Check valve for reciprocating electric submersible pump

Abstract

The utility model discloses a check valve for a reciprocating electric submersible pump, and belongs to the technical field of oil exploitation equipment. A spherical ring face A is machined on the outer edge of the lower end face of the valve head, a spherical ring face B is machined on the upper edge of an annular inner hole of the valve seat, and the spherical ring face A and the spherical ring face B are consistent in diameter. A leather cup is installed on the upper end face of the valve head through a bolt, and the outer circle cup edge of the leather cup is upwards attached to the inner wall of the valve body. The utility model has the beneficial effects that the valve head is of a disc-shaped structure and is sealed with the valve seat through the spherical surface, so that the guide shaft is allowed to slightly swing without influencing the sealing, the processing precision and the cost are reduced, the sectional area of an annular space between the valve head and the valve body can be increased, the flow of sucked crude oil is improved, the valve resistance is reduced, and the service life is prolonged. The packing cup is arranged to serve as power for closing the valve head, so that the opening pressure of the check valve is extremely low, and the pump efficiency of the reciprocating electric submersible pump is improved.

Description

Technical Field

[0001] This utility model relates to the field of oil extraction equipment technology, and in particular to a single-flow valve for a reciprocating submersible electric pump. Background Technology

[0002] Traditional reciprocating submersible pump well check valves rely on gravity to sit on the valve seat. When this type of check valve is used in highly deviated wells or horizontal wells, part of the weight of the valve ball or valve plate will act on the inner wall of the valve body and cannot effectively fall back to the valve seat, thus affecting the normal use of the check valve in highly deviated wells.

[0003] Publication No. CN 222615310 U discloses a one-way valve for a submersible electric pump. The centering and limiting structure restricts the reciprocating movement of the sealing ball structure along the axial direction of the one-way valve body. When the submersible electric pump stops, the sealing ball quickly sits on the valve seat under the action of the return spring force and the vertical component of gravity, thereby closing the one-way valve.

[0004] Because reciprocating submersible electric pumps rely on two check valves, one above and one below, to draw in and discharge crude oil when the reciprocating mechanism rises and falls, the presence of a return spring inside the check valve increases the opening pressure of the check valve, thus reducing pump efficiency. Utility Model Content

[0005] To address the problem of low pump efficiency in current reciprocating submersible electric pump single-flow valves, this utility model provides a single-flow valve for reciprocating submersible electric pumps.

[0006] The technical solution provided by this utility model is: a single-flow valve for a reciprocating submersible electric pump, including a valve body, the valve body being made of a section of oil pipe, the upper part of the valve body being machined with an oil pipe female thread and the lower part being machined with an oil pipe male thread, the lower part of the valve body being machined with a stepped hole, the stepped hole being connected to a valve seat with an interference fit, the valve seat being a circular ring structure, the upper part of the valve body being threadedly connected to a support plate, the support plate having a positioning hole in the center, a guide sleeve being installed inside the support plate, and the circular surface of the support plate having circumferentially distributed flow holes;

[0007] The guide sleeve is connected to the guide shaft with a clearance fit. A valve head is installed at the lower part of the guide shaft. The valve head has a disc structure.

[0008] A spherical annular surface A is machined on the outer edge of the lower end face of the valve head, and a spherical annular surface B is machined on the upper edge of the inner hole of the valve seat. The diameters of the spherical annular surface A and the spherical annular surface B are the same.

[0009] A lip cup is bolted to the upper end face of the valve head, and the outer rim of the lip cup is attached to the inner wall of the valve body.

[0010] The clearance between the guide sleeve and the guide shaft is such that the spherical annular surface A of the valve head and the spherical annular surface B of the valve seat are completely fitted together without causing mechanical interference.

[0011] The width of the spherical toroidal surface B is between 2.5 and 3.5 mm.

[0012] The guide sleeve, guide shaft, and valve seat are made of 316L material, while the valve head is made of 40Cr material.

[0013] The upper end face of the valve seat is fixedly connected with three mounting pins, which are evenly arranged around the circumference.

[0014] The lower part of the guide sleeve is the positioning tube, and the upper part of the positioning tube is the guide tube. The diameter of the guide tube is smaller than that of the positioning tube. The guide tube is connected to the positioning hole with an interference fit. The shoulder of the upper part of the positioning tube rests on the support plate.

[0015] The lower part of the guide shaft is machined with a stepped shaft with a reduced diameter. The upper end face of the valve head has a central hole. The stepped shaft of the guide shaft is inserted into the central hole, and the stepped shaft and the central hole are connected by an interference fit.

[0016] The beneficial effects of this utility model are as follows: By connecting the valve head to the guide sleeve and support plate through a guide shaft clearance fit, the valve head is not affected by gravity and falls on the valve seat at any angle, allowing normal use in highly deviated oil wells. By setting the valve head to a disc-shaped structure and sealing it with the valve seat through a spherical surface, slight oscillation of the guide shaft can be allowed without affecting the seal, reducing machining precision and cost. At the same time, the cross-sectional area of ​​the annulus between the valve head and the valve body can be increased, improving the flow rate of crude oil intake and reducing valve resistance. The use of a lip cup as the power for valve head closure results in extremely low opening pressure for the one-way valve, improving the pump efficiency of the reciprocating submersible electric pump. The separation of the valve head and guide shaft, and the interference fit of the support plate and guide sleeve can reduce costs. Attached Figure Description

[0017] Appendix Figure 1 This is a schematic diagram of the structure of this utility model;

[0018] Appendix Figure 2 This is a schematic diagram of the valve seat structure in this utility model;

[0019] Appendix Figure 3 This is a schematic diagram of the guide sleeve in this utility model;

[0020] Appendix Figure 4 This is a schematic diagram of the guide shaft in this utility model;

[0021] Appendix Figure 5 This is a schematic diagram of the valve head structure in this utility model;

[0022] Appendix Figure 6 This is a schematic diagram of the support plate structure in this utility model;

[0023] Appendix Figure 7 This is a schematic diagram of the valve body in this utility model.

[0024] In the diagram, 1-valve body, 101-oil pipe female thread, 102-oil pipe male thread, 103-stepped hole, 2-valve head, 201-spherical toroidal surface A, 202-center hole, 3-support plate, 301-positioning hole, 302-flow hole, 4-guide shaft, 401-stepped shaft, 5-valve seat, 501-spherical toroidal surface B, 502-mounting pin, 6-guide sleeve, 601-positioning tube, 602-guide tube, 7-skin cup. Detailed Implementation

[0025] like Figures 1-7 As shown, a single-flow valve for a reciprocating submersible electric pump includes a valve body 1, which is made of a section of oil pipe. The upper part of the valve body 1 is machined with an oil pipe female thread 101 and the lower part is machined with an oil pipe male thread 102. It can be installed at the upper and lower ends of the reciprocating submersible electric pump. The lower part of the valve body 1 is machined with a stepped hole 103, and a valve seat 5 is connected to the stepped hole 103 with an interference fit. The valve seat 5 is a circular ring structure. The upper part of the valve body 1 is threadedly connected to a support plate 3. The support plate 3 has a positioning hole 301 in the center. A guide sleeve 6 is installed in the support plate 3. The circular surface of the support plate 3 has circumferentially distributed flow holes 302.

[0026] The guide sleeve 6 is connected to the guide shaft 4 with a clearance fit in the inner hole. A valve head 2 is installed at the lower part of the guide shaft 4. The valve head 2 has a disc structure.

[0027] The lower end face of valve head 2 is machined with a spherical annular surface A201 on the outer edge, and the inner hole of valve seat 5 is machined with a spherical annular surface B501 on the upper edge. The diameters of spherical annular surface A201 and spherical annular surface B501 are the same. Using a spherical surface as the sealing surface can reduce the overall machining accuracy. Even if the guide shaft 4 is slightly off-center, it will not cause the sealing surface to detach, thus improving the sealing performance.

[0028] A cup 7 is bolted to the upper end face of the valve head 2, and the outer rim of the cup 7 is attached to the inner wall of the valve body 1.

[0029] When the reciprocating mechanism descends, the oil flows upward, and the circumference of the cup 7 contracts upward to accommodate the oil flow. When the reciprocating mechanism rises, under the weight of the crude oil above the cup 7, the circumference of the cup 7 adheres tightly to the inner wall of the valve body, thereby causing the valve head 2 to descend and seal with the valve seat 5. This mechanism can make the opening pressure of the single-flow valve extremely low, improving the pump efficiency of the reciprocating submersible electric pump.

[0030] The gap between the guide sleeve 6 and the guide shaft 4 is such that the spherical annular surface A201 of the valve head 2 and the spherical annular surface B501 of the valve seat 5 are completely fitted together without causing mechanical interference.

[0031] An excessively wide sealing ring may cause seal failure. Based on experience, the width of the spherical ring B501 is designed to be between 2.5 and 3.5 mm to meet the sealing requirements.

[0032] The guide sleeve 6, guide shaft 4, and valve seat 5 are made of 316L material, while the valve head 2 is made of 40Cr material. The guide sleeve 6 and guide shaft 4 are made of 316L for rust prevention and to prevent the guide from getting stuck. The valve seat 5 is made of 316L not only for this function, but also because stainless steel is relatively soft, while the valve head 2 made of 40Cr is harder. The spherical annular surface B501 is compressed and deformed, and it fits completely with the spherical annular surface A201, so that the two are sealed firmly.

[0033] The upper end face of the valve seat 5 is fixedly connected to the mounting pin 502. There are three mounting pins 502, which are evenly arranged around the circumference. During installation, the mounting pins 502 are tapped to install the valve seat 5 into the stepped hole 103 to prevent accidental operation from damaging the spherical annular surface B501, which could lead to a decline in product quality or even scrap.

[0034] By setting the valve head 2 as a disc-shaped structure and sealing the valve seat 5 with a spherical surface, the guide shaft 4 can be allowed to swing slightly without affecting the seal, reducing machining accuracy and cost. At the same time, the cross-sectional area of ​​the annulus between the valve head 2 and the valve body 1 can be increased, increasing the flow rate of crude oil intake and reducing valve resistance. The septum cup 7 is set as the power to close the valve head 2, making the opening pressure of the one-way valve extremely small and improving the pump efficiency of the reciprocating submersible electric pump.

[0035] The lower part of the guide sleeve 6 is the positioning tube 601, and the upper part of the positioning tube 601 is the guide tube 602. The diameter of the guide tube 602 is smaller than that of the positioning tube 601. The guide tube 602 is connected to the positioning hole 301 with an interference fit. The shoulder of the upper part of the positioning tube 601 rests on the support plate 3. The support plate 3 and the guide sleeve 6 are divided into two parts and are installed with an interference fit. This can save materials and processing costs while achieving the function.

[0036] The lower part of the guide shaft 4 has a stepped shaft 401 with a reduced diameter. The upper end face of the valve head 2 has a central hole 202. The stepped shaft 401 of the guide shaft 4 is inserted into the central hole 202. The stepped shaft 401 and the central hole 202 are connected by an interference fit. The guide shaft 4 and the valve head 2 are divided into two parts, which saves materials and processing costs while achieving the function.

Claims

1. A check valve for use in a reciprocating electric submersible pump, comprising a valve body (1), characterized in that: The valve body (1) is made of a section of oil pipe, the upper part of the valve body (1) is processed with oil pipe female thread (101), the lower part of the valve body (1) is processed with oil pipe male thread (102), the lower part of the valve body (1) is processed with stepped hole (103), the stepped hole (103) is connected with the valve seat (5) in interference fit, the valve seat (5) is a circular ring structure, the upper part of the valve body (1) is connected with the support disc (3) in screw thread, the center of the support disc (3) is provided with positioning hole (301), the support disc (3) is provided with guide sleeve (6), the disc surface of the support disc (3) is provided with circumferentially distributed overflow hole (302); The inner hole of the guide sleeve (6) is connected with the guide shaft (4) in clearance fit, the lower part of the guide shaft (4) is provided with valve head (2), the valve head (2) is a disc structure; The outer edge of the lower end surface of the valve head (2) is processed with spherical annular surface A (201), the inner hole of the circular ring of the valve seat (5) is processed with spherical annular surface B (501), the diameters of the spherical annular surface A (201) and the spherical annular surface B (501) are consistent; The upper end surface of the valve head (2) is provided with leather cup (7) through bolt, the outer circular bowl edge of the leather cup (7) is upwardly attached to the inner wall of the valve body (1).

2. The check valve of claim 1, wherein: The clearance between the guide sleeve (6) and the guide shaft (4) is that the spherical annular surface A (201) of the valve head (2) is completely attached with the spherical annular surface B (501) of the valve seat (5) without mechanical interference.

3. The check valve of claim 1 wherein: The width of the spherical annular surface B (501) is between 2.5-3.5mm.

4. The check valve of claim 1 wherein: The guide sleeve (6), the guide shaft (4) and the valve seat (5) are made of 316L material, the valve head (2) is made of 40Cr material.

5. The check valve of claim 1 wherein: The upper end surface of the valve seat (5) is fixedly connected with mounting pin (502), the number of the mounting pin (502) is three and is circumferentially uniformly arranged.

6. The check valve of claim 1 wherein: The lower part of the guide sleeve (6) is positioning tube (601), the upper part of the positioning tube (601) is guide tube (602), the diameter of the guide tube (602) is smaller than that of the positioning tube (601), the guide tube (602) is connected with the positioning hole (301) in interference fit, the shoulder of the upper part of the positioning tube (601) is on the lower surface of the support disc (3); The lower part of the guide shaft (4) is processed with stepped shaft (401) with reduced diameter, the upper end surface of the valve head (2) is provided with center hole (202), the stepped shaft (401) of the guide shaft (4) is inserted into the center hole (202), the stepped shaft (401) is connected with the center hole (202) in interference fit.

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