A slow-release screw pump well polished rod reverse torque energy backflow control valve

Abstract

The utility model discloses a kind of backflow control valves of slow-release screw rod pump well polished rod reverse torque energy, including valve body, valve ball, the valve body inside is equipped with valve cover, valve ball seat, the valve cover is equipped with oil inlet hole, the valve cover is close to the one end of valve ball seat and set limit rod, the limit rod is axially through;The valve ball is equipped with through sliding hole, the sliding hole sliding is set on limit rod, when valve ball and valve ball seat seat tight seal, valve ball does not separate limit rod.The utility model can make the liquid in oil pipe backflow to the annular space in oil jacket by the backflow of this control valve in oil return, make oil pipe pressure slowly release to the casing, reduce the impact force of liquid in oil pipe high-speed backflow to screw rod pump rotor, avoid rotor wear and tear leakage, to extend the service life of screw rod pump, extend the pump inspection period of oil well.

Description

Technical Field

[0001] This utility model relates to the field of petroleum development technology, specifically a reflux control valve for slowly releasing the reverse torque energy of the polished rod in a screw pump well. Background Technology

[0002] Screw pump well production systems are oil production equipment where an electric motor drives a screw pump rotor to rotate at high speed through a transmission device. The rotor and stator work together to lift the well fluid. Compared with other oil production technologies, screw pump oil production has the characteristics of high efficiency, low energy consumption, low maintenance costs, and strong adaptability. It is now being used more and more widely in oil extraction, especially suitable for heavy oil, high sand content, and high gas content oil fields. However, during shutdown maintenance, the screw pump rod string may reverse. High-speed reverse rotation can lead to accidents such as sucker rod disengagement, pulley ejection, and polished rod bending, posing a significant threat to the personal safety of on-site operators. Repairing the equipment after damage not only affects the well's operating rate and causes production losses, but also increases the cost of equipment repair and well maintenance.

[0003] There are two main reasons for the screw pump reversal. First, after the screw pump stops, the elastic torque energy stored in the rod string will be released in the reverse direction, causing the rod string to reverse. Second, the screw pump rotor has a helical structure. When the pump stops, under the action of the pressure difference between the liquid in the tubing and the external pipeline and the well pressure in the casing, the rotor will become a hydraulic motor, causing the rotor and the connected rod string to reverse rapidly. The greater the pressure difference between the tubing and the casing, the faster the rod string reverses and the longer it lasts, until the pressure difference between the tubing and the casing returns to equilibrium.

[0004] Existing anti-reverse devices for screw pump well strings mostly consist of mechanical anti-reverse devices installed at the pump head. After shutdown, the anti-reverse effect prevents the polished rod from reversing, but the elastic deformation energy stored in the downhole tubing does not disappear. Furthermore, the anti-reverse device is difficult to remove during well operations, and even after removal, the polished rod will still reverse at high speed. Therefore, a novel anti-reverse device is proposed to slowly release the elastic torque energy and solve the aforementioned problems.

[0005] Publication No. CN116357564A discloses a device for preventing reverse rotation of the guide rod of a screw pump, comprising a main body, a toothed block, and a limiting post. The main body has a toothed block groove and a fastening hole penetrating the main body. The toothed block is shaped to match the toothed block groove and is detachably mounted in the groove. The toothed block has a groove extending along its axis for receiving the guide rod, and the groove has protruding teeth facing the hollow area of ​​the groove, including strip-shaped protruding teeth extending parallel to the axis. The limiting post is mounted in the fastening hole and extends at least a predetermined length in a direction perpendicular to the axis. This predetermined length ensures that the limiting post can abut against a base for supporting the drive unit when the device is mounted on the guide rod.

[0006] This existing technology can only temporarily stop the polished rod from reversing, without eliminating the power source causing the polished rod to reverse. Therefore, the device is ineffective during operation and shutdown of the screw pump well. Furthermore, because the device is subjected to reversing torque during use, disassembling it is extremely dangerous, as tools and parts of the device can easily fly out, causing personal injury accidents.

[0007] Announcement No. CN205423157U discloses a screw pump reversing downhole damping control valve. The upper valve body has a stepped central hole, and three flow channels are evenly distributed around the central hole. Three dovetail grooves are evenly machined on the valve seat. A sliding switch is installed in the dovetail groove. The sliding switch has multiple fixing grooves, and a fixing plate is inserted in the fixing groove of the sliding switch.

[0008] The existing technology has a complex overall structure, and the slide switch has multiple V-shaped fixing grooves. The adjustment and fixation of the slide switch are achieved by inserting a fixing plate into the V-shaped fixing grooves. The V-shaped fixing grooves are prone to slippage under high pressure, causing the device to fail.

[0009] Announcement No. CN210289709U discloses an electric submersible pump backflow control valve, comprising: a valve body, a valve core, and a fixing component; the valve core is a hollow structure with a first through hole on the bottom wall of a first end and an opening at a second end opposite to the first end, and at least one second through hole on the side wall of the valve core; a protruding structure protruding inward along the circumferential direction is provided at a first preset position inside the valve body; when the valve core is located at the first preset position, the second through hole is blocked by the protruding structure of the valve body, and when the valve core moves away from the first preset position along a second direction, the second through hole is in a conductive state; a fixing component is provided at the second preset position inside the valve body.

[0010] The strength of the contact portion between the cylindrical valve core and the valve seat in the prior art is not as good as that of the valve ball of the present invention, and the service life of the prior art is shorter than that of the present invention.

[0011] In summary, the technical solutions, technical problems to be solved, and beneficial effects of the above-disclosed technologies are all different from those of this utility model. For more technical features, technical problems to be solved, and beneficial effects of this utility model, the above-disclosed technical documents do not provide any technical inspiration. Utility Model Content

[0012] In order to overcome the shortcomings of the prior art and solve at least one of the technical problems mentioned in the background art, the present invention provides a reflux control valve for slowly releasing the reverse torque energy of the polished rod of a screw pump well.

[0013] To achieve the above objectives, the present invention adopts the following technical solution:

[0014] A reflux control valve for slowly releasing the reverse torque energy of a screw pump well's polished rod includes a valve body and a valve ball. The valve body contains a valve cover and a valve ball seat. The valve cover has an oil inlet hole, and a limiting rod is provided at one end of the valve cover near the valve ball seat, the limiting rod being axially through. The valve ball has a through-hole sliding hole, which slidably fits onto the limiting rod. When the valve ball and valve ball seat are seated and sealed, the valve ball does not detach from the limiting rod.

[0015] Furthermore, the limiting rod is a circular tube rod.

[0016] Furthermore, the valve ball is a solid sphere, and the valve ball has a sliding hole passing through the center of the sphere. The sliding hole, the limiting rod, and the valve ball seat are coaxial.

[0017] Furthermore, the valve cover is plate-shaped, and at least two oil inlet holes are evenly distributed around the circumference of the valve cover.

[0018] Furthermore, the upper edge of the valve ball seat is a conical surface or an arc surface.

[0019] Furthermore, the valve body is separated from the valve cover and the valve ball seat by a pipe thread joint structure.

[0020] Furthermore, an upper connector is provided at the upper end of the valve body, and a pipe thread is provided on the inner wall of the upper end of the upper connector; a lower connector is provided at the lower end of the valve body, and a pipe thread is provided on the outer wall of the lower end of the lower connector.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. This utility model can return the liquid in the tubing to the annular space of the casing through the return oil hole in the control valve, so that the pressure in the tubing is slowly released into the casing, reducing the impact force of the high-speed return of the liquid in the tubing on the screw pump rotor, avoiding leakage after rotor wear, thereby extending the service life of the screw pump and extending the pump inspection cycle of the oil well.

[0023] 2. This utility model is easy to install. The connecting thread type is compatible with the downhole tubing of the screw pump well. It can be quickly connected to the tubing without hot work and can replace the downhole limiter. After the screw pump rotor is lowered to the position of this device, it is blocked by the valve cover and cannot be lowered further. It can be raised to prevent impact and production can be resumed, reducing operating costs.

[0024] 3. This utility model has a reasonable structure and reliable principle, avoiding accidents such as sucker rod disengagement, pulley ejection, and sucker rod bending caused by high-speed reverse rotation of the polished rod, reducing equipment damage, lowering the personal safety risks to operators, and having significant economic and social benefits. Attached Figure Description

[0025] Figure 1This is a schematic diagram of the internal structure of a reflux control valve for slowly releasing the reverse torque energy of the polished rod in a screw pump well, according to this utility model.

[0026] Figure 2 This is a top view of the structure of this utility model.

[0027] Figure 3 This is a schematic diagram showing the cooperation between the valve ball and the limiting rod in this utility model.

[0028] Figure 4 This is a schematic diagram of the external structure of this utility model.

[0029] In the diagram: 1. Upper connector; 2. Oil inlet; 3. Valve cover; 4. Valve ball; 5. Valve ball seat; 6. Return hole; 7. Limit rod; 8. Lower connector; 9. Sliding hole; 10. Valve body. Detailed Implementation

[0030] The technical solutions of the present 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 the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0031] Example 1:

[0032] Please see Figures 1 to 4 The present invention provides a reflux control valve for slowly releasing the reverse torque energy of the polished rod of a screw pump well, comprising a valve body 10 and a valve ball 4. The valve body 10 is provided with a valve cover 3 and a valve ball seat 6. The valve cover 3 is provided with an oil inlet hole 2. A limiting rod 7 is provided at one end of the valve cover 3 near the valve ball seat 6. The limiting rod 7 is axially through. The valve ball 4 is provided with a through sliding hole 9. The sliding hole 9 is slidably sleeved on the limiting rod 7. When the valve ball 4 and the valve ball seat 6 are seated and sealed, the valve ball 4 does not disengage from the limiting rod 7.

[0033] Specifically, the valve body 10 is separated from the valve cover 3 and the valve ball seat 6 by a pipe thread joint structure, which facilitates the installation of the valve ball 4.

[0034] Specifically, the valve ball 4, the sliding hole 9, the limiting rod 7, and the valve ball seat 6 are coaxial. Preferably, the limiting rod 7 is located at the center of the valve cover 3.

[0035] Furthermore, the upper end of the valve body 10 is provided with an upper connector 1, and the inner wall of the upper end of the upper connector 1 is provided with a pipe thread for threaded connection with the upper screw pump barrel; the lower end of the valve body 10 is provided with a lower connector 8, and the outer wall of the lower end of the lower connector 8 is provided with a pipe thread for threaded connection with the lower tail pipe.

[0036] Furthermore, the valve cover 3 is fixed inside the valve body 10. The valve cover 3 is plate-shaped, and at least two oil inlet holes 2 are evenly distributed around the circumference of the valve cover 3 to allow oil to pass through smoothly.

[0037] Furthermore, the valve ball 4 is a solid sphere, and the valve ball 4 has a sliding hole 9 passing through the center of the ball.

[0038] Furthermore, the limiting rod 7 is a round tube rod, which is set in the center of the valve cover 3 and inserted into the sliding hole 9 of the valve ball 4. The two work together to limit the movement trajectory of the valve ball 4, so that it can only move vertically up and down along the limiting rod 7, while preventing the valve ball 4 from being worn and damaged due to friction between the valve ball 4 and the inner cavity of the control valve.

[0039] The reflux hole 6 is an axial circular hole channel of the limiting rod 7 circular tube structure, used to reflux and depressurize the well fluid in the upper part of the oil well string into the annular space of the oil casing.

[0040] Furthermore, the valve ball seat 5 is sized to match the valve ball 4. When the valve ball 4 falls into the valve ball seat 5, it plays a sealing role, preventing the well fluid in the upper part of the tubing from flowing back uncontrollably into the annular space of the tubing. The upper edge of the valve ball seat 5 is a conical or arc-shaped surface, which is used to guide the valve ball 4.

[0041] In use, the device is installed and connected to the lower end of the stator of the screw pump well via the upper connector 1, and the lower connector 8 connects to the inlet screen pipe, tail pipe, and plug. During normal production, the well fluid in the annular space of the screw pump well enters the device through the screen pipe. Under the pressure at the bottom of the well, the valve ball 4 moves upward along the limit rod 7 and separates from the valve ball seat 5. The ball and ball seat do not provide a sealing function. The well fluid enters the screw pump stator through the inlet port 2. The rotation of the stator and rotor transfers mechanical energy to the well fluid, which is then lifted through the tubing to the wellhead to achieve well fluid production.

[0042] After the screw pump stops, the pressure inside the tubing exceeds the fluid column pressure in the annular space between the tubing and casing. The well fluid in the tubing flows back, creating a motor effect on the screw pump rotor. The rotor reverses, causing the rod to reverse as well. At this point, the device comes into play. The fluid column pressure in the tubing pushes the valve ball 4 downwards along the limiting rod 7, forming a seal with the valve ball seat. The well fluid in the tubing can only enter the annular space between the tubing and casing through the return hole 6. The throttling effect of the return hole increases the pressure difference between the tubing and casing, causing the well fluid pressure in the tubing to release slowly until the pressures reach equilibrium. Because the well fluid return velocity is limited, the pressure difference between the tubing and casing gradually decreases, reducing the driving force of the screw pump rotor's motor effect. This, in turn, controls the rod to reverse at a suitable safe speed, achieving a slow and safe release of the reverse rotation.

[0043] This invention does not involve installing or altering the ground braking system to force the polished rod to reverse. Instead, it identifies the root cause of the high-speed reverse rotation of the polished rod in the screw pump well and installs a flow-limiting control valve under the pump to slowly release the power source causing the polished rod to reverse, allowing the screw pump well to operate under safe and controllable conditions, thus achieving convenient, fast, and safe construction operations.

[0044] This utility model is available in various models based on the diameter of the return hole. Different models of control valves can be selected according to the physical properties of the oil well and the production pressure difference, so that the flow rate of the well fluid returning from the tubing to the annular space of the casing can be controlled, thereby effectively controlling the rotation speed of the downhole rod string and fundamentally preventing the high-speed reverse rotation of the polished rod.

[0045] This utility model features a separate structure design for the valve ball and valve ball cover, which improves the processing quality and service life of the valve ball and valve ball seat, ensuring the device's flexibility and reliability. It also facilitates assembly, improves assembly quality, and achieves effective sealing between the valve ball and valve ball seat. The design incorporates a dual-function vertical reflux hole and oil inlet hole, which not only seals with the valve ball seat to prevent large flow of well fluid but also uses the reflux hole to control the flow of oil.

[0046] Example 2:

[0047] Based on Example 1, this example provides a set of key parameters for the device, wherein the valve cover 3 has 6 oil inlet holes 2 with a diameter of 16mm evenly distributed around its circumference.

[0048] The valve ball 4 is a solid sphere with a diameter of 50 mm and a sliding hole 9 with a diameter of 15 mm in the center. The limiting rod 7 is a round tube rod with a length of 70 mm.

[0049] The return hole 6 is an 8mm diameter circular channel axially extending from the limiting rod 7.

[0050] All components not discussed in detail in this application, as well as the connection methods of these components, are well-known technologies in this field. They can be directly applied and will not be elaborated further.

[0051] In this utility model, the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0052] In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0053] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0054] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A reflux control valve for slowly releasing the reverse torque energy of a screw pump well's polished rod, comprising a valve body and a valve ball, wherein a valve cover and a valve ball seat are disposed inside the valve body, and the valve cover is provided with an oil inlet hole, characterized in that, A limiting rod is provided near the valve ball seat of the valve cover, and the limiting rod extends axially through the valve. The valve ball is provided with a through sliding hole, which is slidably sleeved on the limiting rod. When the valve ball and the valve ball seat are seated and sealed, the valve ball does not detach from the limiting rod.

2. The reflux control valve for slowly releasing the reverse torque energy of the polished rod in a screw pump well according to claim 1, characterized in that, The limiting rod is a circular tube rod.

3. The reflux control valve for slowly releasing the reverse torque energy of the polished rod in a screw pump well according to claim 1, characterized in that, The valve ball is a solid sphere with a sliding hole passing through its center. The sliding hole, the limiting rod, and the valve ball seat are coaxial.

4. The reflux control valve for slowly releasing the reverse torque energy of the polished rod in a screw pump well according to claim 1, characterized in that, The valve cover is plate-shaped, and at least two oil inlet holes are evenly distributed around its circumference.

5. The reflux control valve for slowly releasing the reverse torque energy of the polished rod in a screw pump well according to claim 1, characterized in that, The upper edge of the valve ball seat is a conical or arc-shaped surface.

6. The reflux control valve for slowly releasing the reverse torque energy of the polished rod in a screw pump well according to claim 1, characterized in that, The valve body is separated from the valve cover and the valve ball seat by a pipe thread joint structure.

7. The reflux control valve for slowly releasing the reverse torque energy of the polished rod in a screw pump well according to claim 1, characterized in that, The valve body is provided with an upper connector at its upper end, and the upper inner wall of the upper connector is provided with a pipe thread; The lower end of the valve body is provided with a lower connector, and the outer wall of the lower end of the lower connector is provided with a pipe thread.

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