A switchable retrievable tubing plug

Abstract

The utility model belongs to oil well oil pipe block and anti -blowout equipment technical field relates to a switch can retreat type oil pipe stopper, including down moving subassembly, seat seal subassembly, switch subassembly, realizes downlink, plugging and deblocking through liquid pressure drive in oil pipe. Switch subassembly includes slip bowl, slip, slip connecting sleeve, damping ring, limit sliding sleeve, the limit sliding sleeve of stopper is equipped with long slide, short slide and conversion slide, and the multiple switching of slip release and anchoring can be realized in cooperation with limit pin. When using, the stopper is placed into the oil pipe, and the downhole is hit through the pump truck, and the pump is stopped after automatic seat seal, and the pump is stopped after the stopper is pushed again, and the anchoring can be released, and the stopper goes up under the action of downhole pressure, reaches the purpose of withdrawing the stopper. The device is reliable in sealing, reusable, simple to operate, suitable for use in the oil pipe block scene in the downhole under pressure operation, can significantly improve the oilfield operation efficiency, and greatly reduces the oilfield workover cost.

Description

Technical Field

[0001] This utility model belongs to the technical field of plugging and blowout prevention equipment for oil wells, water injection wells, and gas wells, and specifically relates to a switchable retractable tubing plug that does not require retrieval. Background Technology

[0002] With increasing environmental protection and formation protection requirements in oilfields, pressurized operations on oil wells, water injection wells, and gas wells are becoming increasingly common. Tubing plugs are suitable for use in oil wells, gas wells, and water injection wells during pressurized operations, maintenance, pump replacement, logging, perforation, pump running, well workover, and testing. They seal the tubing passages under conditions where well control and blowout prevention are not permitted, protecting the formation, reducing pollution, and improving operational efficiency and safety. The plug, through its expanding rubber sleeve, anchoring structure, and automatic unlocking mechanism, automatically expands and seals under downhole pressure, automatically anchors the slips, and maintains a stable blockage.

[0003] The commonly used pump trucks and high-pressure nitrogen trucks deliver plugs using one-way slips. Although they are efficient, they have the problem of being unable to retrieve the plugs. This can cause serious defects such as water injection wells, gas wells, or oil wells being unable to resume production if the downhole tools get stuck.

[0004] Our company's authorized utility model patent, CN104763371B, discloses a free-sliding oil pipe plug and its usage method. Utilizing the characteristic of an open-threaded locking block that guides the sliding motion, it ensures that the plug's seal is not affected by reduced external pressure. The cooperation of the wedge-shaped sliding column and the sliding block slip achieves anchoring to the inner wall of the oil pipe.

[0005] Our company's authorized utility model patent with publication number CN112343539B discloses a hydraulically deployed steel wire for retrieving oil pipe blockage devices and its usage method. A pawl is installed in the middle of the limiting shaft via a pin. It is deployed by hydraulic power. After the pump pressure rises sharply, the pump stops. When it reaches the bottom and stops, the wellhead valve is opened. The blockage device moves upward under the push of the downhole pressure. Due to the obstruction of the rubber tank at the lower end of the retrieval head, the pawl of the blockage device will be stuck at the oil pipe connection of the coupling. The rubber tube is compressed, and a seat seal is achieved.

[0006] The above two methods can achieve reliable live plugging, but they have two problems:

[0007] 1. The core sealing components are destroyed after the plug is set and unsealed. Specifically, the two are shear pins and pawls respectively. Once the shear pins and pawls are destroyed, the sealing and unsealing operations cannot be performed again. After shallow sealing repair, when further exploration and sealing are required, such as after retrieval, the shear pins and pawls are replaced and then put back into the well for sealing, the work efficiency is low.

[0008] 2. When retrieving the blockage device, special retrieval tools are required, which is a complicated operation.

[0009] Designing a tubing plug that is easier to control and can be used repeatedly and reliably, specifically tailored to the downhole environments of oil wells, gas wells, and water injection wells, has become an urgent problem to be solved. Utility Model Content

[0010] To address the aforementioned shortcomings of existing technologies, this invention aims to solve the problem that the existing tubing plug's locking mechanism is generally disposable. Reuse requires removing the plug from the tubing, replacing the locking structure, and using specialized retrieval tools, making the operation relatively complex and inefficient. The purpose of this invention is to provide a retractable tubing plug that employs an innovative limiting bushing and slip connection structure. By simply controlling the start and stop of the water pump truck or high-pressure nitrogen truck, the plug can be switched on and off, simplifying well sealing and release operations while ensuring reliable sealing. It inherits the advantages of low construction cost and high operational efficiency of existing plugs while overcoming the problem of secondary retrieval associated with other plugs, significantly improving efficiency and reducing operating costs, making it a revolutionary invention.

[0011] To achieve the above objectives, the utility model adopts the following technical solution: a switchable retractable oil pipe plug, comprising a downward moving assembly, a seat seal assembly, and a switching assembly.

[0012] The downward moving component includes a guide head and a glue tower. The guide head is connected to the glue tower. The guide head is provided with a conical structure, and the glue tower is provided with multiple conical glue rings.

[0013] The sealing assembly includes a slanted pusher, an expanding cup, a compressive rubber sleeve, and a rubber sleeve seat. The slanted pusher is sleeved on a central shaft, which is detachably connected to a rubber tower shaft. The rubber tower is fixed on the rubber tower shaft, and the slanted pusher can move on the central shaft. The slanted pusher, expanding cup, and compressive rubber sleeve are sequentially sleeved on the rubber sleeve seat. The slanted pusher has opposing tapered portions at both ends, which can push the lower tapered surface under downhole pressure, thereby causing the upper tapered portion to push the expanding cup open. When the rubber sleeve seat is fixed, the expanding cup can push the compressive rubber sleeve to expand and block the inner wall of the tubing.

[0014] The switching assembly includes a slip seat, slips, a slip connecting sleeve, a damping ring, and a limiting sleeve. The damping ring is mounted on the slip connecting sleeve, which is detachably connected to the rubber sleeve seat. The slips can move on the slip seat and expand or contract inward towards the inner wall of the oil pipe during movement. The slips are movably connected to the slip connecting sleeve, and a limiting pin is installed on the side wall of the slip connecting sleeve. The slip connecting sleeve is mounted outside the limiting sleeve and can move relative to it. The limiting sleeve has recessed long slideways, short slideways, and conversion slideways on its outer side. The long and short slideways are located at the lower part of the limiting sleeve and are spaced apart from each other. The conversion slideway is located at the upper part of the limiting sleeve and is located between the long and short slideways. The long and short slideways are connected by an inclined side, and the center projection of the conversion slideway is located on the inclined side. The limiting pin is inserted into the limiting sleeve. When the limiting pin is at the lowest part of the long slideway, the slips expand to the maximum and are stuck against the inner wall of the oil pipe.

[0015] According to another embodiment of the utility model or any of the foregoing embodiments of the tubing plugger, the expansion cup has a metal sleeve, the rubber sleeve seat is made of metal, and grooves are provided inside the metal sleeve and the rubber sleeve seat, with sealing rings filling the grooves. After the rubber sleeve expands under compression, in order to seal the downhole pressure, sealing rings are provided inside the expansion cups and the rubber sleeve seat on both sides of the compressed rubber sleeve, which can prevent downhole oil or water from passing through the gaps between the rubber sleeve seat and the central shaft, and between the metal sleeve of the expansion cup and the rubber sleeve seat.

[0016] According to another embodiment of the utility model or any of the foregoing embodiments, the oil pipe plugger, wherein the damping ring includes a damping outer ring and a damping inner ring, the damping inner ring is made of metal and is sleeved on the slip connecting sleeve, the damping outer ring is embedded in the groove on the outer surface of the damping inner ring and is made of rubber.

[0017] According to another embodiment of the utility model or any of the foregoing embodiments of the oil pipe plugger, the damping ring has a plurality of liquid flow channels on its outer ring. These liquid flow channels allow liquid to pass through while the damping ring is blocking the slip connecting sleeve, thus pushing the compression cylinder. Preferably, there are multiple liquid flow channels, evenly distributed in a ring shape; for example, the damping outer ring can be spline-shaped. Typically, the inner diameter of the oil pipe is 62 mm, and the outer edge of the damping outer ring is located on a circle with a diameter of 63 mm.

[0018] According to another embodiment of the utility model or any of the foregoing embodiments, the oil pipe plugger has three slips evenly distributed in a ring, and the slip seat also has three guide grooves corresponding to the slips.

[0019] According to another embodiment of the utility model or any of the foregoing embodiments, the oil pipe plugger is provided with a sealing cone surface and a guide groove. A hook is provided at the front of the slip, which is inserted into the through hole at the rear of the slip connecting sleeve. The slip can move in the guide groove of the rubber sleeve. Multiple conical teeth are provided on the outer rear part of the slip, and a sliding cone surface is provided on the inner rear part of the slip to cooperate with the sealing cone surface of the slip seat.

[0020] According to another embodiment of the utility model or any of the foregoing embodiments, the oil pipe plugger is wherein the limiting sleeve is sleeved on the connecting shaft, and the connecting shaft is detachably connected to the slip seat.

[0021] According to another embodiment of the utility model or any of the foregoing embodiments of the oil pipe plug, the lower part of the connecting shaft is provided with an external thread, and the head of the slip seat is provided with an internal thread to lock with the connecting shaft; the slip connecting sleeve and the rubber sleeve seat are connected by threads.

[0022] According to another embodiment of the utility model or any of the foregoing embodiments, the oil pipe plugger is provided with a locking nut at the rear of the connecting shaft, and the locking nut limits the movement of the limiting sleeve.

[0023] According to another embodiment of the utility model or any of the foregoing embodiments, the oil pipe plugger is provided with a countersunk plate and a groove to prevent blockage in the slip connecting sleeve.

[0024] According to another embodiment of the utility model or any of the foregoing embodiments, the oil pipe plugger has two conversion slides and two short slides for the limiting slide sleeve, with adjacent conversion slides or short slides spaced 180 degrees apart, and four conversion slides are provided.

[0025] This invention utilizes liquid pressure to drive the plugger's reciprocating motion within the tubing. By forcibly switching the position of the limiting pin through different slides within the limiting sleeve, it precisely controls the outward expansion and contraction of the slips, enabling the plugger to repeatedly seal and release without relying on one-time mechanisms such as shear pins or ratchet pavers. After the plugger is deployed from the wellhead into the tubing, a pump truck (high-pressure nitrogen truck or water pump truck) injects water into the upper end of the tubing string. A one-way rubber ring is installed at the front guide head; liquid pressure pushes the rubber ring downwards, and the rubber ring generates downward thrust under pressure differential, allowing the plugger to overcome gravity and wellbore resistance and descend rapidly. When the pressure at the bottom of the well exceeds the pressure at the top of the plugger, the one-way rubber ring automatically contracts, preventing reverse resistance and ensuring the plugger can smoothly pass through the variable diameter section, eccentric section, or curved section of the tubing string. The plugger continues to descend under hydraulic pressure until it reaches the set position and pressure is stopped. After pressure is stopped, the natural downhole pressure begins to exert an upward thrust on the plugger. At this time, the limiting sleeve rotates slowly under the adjustment of the damping ring, causing the limiting pin to slide from the short slide to the conversion slide position. The conversion slide creates an upward forced displacement of the slip connecting sleeve, thereby causing the slip to expand outward along the conical surface and firmly engage with the inner wall of the tubing to form an anchor. At the same time, the compression rubber sleeve set in the middle is axially compressed and radially expanded under the condition that the downhole pressure is greater than the upper pressure, so that its outer edge forms a circumferential sealing surface with the inner wall of the tubing, thus constituting a complete seal inside the tubing. At this time, overflow at the upper end of the tubing stops, indicating that the plugger has completed setting and formed a reliable seal. If the downhole pressure increases further during the sealing period, the slip and the compression rubber sleeve will become even tighter under the combined action of the conical surface and the elasticity of the rubber, so that the sealing effect increases with the pressure, achieving a passive adaptive sealing performance of "the higher the pressure, the more reliable the sealing".

[0026] The beneficial effects of this utility model are:

[0027] 1. The retractable tubing plug of this utility model uses a sawtooth-shaped rubber tower that expands under the pressure of a high-pressure nitrogen truck or water pump truck, generating a downward thrust. The rubber tower drives the guide head, causing the plug to descend against the downhole pressure. Once it reaches the designated position, the pressurization stops. Because a damping ring is provided on the slip connecting sleeve, the slip connecting sleeve drives the slip to move relative to the limiting sleeve. The limiting pin moves through a short or long slide. When entering the long slide, the slip expands outward and engages with the inner wall of the tubing, compressing the rubber cylinder to expand and seal. When entering the short slide, there is still overflow at the wellhead. At this time, pressurization continues, the limiting sleeve rotates, and the limiting pin switches to the long slide for sealing. When unsealing is required, simply restart the high-pressure nitrogen truck or water pump truck to pressurize again, and the limiting pin switches to the short slide to unseal. This invention can achieve sealing and unsealing by pressurizing and stopping the pump using a high-pressure nitrogen truck or water pump truck. Compared with the traditional method, it does not require frequent removal of the plug to replace the clip, has strong reusability, and can meet the needs of multiple cycle operations.

[0028] 2. This invention achieves reliable sealing of the tubing channel. The dual-stage compression sleeve automatically expands under differential pressure, capable of withstanding setting pressures up to 35 MPa, ensuring stable and reliable sealing performance. It can operate stably in both high-pressure and low-pressure wells and exhibits good adaptability to wellbore errors and tubing string deviations.

[0029] 3. After being unsealed, this utility model can float out of the water injection well, gas well or oil well under the action of downhole pressure without the need for tools for retrieval. It is easy to operate and meets the requirements of downhole pressurized operation.

[0030] 4. This plugging device solves a major problem that has long plagued oil pipe blockage during pressurized operations: when the oil pipe becomes blocked, and downhole tools get stuck, the oil pipe cannot be retrieved, preventing the well from resuming production and necessitating a major workover. It can significantly improve the efficiency of oil and gas field operations and substantially reduce well workover costs. Attached Figure Description

[0031] Figure 1 This is a half-sectional schematic diagram of the switchable retractable oil pipe plug of the utility model;

[0032] Figure 2 This is an enlarged connection diagram of the guide head, glue tower, glue tower shaft, inclined push block, central shaft, and expansion cup described in the utility model.

[0033] Figure 3 This is an enlarged connection diagram of the central shaft, expansion cup, sealing ring, compression rubber cylinder, rubber cylinder seat, and clamp seat described in the utility model.

[0034] Figure 4 This is an enlarged connection diagram of the clamp seat, clamp, clamp connecting sleeve, limiting pin, connecting shaft, damping ring, and limiting sliding sleeve of the utility model, where the limiting pin is in the short slide and cannot seat the blocker.

[0035] Figure 5 The enlarged connection diagram of the seat seal blocker, including the slip seat, slip, slip connecting sleeve, limiting pin, connecting shaft, damping ring, and limiting sliding sleeve, with the limiting pin located in the long slide channel;

[0036] Figure 6 This is an enlarged schematic diagram of the connecting shaft described in the utility model;

[0037] Figure 7 This is an enlarged schematic diagram of the damping ring described in the utility model;

[0038] Figure 8 This is an enlarged schematic diagram of the limiting sleeve described in the utility model;

[0039] Figure 9 This is an enlarged cross-sectional view of the limiting pin and the slip connecting sleeve described in the utility model.

[0040] Figure 10 This is an enlarged schematic diagram of the cross-section, side view, front view, and top view (three evenly arranged in a circumferential direction) of the Kawa (a type of metal clasp) described in the utility model.

[0041] Figure 11 This is an enlarged schematic diagram of the locking seat described in the utility model;

[0042] Figure 12 This is an enlarged schematic diagram of the adhesive tower shaft described in the utility model;

[0043] Figure 13 This is an enlarged schematic diagram of the central axis described in the utility model;

[0044] Figure 14 This is an enlarged schematic diagram of the inclined pusher cylinder described in the utility model;

[0045] 1. Guide head; 2. Glue tower; 3. Glue tower shaft; 4. Inclined pusher; 5. Central shaft; 6. Expansion cup; 7. Sealing ring; 8. Compression rubber cylinder; 9. Rubber cylinder seat; 10. Slip seat; 1001. Guide groove; 1002. Sealing cone surface; 11. Slip; 1101. Hook; 1102. Sliding cone surface; 12. Slip connecting sleeve; 13. Limiting pin; 14. Connecting shaft; 15. Damping ring; 1501. Damping inner ring; 1502. Damping outer ring; 16. Limiting sliding sleeve; 1601. Long slide; 1602. Short slide; 1603. Conversion slide; 17. Locking nut. Detailed Implementation

[0046] 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 skilled in the art without creative effort are within the protection scope of the present utility model.

[0047] like Figure 1 , 3 As shown, a retractable oil pipe plug includes a lowering assembly, a seat assembly, and a switching assembly.

[0048] like Figure 1 , 2 As shown, the downward moving component includes a guide head 1 and a glue tower 2. The guide head 1 is connected to the glue tower 2. The guide head 1 is provided with a conical structure, and the glue tower 2 is provided with multiple conical glue rings.

[0049] like Figure 1 , 3As shown in Figures 12, 13, and 14, the sealing assembly includes a slanted pusher 4, an expanding cup 6, a compressive rubber sleeve 8, and a rubber sleeve seat 9. The slanted pusher 4 is sleeved on a central shaft 5, which is detachably connected to a rubber tower shaft 3. The rubber tower 2 is fixed on the rubber tower shaft 3, and the slanted pusher 4 can move on the central shaft 5. The slanted pusher 4, the expanding cup 6, and the compressive rubber sleeve 8 are sequentially sleeved on the rubber sleeve seat 9. The slanted pusher 4 has opposing tapered sections at both ends, which can push the lower tapered surface under downhole pressure, thereby causing the upper tapered section to push the expanding cup 6 to open. When the rubber sleeve seat 9 is fixed, the expanding cup 6 can push the compressive rubber sleeve 8 to expand and block the inner wall of the tubing. The expanding cup 6 has a metal sleeve, and the rubber sleeve seat 9 is made of metal. Grooves are provided inside the metal sleeve and the rubber sleeve seat 9, and the grooves are filled with sealing rings 7. After the compressed rubber sleeve 8 expands, in order to seal the downhole pressure, sealing rings 7 are installed in the expansion cups 6 on both sides of the compressed rubber sleeve 8 and in the rubber sleeve seat 9. This can prevent downhole oil, gas or water from passing through the gaps between the rubber sleeve seat 9 and the central shaft 5, and between the metal casing of the expansion cup 6 and the rubber sleeve seat 9.

[0050] like Figure 1 , 4 As shown in Figure 7, the switch assembly includes a slip seat 10, a slip 11, a slip connecting sleeve 12, a damping ring 15, and a limiting slide sleeve 16. The damping ring 15 is mounted on the slip connecting sleeve 12 and includes a damping outer ring 1502 and a damping inner ring 1501. The damping inner ring 1501 is made of metal and fits onto the slip connecting sleeve 12. The damping outer ring 1502 is embedded in a groove on the outer surface of the damping inner ring 1501 and is made of rubber. The damping outer ring 1502 of the damping ring 15 has multiple liquid flow channels. These channels allow liquid to pass through when the damping ring 15 impedes the slip connecting sleeve 12, thus pushing the compression cylinder 8. Preferably, there are multiple liquid flow channels, evenly distributed in a ring shape; for example, the damping outer ring 1502 can be splined. The inner diameter of a typical oil pipe is 62mm, and the outer edge of the damping outer ring 1502 is located on a circle with a diameter of 63mm.

[0051] like Figure 1 , 4As shown in Figures 8, 9, and 11, the slip connecting sleeve 12 is detachably connected to the rubber sleeve seat 9. The slip 11 can move on the slip seat 10 and expands or contracts inward towards the inner wall of the oil pipe during movement. The slip 11 is movably connected to the slip connecting sleeve 12. A limit pin 13 is installed on the side wall of the slip connecting sleeve 12. The slip connecting sleeve 12 is installed outside the limiting slide sleeve 16 and can move relative to it. The limiting slide sleeve 16 is provided with a recessed long slide 1601, a short slide 1602, and a conversion slide 1603 on its outside. The long slideway 1601 and short slideway 1602 are located at the lower part of the limiting sleeve 16 and are spaced apart from each other. The conversion slideway 1603 is located at the upper part of the limiting sleeve 16 and is located between the long slideway 1601 and short slideway 1602. The long slideway 1601 and short slideway 1602 are connected by an inclined side, and the center projection of the conversion slideway 1603 is located on the inclined side. The limiting pin 13 is inserted into the limiting sleeve 16. When the limiting pin 13 is at the lowermost part of the long slideway 1601, the slip 11 expands to its maximum and is stuck on the inner wall of the oil pipe. The limiting sleeve 16 has two conversion slideways 1603 and two short slideways 1602. Adjacent conversion slideways 1603 or short slideways 1602 are spaced 180 degrees apart, and there are four conversion slideways 1603. The limiting pin 13 is provided with a countersunk platform and a groove to avoid clogging in the slip connecting sleeve 12. Figure 1 , 4 As shown in Figure 6, the limiting sleeve 16 is fitted onto the connecting shaft 14, and the connecting shaft 14 is detachably connected to the slip seat 10. The lower part of the connecting shaft 14 has an external thread, and the head of the slip seat 10 has an internal thread that locks it to the connecting shaft 14. The slip connecting sleeve 12 and the rubber sleeve seat 9 are connected by threads. A locking nut 17 is connected to the rear of the connecting shaft 14, and the locking nut 17 limits the movement of the limiting sleeve 16.

[0052] like Figure 1 , 4 As shown in Figures 10 and 11, there are three slips 11 evenly distributed in a ring. The guide grooves 1001 of the slip seat 10 also have three grooves, corresponding one-to-one with the slips 11. The rubber sleeve seat 9 is provided with a sealing cone surface 1002 and a guide groove 1001. A hook 1101 is provided at the front of the slip 11. The hook 1101 is inserted into the through hole at the rear of the slip connecting sleeve 12. The slip 11 can move within the guide groove 1001 of the rubber sleeve seat 9. Multiple conical teeth are provided on the outer rear part of the slip 11. A sliding cone surface 1102 is provided on the inner rear part of the slip 11, which cooperates with the sealing cone surface 1002 of the slip seat 10.

[0053] Accordingly, the usage method of the retractable oil pipe plug is disclosed, such as... Figure 3 , 4As shown, in this utility model, the retractable tubing plug, the sawtooth-shaped rubber tower 2 expands under the pressure of a high-pressure nitrogen truck or water pump truck, generating a downward thrust. The rubber tower 2 drives the guide head 1, causing the plug to descend against the downhole pressure. After reaching the designated position, the pressure is stopped, and the pressure at the lower part of the plug is greater than the pressure at the upper part. The sawtooth-shaped rubber tower 2 contracts, and the downhole pressure pushes the plug upward, which in turn drives the limiting sleeve 16 to rise. Because the slip connecting sleeve 12 is provided with a damping ring 15, the slip connecting sleeve 12 drives the slip 11 to move relative to the limiting sleeve 16. When the limiting pin 13 slides to the long slide 1601, the slip 11 moves and expands outward on the sealing cone surface 1002 of the slip seat 10. The slip 11 anchors at the tubing connection. At this time, the slip seat 10 drives the rubber sleeve seat 9 to be fixed inside the tubing wall, expanding the cup 6. The compression sleeve 8 is pushed to expand, achieving a seat seal. Overflow can be observed to have stopped at the wellhead. If the limit pin 13 slides to the short slide 1602 after the pump is stopped, the sliding stroke of the slip 11 is too short, and the outward expansion of the rear of the slip 11 is insufficient to anchor the tubing connection. Sealing cannot be achieved at this time, and overflow can still be observed at the wellhead. The pump truck needs to be restarted to pressurize. After pressurization, the plugger overcomes the downhole pressure and drops. At this time, the damping ring 15 blocks the slip 11, causing the limit pin 13 to move to the conversion slide 1603 of the limit sleeve 16. After the pump is stopped again, since the center of the conversion slide 1603 is located in the inclined side of the long slide 1601 adjacent to the short slide 1602, the limit sleeve 16 rotates when it moves upward, causing the limit pin 13 to enter the long slide 1601 adjacent to the short slide 1602. At this time, the above-mentioned seat seal process is performed.

[0054] When unsealing is required, simply start the high-pressure nitrogen truck or water pump truck, push the compression cylinder 8, and the expansion cup 6 will contract under the action of water or air pressure. The slip 11 will move upward relative to the limiting sleeve 16 and will no longer lock the oil pipe connection. The limiting pin 13 will move relative to the limiting sleeve 16 to the position of the conversion slide 1603. Since the center of the conversion slide 1603 is located in the inclined side of the short slide 1602 adjacent to the long slide 1601, after the pump is stopped again, the limiting sleeve 16 will rotate again when it moves upward, so that the limiting pin 13 enters the short slide 1602 adjacent to the long slide 1601. At this time, the unsealing process is performed.

[0055] The working principle of this utility model:

[0056] This plug solves a major problem that has long plagued oil pipe blockage during pressurized operations: when the oil pipe becomes blocked, and downhole tools get stuck, the oil pipe cannot be retrieved, preventing the well from resuming production and necessitating major workovers. It can significantly improve oilfield operational efficiency and substantially reduce well workover costs in oil and gas fields.

[0057] There are three operating conditions when using plugs on gas wells, water injection wells, or oil wells:

[0058] 1. After the plug is successfully removed, a minor repair under pressure is carried out (the downhole tools are not stuck, so there is no need to use grinding or drilling methods for major repair). At this time, the plug is removed along with the set seal tubing.

[0059] 2. Try to make a minor repair. First, sink the tank several meters and try to remove the oil pipe to see if it can be removed smoothly. If it can be repaired, after removing the plug, sink the tank further to re-seal it.

[0060] 3. If, after the plug is sealed, it is found that the problem cannot be solved by minor repairs, but the water injection well, gas well, and oil well can still be used with minimal efficiency, then the plug should be retrieved and the water injection well, oil well, and gas well should continue to be used. When they can no longer be used in the future, a comprehensive consideration should be given to whether to abandon them or carry out a major overhaul.

[0061] Traditional blockers are similar to this invention in the first relatively smooth working condition, but in the second and third working conditions, the blocker needs to be retrieved. At this time, a specially designed retrieval tool is required for retrieval, and the core seat seal component needs to be replaced after retrieval before it can be used again.

[0062] This invention allows for unsealing of the plug simply by continuing pressure and then stopping. If pressure is stopped, the plug will float upwards and exit the injection well, gas well, or oil well under downhole pressure, meeting the requirements of the third working condition, without the need for retrieval tools. If pressure is continued after the plug is unsealed, the plug will continue to descend, reaching a deeper position before pressure is stopped for resealing, meeting the requirements of the second working condition. In contrast, plugs with traditional structures require retrieval tools to be removed and repaired before they can be used.

[0063] In summary, this utility model is a switchable tubing plug that relies on liquid pressure to achieve opening and closing control and can repeatedly perform plugging and unplugging operations downhole. It is suitable for plugging the tubing channels during pressurized operations, maintenance, and repairs in oil wells, gas wells, and water injection wells.

[0064] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that the above embodiments are only for illustrating the technical concept and characteristics of this utility model, and are intended to enable those skilled in the art to understand and implement the content of this utility model. They should not be used to limit the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be covered within the scope of protection of this utility model.

Claims

1. A retractable oil pipe plug, characterized in that: It includes a downward moving component, a seat sealing component, and a switch component. The downward moving component includes a guide head (1) and a glue tower (2). The guide head (1) is connected to the glue tower (2). The guide head (1) is provided with a conical structure, and the glue tower (2) is provided with multiple conical glue rings. The sealing assembly includes a slanted pusher (4), an expansion cup (6), a compression rubber sleeve (8), and a rubber sleeve seat (9). The slanted pusher (4) has opposing cones at both ends, which can push the lower cone surface under downhole pressure, thereby causing the upper cone to push the expansion cup (6) to open. When the rubber sleeve seat (9) is fixed, the expansion cup (6) can push the compression rubber sleeve (8) to expand and block the inner wall of the tubing. The switching assembly includes a slip seat (10), slips (11), slip connecting sleeve (12), damping ring (15), and limiting sleeve (16). The damping ring (15) is mounted on the slip connecting sleeve (12), which is detachably connected to the rubber sleeve seat (9). The slips (11) can move on the slip seat (10) and expand or contract towards the inner wall of the oil pipe when moving. The slips (11) is movably connected to the slip connecting sleeve (12). A limiting pin (13) is installed on the side wall of the slip connecting sleeve (12). The slip connecting sleeve (12) is mounted outside the limiting sleeve (16) and can move relative to it. A recess is provided on the outside of the limiting sleeve (16). The slide (1601), short slide (1602), and conversion slide (1603) are located at the lower part of the limiting slide sleeve (16) and are spaced apart from each other. The conversion slide (1603) is located at the upper part of the limiting slide sleeve (16) and is located between the long slide (1601) and the short slide (1602). The long slide (1601) and the short slide (1602) are connected by an inclined side, and the center projection of the conversion slide (1603) is located on the inclined side. The limiting pin (13) is inserted into the limiting slide sleeve (16). When the limiting pin (13) is at the lowermost part of the long slide (1601), the slip (11) expands to the maximum and is stuck on the inner wall of the oil pipe.

2. The retractable oil pipe plug according to claim 1, characterized in that: The expansion cup (6) has a metal sleeve, the rubber sleeve seat (9) is made of metal, and the metal sleeve and the rubber sleeve seat (9) are provided with grooves, and the grooves are filled with sealing rings (7).

3. The retractable oil pipe plug according to claim 1, characterized in that: The damping ring (15) includes a damping outer ring (1502) and a damping inner ring (1501). The damping inner ring (1501) is made of metal and is fitted onto the slip connecting sleeve (12). The damping outer ring (1502) is embedded in the groove on the outer surface of the damping inner ring (1501) and is made of rubber. The damping outer ring (1502) of the damping ring (15) is provided with multiple channels for liquid flow.

4. The retractable oil pipe plug according to claim 1, characterized in that: The inclined pusher (4) is sleeved on the central shaft (5), the central shaft (5) is detachably connected to the glue tower shaft (3), the glue tower (2) is fixed on the glue tower shaft (3), and the inclined pusher (4) can move on the central shaft (5); the inclined pusher (4), the expansion cup (6), and the compression glue cylinder (8) are sequentially sleeved on the glue cylinder seat (9).

5. A retractable oil pipe plug according to claim 1, characterized in that: There are three slips (11) evenly distributed in a ring, and the guide groove (1001) of the slip seat (10) also has three, corresponding one to one with the slips (11).

6. The retractable oil pipe plug according to claim 1, characterized in that: The rubber sleeve seat (9) is provided with a sealing cone surface (1002) and a guide groove (1001). The front part of the slip (11) is provided with a hook (1101). The hook (1101) is inserted into the through hole at the rear of the slip connecting sleeve (12). The slip (11) can move in the guide groove (1001) of the rubber sleeve seat (9). Multiple conical teeth are provided on the outer rear part of the slip (11). A sliding cone surface (1102) is provided on the inner rear part of the slip (11) to cooperate with the sealing cone surface (1002) of the slip seat (10).

7. The retractable oil pipe plug according to claim 1, characterized in that: The limiting sleeve (16) is sleeved on the connecting shaft (14), and the connecting shaft (14) is detachably connected to the slip seat (10); a locking nut (17) is connected to the rear of the connecting shaft (14), and the locking nut (17) limits the limiting sleeve (16); the lower part of the connecting shaft (14) is provided with an external thread, and the head of the slip seat (10) is provided with an internal thread to lock the connecting shaft (14); the slip connecting sleeve (12) and the rubber sleeve seat (9) are connected by threads.

8. A retractable oil pipe plug according to claim 1, characterized in that: The limiting pin (13) is provided with a countersunk platform and a groove to prevent it from getting stuck in the slip connecting sleeve (12).

9. A retractable oil pipe plug according to claim 1, characterized in that: The limiting slide sleeve (16) has two conversion slides (1603) and two short slides (1602). Adjacent conversion slides (1603) or short slides (1602) are spaced 180 degrees apart, and four conversion slides (1603) are provided.

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