Multifunctional pump for coal-bed gas well

Abstract

The present application relates to coal bed gas mining technical field, especially to a kind of coal bed gas well multifunctional pump, including multifunctional pump pump cylinder, adjustable height and rotationally arranged in multifunctional pump pump cylinder mobile valve assembly and fixed valve assembly being arranged at the bottom end of multifunctional pump pump cylinder, the top of mobile valve assembly is connected to sucker rod, the top of multifunctional pump pump cylinder is connected to multifunctional pump, and fixed valve assembly is used to communicate coal bed gas well and multifunctional pump pump cylinder;The mobile valve assembly includes hollow draw tube, mobile valve cover, center nozzle and mobile valve.The present application uses sucker rod, hollow draw tube as high-pressure cleaning liquid manifold, annulus between multifunctional pump pump cylinder and hollow draw tube as cleaning liquid flow-back channel, so that cleaning liquid does not enter well, and the purpose of protecting reservoir is achieved.

Description

Technical Field

[0001] This invention relates to the field of coalbed methane extraction technology, and in particular to a multi-functional pump for coalbed methane wells. Background Technology

[0002] During coalbed methane well drainage, various factors such as coal seam geological conditions, drainage methods, and operational procedures cause changes in the coal seam and the coal and rock structure near the well bottom. This results in free coal dust and detached coal dust from the coal seam being transported to the wellbore by the fluid. Coal dust is usually dark gray granular with low hardness. Clay minerals are its main source of formation. Under the action of associated fluids in the coal seam, coal dust is easily broken and combines with coal char and other materials to form a sticky colloid—coal slime.

[0003] During the pumping process, some coal powder particles accumulate in the pump barrel, which can cause pump burial or jamming after a certain period of time, leading to frequent well shutdowns, well repairs, and well cleaning operations, which seriously affect the high and stable production of coalbed methane wells.

[0004] When a downhole pump becomes clogged, the gas well surface drainage system stops the pumping unit, relocates it to clear the wellhead, and a workover rig enters the site to retrieve the downhole tubing string, downhole pump, and downhole screen. These components are then transported back to the plant for cleaning, unclogging, and repair of the downhole pump. The downhole tubing string is then lowered back in, and production resumes. The entire pump inspection cycle is lengthy, and prolonged well closure is highly damaging to the gas well, leading to a significant reduction in production after restarting. Furthermore, this process involves numerous steps and requires substantial investment of manpower, resources, and capital. Summary of the Invention

[0005] This invention aims to at least solve one of the technical problems existing in related technologies. To this end, this invention provides a multi-functional pump for coalbed methane wells, solving the technical problems of difficulty in in-situ cleaning of downhole pumps and the difficulty in cleaning downhole pumps in the prior art. It utilizes a sucker pipe and a hollow tubing as a high-pressure cleaning fluid manifold, and the annulus between the multi-functional pump barrel and the hollow tubing serves as a cleaning fluid return channel, ensuring that the cleaning fluid does not enter the well and achieving the purpose of protecting the reservoir.

[0006] This invention provides a multi-functional pump for coalbed methane wells, including a multi-functional pump barrel, a movable valve assembly that is height adjustable and rotatably disposed within the multi-functional pump barrel, and a fixed valve assembly disposed at the bottom end of the multi-functional pump barrel. The top end of the movable valve assembly is connected to the sucker pipe, the top end of the multi-functional pump barrel is connected to an external pumping pump, and the fixed valve assembly is used to connect the coalbed methane well and the multi-functional pump barrel.

[0007] The traveling valve assembly includes a hollow tubing, a traveling valve cover, a central nozzle, and a traveling valve.

[0008] The top end of the hollow tube is connected to the oil extraction tube. The hollow tube is located inside the barrel of the multi-functional pump. A first liquid flow channel is formed inside the hollow tube. A second liquid flow channel is formed between the inner wall of the barrel of the multi-functional pump and the outer wall of the hollow tube.

[0009] The top of the floating valve cover is connected to the bottom of the hollow tube. A first channel and a liquid chamber are formed at the center of the floating valve cover. The first channel and the liquid chamber are connected. The central nozzle is slidably installed in the first channel. A conversion joint is connected to the bottom of the floating valve cover. A floating valve is provided on the top of the conversion joint. The floating valve is located in the liquid chamber. The floating valve cover has several strip-shaped holes spaced apart on the side wall corresponding to the liquid chamber. The strip-shaped holes are used to connect the liquid chamber and the second liquid flow channel.

[0010] A further improvement of the multi-functional pump for coalbed methane wells of the present invention is that an installation cavity is provided at the top center of the traveling valve cover, the installation cavity is connected to the first channel, the inner diameter of the installation cavity is larger than the inner diameter of the first channel, a central nozzle spring is provided in the installation cavity, the outer diameter of the central nozzle matches the inner diameter of the first channel, and a limiting ring is formed on the top outer wall of the central nozzle, the outer diameter of the limiting ring matches the inner diameter of the installation cavity.

[0011] A further improvement of the multi-functional pump for coalbed methane wells of the present invention is that a hollow pull tube limiting section is formed at the bottom position of the hollow pull tube, the valve cover of the traveling valve is sleeved on the hollow pull tube, and the top of the valve cover of the traveling valve abuts against the hollow pull tube limiting section.

[0012] A further improvement of the multi-functional pump for coalbed methane wells of the present invention is that the outer diameter of the movable valve cover is divided into a first valve cover section, a second valve cover section, and a third valve cover section from top to bottom. The outer diameter of the first valve cover section is smaller than that of the second valve cover section, the outer diameter of the second valve cover section is smaller than that of the third valve cover section, the outer diameter of the third valve cover section matches the inner diameter of the pump barrel of the multi-functional pump, the outer diameter of the conversion joint matches that of the third valve cover section, and a movable valve seat is provided on the top of the conversion joint to support the movable valve.

[0013] A further improvement of the multi-functional pump for coalbed methane wells of the present invention is that the central nozzle is provided with a plurality of second through holes, and the inner wall of the traveling valve cover is provided with a second channel. The second through holes are used to connect the first channel and the second channel, and the bottom end of the second channel is connected to the inside of the pump barrel of the multi-functional pump.

[0014] A further improvement of the multi-functional pump for coalbed methane wells of the present invention is that a one-way valve and a fixed valve cleaning nozzle are provided at the bottom end of the second channel.

[0015] A further improvement of the multi-functional pump for coalbed methane wells of the present invention is that the fixed valve assembly includes a fixed valve cover, a fixed valve orifice plate, a central push rod, and a fixed valve;

[0016] The fixed valve orifice plate is connected to the bottom end of the multi-functional pump cylinder, the fixed valve cover is connected to the bottom of the multi-functional pump cylinder, the central push rod is fixed to the center position of the top surface of the fixed valve orifice plate, the central push rod extends along the height direction and corresponds to the floating valve, the fixed valve orifice plate is provided with a plurality of third through holes at intervals, the third through holes are used to connect the multi-functional pump cylinder and the fixed valve cover, the fixed valve cleaning nozzle corresponds to the position of the third through holes, the bottom end of the fixed valve cover is connected to the screen pipe tail pipe assembly of the coalbed methane well, and the fixed valve is located inside the fixed valve cover.

[0017] A further improvement of the multi-functional pump for coalbed methane wells of the present invention is that the inner sidewall of the fixed valve cover forms a valve support portion for supporting the fixed valve.

[0018] A further improvement of the multi-functional pump for coalbed methane wells of the present invention is that a pump lower connector is inserted into the bottom of the fixed valve cover, the bottom of the pump lower connector is connected to the screen pipe tail pipe assembly of the coalbed methane well, and a fixed valve seat is provided at the top of the pump lower connector, with the top of the fixed valve seat abutting against the valve support.

[0019] A further improvement of the multi-functional pump for coalbed methane wells of the present invention is that the top of the hollow pull tube is inserted into the oil pumping pipe coupling, and the oil pumping pipe coupling is connected to the oil pumping pipe; the top of the multi-functional pump barrel is inserted into the pump upper connector, and the pump upper connector is connected to an external pumping pump.

[0020] This invention relates to a multi-functional pump for coalbed methane wells, designed to meet the normal production needs of coalbed methane wells while allowing cleaning of both the moving and stationary valve assemblies without moving the tubing string. The multi-functional pump enables the introduction of high-pressure fluid into the well, forming a high-pressure water jet to clean the downhole pump. This solves current problems encountered in coalbed methane well drainage processes, such as downhole pump blockage caused by coal dust settling, and the resulting production bottlenecks requiring downhole shutdowns, tubing string removal, and surface maintenance of the downhole pump.

[0021] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the multi-functional pump for coalbed methane wells provided by the present invention. Figure 1 .

[0024] Figure 2 This is a schematic diagram of the multi-functional pump for coalbed methane wells provided by the present invention. Figure 2 .

[0025] Figure 3 This is a schematic diagram of the valve cover of the traveling valve in the multi-functional pump for coalbed methane wells provided by the present invention.

[0026] Figure label:

[0027] 1. Oil suction pipe coupling; 2. Hollow pipe; 3. Pump top connector; 4. Multi-functional pump barrel; 5. Center nozzle spring; 6. Floating valve cover; 7. Center nozzle; 8. Floating valve; 9. Floating valve seat; 10. Adapter connector; 11. Check valve; 12. Fixed valve cleaning nozzle; 13. Center push rod; 14. Guide block; 15. Fixed valve orifice plate; 16. Fixed valve cover; 17. Fixed valve; 18. Fixed valve seat; 19. Pump bottom connector. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. The following embodiments are used to illustrate this invention but should not be used to limit the scope of this invention.

[0029] The following is combined with Figure 1 The present invention describes a multi-functional pump for coalbed methane wells, comprising a multi-functional pump barrel 4, a movable valve assembly that is height adjustable and rotatably disposed within the multi-functional pump barrel 4, and a fixed valve assembly disposed at the bottom end of the multi-functional pump barrel 4. The top end of the movable valve assembly is connected to the sucker pipe, the top end of the multi-functional pump barrel 4 is connected to an external pumping pump, and the fixed valve assembly is used to connect the coalbed methane well and the multi-functional pump barrel 4.

[0030] This invention relates to a multi-functional pump for coalbed methane wells, designed to meet the normal production needs of coalbed methane wells while allowing cleaning of both the moving and stationary valve assemblies without moving the tubing string. The multi-functional pump enables the introduction of high-pressure fluids into the well, forming a high-pressure water jet to clean the downhole pump.

[0031] Furthermore, such as Figure 1 , Figure 2 and Figure 3 As shown, the traveling valve assembly includes a hollow pull tube 2, a traveling valve cover 6, a central nozzle 7, and a traveling valve 8. The top end of the hollow pull tube 2 is connected to the sucker pipe. The hollow pull tube 2 is located inside the multi-functional pump barrel 4. A first liquid flow channel is formed inside the hollow pull tube 2, and a second liquid flow channel is formed between the inner wall of the multi-functional pump barrel 4 and the outer wall of the hollow pull tube 2. The top of the traveling valve cover 6 is connected to the bottom of the hollow pull tube 2. A first channel and a liquid chamber are formed at the center of the traveling valve cover 6. The first channel and the liquid chamber are connected. The central nozzle 7 is slidably installed in the first channel. A conversion joint 10 is connected to the bottom end of the traveling valve cover 6. A traveling valve 8 is provided on the top of the conversion joint 10. The traveling valve 8 is located inside the liquid chamber. Several strip-shaped holes are spaced apart on the side wall of the traveling valve cover 6 corresponding to the liquid chamber. The strip-shaped holes are used to connect the liquid chamber and the second liquid flow channel.

[0032] When the multi-functional pump in the coalbed methane well is performing coalbed methane extraction, the coal gas in the coalbed methane well pushes the fixed valve 17 and enters the pump cylinder 4 of the multi-functional pump. Then, through the third through hole of the fixed valve orifice plate 15, it pushes the floating valve 8 and enters the floating valve cover 6. Finally, it is extracted through the strip hole and the second liquid flow channel.

[0033] Furthermore, such as Figure 1 , Figure 2 and Figure 3 As shown, a mounting cavity is provided at the top center of the traveling valve cover 6. The mounting cavity is connected to the first channel. The inner diameter of the mounting cavity is larger than the inner diameter of the first channel. A central nozzle spring 5 is provided in the mounting cavity. The outer diameter of the central nozzle 7 matches the inner diameter of the first channel. A limit ring is formed on the top outer wall of the central nozzle 7. The outer diameter of the limit ring matches the inner diameter of the mounting cavity. The central nozzle spring 5 is used to provide a buffering force for the movement of the central nozzle 7, and the limit ring prevents the central nozzle 7 from detaching from the traveling valve cover 6.

[0034] Furthermore, such as Figure 1 , Figure 2 and Figure 3As shown, a limiting section is formed at the bottom of the hollow pipe 2. The traveling valve cover 6 is fitted onto the hollow pipe 2, and the top of the traveling valve cover 6 abuts against the limiting section of the hollow pipe 2, thereby improving the structural strength of the hollow pipe 2. The tight fit between the limiting section of the hollow pipe 2 and the traveling valve cover 6 effectively enhances the stability and reliability of the hollow pipe 2 and the traveling valve cover 6. In the high-intensity working environment of the multi-functional pump in the coalbed methane well, this design can prevent excessive movement of the traveling valve cover 6 in the axial direction, thereby avoiding leakage problems that may be caused by loosening or displacement, and ensuring the efficient and safe operation of the pump.

[0035] Furthermore, such as Figure 1 , Figure 2 and Figure 3 As shown, the outer diameter of the movable valve cover 6 is divided into a first valve cover section, a second valve cover section, and a third valve cover section from top to bottom. The outer diameter of the first valve cover section is smaller than that of the second valve cover section, and the outer diameter of the second valve cover section is smaller than that of the third valve cover section. The outer diameter of the third valve cover section matches the inner diameter of the multi-functional pump cylinder 4. The outer diameter of the conversion joint 10 matches the outer diameter of the third valve cover section. A movable valve seat 9 is provided on the top of the conversion joint 10 to support the movable valve 8.

[0036] Preferably, the mounting cavity corresponds to the first valve cover section, the first channel corresponds to the second valve cover section, and the liquid cavity corresponds to the third valve cover section.

[0037] Preferably, there are very small gaps between the outer wall of the third valve cover section and the inner diameter of the multi-functional pump barrel 4, as well as between the outer wall of the adapter 10 and the inner diameter of the multi-functional pump barrel 4, to ensure that the third valve cover section and the adapter 10 can move smoothly within the multi-functional pump barrel 4.

[0038] Furthermore, such as Figure 1 , Figure 2 and Figure 3 As shown, the central nozzle 7 has several second through holes, and the inner wall of the traveling valve cover 6 has a second channel. The second through holes are used to connect the first channel and the second channel. The bottom end of the second channel is connected to the inside of the multi-functional pump cylinder 4. The traveling valve cover 6 has an annular groove at the position corresponding to the top of the second channel to facilitate connection between the second through holes and the second channel.

[0039] Preferably, the central channel of the central nozzle 7 is used to connect the first liquid flow channel and the liquid chamber.

[0040] Specifically, such as Figure 1 , Figure 2 and Figure 3As shown, a one-way valve 11 and a fixed valve cleaning nozzle 12 are provided at the bottom of the second channel. The fixed valve cleaning nozzle 12 can be inserted into the third through hole of the fixed valve orifice plate 15 to clean the fixed valve 17. The bottom of the fixed valve cleaning nozzle 12 is lower than the bottom of the floating valve cover 6.

[0041] Preferably, the fixed valve cleaning nozzle 12 is connected to the adapter 10.

[0042] Furthermore, such as Figure 1 , Figure 2 and Figure 3 As shown, the fixed valve assembly includes a fixed valve cover 16, a fixed valve orifice plate 15, a central push rod 13, and a fixed valve 17. The fixed valve orifice plate 15 is connected to the bottom end of the multi-functional pump cylinder 4, the fixed valve cover 16 is connected to the bottom of the multi-functional pump cylinder 4, the central push rod 13 is fixed at the center of the top surface of the fixed valve orifice plate 15, the central push rod 13 extends along the height direction and corresponds to the floating valve 8, the fixed valve orifice plate 15 is provided with several third through holes at intervals, the third through holes are used to connect the multi-functional pump cylinder 4 and the fixed valve cover 16, the fixed valve cleaning nozzle 12 corresponds to the position of the third through hole, the bottom end of the fixed valve cover 16 is connected to the screen pipe tail pipe assembly of the coalbed methane well, and the fixed valve 17 is located inside the fixed valve cover 16.

[0043] Better, such as Figure 1 , Figure 2 and Figure 3 As shown, the inner sidewall of the fixed valve cover 16 forms a valve support portion for supporting the fixed valve 17.

[0044] Furthermore, such as Figure 1 , Figure 2 and Figure 3 As shown, a pump lower connector 19 is inserted into the bottom of the fixed valve cover 16. The bottom of the pump lower connector 19 is connected to the screen pipe tail pipe assembly of the coalbed methane well. A fixed valve seat 18 is provided on the top of the pump lower connector 19. The top of the fixed valve seat 18 abuts against the valve support.

[0045] Furthermore, such as Figure 1 , Figure 2 and Figure 3 As shown, the top of the hollow pull tube 2 is inserted into the oil extraction pipe coupling 1, and the oil extraction pipe coupling 1 is connected to the oil extraction pipe; the top of the multi-functional pump barrel 4 is inserted into the pump upper connector 3, and the pump upper connector 3 is connected to the external liquid pump.

[0046] Preferably, the second channel is provided with 3, and the fixed valve cleaning nozzle 12 is provided with 3; the third through hole of the fixed valve orifice plate 15 is a conical through hole, and the conical structure can guide, making it convenient for the fixed valve cleaning nozzle 12 to be inserted into the third through hole; 6 guide blocks 14 are evenly installed on the fixed valve orifice plate 15, and the guide blocks 14 are located between two adjacent third through holes, and the guide blocks 14 are arc-shaped.

[0047] This invention relates to a multi-functional pump for coalbed methane wells, designed to meet the normal production needs of coalbed methane wells while allowing cleaning of both the moving and stationary valve assemblies without moving the tubing string. The multi-functional pump enables the introduction of high-pressure fluid into the well, forming a high-pressure water jet to clean the downhole pump. This solves current problems encountered in coalbed methane well drainage processes, such as downhole pump blockage caused by coal dust settling, and the resulting production bottlenecks requiring downhole shutdowns, tubing string removal, and surface maintenance of the downhole pump.

[0048] Example 1, as Figure 1 As shown, clean the traveling valve assembly;

[0049] When a coalbed methane well experiences pump burial, pump jamming, or rod pump failure and shutdown, the cause is the accumulation of solid particles that bury the moving valve 8. At this time, the central nozzle 7 of the coalbed methane well multi-functional pump is in the lower position, extending from the first channel with its bottom end located in the liquid chamber. The second through hole and the second channel of the central nozzle 7 are closed. The flushing power fluid from the surface enters the first liquid flow channel of the hollow pull pipe 2, and then sprays out from the bottom nozzle of the central nozzle 7. The flushing power fluid carries coal powder to form a mixture and returns from the strip hole of the moving valve cover 6. The mixture returns to the surface through the second liquid flow channel between the hollow oil extraction pipe and the multi-functional pump cylinder 4, completing the cleaning of solid particles in the moving valve seat 9 and the moving valve cover 6.

[0050] Example 2, as Figure 2 As shown, the fixed valve assembly is being cleaned;

[0051] Coalbed methane wells experienced pump burial, pump jamming, and rod pump failure and shutdown due to the accumulation of solid particles and the burial of fixed valve 17.

[0052] The hollow pull tube 2 is lowered, the fixed valve cleaning nozzle 12 moves down, and the fixed valve cleaning nozzle 12 slides down the inclined surface of the guide block 14, causing the entire floating valve assembly and the hollow pull tube 2 to rotate. Finally, the fixed valve cleaning nozzle 12 falls smoothly into the third through hole of the fixed valve orifice plate 15; the three fixed valve cleaning nozzles 12 enter the three third through holes of the fixed valve orifice plate 15 respectively, and the remaining three third through holes of the fixed valve orifice plate 15 serve as cleaning return fluid channels; the central push rod 13 enters the hole of the conversion joint 10 and the floating valve seat 9, and then pushes the floating valve 8 upward;

[0053] The movable valve 8 blocks the nozzle of the central nozzle 7, and at the same time pushes the central nozzle 7 to move upward against the resistance of the central nozzle spring 5, so that the central nozzle 7 moves to the upper position; at this time, the bottom nozzle of the central nozzle 7 is closed, the second channel, the central channel of the central nozzle 7 and the first liquid flow channel are connected, and the ground high-pressure cleaning fluid is sprayed out from the second channel of the movable valve cover 6 through the one-way valve 11 and the fixed valve cleaning nozzle 12 to clean the fixed valve 17;

[0054] The cleaning return fluid from the fixed valve 17 is discharged from the fixed valve assembly through the third through hole on the fixed valve orifice plate 15 that is not blocked by the fixed valve cleaning nozzle 12. The cleaning return fluid continues to rise, passes through the annulus of the central push rod 13, the conversion joint 10 and the floating valve seat 9, and enters the liquid chamber of the floating valve cover 6. Then it returns from the strip hole of the floating valve cover 6. The cleaning return fluid returns to the ground through the second liquid flow channel, completing the cleaning of solid particles in the fixed valve assembly.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-functional pump for coalbed methane wells, characterized in that, The device includes a multi-functional pump barrel, a height-adjustable and rotatably disposed within the multi-functional pump barrel, and a fixed valve assembly disposed at the bottom end of the multi-functional pump barrel. The top end of the roaming valve assembly is connected to the oil sucker pipe, the top end of the multi-functional pump barrel is connected to an external liquid pump, and the fixed valve assembly is used to connect the coalbed methane well and the multi-functional pump barrel. The traveling valve assembly includes a hollow tubing, a traveling valve cover, a central nozzle, and a traveling valve. The top end of the hollow tube is connected to the oil extraction tube. The hollow tube is located inside the barrel of the multi-functional pump. A first liquid flow channel is formed inside the hollow tube. A second liquid flow channel is formed between the inner wall of the barrel of the multi-functional pump and the outer wall of the hollow tube. The top of the floating valve cover is connected to the bottom of the hollow tube. A first channel and a liquid chamber are formed at the center of the floating valve cover. The first channel and the liquid chamber are connected. The central nozzle is slidably installed in the first channel. A conversion joint is connected to the bottom of the floating valve cover. A floating valve is provided at the top of the conversion joint. The floating valve is located in the liquid chamber. The floating valve cover has several strip-shaped holes spaced apart on the side wall corresponding to the liquid chamber. The strip-shaped holes are used to connect the liquid chamber and the second liquid flow channel. The central nozzle has several second through holes, and the inner wall of the traveling valve cover has a second channel. The second through holes are used to connect the first channel and the second channel, and the bottom end of the second channel is connected to the inside of the multi-functional pump barrel. The fixed valve assembly includes a fixed valve orifice plate, a central push rod, and a fixed valve. The central push rod is fixed to the center of the top surface of the fixed valve orifice plate and extends along the height direction, corresponding to the floating valve. When cleaning the moving valve assembly, the central nozzle is in the lower position, with the central nozzle extending from the first channel and the bottom part located in the liquid chamber, and the second through hole of the central nozzle and the second channel are closed; When cleaning the fixed valve assembly, the central push rod pushes the floating valve upward, the floating valve blocks the nozzle of the central nozzle, the central nozzle moves to the upper position, and the second channel, the central channel of the central nozzle and the first liquid flow channel are connected.

2. The multi-functional pump for coalbed methane wells according to claim 1, characterized in that, The valve cover of the moving valve has a mounting cavity at its center top, which is connected to the first channel. The inner diameter of the mounting cavity is larger than that of the first channel. A central nozzle spring is installed in the mounting cavity. The outer diameter of the central nozzle matches the inner diameter of the first channel. A limiting ring is formed on the top outer wall of the central nozzle. The outer diameter of the limiting ring matches the inner diameter of the mounting cavity.

3. The multi-functional pump for coalbed methane wells according to claim 1, characterized in that, A hollow tube limiting section is formed at the bottom of the hollow tube, the valve cover of the traveling valve is sleeved on the hollow tube, and the top of the valve cover abuts against the limiting section of the hollow tube.

4. The multi-functional pump for coalbed methane wells according to claim 1, characterized in that, The outer diameter of the movable valve cover is divided into a first valve cover section, a second valve cover section, and a third valve cover section from top to bottom. The outer diameter of the first valve cover section is smaller than that of the second valve cover section, and the outer diameter of the second valve cover section is smaller than that of the third valve cover section. The outer diameter of the third valve cover section matches the inner diameter of the multi-functional pump barrel. The outer diameter of the conversion joint matches the outer diameter of the third valve cover section. A movable valve seat is provided on the top of the conversion joint to support the movable valve.

5. The multi-functional pump for coalbed methane wells according to claim 1, characterized in that, The bottom of the second channel is equipped with a one-way valve and a fixed valve cleaning nozzle.

6. The multi-functional pump for coalbed methane wells according to claim 5, characterized in that, The fixed valve assembly also includes a fixed valve cover; The fixed valve orifice plate is connected to the bottom end of the multi-functional pump cylinder, and the fixed valve cover is connected to the bottom of the multi-functional pump cylinder. The fixed valve orifice plate is provided with several third through holes spaced apart. The third through holes are used to connect the multi-functional pump cylinder and the fixed valve cover. The fixed valve cleaning nozzle corresponds to the position of the third through hole. The bottom end of the fixed valve cover is connected to the screen pipe tail pipe assembly of the coalbed methane well. The fixed valve is located inside the fixed valve cover.

7. The multi-functional pump for coalbed methane wells according to claim 6, characterized in that, The inner wall of the fixed valve cover forms a valve support portion for supporting the fixed valve.

8. The multi-functional pump for coalbed methane wells according to claim 7, characterized in that, The bottom of the fixed valve cover is provided with a pump lower connector, the bottom of which is connected to the screen pipe tail pipe assembly of the coalbed methane well, and the top of the pump lower connector is provided with a fixed valve seat, the top of which abuts against the valve support.

9. The multi-functional pump for coalbed methane wells according to claim 7, characterized in that, The top of the hollow tubing is inserted into the oil extraction pipe coupling, which is connected to the oil extraction pipe; the top of the multi-functional pump barrel is inserted into the pump connector, which is connected to an external liquid pump.

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