bearing 2; 702. Breaker blade; 703. Gear; 704. Rack; 8. Height detection assembly; 801. Installation chamber; 802. Laser distance sensor; 803. Sealing plug. Detailed Implementation

[0028] Example 1, please refer to Figure 1 , Figure 2 , Figure 3 and Figure 6 An automatic water injection wellhead device for coalbed methane includes a water injection well body 1 and a water inlet pipe 101 fixedly connected to the side. The water inlet pipe 101 is connected to an external double-suction water pump. The double-suction water pump can both discharge liquid into the water inlet pipe 101 and extract liquid through the water inlet pipe 101. A speed regulating component 2 is movably installed on the water inlet pipe 101. A water injection outer pipe 3 is fixedly connected to the bottom of the main body 1 of the water injection well. A water injection inner pipe 4 is fixedly connected to the inside of the water injection outer pipe 3. The lower end of the water injection inner pipe 4 is suspended above the bottom surface of the water injection outer pipe 3. Several drain pipes 302 are movably installed on the water injection outer pipe 3 to facilitate the discharge of liquid through the drain pipes 302.

[0029] The speed control assembly 2 includes a mixing tank 201, a stirring rod 202, a stirring blade 203, a bearing 204, a motor frame 205, and a stepper motor 206. The mixing tank 201 is fixedly connected to the water inlet pipe 101. The stirring rod 202 is rotatably connected to the mixing tank 201 through the bearing 204. The lower end of the stirring rod 202 extends into the mixing tank 201, and the upper end of the stirring rod 202 extends to the outside of the mixing tank 201. The stirring blade 203 is fixedly connected to the stirring rod 202 and is located inside the mixing tank 201, so that the stirring blade 203 can easily stir the liquid in the mixing tank 201. The motor frame 205 is fixedly connected to the mixing tank 201, and the stepper motor 206 is fixedly connected to the motor frame 205. The output shaft of the stepper motor 206 is fixedly connected to the upper end of the stirring rod 202, so that the stepper motor 206 can easily drive the stirring blade 203 to rotate.

[0030] The speed control assembly 2 also includes a vent pipe 207, an exhaust pipe 208, and a one-way valve 209. One end of the vent pipe 207 penetrates into the mixing tank 201 and is fixedly connected to the exhaust pipe 208. The two outlets of the exhaust pipe 208 are located on both sides of the mixing blade 203, which facilitates the upward discharge of gas from the bottom. The exhaust pipe 208 is located on the outside of the mixing blade 203. The one-way valve 209 is movably installed on the upper part of the vent pipe 207 to prevent liquid backflow.

[0031] The steps of using this invention are as follows: When this water injection wellhead device is used, the double-suction water pump introduces external liquid into the water injection well body 1 and into the water injection outer pipe 3, and then discharges it through the corresponding drain pipe 302. 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.

[0032] Example 2, please refer to Figures 1 to 9The 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.

[0033] 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.

[0034] 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.

[0035] The water inlet pipe 3 has several drainage grooves 301. Drainage pipes 302 are rotatably connected within the drainage grooves 301 and are located on the side wall of the drainage grooves 301. The sealing assembly 6 also includes a sealing plate 601, a second movable rod 602, a third spring 603, a sealing gasket 604, and a sliding ramp 605. The second movable rod 602 is fixedly connected to the inner side of the drainage groove 301, with its upper and lower ends fixedly connected to the upper and lower walls of the drainage groove 301. The sealing plate 601 is slidably connected to the second movable rod 602, and the third spring 603 is movably mounted on the second movable rod 602. Spring 3 603 is located above sealing plate 601. Spring 3 603 pushes sealing plate 601 downward, so that sealing plate 601 is located below movable rod 2 602. Sealing gasket 604 is fixedly connected to the side of sealing plate 601. Sealing gasket 604 is located between drain pipe 302 and sealing plate 601. Slide 605 is fixedly connected to the upper part of sealing plate 601. When sliding 605 contacts locking tongue 506, locking tongue 506 can easily retract inward. Sealing plate 601 is sealed to one end of drain pipe 302 through sealing gasket 604.

[0036] The lower end of the water injection inner pipe 4 is fixedly connected to a limiting block 401, and the sealing head assembly 5 is located above the limiting block 401. The limiting block 401 prevents the sealing head assembly 5 from falling off the water injection inner pipe 4.

[0037] The height detection component 8 includes an installation chamber 801, a laser distance sensor 802, and a sealing plug 803. The installation chamber 801 is fixedly connected to the upper part of the water injection pipe 3. The laser distance sensor 802 is fixedly connected inside the installation chamber 801 and detects the height of the sealing head component 5. The sealing plug 803 is fixedly connected to the outlet of the installation chamber 801. The sealing plug 803 is easy to install and remove, making it easy to replace the laser distance sensor 802.

[0038] The sealing head assembly 5 also includes a fixing pin 504, a locking groove 505, a limiting groove 507, a connecting rod 508, a spring 509, and a locking block 510. The sealing bladder 502 is fixedly connected to the float 501 and the second float 503 respectively by the fixing pin 504. The sealing bladder 502 is made of rubber material. The locking groove 505 is opened on the second float 503, and the limiting groove 507 is opened on the locking tongue 506. The connecting rod 508 is fixedly connected in the locking groove 505. The locking block 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 locking block 510 is movably installed in the limiting groove 507 so that the locking tongue 506 and the locking block 510 at one end of the connecting rod 508 will not detach.

[0039] The sealing head assembly 5 also includes a slide plate 511 and an anti-slip pad 512. The slide plate 511 is movably installed inside the limiting groove 507. The anti-slip pad 512 is fixedly connected to the middle of the slide plate 511. The anti-slip pad 512 is located between the connecting rods 508. The anti-slip pad 512 can move up and down. When the anti-slip pad 512 rises, it can slide and connect with the locking tongue 506, thereby increasing the friction.

[0040] The sealing head assembly 5 also includes a receiving tube 513, a movable rod 514, a locking block 515, and a spring 516. The receiving tube 513 is fixedly connected to the float 501 and extends upward through the sealing bladder 502. The movable rod 514 is movably installed inside the receiving tube 513 and moves up and down within the receiving tube 513. The lower end of the movable rod 514 is fixedly connected to the locking block 515. The spring 516 is movably installed inside the receiving tube 513 and is located below the locking block 515. The locking block 515 prevents the movable rod 514 from detaching from the receiving tube 513. The upper end of the movable rod 514 extends through the sealing bladder 502 into the limiting groove 507 and is fixedly connected to the sliding plate 511.

[0041] The steps of using this invention are as follows: In this water injection wellhead device, the inner water injection pipe 4 discharges liquid into the outer water injection pipe 3. The liquid level in the outer water injection pipe 3 gradually rises, pushing the sealing head assembly 5 to move upward. The locking tongue 506 on the side of the sealing head assembly 5 is pressed into the locking groove 505. The spring 509 is compressed by the moving locking tongue 506. The locking tongue 506 slides on the inner wall of the outer water injection pipe 3. When the rising sealing head assembly 5 moves to the corresponding drainage groove 301 position, the locking tongue 506 enters the drainage groove 301, and the spring 509 returns to open. Then the sealing head assembly 5 continues to float upward, the locking tongue 506 is locked with the upper part of the sealing plate 601, thereby pulling the sealing plate 601 upward, causing the sealing plate 601 to drive the side sealing gasket 604 to move upward, the sealing gasket 604 to separate from the drain pipe 302, the sealing plate 601 moves upward on the movable rod 2 602, causing the spring 3 603 on the movable rod 2 602 to be compressed, thereby opening the drain pipe 302, so that the liquid can be discharged from the drain pipe 302; When the sealing plate 601 moves to its maximum height, as the reverse pressure of the spring 603 increases to its maximum, the float 501, the sealing bladder 502, and the float 503 stop moving. As the liquid continues to flow in, the float 503 moves upward, compressing the sealing bladder 502. Part of the sealing bladder 502 is pushed outward, thus sealing itself with the inner wall of the water injection pipe 3. After the float 501 floats upward, the receiving pipe 513 moves upward, compressing the spring 516 inside the receiving pipe 513. The reverse thrust generated by the spring 516 increases, causing the locking block 515 and the moving rod 514 to move upward. The upper end of the moving rod 514 passes through the float 503 and enters the limiting groove 507, pushing the sliding plate 511 and the anti-slip pad 512 upward, causing the anti-slip pad 512 to contact the locking tongue 506, thereby increasing the friction and increasing the inward thrust of the locking tongue 506. As the liquid continues to flow into the inner water pipe 4, the water pressure below float 501 gradually increases, pushing float 501 upwards. With the increased water pressure, the pressure on the locking tongue 506 increases, causing it to gradually retract inwards, gradually deforming the anti-slip pad 512. Finally, the locking tongue 506 retracts into the locking groove 505, releasing the stopped movement of float 501, sealing bladder 502, and float 503. Then, float 501, sealing bladder 502, and... Float 2 503 continues to slide upward on the inner water injection pipe 4, sealing bladder 502 resets, float 2 503 extends outward, spring 2 516 resets, moving rod 1 514 pushes float 2 503 upward, sealing bladder 502 and outer water injection pipe 3 are released, locking tongue 506 retracts into locking groove 505 and continues to slide on the inner wall of outer water injection pipe 3. When locking tongue 506 slides to the next drainage groove 301 position, locking tongue 506 extends again and enters the corresponding drainage groove 301. When float 1 501, sealing bladder 502, and float 2 503 need to move downwards, the double-suction water pump is started to draw liquid in the reverse direction, causing the liquid to be drawn from the water injection pipe 3 through the inner water injection pipe 4. Float 1 501, sealing bladder 502, and float 2 503 slide downwards under the action of gravity. After the locking tongue 506 encounters the corresponding drainage groove 301, the locking tongue 506 extends and gets stuck in the drainage groove 301. The locking tongue 506 comes into contact with the slip 605 on the sealing plate 601. At this time, the anti-slip pad 512 separates from the locking tongue 506, reducing the pressure required for the locking tongue 506 to retract inwards. Therefore, under the action of gravity, the locking tongue 506 gets stuck in the locking groove 505, causing the spring 1 509 on the connecting rod 508 to be compressed, thereby reducing the height of the float 1 501, sealing bladder 502, and float 2 503, etc., making it easier to inject water into coal seams of different heights or depths.

[0042] Example 3, please refer to Figure 1 , Figure 2 , Figure 3 and Figure 5 The difference from the basic embodiment 2 is that a dredging component 7 is movably installed on the drain pipe 302, and the dredging component 7 dries the coal powder blocking layer at the outlet of the drain pipe 302.

[0043] The unblocking component 7 includes a second bearing 701, a breaker 702, a gear 703, and a rack 704. The drain pipe 302 is rotatably connected to the drain trough 301 via the second bearing 701, allowing the drain pipe 302 to rotate. The breaker 702 and the gear 703 are fixedly connected to both ends of the drain pipe 302. The breaker 702 is in contact with the coal powder, and the second bearing 701 is located between the breaker 702 and the gear 703. The rack 704 is fixedly connected to one side of the sealing plate 601, and the rack 704 is rotatably connected to the gear 703, allowing the sealing plate 601 to drive the gear 703 to rotate via the rack 704.

[0044] The steps of using this invention are as follows: When the locking tongue 506 moves the sealing plate 601 upward, the rack 704 drives the gear 703 to rotate, which in turn drives the drain pipe 302 to rotate. This causes the crushing blade 702 on the drain pipe 302 to rotate, thereby breaking up the coal powder blocking layer at the outlet of the drain pipe 302. This allows the liquid in the water injection pipe 3 to be discharged through the drain pipe 302. After the coal powder at the outlet of the drain pipe 302 is broken up, the liquid and the inert gas in the liquid can easily enter the gaps in the coal powder, thereby enhancing the unblocking effect.

[0045] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. An automatic water injection wellhead device for coalbed methane, comprising a water injection well body (1) and a water inlet pipe (101) fixedly connected to its side, characterized in that: A speed regulating component (2) is movably installed on the water inlet pipe (101); A water injection outer pipe (3) is fixedly connected to the bottom of the water injection well body (1). A water injection inner pipe (4) is fixedly connected to the inner side of the water injection outer pipe (3). A sealing head assembly (5) is slidably connected to the water injection inner pipe (4). The sealing head assembly (5) includes a float (501), a sealing bladder (502), a float (503), and a locking tongue (506). The sealing bladder (502) is fixedly connected to the float (501), the float (503) is fixedly connected to the sealing bladder (502), and the locking tongue (506) is movably installed on the float (503). A plurality of drain pipes (302) are movably installed on the water injection pipe (3). 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). A dredging component (7) is movably installed on the drain pipe (302) to dredge the coal powder blocking layer at the outlet of the drain pipe (302). 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).

2. The automatic water injection wellhead device for coalbed methane according to claim 1, characterized in that: The water injection pipe (3) is provided with several drainage grooves (301). The drainage pipe (302) is rotatably connected in the drainage groove (301). The sealing assembly (6) also includes a sealing plate (601), a movable rod (602), a spring (603), a sealing gasket (604), and a slope (605). The movable rod (602) is fixedly connected to the inner side of the drainage groove (301). The sealing plate (601) is slidably connected to the movable rod (602). The spring (603) is movably installed on the movable rod (602) and is located above the sealing plate (601). The sealing gasket (604) is fixedly connected to the side of the sealing plate (601). The slope (605) is fixedly connected to the upper part of the sealing plate (601). The sealing plate (601) is sealed to one end of the drainage pipe (302) through the sealing gasket (604).

3. The automatic water injection wellhead device for coalbed methane according to claim 1, characterized in that: The lower end of the water injection inner pipe (4) is fixedly connected to a limiting block (401), and the sealing head assembly (5) is located above the limiting block (401).

4. The automatic water injection wellhead device for coalbed methane according to claim 1, characterized in that: The height detection component (8) includes an installation chamber (801), a laser distance sensor (802), and a sealing plug (803). The installation chamber (801) is fixedly connected to the upper part of the water injection pipe (3), the laser distance sensor (802) is fixedly connected inside the installation chamber (801), and the sealing plug (803) is fixedly connected to the outlet of the installation chamber (801).

5. The automatic water injection wellhead device for coalbed methane according to claim 1, characterized in that: The speed control assembly (2) includes a mixing tank (201), a stirring rod (202), a stirring blade (203), a bearing (204), a motor frame (205), and a stepper motor (206). The mixing tank (201) is fixedly connected to the water inlet pipe (101). The stirring rod (202) is rotatably connected to the mixing tank (201) through the bearing (204). The stirring blade (203) is fixedly connected to the stirring rod (202) and is located inside the mixing tank (201). The motor frame (205) is fixedly connected to the mixing tank (201). The stepper motor (206) is fixedly connected to the motor frame (205), and the output shaft of the stepper motor (206) is fixedly connected to the upper end of the stirring rod (202).

6. The automatic water injection wellhead device for coalbed methane according to claim 5, characterized in that: The speed control assembly (2) also includes an air guide pipe (207), an exhaust pipe (208), and a one-way valve (209). One end of the air guide pipe (207) penetrates into the mixing tank (201) and is fixedly connected to the exhaust pipe (208). The exhaust pipe (208) is located on the outside of the mixing blade (203). The one-way valve (209) is movably installed on the upper part of the air guide pipe (207).

7. The automatic water injection wellhead device for coalbed methane according to claim 1, characterized in that: The sealing head assembly (5) also includes a fixing pin (504), a locking groove (505), a limiting groove (507), a connecting rod (508), a spring (509), and a locking block (510). The sealing bladder (502) is fixedly connected to the float (501) and the float (503) respectively by the fixing pin (504). The locking groove (505) is opened on the float (503), the limiting groove (507) is opened on the locking tongue (506), the connecting rod (508) is fixedly connected in the locking groove (505), the locking block (510) is fixedly connected to one end of the connecting rod (508), and the locking block (510) is movably installed in the limiting groove (507).

8. The automatic water injection wellhead device for coalbed methane according to claim 1, characterized in that: The sealing head assembly (5) also includes a slide plate (511) and an anti-slip pad (512). The slide plate (511) is movably installed inside the limiting groove (507). The anti-slip pad (512) is fixedly connected to the middle position of the slide plate (511). The anti-slip pad (512) is located between the connecting rods (508). The anti-slip pad (512) can be slidably connected with the locking tongue (506).

9. The automatic water injection wellhead device for coalbed methane according to claim 8, characterized in that: The sealing head assembly (5) also includes a receiving tube (513), a movable rod (514), a locking block (515), and a spring (516). The receiving tube (513) is fixedly connected to the float (501) and extends upward through the sealing bladder (502). The movable rod (514) is movably installed inside the receiving tube (513). The lower end of the movable rod (514) is fixedly connected to the locking block (515). The spring (516) is movably installed inside the receiving tube (513) and is located below the locking block (515). The upper end of the movable rod (514) extends through the sealing bladder (502) into the limiting groove (507) and is fixedly connected to the drag plate (511).

10. The automatic water injection wellhead device for coalbed methane according to claim 2, characterized in that: The unblocking component (7) includes a second bearing (701), a breaker (702), a gear (703), and a rack (704). The drain pipe (302) is rotatably connected to the drain trough (301) via the second bearing (701). The breaker (702) and the gear (703) are fixedly connected to both ends of the drain pipe (302), and the second bearing (701) is located between the breaker (702) and the gear (703). The rack (704) is fixedly connected to one side of the sealing plate (601), and the rack (704) is rotatably connected to the gear (703).

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