A hydraulically controlled well flushing valve and a double-pump barrel oil pump capable of flushing the well

Abstract

and a tube connecting the dischar e side of the pump with a check valve in it, and a check valve in it at the pump end. The pump ends up being used to close the valve body's outer cover so that the pump can be closed after the oil drain plug is filled in. When the pump is filled with oil, the pump ends up being used to close the valve body.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum extraction, and in particular relates to a hydraulically controlled well-flushing valve and a double-pump-barrel oil pump capable of flushing the well. Background Art

[0002] In wells with heavy oil and severe wax deposition, the inner walls of the tubing can become coated with wax after a period of production. This reduces tubing clearances, increases resistance to pump rod movement, and leads to a decrease in well production. In severe cases, it can completely block the production pathway, causing the well to shut down. For example, wax deposition significantly reduces reservoir permeability and can even create "dead oil zones," impacting recovery rates. Furthermore, wax deposition increases pumping unit loads, leading to problems such as rod breakage and wax sticking, potentially causing mechanical failure. Wax deposits between the tubing and the sucker rod increase frictional resistance, shortening equipment life.

[0003] The Chinese utility model patented "Hollow Sucker Rod Well Washing Device" (CN201507281U) requires use with a hollow polished rod and a hollow sucker rod. During use, heated well-washing fluid enters the main valve sleeve through the hollow polished rod, the hollow sucker rod, and four small holes arranged around the main valve body. It then flows through a check valve and is discharged from the main valve body's central through-hole and waist holes into the downhole tubing, thereby transferring heat energy and dissolving wax and descaling. Finally, the hollow sucker rod moves up and down, continuously discharging the well-washing fluid through the well pump, downhole tubing, wellhead assembly, and oil flowline to the surface, where it enters the surface oil transportation system. During the long-term use of this device, due to the backflow of the well washing fluid through the one-way valve, the inlet of the one-way valve faces downward and the inner diameter of the opening is small. During long-term use, solid particles in the well washing fluid will be deposited and adhered to the opening of the one-way valve between the opening of the one-way valve and the bottom surface of the valve body, causing its inlet flow channel to become smaller and smaller, and even blocking the valve port of the one-way valve in the later stage, causing the one-way valve to fail, affecting the normal operation of the sucker rod, and thus affecting the production of the oil well, causing unnecessary losses.

[0004] Therefore, how to ensure the normal use of the pumping rod during the long-term well washing process to ensure the output of the oil well is a technical problem that needs to be solved. Summary of the Invention

[0005] In view of the current situation in which the inner wall of the oil pipe is covered with wax during oil extraction and the long-term use of the existing well-washing device affects the oil well production, the present invention provides a hydraulically controlled well-washing valve and a double-pump barrel oil pump capable of washing the well. By using the designed well-washing valve in conjunction with the double-pump barrel oil pump, hot water can be directly injected into the oil pipe without operating, establishing a positive washing cycle, softening the wax and driving it out of the oil pipe, and restoring normal production. The operation is simple and convenient, and the normal operation of the pumping rod will not be affected, thereby ensuring the production of the oil well.

[0006] To achieve the above-mentioned object, the present invention solves the technical problem by adopting the following technical solution: a hydraulically controlled well flushing valve, comprising an outer cylinder with openings at both ends, wherein a piston rod is provided in the outer cylinder for reciprocating along its axis, and a well flushing channel for discharging the well flushing fluid out of the outer cylinder;

[0007] A connector is provided at one end of the outer cylinder, and a switch assembly connected to one end of the piston rod for opening and closing the well washing channel is provided in the connector. The switch assembly includes a mounting seat with openings at both ends installed in the connector, and a return spring I and a valve ball provided therein. One end of the return spring I contacts the valve ball to seal the opening at one end of the mounting seat. A return spring II contacts the mounting seat at one end of the piston rod close to the connector.

[0008] The other end of the outer cylinder is provided with a hydraulic drive assembly that acts on one end of the piston rod to activate the switch assembly. The hydraulic drive assembly includes a sleeve slidably mounted on the end of the piston rod away from the connector and an oil storage tank positioned at one end of the outer cylinder. The sleeve is connected to the outside of the oil storage tank via a return spring III. The sleeve, the piston rod and the oil storage tank form an oil storage chamber for storing a fixed volume of hydraulic oil.

[0009] The connecting head is provided with an overflow control component for allowing the well washing fluid to enter the outer cylinder to drive the hydraulic drive assembly to operate.

[0010] The outer cylinder has a plurality of drainage holes arranged along the circumferential direction at one end close to the hydraulic drive assembly. The connector, the mounting seat, the annulus of the outer cylinder and the plurality of drainage holes form the well washing channel. The reset spring I is configured as a tower spring.

[0011] The mounting seat includes a retaining ring and a valve seat positioned and installed in the connecting head. One end of the retaining ring close to the piston rod is in contact with the valve seat, and the valve seat is sealed and connected to the inner wall of the connecting head.

[0012] One end of the return spring I is fixed to one end of the retaining ring, and the other end of the return spring I presses and seals the valve ball at the port of the valve seat; one end of the return spring II abuts against the stage of the piston rod, and the other end of the return spring II abuts against the end of the valve seat away from the retaining ring.

[0013] The overflow control component includes an overflow channel arranged on the connector and an overflow valve installed therein. The retaining ring is threadedly connected to the connector, and a gap between the retaining ring and the connector is communicated with the overflow channel.

[0014] One end of the oil storage tank is open, and the open end of the oil storage tank is sealingly sleeved on an end of the sliding sleeve away from the connector.

[0015] One end of the outer wall of the sliding sleeve is connected to the inner wall of the outer cylinder in a sealing and sliding manner, the other end of the outer wall of the sliding sleeve is connected to one end of the oil storage tank in a sealing and sliding manner, and one end of the inner wall of the sliding sleeve is connected to the piston rod in a sealing and sliding manner;

[0016] A metal piston ring is installed on the outer wall of one end of the sliding sleeve, and the sliding sleeve is hard-sealed with the inner wall of the outer cylinder through the metal piston ring;

[0017] The sliding sleeve is configured as a T-shaped sleeve, the cross-sectional area of ​​the sliding sleeve at one end away from the oil storage tank is larger than the other end, and the cross-sectional area of ​​the sliding sleeve at one end close to the oil storage tank is smaller than the cross-sectional area of ​​the piston rod at one end close to the oil storage tank.

[0018] The oil storage tank includes a tank body with openings at both ends, one end of the tank body is slidably connected to one end of the sliding sleeve, and the other end of the tank body is sealed with a plug; the sliding sleeve, the piston rod, the tank body and the plug form the oil storage chamber.

[0019] A limit step I and a limit step II are sequentially provided on the inner wall of the outer cylinder in a direction away from the connector. A straightening ring fixedly connected to the piston rod is slidably connected to the inner wall of the outer cylinder. One end of the straightening ring is in contact with the limit step I. The straightening ring is circumferentially provided with a plurality of through holes for the passage of well washing fluid. The limit step II is in contact with the end of the sliding sleeve close to the connector.

[0020] The outer cylinder body includes an outer cylinder I and an outer cylinder II that are detachably connected. The outer cylinder I and the outer cylinder II are sealed together. The end of the outer cylinder I away from the outer cylinder II is sealed together with the connector. The end of the outer cylinder II away from the outer cylinder I is mounted with the oil storage tank. A plurality of drainage holes are circumferentially arranged on the outer cylinder II. The limiting step I is arranged inside the outer cylinder I, and the limiting step II is formed at the connection between the outer cylinder I and the outer cylinder II.

[0021] A double-pump barrel oil pump capable of well flushing comprises the hydraulically controlled well flushing valve and an oil pump body. The oil pump body comprises an inner barrel, an outer barrel and an oil pumping assembly arranged in the inner barrel. An annular channel is formed between the inner barrel and the outer barrel for allowing liquid to pass through. After the annular channel converges, it is connected to the hydraulically controlled well flushing valve through a tail pipe. The end of the outer barrel away from the tail pipe is connected to the oil pipe.

[0022] Compared with the existing technology, the present invention has the following advantages:

[0023] (1) The present invention designs a hydraulically controlled well-washing valve and a double-barrel oil pump capable of washing wells. The hydraulically controlled well-washing valve is used in conjunction with the double-barrel oil pump. The double-barrel structure unique to the double-barrel oil pump is utilized to directly inject well-washing fluid into the oil pipe to soften the wax in the oil pipe. The softened mixed fluid enters the outer barrel and inner barrel of the double-barrel oil pump through the oil pipe to establish a positive washing cycle. After the wax is softened, it is driven out of the oil pipe through the tail pipe and the well-washing valve in turn into the casing of the oil well. The wax can be used repeatedly without any operation. The operation is simple and convenient. Long-term well-washing operation will not affect the normal operation of the sucker rod, thereby ensuring the output of the oil well.

[0024] (2) The present invention designs a hydraulically controlled well-washing valve. Before the well-washing fluid enters the well-washing valve, a small amount of well-washing fluid first enters the overflow control component and then enters the outer cylinder of the well-washing valve through the overflow control component until the pressure is sufficient to push the sliding sleeve downward. The hydraulic oil in the oil storage tank pushes the piston rod upward. Before the valve ball is pushed open to open the well-washing channel, the well-washing fluid can fully soften the wax inside the oil pipe, thereby ensuring the well-washing effect.

[0025] After the well washing channel is opened, the mixed liquid after softening the wax can be quickly discharged from the well washing valve, ensuring the efficiency of well washing;

[0026] After the well washing is completed, the sliding sleeve returns to its position under the action of the return spring III, the piston rod returns to its position under the action of the return spring II, and the valve ball falls back to the valve seat under the action of the return spring I, closing the well washing channel and ensuring normal oil pumping. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic structural diagram of the hydraulic well flushing valve of the present invention;

[0028] Figure 2 This is a schematic diagram of the installation structure of the double-pump barrel oil well pump capable of well washing of the present invention;

[0029] The markings in the above figure are: 1. Connector, 2. Switch assembly, 21. Retaining ring, 22. Valve seat, 23. Return spring I, 24. Valve ball, 3. Rubber ring I, 4. Rubber ring II, 5. Overflow control component, 51. Overflow channel, 52. Overflow valve, 6. Return spring II, 7. Righting ring, 71. Through hole, 8. Outer cylinder I, 81. Limit step I, 82. Limit step II, 9. Rubber ring III, 10. Piston rod, 11. Outer cylinder II, 111. Drain hole, 12. Liquid Pressure drive assembly, 121. Sliding sleeve, 122. Metal piston ring, 123. Return spring III, 124. Rubber ring IV, 125. Rubber ring V, 126. Oil storage chamber, 127. Oil storage tank, 1271. Tank body, 1272. Plug, 128. Rubber ring VI, 13. Oil pipe, 14. Oil well pump body, 141. Sucker rod, 142. Plunger, 143. Inner tube, 144. Outer tube, 145. Annular channel, 15. Tail pipe, 16. Hydraulic control well flushing valve, 17. Casing. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0031] In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the present invention.

[0032] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; and direct or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0033] The present invention will be further described below with reference to the accompanying drawings. Figure 2As shown, the present invention provides a hydraulically controlled well-flushing valve and a dual-pump-barrel oil well pump capable of flushing the well. The hydraulically controlled well-flushing valve 16 is used in conjunction with the oil well pump body 14 of the dual-pump-barrel oil well pump. One end of the oil well pump body 14 is connected to the oil pipe 13, and the other end of the oil well pump body 14 is connected to the hydraulically controlled well-flushing valve 16 via a tail pipe 15. The oil well pump body 14 includes an outer barrel 144, an inner barrel 143, and an oil pumping assembly disposed within the inner barrel 143. The oil pumping assembly can be configured as a plunger 142 and a sucker rod 141. An annular channel 145 is formed between the inner barrel 143 and the outer barrel 144 for fluid flow. After confluence, the annular channel 145 is connected to the hydraulically controlled well-flushing valve 16 via the tail pipe 15. The end of the outer barrel 144 away from the tail pipe 15 is connected to the oil pipe 13. This dual-barrel oil well pump can be configured as an existing sand control oil well pump. It also utilizes a dual-barrel design. A gap is created between the outer barrel 144 and the inner barrel 143 (the pump barrel), allowing fluid to flow through and transmitting pressure to the bottom of the sand control pump body. During normal operation, a tail pipe 15 is required at the bottom, serving as a sand trap. A plug must be installed at the bottom of the tail pipe 15. The present invention incorporates a hydraulically controlled well flushing valve 16, which is installed at the bottom of the tail pipe 15 and can replace the plug. During well washing, positive pressure is applied to the oil pipe 13 through existing hydraulic equipment, and washing fluid (hot water) is directly injected into the oil pipe 13 to soften the wax in the oil pipe 13. The softened mixed liquid enters the outer cylinder 144 and the inner cylinder 143 of the double-pump barrel oil well pump through the oil pipe 13 to establish a positive washing cycle. After the wax is softened, it is driven out of the oil pipe 13 through the tail pipe 15 and the hydraulically controlled well washing valve 16 into the oil well casing 17. No operation is required and it can be used repeatedly. The operation is simple and convenient. Long-term well washing operation will not affect the normal operation of the sucker rod, thereby ensuring the output of the oil well.

[0034] Specifically, the specific structure of the hydraulically controlled well flushing valve 16 is as follows: Figure 1 As shown, it includes an outer cylinder with openings at both ends, in which a piston rod 10 is provided that reciprocates along its axis; a connector 1 is provided at one end of the outer cylinder, which is connected to the oil pump body 14 through a tail pipe 15, and a switch assembly 2 connected to one end of the piston rod 10 for opening and closing the well washing channel is provided in the connector 1; a hydraulic drive assembly 12 is provided at the other end of the outer cylinder, which acts on one end of the piston rod 10 to activate the switch assembly 2; an overflow control component 5 is provided on the connector 1, which allows the well washing fluid to enter the outer cylinder to drive the hydraulic drive assembly 12 to operate. During well washing, before the well washing fluid enters the well washing valve, a small amount of well washing fluid first enters the overflow control component 5, and then enters the outer cylinder of the well washing valve through the overflow control component 5 until the pressure is sufficient to activate the hydraulic drive component 12 to push the piston rod 10 toward the end close to the switch component 2. Before the well washing channel is opened, the well washing fluid can fully soften the wax inside the oil pipe 13, ensuring the well washing effect; after the well washing channel is opened, the mixed liquid with softened wax can be quickly discharged from the well washing valve through the well washing channel, ensuring the efficiency of well washing.

[0035] Specifically, the switch assembly 2 includes a mounting seat installed in the connector 1 and a return spring I23 and a valve ball 24 arranged therein. The mounting seat is opened at both ends, and one end of the return spring I23 is connected to the valve ball 24 to block the opening at one end of the mounting seat; the return spring I23 is configured as a tower spring. Under normal conditions, the tower spring is in a compressed state, which can ensure that the valve ball 24 is blocked at one end of the mounting seat during normal oil pumping or after well washing is completed, thereby ensuring the effective closure of the well washing channel and normal production.

[0036] The outer cylinder has a plurality of drainage holes 111 arranged along the circumference at one end close to the hydraulic drive assembly 12. The connector 1, the mounting seat, the annulus of the outer cylinder and the plurality of drainage holes 111 form a well washing channel. When the well washing channel is opened, the efficient discharge of the well washing fluid can be ensured.

[0037] The end of the retaining ring 21 away from the valve seat 22 is provided with a limiting flange. The return spring I 23 is configured as a tower spring. The larger diameter end of the return spring I 23 is positioned and fixed to the limiting flange of the retaining ring 21, while the smaller diameter end of the return spring I 23 presses and seals the valve ball 24 against the end of the valve seat 22. A return spring II 6 is sleeved onto the end of the piston rod 10 near the connector 1. One end of the return spring II 6 abuts against the upper portion of the piston rod 10, while the other end abuts against the end of the valve seat 22 away from the retaining ring 21. Under normal conditions, both the return spring I 23 and the return spring II 6 are in a contracted state, ensuring that the piston rod 10 can be smoothly reset after normal pumping or well washing operations. The valve ball 24 is sealed against one end of the mounting seat, effectively closing the well washing channel and ensuring normal production. This also ensures that the well washing valve can be reused.

[0038] The mounting seat includes a retaining ring 21 and a valve seat 22 that are positioned and installed in the connector 1. The valve seat 22 is sleeved and installed in the connector 1. A rubber ring Ⅱ4 is installed on the outer wall of the valve seat 22, and is sealed to the inner wall of the connector 1 through the rubber ring Ⅱ4. The connector 1 is provided with a positioning stop Ⅰ that contacts and connects with the valve seat 22, ensuring that the valve seat 22 is installed in place. The retaining ring 21 is threadedly connected in the connector 1, and the connector 1 is provided with a positioning stop Ⅱ that contacts and connects with the retaining ring 21, ensuring that the retaining ring 21 is installed in place. The aperture of the positioning stop Ⅱ is smaller than that of the positioning stop Ⅰ. During installation, the valve seat 22 can be installed in the connector 1 first, and then the retaining ring 21 can be installed until the end of the retaining ring 21 close to the piston rod 10 contacts and connects with one end of the valve seat 22, ensuring the stability of the structure.

[0039] Specifically, the retaining ring 21 is threadedly connected to the connector 1, and a gap exists between the retaining ring 21 and the connector 1. The overflow control component 5 includes an overflow channel 51 provided on the connector 1 and an overflow valve 52 installed therein. The gap between the retaining ring 21 and the connector 1 is connected to the overflow channel 51. In order to ensure that the well washing fluid can fully soften the wax in the oil pipe 13 and prevent the well washing fluid flowing through the well washing valve from being quickly discharged, at the beginning of the well washing, a small amount of well washing fluid flowing through the well washing valve first enters through the gap between the retaining ring 21 and the connector 1, and then enters the overflow channel 51. Only when the pressure reaches the opening pressure of the overflow valve 52 will the well washing fluid enter the annulus of the outer cylinder, act on the hydraulic drive assembly 12, and then gradually drive the piston rod 10 to gradually open the well washing channel.

[0040] Specifically, the hydraulic drive assembly 12 includes a sleeve 121 slidably mounted on the end of the piston rod 10 away from the connector 1 and an oil storage tank 127 positioned at one end of the outer cylinder. One end of the oil storage tank 127 is open and the open end of the oil storage tank 127 is sealed and sleeved on the end of the sleeve 121 away from the connector 1. The sleeve 121 and the oil storage tank 127 are connected to the outside of the oil storage tank 127 through a reset spring III 123. The sleeve 121 and the oil storage tank 127 are both configured as T-shaped structures, which facilitates the installation of the reset spring III 123. The sleeve 121, the piston rod 10 and the oil storage tank 127 form an oil storage chamber 126 for storing a fixed volume of hydraulic oil. The well washing fluid passing through the relief valve 52 acts on the sleeve 121. When the pressure of the well washing fluid is sufficient to overcome the elastic force of the return spring III 123, the sleeve 121 can be pushed to move along the piston rod 10 toward the oil storage tank 127. Since the hydraulic oil in the oil storage chamber 126 is of a fixed volume and the liquid is incompressible, the thrust exerted on the sleeve 121 is transmitted to the hydraulic oil, which generates an upward thrust, thereby pushing the piston rod 10 toward the valve ball 24. When the piston rod 10 moves upward, it overcomes the elastic force of the return spring II 6, continues to move upward, and pushes open the valve ball 24, so that the well washing channel is opened, and the pressure liquid in the oil pipe 13 is directly discharged into the casing 17 of the oil well through the hydraulically controlled well washing valve 16. After the well washing is completed, the pressure in the oil pipe 13 decreases, the sliding sleeve 121 moves upward under the action of the return spring III 123, the piston rod 10 moves downward under the action of the return spring II 6, and the valve ball 24 moves downward under the action of the return spring I 23. The valve ball 24 moves downward and seats, the well washing channel is closed, and normal production is restored.

[0041] A metal piston ring 122 is mounted on one end of the outer wall of the sleeve 121, which is sealed and slidingly connected to the inner wall of the outer cylinder through the metal piston ring 122 (hard seal connection). Due to complex downhole conditions, if the valve ball 24 and valve seat 22 are not tightly closed during production, pressure will enter through the well-washing channel, bypassing the relief valve 52. Without reaching the set opening pressure, it will act on the sleeve 121 prematurely, pushing the piston rod 10 with hydraulic oil, pushing open the valve ball 24 and opening the well-washing channel, thereby affecting normal oil production. Therefore, a hard seal is set between the piston ring and the outer cylinder to release pressure, thereby offsetting the delay in production caused by the premature opening of the well-washing channel due to the loose closure of the valve ball 24. A rubber ring IV 124 is mounted on the inner wall of the oil reservoir 127 near one end of the sleeve 121, sealingly and slidingly connected to one end of the sleeve 121 via the rubber ring IV 124. A rubber ring V 125 is mounted on the end of the piston rod 10 near the oil reservoir chamber 126, sealingly and slidingly connected to one end of the inner wall of the sleeve 121 via the rubber ring V 125. The oil reservoir 127 comprises a tank body 1271 with two open ends. One end of the tank body 1271 is sleeved and slidingly connected to one end of the sleeve 121, and the other end of the tank body 1271 is sealedly connected to a plug 1272 via a rubber ring VI 128. The sleeve 121, piston rod 10, tank body 1271, and plug 1272 define the oil reservoir chamber 126. The arrangement of the rubber rings IV 124, V 125, and VI 128 prevents the hydraulic oil in the oil reservoir chamber 126 from leaking.

[0042] The sliding sleeve 121 is configured as a T-shaped sleeve, and the cross-sectional area of ​​the sliding sleeve 121 at one end away from the oil storage tank 127 is larger than that at the other end, and the cross-sectional area of ​​the sliding sleeve 121 at one end close to the oil storage tank 127 is smaller than the cross-sectional area of ​​the piston rod 10 at one end close to the oil storage tank 127. The smaller the cross-sectional area of ​​one end of the sliding sleeve 121, the greater the pressure applied to the hydraulic oil during downward movement, and the greater the thrust applied to the piston rod 10. Moreover, the larger the cross-sectional area of ​​one end of the piston rod 10, the larger the force-bearing area, and the greater the force of the hydraulic oil pushing the piston. Similarly, the greater the force to push open the valve ball 24 upward, the valve ball 24 can be smoothly lifted.

[0043] In addition, a limiting step I 81 and a limiting step II 82 are sequentially provided on the inner wall of the outer cylinder in a direction away from the connector 1. A straightening ring 7 fixedly connected to the piston rod 10 is slidably connected to the inner wall of the outer cylinder. One end of the straightening ring 7 is in contact with the limiting step I 81, ensuring that the straightening ring 7 can be driven to slide along the inner wall of the outer cylinder when the piston rod 10 moves upward. When the piston rod 10 returns downward, the setting of the limiting step I 81 ensures that the piston rod 10 returns to its original position. The straightening ring 7 is also provided with a plurality of through holes 71 along the circumference for the passage of well washing fluid, ensuring the smooth passage of the well washing fluid. The limiting step II 82 is in contact with the end of the sliding sleeve 121 near the connector 1, providing a limiting position for the return of the sliding sleeve 121 and ensuring that the sliding sleeve 121 returns to its original position.

[0044] The outer cylinder comprises a detachably connected outer cylinder I8 and an outer cylinder II11. The outer cylinders I8 and II11 are sealed together via a rubber ring III9. The end of the outer cylinder I8 facing away from the outer cylinder II11 is sealed to the connector 1 via a rubber ring I3, ensuring the seal of the outer cylinder cavity and preventing leakage of well-washing fluid from the outer cylinder. An oil storage tank 127 is mounted on the end of the outer cylinder II11 facing away from the outer cylinder I8. Multiple drainage holes 111 are circumferentially arranged on the outer cylinder II11. The aforementioned limiting step I81 is provided within the outer cylinder I8, and the aforementioned limiting step II82 is formed at the connection between the outer cylinders I8 and II11.

[0045] The working principle of the above-mentioned double-barrel oil well pump for well washing is as follows:

[0046] During the oil pumping operation, the well washing channel of the hydraulically controlled well washing valve 16 is closed, and the sucker rod 141 in the oil pump body 14 is actuated, so that the oil in the oil well enters the inner tube 143 through the oil inlet on one side of the oil pump body 14, thereby realizing the oil pumping operation.

[0047] During well washing, there is no need to perform oil pumping operations. Positive pressure is applied to the oil pipe 13 through existing hydraulic equipment, and well washing fluid (hot water) is directly injected into the oil pipe 13 to soften the wax in the oil pipe 13. The softened mixed fluid enters the outer barrel 144 and the inner barrel 143 of the double-barrel oil well pump through the oil pipe 13 to establish a positive washing cycle. After the wax is softened, it enters the hydraulically controlled well washing valve 16 through the tail pipe 15.

[0048] Flushing fluid seeps into overflow channel 51 through the gap between connector 1 and retaining ring 21. Once the pressure reaches the opening pressure of overflow valve 52, overflow valve 52 opens, allowing a slight pressure release into the annulus of outer cylinder I8. When the pressure of the flushing fluid reaches a certain level, it overcomes the force of return spring III 123, pushing sleeve 121 toward oil reservoir 127. Because the hydraulic oil in reservoir chamber 126 has a fixed volume and is incompressible, the thrust exerted on sleeve 121 is transmitted to the hydraulic oil, generating an upward thrust, thereby pushing piston rod 10 toward valve ball 24. As piston rod 10 moves upward, it overcomes the force of return spring II 6 and continues upward, pushing valve ball 24 open, opening the flushing channel and allowing the pressurized fluid in oil pipe 13 to be discharged directly into the well casing 17 through drain hole 111 of hydraulically controlled flushing valve 16.

[0049] After the well washing is completed, the pressure in the oil pipe 13 decreases, the sliding sleeve 121 moves upward under the action of the return spring III 123, the piston rod 10 moves downward under the action of the return spring II 6, and the valve ball 24 moves downward under the action of the return spring I 23. The valve ball 24 moves downward and seats, the well washing channel is closed, and normal production is restored.

[0050] In summary, the present invention uses a hydraulically controlled well flushing valve in conjunction with a double-drum oil pump, and can directly inject hot water into the oil pipe without operating, thereby establishing a positive flushing cycle, softening the wax and driving it out of the oil pipe, and restoring normal production. The operation is simple and convenient, and the normal operation of the sucker rod will not be affected, thereby ensuring the output of the oil well.

[0051] The above description is merely an illustration of some principles of the present invention. This specification is not intended to limit the invention to the specific structure and application scope shown and described. Therefore, all corresponding modifications and equivalents that may be used are within the scope of the patent applied for the invention.

Claims

1. A hydraulically controlled well flushing valve, characterized by: It comprises an outer cylinder with openings at both ends, wherein a piston rod (10) is provided in the outer cylinder and moves back and forth along its axis, and a well washing channel for discharging well washing fluid out of the outer cylinder; A connector (1) is provided at one end of the outer cylinder, and a switch assembly (2) for opening and closing the well washing channel and connected to one end of the piston rod (10) is provided in the connector (1). The switch assembly (2) includes a mounting seat with openings at both ends installed in the connector (1) and a return spring I (23) and a valve ball (24) provided therein. One end of the return spring I (23) is in contact with the valve ball (24) to block the opening at one end of the mounting seat. The end of the piston rod (10) close to the connector (1) is sleeved with a return spring II (6) in contact with the mounting seat. The other end of the outer cylinder is provided with a hydraulic drive assembly (12) that acts on one end of the piston rod (10) to activate the switch assembly (2), the hydraulic drive assembly (12) comprising a sleeve (121) slidably mounted on the end of the piston rod (10) away from the connector (1) and an oil storage tank (127) positioned and mounted on one end of the outer cylinder, the sleeve (121) being connected to the outside of the oil storage tank (127) via a return spring III (123), and the sleeve (121), the piston rod (10) and the oil storage tank (127) forming an oil storage chamber (126) for storing a fixed volume of hydraulic oil; The connector (1) is provided with an overflow control component (5) for allowing the well washing fluid to enter the outer cylinder to drive the hydraulic drive assembly (12) to operate; the mounting seat includes a retaining ring (21) and a valve seat (22) positioned and installed in the connector (1); the retaining ring (21) is close to the end of the piston rod (10) and is in contact with the valve seat (22), and the valve seat (22) is sealed and connected to the inner wall of the connector (1); the overflow control component (5) includes an overflow channel (51) provided on the connector (1) and an overflow valve (52) installed therein; the retaining ring (21) and the connector (1) are threadedly connected, and the gap between the retaining ring (21) and the connector (1) is connected to the overflow channel (51); the hydraulically controlled well washing valve is used in conjunction with a double-pump barrel oil pump.

2. The hydraulically controlled well flushing valve according to claim 1, characterized in that: A plurality of drainage holes (111) are circumferentially arranged at one end of the outer cylinder close to the hydraulic drive assembly (12); the connector (1), the mounting seat, the annulus of the outer cylinder and the plurality of drainage holes (111) form the well washing channel; and the return spring I (23) is configured as a tower spring.

3. The hydraulically controlled well flushing valve according to claim 1, characterized in that: One end of the return spring I (23) is fixed to one end of the retaining ring (21), and the other end of the return spring I (23) presses and seals the valve ball (24) at the port of the valve seat (22); one end of the return spring II (6) abuts against the stage of the piston rod (10), and the other end of the return spring II (6) abuts against the end of the valve seat (22) away from the retaining ring (21).

4. The hydraulically controlled well flushing valve according to any one of claims 1 to 3, characterized in that: One end of the oil storage tank (127) is open, and the open end of the oil storage tank (127) is sealed and sleeved on an end of the sliding sleeve (121) away from the connector (1).

5. The hydraulically controlled well flushing valve according to claim 4, characterized in that: One end of the outer wall of the sliding sleeve (121) is connected to the inner wall of the outer cylinder in a sealing and sliding manner, the other end of the outer wall of the sliding sleeve (121) is connected to one end of the oil storage tank (127) in a sealing and sliding manner, and one end of the inner wall of the sliding sleeve (121) is connected to the piston rod (10) in a sealing and sliding manner; A metal piston ring (122) is installed on the outer wall of one end of the sliding sleeve (121), and the sliding sleeve (121) is hard-sealedly connected to the inner wall of the outer cylinder through the metal piston ring (122); The sliding sleeve (121) is configured as a T-shaped sleeve, wherein the cross-sectional area of ​​one end of the sliding sleeve (121) away from the oil storage tank (127) is larger than the cross-sectional area of ​​the other end, and the cross-sectional area of ​​the end of the sliding sleeve (121) close to the oil storage tank (127) is smaller than the cross-sectional area of ​​the end of the piston rod (10) close to the oil storage tank (127).

6. The hydraulically controlled well flushing valve according to claim 4, characterized in that: The oil storage tank (127) comprises a tank body (1271) with openings at both ends. One end of the tank body (1271) is sleeve-engaged and slidably connected to one end of the sliding sleeve (121), and a threaded plug (1272) is sealed and installed at the other end of the tank body (1271). The sliding sleeve (121), the piston rod (10), the tank body (1271) and the threaded plug (1272) form the oil storage chamber (126).

7. The hydraulically controlled well flushing valve according to claim 1, characterized in that: A limiting step I (81) and a limiting step II (82) are sequentially provided on the inner wall of the outer cylinder in a direction away from the connector (1); a straightening ring (7) fixedly connected to the piston rod (10) is slidably connected to the inner wall of the outer cylinder; one end of the straightening ring (7) is in contact with the limiting step I (81); the straightening ring (7) is provided with a plurality of through holes (71) along the circumferential direction for allowing well washing fluid to pass; the limiting step II (82) is in contact with one end of the sliding sleeve (121) close to the connector (1); The outer cylinder body comprises an outer cylinder I (8) and an outer cylinder II (11) which are detachably connected. The outer cylinder I (8) and the outer cylinder II (11) are sealed and connected to each other. The end of the outer cylinder I (8) away from the outer cylinder II (11) is sealed and connected to the connector (1). The end of the outer cylinder II (11) away from the outer cylinder I (8) is installed with the oil storage tank (127). The outer cylinder II (11) is provided with a plurality of drainage holes (111) along the circumferential direction. The limiting step I (81) is provided in the outer cylinder I (8), and the limiting step II (82) is formed at the connection between the outer cylinder I (8) and the outer cylinder II (11).

8. A double-drum oil well pump capable of flushing wells, characterized in that: The invention comprises a hydraulically controlled well-flushing valve (16) and an oil pump body (14) as claimed in any one of claims 1 to 7, wherein the oil pump body (14) comprises an inner cylinder (143), an outer cylinder (144) and an oil pumping assembly arranged in the inner cylinder (143); an annular channel (145) for allowing liquid to pass through is formed between the inner cylinder (143) and the outer cylinder (144); the annular channel (145) is connected to the hydraulically controlled well-flushing valve (16) through a tail pipe (15) after confluence; and the end of the outer cylinder (144) away from the tail pipe (15) is connected to the oil pipe (13).

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