Bridge plug for oil wells

Abstract

The application relates to the technical field of oilfield well exploitation, in particular to a bridge plug for oilfields, which comprises an outer sealing body, a central pipe is fixedly installed on the inner side of the top end of the outer sealing body, a plurality of inclined holes are formed in the top end of the central pipe, a threaded groove is arranged on the outer side of the top end of the central pipe, a plurality of installation grooves one are formed on the outer side of the top end of the outer sealing body, a sealing body is movably sleeved on the inner side of the installation grooves one, a plurality of wedge clamping teeth are fixedly installed on the inner side of the sealing body; when the bridge plug is unsealed, the electromagnetic iron is powered in the reverse direction, the magnetic pole of the electromagnetic iron is reversed, the permanent magnet one is subjected to an adsorption force, the permanent magnet one is close to each other, the displacement is used to pull and stretch the cable, the clamping head is reset to be separated from the clamping position of the clamping hole, the sealing piston one and the sealing piston four are limited to be in contact, the structure is reset under the action of pressure and elasticity, the structure is unsealed, the whole is unsealed and set, gunpowder is not needed for the whole unsealing and setting, the environmental protection performance is good, and the bridge plug is convenient to use.

Description

Technical Field

[0001] This invention relates to the field of oilfield well development technology, specifically to a bridge plug for oilfield use. Background Technology

[0002] Bridge plugs for oilfields are core tools for downhole sealing operations in oil and gas wells. They are mainly delivered to the target well depth through the coordinated action of anchoring, sealing, setting, and locking mechanisms, triggering the setting process. The inclined force amplification effect of the cone-slip mechanism ensures that the slips anchor the inner wall of the casing and the sealing sleeve tightly adheres to the annulus, effectively isolating oil and gas flows in different well sections. This controls inter-layer interference and ensures the safe and efficient conduct of operations such as stratified oil testing, fracturing, well workover, or well abandonment. According to the unsealing method, they can be divided into permanent, retrievable, and soluble types, suitable for different well conditions such as vertical wells, horizontal wells, and high-temperature and high-pressure wells. Currently, they are developing towards intelligent, large-diameter, and green biodegradable technologies, gradually replacing traditional cement plug processes and significantly reducing operating costs and reservoir contamination risks.

[0003] In the process of oilfield and gas well development, it is necessary to isolate different sections of the wellbore to achieve effective control of oil, gas, and water layers. Therefore, oilfield bridge plugs are required. Oilfield bridge plugs are the core tool for downhole sealing operations in oil and gas wells. After being delivered to the target well depth, they are used for sealing. However, during the use of bridge plugs, the integrated slips may fail to lock due to corrosion or burrs on the inner wall of the casing. Furthermore, for retrievable bridge plugs, when using retrieval tools, the unsealing mechanism may become stuck during retrieval, making it difficult to unseal the bridge plug. Forcibly retrieving the bridge plug may cause it to disintegrate, with residual parts falling into the well. If setting is done with explosives, improper handling may lead to contamination. Moreover, if the sealing structure is damaged due to burrs on the inner wall of the pipe and leakage occurs, it cannot be detected immediately. The quality of setting cannot be verified in real time, and it is difficult to locate the fault after failure. This results in low retrieval and deployment efficiency and difficulty in controlling the dynamics of setting. Based on this, an oilfield bridge plug is proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a bridge plug for oil fields to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an oilfield bridge plug, comprising an outer sealing body, a central tube fixedly installed on the inner side of the top end of the outer sealing body, a plurality of oblique holes formed at the top end of the central tube, a threaded groove formed on the outer side of the top end of the central tube, a plurality of mounting grooves formed on the outer side of the top end of the outer sealing body, a sealing body movably sleeved on the inner side of the mounting grooves, a plurality of wedge teeth fixedly installed on the inner side of the sealing body, and a toothed sleeve slidably sleeved on the opposite side of the top ends of the outer sealing body and the central tube, wherein a self-healing agent microcapsule is fixedly embedded inside the sealing body, and the self-healing agent... A micro-starting electrode is movably mounted on one side of the microcapsule. A binding groove is formed on the outer side of the bottom end of the outer seal. Several mounting grooves are formed on the outer side of the bottom end of the outer seal. Several segmented slips are slidably mounted inside the mounting grooves. A segmented inclined ring is fixedly mounted on the opposite side of the segmented slips. A conical inclined push ring is slidably mounted on the opposite side of the segmented inclined ring. A counterweight column is fixedly sleeved on the opposite side of the conical inclined push ring. A sealing piston is fixedly mounted on the top of the counterweight column. A bottom cone head is fixedly mounted on the bottom end of the outer seal. A central tube is fixedly mounted inside. An electromagnet has a permanent magnet at both its top and bottom. A sealing piston is movably fitted to the top of the upper permanent magnet, and a sealing piston is movably fitted to the bottom of the lower permanent magnet. Several mounting grooves are formed inside the opposing sides of both the sealing pistons. Limiting rings are fixedly fitted inside the opposing ends of the mounting grooves. Clamping heads are slidably installed inside the opposing ends of the mounting grooves. Clamping heads have movably inserted holes at their opposing ends. Return springs are fixedly installed at the opposing ends of the clamping heads, and a retractable cable is fitted inside the return springs. A second sealing piston is movably sleeved on the inner side of the top end of the central tube. A small motor is fixedly installed on the top of the second sealing piston. The output shaft of the small motor is driven by a turbofan blade. A fixed partition is movably sleeved on the outer side of the output shaft of the small motor through a sealing structure. A limit ring is fixedly installed on the top of the second sealing piston. Hydraulic chambers two are provided on the opposite sides of the fourth and third sealing pistons. Hydraulic chambers one are provided on the opposite sides of the first and second sealing pistons. Several through holes are opened inside the top end of the central tube. A micro sensor group is installed on the top of the second sealing piston.

[0006] Preferably, the top of the central tube is provided with a plurality of slots, which are evenly distributed in a circle on the top of the central tube. The oblique holes are evenly distributed in a circle on the top of the central tube and are distributed at an upward angle. The top of the outer sealing body is an oblique surface.

[0007] Preferably, the wedge teeth are evenly distributed circumferentially on the inner side of the sealing body, the wedge teeth move through the outer sealing body and extend to the outer side of the central tube, the outer side of the tooth sleeve is provided with a beveled groove adapted to the wedge teeth, and piston rings are fixedly installed at the top and bottom of the tooth sleeve, the piston rings are movably sleeved on the opposite sides of the outer sealing body and the central tube.

[0008] Preferably, the micro-starting electrode is fixedly installed inside the wedge tooth via a groove, the mounting groove and the sealing body are linearly and evenly distributed on the outer side of the top of the outer sealing body, and a number of sealing strips are fixedly sleeved on the outer side of the outer sealing body, the sealing strips being linearly and evenly distributed on the outer side of the outer sealing body.

[0009] Preferably, the second mounting groove is evenly distributed circumferentially on the outer side of the outer seal, the segmented slips are evenly distributed linearly inside the second mounting groove, the segmented slips move through the second mounting groove and extend into the interior of the outer seal, the conical inclined push ring is evenly distributed linearly on the outer side of the counterweight column, and a silicone base pad is fixedly installed at the bottom of the counterweight column.

[0010] Preferably, the first permanent magnet is movably sleeved inside the central tube, and the first and fourth sealing pistons are both movably and sealingly sleeved inside the central tube, with the first permanent magnet and the electromagnet arranged with their magnetic poles facing each other.

[0011] Preferably, the locking holes are opened inside the outer seal and the central tube, and the locking holes are evenly distributed circumferentially inside the outer seal and the central tube. The outer side of the locking head is rounded. The return spring is sleeved inside the mounting groove three. The opposite ends of the retractable cable are fixedly installed on the opposite ends of the locking head. The retractable cable is movably sleeved through the inner side of the limiting seat ring. The opposite ends of the retractable cable are fixedly connected to the opposite side of the first permanent magnet. The opposite ends of the retractable cable are connected to the center of the first permanent magnet.

[0012] Preferably, the through holes are evenly distributed circumferentially inside the central tube, and the two ends of the through holes are respectively connected to the inside of the first hydraulic chamber and the bottom of the toothed sleeve. The fixed partition is fixedly sleeved inside the central tube, and hydraulic oil is provided on the inner side of both the second hydraulic chamber and the first hydraulic chamber.

[0013] Preferably, the outer side of the outer seal is provided with a graphene coating, and the opposite sides of the conical inclined push ring and the segmented inclined ring and the opposite sides of the toothed sleeve and the wedge tooth are all sprayed with a molybdenum disulfide wear-resistant coating. The inclination angle between the opposite sides of the conical inclined push ring and the segmented inclined ring and the opposite sides of the toothed sleeve and the wedge tooth is in the range of 12° to 30°.

[0014] Preferably, a control component is fixedly mounted on the top of the second sealed piston, and the micro-sensor group includes temperature, pressure, vibration, and displacement sensors.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. When the equipment is in use, the operator places the outer seal body in the downhole position through the slot and threaded groove, and then starts the setting seal. The electromagnet generates electromagnetic force and generates electromagnetic repulsion force with the permanent magnets on both sides, causing the two permanent magnets to move in opposite directions. The upper permanent magnet pushes the sealing piston upward and generates pressure on the hydraulic chamber. The hydraulic pressure enters the area where the toothed sleeve is located through the through hole. At this time, the toothed sleeve is lifted up, and through the inclined surface of the wedge tooth, the wedge tooth and the seal body expand outward, thereby making it fit against the pipe wall. Contact causes the sealing body to be compressed and deformed within the mounting groove and pipe wall, sealing the gap. The permanent magnet at the bottom pushes the sealing piston four downward, which in turn causes the sealing piston three and the counterweight column to move downward through the hydraulic chamber two. This, in turn, pushes the segmented inclined ring through the inclined surface of the conical push ring, causing the segmented slips to expand and lock into the inner side of the pipe wall, forming a fixed position. During the displacement process, the chuck moves under the elastic force of the return spring and locks into the inside of the chuck hole, thereby fixing the sealing piston one and sealing piston four in position and preventing them from returning to their original position. The overall setting is convenient and has a good effect. 2. During unsealing, the electromagnet is switched to a different power source, causing the electromagnet poles to reverse and attract the permanent magnet one. This causes the permanent magnets one to move closer together, and the displacement pulls and retracts the rope, thereby causing the chuck to reset and disengage from the chuck hole. This, in turn, causes the sealing piston one and sealing piston four to make limiting contact. The structure resets under pressure and elasticity, thus unsealing the structure. The overall unsealing and setting does not require gunpowder, is environmentally friendly, and is convenient to use.

[0016] 3. If the seal body breaks and leaks during setting, the leaking fluid will be introduced into the location of the inclined hole through the gap between the outer seal body and the pipe wall. Part of it will be diverted through the inclined hole and directed to the turbine blade, causing the turbine blade to rotate and the small motor to generate a weak and continuous current. The fluid leakage can be detected by monitoring the change in this current. Under controllable conditions, the self-healing agent microcapsule outer shell can be activated by the micro-starting electrode, causing the internal self-healing agent to leak out and seal the broken gaps in the seal body. This achieves the effect of knowing the setting situation and controlling some situations, which can help operators select partial control and delay the selection of solutions, and indirectly ensure the quality of setting. Attached Figure Description

[0017] Figure 1 This is a front-view stereoscopic structural diagram of the present invention.

[0018] Figure 2 This is a schematic diagram of the three-dimensional appearance structure of the present invention from a rear-view or upward-view perspective.

[0019] Figure 3 This is a front sectional view of the internal structure of the present invention.

[0020] Figure 4This is a schematic diagram of the internal structure of the present invention, viewed from the right side.

[0021] Figure 5 This is a top view of the external structure of the present invention.

[0022] Figure 6 For the present invention Figure 3 Enlarged structural diagram at point A in the middle.

[0023] Figure 7 For the present invention Figure 3 Enlarged structural diagram at point B.

[0024] Figure 8 For the present invention Figure 3 Enlarged structural diagram at point C.

[0025] Figure 9 For the present invention Figure 3 Enlarged structural diagram at point D.

[0026] In the diagram: 1. Outer sealing body; 2. Central tube; 3. Slot; 4. Inclined hole; 5. Threaded groove; 6. Sealing body; 7. Mounting groove one; 8. Mounting groove two; 9. Segmented slip; 10. Bottom cone head; 11. Binding groove; 12. Sealing strip; 13. Sealing piston one; 14. Permanent magnet one; 15. Electromagnet; 16. Hydraulic chamber one; 17. Sealing piston two; 18. Fixed partition; 19. Turbine fan blade; 20. Slipper sleeve; 21. Wedge slip; 22. Through hole; 23. Hydraulic Chamber II; 24. Sealed Piston III; 25. Counterweight Column; 26. Silicone Base Pad; 27. Conical Inclined Push Ring; 28. Segmented Inclined Ring; 29. ​​Small Motor; 30. Control Components; 31. Sealed Piston IV; 32. Limiting Ring; 33. Miniature Sensor Group; 34. Self-Healing Agent Microcapsule; 35. Micro-Starting Electrode; 36. Card Hole; 37. Card Head; 38. Mounting Slot III; 39. Return Spring; 40. Limiting Seat Ring; 41. Retractable Rope. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Please see Figures 1-9This invention provides a technical solution: an oilfield bridge plug, comprising an outer sealing body 1, a central tube 2 fixedly installed on the inner side of the top end of the outer sealing body 1, a plurality of oblique holes 4 opened at the top end of the central tube 2, a threaded groove 5 provided on the outer side of the top end of the central tube 2, a plurality of mounting grooves 7 opened on the outer side of the top end of the outer sealing body 1, a sealing body 6 movably sleeved on the inner side of the mounting grooves 7, a plurality of wedge teeth 21 fixedly installed on the inner side of the sealing body 6, a tooth sleeve 20 slidably sleeved on the opposite side of the top ends of the outer sealing body 1 and the central tube 2, a self-healing agent microcapsule 34 fixedly embedded inside the sealing body 6, and a micro-starter movably installed on one side of the self-healing agent microcapsule 34. Electrode 35, a binding groove 11 is provided on the outer side of the bottom end of the outer sealing body 1, and several mounting grooves 8 are provided on the outer side of the bottom end of the outer sealing body 1. Several segmented slips 9 are slidably installed inside the mounting grooves 8. A segmented inclined ring 28 is fixedly installed on the opposite side of the segmented slips 9. A conical inclined push ring 27 is slidably installed on the opposite side of the segmented inclined ring 28. A counterweight column 25 is fixedly sleeved on the opposite side of the conical inclined push ring 27. A sealing piston 3 24 is fixedly installed on the top of the counterweight column 25. A bottom cone head 10 is fixedly installed at the bottom end of the outer sealing body 1. An electromagnet 15 is fixedly installed inside the central tube 2. The top and bottom of the electromagnet 15 are provided with A permanent magnet 14 is placed therein. A sealing piston 13 is movably attached to the top of the upper permanent magnet 14, and a sealing piston 41 is movably attached to the bottom of the lower permanent magnet 14. Several mounting grooves 38 are formed inside the opposing sides of the sealing pistons 13 and 41. Limiting rings 40 are fixedly sleeved inside the opposing ends of the mounting grooves 38. Clamping heads 37 are slidably installed inside the opposing ends of the mounting grooves 38. Clamping holes 36 are movably inserted into the opposing ends of the clamping heads 37. Return springs 39 are fixedly installed at the opposing ends of the clamping heads 37. A retractable rope 41 is sleeved inside the return springs 39. The top of the central tube 2... A sealing piston 217 is movably sleeved on the inner side of the central tube 2. A small motor 29 is fixedly installed on the top of the sealing piston 217. The output shaft of the small motor 29 is driven by a turbine blade 19. A fixed partition 18 is movably sleeved on the outer side of the output shaft of the small motor 29 through a sealing structure. A limit ring 32 is fixedly installed on the top of the sealing piston 217. A hydraulic chamber 23 is provided on the opposite side of the sealing piston 4 31 and the sealing piston 3 24. A hydraulic chamber 16 is provided on the opposite side of the sealing piston 1 13 and the sealing piston 217. Several through holes 22 are opened inside the top of the central tube 2. A micro sensor group 33 is installed on the top of the sealing piston 217.

[0029] The working principle of the above technical solution is as follows: During use, the operator places the outer sealing body 1 in the downhole position through the slot 3 and threaded groove 5, and then starts the setting seal. First, the electromagnet 15 is energized, generating electromagnetic force and electromagnetic repulsion between it and the permanent magnets 14 on both sides, causing the two permanent magnets 14 to move in opposite directions. The upper permanent magnet 14 pushes the sealing piston 13 upward and generates pressure on the hydraulic chamber 16. Hydraulic fluid enters the area where the toothed sleeve 20 is located through the through hole 22, lifting the toothed sleeve 20. Through the inclined surface of the wedge tooth 21, the wedge tooth 21 and the sealing body 6 expand outward, thus making contact with the pipe wall. This causes the sealing body 6 to be compressed and deformed in the installation groove 7 and the pipe wall, sealing the gap. The hydraulic oil causes the sealing piston 17 to move upward, pushing the small motor 29 and the turbine blade 19 upward, so that the turbine blade 19 is in the inclined output direction of the inclined hole 4. The lower permanent magnet 14 pushes the sealing piston 31 downward, and through the hydraulic chamber 23, the sealing body is sealed. Piston 3 24 and counterweight column 25 move downwards, which in turn pushes the segmented inclined surface ring 28 to move through the inclined surface of the conical inclined push ring 27. This causes the segmented slip 9 to expand and lock into the inner side of the pipe wall, forming a fixed position. During the displacement of sealing piston 1 13 and sealing piston 4 31, the clamping head 37 moves under the elastic force of the return spring 39 and locks into the inside of the clamping hole 36, thereby fixing the position of sealing piston 1 13 and sealing piston 4 31 and preventing them from returning to their original position. The overall setting is convenient and the use effect is good. When the electromagnet 15 is switched to a different power source, the magnetic poles of the electromagnet 15 reverse and attract the permanent magnet 14, causing the permanent magnets 14 to move closer together. The displacement pulls and retracts the cable 41, thereby causing the clamp 37 to reset and disengage from the clamping position of the clamping hole 36. This allows the sealing piston 13 and sealing piston 41 to make limiting contact. The structure resets under pressure and elasticity, thus unsealing the structure. The overall unsealing and setting does not require gunpowder, is environmentally friendly, and is easy to use. If the sealing body 6 is damaged and leaks during setting, the leaked fluid will be introduced into the location of the inclined hole 4 through the gap between the outer sealing body 1 and the pipe wall. Part of it will be diverted through the inclined hole 4 and directed to the position of the turbine blade 19, causing the turbine blade 19 to rotate and the small motor 29 to generate a weak and continuous current. The change of this current can be monitored to know the fluid leakage. Under controllable conditions, the self-healing agent microcapsule 34 is activated by the micro-starting electrode 35, causing the internal self-healing agent to leak out, thereby sealing the broken gap of the sealing body 6. This achieves the effect of knowing the setting situation and controlling some situations, which can help the operator to select partial control and delay the selection of the solution, and indirectly ensure the quality of setting.

[0030] In another implementation scheme, such as Figures 1-9 As shown, the top of the central tube 2 is provided with several slots 3, which are evenly distributed in a circle on the top of the central tube 2. The oblique holes 4 are evenly distributed in a circle on the top of the central tube 2, and the oblique holes 4 are distributed at an angle upward. The top of the outer sealing body 1 is an oblique surface.

[0031] The slot 3 facilitates force-bearing clamping and can be combined with other workpieces. The oblique hole 4 serves to facilitate the insertion and supply of the feed hole, as well as to guide the flow and facilitate the flow of fluid through the diversion channel, in conjunction with the fluid of the turbine blade 19.

[0032] In another implementation scheme, such as Figures 1-9 As shown, the wedge teeth 21 are evenly distributed in a circle on the inner side of the sealing body 6. The wedge teeth 21 can move through the outer sealing body 1 and extend to the outer side of the central tube 2. The outer side of the tooth sleeve 20 is provided with a beveled groove that matches the wedge teeth 21. Piston rings are fixedly installed at the top and bottom of the tooth sleeve 20. The piston rings can move and fit on the opposite sides of the outer sealing body 1 and the central tube 2.

[0033] The wedge teeth 21 are circumferentially distributed on the inner side of the sealing body 6. When compressed, they cause the sealing body 6 to deform and fit against the gap between the mounting groove 7 and the wedge teeth 21, so that the sealing body 6 deforms and compresses against the pipe wall and the opposite side of the mounting groove 7, resulting in a good overall sealing effect. It is convenient for the tooth sleeve 20 to push the wedge teeth 21, thereby causing the sealing body 6 to move. The piston ring seals and isolates the tooth sleeve 20 and the wedge teeth 21. It is driven by fluid and prevents fluid from entering the opposite side of the outer sealing body 1 and the central tube 2 through the broken gap, which is convenient for use.

[0034] In another implementation scheme, such as Figures 1-9 As shown, the micro-starting electrode 35 is fixedly installed inside the wedge tooth 21 through a groove. The mounting groove 7 and the sealing body 6 are linearly and evenly distributed on the outer side of the top of the outer sealing body 1. Several sealing strips 12 are fixedly sleeved on the outer side of the outer sealing body 1. The sealing strips 12 are linearly and evenly distributed on the outer side of the outer sealing body 1.

[0035] The sealing body 6 contains a microcapsule-type self-healing agent with a polymer repair fluid. When the sealing body 6 is scratched or corroded, resulting in microcracks, the capsules rupture to release the repair fluid, which quickly fills the cracks and cures, restoring the sealing performance. The repair agent consists of a matrix material, microcapsule self-healing agent, and functional additives, such as hydrogenated nitrile butadiene rubber (HNBR, acrylonitrile content 36%), microcapsule self-healing agent (wall material: urea-formaldehyde resin; core material: epoxy resin E-51 + polyamide curing agent 650, core-to-wall ratio = 3:1), silica (reinforcing agent), graphene (sheet form, anti-corrosion additive), antioxidant RD, and plasticizer (phthalic acid). Dioctyl diformate (DOP), vulcanizing agent (dicumyl peroxide, DCP), (based on 100 parts of hydrogenated nitrile rubber and adjusted according to actual conditions, such as 25-30 parts of silica, etc.) Overall performance indicators: after vulcanization, the rubber sleeve hardness Shore A 75-80, tensile strength ≥18MPa, sealing rate >98% after immersion in corrosive medium for 72 hours; self-repair efficiency after scratches >85%. Small-scale vulcanization tests were conducted for different specific well temperatures, pressures, and corrosive medium concentrations to test mechanical properties and self-repair efficiency. Combined with the structural dimensions of the bridge plug rubber sleeve, the fluidity of the rubber compound and the vulcanization process parameters, as well as the formula ratio, were adjusted. Under specific conditions, the outer shell of the damaged self-repair agent microcapsule 34 can be activated by the micro-starting electrode 35, causing the self-repairing fluid to flow out, thereby enabling the structure to self-repair under specific conditions. The micro-starting electrode 35 can be composed of a trigger electrode or micro-powder, the purpose of which is to actively trigger the flow of the self-repairing fluid from the self-repair agent microcapsule 34.

[0036] In another implementation scheme, such as Figures 1-9 As shown, the mounting groove 28 is evenly distributed on the outer side of the outer seal 1 in a circular pattern, the segmented slips 9 are evenly distributed linearly inside the mounting groove 28, the segmented slips 9 move through the mounting groove 28 and extend into the interior of the outer seal 1, the conical inclined push ring 27 is evenly distributed linearly on the outer side of the counterweight column 25, and a silicone base pad 26 is fixedly installed at the bottom of the counterweight column 25.

[0037] The counterweight column 25 moves downward, pushing the segmented inclined surface ring 28 through the conical inclined push ring 27. Through the self-weight of the counterweight column 25 and the liquid conduction of the hydraulic chamber 23, the segmented slips 9 are pushed out. This allows for the use of split symmetrical slips, which are evenly distributed around the cone. When pushing the cone, it is necessary to ensure that each slip opens synchronously to avoid unilateral force causing bridge plug deflection. In addition, a flexible slip structure can be adopted according to actual conditions, replacing the split slips with elastic alloy sheet slips. The inclined surface is more evenly stressed, the force amplification efficiency is improved, and it is suitable for deformable casing wells. The silicone bottom pad 26 avoids strong impacts and vibrations, ensuring the stable operation of the structure.

[0038] In another implementation scheme, such as Figures 1-9As shown, permanent magnet 14 is movably sleeved inside the central tube 2, and sealing piston 13 and sealing piston 4 31 are both movably and sealingly sleeved inside the central tube 2. Permanent magnet 14 and electromagnet 15 are arranged with their magnetic poles facing each other.

[0039] The coil winding of electromagnet 15 uses copper flat wire covered with polyimide (PI) insulation, with a temperature resistance rating of ≥180℃ to adapt to high-temperature working conditions in deep wells. The wire diameter is calculated according to the thrust requirements; the larger the wire diameter, the higher the current carrying capacity and the stronger the thrust. In the winding process, the coil needs to be tightly wound on the magnetic pole core and filled with high-temperature resistant epoxy resin for curing to prevent the coil from loosening due to downhole vibration. At the same time, a heat dissipation gap is reserved to avoid the heat generated by the instantaneous large current burning the insulation layer. Permanent magnet 14 and electromagnet 15 achieve the effect of propulsion and recovery by reversing and aligning the magnetic poles. This facilitates setting and unsealing, and makes it easy to move the sealing piston 13 and sealing piston 4 31, facilitating coordinated operation.

[0040] In another implementation scheme, such as Figures 1-9 As shown, the locking holes 36 are opened inside the outer sealing body 1 and the central tube 2. The locking holes 36 are evenly distributed in a circle inside the outer sealing body 1 and the central tube 2. The outer side of the locking head 37 is rounded. The return spring 39 is sleeved inside the mounting groove 38. The opposite ends of the retraction cable 41 are fixedly installed on the opposite ends of the locking head 37. The retraction cable 41 is movably sleeved and passes through the inner side of the limiting seat ring 40. The opposite ends of the retraction cable 41 are fixedly connected to the opposite side of the permanent magnet 14. The opposite ends of the retraction cable 41 are connected to the center of the permanent magnet 14.

[0041] During the displacement of sealing piston 13 and sealing piston 4 31, the locking head 37 moves under the elastic force of the return spring 39 and locks into the inside of the locking hole 36, thereby fixing the sealing piston 13 and sealing piston 4 31 in position and preventing them from returning to their original position. The overall sealing is convenient and has a good effect. When unsealing, the electromagnet 15 is induced to reverse the power supply, causing the magnetic pole of the electromagnet 15 to reverse and form an attraction force on the permanent magnet 14, causing the permanent magnets 14 to move closer to each other. The displacement pulls the retracted rope 41, thereby causing the locking head 37 to reset and disengage from the locking position of the locking hole 36, thus making the sealing piston 13 and sealing piston 4 31 in limiting contact. The structure resets under the action of pressure and elasticity, thereby unsealing the structure.

[0042] In another implementation scheme, such as Figures 1-9 As shown, through holes 22 are evenly distributed in a circle inside the central tube 2. The two ends of through holes 22 are connected to the inside of hydraulic chamber 16 and the bottom of the toothed sleeve 20, respectively. The fixed partition 18 is fixedly sleeved inside the central tube 2. Hydraulic oil is provided on the inner side of both hydraulic chamber 23 and hydraulic chamber 16.

[0043] Through hole 22 guides the oil inside hydraulic chamber 16 into the bottom of toothed sleeve 20, thereby achieving displacement and pushing. Fixed partition 18 blocks the limiting ring 32, protecting the small motor 29, micro sensor group 33, and control component 30, and providing initial isolation from the external environment. When dealing with areas with high pressure, the number of fixed partitions 18 can be increased, and the small motor 29 can be configured with high temperature and high pressure resistance, placed in the middle of the multi-layer fixed partitions 18, and the small motor 29 can be deprived of its pushing displacement function from the sealing piston 17, so that the turbine blade 19 is placed in the middle of the inclined hole 4. This solution is designed to deal with conventional oil and gas well parameters. The shaft of the small motor 29 is movably connected to the fixed partition 18 through a flexible rotating sealing ring component, which facilitates rotation and displacement, and allows for easy adjustment of parameters and functions according to actual needs, increasing convenience.

[0044] In another implementation scheme, such as Figures 1-9 As shown, the outer side of the outer cover 1 is coated with graphene. The opposite sides of the conical inclined push ring 27 and the segmented inclined ring 28, as well as the opposite sides of the toothed sleeve 20 and the wedge toothed 21, are all coated with a molybdenum disulfide wear-resistant coating. The inclination angle between the opposite sides of the conical inclined push ring 27 and the segmented inclined ring 28 and the opposite sides of the toothed sleeve 20 and the wedge toothed 21 is in the range of 12° to 30°.

[0045] Continuing the traditional 12°-30° inclination angle, taking into account both force amplification and unsealing feasibility, the electromagnetic thrust amplification factor is determined by the inclination angle. The cone's inclined surface is sprayed with a molybdenum disulfide wear-resistant coating to reduce the friction coefficient with the slips, reduce force transmission loss, and improve anchoring efficiency. Through the wear-resistant coating, the parts of the outer sealing body 1 and the central pipe 2 that come into contact with the oil and gas well environment are made more wear-resistant, which facilitates subsequent operations and increases the effectiveness of use.

[0046] In another implementation scheme, such as Figures 1-9 As shown, a control component 30 is fixedly installed on the top of the sealed piston 2 17, and the miniature sensor group 33 includes temperature, pressure, vibration and displacement sensors.

[0047] The built-in micro-sensor group 33 includes temperature, pressure, vibration, and displacement sensors. It adopts acoustic wireless transmission technology, eliminating the need for cables and avoiding the risk of cable breakage in deep wells. It transmits data to the surface in real time: ① the opening status of the slips during setting, ② the pressure stability of the sealing cavity after setting, and ③ the later dissolution / corrosion status, realizing visualization of the bridge plug operation. The surface can accurately determine whether the setting is successful, avoiding interlayer flow caused by "false setting". In case of failure, it can locate the problematic part and guide subsequent remedial measures. It adopts electromagnetic or acoustic remote control technology, and the surface emits electromagnetic or acoustic signals of a specific frequency to remotely trigger the setting and unsetting mechanism of the bridge plug. It does not require cables or tubing pressurization, making it suitable for complex well conditions such as small wellbores and deep wells. Combined with the developed predictive digital model, the system accuracy is improved. The trigger power supply component of control component 30 uses a lithium thionyl chloride battery, which has high energy density, a temperature resistance range of -40℃ to 180℃, and a storage life of ≥10 years, making it suitable for long-term downhole storage. The power is matched to the battery's requirements, which necessitate an instantaneous output current of ≥50A and a continuous power supply time of ≥100ms to meet the instantaneous thrust requirements of electromagnetic repulsion. The battery capacity is designed based on the number of triggers, with 2-3 redundant triggers reserved. Furthermore, the control circuit of control component 30 uses a high-temperature resistant ASIC chip, integrating current protection, over-temperature protection, and wireless communication functions. The circuit is encapsulated in a 316L stainless steel sealed chamber with a protection rating of ≥IP68, preventing downhole oil, water, and corrosion. Depending on the operating environment, the electromagnetic components and control circuit can be individually encapsulated in a stainless steel pressure-resistant chamber with a wall thickness of ≥10mm and metal sealing gaskets, capable of withstanding downhole pressures of ≥100MPa to prevent high-pressure fluid intrusion. The magnetic pole core and the inner wall of the sealed chamber are coated with a graphene anti-corrosion coating, making them corrosion-resistant. The coil insulation layer is made of perfluoroether rubber, which is oil-resistant and acid and alkali-resistant, preventing insulation failure caused by corrosive media. A high-temperature resistant silicone buffer layer is filled between the electromagnetic components and the sealed chamber to absorb vibration and impact during transportation or positioning. It has an impact resistance of ≥5000g, preventing coil loosening and magnetic pole displacement, and has anti-vibration and impact functions.

[0048] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A bridge plug for oilfield use, comprising an outer sealing body (1), characterized in that: A central tube (2) is fixedly installed on the inner side of the top end of the outer sealing body (1). Several oblique holes (4) are opened at the top end of the central tube (2). A threaded groove (5) is provided on the outer side of the top end of the central tube (2). Several mounting grooves (7) are opened on the outer side of the top end of the outer sealing body (1). A sealing body (6) is movably sleeved on the inner side of the mounting groove (7). Several wedge teeth (21) are fixedly installed on the inner side of the sealing body (6). A tooth sleeve (20) is slidably sleeved on the opposite side of the top ends of the outer sealing body (1) and the central tube (2). A self-healing agent microcapsule (34) is fixedly embedded inside the sealing body (6). A micro-starting electrode (35) is movably installed on one side of the self-healing agent microcapsule (34). The outer sealing body (1) A binding groove (11) is provided on the outer side of the bottom end. Several mounting grooves (8) are provided on the outer side of the bottom end of the outer sealing body (1). Several segmented slips (9) are slidably installed inside the mounting grooves (8). A segmented inclined ring (28) is fixedly installed on the opposite side of the segmented slips (9). A conical inclined push ring (27) is slidably installed on the opposite side of the segmented inclined ring (28). A counterweight column (25) is fixedly sleeved on the opposite side of the conical inclined push ring (27). A sealing piston (24) is fixedly installed on the top of the counterweight column (25). A bottom cone head (10) is fixedly installed at the bottom end of the outer sealing body (1). An electromagnet (15) is fixedly installed inside the central tube (2). The top of the electromagnet (15) and A permanent magnet (14) is provided at the bottom of each of the four permanent magnets. A sealing piston (13) is movably attached to the top of the upper permanent magnet (14), and a sealing piston (31) is movably attached to the bottom of the lower permanent magnet (14). Several mounting grooves (38) are provided inside the opposite sides of the sealing pistons (13) and (31). A limiting seat ring (40) is fixedly sleeved inside the opposite ends of the mounting grooves (38). A clamp (37) is slidably installed inside the opposite ends of the mounting grooves (38). A clamp hole (36) is movably inserted into the opposite ends of the clamps (37). A return spring (39) is fixedly installed at the opposite ends of the clamps (37). A retractable cable is sleeved inside the return spring (39). (41) A sealing piston two (17) is movably sleeved on the inner side of the top end of the central tube (2). A small motor (29) is fixedly installed on the top of the sealing piston two (17). The output shaft of the small motor (29) is connected to a turbine blade (19). A fixed partition (18) is movably sleeved on the outer side of the output shaft of the small motor (29) through a sealing structure. A limit ring (32) is fixedly installed on the top of the sealing piston two (17). A hydraulic chamber two (23) is provided on the opposite side of the sealing piston four (31) and the sealing piston three (24). A hydraulic chamber one (16) is provided on the opposite side of the sealing piston one (13) and the sealing piston two (17). Several through holes (22) are opened inside the top end of the central tube (2).A micro-sensor assembly (33) is mounted on the top of the second sealed piston (17); When the sealing is started, the electromagnet (15) is energized first, generating electromagnetic force and electromagnetic repulsion between it and the two permanent magnets (14) on both sides, causing the two permanent magnets (14) to move in opposite directions. The upper permanent magnet (14) pushes the sealing piston (13) upward and generates pressure on the hydraulic chamber (16). The hydraulic fluid enters the area where the toothed sleeve (20) is located through the through hole (22), which lifts the toothed sleeve (20) and causes the wedge tooth (21) and the sealing body (6) to expand outward through the inclined surface of the wedge tooth (21), so that they come into contact with the pipe wall. This causes the sealing body (6) to be squeezed and deformed in the mounting groove (7) and the pipe wall. Inside, the gap is sealed, and the hydraulic oil causes the sealing piston two (17) to move upward, and pushes the small motor (29) and the turbine blade (19) upward, so that the turbine blade (19) is in the oblique output direction of the inclined hole (4). The permanent magnet one (14) at the bottom pushes the sealing piston four (31) downward, and through the hydraulic chamber two (23), it causes the sealing piston three (24) and the counterweight column (25) to move downward. Then, through the inclined surface of the conical inclined push ring (27), it pushes the segmented inclined surface ring (28) to move, so that the segmented slip (9) expands and is stuck on the inner side of the pipe wall, forming a fixed position. During the displacement process, the sealing piston one (13) and the sealing piston four (31) are stuck. The head (37) moves under the elastic force of the return spring (39) and is inserted into the inside of the card hole (36), thereby fixing the position of the sealing piston one (13) and the sealing piston four (31) to prevent them from returning to their original positions. When unsealing, the electromagnet (15) is induced to reverse its power supply, causing the magnetic poles of the electromagnet (15) to reverse and form an attraction force on the permanent magnet one (14), causing the permanent magnet one (14) to move closer to each other, and pulling the cable (41) by displacement, thereby causing the card head (37) to reset and disengage from the card hole (36), thus making the sealing piston one (13) and the sealing piston four (31) make limiting contact. The structure is under pressure and The structure is unsealed under the action of elastic force; if the sealing body (6) is damaged and leaks during the setting, the leaked fluid is introduced into the location of the inclined hole (4) through the gap between the outer sealing body (1) and the pipe wall. Part of it is diverted through the inclined hole (4) and directed to the position of the turbine blade (19), causing the turbine blade (19) to rotate and causing the small motor (29) to generate a weak and continuous current. The change of this current is monitored to know the fluid leakage situation. Under controllable conditions, the self-healing agent microcapsule (34) outer shell is activated by the micro-starting electrode (35) to cause the internal self-healing agent to leak, thereby sealing the broken gap of the sealing body (6).

2. The bridge plug for oilfield use according to claim 1, characterized in that: The top of the central tube (2) is provided with several slots (3), which are evenly distributed in a circle on the top of the central tube (2). The oblique holes (4) are evenly distributed in a circle on the top of the central tube (2), and the oblique holes (4) are distributed at an angle upward. The top of the outer sealing body (1) is an oblique surface.

3. The bridge plug for oilfield use according to claim 1, characterized in that: The wedge teeth (21) are evenly distributed on the inner side of the sealing body (6) in a circular pattern. The wedge teeth (21) can move through the outer sealing body (1) and extend to the outer side of the central tube (2). The outer side of the tooth sleeve (20) is provided with a beveled groove that matches the wedge teeth (21). The top and bottom ends of the tooth sleeve (20) are fixedly installed with piston rings. The piston rings can move and fit on the opposite sides of the outer sealing body (1) and the central tube (2).

4. The bridge plug for oilfield use according to claim 1, characterized in that: The micro-starting electrode (35) is fixedly installed inside the wedge tooth (21) through a groove. The mounting groove (7) and the sealing body (6) are linearly and evenly distributed on the outside of the top of the outer sealing body (1). Several sealing strips (12) are fixedly sleeved on the outside of the outer sealing body (1). The sealing strips (12) are linearly and evenly distributed on the outside of the outer sealing body (1).

5. The bridge plug for oilfield use according to claim 1, characterized in that: The second mounting groove (8) is evenly distributed around the outside of the outer sealing body (1). The segmented clips (9) are evenly distributed linearly inside the second mounting groove (8). The segmented clips (9) move through the second mounting groove (8) and extend into the inside of the outer sealing body (1). The conical inclined push ring (27) is evenly distributed linearly outside the counterweight column (25). A silicone base pad (26) is fixedly installed at the bottom of the counterweight column (25).

6. The bridge plug for oilfield use according to claim 1, characterized in that: The permanent magnet (14) is movably sleeved inside the central tube (2), and the sealing piston (13) and sealing piston (4) are both movably and sealingly sleeved inside the central tube (2). The permanent magnet (14) and the electromagnet (15) are arranged with their magnetic poles facing each other.

7. The bridge plug for oilfield use according to claim 1, characterized in that: The card hole (36) is opened inside the outer sealing body (1) and the central tube (2). The card hole (36) is evenly distributed in a circle inside the outer sealing body (1) and the central tube (2). The outer side of the card head (37) is rounded. The reset spring (39) is sleeved inside the mounting groove three (38). The opposite ends of the retractable cable (41) are fixedly installed on the opposite end of the card head (37). The retractable cable (41) is movably sleeved through the inner side of the limiting seat ring (40). The opposite end of the retractable cable (41) is fixedly connected to the opposite side of the permanent magnet one (14). The opposite end of the retractable cable (41) is connected to the center of the permanent magnet one (14).

8. The bridge plug for oilfield use according to claim 1, characterized in that: The through holes (22) are evenly distributed in a circle inside the central tube (2). The two ends of the through holes (22) are connected to the inside of the first hydraulic chamber (16) and the bottom of the toothed sleeve (20), respectively. The fixed partition (18) is fixedly sleeved inside the central tube (2). Hydraulic oil is provided on the inner side of both the second hydraulic chamber (23) and the first hydraulic chamber (16).

9. The bridge plug for oilfield use according to claim 1, characterized in that: The outer side of the outer seal (1) is coated with graphene. The opposite sides of the conical inclined push ring (27) and the segmented inclined ring (28) and the opposite sides of the toothed sleeve (20) and the wedge tooth (21) are all coated with molybdenum disulfide wear-resistant coating. The inclination angle between the opposite sides of the conical inclined push ring (27) and the segmented inclined ring (28) and the opposite sides of the toothed sleeve (20) and the wedge tooth (21) is in the range of 12° to 30°.

10. A bridge plug for oilfield use according to claim 1, characterized in that: The top of the sealed piston 2 (17) is fixedly mounted with a control component (30), and the micro sensor group (33) includes temperature, pressure, vibration and displacement sensors.

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