Durable plunger oil well pump capable of improving quality and efficiency

Abstract

The invention discloses a durable plunger oil well pump capable of improving quality and efficiency, and aims to solve the adverse effect of dissolved gas in an oil well on oil extraction operation, conveniently remove sand and paraffin, improve oil extraction efficiency, reduce environmental pollution and prolong the service life of the oil well pump. According to the technical scheme, an outer pipe capable of sliding up and down along a pump cylinder is arranged outside the pump cylinder; an exhaust hole is formed in an annular wall of the cylinder wall of the pump cylinder; an upper joint is additionally arranged at the top of the plunger; an air storage groove is formed in the annular wall of the plunger; and a concave hole with a downward opening is additionally formed in the fixed valve shell.

Description

[0001] Technical Field: The present invention relates to an underground oil extraction device, specifically, a high-quality, efficient, durable plunger oil pump that can improve oil extraction quality and production efficiency, reduce environmental pollution, and extend the service life of equipment.

[0002] Background Art: Oil, also known as crude oil, is a viscous crude oil liquid extracted from underground, also known as well fluid. Oil and its derivatives have very wide applications in economic development and human life. In the past century, with the rapid development of industry and social progress, the demand for fuels, mechanical products, and daily necessities by humans is large and the quality requirements are high, resulting in a large amount of underground oil being exploited, a significant reduction in the underground oil storage, an increasingly high cost of oil extraction, and an increasingly poor quality of the extracted oil. Especially for many oil wells in the middle and late stages, they are mostly in situations with high gas, water, sand, wax, etc. To solve such problems, current methods include adding supporting devices for oil-gas separation, or increasing the stroke length... These methods have problems such as high cost, complex processes, and high labor intensity to varying degrees.

[0003] A commonly used production device for oil extraction is a plunger oil pump, and its structure is as Figure 1 shown, mainly composed of a pump barrel 4, a plunger 9, an upper traveling valve 19, a traveling valve 11, and a fixed valve 20; the tubing string 2, the wellbore 1, and the sucker rod 3 are auxiliary implementations of the plunger oil pump. The pump barrel 4 and the tubing string 2 are located inside the wellbore 1; the tubing string 2 is sleeved on the outer wall of the upper part of the pump barrel 4; the plunger 9 is located inside the pump barrel 4, the upper end of the plunger 9 is fixedly connected to the sucker rod 3, and the upper end of the sucker rod 3 is connected to the pumping unit on the ground; the fixed valve 20 is a check valve, which is fixed at the middle of the bottom of the pump barrel 4; the plunger 9 moves up and down inside the pump barrel 4 driven by the sucker rod 3 to perform the oil extraction operation.

[0004] During the downstroke, the plunger 9 starts to move downwards, the fixed valve 20 at the bottom of the pump barrel 4 closes, and the upper traveling valve 19 and the traveling valve 11 of the plunger 9 open. At this time, the crude oil in the pump chamber 5 enters the tubing string 2 through the upper traveling valve 19.

[0005] During the upstroke, the plunger 9 moves from bottom to top, the upper traveling valve 19 at the upper end of the plunger 9 closes, and the fixed valve 20 at the bottom of the pump barrel 4 opens. At this time, the crude oil in the wellbore 1 enters the pump chamber 5 below the plunger 9 through the fixed valve 20, and the crude oil in the tubing string 2 is lifted to the ground by the plunger 9.

[0006] In the traditional plunger oil pump, during long-term operation day after day, its upper traveling valve 19 is frequently impacted by the upper traveling valve ball and is prone to fracture; when the oil pump operates, the clearance below the pump chamber 5 is large and there is a lot of dissolved gas, resulting in low pump efficiency and even causing accidents such as hydraulic shock and gas lock.

[0007] The fixed valve 20 is located below the pump barrel 4 and mainly consists of a fixed valve housing 12, a fixed valve ball seat 24, and a fixed valve ball 14. The lower part of the fixed valve housing 12 corresponds to the fixed valve ball 14 above the fixed valve ball seat 24. During the operation of the traditional oil pump, the fixed valve housing 12 is frequently impacted by the fixed valve ball 14 below, and the fixed valve ball 14 is easily damaged or even cracked. Summary of the Invention

[0008] To overcome the deficiencies of the traditional oil pump, the object of the present invention is to improve the traditional plunger oil pump and provide a plunger oil pump that can improve the quality of crude oil, increase oil production efficiency, and has a long service life, which is durable and efficient in improving quality.

[0009] This oil pump is realized as follows: A plunger oil pump that is durable and efficient in improving quality, including a pump barrel 4, a plunger 9, a traveling valve 11, a fixed valve 2, and a fixed valve housing 12; the fixed valve 20 is composed of a fixed valve housing 12, a fixed valve ball 14, etc.; at the upper and lower ends of the pump barrel 4, there are an upper end head 4-1 and a lower end head 4-2 respectively; there are auxiliary facilities for the oil pump, namely a wellbore 1, a tubing string 2, and a sucker rod 3.

[0010] The tubing string 2 and the pump barrel 4 are located inside the wellbore 1. The tubing string 2 is sleeved on the outer wall of the upper part of the pump barrel 4, and the plunger 9 is located inside the pump barrel 4; the fixed valve 20 is a one-way valve and is fixed at the middle of the bottom of the pump barrel 4.

[0011] The pump barrel 4 and the tubing string 2 are located inside the wellbore 1. Between the pump barrel 4 and the tubing string 2, there is an outer tube 16; the tubing string 2 is sleeved on the outer wall of the upper part of the pump barrel 4; the plunger 9 is located inside the pump barrel 4; the fixed valve housing 12 is fixed at the middle of the bottom of the pump barrel 4; the plunger 9 moves up and down inside the pump barrel 4 driven by the sucker rod 3.

[0012] On a circumferential surface in the middle of the pump barrel 4, there is one or more exhaust holes 6. The diameter of the exhaust holes 6 is 5-15 mm.

[0013] On the upper end surface of the outer tube 16, there is a circular central hole 22 (also known as the central hole of the outer tube). On the circumferential wall of the central hole 22, there are circumferential teeth, and the circumferential teeth are equally spaced by tooth-shaped grooves; the circumferential teeth of the central hole of the outer tube 16 are sleeved on the outer wall of the middle part 4-3 of the pump barrel, and there is a contact-type up-and-down sliding between the circumferential teeth and the outer wall of the middle part 4-3 of the pump barrel. The length of the outer tube 16 is such that when the top of the outer tube 16 contacts the bottom of the upper joint 4-1 of the pump barrel, the outer tube 16 vertically extends to the same height as the bottom of the pump. Thus, an annular open space is formed between the outer tube 16 and the outer wall of the pump barrel 4; The top surface of the outer tube 16 is 10-15 mm thick; the diameter of the circumferential teeth in the central hole on the top surface of the outer tube 16 is 1-4 mm larger than the diameter of the outer wall of the pump barrel (4-3).

[0014] The plunger 9 is barrel-shaped with an upward-opening top. The length of the plunger 9 corresponds to the vertical height of the exhaust hole 6 of the pump barrel 4. That is, when the plunger 9 drops to the bottom in the barrel cavity 5 of the pump barrel 4, the position of the top of the upper joint 8 of the plunger is level with the bottom position of the pump barrel exhaust hole 6. In this way, during well flushing or oil drainage, it does not affect the flow and can prevent falling objects from blocking. During the oil pumping process of the sucker rod pump: when reaching the lowest position of the downstroke, the height of the oil outlet hole 6 at the top of the plunger 9 should exceed the height of the top of the sealed section of the pump barrel 4. Otherwise, the well fluid in the lower part of the pump barrel 4 cannot be discharged due to the blockage of the oil outlet hole 6. Only when the height of the gas storage tank 10 of the plunger 9 is lower than the height of the bottom of the sealed section of the pump barrel 4 can the gas storage tank 10 effectively carry dissolved gas. During the upstroke of the sucker rod pump, the gas storage tank 10 on the outer wall of the plunger 9 must pass through the exhaust hole 6 of the pump barrel 4 to effectively discharge the dissolved gas in the gas storage tank 10 through the exhaust hole 6.

[0015] In the middle and lower part of the outer wall of the plunger 9, there is an annular concave gas storage tank 10 with a groove depth of 2 - 4 mm and a width of 80 - 200 mm.

[0016] The top of the plunger 9 is fixedly and hermetically connected to the lower end of the upper joint 8.

[0017] The upper joint 8 is shaped like an inverted barrel with a closed plane at the top; the center of its top surface is fixedly connected to the lower end of the sucker rod 3; on a circular band of the circular wall of the upper joint 8, a plurality of oil outlet holes 7 penetrating the side wall are equidistantly arranged.

[0018] The fixed valve housing 12 is located below the pump barrel 4. There is a concave hole 13 with an opening downward at the top inside the housing. Below the concave hole 13, there is a fixed valve ball 14 that can move up and down; there are fixed valve oil outlet holes 23 around the concave hole 13; on the bottom surface of the fixed valve housing 12 at the top of the concave hole 13, a low-hardness plate 21 is fixedly connected. The so-called "low hardness" refers to materials with relatively soft hardness, strong toughness, and corrosion resistance (such as aluminum plates, zinc plates, plastic plates, etc.), which are materials to prevent the fixed valve ball 14 from being damaged due to frequent impacts with the fixed valve housing 12. Such an improvement has a good protective effect on the fixed valve ball 14.

[0019] The working principle and beneficial effects of this high-quality, efficient, and durable plunger sucker rod pump are as follows: 1. It reduces the adverse effects of dissolved gas on oil production operations. In traditional sucker rod pumps, there is too much dissolved gas in the lower part of the pump cavity 5, resulting in a reduction in the efficiency of the sucker rod pump and even causing hydraulic shock and gas locking.

[0020] For the sucker rod pump of the present invention, an annular gas storage groove 10 is provided on the outer wall of the plunger 9, and an exhaust hole 6 is provided on the annular surface in the middle of the pump barrel 5. With such improvement, when the plunger 9 moves upward, the gas storage groove 10 can carry the dissolved gas at the lower part of the pump chamber 5 upward to the exhaust hole 6, and then discharge it to the outside of the pump barrel 4. The pump efficiency is improved, and accidents such as hydraulic shock and gas lock caused by gas in the pump chamber are prevented.

[0021] It is beneficial to the sand cleaning operation. During the oil production process, the well fluid generally contains impurities such as sand. When the sand content reaches a certain level, it will affect the oil production efficiency, and in severe cases, production can only be stopped for sand cleaning.

[0022] The traditional method for cleaning sand in a sucker rod pump is: first, lift the sucker rod, plunger, and tubing string out of the ground, and then lower a sand washing pipe into the oil well for operation. This method is time-consuming and laborious, increases costs, and pollutes the environment.

[0023] For the sucker rod pump of the present invention, when it is necessary to remove the sand in the oil well, there is no need to lift the sucker rod, plunger, and tubing string out of the ground. Instead, directly place the plunger at the bottom of the pump chamber and lower the tubing string to the lowest point in the well. At this time, the bottom of the outer pipe 16 is blocked due to contact with the sand layer and slides upward along the pump barrel 4-3 until the top of the outer pipe 16 contacts the bottom end of the pump barrel 4-1, sealing the top of the outer pipe 16. At this time, the tubing string and the pump chamber are connected to the inner cavity of the tubing string 2 and the wellbore 1 through the exhaust hole 7, forming a channel directly from the wellhead tubing string to the bottom of the well. Then, use a well flushing truck on the ground to directly press the well flushing fluid into the bottom of the wellbore 1 through the pipe. In this way, impurities such as sand at the bottom of the well are flushed out along the annular space between the tubing string 2 and the wellbore 1 until the ground, achieving the purpose of sand discharge.

[0024] 3. It is beneficial to the wax cleaning operation. During oil production operations, when the well fluid rises to a certain height, as the temperature drops, the wax dissolved in the well fluid will gradually condense on the inner wall of the tubing string 2 and the sucker rod 3, causing blockage and affecting production.

[0025] The traditional method for wax cleaning in a sucker rod pump is: inject hot steam, hot water, hot oil, etc. into the wellbore 1 for wax cleaning. Since the space in the wellbore 1 is large and the heat conduction is fast, a large amount of hot steam, hot water, or hot oil is required.

[0026] The wax cleaning method of the sucker rod pump of the present invention has the same procedure as sand cleaning. There is no need to lift the sucker rod 3, plunger 9, and tubing string 2 out of the ground. Just inject hot water, hot oil, or hot gas into the bottom of the wellbore 1 through the pipe to melt the wax at high temperature and high pressure, so that the wax is discharged along the exhaust hole 7 of the pump barrel 3.

[0027] 4. Prolong the service life of the plunger and prevent impurities and sand from entering the pump barrel 4, causing accidents and secondary operations.

[0028] The upper traveling valve 19 of the traditional sucker rod pump can only be made very thin due to space limitations, resulting in insufficient strength. Under the repeated impact of the upper traveling valve ball, the upper traveling valve 19 is prone to fracture, and there is a problem of short service life. In addition, during the operation of lowering the sucker rod pump into the well, pollutants and sundries will also fall into the well, blocking the fixed valve 20 and the traveling valve 11, resulting in secondary operations.

[0029] However, the sucker rod pump of the present invention completely eliminates the upper traveling valve 19, simplifies the structure, and saves costs; the top of the plunger 9 is changed to a fully sealed structure, and the oil outlet of the plunger 9 is changed from the top outlet to the side outlet. With such improvements, the strength of the upper end of the plunger 9 is increased, and the service life of the plunger is extended; in addition, during the operation of lowering the well and washing the well, the fully sealed top of the plunger 9 can prevent impurities and sand from entering the plunger 9 and the pump barrel 4; furthermore, in the event of a sudden well shutdown accident in the oil well, there will be no situation of sand jamming or sand burial.

[0030] 5. Improve the pump efficiency and the service life of the sucker rod pump The fixed valve ball 13 of the fixed valve 11 of the traditional sucker rod pump is prone to rise too high when the equipment is started, resulting in untimely closing of the fixed valve 11. The fixed valve ball 13 is prone to impact the fixed valve housing 12. Coupled with the influence of corrosion and the like, the traditional fixed valve 11 has a short service life and low pump efficiency.

[0031] The sucker rod pump of the present invention is provided with a concave hole 13 with an opening downward in the fixed valve housing 12. After the improvement of the fixed valve housing 12, due to the depth limitation of the hole and the resistance of the liquid in the hole, the falling distance of the fixed valve ball 13 during the downward stroke is short, the impact strength is reduced, and the service life of the fixed valve ball 13 is increased; the fixed valve 11 closes more timely, improving the pump efficiency.

[0032] Replaces the drain valve. When the sucker rod pump is in production operation, the tubing string 2 is filled with well fluid. When the sucker rod 3 rises, the well fluid will flow out of the ground as the tubing string 2 rises, which not only causes waste but also pollutes the environment.

[0033] The traditional method for the sucker rod pump to solve this problem is that before the tubing string 2 is lifted, the well fluid in the tubing string 2 is first drained, then the sucker rod and the like are lifted out of the wellhead, and then a drain valve is installed at the lower part of the pump barrel 4 (this installation operation is not only complex but also has poor safety). Finally, a striking rod is lowered to break open the drain valve to drain the oil.

[0034] For the sucker rod pump of the present invention, during the oil drainage operation, only the plunger 9 needs to be sunk to the bottom. At this time, the plunger The exhaust hole 6 of the upper joint 8 is opened, and a channel is formed among the inner cavity of the tubing string 2, the exhaust hole 6, and the wellbore 1. The crude oil in the tubing string 2 is directly drained into the wellbore 1 through the exhaust hole 6. Description of the Drawings

[0035] Figure 1 It is a schematic diagram of the overall structure of a traditional sucker rod pump; Figure 2 Schematic diagram of the structure of the upper joint in the sucker rod pump embodiment of the present invention; Figure 3 Schematic diagram of the structure of the fixed valve in the sucker rod pump embodiment of the present invention; Figure 4 Schematic diagram of the shape structure of the outer tube and the pump barrel and the positional relationship between the two in this embodiment; Figure 5 Schematic diagram of the overall structure of the sucker rod pump in the sucker rod pump embodiment of the present invention.

[0036] In the figure, 1 is the wellbore, 2 is the tubing string, 3 is the sucker rod, 4 is the pump barrel, 4-1 is the upper end head, 4-2 is the lower end head, 4-2A is the pump barrel chamfer, 4-3 is the middle part of the pump barrel, 5 is the pump chamber, 6 is the exhaust hole, 7 is the oil outlet hole, 8 is the upper joint, 9 is the plunger, 10 is the gas storage tank, 11 is the traveling valve, 12 is the fixed valve housing, 13 is the concave hole, 14 is the fixed valve ball, 15 is the oil inlet hole, 16 is the outer tube, 17 is the screw hole, 18 is the thread, 19 is the upper traveling valve, 20 is the fixed valve, 21 is the low-hardness plate, 22 is the central hole of the outer tube, 23 is the oil outlet hole of the fixed valve, 24 is the fixed valve ball seat, 25 is the lower joint of the fixed valve. Specific implementation mode

[0037] The following is an example of an embodiment of the present invention, and in combination with its attached Figure 2 - attached Figure 5 , the present invention will be further described.

[0038] Figure 2 It is a schematic diagram of the structure of the upper joint in this embodiment At the upper end of the plunger 9, the opening is upward; at the lower end of the upper joint 8, the opening is downward, and the height of the upper joint 8 is 200 mm. Between the upper joint 8 and the plunger 9, the diameter of the annular wall of the upper joint 8 is the same as the diameter of the annular wall of the plunger 8, and the two are hermetically connected by the upper and lower threads 18.

[0039] The top of the upper joint 8 is a plane. At the center of the plane, there is a threaded hole 17 for fixedly connecting with the lower end of the sucker rod 3; at a position 60 mm below the top of the annular side wall of the upper joint 8, 6 rectangular oil outlet holes 7 are equidistantly arranged, and the height and width of the hole diameter are 8 mm × 20 mm respectively.

[0040] Figure 3 It is a schematic diagram of the structure of the fixed valve in this embodiment The fixed valve is a one-way valve, mainly composed of a fixed valve housing 12, a fixed valve ball 14, and a fixed valve ball seat 24.

[0041] The fixed valve housing 12 is located below the pump barrel 4. In the lower inner part of the fixed valve housing 12, there is a "convex"-shaped space with an opening downward. The upper half of the "convex" space itself is a concave hole 13 with an opening downward. Below the concave hole 13, there is a fixed valve ball 14 that can move up and down. On the hard metal bottom surface of the fixed valve housing 12 at the top of the concave hole 13, a low-hardness aluminum plate 21 with a thickness of 10 mm is fixedly connected. There are fixed valve oil outlet holes 23 around the concave hole 13. The lower part of the "convex" space itself is a space with an opening downward. For the fixed valve housing 12, the bottom end of its annular wall is fixedly connected to the fixed valve ball seat 24 and the fixed valve lower sub 25. The fixed valve ball seat 24 is located above the fixed valve lower sub 25 and is connected to each other. There are communicating central holes at their axes. The fixed valve ball seat 24 is a "convex"-shaped entity. At the upper opening of the central hole of the upper half part of the entity, there is a fixed valve ball 14 that can move up and down.

[0042] The diameter of the concave hole 13 is 30 mm; the fixed valve ball 14 has a diameter of 28 mm. The depth of the concave hole is 60% of the diameter of the fixed valve ball 14. Between the top of the fixed valve ball 14 and the concave hole 13, they correspond up and down. The top of the fixed valve ball 14 is flush with the bottom of the concave hole 13 or slightly downward, not exceeding 10% of the diameter of the fixed valve ball.

[0043] Figure 4 A structural schematic diagram showing the shape and structure of the outer tube and the pump barrel and the positional relationship between the two At the upper and lower ends of the pump barrel 4, there are an upper end head 4-1 and a lower end head 4-2 respectively. On a circumferential surface of the middle part 4-3 of the pump barrel 4, an exhaust hole 6 is provided.

[0044] There is a circular central hole 22 on the upper end surface of the outer tube 16. There is a circular tooth on the annular wall of the central hole 22, and the circular tooth is equally spaced by tooth-shaped grooves. The circular tooth of the central hole of the outer tube 16 is sleeved on the outer wall of the middle part 4-3 of the pump barrel, and there is up-and-down contact sliding between the circular tooth and the outer wall of the middle part 4-3 of the pump barrel. The length of the outer tube 16 is: when the top of the outer tube 16 contacts the bottom of the pump barrel upper sub 4-1, the outer tube 16 vertically extends to the same height as the bottom of the pump. The sealing section of the pump barrel 4 is about 1.2 m long.

[0045] There is a chamfer 4-2A on the outer edge of the top of the lower sub 4-2 of the pump barrel 4, which can leave a gap between the top of the outer tube 16 and the pump barrel 4, and can discharge the dissolved gas entering the outer tube during oil production.

[0046] The top surface of the outer tube 16 is 10-15 mm thick; The diameter of the circular tooth in the central hole on the top surface of the outer tube 16 is 2 mm larger than the outer diameter of the pump barrel 4-3.

[0047] Figure 5Shows the overall structure of the sucker rod pump of this embodiment In the figure, the wellbore 1, the tubing string 2, and the sucker rod 3 are auxiliary facilities of the plunger sucker rod pump of this embodiment. The wellbore 1 and the tubing string 2 are on the periphery of the sucker rod pump. The upper and lower ends of the sucker rod 3 are respectively connected to the pumping unit on the ground and the plunger upper joint 8 in the oil well.

[0048] This plunger sucker rod pump includes a pump barrel 4, a plunger 9, a traveling valve 11, a standing valve, and an outer tube 16. The pump barrel 4 and the tubing string 2 are located inside the wellbore 1; the tubing string 2 is sleeved on the outer wall of the upper part of the pump barrel 4; the outer tube 16 is located between the wellbore 1 and the pump barrel 4; the traveling valve 11 is located at the bottom of the plunger 9; the standing valve 20 is fixed at the middle of the bottom of the pump barrel 4; the plunger 9 is located inside the pump barrel 4. The plunger 9 moves up and down inside the pump barrel 4 driven by the sucker rod 3, implementing the pumping operation.

[0049] On an annular surface in the middle of the pump barrel 4, an exhaust hole 6 is provided. The annular teeth of the central hole 22 at the upper end of the outer tube 16 are sleeved on the outer wall of the middle part 4-3 of the pump barrel, and the annular teeth slide up and down along the outer wall of the middle part 4-3 of the pump barrel. The shape and structure of the outer tube and the pump barrel and the positional relationship between the two have been introduced in detail in the previous description of Figure 4 which has been introduced in detail.

[0050] The standing valve 20 is fixed at the middle of the bottom of the pump barrel 4 and is mainly composed of a standing valve housing 12, a standing valve ball 14, and a standing valve seat 24. In the lower inner part of the standing valve housing 12, a concave hole 13 with an opening downward is provided, which has a protective effect on the standing valve ball 14. The specific structure of the standing valve 20 has been introduced in detail in the previous description of Figure 3 which has been introduced in detail.

[0051] The plunger 9 is located inside the pump barrel 4. On an annular wall in the middle and lower part of it, there is an annular gas storage groove 10. The upper end of the plunger 9 is fixedly connected to the upper joint 8, and there is an exhaust hole 6 on an annular wall of the upper joint 8. Regarding the specific structures of the plunger 9 and the upper joint 8. In the previous description of Figure 2 which has been introduced in detail for the plunger 9 and the upper joint 8.

[0052] Obviously, this embodiment is only an example of the present invention and not all of it. Based on this embodiment, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of protection of the present invention.

Claims

1. A plunger oil pump for improving quality, efficiency and durability, comprising a pump barrel (4), a plunger (9), a traveling valve (11), a standing valve (2), and a standing valve housing (12); the standing valve 20 is composed of a standing valve housing (12) and a standing valve ball (14); at the upper and lower ends of the pump barrel (4), there are an upper end head (4-1) and a lower end head (4-2) respectively; there are auxiliary facilities for the oil pump, namely a wellbore (1), a tubing string (2), and a sucker rod (3). It is characterized in that: Between the pump barrel (4) and the tubing string (2), an outer pipe (16) is provided. On an annular wall of the barrel wall of the pump barrel (4), one or more exhaust holes (6) are provided. For the outer pipe (16), there is a circular central hole (22) on its upper end face, and annular teeth are provided on the annular wall of the central hole. The annular teeth are equally spaced apart by tooth-shaped grooves; the annular teeth of the central hole (22) of the outer pipe are sleeved on the outer wall of the middle part (4-3) of the pump barrel, and the annular teeth slide up and down in contact along the outer wall of the middle part (4-3) of the pump barrel; the length of the outer pipe (16) is such that when the top of the outer pipe (16) contacts the bottom of the upper joint (4-1) of the pump barrel, the outer pipe (16) vertically extends to the same height as the bottom of the pump - thus, an annular open space is formed between the inside of the outer pipe (16) and the outer wall of the pump barrel (4). The plunger (9) is barrel-shaped with an open top; the length of the plunger (9) corresponds to the vertical height of the exhaust holes (6) of the pump barrel (4), that is, when the plunger (9) drops to the bottom of the pump barrel cavity in the pump barrel (4), the position of the top of the upper joint (8) of the plunger is at the same height as the bottom end of the exhaust hole (6) of the pump barrel. In the middle and lower part of the outer wall of the plunger (9), an annular concave gas storage groove (10) is provided. The top of the plunger (9) is fixedly and sealedly connected to the upper joint (8). The upper joint (8) is shaped like an inverted barrel, with a closed plane at the top, and is fixedly connected to the sucker rod (3) at the center of its top surface; on a circular band of the annular side wall of the upper joint (8), a plurality of oil outlet holes (7) penetrating the side wall are provided at equal intervals. The standing valve housing (12) is located below the pump barrel (4). At the top inside the standing valve housing (12), there is a concave hole (13) with an opening downward; on the standing valve housing (12) around the concave hole ((13), there are standing valve oil outlet holes (23); below the concave hole (13), there is a standing valve ball (14) that can move up and down corresponding to it.

2. The plunger oil pump for improving quality, efficiency and durability according to claim 1, It is characterized in that: The diameter of the exhaust hole (6) on the pump barrel (4) is 5 - 25 mm.

3. The plunger oil pump for improving quality, efficiency and durability according to claim 1, It is characterized in that: The outer diameter of the annular side wall of the upper joint (8) of the plunger is equal to or slightly less than 5% of the outer diameter of the plunger (9).

4. The plunger oil pump for improving quality, efficiency and durability according to claim 1, It is characterized in that: The gas storage groove (10) provided on the outer wall of the plunger (9) has a groove depth of 2 - 4 mm and a width of 80 - 200 mm.

5. The plunger oil pump for improving quality, efficiency and durability according to claim 1, It is characterized in that: For the fixed valve housing (12), a low-hardness plate (21) with a thickness of 5-20 mm is fixedly connected to the bottom surface of the fixed valve housing (12) at the top of its concave hole (13).

6. The improved-efficiency and durable plunger oil pump according to claim 1 or 2, characterized in that: For the pump barrel (4), the upper edge of the lower end head (4-2) is provided with an inclined chamfer (4-2A).

7. The improved-efficiency and durable plunger oil pump according to claim 1, characterized in that: For the outer tube (16), the thickness of its top surface is 10-15 mm; the diameter of the annular teeth in the central hole on the top surface of the outer tube (16) is 1-4 mm larger than the diameter of the outer wall of the pump barrel (4-3).

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