Liquid increasing device of tubing pump

Abstract

The invention relates to the technical field of oil extraction processes, in particular to a tubing pump liquid increasing device, and aims to solve the problem of pump efficiency loss of a sucker-rod pump of a pumping unit. The tubing pump liquid increasing device is arranged between an oil well pump and a standing valve and comprises an auxiliary plunger and an auxiliary pump cylinder. The auxiliary plunger is inserted into the auxiliary pump cylinder and is in sliding connection with the auxiliary pump cylinder; the auxiliary plunger comprises a plunger rod and a one-way sealing assembly, and the one-way sealing assembly is arranged on the plunger rod in a sleeving mode and inserted into the auxiliary pump cylinder. The auxiliary plunger reciprocates along the axis of the auxiliary plunger, and the one-way sealing assembly is used for preventing liquid from passing from top to bottom. According to the tubing pump liquid increasing device, under the conditions that external force is not increased and the energy of well equipment is not consumed, the descending inertia force of the oil pumping plunger is effectively utilized to accelerate the liquid production speed of the liquid inlet of the standing valve, the coefficient of fullness in an oil well pump barrel is increased, and a guarantee is provided for improving the pump efficiency and increasing the economic benefits of an oil field.

Description

Technical Field

[0001] This invention relates to the field of oil production technology, and in particular to a tubular oil pump fluid enhancement device. Background Technology

[0002] In rod pump oil production systems, one of the main reasons affecting pump efficiency is the reduction in the effective stroke of the plunger due to the elastic expansion and contraction of the sucker rod string and tubing, resulting in a 10% loss in pump efficiency. Another reason is the high flow resistance of the fixed valve at the lower end of the pump, which prevents the inlet fluid from promptly filling the pump casing volume vacated by the plunger, causing a 5% to 10% loss in pump efficiency. Existing solutions address the first reason with technologies such as tubing compensation, tubing anchoring, and sucker rod string compensation, all developed to reduce the elastic expansion and contraction of the tubing and pump rod. While these solutions have achieved some efficiency gains, they also have drawbacks, such as inaccurate dynamometer cards and damage to the casing (affecting its lifespan). There is a lack of efficiency improvement solutions specifically addressing the second reason. Summary of the Invention

[0003] The purpose of this invention is to provide a tubular oil pump fluid-increasing device to solve the problem of pump efficiency loss in rod pumps of oil pumping units.

[0004] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows:

[0005] A tubular oil pump fluid-increasing device is disposed between the oil pump and a fixed valve, and includes an auxiliary plunger and an auxiliary pump barrel;

[0006] An auxiliary plunger is inserted into the auxiliary pump cylinder and slidably connected to the auxiliary pump cylinder;

[0007] The auxiliary plunger includes a plunger rod and a one-way sealing assembly. The one-way sealing assembly is sleeved on the plunger rod and inserted into the auxiliary pump cylinder. The auxiliary plunger reciprocates along its own axis, and the one-way sealing assembly is used to prevent liquid from flowing from top to bottom.

[0008] Furthermore, the tubular oil pump fluid-increasing device also includes an energy storage spring, which abuts against the auxiliary plunger and is used to apply an upward thrust to the auxiliary plunger to drive the auxiliary plunger to move upward.

[0009] Furthermore, the one-way sealing assembly includes a sealing cup, which is fitted onto the plunger rod with its opening facing upwards;

[0010] The sealing cup expands as it moves upward to prevent the liquid from moving downward.

[0011] Furthermore, the one-way sealing assembly also includes a spacer ring, which is sleeved on the plunger rod and connected to the plunger rod;

[0012] The plurality of spacer rings are spaced apart from the plurality of sealing cups.

[0013] Furthermore, the tubular oil pump fluid booster also includes an auxiliary inlet valve, which includes an inlet valve core and an inlet valve body;

[0014] The plunger rod is connected to the lower end of the inlet valve body and is provided with a central through hole. When moving upward, the auxiliary inlet valve opens, and the liquid flows upward through the central through hole and the auxiliary inlet valve in sequence.

[0015] Furthermore, the tubular oil pump fluid replenishment device also includes a buffer cap, which is disposed above the auxiliary inlet valve and has a fluid passage.

[0016] After passing through the auxiliary inlet valve, the liquid enters the oil pump via the liquid passage.

[0017] Furthermore, the liquid passage includes an axial hole extending along the axial direction and a radial liquid passage groove extending along the radial direction. The radial liquid passage groove is connected to the axial hole, and the liquid flows through the radial liquid passage groove and the axial hole in sequence before entering the oil pump.

[0018] Furthermore, the tubular oil pump fluid-increasing device also includes a buffer pad, which is disposed between the buffer cap and the auxiliary inlet valve;

[0019] The buffer cap, the buffer pad, and the auxiliary liquid inlet valve are connected in sequence.

[0020] Furthermore, a connecting plate is provided on the buffer cap, and the connecting plate is connected to the end of the buffer pad that is away from the auxiliary liquid inlet valve;

[0021] Both the connecting plate and the buffer pad are configured as annular structures to allow the axial hole to communicate with the auxiliary inlet valve.

[0022] Furthermore, the tubular oil pump fluid booster also includes an upper reducing coupling and a lower reducing coupling, which are respectively connected to the upper and lower ends of the auxiliary pump barrel;

[0023] The upper reducing coupling is connected to the oil pump, the lower reducing coupling is connected to the fixed valve, and the inner diameter of the auxiliary pump barrel is larger than that of the oil pump barrel of the oil pump.

[0024] In summary, the technical effects achieved by this invention are as follows:

[0025] The tubular oil pump liquid-increasing device provided by the present invention is disposed between the oil pump and the fixed valve, and includes an auxiliary plunger and an auxiliary pump barrel; the auxiliary plunger is inserted into the auxiliary pump barrel and slidably connected to the auxiliary pump barrel; the auxiliary plunger includes a plunger rod and a one-way sealing assembly, the one-way sealing assembly is sleeved on the plunger rod and inserted into the auxiliary pump barrel; the auxiliary plunger reciprocates along its own axis, and the one-way sealing assembly is used to prevent liquid from flowing from top to bottom.

[0026] The tubular oil pump fluid replenishment device provided by this invention is disposed between the oil pump and the fixed valve. When the oil pump plunger descends, the traveling valve opens, simultaneously pushing the auxiliary plunger downwards. The liquid between the fixed valve and the auxiliary plunger flows upwards through the one-way sealing valve to the auxiliary pump barrel above the one-way sealing assembly and into the oil pump barrel of the oil pump. When the oil pump plunger ascends, the traveling valve closes to discharge the liquid. Simultaneously, the ascending auxiliary plunger pushes the liquid in the auxiliary pump barrel into the space vacated by the oil pump plunger in the oil pump barrel, thereby promptly filling the oil pump barrel with liquid so that the liquid can be quickly and fully replenished when the oil pump plunger descends again, improving pump efficiency. At the same time, the ascending of the auxiliary plunger reduces the pressure in the space between the auxiliary plunger and the fixed valve, accelerating the opening of the fixed valve and increasing the fluid inlet speed, thus ensuring timely replenishment for the next formation and further improving pump efficiency.

[0027] The tubular oil pump fluid enhancement device provided by this invention effectively utilizes the inertial force of the downward movement of the oil plunger to accelerate the fluid production rate of the fixed valve inlet without increasing external force or consuming the energy of the well equipment, thereby improving the filling coefficient inside the oil pump barrel and providing a guarantee for improving pump efficiency and increasing economic benefits in oil fields. Attached Figure Description

[0028] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of the tubular oil pump fluid-increasing device provided in an embodiment of the present invention;

[0030] Figure 2 This is another structural schematic diagram of the tubular oil pump fluid-increasing device provided in an embodiment of the present invention.

[0031] Icons: 100, Auxiliary plunger; 200, Auxiliary pump barrel; 300, Energy storage spring; 400, Auxiliary inlet valve; 500, Buffer cap; 600, Buffer pad; 700, Upper reducing coupling; 800, Lower reducing coupling; 110, Plunger rod; 120, One-way sealing assembly; 111, Central through hole; 121, Sealing cup; 122, Spacer ring; 410, Inlet valve core; 420, Inlet valve body; 421, Valve body; 422, Valve seat; 510, Liquid passage; 511, Axial hole; 512, Radial liquid passage groove; 520, Connecting plate; 101, Oil pump barrel; 20, Fixed valve; 301, First receiving cavity; 302, Second receiving cavity. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0034] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0035] In rod pump oil production systems, one of the main reasons affecting pump efficiency is the reduction in the effective stroke of the plunger due to the elastic expansion and contraction of the sucker rod string and tubing, resulting in a 10% loss in pump efficiency. Another reason is the high flow resistance of the fixed valve at the lower end of the pump, which prevents the inlet fluid from promptly filling the pump casing volume vacated by the plunger, causing a 5% to 10% loss in pump efficiency. Existing solutions mainly address the first reason by employing technologies such as tubing compensation, tubing anchoring, and sucker rod string compensation, achieving some efficiency improvement. However, certain problems exist, such as inaccurate dynamometer charts and damage to the casing (affecting its lifespan). There is a lack of efficiency improvement solutions specifically addressing the second reason.

[0036] In view of this, the present invention provides a tubular oil pump liquid-increasing device, disposed between the oil pump and the fixed valve 20, including an auxiliary plunger 100 and an auxiliary pump barrel 200; the auxiliary plunger 100 is inserted into the auxiliary pump barrel 200 and slidably connected to the auxiliary pump barrel 200; the auxiliary plunger 100 includes a plunger rod 110 and a one-way sealing assembly 120, the one-way sealing assembly 120 is sleeved on the plunger rod 110 and inserted into the auxiliary pump barrel 200; the auxiliary plunger 100 reciprocates along its own axis, and the one-way sealing assembly 120 is used to prevent liquid from flowing from top to bottom.

[0037] The tubular oil pump fluid replenishment device provided by this invention is disposed between the oil pump and the fixed valve 20. When the oil pump plunger descends, the traveling valve opens, simultaneously pushing the auxiliary plunger 100 downwards. The liquid between the fixed valve 20 and the auxiliary plunger 100 flows upwards through the one-way sealing valve to the auxiliary pump barrel 200 above the one-way sealing assembly 120 and into the oil pump barrel 101 of the oil pump. When the oil pump plunger ascends, the traveling valve closes to discharge the liquid. Simultaneously, the ascending auxiliary plunger 100 pushes the liquid in the auxiliary pump barrel 200 into the space vacated by the oil pump plunger in the oil pump barrel 101, thereby promptly filling the oil pump barrel 101 with liquid so that the liquid can be quickly and fully replenished when the oil pump plunger descends again, improving pump efficiency. At the same time, the ascending of the auxiliary plunger 100 reduces the pressure in the space between the auxiliary plunger 100 and the fixed valve 20, accelerating the opening of the fixed valve 20 and increasing the fluid inlet speed, thus ensuring timely replenishment for the next formation and further improving pump efficiency.

[0038] The tubular oil pump fluid enhancement device provided by this invention effectively utilizes the inertial force of the downward movement of the oil plunger to accelerate the fluid production rate at the inlet of the fixed valve 20 without increasing external force or consuming the energy of the well equipment, thereby improving the filling coefficient inside the oil pump barrel 101 and providing a guarantee for improving pump efficiency and increasing economic benefits in oil fields.

[0039] The following combination Figure 1 , Figure 2 The structure and shape of the tubular oil pump fluid booster device provided in this embodiment will be described in detail:

[0040] In this embodiment, the tubular oil pump fluid booster is disposed between the oil pump and the fixed valve 20, and includes an auxiliary plunger 100, an auxiliary pump barrel 200, an energy storage spring 300, an auxiliary inlet valve 400, a buffer cap 500, a buffer pad 600, an upper reducing coupling 700, and a lower reducing coupling 800, as shown below. Figure 1 As shown. The oil pump includes an oil plunger and an oil pump barrel 101.

[0041] Specifically, the buffer cap 500, buffer pad 600, auxiliary inlet valve 400, and auxiliary plunger 100 are connected sequentially from top to bottom. The upper reducing coupling 700, auxiliary pump barrel 200, and lower reducing coupling 800 are also connected sequentially from top to bottom. The energy storage spring 300 is fitted onto the auxiliary plunger 100, with one end abutting against the auxiliary plunger 100 and the other end abutting against the lower reducing coupling 800, and is used to apply an upward thrust to the auxiliary plunger 100 to drive it to move upward. The upper reducing coupling 700 and the lower reducing coupling 800 are respectively connected to the upper and lower ends of the auxiliary pump barrel 200. The upper reducing coupling 700 is connected to the oil pump barrel 101, and the lower reducing coupling 800 is connected to the fixed valve 20.

[0042] Specifically, the upper reducing coupling 700 has an upper inner diameter of 90mm and a lower inner diameter of 107mm, with a 45° transition between the two sections of different diameters. Both ends are equipped with female pipe threads for connection. That is, the inner diameter of the auxiliary pump barrel 200 is larger than that of the oil pump barrel 101. Similarly, the lower reducing coupling 800 has a lower inner diameter of 90mm and an upper inner diameter of 107mm, with a 45° transition between the two sections of different diameters. Both ends are equipped with female pipe threads for connection. The auxiliary pump barrel 200 is made of seamless thick-walled steel pipe, with male pipe threads machined at both ends for connection with the upper reducing coupling 700 and the lower reducing coupling 800.

[0043] In this embodiment, the auxiliary plunger 100 includes a plunger rod 110 and a one-way sealing assembly 120, which is fitted onto the plunger rod 110. Specifically, the one-way sealing assembly 120 includes a sealing cup 121 and a spacer ring 122. The spacer ring 122 is fitted onto and connected to the plunger rod 110. Multiple spacer rings 122 are spaced apart from multiple sealing cups 121 to fix the sealing cups 121. The opening of the sealing cup 121 faces upward to provide a one-way seal, preventing the liquid from flowing downward. When the auxiliary plunger 100 moves upward, the sealing cup 121 expands to close the annular space between the plunger rod 110 and the auxiliary pump cylinder 200, preventing the liquid from flowing downward. When the auxiliary plunger 100 moves downward, the sealing cup 121 contracts, allowing the liquid to pass through the gap between the sealing cup 121 and the auxiliary pump cylinder 200 under pressure and enter the upper space.

[0044] In this embodiment, one end of the energy storage spring 300 abuts against the spacer ring 122, and the other end abuts against the step on the inner wall of the lower reducing coupling 800.

[0045] In this embodiment, the auxiliary inlet valve 400 includes an inlet valve core 410 and an inlet valve body 420. The inlet valve body 420 includes a valve body 421 and a valve seat 422 mounted on the valve body 421. The plunger rod 110 is threaded to the lower end of the valve body 421.

[0046] In this embodiment, the space in the pump barrel 101 located below the plunger and above the tubular pump fluid-increasing device is designated as the first receiving cavity 301, and the space below the one-way sealing assembly 120 and the auxiliary inlet valve 400 and above the fixed valve 20 is designated as the second receiving cavity 302. The plunger rod 110 is provided with a central through hole 111, and the buffer cap 500 has a fluid passage 510 to ensure that the produced fluid enters the pump. Specifically, the fluid passage 510 includes an axial hole 511 extending axially along the plunger rod 110 and a radial fluid groove 512 extending radially along the plunger rod 110, with the radial fluid groove 512 communicating with the axial hole 511. When the liquid enters the first receiving chamber 301 from the second receiving chamber 302, there are two passages. One passage passes through the central through hole 111, the auxiliary liquid inlet valve 400 and the axial hole 511 in sequence. The other passage passes through the gap between the sealing bowl 121 and the auxiliary pump cylinder 200, the annular space formed by the auxiliary pump cylinder 200, the valve body 421 and the buffer cap 500, the radial liquid passage groove 512 and the axial hole 511 in sequence.

[0047] When the auxiliary plunger 100 moves downward, the liquid in the second receiving chamber 302 pushes the inlet valve core 410 to separate from the valve seat 422. At this time, the auxiliary inlet valve 400 opens, and the liquid enters the first receiving chamber 301 through the auxiliary inlet valve 400 and the axial hole 511. When the auxiliary plunger 100 moves upward, due to the pressure balance at both ends of the valve seat 422 and the gravity of the inlet valve core 410 itself, the inlet valve core 410 falls and sits in the valve seat 422 to block the flow of liquid. At the same time, the inlet valve body 420 moves upward with the auxiliary plunger 100 so that the inlet valve core 410 sits in the valve seat 422, and the auxiliary inlet valve 400 closes. To prevent the inlet valve core 410 from deviating, guide plates can be set to limit the radial position of the inlet valve core 410, and a channel is left between the guide plates to allow the liquid to pass through. A spring can also be set to apply a downward pulling force to the inlet valve core 410 to close the auxiliary inlet valve 400.

[0048] In this embodiment, the buffer cap 500 is provided with a connecting plate 520, which is connected to the end of the buffer pad 600 opposite to the auxiliary inlet valve 400. The connecting plate 520, the buffer pad 600, and the valve body 421 are sequentially bonded together. Both the connecting plate 520 and the buffer pad 600 are configured as annular structures to allow the axial hole 511 to communicate with the auxiliary inlet valve 400. Correspondingly, the upper end of the valve body 421 is provided with a through hole for communicating with the axial hole 511.

[0049] In this embodiment, the buffer cap 500 is used to dampen vibrations when the sucker plunger pushes the auxiliary inlet valve 400 and the auxiliary plunger 100 downwards. The buffer pad 600 is used to assist the buffer cap 500 in providing sufficient vibration damping, and the diameter of the buffer pad 600 is the same as the diameter of the connecting plate 520. The auxiliary inlet valve 400 is used to draw in the product fluid below the fixed valve 20 and lift the product fluid into the sucker pump barrel 101.

[0050] The working process of the tubular oil pump liquid booster device provided in this embodiment is as follows:

[0051] After passing the pressure test, the device was lowered into the well for completion, following the design specifications for the entire lifting tubing string.

[0052] When the pumping unit's donkey head pulls the sucker rod string, causing the sucker plunger to descend, the inertia of the downward movement of the sucker plunger pushes the buffer cap 500, buffer pad 600, auxiliary plunger 100, and auxiliary inlet valve 400 downwards. The energy storage spring 300 is compressed and stores energy, and the auxiliary inlet valve 400 opens. At this time, the product fluid in the second receiving chamber 302 is pressurized and flows upwards through two pathways into the first receiving chamber 301.

[0053] When the pumping unit's auger pulls the sucker rod string upwards, causing the plunger to move upwards, the traveling valve on the plunger closes, and the plunger moves upwards, freeing up the volume of the pump barrel 101 below it, thus increasing the volume of the first receiving chamber 301. At this time, the energy storage spring 300 pushes the auxiliary plunger 100 upwards, the auxiliary inlet valve 400 closes, and due to the one-way seal of the sealing cup 121, the produced fluid cannot enter the second receiving chamber 302 from the first receiving chamber 301. Therefore, under the push of the auxiliary plunger 100, the produced fluid can promptly enter the first receiving chamber 301 and fill the volume of the pump barrel 101 freed up by the plunger. Simultaneously, the volume of the second receiving chamber 302 increases, creating a negative pressure that draws the fixed valve 20, increasing the negative pressure above the fixed valve 20, accelerating the opening of the fixed valve 20, increasing the fluid inlet speed, and thus improving the pumping efficiency of the pump.

[0054] The tubular oil pump fluid-increasing device provided in this embodiment relies on the inertia of the sucker rod and plunger moving downwards to push the auxiliary plunger 100 downwards within the auxiliary pump barrel 200, compressing the energy storage spring 300 to store energy. Then, when the plunger moves upwards, the thrust of the energy storage spring 300 pushes the auxiliary plunger 100 upwards within the auxiliary pump barrel 200, thereby increasing the fluid supply to the oil pump barrel 101. Simultaneously, the lower end of the auxiliary plunger 100 reduces the back pressure at the fixed valve 20 to increase the fluid inlet speed and opening speed. This device also provides protection for the fixed valve 20, preventing it from being blocked, buried, or jammed by falling objects, and preventing the plunger from colliding with the cover of the fixed valve 20.

[0055] The efficiency enhancement scheme provided in this embodiment, without changing the operation of the conventional oil pump, the downhole operation construction, and the structure of the lifting tubing, involves installing a tubular oil pump fluid enhancement device between the lower end of the oil pump barrel 101 and the fixed valve 20. This device relies on the downward inertia of the oil plunger to drive the auxiliary plunger 100 to move downward within the auxiliary pump barrel 200, and then relies on the energy storage spring 300 at the lower part of the auxiliary plunger 100 to push the auxiliary plunger 100 to move upward within the auxiliary pump barrel 200. When the auxiliary plunger 100 moves upward, it increases the volume of the second receiving chamber 302, that is, the space between the lower end of the auxiliary plunger 100 and the upper end of the fixed valve 20, thereby increasing the negative pressure value at the upper part of the fixed valve 20, accelerating the opening time of the fixed valve 20 and increasing the speed at which the produced fluid enters the second receiving chamber 302; secondly, it accelerates the entry of the produced fluid into the pump barrel 101 when the auxiliary plunger 100 moves upward, thereby timely filling the volume of the pump barrel 101 vacated by the pump plunger, which is conducive to quickly and fully replenishing the produced fluid when the pump plunger moves downward, thereby achieving the purpose of improving the pump efficiency of the pump. The reason for this is that the inner diameter of the auxiliary pump barrel 200 is larger than the inner diameter of the pump barrel 101.

[0056] The tubular oil pump fluid booster device provided in this embodiment does not change its original working state during normal production. It uses the downward inertia of the oil pump plunger to push the auxiliary plunger 100 downward within the auxiliary pump barrel 200, and then pushes it upward within the auxiliary pump barrel 200 by the energy storage spring 300. This achieves the goal of increasing the fluid inlet speed of the fixed valve 20 by increasing the negative pressure value and ensuring that the produced fluid fills the oil pump barrel 101 in time by increasing the pump flow rate. Ultimately, it can improve the pump efficiency by more than 8% on the original basis.

[0057] In addition, the tubular oil pump fluid enhancement device provided in this embodiment avoids the characteristics of complex structure and enlarged pump barrel 101 of conventional efficiency enhancement technology, which can meet the needs of complex wells such as deep inclination wells, while avoiding the problems of casing damage and inaccurate dynamometer charts.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A tubular oil pump fluid-increasing device, characterized in that, It is located between the oil pump and the fixed valve (20), including an auxiliary plunger (100) and an auxiliary pump barrel (200); An auxiliary plunger (100) is inserted into the auxiliary pump cylinder (200) and slidably connected to the auxiliary pump cylinder (200); The auxiliary plunger (100) includes a plunger rod (110) and a one-way sealing assembly (120). The one-way sealing assembly (120) is sleeved on the plunger rod (110) and inserted into the auxiliary pump cylinder (200). The auxiliary plunger (100) reciprocates along its own axis, and the one-way sealing assembly (120) is used to prevent liquid from flowing from top to bottom.

2. The tubular oil pump fluid-increasing device according to claim 1, characterized in that, It also includes an energy storage spring (300) that abuts against the auxiliary plunger (100) and is used to apply an upward thrust to the auxiliary plunger (100) to drive the auxiliary plunger (100) to move upward.

3. The tubular oil pump fluid-increasing device according to claim 1, characterized in that, The one-way sealing assembly (120) includes a sealing cup (121), which is fitted onto the plunger rod (110) with the cup opening facing upwards; The sealing cup (121) expands as it moves upward to prevent the liquid from moving downward.

4. The tubular oil pump fluid-increasing device according to claim 3, characterized in that, The one-way sealing assembly (120) further includes a spacer ring (122), which is sleeved on the plunger rod (110) and connected to the plunger rod (110); The plurality of spacer rings (122) are spaced apart from the plurality of sealing cups (121).

5. The tubular oil pump fluid-increasing device according to claim 1, characterized in that, It also includes an auxiliary inlet valve (400), which includes an inlet valve core (410) and an inlet valve body (420); The plunger rod (110) is connected to the lower end of the inlet valve body (420) and is provided with a central through hole (111). When moving upward, the auxiliary inlet valve (400) is opened, and the liquid flows upward through the central through hole (111) and the auxiliary inlet valve (400) in sequence.

6. The tubular oil pump fluid-increasing device according to claim 5, characterized in that, It also includes a buffer cap (500), which is disposed above the auxiliary inlet valve (400) and has a liquid passage (510); After passing through the auxiliary inlet valve (400), the liquid enters the oil pump through the liquid passage (510).

7. The tubular oil pump fluid-increasing device according to claim 6, characterized in that, The liquid passage (510) includes an axial hole (511) extending along the axial direction and a radial liquid passage groove (512) extending along the radial direction. The radial liquid passage groove (512) is connected to the axial hole (511). Liquid flows through the radial liquid passage groove (512) and the axial hole (511) in sequence and then enters the oil pump.

8. The tubular oil pump fluid-increasing device according to claim 7, characterized in that, It also includes a buffer pad (600) disposed between the buffer cap (500) and the auxiliary inlet valve (400); The buffer cap (500), the buffer pad (600), and the auxiliary liquid inlet valve (400) are connected in sequence.

9. The tubular oil pump fluid-increasing device according to claim 8, characterized in that, A connecting plate (520) is provided on the buffer cap (500), and the connecting plate (520) is connected to the end of the buffer pad (600) away from the auxiliary liquid inlet valve (400); Both the connecting plate (520) and the buffer pad (600) are configured as annular structures so that the axial hole (511) communicates with the auxiliary inlet valve (400).

10. The tubular oil pump fluid-increasing device according to claim 1, characterized in that, It also includes an upper reducing coupling (700) and a lower reducing coupling (800), which are respectively connected to the upper and lower ends of the auxiliary pump cylinder (200); The upper reducing coupling (700) is connected to the oil pump, the lower reducing coupling (800) is connected to the fixed valve (20), and the inner diameter of the auxiliary pump barrel (200) is larger than that of the oil pump barrel (101) of the oil pump.

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