A rodless plunger water drainage and air extraction pump

Abstract

A rodless plunger drainage gas pump. The upper end of the upper pump barrel assembly of the present invention is fixedly connected to the center tube, and the inner hole of the center tube is connected to the inner channel in the gas pump; the annulus between the gas pump body and the outer pump barrel is the outer channel; the upper pump barrel assembly and the lower fixed assembly are axially fixed; during the operation of the gas pump, by alternately pressurizing the inner channel or the outer channel, the upper plunger of the movable assembly reciprocates along the upper pump barrel of the upper pump barrel assembly, and the lower pump barrel fixedly installed at the lower end of the upper plunger reciprocates along the lower plunger of the lower fixed assembly, so that the volume of the working chamber between the upper plunger and the lower plunger of the gas pump changes to complete the suction and discharge of liquid. Its beneficial effects are that the structural design is reasonable and can meet the mining needs of wells with different inclinations; no sucker rod is used to avoid the occurrence of eccentric wear of the sucker rod, effectively reduce the number of pump inspection operations, and reduce maintenance costs; it can effectively reduce the occurrence of sand jams and corrosion in the gas pump, extend the pump inspection cycle, and improve production efficiency.

Description

Technical Field

[0001] The invention relates to a plunger pump, in particular to a rodless plunger water drainage and gas production pump, belonging to the technical field of coal bed methane development. Background Art

[0002] At present, the application of rod pump for drainage and gas production in coalbed methane field development is one of the most important methods of mechanical gas production. As the development of coalbed methane fields enters the mid-term stage, the number of directional wells and horizontal wells increases year by year, and even the number of 90° horizontal wells is also increasing. During the production process, rod pumps are not adaptable in high-angle wells, and failures occur frequently, such as sucker rod breakage and eccentric wear, which seriously affects coalbed methane production, increases the cost of well repair in coalbed methane development operations, and is not conducive to energy conservation and environmental protection. Summary of the invention

[0003] In order to overcome the inadaptability of existing rod pumps in coalbed methane production processes in highly deviated wells and horizontal wells, frequent breakage and eccentric wear failures of the sucker rod, which seriously affect coalbed methane production, increase the well repair costs in coalbed methane development operations, and are not conducive to energy conservation and environmental protection, the present invention provides a rodless plunger water drainage gas production pump.

[0004] The technical solution adopted by the present invention to solve its technical problems is: a rodless plunger water drainage gas pump, including an outer pump barrel, a pump barrel, a floating valve, and a fixed valve. The gas pump body located in the outer pump barrel includes an upper pump barrel assembly, a movable assembly, and a lower fixed assembly. The upper end of the upper pump barrel assembly is sealed and connected to the center tube through a dual-channel body, and the inner hole of the center tube is connected to the inner channel in the gas pump; the annulus between the gas pump body and the outer pump barrel is the outer channel.

[0005] The upper pump barrel assembly and the lower fixed assembly are axially fixed; during the operation of the air pump, by alternately applying pressure to the inner channel or the outer channel, the upper plunger of the movable assembly reciprocates along the upper pump barrel of the upper pump barrel assembly, and the lower pump barrel fixedly installed at the lower end of the upper plunger reciprocates along the lower plunger of the lower fixed assembly, so that the volume of the working chamber between the upper plunger and the lower plunger of the air pump changes to complete the suction and discharge of liquid.

[0006] A double-channel main body and a center tube sealing device are sequentially installed on the upper end of the upper pump barrel of the upper pump barrel assembly.

[0007] The self-washing well damping device, housing, traveling valve, upper plunger and lower pump barrel of the movable assembly are fixedly connected in sequence from top to bottom. The traveling valve is a spring-type strong closing structure, and the housing is provided with a radial channel.

[0008] The self-washing well shock absorbing device includes a guide sleeve, a top cap, a movable joint, and a spring. The small diameter end of the stepped shaft-shaped movable joint extends through a hole at the end of the guide sleeve and is fixedly connected to the top cap, and the other end is located above the spring in the guide sleeve; the lower end of the guide sleeve is fixedly connected to the shell, and the lower end of the spring is located in a groove at the upper end of the shell.

[0009] The lower plunger, fixed valve, pull tube and bottom coupling of the lower fixed assembly are fixedly connected in sequence from top to bottom, and the fixed valve is a spring-type strong closing structure; the bottom coupling is fixedly connected to the pull tube through an internal thread, and the bottom coupling is fixedly connected to the outer pump barrel through an external thread.

[0010] The upper end of the lower plunger is provided with an anti-gas lock lower plunger valve.

[0011] The leather cup supporting mandrel of the center tube sealing device is installed in the double-channel body, and the leather cup seat ring assembly, leather cup, and pressure cap are installed in the radial annulus between the leather cup supporting mandrel and the double-channel body from top to bottom; the upper end of the leather cup supporting mandrel is connected to the center tube through the center tube coupling.

[0012] Furthermore, the number of the leather cup seat ring assemblies is more than 2.

[0013] The beneficial effects of the present invention are that the structural design is reasonable, which completely solves the impact of sucker rod breakage and eccentric wear on coalbed methane production and can meet the mining needs of wells with different inclinations; no sucker rod is used to avoid the occurrence of eccentric wear of the sucker rod, effectively reducing the number of pump inspection operations and reducing maintenance costs; through the self-washing well function of the rodless plunger drainage gas pump, the anti-corrosion shock-absorbing device, and the valve ball and valve seat spring-type strong closing device, the occurrence of sand jam and corrosion in underground pumps can be effectively reduced, the pump inspection cycle can be extended, and production efficiency can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the rodless plunger water drainage and air production pump of the present invention.

[0015] In the figure: 1. tubing coupling, 2. reducing coupling, 3. leather cup supporting mandrel, 4. leather cup, 5. seat ring, 6. pressure cap, 7. dual-channel body, 8. dual-channel coupling, 9. outer pump barrel, 10. upper pump barrel, 11. top cap, 12. movable joint, 13. guide sleeve, 14. spring, 15. housing, 16. slot, 17. valve seat, 18. valve ball, 19. valve cover, 20. lower plunger valve, 21. upper plunger, 22. lower pump barrel, 23. inner channel, 24. lower plunger, 25. outer channel, 29. pull tube, 30. anti-collision block, 31. bottom coupling, 100. upper pump barrel assembly, 101. center pipe sealing device, 200. movable assembly, 201. self-washing well shock absorbing device, 202. floating valve, 300. lower fixed assembly, 301. fixed valve. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. However, those skilled in the art should be aware that the present invention is not limited to the specific embodiments listed, and all embodiments should be included in the protection scope of the present invention as long as they conform to the spirit of the present invention.

[0017] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by terms such as “vertical”, “up”, “down”, “left”, “right” and “horizontal” are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0018] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", "connection", and "seal" should be understood in a broad sense. For example, the connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. The seal can be an oil seal, a packing seal, or other sealing forms. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0019] See attached Figure 1 The present invention discloses a rodless plunger drainage gas pump, comprising an outer pump barrel 9, a floating valve 202, a fixed valve 301, and a pump barrel. The upper end of the outer pump barrel 9 is connected to the oil pipe through an oil pipe coupling 1. The gas pump body located in the outer pump barrel 9 comprises an upper pump barrel assembly 100, a movable assembly 200, and a lower fixed assembly 300. The upper end of the upper pump barrel assembly 100 is fixedly connected to a center pipe (not shown in the figure) through a reducer coupling 2. The inner hole of the center pipe is connected to the inner channel 23 of the gas pump; the annulus between the gas pump body and the outer pump barrel 9 is the outer channel 25.

[0020] The upper pump barrel assembly 100 and the lower fixed assembly 300 are axially fixed; during the operation of the gas pump, by alternately applying pressure to the inner channel 23 or the outer channel 25, the upper plunger 21 of the movable assembly 200 reciprocates along the upper pump barrel 10 of the upper pump barrel assembly 100, and the lower pump barrel 22 fixedly installed at the lower end of the upper plunger 21 reciprocates along the lower plunger 24 of the lower fixed assembly 300, so that the volume of the working chamber between the upper plunger 21 and the lower plunger 24 of the gas pump changes to complete the suction and discharge of liquid.

[0021] The upper end of the upper pump barrel 10 of the upper pump barrel assembly 100 is sequentially mounted with a dual-channel body 7 and a center pipe sealing device 101 , and the dual-channel body 7 is fixedly connected to the upper pump barrel 10 via a dual-channel coupling 8 .

[0022] The central tube sealing device 101 includes a leather cup supporting mandrel 3, a leather cup 4, a seat ring 5, and a pressure cap 6. The leather cup supporting mandrel 3 is installed in a dual-channel body 7. There is an annulus between the leather cup supporting mandrel 3 and the dual-channel body 7. The components of the leather cup 4 and the seat ring 5, the leather cup 4, and the pressure cap 6 are installed in the radial annulus between the leather cup supporting mandrel 3 and the dual-channel body 7 from top to bottom; the upper end of the leather cup supporting mandrel 3 is connected to the central tube through the central tube coupling 2. Preferably, the number of the leather cup 4 and the seat ring 5 components is more than 2. The connection between the central tube and the gas extraction pump adopts an inserted sealing structure design with a leather cup (made of nylon) seal, which has good sealing performance and greatly improves the reliability of the seal between the gas extraction pump and the central tube.

[0023] The movable assembly 200 includes a self-cleaning well device 201, a housing 15, a traveling valve 202, an upper plunger 21, and a lower pump barrel 22, which are fixedly connected in sequence from top to bottom. The traveling valve 202 is a spring-type strong closing structure (spring-closed valve cover); the housing 15 is provided with a radial inner channel; the lower pump barrel 21 is provided with a radial slot 16, and the radial slot 16 is close to the lower end of the lower pump barrel 21.

[0024] The self-washing well shock absorbing device 201 includes a guide sleeve 13, a top cap 11, a movable joint 12, and a spring 14. The small diameter end of the stepped shaft-shaped movable joint 12 extends through the hole at the end of the guide sleeve 13 and is fixedly connected to the top cap 11, and the other end is located above the spring 14 in the guide sleeve 13; the lower end of the guide sleeve 13 is fixedly connected to the shell 15, and the lower end of the spring 14 is located in the groove at the upper end of the shell 15.

[0025] When the output fluid contains coal powder and other impurities, the sealing surface of the valve ball and the valve seat of the floating valve 202 will be attached with more sticky impurities after long-term use, causing the floating valve 202 to be poorly sealed or even fail. During the well washing operation, it is only necessary to inject sufficient pressure into the outer channel 25 to make the movable assembly 200 run to the top dead center. At this time, the radial slot 16 at the lower end of the lower pump barrel 22 will move to the space position of the middle cavity between the movable assembly 200 and the lower fixed assembly 300, and realize the connection between the internal cavity and the outer pump barrel annulus, thereby achieving the purpose of washing the floating valve. Since the self-washing well damping device 201 is equipped with a damping spring device, when the outer channel 25 is injected with pressure to wash the well, it can effectively reduce the impact force between the upper plunger and the top of the pump.

[0026] The lower plunger 24, the fixed valve 301, the pull tube 29, and the bottom coupling 31 of the lower fixed assembly 300 are fixedly connected in sequence from top to bottom, and the fixed valve 301 is a spring-type strong closing structure; the bottom coupling 31 is fixedly connected to the pull tube 29 through an internal thread, and the bottom coupling 31 is fixedly connected to the lower end of the outer pump barrel 9 through an external thread. Preferably, an anti-collision block 30 is installed between the upper end of the bottom coupling 31 and the pull tube 29.

[0027] The floating valve 202 and the fixed valve 301 are both spring-type strong closing structures, including a valve seat, a valve cover, a valve ball, a push rod, and a spring. The valve seat is fixedly connected to the valve cover, and the valve ball sits on the valve seat. The push rod and spring arranged above the valve ball are in the valve cover.

[0028] Furthermore, a lower plunger valve 20 is installed at the upper end of the lower plunger 24. The lower plunger valve 20 is composed of a valve seat 17, a valve ball 18, and a valve cover 19, which effectively prevents the air pump from gas locking during operation.

[0029] The dual-channel main body 7 of the upper pump barrel assembly 100 of the rodless plunger drainage gas extraction pump of the present invention is connected to the upper pump barrel 10, and the upper pump barrel 10 is positively suspended. The upper pump barrel 10 and the upper plunger 21 of the movable assembly 200, the lower pump barrel 22 of the movable assembly 200 and the lower plunger 24 of the lower fixed assembly 300 form two sealed pumping systems to realize the bottom well suction process of the gas extraction pump during the upstroke and the top discharge process during the downstroke.

[0030] The working principle of the present invention is:

[0031] When pressure is injected through the outer channel 25 (the pressure of the outer channel 25 is greater than the pressure of the inner channel 23), the liquid in the outer channel 25 enters the internal annular space of the gas pump through the outer channel of the dual-channel body 7, generating an upward thrust on its movable assembly 200. The movable assembly 200 moves upward, and at this time the floating valve will be closed due to the pressure change, thereby achieving the purpose of upward drainage; at the same time, during the upward movement of the movable assembly 200, due to the increase in the volume of the working chamber and the decrease in pressure, the fixed valve of the lower fixed assembly 300 will open and complete the liquid suction process.

[0032] When pressure is injected through the inner channel 23 (the pressure of the inner channel 23 is greater than the pressure of the outer channel 25), the liquid in the inner channel 23 enters the internal space of the upper pump barrel of the gas extraction pump through the central channel of the dual-channel body 7, generating a downward thrust on its movable assembly 200, causing the movable assembly 200 to move downward; at this time, the volume of the working chamber between the movable assembly 200 and the lower fixed assembly 300 decreases, the pressure increases, and the floating valve opens, thereby achieving the discharge of the liquid from the working chamber to the internal space of the upper pump barrel.

[0033] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the claims of this patent.

Claims

1. A rodless plunger water drainage and air extraction pump, comprising an outer pump barrel, a pump barrel, a floating valve, and a fixed valve, characterized in that: The gas extraction pump body located in the outer pump barrel includes an upper pump barrel assembly, a movable assembly, and a lower fixed assembly. The upper end of the upper pump barrel assembly is sealed and connected to the central tube through a dual-channel body. The inner hole of the central tube is connected to the inner channel in the gas extraction pump. The annular space between the gas extraction pump body and the outer pump barrel is the outer channel. The upper pump barrel assembly and the lower fixed assembly are axially fixed; during the operation of the gas extraction pump, by alternately pressurizing the inner channel or the outer channel, the upper plunger of the movable assembly reciprocates along the upper pump barrel of the upper pump barrel assembly, and the lower pump barrel fixedly installed at the lower end of the upper plunger reciprocates along the lower plunger of the lower fixed assembly, so that the volume of the working chamber between the upper plunger and the lower plunger of the gas extraction pump changes to complete the suction and discharge of liquid; The self-washing well shock absorbing device, housing, traveling valve, upper plunger and lower pump barrel of the movable assembly are fixedly connected in sequence from top to bottom; The self-washing well shock absorbing device comprises a guide sleeve, a top cap, a movable joint, and a spring. The small-diameter end of the step-shaft-shaped movable joint extends through a hole at the end of the guide sleeve and is fixedly connected to the top cap, and the other end is located above the spring in the guide sleeve; the lower end of the guide sleeve is fixedly connected to the housing, and the lower end of the spring is located in a groove at the upper end of the housing; The upper end of the lower plunger is provided with an anti-gas lock lower plunger valve.

2. The rodless plunger water drainage and air production pump according to claim 1 is characterized in that: A double-channel main body and a center tube sealing device are sequentially installed on the upper end of the upper pump barrel of the upper pump barrel assembly.

3. The rodless plunger water drainage and air production pump according to claim 2 is characterized in that: The traveling valve is a spring-type strong closing structure, and the housing is provided with a radial channel.

4. The rodless plunger water drainage and air extraction pump according to claim 3 is characterized in that: The lower plunger, fixed valve, pull tube and bottom coupling of the lower fixed assembly are fixedly connected in sequence from top to bottom, and the fixed valve is a spring-type strong closing structure; the bottom coupling is fixedly connected to the pull tube through an internal thread, and the bottom coupling is fixedly connected to the outer pump barrel through an external thread.

5. The rodless plunger water drainage and air production pump according to claim 2 is characterized in that: The leather cup supporting mandrel of the center tube sealing device is installed in the double-channel body, and the leather cup seat ring assembly, leather cup, and pressure cap are installed in the radial annulus between the leather cup supporting mandrel and the double-channel body from top to bottom; the upper end of the leather cup supporting mandrel is connected to the center tube through the center tube coupling.

6. The rodless plunger water drainage and air production pump according to claim 5 is characterized in that: The number of the leather cup seat ring components is more than 2.

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