Non-contact oil well polished rod break-off blowout prevention device

Abstract

The utility model discloses a non -contact oil well polished rod broken and prevents the device of spouting, it includes the outer tube of being equipped with the blowout prevention channel, the outer end of blowout prevention channel is connected side gland and is equipped with the sealing ball and spring in it, the upper end one side of the center tube of being equipped with ball seat's upper cover plate below that is hung through the pin shaft in the lower surface of the two sides respectively and is located in the outer tube of being equipped with the ball groove and permanent magnet, the polished rod of center tube passes through the hole and is concentric with polished rod channel and the body of ball groove below is supported on the outside of blowout prevention channel, and the upper end of outer tube is equipped with upper gland, when the polished rod falls into the well, and center tube is along the pin shaft and turns down, and sealing ball can enter center tube from ball groove and be pushed up in ball seat in well fluid. The device is compact in structure, and the volume is small, and the installation space range that needs is small, can be adapted to all oil well that has installed wellhead packing box or polished rod seal ware through changing the connection mode of outer tube lower extreme and wellhead packing box, avoids the oil and gas leakage accident in well, and protects the environment.

Description

Technical Field

[0001] This utility model relates to a blowout prevention device for the broken polished rod of an oilfield pumping unit, specifically a non-contact blowout prevention device for the broken polished rod of an oil well. Background Technology

[0002] In oilfield production operations, the beam pumping unit is the most widely used surface oil production equipment. It extracts crude oil by driving the sucker rod and the piston of the deep well pump through the reciprocating motion of the polished rod. During normal operation, the polished rod engages with the packing in the polished rod sealing box, or wellhead packing box, at the wellhead to prevent oil and gas leakage. However, the polished rod is prone to fatigue and breakage under long-term alternating loads. When the polished rod breaks off and falls below the packing box, oil and gas will rush out through the packing box, causing oil and gas ejection and backflow of crude oil in the gathering pipeline, resulting in environmental pollution at the well site and posing safety hazards.

[0003] To prevent the serious consequences of polished rod breakage, two common measures are currently employed in production sites: First, a check valve is installed in the wellhead process to reduce contamination from crude oil backflow in the gathering pipeline. However, the valve core of the check valve installed in the wellhead process is constantly immersed in crude oil, and its valve seat is prone to impurities adhering to it, leading to valve ball seal failure. If a polished rod breakage and fall into the well occurs, it cannot completely prevent crude oil leakage from the wellhead process. Second, a spring-loaded ball anti-breakage device is installed on the packing box to achieve self-sealing and blowout prevention after polished rod breakage. However, during the operation of the pumping unit, this spring-loaded ball anti-breakage device suffers from friction between the valve ball and the polished rod due to the ball pressing against it, causing the valve ball to deform and the seal to fail. Simultaneously, wear damages the coating on the polished rod surface and creates burrs, shortening the service life of the polished rod and the packing in the wellhead sealing box.

[0004] To address the aforementioned issues, the following related patent technology has emerged: Patent application number CN202421136330.9 discloses an oil well polished rod breakage and blowout prevention device, comprising a sleeve body with an upper casing and a lower casing arranged opposite to each other, forming a polished rod channel between the upper casing, the lower casing, and the sleeve body. A front end cap is provided in front of the sleeve body, and a rear end cap is provided behind the sleeve body. A horizontal moving block is provided inside the sleeve body, a sealing groove is provided above the horizontal moving block, a vertical top spring is provided in the sealing groove, a sealing plug is provided at the upper end of the vertical top spring, a transverse top spring is provided between the rear end cap and the horizontal moving block, a pulley groove is provided in front of the horizontal moving block, and a pulley is provided in the pulley groove.

[0005] However, the triggering device in the above invention is a pulley. During operation, the pulley comes into contact with the polished rod, which may damage the protective coating on the surface of the polished rod and accelerate its corrosion and wear. Furthermore, the pulley needs to be replaced after it wears out. If it is not replaced in time, it will cause friction between the metal parts and the polished rod. Even after the polished rod is damaged, it can still lead to oil and gas leakage.

[0006] Patent application CN202421841209.6 discloses a self-sealing device for preventing blowouts in oil and gas extraction rods. The device includes a main body with a cavity containing multiple isolation balls. A port is located at the top of the main body, and a gland is placed within the port. A pressure cap is fitted onto the port, with the lower inner wall of the pressure cap abutting against the top wall of the gland. A packing box connecting cap is located at the bottom of the main body. Three holes of the same diameter and coaxiality, namely, a first hole, a second hole, and a third hole, are vertically formed on the top wall of the pressure cap, the gland body, and the packing box connecting cap to accommodate the polished rod. The principle is that multiple isolation balls are placed within the cavity of the main body, and the upward movement of liquid pushes the isolation balls to the pressure cap to achieve a seal.

[0007] However, the cooperative sealing reliability of the isolation ball in the above-mentioned device is poor, the partition and limiting structure require frequent maintenance, and the adaptability and ease of maintenance are limited.

[0008] Patent application CN201120304804.2 discloses a blowout preventer for wellheads where polished rod breaks off, applied to oilfield wellhead blowout prevention. A wellhead sealer housing is welded and fixed to the lower part of the packing box. Inside the wellhead sealer housing, a lower partition, a lower partition, and an upper partition are welded and fixed. An upwardly inclined tube is welded to the wellhead sealer housing, positioned between the lower and upper partitions. A rubber ball is located between the lower and upper partitions. A second rubber ball is located inside the inclined tube, and a compression spring is located above the second rubber ball and inside the inclined tube. A pressure cap is threaded and fixed to the end of the inclined tube. The effect is that after the polished rod breaks off and falls into the well, the rubber ball, under the pressure of oil and gas, pushes against the upper partition inside the packing box, providing a seal and preventing the oil and gas mixture from ejecting.

[0009] However, during normal production, the rubber ball is always in contact with the polished rod. The rubber ball wears a lot and is easily deformed, which cannot seal the polished rod passage hole in the upper partition well, and there is still a possibility of oil and gas leakage.

[0010] Currently, there is no effective solution to the problem of seal failure caused by the valve ball contacting the polished rod in the blowout preventer (BOP) for broken polished rod, which seriously affects the safe and stable production of oil wells. In conclusion, the BOP for the polished rod at the pumping unit wellhead still needs improvement. Summary of the Invention

[0011] The purpose of this invention is to provide a non-contact blowout preventer for polished rod breakage in oil wells, used to prevent oil and gas leakage after polished rod breakage in beam pumping units. It solves the problems of existing polished rod breakage blowout preventers, such as seal failure due to friction between the valve ball and the polished rod, polished rod damage, and oil leakage caused by poor sealing of the check valve in the wellhead process when polished rod breakage occurs. This invention achieves effective blowout prevention at the wellhead after polished rod breakage and avoids oil and gas leakage in the wellhead process, ensuring the safe and stable operation of the oil well. It also protects the environment and improves the economic efficiency of the oil well.

[0012] The technical solution of this utility model is: a non-contact blowout preventer for polished rod breakage in oil wells, comprising an outer cylinder with a blowout preventer channel, the outer end of which is connected to a side pressure cap and contains a sealing ball and a spring; wherein: the upper end of a central cylinder with ball grooves and permanent magnets on both sides is suspended by a pin under an upper cover plate with a ball seat and located in the outer cylinder; the polished rod of the central cylinder is concentric with the polished rod channel through a hole, and the body below the ball groove rests against the outside of the blowout preventer channel; an upper pressure cap is installed at the upper end of the outer cylinder; the central cylinder, made of lightweight non-magnetic material, does not contact the polished rod, and the polished rod can pass through the outer cylinder, the central cylinder, the upper cover plate, and the upper pressure cap; when the polished rod falls into the well and the central cylinder flips down along the pin, the sealing ball can enter the central cylinder from the ball groove and be pushed up by the well fluid to sit in the ball seat.

[0013] Preferably, the ball-in-the-hole groove is a U-shaped groove with a rounded bottom and a vertical groove, and the width of the groove is greater than the diameter of the sealing ball; the adsorption force of the permanent magnet is greater than the elastic force of the spring in the blowout preventer channel, and during normal operation of the light rod, the bottom of the ball-in-the-hole groove in the central cylinder is higher than the bottom of the blowout preventer channel.

[0014] Preferably, a socket is provided at the upper end of the central cylinder corresponding to the ball groove, and the socket is provided with a pin hole that matches the outer diameter of the pin; the lower end of the central cylinder is an inclined surface, and the cylinder body on the ball groove side is 5mm-8mm shorter than the cylinder body on the side where the permanent magnet is installed.

[0015] Preferably, the central cylinder is made of aluminum alloy or engineering plastic; the permanent magnet is installed in the assembly groove of the central cylinder opposite to the ball groove, and an inner baffle is provided at the bottom of the assembly groove near the guide rod, and the permanent magnet is fixed in the inner baffle by fixing pins and magnet blocks.

[0016] Preferably, the permanent magnet is made of samarium cobalt permanent magnet material, the magnet block is made of stainless steel, and the central cylinder is made of alloy steel material.

[0017] Preferably, the polished rod channel in the outer cylinder is offset within the main channel of the mounting center cylinder, and the inner diameter of the polished rod channel matches the outer diameter of the polished rod in the oil well. The upper outer circumference of the outer cylinder is provided with external threads and can be threadedly connected to the upper pressure cap, and the lower cavity of the outer cylinder is provided with internal threads and can be threadedly connected to the wellhead packing box. The blowout preventer channel in the outer cylinder is obliquely positioned to the main channel, and the upward oblique angle between the blowout preventer channel and the main channel in the outer cylinder is set between 60 and 80 degrees.

[0018] Preferably, the upper end of the outer cylinder is a cover plate mounting cavity, and the cover plate mounting cavity is provided with cover plate slots that match the shape and number of the locking blocks in the cover plate. A sealing ring is provided at the bottom of the cover plate mounting cavity.

[0019] Preferably, the upper cover plate is circular in shape and has one or more locking blocks on the outer circle. The locking blocks are arc-shaped blocks that can be inserted into the upper cover plate slots in the outer cylinder.

[0020] Preferably, the upper cover plate has an offset light rod passage hole in its body and a ball seat is provided at the lower end of the light rod passage hole. The ball seat is a conical cavity with a smaller upper diameter and a larger lower diameter, and the inner diameter of the smaller diameter end is smaller than the outer diameter of the sealing ball.

[0021] Preferably, the through hole of the light rod in the upper cover plate is concentric with the through hole of the light rod in the central cylinder and the light rod channel in the outer cylinder, and the inner diameter of each is larger than the outer diameter of the light rod; two fixing blocks with pin holes are fixed at the lower outer edge of the ball seat, corresponding to the socket in the central cylinder; a socket can be installed between the two fixing blocks, and the pin can be inserted into the pin holes in the two fixing blocks and the socket to suspend the central cylinder in the outer cylinder.

[0022] Compared with existing bare-pole blowout preventers, the significant advantages of this invention are as follows:

[0023] The central cylinder of this invention is provided with ball grooves and permanent magnets on both sides. The central cylinder is made of lightweight non-magnetic material, which is lightweight and high-strength. The permanent magnet installed on one side has an attraction force on the light rod passing through it, and the attraction force is greater than the elastic force of the spring on the sealing ball, so that the central cylinder suspended on one side of the lower end of the upper cover plate and the light rod are always on the same center line, while the central cylinder does not contact the light rod.

[0024] In this invention, the through hole of the smooth rod on the upper cover plate, the through hole of the smooth rod in the central cylinder, and the channel of the smooth rod in the outer cylinder are concentric, and their inner diameters are all larger than the outer diameter of the smooth rod. The through hole and the channel are offset within the upper cover plate and the outer cylinder, respectively. The central cylinder, suspended from the lower end of the upper cover plate by a pin, is also offset within the outer cylinder, and its through hole is concentric with the through hole and the channel, with its inner diameter being larger than the outer diameter of the smooth rod. The channel, through hole, and through hole do not contact the smooth rod. Because the sealing ball is blocked by the central cylinder, it cannot enter the central cylinder, achieving contactless operation of the smooth rod with the device during production, thus avoiding wear on the smooth rod.

[0025] 3. After the polished rod is lowered into the well, the central cylinder, which is suspended and offset in the outer cylinder and is made of lightweight non-magnetic material, loses its attraction to the polished rod due to the permanent magnet installed in it. The central cylinder will quickly flip to the left and down along the pin axis, allowing the sealing ball to enter its ball groove. Driven by the oil and gas in the well, it will immediately rise to the ball seat and sit in the ball seat, sealing the leakage channels of oil, gas and water in the well.

[0026] 4. The blowout preventer channel in this device is offset from the main channel and tilted upwards, allowing the sealing ball to quickly move down into the central cylinder and sit stably in the ball seat at the lower end of the upper cover plate, thus closing the leakage channels of oil, gas and water in the well.

[0027] 5. This utility model employs a magnetic limiting design, using a permanent magnet and an upper cover plate to limit the center cylinder, preventing friction between the center cylinder and the guide rod. By utilizing the loss of magnetic attraction between the permanent magnet and the guide rod, the center cylinder is triggered to tilt downwards, significantly improving the anti-spray response speed and operational reliability of this device.

[0028] 6. This device has a compact structure and small size, requiring little installation space. By changing the connection method between the lower end of the outer cylinder and the wellhead packing box, it can be adapted to all oil wells that have installed wellhead packing boxes or polished rod seals, with an adaptation rate of over 90%.

[0029] 7. Experiments have shown that this device instantly self-seales after the polished rod breaks off. Simulation tests show that the self-sealing response time is less than 1 second. Compared with existing devices, oil and gas leakage is reduced by more than 95%. Simultaneously, this device avoids friction between the sealing ball and the polished rod, as well as between the central cylinder and the polished rod. Experimental verification shows that the service life of the polished rod can be extended by more than 3 times, and the packing replacement cycle can be extended by more than 2 times. Furthermore, this invention has a simple structure, requiring only 2-3 people for installation and replacement, taking approximately 30 minutes, thus improving installation efficiency by 50% compared to traditional devices.

[0030] 8. This device operates reliably under various downhole pressure environments, with a success rate exceeding 99%. It is suitable for wellhead blowout prevention in beam pumping units, effectively ensuring safe production even when the polished rod breaks off. It prevents oil and gas leaks from the well, protecting the environment while significantly reducing the workload for workers, demonstrating significant effectiveness and generating substantial economic benefits. Attached Figure Description

[0031] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a cross-sectional view of the structural schematic diagram of this utility model.

[0032] Figure 2 yes Figure 1 A schematic diagram of the external structure of the inner and outer cylinders.

[0033] Figure 3 yes Figure 2 Cross-sectional view.

[0034] Figure 4 yes Figure 3 Top view.

[0035] Figure 5 yes Figure 1 A schematic diagram of the external structure of the central cylinder.

[0036] Figure 6 yes Figure 5 Cross-sectional view.

[0037] Figure 7 yes Figure 1 A schematic diagram of the upper and middle cover plates.

[0038] In the diagram: 1. Smooth rod; 2. Outer cylinder; 2. Smooth rod channel; 2-1. Blowout channel; 2-2. Upper cover plate slot; 2-3. Sealing ring; 2-4. Permanent magnet; 3. Center cylinder; 4. Socket; 4-1. Smooth rod through hole; 4-2. Ball slot; 4-3. Magnet stop; 5. Pin; 6. Upper cover plate; 6-1. Locking block; 6-2. Ball seat; 6-3. Fixing block; 7. Upper pressure cover; 8. Sealing ball; 9. Spring; 10. Side pressure cover. Detailed Implementation

[0039] The accompanying drawings are for reference and illustration only and are not intended to limit the scope of protection of this utility model. The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0040] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model 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 of the present utility model and are not intended to limit the present utility model.

[0041] In the description of this utility model, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model 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 this utility model. Furthermore, in the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0042] See Figures 1-7 A non-contact blowout preventer for polished rod breakage in oil wells includes an outer cylinder 2 with a blowout preventer channel 2-2. The outer end of the blowout preventer channel 2-2 is connected to a side pressure cap 10, which contains a sealing ball 8 and a spring 9. The upper end of a central cylinder 4, which has a ball groove 4-3 and a permanent magnet 3 on both sides, is suspended by a pin 5 below an upper cover plate 6 with a ball seat 6-2 and is located in the outer cylinder 2. The polished rod of the central cylinder 4 is concentric with the polished rod channel 2-1 through the hole 4-2 and the body below the ball groove 4-3 rests against the outside of the blowout preventer channel 2-2. An upper pressure cap 7 is installed at the upper end of the outer cylinder 2. The central cylinder 4, made of lightweight non-magnetic material, does not contact the polished rod 1. The polished rod 1 can pass through the outer cylinder 2, the central cylinder 4, the upper cover plate 6, and the upper pressure cap 7. When the polished rod 1 falls into the well and the central cylinder 4 flips down along the pin 5, the sealing ball 8 can enter the central cylinder 4 from the ball groove 4-3 and be pushed up by the well fluid to sit in the ball seat 6-2.

[0043] In this invention, a permanent magnet 3 is installed on one side of the central cylinder 4 made of lightweight non-magnetic material, while the body on the other side, which has a ball-inlet groove 4-3, rests against the outside of the blowout preventer channel 2-2. The sealing ball 8 cannot enter the ball-inlet groove 4-3 of the central cylinder 4, so that the sealing ball 8 cannot contact the light rod 1 and will not cause wear to the light rod 1. On the other hand, the permanent magnet 3 installed on the other side of the central cylinder 4 has an adsorption effect on the light rod 1, which can give the central cylinder 4 a force towards the sealing ball 8. This can keep the position of the central cylinder 4, which is suspended in the outer cylinder 2 by the pin 5 at one end, fixed and maintain a certain distance from the light rod 1, and will not wear the light rod 1.

[0044] When the polished rod 1 breaks off and falls into the well, the central cylinder 4, made of lightweight non-magnetic material, is suspended at one end by a pin 5 under the upper cover plate 6 inside the outer cylinder 2. After the polished rod 1 breaks off and falls into the well, the central cylinder 4 will naturally tilt downwards along the pin 5 under the weight of the permanent magnet 3. The sealing ball 8, pushed by the spring 9, enters the polished rod passage hole 4-2 from the ball groove 4-3. It is then pushed upwards by the well fluid flowing out of the well into the ball seat 6-2 of the upper cover plate 6, sealing the device and preventing the well fluid from flowing out. This prevents oil and gas leakage accidents from occurring in the wellhead packing box and wellhead flow after the polished rod 1 breaks off and falls into the well. This protects the environment and improves the economic efficiency of the oil well; at the same time, the blowout preventer does not contact the polished rod 1, extending the service life of the polished rod 1 and the packing, and reducing production and maintenance costs.

[0045] Based on the above embodiment one, the present invention also has the following embodiments:

[0046] In a preferred embodiment: the ball-inlet groove 4-3 is a U-shaped groove with a rounded bottom and a vertical groove, and the groove width is greater than the diameter of the sealing ball 8; the attraction force of the permanent magnet 3 is greater than the elastic force of the spring 9 in the blowout preventer channel 2-2. During normal operation of the polished rod 1, the bottom of the ball-inlet groove 4-3 in the central cylinder 4 is higher than the bottom of the blowout preventer channel 2-2. During normal operation of the polished rod 1, due to the attraction force of the permanent magnet 3 on the polished rod 1, the body of the central cylinder 4 is blocked above the bottom of the blowout preventer channel 2-2, and the sealing ball 8 cannot move. When the polished rod 1 is lowered into the well, the central cylinder 4 moves along the pin shaft 5 towards... Figure 1 The left side of the ball flips down and makes way, allowing the sealing ball 8 to easily enter the ball groove 4-3, effectively preventing oil and gas leakage.

[0047] In a preferred embodiment, a socket 4-1 is provided at the upper end of the central cylinder 4 corresponding to the ball groove 4-3. The socket 4-1 has a pin hole that matches the outer diameter of the pin 5. The lower end of the central cylinder 4 is sloped, and the cylinder body on the side of the ball groove 4-3 is 5mm-8mm shorter than the cylinder body on the side where the permanent magnet 3 is installed. This design reduces the overall height of the device. Alternatively, if the lower end of the central cylinder 4 is not sloped, the height of the outer cylinder 2 below the blowout preventer 2-2 can be increased. This accommodates the height required for the central cylinder 4 to tilt downwards within the outer cylinder 2 after the polished rod 1 breaks off and falls into the well.

[0048] In a preferred embodiment: the central cylinder 4 is made of aluminum alloy or engineering plastic; the permanent magnet 3 is installed in the assembly groove of the central cylinder 4 opposite to the ball groove 4-3 and an inner retaining edge is provided at the bottom of the groove near the light rod 1; the permanent magnet 3 is fixed in the inner retaining edge by fixing pins and magnet blocks 4-4.

[0049] In a preferred embodiment: the permanent magnet 3 is made of samarium cobalt permanent magnet material, the magnet stop 4-4 is made of stainless steel, and the central cylinder 4 is made of alloy steel material, such as chromium steel, chromium-nickel steel, and stainless steel. The aforementioned lightweight non-magnetic materials are lightweight and high-strength. When the polished rod 1 is lowered into the well, the central cylinder 4 loses the attraction between the permanent magnet 3 and the polished rod 1. It reacts rapidly; under the action of the permanent magnet 3, its own weight, and the effect of unilateral suspension, it immediately flips downwards along the pin 5, allowing the sealing ball 8 to enter the ball groove 4-3 and be pushed by the rising well fluid to the ball seat 6-2 of the upper cover plate 6, quickly sealing the channel through which the well fluid flows out.

[0050] In a preferred embodiment: the polished rod channel 2-1 in the outer cylinder 2 is offset within the main channel of the mounting center cylinder 4, and the inner diameter of the polished rod channel 2-1 matches the outer diameter of the polished rod 1 in the installed oil well; the upper outer circumference of the outer cylinder 2 is provided with external threads and can be threadedly connected to the upper pressure cap 7, and the lower cavity of the outer cylinder 2 is provided with internal threads and can be threadedly connected to the wellhead packing box; the blowout preventer channel 2-2 in the outer cylinder 2 is obliquely positioned to the main channel, and the upward oblique angle between the blowout preventer channel 2-2 and the main channel in the outer cylinder 2 is set between 60 and 80 degrees. By changing the connection method between the lower end of the outer cylinder 2 and the wellhead packing box, it can be adapted to all oil wells that have installed wellhead packing boxes or polished rod seals.

[0051] In a preferred embodiment: the upper end of the outer cylinder 2 is a cover plate mounting cavity, and the cover plate mounting cavity is provided with cover plate slots 2-3 that match the shape and number of the locking blocks 6-1 in the cover plate 6. A sealing ring 2-4 is provided at the bottom of the cover plate mounting cavity. This achieves a seal between the outer cylinder 2 and the cover plate 6.

[0052] In a preferred embodiment, the upper cover plate 6 is generally circular and has one or more locking blocks 6-1 on its outer circle. The locking blocks 6-1 are arc-shaped blocks and can be inserted into the upper cover plate slots 2-3 in the outer cylinder 2.

[0053] In a preferred embodiment: the upper cover plate 6 has an offset light rod through hole in its body and a ball seat 6-2 is provided at the lower end of the light rod through hole. The ball seat 6-2 is a conical cavity with a smaller upper diameter and a larger lower diameter, and the inner diameter of the smaller diameter end is smaller than the outer diameter of the sealing ball 8.

[0054] In a preferred embodiment: the through hole of the polished rod in the upper cover plate 6 is concentric with the through hole 4-2 of the polished rod in the central cylinder 4 and the polished rod channel 2-1 in the outer cylinder 2, and the inner diameter of each is larger than the outer diameter of the polished rod 1; two fixing blocks 6-3 with pin holes are fixed at the lower outer edge of the ball seat 6-2, corresponding to the socket 4-1 in the central cylinder 4; the socket 4-1 can be inserted between the two fixing blocks 6-3, and the pin 5 can pass through the pin holes in the two fixing blocks 6-3 and the socket 4-1, suspending the central cylinder 4 in the outer cylinder 2. When the polished rod 1 is lowered into the well, the central cylinder 4 will quickly flip to the left and down along the pin 5, allowing the sealing ball 8 to enter the ball groove 4-3, and immediately rise to the ball seat 6-2 under the push of the oil and gas in the well and sit in the ball seat 6-2, sealing the leakage channels of oil, gas and water in the well.

[0055] 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. A non-contact blowout preventer for polished rod breakage in oil wells, comprising an outer cylinder with a blowout preventer channel, the outer end of which is connected to a side pressure cap and contains a sealing ball and a spring, characterized in that... The upper end of the central cylinder, which has ball grooves and permanent magnets on both sides, is suspended by a pin under the upper cover plate with a ball seat and is located in the outer cylinder. The polished rod of the central cylinder is concentric with the polished rod channel through the hole, and the body below the ball groove rests against the outside of the blowout preventer channel. The upper end of the outer cylinder is equipped with an upper pressure cap. The central cylinder, made of lightweight non-magnetic material, does not contact the polished rod. The polished rod can pass through the outer cylinder, the central cylinder, the upper cover plate, and the upper pressure cap. When the polished rod is lowered into the well and the central cylinder flips down along the pin, the sealing ball can enter the central cylinder from the ball groove and be pushed up by the well fluid to sit in the ball seat.

2. The non-contact blowout preventer for polished rod breakage in oil wells as described in claim 1, characterized in that, The ball-in-the-hole groove is a U-shaped groove with a rounded bottom and a vertical groove, and the width of the groove is greater than the diameter of the sealing ball; the attraction force of the permanent magnet is greater than the elastic force of the spring in the blowout preventer channel, and during normal operation of the smooth rod, the bottom of the ball-in-the-hole groove in the central cylinder is higher than the bottom of the blowout preventer channel.

3. A non-contact blowout preventer for oil well polished rod breakage as described in claim 2, characterized in that, in The upper end of the central cylinder corresponding to the ball groove is provided with a socket, which has a pin hole that matches the outer diameter of the pin; the lower end of the central cylinder is a slope, and the cylinder body on the ball groove side is 5mm-8mm shorter than the cylinder body on the side where the permanent magnet is installed.

4. A non-contact blowout preventer for polished rod breakage in oil wells as described in claim 3, characterized in that, The central cylinder is made of aluminum alloy or engineering plastic; the permanent magnet is installed in the assembly groove of the central cylinder opposite to the ball groove, and an inner baffle is provided at the bottom of the assembly groove near the light rod. The permanent magnet is fixed in the inner baffle by fixing pins and magnetic blocks.

5. A non-contact blowout prevention device for polished rod breakage in oil wells as described in claim 4, characterized in that, The permanent magnet is made of samarium cobalt permanent magnet material, the magnet block is made of stainless steel, and the central cylinder is made of alloy steel material.

6. A non-contact blowout preventer for polished rod breakage in oil wells as described in claim 3, characterized in that, The polished rod channel in the outer cylinder is offset within the main channel of the mounting center cylinder, and the inner diameter of the polished rod channel matches the outer diameter of the polished rod in the oil well. The upper outer circumference of the outer cylinder is provided with external threads and can be threadedly connected to the upper pressure cap, while the lower cavity of the outer cylinder is provided with internal threads and can be threadedly connected to the wellhead packing box. The blowout preventer channel in the outer cylinder is obliquely positioned to the main channel, and the upward oblique angle between the blowout preventer channel and the main channel in the outer cylinder is set between 60 and 80 degrees.

7. A non-contact blowout preventer for polished rod breakage in oil wells as described in claim 6, characterized in that, The upper end of the outer cylinder is a cover plate mounting cavity, and a cover plate slot is provided in the cover plate mounting cavity that matches the shape and number of the locking blocks in the cover plate. A sealing ring is provided at the bottom of the cover plate mounting cavity.

8. A non-contact blowout preventer for polished rod breakage in oil wells as described in claim 7, characterized in that, The upper cover plate is circular in shape and has one or more locking blocks on the outer circle. The locking blocks are arc-shaped blocks that can be inserted into the upper cover plate slots in the outer cylinder.

9. A non-contact blowout preventer for polished rod breakage in oil wells as described in claim 7 or 8, characterized in that, The upper cover plate has an offset light rod passage hole in its body and a ball seat is provided at the lower end of the light rod passage hole. The ball seat is a conical cavity with a smaller upper diameter and a larger lower diameter, and the inner diameter of the smaller diameter end is smaller than the outer diameter of the sealing ball.

10. A non-contact blowout prevention device for polished rod breakage in oil wells as described in claim 9, characterized in that, The through hole of the light rod in the upper cover plate is concentric with the through hole of the light rod in the central cylinder and the light rod channel in the outer cylinder, and the inner diameter of both is larger than the outer diameter of the light rod; two fixing blocks with pin holes are fixed at the lower outer edge of the ball seat, corresponding to the socket in the central cylinder; a socket can be installed between the two fixing blocks, and the pin can be inserted into the pin holes in the two fixing blocks and the socket to suspend the central cylinder in the outer cylinder.

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