A tube pump suction valve

Abstract

The utility model belongs to the petroleum collection technical field relates to a tubular pump suction valve, include: valve body, fixed ring, positioning shaft, valve cover, the valve body is cylindrical and is equipped with four step holes in the inner wall, the fixed ring annular surface is equipped with the oil outlet hole, the positioning shaft is slidably connected the annular hole of fixed ring along the axial direction, the upper end surface of positioning shaft is equipped with the blind hole of opening upward along the axial direction, the upper part cylindrical surface of positioning shaft is equipped with the sliding sleeve, the valve cover is the circular truncated cone of big down small, the upper end of valve cover is equipped with the sealing gasket, the utility model discloses simple structure, the number of accessory and sealing element is few, has realized tubular pump suction valve mechanical rigid sealing and flexible material double seal simultaneously, has reduced the number of accessories in the valve, has reduced the failure rate, has reduced the maintenance cost.

Description

Technical Field

[0001] This utility model belongs to the field of petroleum extraction technology, specifically relating to a tubular pump suction valve. Background Technology

[0002] A tubular pump is a downhole device used in mechanical oil production and is a core component of rod pump oil production systems. It is named for its cylindrical main structure and is widely used in most oilfields in China. During installation, the working barrel is assembled on the surface and connected to the lower part of the tubing before being lowered into the well. Then, the suction valve is engaged, and finally, the piston is connected to the lower end of the sucker rod string and lowered into the pump casing. The tubular pump consists of a working barrel, piston, traveling valve, and suction valve. The suction valve, composed of a valve seat, valve ball, and valve cover, is installed between the lower end of the piston and the upper end of the working barrel. During the upstroke, the suction valve draws fluid from the well into the pump, ensuring unidirectional fluid flow. During the downstroke, the suction valve closes, facilitating piston venting and preventing a drop in the crude oil level in the working barrel, which would reduce the flow of crude oil into the pump during the next upstroke, thus improving oil production efficiency.

[0003] However, existing suction valves have multiple sealing structures and seals above and below the valve ball, making the suction valve structure complex, with a high failure rate, and requiring time and effort for maintenance. Moreover, the friction at the sliding connection between the upper and lower parts of the valve ball is relatively large, which means that the valve ball cannot open quickly during the upstroke to reduce the amount of liquid entering, and the valve ball cannot close quickly during the downstroke, resulting in liquid loss and reduced pump efficiency.

[0004] Therefore, a simple and efficient intake valve is needed to solve the above-mentioned technical problems. Utility Model Content

[0005] The technical solution adopted by this utility model to solve the technical problem is: a tubular pump suction valve, including: valve body, fixing ring, positioning shaft, valve cover, the valve body is cylindrical and the inner wall is provided with four stepped holes, the four stepped holes are sequentially from top to bottom as the first stepped hole, the second stepped hole, the third stepped hole and the fourth stepped hole. The retaining ring is circular in shape, and an oil outlet hole is provided on the surface of the retaining ring, which passes through the upper and lower surfaces of the retaining ring; the positioning shaft slides up and down along the axial direction and is connected to the central hole of the retaining ring. The upper end face of the positioning shaft has an upward-opening blind hole along the axial direction. A sliding sleeve is fitted over the upper cylindrical surface of the positioning shaft. The outer cylindrical surface of the sliding sleeve is smooth. The outer cylindrical surface of the sliding sleeve is slidably connected to the annular hole of the fixing ring. The valve cover is connected to the lower end of the positioning shaft. The valve cover is shaped like a frustum of a cone, wider at the top and narrower at the bottom, with a sealing gasket at the top. The first step hole is detachably connected to the outer ring of the fixing ring; the diameter of the second step hole is not less than 1.2 times the outer diameter of the upper end of the valve cover; the diameter of the third step hole is not greater than the outer diameter of the lower end of the valve cover; the fourth step hole is detachably connected to the working cylinder of the tubular pump; a tapered transition hole is provided at the junction of the second step hole and the third step hole, the taper of the transition hole matches the taper of the truncated cone of the valve cover, and the diameter of the larger hole at the upper end of the transition hole is smaller than the diameter of the second step hole; The valve body, retaining ring, positioning shaft, valve cover, and transition hole are all on the same rotating shaft.

[0006] Preferably, the sliding sleeve is made of polytetrafluoroethylene.

[0007] Preferably, the sealing gasket has an annular air bladder at its edge, and the air bladder rotates along the same axis as the sealing gasket and the valve cover; the air bladder of the sealing gasket is made of soft rubber, and the rest of the sealing gasket is made of hard rubber.

[0008] More preferably, the longitudinal section of the airbag is circular or elliptical.

[0009] More preferably, the annular mid-diameter of the airbag is equal to the upper outer diameter of the valve cover.

[0010] More preferably, when the valve cover is fully fitted onto the transition hole, the upper end face of the valve cover is flush with the opening of the transition hole. Preferably, a bushing is provided axially inside the annular hole of the fixing ring, the axial length of the bushing is not less than half the axial length of the sliding sleeve, the bushing is coaxial with the fixing ring, and the sliding sleeve is slidably connected to the inner cylinder of the bushing.

[0011] Preferably, the oil outlet holes are provided in multiple ways, and the multiple oil outlet holes are evenly distributed around the fixing ring.

[0012] Preferably, the retaining ring is threadedly connected to the first stepped hole; the valve cover is threadedly connected to the positioning shaft.

[0013] Preferably, the fourth step hole is provided with an internal thread.

[0014] The beneficial effects of this utility model are: 1. This utility model achieves a rigid seal for the tubular pump suction valve by matching a frustum-shaped valve cover with a transition hole of the same taper. A sealing gasket further seals the joint between the valve cover and the transition hole, enhancing the seal between the upper and lower cavities of the tubular pump suction valve. This utility model features a simple structure, fewer accessories and seals, and achieves both mechanical rigid sealing and flexible material dual sealing for the tubular pump suction valve, while reducing the number of internal valve components, lowering the failure rate, and reducing maintenance costs.

[0015] 2. This utility model has an annular air bladder on the outer edge of the sealing gasket. When the air bladder is not subjected to external pressure during the upstroke, it contracts radially to release a larger annular channel for the crude oil to rise. When it is subjected to external pressure during the downstroke, it expands radially to better seal the gap between the valve cover and the transition hole, providing better sealing and improving pump efficiency. Attached Figure Description

[0016] Figure 1 This is an axial sectional view of the upper stroke of a tubular pump suction valve according to this utility model; Figure 2 This is an axial sectional view of the lower stroke of this utility model; Figure 3 This is an exploded view of the present invention; Figure 4 This is the utility model Figure 1 A magnified view of the local area in direction A; Figure 5 This is the utility model Figure 2 A magnified view of the area in direction B.

[0017] In the diagram: 1. Valve body; 2. Retaining ring; 3. Positioning shaft; 4. Valve cover; 5. First step hole; 6. Second step hole; 7. Third step hole; 8. Fourth step hole; 9. Oil outlet hole; 10. Blind hole; 11. Sliding sleeve; 12. Sealing gasket; 13. Transition hole; 14. Air bladder; 15. Bushing. Detailed Implementation

[0018] The relevant technologies of this utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0019] refer to Figures 1-5 A tubular pump suction valve includes: a valve body 1, a fixing ring 2, a positioning shaft 3, and a valve cover 4. The valve body 1 is cylindrical and has four stepped holes on its inner wall. The four stepped holes are arranged from top to bottom as the first stepped hole 5, the second stepped hole 6, the third stepped hole 7, and the fourth stepped hole 8. The fixed ring 2 is circular, and an oil outlet hole 9 is provided on the circular surface of the fixed ring 2, which passes through the upper and lower surfaces of the fixed ring 2; the positioning shaft 3 slides up and down along the axial direction and is connected to the central hole of the fixed ring 2; the oil outlet hole 9 is used for the liquid to surge from the tubular pump suction valve to the tubular pump after the tubular pump suction valve is opened during the upstroke, and the gas-liquid mixture generated by the downward movement of the tubular pump piston during the downstroke drives the tubular pump suction valve to close. The central hole of the circular ring is used to provide horizontal support for the positioning shaft 3 and to provide a vertical slide for the positioning shaft 3.

[0020] The upper end face of the positioning shaft 3 is provided with an upward-opening blind hole 10 along the axial direction. The upper cylindrical surface of the positioning shaft 3 is fitted with a sliding sleeve 11. The outer cylindrical surface of the sliding sleeve 11 is smooth. The outer cylindrical surface of the sliding sleeve 11 is slidably connected to the annular hole of the fixing ring 2. The valve cover 4 is connected to the lower end of the positioning shaft 3. The smooth outer surface of the sliding sleeve 11 makes the resistance smaller when the positioning shaft 3 slides vertically along the annular hole of the fixing ring 2, and the valve cover 4 opens and closes more flexibly and quickly. The pressure from the blind hole 10 during the downstroke is more distributed from the blind hole 10 to the positioning shaft 3 and the valve cover 4, thereby closing the valve cover 4 as soon as possible, preventing more liquid from the upper part of the tubular pump suction valve from flowing to the lower part of the tubular pump suction valve, and improving the pump suction efficiency.

[0021] The valve cover 4 is in the shape of a frustum of a cone, which is larger at the top and smaller at the bottom. A sealing gasket 12 is provided at the upper end of the valve cover 4. The first step hole 5 is detachably connected to the outer ring of the fixing ring 2. The diameter of the second step hole 6 is not less than 1.2 times the outer diameter of the upper end of the valve cover 4. The diameter of the third step hole 7 is not greater than the outer diameter of the lower end of the valve cover 4. The fourth step hole 8 is detachably connected to the working cylinder of the tubular pump. A tapered transition hole 13 is provided at the junction of the second step hole 6 and the third step hole 7. The taper of the transition hole 13 matches the taper of the truncated cone of the valve cover 4. The large end diameter of the transition hole 13 is smaller than the diameter of the second step hole 6. The detachable connection between the first step hole 5 and the fixing ring 2 helps to reduce production, installation, and maintenance costs. The second step hole 6... The diameter of the valve cover 4 is not less than 1.2 times the outer diameter of the upper end of the valve cover 4, which is conducive to the passage of liquid through the annular channel between the inner wall of the second step hole 6 and the outer diameter of the upper end of the valve cover 4 during the upstroke, so that the lower chamber of the crude oil self-propelled pump suction valve enters the upper chamber. The diameter of the third step hole 7 is not greater than the outer diameter of the lower end of the valve cover 4, which is conducive to the valve cover 4 covering the transition hole 13 during the downstroke to prevent the upper chamber of the crude oil self-propelled pump suction valve from returning to the lower chamber. The taper of the transition hole 13 matches the taper of the truncated cone of the valve cover 4, so that the valve cover 4 and the transition hole 13 cover each other better. A rubber layer can also be wrapped around the conical surface of the valve cover 4 to provide better airtightness when it is closed.

[0022] The valve body 1, fixing ring 2, positioning shaft 3, valve cover 4, and transition hole 13 are all on the same rotating shaft. This coaxial design makes manufacturing and processing more convenient and provides better sealing.

[0023] Furthermore, the sliding sleeve 11 is made of polytetrafluoroethylene (PTFE). The PTFE sliding sleeve 11 has better lubricity and a lower coefficient of friction, resulting in less resistance to the sliding connection between the positioning shaft 3 and the annular hole of the fixed ring 2, and more sensitive air pressure-driven sliding during the up and down strokes.

[0024] Furthermore, an annular air bladder 14 is provided at the edge of the sealing gasket 12. The air bladder 14 rotates along the same axis as the sealing gasket 12 and the valve cover 4. The air bladder 14 of the sealing gasket 12 is made of soft rubber, while the rest of the sealing gasket 12 is made of hard rubber. The combination of the annular sealing air bladder 14 with the soft and hard rubber allows the non-air bladder portion of the sealing gasket 12 to fit more closely to the upper surface of the valve cover 4. During the upstroke, the air bladder 14 contracts radially after being unaffected by external pressure, releasing a larger annular channel for the upward flow of crude oil. During the downstroke, the air bladder 14 expands radially after being subjected to external pressure, better sealing the gap between the upper surface edge of the valve cover 4 and the upper orifice of the transition hole 13, providing better sealing performance. The combination of soft rubber and air bladder 14 allows the lower part of the air bladder 14 to expand axially better and fit the stepped joint between the upper surface edge and the upper orifice of the transition hole 13 after being subjected to pressure during the downstroke, thus providing better sealing performance than a flat solid sealing gasket.

[0025] Furthermore, the longitudinal section of the airbag 14 is either circular or elliptical. An elliptical cross-section airbag 14 provides better sealing, while a circular cross-section airbag 14 provides better liquid permeability.

[0026] Furthermore, the annular mid-diameter of the airbag 14 is equal to the upper outer diameter of the valve cover 4. This represents the optimal balance between liquid permeability and sealing.

[0027] Furthermore, when the valve cover 4 is fully fitted onto the transition hole 13, the upper end face of the valve cover 4 is flush with the opening of the transition hole 13. When the valve cover 4 is flush with the transition hole 13, the conical surface of the valve cover 4 coincides with the conical surface of the transition hole 13, resulting in the best sealing performance. Additionally, when the valve cover 4 is flush with the transition hole 13, the sealing effect of the sealing gasket 12 at the joint is also the best.

[0028] Furthermore, a bushing 15 is provided axially inside the annular hole of the fixing ring 2. The axial length of the bushing 15 is not less than half the axial length of the sliding sleeve 11. The bushing 15 is coaxial with the fixing ring 2, and the sliding sleeve 11 is slidably connected to the inner cylinder of the bushing 15. When the sliding sleeve 11 slides inside the bushing 15 and the bushing 15 is long enough, it ensures that the positioning shaft 3 and the bushing 15 are coaxial when sliding up and down, so that the radial force on the positioning shaft 3 is minimized when sliding, thereby minimizing the frictional force generated, and the valve cover 4 slides open and closes more smoothly and quickly.

[0029] Furthermore, the oil outlet holes 9 are provided in multiple locations, and the multiple oil outlet holes 9 are evenly distributed around the fixing ring 2. The evenly distributed multiple oil outlet holes 9 make the rise of crude oil more stable and uniform.

[0030] Furthermore, the retaining ring 2 is threadedly connected to the first stepped hole 5; the valve cover 4 is threadedly connected to the positioning shaft 3. Threaded connections are simpler and more reliable, facilitating installation, inspection, and maintenance.

[0031] Furthermore, the fourth stepped hole 8 is provided with an internal thread. The internal thread is used to connect the pump barrel on the lower side of the suction valve, making the connection between the suction pump and the pump barrel more convenient and reliable. Example

[0032] In actual field implementation, the working process of the tubular pump suction valve is as follows: During the upstroke, the crude oil forms a near-vacuum cavity in the blind hole 10, providing auxiliary upward force for the valve cover 4 to open the valve port. The piston of the tubular pump moves upward, causing the pressure inside the suction valve to decrease. At this time, under the action of the pressure difference, the external crude oil enters the suction valve through multiple oil outlet holes 9 on the fixed ring 2, and continues to rise along the annular channel between the second step hole 6 and the upper outer diameter of the valve cover 4, entering the upper chamber of the tubular pump. During this process, the positioning shaft 3 slides upward along the inner cylinder of the bushing 15 under the drive of air pressure. Since the sliding sleeve 11 is made of polytetrafluoroethylene, it has a very low coefficient of friction, so the sliding of the positioning shaft 3 is very sensitive, and the valve cover 4 also opens quickly, ensuring that the crude oil can smoothly enter the tubular pump. At the same time, the annular air bladder 14 at the edge of the sealing gasket 12 is not subject to external pressure during the upstroke and contracts radially, releasing a larger upward channel for crude oil, further improving the crude oil throughput.

[0033] During the downstroke, the crude oil falls due to gravity and the piston's downstroke pressure, generating downward pressure in the blind hole 10. This provides the valve cover 4 with the power to move downward and close the transition hole 13, increasing the closing speed of the valve cover 4. The downward movement of the piston in the tubular pump increases the pressure inside the suction valve. At this time, under the action of air pressure and its own gravity, the valve cover 4 quickly closes onto the transition hole 13, preventing crude oil from returning from the upper chamber to the lower chamber of the tubular pump suction valve. During this process, the positioning shaft 3 slides downward along the inner cylinder of the bushing 15. Similarly, due to the lubrication of the sliding sleeve 11, the sliding of the positioning shaft 3 remains very sensitive, and the closing action of the valve cover 4 is rapid and accurate. At the same time, the annular air bladder 14 at the edge of the sealing gasket 12 is subjected to external pressure during the downstroke, expanding radially and tightly fitting against the gap between the upper surface edge of the valve cover 4 and the upper orifice of the transition hole 13, providing an excellent sealing effect. In addition, since the upper end face of the valve cover 4 is flush with the opening of the transition hole 13 when it is completely covered by the transition hole 13, the sealing effect of the sealing gasket 12 at the joint is also optimal.

[0034] The tubular pump suction valve achieves a rigid seal by mating a frustoconical valve cover 4 with a transition hole 13 of the same taper. A sealing gasket 12 further seals the joint between the valve cover 4 and the transition hole 13, enhancing the sealing performance between the upper and lower cavities of the tubular pump suction valve. Simultaneously, the suction valve has a simple structure and requires fewer parts and seals, reducing both the failure rate and maintenance costs. Furthermore, the annular air bladder 14 on the outer edge of the sealing gasket 12 serves as a release channel and a sealing gap during the upstroke and downstroke respectively, further improving pump efficiency.

[0035] In summary, this invention achieves a rigid seal for the tubular pump suction valve by using a truncated cone-shaped valve cover that mates with a transition hole of the same taper. Furthermore, a sealing gasket seals the joint between the valve cover and the transition hole, further enhancing the seal between the upper and lower cavities of the tubular pump suction valve. This invention features a simple structure, requires fewer accessories and seals, and achieves both mechanical rigid sealing and flexible material dual sealing in the tubular pump suction valve. Simultaneously, it reduces the number of internal valve components, lowers the failure rate, and reduces maintenance costs. Therefore, this invention has broad application prospects in the field of tubular pump oil extraction.

[0036] It should be emphasized that the above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model in any way. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall still fall within the scope of the technical solution of the present utility model.

Claims

1. A tubular pump suction valve, characterized in that, include: Valve body (1), fixing ring (2), positioning shaft (3), valve cover (4). The valve body (1) is cylindrical and has four stepped holes on its inner wall. The four stepped holes are arranged from top to bottom as follows: first step hole (5), second step hole (6), third step hole (7), and fourth step hole (8). The fixing ring (2) is in the shape of a ring, and an oil outlet hole (9) is provided on the ring surface of the fixing ring (2) to pass through the upper and lower surfaces of the fixing ring (2); the positioning shaft (3) slides up and down along the axial direction to connect the central hole of the ring (2); The upper end face of the positioning shaft (3) is provided with an upward-opening blind hole (10) along the axial direction. The upper cylindrical surface of the positioning shaft (3) is fitted with a sliding sleeve (11). The outer cylindrical surface of the sliding sleeve (11) is smooth. The outer cylindrical surface of the sliding sleeve (11) is slidably connected to the annular hole of the fixing ring (2). The valve cover (4) is connected to the lower end of the positioning shaft (3). The valve cover (4) is a frustum-shaped cone with a larger top and a smaller bottom, and a sealing gasket (12) is provided at the upper end of the valve cover (4). The first stepped hole (5) is detachably connected to the outer ring of the fixing ring (2), the diameter of the second stepped hole (6) is not less than 1.2 times the outer diameter of the upper end of the valve cover (4), the diameter of the third stepped hole (7) is not greater than the outer diameter of the lower end of the valve cover (4), and the fourth stepped hole (8) is detachably connected to the working cylinder of the tubular pump; a tapered transition hole (13) is provided at the through-hole of the second stepped hole (6) and the third stepped hole (7), the taper of the transition hole (13) matches the taper of the truncated cone of the valve cover (4), and the diameter of the large hole at the upper end of the transition hole (13) is smaller than the diameter of the second stepped hole (6); The valve body (1), fixing ring (2), positioning shaft (3), valve cover (4), and transition hole (13) are all on the same rotating shaft.

2. The tubular pump suction valve according to claim 1, characterized in that, The sliding sleeve (11) is made of polytetrafluoroethylene.

3. The tubular pump suction valve according to claim 1, characterized in that, The sealing gasket (12) has an annular air bladder (14) at its edge. The air bladder (14) rotates on the same axis as the sealing gasket (12) and the valve cover (4). The air bladder (14) of the sealing gasket (12) is made of soft rubber, while the rest of the sealing gasket (12) is made of hard rubber.

4. The tubular pump suction valve according to claim 3, characterized in that, The longitudinal section of the airbag (14) is circular or elliptical.

5. A tubular pump suction valve according to claim 3, characterized in that, The annular middle diameter of the airbag (14) is equal to the upper outer diameter of the valve cover (4).

6. A tubular pump suction valve according to claim 5, characterized in that, When the valve cover (4) is fully covered by the transition hole (13), the upper end face of the valve cover (4) is flush with the opening of the transition hole (13).

7. The tubular pump suction valve according to claim 1, characterized in that, A bushing (15) is provided axially inside the annular hole of the fixed ring (2). The axial length of the bushing (15) is not less than half of the axial length of the sliding sleeve (11). The bushing (15) is coaxial with the fixed ring (2). The sliding sleeve (11) is slidably connected to the inner cylinder of the bushing (15).

8. A tubular pump suction valve according to claim 1, characterized in that, The oil outlet (9) is provided in multiple ways, and the multiple oil outlets (9) are evenly distributed around the fixing ring (2).

9. A tubular pump suction valve according to claim 1, characterized in that, The fixing ring (2) is threaded to the first stepped hole (5); the valve cover (4) is threaded to the positioning shaft (3).

10. A tubular pump suction valve according to claim 1, characterized in that, The fourth step hole (8) is provided with an internal thread.

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