Ground control device for a rodless plunger drainage and gas extraction pump

Abstract

A ground control device for a rodless plunger drainage and air-collecting pump. The invention comprises an inlet pipeline connecting a water tank to the inlet of the injection pump; a downstream return pipeline connected at one end to the water tank and at the other end to the upstream pipeline; one end of the upstream pipeline connected to the outlet of the injection pump; an electromagnetic directional valve installed on both the downstream and upstream pipelines; a pressure relief pipeline connecting the water tank to the outlet of the injection pump. Its advantages include a simple and reasonable structure; the use of a PLC to control the pump's operating speed, the opening and closing sequence of the directional valves, and the opening and closing time to achieve the reciprocating motion of the rodless plunger drainage and air-collecting pump; effectively reducing the failure rate of the control device and improving the operating efficiency of the rodless plunger drainage and air-collecting pump.

Description

Technical Field

[0001] This invention relates to a rodless plunger drainage gas extraction pump, and more particularly to a ground control device for the rodless plunger drainage gas extraction pump, belonging to the field of coalbed methane and shale gas development technology. Background Technology

[0002] Coalbed methane and shale gas wells are mostly highly deviated and horizontal wells. Using a rodless plunger drainage gas pump for rodless drainage operations can effectively solve problems such as sucker rod breakage and tubing leakage caused by rod wear in rod-operated drainage processes, providing a new technology for drainage in highly deviated and horizontal wells. The applicant has previously applied for an invention patent for a rodless plunger drainage gas pump (application number: 202111401957.3), which will not be elaborated upon here.

[0003] Currently, most ground control devices for rodless plunger drainage and gas extraction pumps employ hydraulically controlled directional valves to control the alternating injection of power hydraulic fluid into the pump's upward and downward movement, driving the plunger to reciprocate. When high-pressure water flows through the hydraulically controlled directional valve's inner cavity, it inevitably interferes with the hydraulic oil in the hydraulic cylinder. Long-term operation can lead to emulsification and deterioration of the hydraulic oil, resulting in a series of adverse consequences. These side effects are mainly fourfold: First, water dilutes the hydraulic oil, damaging the oil film strength, reducing the lubrication performance of the hydraulic oil, and accelerating the wear of components within the hydraulic system; second, water causes corrosion on the surfaces of metal components within the hydraulic system, increasing leakage when the piston applies pressure in the hydraulic cavity, reducing working efficiency, and increasing solid metal contaminants within the system; third, water accelerates the oxidation of the hydraulic oil, causing valve core sticking and preventing the hydraulic system from functioning properly; fourth, after emulsification, the anti-foaming properties of the hydraulic oil decrease, and the large amount of foam generated during energy transmission can cause cavitation in the hydraulic system, increasing system vibration and noise, while also accelerating the oxidation and deterioration of the hydraulic oil.

[0004] Coalbed methane wells typically range in depth from 600 to 1500 meters, while shale gas wells generally range from 3500 to 5000 meters. According to the requirements of the gas well drainage system, the operating range of the rodless plunger drainage gas production pump is 0.5 to 3 times per minute. If calculated at 1.5 times per minute, the switching frequency of the reversing valve would be 2160 times per day. The well depth, bottom hole pressure, and the number of operating strokes directly determine the upward pressure of the plunger in the rodless plunger drainage gas production pump. Based on the field conditions of coalbed methane wells, this pressure varies from 7 to 15 MPa, and is even higher in shale gas wells. When the reversing valve switches directions, the fluid velocity in the pipeline changes drastically, generating a huge hydraulic shock, causing significant noise and vibration. High-frequency, high-pressure reversing can easily lead to leakage at pipeline connections, shortening the lifespan of the reversing control relay, causing the return spring inside the reversing valve to break, the push rod to deform, and damage to hydraulic components and sealing devices, ultimately resulting in frequent equipment failures and a high failure rate.

[0005] The produced water is mostly high in mineral content and salinity, and also contains coal dust, impurities, fracturing quartz sand, and other sediments. Some of it also has an odor and is corrosive. During long-term operation of the equipment, these impurities can cause poor sealing between the valve core and valve seat in the reversing valve, resulting in leakage in severe cases and affecting the normal operation of the rodless plunger drainage and gas production pump. Summary of the Invention

[0006] In order to overcome the above-mentioned shortcomings of existing rodless plunger drainage gas pump control devices, the present invention provides a ground control device for rodless plunger drainage gas pump.

[0007] The technical solution adopted by the present invention to solve its technical problem is: a ground control device for a rodless plunger drainage and gas extraction pump, including a water tank, a rodless plunger drainage and gas extraction pump, a reversing valve, a pressure gauge, and a PLC programmable logic controller. The water tank is equipped with an overflow pipe and a drain pipe. The PLC controls the operation of the ground control device. The ground control device also includes an inlet pipeline, a downflow return pipeline, an upflow return pipeline, a pressure relief pipeline, and a water injection pump.

[0008] The water inlet pipeline connects the water tank to the water inlet of the water injection pump.

[0009] One end of the downflow return water pipeline is connected to the water tank, and the other end is connected to the upflow pipeline; one end of the upflow pipeline is connected to the outlet I of the water injection pump; an electromagnetic reversing valve I is installed on the downflow return water pipeline, and an electromagnetic reversing valve II is installed on the upflow pipeline.

[0010] One end of the upward return water pipeline is connected to the water tank, and the other end is connected to the downward pipeline; one end of the downward pipeline is connected to the outlet II of the water injection pump; an electromagnetic reversing valve III is installed on the upward return water pipeline, and an electromagnetic reversing valve IV is installed on the downward pipeline.

[0011] One end of the pressure relief pipeline is connected to the water tank, and the other end is connected to the outlet I or outlet II of the water injection pump.

[0012] The annular space formed by the upward pipeline and the central pipe of the rodless plunger drainage gas pump is connected to the oil pipe; the downward pipeline is connected to the central pipe of the rodless plunger drainage gas pump.

[0013] Furthermore, the pressure relief pipeline includes pressure relief pipeline I and pressure relief pipeline II. Pressure relief pipeline I is equipped with a mechanical pressure relief valve, and pressure relief pipeline II is equipped with an electromagnetic pressure relief valve.

[0014] Furthermore, the solenoid directional valve I, solenoid directional valve II, solenoid directional valve III, solenoid directional valve IV, and solenoid pressure relief valve are two-position two-way solenoid valves; the solenoid directional valve I, solenoid directional valve II, solenoid directional valve III, and solenoid directional valve IV are pilot-operated normally open solenoid valves, and the solenoid pressure relief valve is a pilot-operated normally closed solenoid valve.

[0015] The water tank is equipped with a water tank filter that divides the water tank into left and right parts; filters are also installed in the water inlet pipeline, the upstream pipeline, and the downstream pipeline.

[0016] When the plunger of the rodless plunger drainage and gas extraction pump moves upward, water in the water tank enters the inlet of the water injection pump through the inlet pipeline. Electromagnetic directional valves I and IV are energized and closed, while electromagnetic directional valves II and III are de-energized and opened, forming an upward passage for the plunger.

[0017] When the plunger of the rodless plunger drainage and gas extraction pump moves downward, water in the water tank enters the inlet of the water injection pump through the inlet pipeline. Electromagnetic reversing valves II and III are energized and closed, while electromagnetic reversing valves I and IV are de-energized and opened, forming a downward plunger path.

[0018] When the pipeline of the control device is blocked or the rodless plunger drainage gas pump malfunctions, the PLC controls the opening of the pressure relief channel, the electromagnetic pressure relief valve is energized and opens, and the electromagnetic reversing valves I, II, III, and IV are de-energized and open. High-pressure water flows back to the water tank through the downflow return water pipeline, pressure relief pipeline II, and upflow return water pipeline.

[0019] When one or more of the electromagnetic pressure relief valve and electromagnetic directional valve I, electromagnetic directional valve II, electromagnetic directional valve III, and electromagnetic directional valve IV fail, and the pipeline pressure exceeds the predetermined pressure value of the mechanical pressure relief valve, the pressure relief pipeline I is opened, and the high-pressure water flows back to the water tank through the pressure relief pipeline I.

[0020] A ground control device for a rodless plunger drainage and gas extraction pump includes a water tank, a rodless plunger drainage and gas extraction pump, a reversing valve, a pressure gauge, and a PLC programmable logic controller. The water tank is equipped with an overflow pipe and a drain pipe. The operation of the ground control device is controlled by the PLC. The device also includes an inlet pipeline, a downflow return pipeline, an upflow return pipeline, a pressure relief pipeline, and a water injection pump. The inlet pipeline connects the water tank to the inlet of the water injection pump. One end of the downflow return pipeline is connected to the water tank, and the other end is connected to the upflow pipeline. One end of the upflow pipeline is connected to the outlet B of the water injection pump. An electromagnetic reversing valve I is installed on the downflow return pipeline, and an electromagnetic reversing valve II is installed on the upflow pipeline. One end of the upflow return pipeline is connected to the water tank, and the other end is connected to the downflow pipeline. One end of the downflow pipeline is connected to the outlet B of the water injection pump. An electromagnetic reversing valve III is installed on the upflow return pipeline, and an electromagnetic reversing valve IV is installed on the downflow pipeline. One end of the pressure relief pipeline is connected to the water tank, and the other end is connected to the outlet B of the water injection pump. The annular space formed by the upward pipeline, the central pipe of the rodless plunger drainage and gas extraction pump, and the oil pipe is connected; the downward pipeline is connected to the central pipe of the rodless plunger drainage and gas extraction pump.

[0021] A ground control device for a rodless plunger drainage and gas extraction pump includes a water tank, a rodless plunger drainage and gas extraction pump, a reversing valve, a pressure gauge, and a PLC programmable logic controller. The water tank is equipped with an overflow pipe and a drain pipe. The operation of the ground control device is controlled by the PLC. It also includes an inlet pipeline, a downflow return pipeline A, an upflow return pipeline A, and a pressure relief pipeline.

[0022] The water inlet pipeline connects the water tank to the water inlet of the water injection pump.

[0023] One end of the upstream pipeline A is connected to the outlet I, and the other end is connected to the ground pipeline. An electromagnetic reversing valve IIA is installed on the upstream pipeline A. One end of the downstream return pipeline A is connected to the electromagnetic reversing valve IIA, and the other end is connected to the water tank.

[0024] One end of the downflow pipeline A is connected to the outlet II, and the other end is connected to the ground pipeline. The downflow pipeline A is equipped with a solenoid reversing valve IVA. One end of the upflow return pipeline A is connected to the solenoid reversing valve IVA, and the other end is connected to the water tank.

[0025] One end of the pressure relief pipeline is connected to the water tank, and the other end is connected to the outlet I or outlet II of the water injection pump.

[0026] The annular space formed by the upward pipeline A and the central pipe of the rodless plunger drainage gas pump and the oil pipe is connected; the downward pipeline A and the central pipe of the rodless plunger drainage gas pump are connected.

[0027] The beneficial effects of this invention are that it has a simple and reasonable structure. By using PLC to control the operating speed of the water injection pump and the opening and closing sequence and time of the reversing valve, the up-and-down reciprocating motion of the rodless plunger drainage and gas extraction pump can be realized. This effectively reduces the failure rate of the control device, improves the operating efficiency and stability of the rodless plunger drainage and gas extraction pump, and extends the service life of the gas extraction pump. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the ground control device for the rodless plunger drainage and gas extraction pump of the present invention.

[0029] Figure 2 It is attached Figure 1 A schematic diagram of the uplink control in an embodiment.

[0030] Figure 3 It is attached Figure 1 A schematic diagram of downlink control in an embodiment.

[0031] Figure 4 It is attached Figure 1 A schematic diagram of overpressure protection in an embodiment.

[0032] Figure 5 This is a schematic diagram of the structure of Embodiment 2 of the present invention.

[0033] Figure 6 This is a schematic diagram of the structure of Embodiment 3 of the present invention.

[0034] In the diagram: 1. Water tank, 2. Water tank filter, 3. Filter I, 4. Filter II, 5. Filter III, 6. Solenoid directional valve I, 7. Solenoid directional valve II, 8. Solenoid directional valve III, 9. Solenoid directional valve IV, 10. Solenoid pressure relief valve, 11. Inlet water pipeline, 12. Downward return water pipeline, 13. Pressure relief pipeline I, 14. Pressure relief pipeline II, 15. Upward return water pipeline, 16. Overflow pipe, 17. Drain pipe, 18. Machine 19. Pressure gauge, 20. Water pump, 21. Upstream pipeline, 22. Downstream pipeline, 23. Outlet I, 24. Outlet II, 25. Inlet, 53. Outlet B, 60. Electromagnetic pressure relief valve A, 61. Upstream pipeline A, 62. Downstream return pipeline A, 64. Pressure relief pipeline IIA, 65. Upstream return pipeline A, 66. Downstream pipeline A, 67. Electromagnetic directional valve IIA, 69. Electromagnetic directional valve IVA. Detailed Implementation

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments. However, those skilled in the art should understand that the present invention is not limited to the specific embodiments listed, and any embodiment that conforms to the spirit of the present invention should be included within the scope of protection of the present invention.

[0036] In the description of this invention, it should be noted that the terms "vertical", "up", "down", "left", "right", "horizontal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0037] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," "join," and "seal" should be interpreted broadly. For example, a 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; it can be a connection between the internal parts of two components. A seal can be an oil seal, a packing seal, or other sealing forms. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0038] Appendix Figures 1-4 This is a schematic diagram of Embodiment 1 of the present invention.

[0039] See appendix Figure 1The present invention discloses a ground control device for a rodless plunger drainage and gas extraction pump, comprising a water tank 1, a reversing valve, a pressure gauge 19, and a PLC programmable logic controller (not shown in the figure, and the specific control program is not included in the protection content of the present invention). The water tank 1 is equipped with an overflow pipe 16 and a drain pipe 17. The operation of the ground control device is controlled by the PLC.

[0040] The ground control device also includes a water inlet pipeline 11, a downward return water pipeline 12 for the rodless plunger drainage and gas extraction pump (not shown in the figure) when the plunger is moving downward, an upward return water pipeline 15 for the rodless plunger drainage and gas extraction pump when the plunger is moving upward, and a pressure relief pipeline when the ground control device malfunctions.

[0041] One end of the water inlet pipeline 11 is connected to the water tank 1, and the other end is connected to the water inlet 25 of the water injection pump 20.

[0042] One end of the downflow return water pipeline 12 is connected to the water tank 1, and the other end is connected to the upflow pipeline 21; one end of the upflow pipeline 21 is connected to the outlet I23 of the water injection pump 20, and the other end is connected to the annular space formed by the central pipe and oil pipe of the rodless plunger drainage gas pump (not shown in the figure); an electromagnetic reversing valve I6 is installed on the downflow return water pipeline 12, and an electromagnetic reversing valve II7 is installed on the upflow pipeline 21.

[0043] One end of the upward return water pipeline 15 is connected to the water tank 1, and the other end is connected to the downward pipeline 22; one end of the downward pipeline 22 is connected to the outlet II 24 of the water injection pump 20, and the other end is connected to the central pipe of the rodless plunger drainage and air extraction pump (not shown in the figure); an electromagnetic reversing valve III 8 is installed on the upward return water pipeline 15, and an electromagnetic reversing valve IV 9 is installed on the downward pipeline 22.

[0044] One end of the pressure relief pipeline is connected to the water tank 1, and the other end is connected to the outlet I 23 or outlet II 24 of the water injection pump 20.

[0045] Furthermore, the pressure relief pipeline includes pressure relief pipeline I 13 and pressure relief pipeline II 14. Pressure relief pipeline I 13 is equipped with a mechanical pressure relief valve 18, and pressure relief pipeline II 14 is equipped with an electromagnetic pressure relief valve 10. The pressure gauge 19 is installed at outlet I 23 and / or outlet II 24.

[0046] Furthermore, the electromagnetic directional valve I6, electromagnetic directional valve II7, electromagnetic directional valve III8, electromagnetic directional valve IV9, and electromagnetic pressure relief valve 10 are two-position two-way electromagnetic valves.

[0047] Furthermore, the solenoid directional valve I6, solenoid directional valve II7, solenoid directional valve III8, and solenoid directional valve IV9 are pilot-operated normally open solenoid valves, and the solenoid pressure relief valve 10 is a pilot-operated normally closed solenoid valve.

[0048] The water tank 1 is equipped with a water tank filter 2, which divides the water tank 1 into left and right parts. The inlet pipe 11, the downstream return pipe 12, and the pressure relief pipe I 13 are connected to the left part of the water tank 1; the upstream return pipe 15, the pressure relief pipe II 14, the overflow pipe 16, and the drain pipe 17 are connected to the right part of the water tank 1. The inlet pipe 11 is equipped with filter I 3, the upstream pipe 21 is equipped with filter II 4, and the downstream pipe 22 is equipped with filter III 5. The installation of the above filters can effectively remove impurities from the water and purify the water quality.

[0049] See appendix Figure 2 When the plunger of the rodless plunger drainage and gas extraction pump moves upward, the PLC controls the solenoid directional valve to switch to upward mode. Water in water tank 1 enters the inlet 25 of water injection pump 20 through inlet pipeline 11. Solenoid directional valve I6 and solenoid directional valve IV9 are energized and closed, while solenoid directional valve II7 and solenoid directional valve III8 are de-energized and opened, forming an upward passage for the plunger.

[0050] The water entering the injection pump 20 is pressurized to become high-pressure power fluid. The high-pressure power fluid passes through the electromagnetic reversing valve II7, filter II4, and the upward pipeline 21, surface pipeline, and underground pipeline in sequence, and is injected into the annular space formed by the central pipe and the oil pipe of the rodless plunger drainage gas pump. This pushes the plunger in the gas pump upward to complete the extraction of formation water downhole, and lifts the mixture in the upper chamber of the gas pump (i.e., the mixture of injected water and formation water) to the surface through the central pipe. Afterward, the mixture passes through the downward pipeline 22 and is filtered by filter III5, and then enters the right side of the water tank 1 through the electromagnetic reversing valve III8 and the upward return water pipeline 15. Excess produced fluid is discharged to the surface water pool through the overflow water pipe 16.

[0051] See appendix Figure 3 When the plunger of the rodless plunger drainage and gas extraction pump is lowered, the PLC controls the solenoid directional valve to switch to the downward mode. Water in water tank 1 enters the inlet 25 of water injection pump 20 through water inlet pipeline 11. Solenoid directional valves II 7 and III 8 are energized and closed, while solenoid directional valves I 6 and IV 9 are de-energized and opened, forming the downward passage of the plunger.

[0052] The water entering the injection pump 20 is pressurized to become high-pressure kinetic fluid. This high-pressure kinetic fluid passes through the solenoid directional valve IV9, filter III5, downlink pipeline 22, surface pipeline, and underground tubing, and is injected into the central pipe of the rodless plunger drainage gas extraction pump. This pushes the plunger of the gas extraction pump downwards to reset, and the liquid inside the pump chamber enters the central pipe to form a mixture with the kinetic fluid. As the pump barrel descends, it compresses the water within its space, causing a small amount to overflow from the annular space formed by the central pipe and the oil pipe. This overflow water passes through the uplink pipeline 21 and is filtered by filter II4, then flows through the solenoid directional valve I6 and the downlink return water pipeline 12 into the left side of the water tank 1.

[0053] See appendix Figure 4When the pipeline of the control device becomes blocked or the rodless plunger drainage gas pump malfunctions, the system pressure of the control device increases, the PLC control program opens the pressure relief channel, the electromagnetic pressure relief valve 10 is energized and opens, and the electromagnetic reversing valves I6, II7, III8, and IV9 are de-energized and open. The high-pressure water flows back to the water tank 1 through the downflow return water pipeline 12, the pressure relief pipeline II14, and the upflow return water pipeline 15.

[0054] When one or more of the electromagnetic pressure relief valve 10, electromagnetic directional valve I6, electromagnetic directional valve II7, electromagnetic directional valve III8, and electromagnetic directional valve IV9 fail to open or close normally, and the pipeline pressure exceeds the predetermined pressure value of the mechanical pressure relief valve 18, the pressure relief pipeline I13 is opened, and the high-pressure water flows back to the water tank 1 through the pressure relief pipeline I13.

[0055] Example 2:

[0056] See appendix Figure 5 A ground control device for a rodless plunger drainage and gas extraction pump includes a water tank 1, a reversing valve, a pressure gauge 19, and a PLC programmable logic controller. The water tank 1 is equipped with an overflow pipe 16 and a drain pipe 17. The operation of the ground control device is controlled by the PLC.

[0057] The ground control device also includes an inlet water pipeline 11, a downflow return water pipeline 12, an upflow return water pipeline 15, and a pressure relief pipeline.

[0058] One end of the water inlet pipeline 11 is connected to the water tank 1, and the other end is connected to the water inlet 25 of the water injection pump 20.

[0059] One end of the downflow return water pipeline 12 is connected to the water tank 1, and the other end is connected to the upflow pipeline 21. One end of the upflow pipeline 21 is connected to the outlet B53 of the water injection pump 20, and the other end is connected to the ground pipeline. A solenoid reversing valve I6 is installed on the downflow return water pipeline 12, and a solenoid reversing valve II7 is installed on the upflow pipeline 21.

[0060] One end of the upward return water pipeline 15 is connected to the water tank 1, and the other end is connected to the downward pipeline 22; one end of the downward pipeline 22 is connected to the outlet B53 of the water injection pump; an electromagnetic reversing valve III8 is installed on the upward return water pipeline 15, and an electromagnetic reversing valve IV9 is installed on the downward pipeline 22.

[0061] One end of the pressure relief pipeline is connected to the water tank 1, and the other end is connected to the outlet B53 of the water injection pump 20. The specific structure of the pressure relief pipeline in Example 2 is the same as that in Example 1.

[0062] The annular space formed by the upward pipeline and the central pipe of the rodless plunger drainage gas pump is connected to the oil pipe; the downward pipeline is connected to the central pipe of the rodless plunger drainage gas pump.

[0063] The working process of Example 2 is basically the same as that of Example 1, and will not be described again.

[0064] Example 3:

[0065] See appendix Figure 6 A ground control device for a rodless plunger drainage and gas extraction pump includes a water tank 1, a reversing valve, a pressure gauge 19, and a PLC programmable logic controller. The water tank 1 is equipped with an overflow pipe 16 and a drain pipe 17. The operation of the ground control device is controlled by the PLC.

[0066] The ground control device also includes an inlet water pipeline 11, a downflow return water pipeline A62, an upflow return water pipeline A65, and a pressure relief pipeline.

[0067] One end of the water inlet pipeline 11 is connected to the water tank 1, and the other end is connected to the water inlet 25 of the water injection pump 20.

[0068] One end of the upward pipeline A61 is connected to the outlet I23, and the other end is connected to the ground pipeline. The upward pipeline A61 is equipped with an electromagnetic reversing valve IIA67. One end of the downward return pipeline A62 is connected to the electromagnetic reversing valve IIA67, and the other end is connected to the water tank 1.

[0069] One end of the downlink pipeline A66 is connected to the outlet II24, and the other end is connected to the ground pipeline. The downlink pipeline A66 is equipped with an electromagnetic reversing valve IVA69. One end of the uplink return pipeline A65 is connected to the electromagnetic reversing valve IVA69, and the other end is connected to the water tank 1.

[0070] Furthermore, the electromagnetic directional valve IIA67 and electromagnetic directional valve IVA69 are two-position three-way electromagnetic valves.

[0071] One end of the pressure relief pipeline is connected to the water tank 1, and the other end is connected to the outlet I 23 or outlet II 24 of the water injection pump 20.

[0072] Furthermore, the pressure relief pipeline includes pressure relief pipeline I13 and pressure relief pipeline IIA64. The pressure relief pipeline I13 is equipped with a mechanical pressure relief valve 18, and the pressure relief pipeline IIA64 is equipped with an electromagnetic pressure relief valve A60. The electromagnetic pressure relief valve A60 is a pilot-operated normally open electromagnetic valve, which can prevent the pump head 20 from being pressurized in the event of a sudden power failure, thus ensuring safety.

[0073] The annular space formed by the upward pipeline A61 and the central pipe of the rodless plunger drainage gas pump and the oil pipe is connected; the downward pipeline A66 is connected to the central pipe of the rodless plunger drainage gas pump.

[0074] The working process of Example 3 is as follows:

[0075] When the plunger of the rodless plunger drainage and gas extraction pump moves upward, the PLC controls the solenoid directional valve to switch to the upward mode. Water in the water tank 1 enters the inlet 25 of the water injection pump 20 through the inlet pipeline 11. The solenoid directional valve IIA67 is energized and switches to the left position, the solenoid directional valve IVA69 is de-energized and remains in the right position, and the solenoid pressure relief valve A60 is energized and closes, forming the upward passage for the plunger.

[0076] The water entering the injection pump 20 is pressurized to become high-pressure power fluid. The high-pressure power fluid passes sequentially through the left position of the electromagnetic reversing valve IIA67, filter II4, the upward pipeline A61, the surface pipeline, and the underground pipeline, and is injected into the annular space formed by the central pipe and the oil pipe of the rodless plunger drainage gas pump. This pushes the plunger in the gas pump upward, completing the extraction of formation water downhole, and lifting the mixture in the upper chamber of the gas pump (i.e., the mixture of injected water and formation water) to the surface through the central pipe. Afterward, the mixture passes through the downward pipeline A66 and is filtered by filter III5, and then enters the right side of the water tank 1 through the right position of the magnetic reversing valve IVA69 and the upward return water pipeline A65. Excess produced fluid is discharged to the surface water pool through the overflow pipe 16.

[0077] When the plunger of the rodless plunger drainage and gas extraction pump is controlled to move downward, the PLC controls the solenoid directional valve to switch to downward mode. Water in water tank 1 enters the inlet 25 of water injection pump 20 through water inlet pipeline 11. Solenoid directional valve IVA69 is energized and switched to the left position, solenoid directional valve IIA67 is de-energized and remains in the right position, and solenoid pressure relief valve A60 is energized and closed, forming the downward path of the plunger.

[0078] The water entering the injection pump 20 is pressurized into high-pressure kinetic fluid. This high-pressure kinetic fluid passes through the left position of the solenoid directional valve IVA69, filter III5, downlink pipeline A66, surface pipeline, and underground tubing, and is injected into the central pipe of the rodless plunger drainage gas pump. This pushes the plunger of the gas pump downwards to reset, and the liquid inside the pump chamber enters the central pipe to form a mixture with the kinetic fluid. As the gas pump barrel descends, it compresses the water within its space, causing a small amount to overflow from the annular space formed by the central pipe and the oil pipe. This overflow water passes through the uplink pipeline A61 and is filtered by filter II4, then through the right position of the solenoid directional valve IVA67 and the downlink return water pipeline A62 into the left side of the water tank 1.

[0079] When the pipeline of the control device is blocked or the rodless plunger drainage gas pump malfunctions, the system pressure of the control device increases, the PLC control program opens the pressure relief channel, the electromagnetic pressure relief valve A60 of the pressure relief pipeline IIA64 is de-energized and opens, and the high-pressure water flows back to the water tank 1 through the pressure relief pipeline II14.

[0080] When the electromagnetic pressure relief valve A60 fails to open and close normally, and the pipeline pressure exceeds the predetermined pressure value of the mechanical pressure relief valve 18, the pressure relief pipeline I13 is opened, and the high-pressure water flows back to the water tank 1 through the pressure relief pipeline I13.

[0081] This invention employs a PLC to control the operating speed of the water injection pump and the opening and closing sequence and timing of the reversing valve, thereby achieving the reciprocating motion of the rodless plunger drainage and air extraction pump and enabling ground-based control of its operation. The performance of the control device directly determines the operating efficiency, stability, and service life of the rodless plunger drainage and air extraction pump. By replacing the traditional hydraulic reversing mechanism with an electromagnetic valve, the invention leverages the advantages of electromagnetic valves: low reversing impact, high permissible reversing frequency, good sealing performance, corrosion resistance, strong fatigue resistance, long service life, convenient maintenance, and ease of automatic control. This effectively reduces the failure rate of the control device, improves the operating efficiency and stability of the rodless plunger drainage and air extraction pump, extends its service life, and meets the operational requirements of the rodless plunger drainage and air extraction pump. The water in the control device's tank undergoes secondary filtration before entering the inlet of the injection pump. The water in the tank is pressurized by the injection pump to form high-pressure kinetic fluid. The PLC of the control device controls the opening and closing sequence and timing of the solenoid valves, driving the high-pressure kinetic fluid to be injected alternately in a cyclical manner. This causes the high-pressure kinetic fluid to switch between the upward and downward movement of the gas pump plunger, realizing the reciprocating motion of the gas pump plunger. The produced fluid from the gas pump is lifted to the ground through the oil pipe string, filtered, and then returned to the water tank for recycling. Excess produced water is metered by a flow meter and discharged into a sump. Impurities in the water settle at the bottom of the tank and are discharged from the bottom drain during periodic cleaning.

[0082] It should be noted that the above embodiments are examples and not limitations of the present invention, and 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 ground control device for a rodless plunger drainage and air extraction pump, comprising a water tank, a rodless plunger drainage and air extraction pump, a reversing valve, a pressure gauge, and a PLC programmable logic controller, wherein the water tank is equipped with an overflow pipe and a drain pipe, and the PLC controls the operation of the ground control device, characterized in that: The ground control unit also includes an inlet water pipeline, a downflow return water pipeline, an upflow return water pipeline, a pressure relief pipeline, and a water injection pump; The water inlet pipeline connects the water tank to the water inlet of the water injection pump; One end of the downflow return water pipeline is connected to the water tank, and the other end is connected to the upflow pipeline; one end of the upflow pipeline is connected to the outlet I of the water injection pump; an electromagnetic reversing valve I is installed on the downflow return water pipeline, and an electromagnetic reversing valve II is installed on the upflow pipeline. One end of the upward return water pipeline is connected to the water tank, and the other end is connected to the downward pipeline; one end of the downward pipeline is connected to the outlet II of the water injection pump; an electromagnetic reversing valve III is installed on the upward return water pipeline, and an electromagnetic reversing valve IV is installed on the downward pipeline. One end of the pressure relief pipeline is connected to the water tank, and the other end is connected to the outlet I or outlet II of the water injection pump. The annular space formed by the upward pipeline and the central pipe of the rodless plunger drainage gas pump is connected to the oil pipe; the downward pipeline is connected to the central pipe of the rodless plunger drainage gas pump. When the plunger of the rodless plunger drainage and gas extraction pump moves upward, the water in the water tank enters the inlet of the water injection pump through the inlet pipeline. Electromagnetic reversing valve I and electromagnetic reversing valve IV are energized and closed, while electromagnetic reversing valve II and electromagnetic reversing valve III are de-energized and opened, forming an upward passage for the plunger. When the plunger of the rodless plunger drainage and gas extraction pump moves downward, water in the water tank enters the inlet of the water injection pump through the inlet pipeline. Electromagnetic reversing valves II and III are energized and closed, while electromagnetic reversing valves I and IV are de-energized and opened, forming a downward plunger path.

2. The ground control device for the rodless plunger drainage and gas extraction pump according to claim 1, characterized in that: The pressure relief pipeline includes pressure relief pipeline I and pressure relief pipeline II. Pressure relief pipeline I is equipped with a mechanical pressure relief valve, and pressure relief pipeline II is equipped with an electromagnetic pressure relief valve.

3. The ground control device for the rodless plunger drainage and gas extraction pump according to claim 2, characterized in that: The solenoid directional valve I, solenoid directional valve II, solenoid directional valve III, solenoid directional valve IV, and solenoid pressure relief valve are two-position two-way solenoid valves. The solenoid directional valves I, II, III, and IV are pilot-operated normally open solenoid valves, while the solenoid pressure relief valve is a pilot-operated normally closed solenoid valve.

4. The ground control device for the rodless plunger drainage and gas extraction pump according to claim 3, characterized in that: The water tank is equipped with a water tank filter that divides the water tank into left and right parts. Filters are installed in the inlet pipeline, the upstream pipeline, and the downstream pipeline.

5. The ground control device for the rodless plunger drainage and gas extraction pump according to claim 2, characterized in that: When the pipeline of the control device is blocked or the rodless plunger drainage gas pump malfunctions, the PLC controls the opening of the pressure relief channel, the electromagnetic pressure relief valve is energized and opens, and the electromagnetic reversing valves I, II, III, and IV are de-energized and open. High-pressure water flows back to the water tank through the downflow return water pipeline, pressure relief pipeline II, and upflow return water pipeline. When one or more of the electromagnetic pressure relief valve and electromagnetic directional valve I, electromagnetic directional valve II, electromagnetic directional valve III, and electromagnetic directional valve IV fail, and the pipeline pressure exceeds the predetermined pressure value of the mechanical pressure relief valve, the pressure relief pipeline I is opened, and the high-pressure water flows back to the water tank through the pressure relief pipeline I.

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