An oil well pump and an oil well pump discharge valve cover thereof

Abstract

The application discloses an oil outlet valve cover of a sucker rod pump and the sucker rod pump. The oil outlet valve cover is characterized in that the outer diameter of the oil outlet valve cover body provided with a liquid flow hole is larger than the inner diameter of a pump barrel, the upper end of the oil outlet valve cover body is connected with a sucker rod string, and the lower end of the oil outlet valve cover body is sequentially connected with a valve body of a sucker rod pump plunger and a traveling valve through a connecting short joint. The oil outlet valve cover body can move up and down in the space formed after the oil pipe is connected with an oil pipe connector and the pump barrel and is always located above the pump barrel. The sucker rod pump in the application can be applied to oil wells requiring small pump depth pumping and can also be normally applied to high-inclination wells and small-diameter sidetracking wells. The application effectively improves the working environment of the oil outlet valve cover, significantly reduces or eliminates the failure of the oil outlet valve cover caused by the above problems, and thus completely avoids the short pump inspection period and high workover operation cost caused by the failure of the oil outlet valve cover.

Description

Technical Field

[0001] This invention relates to the field of oil pump technology in oil wells of the petroleum industry, and in particular to an oil pump outlet valve cover and the oil pump thereof. Background Technology

[0002] Oil pumps are commonly used equipment in oilfield mechanical oil production technology. For some special wells, such as deep pumping wells, highly deviated pumping wells, and small-diameter sidetracking wells, small-diameter oil pumps are required for oil production due to factors such as well depth and low fluid volume. Because of the deep pump run or small wellbore, the pump barrel diameter is also correspondingly smaller. If the outlet valve cover in the small-diameter oil pump still adopts the structural design of a conventional oil pump valve cover, its strength will be significantly weakened, inevitably becoming a weak link in the entire small-diameter oil pump system.

[0003] Based on field application experience, it is clear that the outlet valve cover of small-diameter oil pumps is the most frequently problematic component. Statistics show that in oil wells using small-diameter oil pumps that experienced problems in the field, over 50% of the outlet valve covers broke off.

[0004] Not only are the outlet valve covers of small-diameter oil pumps prone to problems, but they are also a component that is prone to failure in conventional oil pumps.

[0005] Whether it's a small-diameter oil pump or a conventional oil pump, the breakage of the oil outlet valve cover results in high well workover costs and huge economic losses due to well shutdown and production stoppage. In addition to increasing production costs, it can also easily cause adverse effects such as environmental pollution.

[0006] To address the aforementioned issues, the following related patent technology has emerged: Chinese Patent Application No. 202321448956.9 discloses an integrated oil outlet valve cover and an oil pump, relating to the field of oil pump valve cover technology. This technology solves the problems of short service life and easy leakage in existing split valve covers, thus improving service life. The specific solution is as follows: It includes a hollow valve cover body. An upper connector for threaded connection of the sucker rod is fixedly provided on the upper part of the valve cover body. The internal space of the valve cover body is divided and connected by a ball stop plate. An opening groove is provided on the upper side wall of the valve cover body. The opening groove is located above the ball stop plate and communicates with the space above the ball stop plate. The space below the ball stop plate is used to install a valve ball, and a guide portion is provided within the space below the ball stop plate.

[0007] While the aforementioned utility model improves the structure of the outlet valve cover, eliminating the need for secondary assembly and effectively ensuring the overall coaxiality of the outlet valve cover, thus playing a positive role in preventing pump jamming and tripping, and also extending the service life of the valve cover, and although separating the small cross-sectional area of ​​the valve cover from the impact and friction area of ​​the valve ball, and the setting of the guide part reduces the drift of the valve ball, thereby reducing impact and oil leakage, the improved structure is still complex. It does not reduce the scouring of the valve cover opening groove by liquid, and it still cannot prevent the impact and friction between the integrated outlet valve cover and the valve ball, nor can it prevent breakage at the connection between the valve cover and the sucker rod. Furthermore, it easily increases the failure rate and still requires further improvement.

[0008] Chinese Patent Application No. 202221802627.5 discloses a novel wear-resistant and corrosion-resistant oil outlet valve cover for an oil pump, belonging to the technical field of oil pump valve covers. The aforementioned utility model includes an oil pump barrel, with a plunger assembly slidably connected to the inner wall of the barrel. The plunger assembly includes an upper oil outlet valve cover, a valve ball, a plunger, an oil inlet channel, a ball cavity, and an oil outlet channel. A plunger is fixedly installed at the upper end of the oil inlet channel, a ball cavity is fixedly installed at the upper end of the plunger, and the upper oil outlet valve cover is fixedly installed at the upper end of the ball cavity. A valve ball is disposed inside the ball cavity. The upper oil outlet valve cover has an oil outlet channel, and a scraper blade is fixedly connected to the top of the upper oil outlet valve cover. The upper oil outlet valve cover is a cylindrical shape with a constant diameter. A 0.1mm gap is provided between the outer wall of the plunger assembly and the inner wall of the oil pump barrel. The aforementioned utility model effectively increases the wear resistance and corrosion resistance of the upper oil outlet valve cover, improves its service life, and achieves the effect of reducing the number of oilfield operations and lowering oil production costs.

[0009] However, the above-mentioned utility model improves the service life by increasing the wear and corrosion resistance of the upper oil outlet valve cover, but fails to fundamentally solve the problem. It still cannot prevent the oil outlet valve cover from breaking off at the connection with the sucker rod. Moreover, the structure of the improved oil outlet valve cover is more complex, which increases the failure rate of the oil outlet valve cover, and further improvements are still needed.

[0010] Chinese Patent Application No. 201921670157.X discloses a floating valve cover and a plunger-type oil pump. The floating valve cover includes a valve cover body, the upper and lower ends of which are fixedly connected to the sucker rod and the plunger body, respectively. The valve cover body includes a circular tube section, the inner cavity of which is connected to the inner cavity of the plunger body. The tube wall of the circular tube section is provided with at least two oil outlet holes distributed circumferentially. The oil outlet holes are oblique holes, which extend outward from top to bottom along the axial direction of the valve cover body and also extend obliquely along the circumferential direction of the valve cover body. The oblique holes are all in the same circumferential direction of the valve cover body.

[0011] The aforementioned utility model connects the floating valve cover to the plunger body, which enables the oil discharged from the oil outlet hole of the floating valve cover to form a swirling flow during the plunger descent. This prevents impurities such as sand and gravel carried in the oil from settling into the annular cavity between the floating valve cover and the pump barrel. At the same time, it also plays a flushing role to remove impurities that have settled into the annular cavity between the floating valve cover and the pump barrel, reducing the risk of pump jamming.

[0012] However, the above-mentioned utility model connects the floating valve cover to the plunger body, which only reduces the risk of pump jamming, but cannot solve the problem of easy breakage at the connection between the floating valve cover and the sucker rod string and all the consequences therefrom. The above-mentioned problems of the delivery valve cover have not been solved.

[0013] For the reasons mentioned above, structural optimization of the outlet valve cover in small-diameter oil pumps and conventional oil pumps is imperative. Summary of the Invention

[0014] To address the problems existing in the prior art, this paper provides an oil pump delivery valve cover and its pump, solving the problem of breakage between the delivery valve cover and the sucker rod string in existing small-diameter and conventional oil pumps. It simplifies the structure of the delivery valve cover, changes its working position, and reduces the failure rate of the delivery valve cover, thereby reducing the problems of short pump inspection cycles and high well workover costs caused by delivery valve cover failure. This reduces production costs and improves economic efficiency.

[0015] The technical solution of the present invention is: an oil pump outlet valve cover, including an outlet valve cover body, wherein: the outer diameter of the outlet valve cover body with a liquid flow hole is larger than the inner diameter of the pump barrel and the upper end is connected to the sucker rod column, and the lower end is sequentially connected to the valve body of the oil pump plunger and the traveling valve through a connecting short section. The oil outlet valve cover body can move up and down in the space formed after the oil pipe and oil pipe connector are connected to the pump barrel, and always stays above the pump barrel.

[0016] Preferably, there is one or more connecting short sections connected to the oil outlet valve cover body. When there are two or more connecting short sections, short section couplings are used for connection. The number of connecting short sections connected to the bottom of the oil outlet valve cover body is determined according to the specific application well and the specific application of the oil pump in the application well.

[0017] Preferably, the connection length of the pump barrel is determined by the connection length of the connecting short section.

[0018] Preferably, the inner circle of the oil pipe connector is a non-uniform diameter inner circle and the lower inner cavity is smaller than the upper inner cavity; an oil pipe thread is provided in the upper inner cavity of the oil pipe connector to connect with the oil pipe, and a thread is provided in the central hole of the lower inner cavity to connect with the pump barrel; an oil outlet valve cover limiting step is formed between the central hole of the upper inner cavity and the lower inner cavity of the oil pipe connector and the connecting short section.

[0019] Preferably, the oil outlet valve cover body is a non-uniform diameter body with a solid rod body with external threads at the top and a hollow cavity body with internal threads at the bottom, and the liquid flow hole is disposed in the hollow cavity at the bottom; the solid rod body of the oil outlet valve cover body is connected to the sucker rod coupling in the sucker rod string, and the internal thread in the hollow cavity is connected to the threaded connection of the connecting short section.

[0020] Preferably, the outer diameter of the oil outlet valve cover body is more than 4 mm smaller than the inner diameter of the oil pipe in the well.

[0021] Preferably, a fluid flow annulus with a width of 2 mm or more is provided between the oil outlet valve cover body and the oil pipe in the application well.

[0022] Preferably, the fluid flow holes are disposed in the cavity wall of three or more hollow cavities located at the lower part of the oil outlet valve cover body.

[0023] Preferably, the liquid flow holes are provided in three or more locations and are located in the top cavity wall of the hollow cavity of the oil outlet valve cover body.

[0024] Preferably, the liquid flow holes are provided in three or more locations and are located in the hollow cavity and top cavity wall of the oil outlet valve cover body.

[0025] An oil pump, wherein the outer diameter of the pump barrel is set to 57 mm or less and utilizes an oil pump outlet valve cover as described in this invention.

[0026] Compared with the prior art, the significant advantages of the present invention are: the present invention can be applied to oil pumps with an outer diameter of 57mm or less, and oil pumps equipped with the oil outlet valve cover of the present invention can be applied to oil wells that require deep pumping with small pumps, and can also be applied normally to wells with high deviation and small diameter side-drilling wells.

[0027] This invention completely solves the problem of breakage between the delivery valve cover and the sucker rod string in existing small-diameter and conventional oil pumps. It simplifies the structure of the delivery valve cover and changes its working position, preventing it from being impacted and damaged by the moving valve ball. This effectively improves the working environment of the delivery valve cover, significantly reducing or eliminating malfunctions caused by the aforementioned problems, thus completely avoiding short pump inspection cycles and high well workover costs due to delivery valve cover failures. It significantly reduces production costs and improves the economic benefits of wells using this invention. The specific advantages of this invention are as follows: 1. The oil outlet valve cover of the oil pump was originally located inside the pump barrel, but was now located outside the pump barrel, thus solving the design dilemma of the oil outlet valve cover being limited by the size of the pump barrel. 2. The structure of the oil outlet valve cover has been optimized to make it simple and allow for smooth fluid flow. The outer diameter and wall thickness of the oil outlet valve cover body have been increased, so that the strength of the oil outlet valve cover is no longer the lowest among the components in this type of oil pump design. 3. The present invention provides multiple liquid flow holes in the oil outlet valve cover body and adopts various liquid flow hole design schemes, which increases the oil outlet area and reduces the scouring force of liquid on the oil outlet valve cover.

[0028] 4. In this invention, the outer diameter of the oil outlet valve cover body is larger than the outer diameter of the oil pump plunger and the inner diameter of the pump barrel. Its working position is always above the pump barrel and is not subject to collision with the moving valve ball, which improves the mechanical strength of the oil outlet valve cover. The multiple liquid flow holes therein reduce the liquid scouring force.

[0029] 5. The oil pump using the oil outlet valve cover of this invention can not only be used in side-drilling wells, but also be run into wells with high deviation for production. It completely avoids a series of problems caused by the oil outlet valve cover breaking off at the sucker rod string. Its use effect is significant and can generate significant economic and social benefits. Attached Figure Description

[0030] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure and working position of the oil outlet valve cover in this invention.

[0031] Figure 2 This is a schematic diagram showing that the liquid flow hole in the oil outlet valve cover is located in the top cavity wall of the hollow cavity.

[0032] Figure 3 This is a schematic diagram showing the liquid flow holes in the oil outlet valve cover located in the hollow cavity and the top cavity wall.

[0033] In the diagram: 1. Oil pipe; 2. Oil outlet valve cover body; 2-1. Liquid flow hole; 3. Oil pipe connector; 4. Connecting short section; 5. Short section coupling; 6. Pump barrel; 7. Oil pump plunger; 8. Floating valve ball. Detailed Implementation

[0034] The accompanying drawings are for reference and illustration only and are not intended to limit the scope of protection of this invention. The technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0036] In the description of this invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, in the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0037] See Figure 1 An oil pump outlet valve cover includes an outlet valve cover body 2, wherein: the outer diameter of the outlet valve cover body 2, which has a liquid flow hole 2-1, is larger than the inner diameter of the pump barrel 6, and its upper end is connected to the sucker rod column, and its lower end is sequentially connected to the pump plunger 7 and the valve body of the traveling valve through a connecting short section 4; the outlet valve cover body 2 can move up and down in the space formed after the oil pipe 1 is connected to the oil pipe connector 3 and the pump barrel 6, and is always located above the pump barrel 6.

[0038] In this invention, the oil outlet valve cover body 2, also known as the oil outlet valve cover, has a simple structure and is easy to manufacture. While the structure of the oil outlet valve cover body 2 is simple, its connection position has also undergone a fundamental change. Its working position is no longer inside the pump cylinder 6, but within the space formed after the oil pipe 1, oil pipe connector 3, and pump cylinder 6 are sequentially connected. Because the outer diameter of the oil outlet valve cover body 2 is larger than the inner diameter of the pump cylinder 6, it will always move up and down along the pump cylinder 6 within the oil pipe 1 and oil pipe connector 3 under the drive of the connecting short section 4, and will always be located above the pump cylinder 6. Since the inner diameter of the oil pipe 1 and oil pipe connector 3 is much larger than the inner diameter of the pump cylinder 6, and the space is relatively large, this greatly increases the possibility of increasing the manufacturing thickness of the oil outlet valve cover body 2 and facilitates its manufacturing process. Increasing the manufacturing thickness of the oil outlet valve cover body 2 also increases its strength.

[0039] After the installation and connection position of the oil outlet valve cover body 2 is changed to above the pump cylinder 6, there is no chance of collision with the traveling valve ball 8 in the traveling valve. Therefore, the oil outlet valve cover body 2 will not be impacted or damaged due to the collision of the traveling valve ball 8, and the possibility of the oil outlet valve cover body 2 breaking off at the connection with the sucker rod is avoided.

[0040] This invention effectively or completely solves the problem of easy breakage between the valve cover and sucker rod in existing oil pumps. While simplifying the structure of the outlet valve cover, it changes its working position, placing it above the pump barrel 6, thus reducing the failure rate of the outlet valve cover. This reduces or even completely avoids the problems of short pump inspection cycles and high well workover costs caused by outlet valve cover failures. It significantly reduces production costs and improves economic efficiency.

[0041] Based on the above embodiment one, the present invention also has the following embodiments: In a preferred embodiment, the connecting short section 4 connected to the oil outlet valve cover body 2 is provided as one or more. When there are two or more connecting short sections 4, they are connected by short section couplings 5. The number of connecting short sections 4 connected to the bottom of the oil outlet valve cover body 2 is determined according to the specific application well and the specific application of the oil pump in the application well.

[0042] In a preferred embodiment, the connection length of the pump cylinder 6 is determined by the connection length of the connecting section 4.

[0043] In a preferred embodiment: the inner circle of the tubing connector 3 is a non-uniform diameter inner circle, and the lower inner cavity is smaller than the upper inner cavity; a tubing thread is provided in the upper inner cavity of the tubing connector 3 to connect with the tubing 1, and a thread is provided in the central hole of the lower inner cavity to connect with... Pump cylinder 6 The connection is as follows: an oil outlet valve cover limiting step is formed between the center hole of the upper inner cavity and the lower inner cavity of the oil pipe connector 3 and the pump cylinder 6. The oil outlet valve cover body 2 is always positioned above this oil outlet valve cover limiting step.

[0044] In a preferred embodiment: the oil outlet valve cover body 2 is a non-uniform diameter body with a solid rod body having external threads at the top and a hollow cavity body having internal threads at the bottom, and the liquid flow hole 2-1 is disposed in the hollow cavity at the bottom; the solid rod body of the oil outlet valve cover body 2 is connected to the sucker rod coupling in the sucker rod string, and the internal thread in the hollow cavity is threadedly connected to the connecting short section 4.

[0045] In a preferred embodiment, the outer diameter of the oil outlet valve cover body 2 is more than 4 mm smaller than the inner diameter of the tubing 1 in the application well.

[0046] In a preferred embodiment, a fluid flow annulus with a width of more than 2 mm is provided between the oil outlet valve cover body 2 and the oil pipe 1 in the application well.

[0047] In a preferred embodiment: the fluid flow holes 2-1 are disposed in the cavity walls of three or more hollow cavities located at the lower part of the oil outlet valve cover body 2, see... Figure 1 .

[0048] In a preferred embodiment: the fluid flow holes 2-1 are provided in three or more locations within the top cavity wall of the hollow cavity of the oil outlet valve cover body 2, see... Figure 2 .

[0049] In a preferred embodiment: the fluid flow holes 2-1 are provided in three or more locations within the hollow cavity and top cavity wall of the oil outlet valve cover body 2, see... Figure 3 Because the cavity wall thickness of the oil outlet valve cover body 2 is large, it will not reduce its overall strength.

[0050] An oil pump is disclosed, wherein the outer diameter of the pump barrel 6 is set to 57 mm or less and utilizes an oil pump outlet valve cover as described in this invention. This completely solves the problem of breakage of the outlet valve cover body 2 at the connection point with the sucker rod string for small-diameter oil pumps and conventional oil pumps, significantly reducing well workover costs and substantially improving the economic benefits of oil wells using this invention. Due to its simple structure and ease of manufacture and processing, this invention has a wide range of applications and its effectiveness and promotional value are significant.

[0051] The embodiments described above are merely typical examples, but the present invention is not limited to these embodiments. Those skilled in the art can make modifications without departing from the spirit and teachings of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the inventive spirit and concept of the present invention should be included within the protection scope of the present invention. Therefore, the protection scope is not limited to the above description.

Claims

1. An oil pump outlet valve cover, comprising an outlet valve cover body (2), characterized in that, The outer diameter of the outlet valve cover body (2) with the liquid flow hole (2-1) is larger than the inner diameter of the pump barrel (6), and the upper end is connected to the sucker rod column, and the lower end is connected to the pump plunger (7) and the valve body of the traveling valve in sequence through the connecting short section (4); the outlet valve cover body (2) can move up and down in the space formed after the oil pipe (1) is connected to the oil pipe connector (3) and the pump barrel (6) and is always located above the pump barrel (6).

2. The oil pump outlet valve cover as described in claim 1, characterized in that, The connecting short section (4) connected to the oil outlet valve cover body (2) is provided in one or more places. When there are two or more connecting short sections (4), a short section coupling (5) is used for connection. The number of connecting short sections (4) connected to the bottom of the oil outlet valve cover body (2) is determined according to the specific application well and the specific application of the oil pump in the application well.

3. The oil pump outlet valve cover as described in claim 1, characterized in that, The connection length of the pump barrel (6) is determined by the connection length of the connecting section (4).

4. The oil pump outlet valve cover as described in claim 3, characterized in that, The inner circle of the oil pipe connector (3) is a non-uniform diameter inner circle and the lower inner cavity is smaller than the upper inner cavity; an oil pipe thread is provided in the upper inner cavity of the oil pipe connector (3) to connect with the oil pipe (1), and a thread is provided in the center hole of the lower inner cavity to connect with the pump cylinder (6); an oil outlet valve cover limiting step is formed between the center hole of the upper inner cavity and the lower inner cavity of the oil pipe connector (3) and the connecting short section (4).

5. The oil pump outlet valve cover as described in claim 4, characterized in that, The oil outlet valve cover body (2) is a non-uniform diameter body with a solid rod body with external threads at the top and a hollow cavity body with internal threads at the bottom. The liquid flow hole (2-1) is located in the hollow cavity at the bottom. The solid rod body of the oil outlet valve cover body (2) is connected to the sucker rod coupling in the sucker rod string, and the internal thread in the hollow cavity is threaded to the connecting short section (4).

6. The oil pump outlet valve cover as described in claim 5, characterized in that, The outer diameter of the oil outlet valve cover body (2) is more than 4 mm smaller than the inner diameter of the oil pipe (1) in the application well.

7. The oil pump outlet valve cover as described in claim 6, characterized in that, The oil outlet valve cover body (2) and the oil pipe (1) in the application well are provided with a fluid flow annulus with a width of more than 2 mm.

8. The oil pump outlet valve cover as described in claim 7, characterized in that, The liquid flow holes (2-1) are located in the cavity walls of three or more hollow cavities located at the lower part of the oil outlet valve cover body (2).

9. The oil pump outlet valve cover as described in claim 7, characterized in that, The liquid flow holes (2-1) are provided in three or more locations and are located in the top cavity wall of the hollow cavity of the oil outlet valve cover body (2).

10. The oil pump outlet valve cover as described in claim 7, characterized in that, The liquid flow holes (2-1) are provided in three or more locations and are located in the hollow cavity and top cavity wall of the oil outlet valve cover body (2).

11. An oil pump, characterized in that, The outer diameter of the pump barrel (6) is set to 57 mm or less and utilizes an oil pump outlet valve cover as described in any one of claims 1-9.

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