Flexible valve for preventing falling objects by positive pressure on the upper part of a screw electric submersible pump

Abstract

The upper part of the screw electric submersible pump can be positively pressed to prevent the flexible valve from falling out, and relates to the technical field of oil pumping pump tools, which comprises a valve cylinder fixed on the upper port of the screw pump, a detachable lining ring connected in the valve cylinder, a high-molecular flexible valve plate fixed on the lining ring, and a flow passage is arranged in the center of the high-molecular flexible valve plate, and the center of the high-molecular flexible valve plate is convex upward and the flow passage is closed in the shutdown state. The utility model solves the problems that in the traditional technology, the impurities and other foreign matters in the oil pipe fall back into the pump when the screw pump unit is in the shutdown state, causing the blockage of the pump, and when the existing screw pump needs to be positively pressed through the oil pipe, the existing valve group structure is limited, and the pressure test function cannot be realized.

Description

Technical Field

[0001] This utility model relates to the technical field of oil pump equipment, specifically to a flexible valve on the upper part of a screw-type submersible electric pump that can be pressurized in the forward direction to prevent falling objects. Background Technology

[0002] The downhole production string configuration typically uses either a tubing anchor + screw pump, or a tubing anchor + check valve + screw pump. Screw pump production has become an important oil production method in oilfield development. However, the following problems exist during production, operation, and maintenance: First, in the event of a power outage, well shutdown due to surface failure, or check valve failure, the sucker rod may reverse direction under the action of torsional inertia. Although the surface drive unit is equipped with an anti-reverse device to reduce the torsional force, it cannot completely counteract the torsional inertia of the sucker rod, causing the sucker rod to reverse and disengage, resulting in well blockage. Second, during screw pump installation, when the rotor enters the stator and rotates in the opposite direction of production, it generates suction. At this time, pipe scraps and impurities fall into the gap between the rotor and stator, causing pump jamming and well blockage. Third, during the production process of the screw pump, the rotor oscillates due to the eccentricity. The oscillation amplitude gradually decreases from the end of the screw pump to the wellhead, but the oscillation amplitude is large near the stator. This will cause uneven wear between the lower sucker rod and the tubing, as well as severe wear between the stator and the upper part of the screw pump, affecting the effective head of the screw pump.

[0003] A prior art patent with publication number CN208546303U discloses a solution including a support column with a fixing hole. Short sections are fixedly installed on the inner walls of both sides of the fixing hole, and flexible rubber sleeves are fixedly installed on the inner walls of both sides of the fixing hole. A pump cylinder is fixedly installed on the side of the two flexible rubber sleeves that are close to each other. An upper fixing ring is fixedly installed on the inner walls of both sides of the fixing hole, and the upper fixing ring is adapted to the pump cylinder. A piston body is movably installed inside the fixing hole. Oil guide holes are opened on both sides of the piston body, and a first placement groove is opened on the top of the piston body. An upper connector is fixedly installed in the first placement groove. This design is convenient to use, allowing wells to be reopened for production even after sand jamming or burying of the screw pump following a well shutdown, without the need to replace the screw pump, thus quickly restoring production and reducing significant economic losses.

[0004] Existing devices, including those mentioned above, have gradually revealed shortcomings in the technology with use, mainly in the following aspects:

[0005] First, when the existing screw pump unit is shut down, impurities and other foreign objects in the oil pipe fall back into the pump, causing blockage.

[0006] Secondly, existing screw pumps cannot perform pressure testing when they need to be pressurized through oil pipes due to the limitations of the existing valve group structure.

[0007] In conclusion, the existing technology obviously has inconveniences and defects in practical use, so it is necessary to improve it. Utility Model Content

[0008] To address the shortcomings of existing technologies, this utility model provides a flexible valve on the upper part of a screw-type submersible electric pump that can be used for positive pressure to prevent falling objects. This valve solves the problem in traditional technologies where impurities and other foreign objects in the oil pipe fall back into the pump when the screw pump unit is stopped, causing pump blockage. It also addresses the issue that existing screw pumps, when requiring positive pressure testing through the oil pipe, are limited by the existing valve assembly structure and cannot perform pressure testing.

[0009] To achieve the above objectives, this utility model provides the following technical solution:

[0010] The upper part of the screw-type submersible electric pump has a positive pressure anti-falling object flexible valve, which includes a valve cylinder fixed to the upper port of the screw pump. A bushing is detachably connected inside the valve cylinder. A polymer flexible valve plate is fixed on the bushing. A flow channel is opened at the center of the polymer flexible valve plate. In the shutdown state, the center of the polymer flexible valve plate protrudes upward and closes the flow channel.

[0011] As an optimized solution, under positive pressure testing, the center of the molecular flexible valve plate bulges downward, thereby opening the flow channel.

[0012] As an optimized solution, in the oil pumping state, the center of the polymer flexible valve plate protrudes upward and opens the flow channel in the shutdown state.

[0013] As an optimized solution, the bushing includes an upper bushing and a lower bushing arranged side by side from top to bottom, and the outer edge of the polymer flexible valve plate is fixed in the area between the upper bushing and the lower bushing.

[0014] As an optimized solution, the lower surface of the upper liner ring is provided with a plurality of top positioning protrusions that abut against the upper surface of the polymer flexible valve plate, and the upper surface of the upper liner ring is provided with a plurality of bottom positioning protrusions that abut against the lower surface of the polymer flexible valve plate.

[0015] As an optimized solution, the distance between the top positioning protrusion and the center of the valve cylinder is greater than the distance between the bottom positioning protrusion and the center of the valve cylinder.

[0016] As an optimized solution, the adjacent top positioning protrusions and bottom positioning protrusions are arranged in a radially staggered manner.

[0017] As an optimized solution, the valve cylinder includes an upper valve cylinder and a lower valve cylinder. An upper abutment ring that abuts against the upper liner ring is fixedly connected to the inner wall of the upper valve cylinder near its lower end. A lower abutment ring that abuts against the lower liner ring is fixedly connected to the inner wall of the lower valve cylinder near its upper end.

[0018] As an optimized solution, a threaded groove is provided on the inner wall of the upper end of the lower valve cylinder, and a threaded cylinder connected to the threaded groove is provided at the lower port of the upper valve cylinder near the inner wall.

[0019] As an optimized solution, a locking nut is also threaded onto the threaded cylinder, and the lower end of the locking nut abuts against the upper end of the lower valve cylinder.

[0020] As an optimized solution, the lower valve cylinder has a lower connecting thread on its outer wall near the lower end, which is connected to the screw pump.

[0021] As an optimized solution, the upper valve cylinder has an upper connecting thread on its outer wall near the upper end, which connects to the oil pipe.

[0022] Compared with the prior art, the beneficial effects of this utility model are:

[0023] The polymer flexible valve plate is made of oil-resistant and high-temperature-resistant polymer elastomer, which can adaptively deform under complex well conditions, fit the sealing surface, and reduce the risk of wear and leakage.

[0024] During the opening and closing process, the elastic deformation of the flexible valve plate can shake off the attached particles, reduce the possibility of blockage, and extend the service life.

[0025] The valve cylinder and pump body adopt a modular design, which makes them detachable and threaded to the oil pipe, allowing for quick replacement of the valve plate;

[0026] When the unit is shut down, the polymer flexible valve plate is in a closed state under no pressure, which can effectively prevent impurities and other foreign objects in the oil pipe on the pump from falling back into the pump and causing pump blockage.

[0027] In the unit startup state, when the unit starts up, the polymer flexible valve plate can flexibly extend and retract under the action of liquid flow and pressure to realize the liquid discharge function.

[0028] Unit shutdown forward pressure test state: Forward pressure is applied through the oil pipe. At this time, the flexible valve plate can be pushed up in the opposite direction and open under the pressure and fluid flow, realizing the pressure test function. Attached Figure Description

[0029] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0030] Figure 1 This is a schematic diagram of the structure of this utility model;

[0031] Figure 2 This is a schematic diagram of the structure of the present invention in the stopped state;

[0032] Figure 3 This is a schematic diagram of the structure of the present invention in the oil extraction state;

[0033] Figure 4 This is a schematic diagram of the forward pressure test structure of this utility model.

[0034] In the diagram: 1-Screw pump; 2-Oil pipe; 3-Upper valve cylinder; 4-Lower valve cylinder; 5-Lower connecting thread; 6-Upper connecting thread; 7-Threaded groove; 8-Threaded cylinder; 9-Locking nut; 10-High polymer flexible valve plate; 11-Flow passage; 12-Upper bushing ring; 13-Lower bushing ring; 14-Top positioning protrusion; 15-Bottom positioning protrusion; 16-Upper abutment ring; 17-Lower abutment ring. Detailed Implementation

[0035] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0036] like Figures 1 to 4 As shown, the upper part of the screw-type submersible electric pump can pressurize the anti-falling object flexible valve, which includes a valve cylinder fixed to the upper port of the screw pump 1. A bushing is detachably connected inside the valve cylinder, and a polymer flexible valve plate 10 is fixed on the bushing. A flow channel 11 is opened at the center of the polymer flexible valve plate 10. In the shutdown state, the center of the polymer flexible valve plate 10 protrudes upward and closes the flow channel 11.

[0037] Under positive pressure test conditions, the center of the molecular flexible valve plate bulges downward and opens the flow channel 11.

[0038] In the oil pumping state, the center of the polymer flexible valve plate 10 protrudes upward and opens the flow channel 11 when the machine is stopped.

[0039] The bushing includes an upper bushing 12 and a lower bushing 13 arranged side by side from top to bottom, and the outer edge of the polymer flexible valve plate 10 is fixed in the area between the upper bushing 12 and the lower bushing 13.

[0040] The lower surface of the upper liner ring 12 is provided with a number of top positioning protrusions 14 that abut against the upper surface of the polymer flexible valve plate 10, and the upper surface of the upper liner ring 12 is provided with a number of bottom positioning protrusions 15 that abut against the lower surface of the polymer flexible valve plate 10.

[0041] The distance between the top positioning protrusion 14 and the center of the valve cylinder is greater than the distance between the bottom positioning protrusion 15 and the center of the valve cylinder.

[0042] The top positioning protrusion 14 and the bottom positioning protrusion 15, which are close to each other, are arranged in a radially staggered manner.

[0043] The valve cylinder includes an upper valve cylinder 3 and a lower valve cylinder 4. An upper abutment ring 16 that abuts against the upper liner ring 12 is fixedly connected to the inner wall of the upper valve cylinder 3 near the lower end. A lower abutment ring 17 that abuts against the lower liner ring 13 is fixedly connected to the inner wall of the lower valve cylinder 4 near the upper end.

[0044] A threaded groove 7 is provided on the inner wall of the upper end of the lower valve cylinder 4, and a threaded cylinder 8 connected to the threaded groove 7 is provided at the lower end of the upper valve cylinder 3 near the inner wall.

[0045] A locking nut 9 is also threaded onto the threaded cylinder 8, with the lower end of the locking nut 9 abutting against the upper end of the lower valve cylinder 4.

[0046] The lower valve cylinder 4 has a lower connecting thread 5 on its outer wall near the lower end, which is connected to the screw pump 1.

[0047] The upper valve cylinder 3 has an upper connecting thread 6 on its outer wall near the upper end, which is connected to the oil pipe 2.

[0048] The working principle of this device is as follows:

[0049] The polymer flexible valve plate 10 is made of oil-resistant and high-temperature-resistant polymer elastomer, which can adaptively deform under complex well conditions, fit the sealing surface, and reduce the risk of wear and leakage.

[0050] During the opening and closing process, the elastic deformation of the flexible valve plate can shake off the attached particles, reduce the possibility of blockage, and extend the service life.

[0051] The valve cylinder and pump body adopt a modular design, which can be disassembled and connected to the oil pipe with two threads, allowing for quick replacement of the valve plate;

[0052] When the unit is shut down, the polymer flexible valve plate 10 is in a closed state without pressure, which can effectively prevent impurities and other foreign objects in the oil pipe 2 on the pump from falling back into the pump and causing pump blockage.

[0053] In the unit startup state, when the unit starts up, under the action of liquid flow and pressure, the polymer flexible valve plate 10 can flexibly extend and retract to open, realizing the liquid discharge function;

[0054] Unit shutdown forward pressure test state: Forward pressure test is performed through oil pipe 2. At this time, under the pressure and fluid flow, the flexible valve plate 10 can be raised in the opposite direction and in the open state to realize the pressure test function.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A flexible valve for preventing falling objects from being pressurized in the upper part of a screw-type submersible electric pump, characterized in that: Includes a valve cylinder fixed to the upper port of the screw pump (1), a bushing is detachably connected inside the valve cylinder, a polymer flexible valve plate (10) is fixed on the bushing, and a flow channel (11) is opened at the center of the polymer flexible valve plate (10). In the shutdown state, the center of the polymer flexible valve plate (10) protrudes upward and closes the flow channel (11).

2. The screw-type submersible electric pump with upward pressure-resistant flexible valve for preventing falling objects as described in claim 1, characterized in that: Under positive pressure test conditions, the center of the molecular flexible valve plate bulges downward and opens the flow channel (11).

3. The screw-type submersible electric pump with a forward-pressure-activated anti-falling-object flexible valve as described in claim 2, characterized in that: In the oil pumping state, the center of the polymer flexible valve plate (10) in the shutdown state bulges upward and opens the flow channel (11).

4. The screw-type submersible electric pump with a forward-pressure-activated anti-falling-object flexible valve as described in claim 3, characterized in that: The bushing includes an upper bushing (12) and a lower bushing (13) arranged side by side from top to bottom, and the outer edge of the polymer flexible valve plate (10) is fixed in the area between the upper bushing (12) and the lower bushing (13).

5. The screw-type submersible electric pump with a forward-pressure-activated anti-falling-object flexible valve as described in claim 4, characterized in that: The lower surface of the upper liner ring (12) is provided with a plurality of top positioning protrusions (14) that abut against the upper surface of the polymer flexible valve plate (10) along the circumferential direction, and the upper surface of the upper liner ring (12) is provided with a plurality of bottom positioning protrusions (15) that abut against the lower surface of the polymer flexible valve plate (10) along the circumferential direction.

6. The screw-type submersible electric pump with a forward-pressure-activated anti-falling-object flexible valve as described in claim 5, characterized in that: The distance between the top positioning protrusion (14) and the center of the valve cylinder is greater than the distance between the bottom positioning protrusion (15) and the center of the valve cylinder.

7. The screw-type submersible electric pump with a forward-pressure-activated anti-falling-object flexible valve as described in claim 6, characterized in that: The top positioning protrusion (14) and the bottom positioning protrusion (15) that are close to each other are arranged in a radially staggered manner.

8. The screw-type submersible electric pump with a forward-pressure-activated anti-falling-object flexible valve as described in claim 7, characterized in that: The valve cylinder includes an upper valve cylinder (3) and a lower valve cylinder (4). An upper abutment ring (16) that abuts against the upper liner ring (12) is fixedly connected to the inner wall of the upper valve cylinder (3) near the lower end. A lower abutment ring (17) that abuts against the lower liner ring (13) is fixedly connected to the inner wall of the lower valve cylinder (4) near the upper end.

9. The screw-type submersible electric pump with a forward-pressure-activated anti-falling-object flexible valve as described in claim 8, characterized in that: The lower valve cylinder (4) has a threaded groove (7) on the inner wall of its upper end, and the upper valve cylinder (3) has a threaded cylinder (8) connected to the threaded groove (7) at its lower end near the inner wall.

10. The screw-type submersible electric pump with a forward-pressurizing anti-falling object flexible valve as described in claim 9, characterized in that: The threaded cylinder (8) is also threaded with a locking nut (9), the lower end of which abuts against the upper end of the lower valve cylinder (4).

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