A kind of retrievable bridge plug

Abstract

The invention discloses a retrievable bridge plug, which relates to the field of oil production tools and comprises an upper joint, an upper outer sleeve, an upper piston, a connecting sleeve, a fixed piston, a disjoint ring, a disjoint sleeve, a locking ball seat, a positioning ring, a sealing piston, an upper core tube, an upper locking sleeve, an upper retaining spring, a retaining spring seat, an upper pressure ring, an upper rubber tube, an upper protective ring, an upper outer core tube, an upper cone, an upper pressure cap, a slip sleeve, a slip, a lower cone, a lower pressure cap, an outer core tube, a lower pressure ring, a lower outer core tube, a lower rubber tube, a lower protective ring, a thread plug, a lower retaining spring, a lower spare cap, an upper disjoint pin, an upper steel ball, a lower disjoint pin, a lower steel ball, a fixed pin, an anti-seating pin, an upper single-flow steel ball, an upper single-flow spring, an upper single-flow thread plug, an upper sealing pin, a slip spring, a lower single-flow steel ball, a lower single-flow spring, a lower single-flow thread plug and a lower sealing pin. The retrievable bridge plug of the present invention solves the problems of slip scaling and rusting, reduces the lifting load force, and does not cause damage to the casing.

Description

Technical Field

[0001] The invention relates to the field of oil production tools, in particular to a salvageable bridge plug. Background Art

[0002] As a downhole plugging tool in oil fields, the retrievable bridge plug is a conventional tool in the field of oil production technology. It is widely used in oil and water well stratified fracturing, stratified acidification, and stratified oil testing in oil field exploration and development. It solves the problem of complicated operation of setting, fishing, and unsealing. It is a safe, reliable, low-cost, and fully functional downhole plugging tool. At present, my country's oil wells have entered the middle and late stages of high-water-content exploitation. The water injected into the oil wells has extremely poor stability and is prone to chemical reactions with downhole tools, causing scaling and rusting of the tools, especially for tools such as salvageable bridge plugs. The slips in the bridge plugs are particularly prominent. After reaching their service life in the well, they will scale, rust and corrode. When the salvage tool is lowered to lift the bridge plug, the slips will not be completely recovered, and the slips will still be anchored on the casing wall. The lifting load will increase and the casing wall will also be damaged. Not only does it require the use of a major overhaul and forced extraction operation vehicle, but it also causes irreversible damage to the casing, which will be accompanied by an increase in operating costs. How to ensure that the slips of the salvageable bridge plug can be successfully recovered when unsealed, reduce the lifting load, and not damage the casing is an urgent problem to be solved. Summary of the invention

[0003] The main purpose of the present invention is to provide a retrievable bridge plug, which can effectively solve the problems in the background technology.

[0004] To achieve the above object, the technical solution adopted by the present invention is:

[0005] A retrievable bridge plug comprises an upper joint, an upper outer sleeve, an upper piston, a connecting sleeve, a fixed piston, a disjointed ring, a disjointed sleeve, a locking ball seat, a positioning ring, a setting piston, an upper core tube, an upper locking sleeve, an upper retaining ring, a retaining ring seat, an upper pressure ring, an upper rubber tube, an upper protective ring, an upper outer core tube, an upper cone, an upper pressure cap, a slip sleeve, a slip, a lower cone, a lower pressure cap, an outer core tube, a lower pressure ring, a lower outer core tube, a lower rubber tube, a lower protective ring, a thread plug, a lower retaining ring, a lower retaining ring, a lower disjointed pin, an upper steel Ball, lower disjoint pin, lower steel ball, fixing pin, anti-sitting pin, upper single-flow steel ball, upper single-flow spring, upper single-flow wire plug, upper seating pin, slip spring, lower single-flow steel ball, lower single-flow spring, lower single-flow wire plug, lower seating pin, the first liquid inlet hole, the second liquid inlet hole, the third liquid inlet hole, the fourth liquid inlet hole, the fifth liquid inlet hole, the sixth liquid inlet hole, the seventh liquid inlet hole, the eighth liquid inlet hole, the ninth liquid inlet hole, the tenth liquid inlet hole, the eleventh liquid inlet hole, the twelfth liquid inlet hole.

[0006] The upper joint is connected to the upper piston, the upper outer sleeve is arranged on the upper joint and the outside of the upper piston, the fixed piston is arranged on the outside of the upper joint, the fixed piston is connected to the locking ball seat by threads, the locking ball seat is connected to the upper joint by threads, the upper joint is connected to the upper core tube, the locking ball seat is arranged on the outside of the upper core tube, the locking ball seat and the upper core tube are fixed by the upper steel ball, the disjoint ring is arranged on the outside of the locking ball seat and is fixed by the upper disjoint pin, the retaining spring seat is arranged on the outside of the locking ball seat and is fixed by the lower steel ball, the disjoint sleeve is arranged on the outside of the locking ball seat and the retaining spring seat, the fixed piston is arranged on the outside of the disjoint ring and the disjoint sleeve, the fixed piston and the disjoint sleeve are fixed by the lower disjoint pin, the connecting sleeve is connected to the upper outer sleeve by threads, the connecting sleeve is arranged on the outside of the fixed piston, the positioning ring and the setting piston, the connecting sleeve and the setting piston are fixed by the anti-sitting pin, the positioning ring is arranged on the outside of the retaining spring seat and is fixed by the fixing pin, and the setting piston is arranged on the outside of the retaining spring seat.

[0007] The sealing piston and the locking sleeve are connected by threads, the upper retaining spring is arranged in the outer groove of the retaining spring seat, the upper locking sleeve is arranged on the outside of the retaining spring seat, the upper locking sleeve and the upper pressure ring are connected by threads, the retaining spring seat is provided with a fourth liquid inlet hole and a fifth liquid inlet hole, the fourth liquid inlet hole is connected with the fifth liquid inlet hole, the upper single-flow steel ball and the upper single-flow spring are placed in the fifth liquid inlet hole, the upper single-flow wire plug and the retaining spring seat are connected by threads, and the upper single-flow steel ball is pressed on the conical surface of the fifth liquid inlet hole by the elastic force of the upper single-flow spring and is sealed.

[0008] The retaining ring seat is connected to the outer core tube by threads, the upper outer core tube is sleeved on the outside of the outer core tube, the upper pressure ring is connected to the upper outer core tube by threads, the upper rubber tube is sleeved on the outside of the upper outer core tube, the upper protective ring is connected to the upper cone by threads and sleeved on the outside of the upper outer core tube, the upper outer core tube and the upper cone are fixed by the upper sealing pin, the slip sleeve is arranged on the outside of the outer core tube, the upper cone and the lower cone are sleeved on the outside of the outer core tube, the upper cone and the lower cone are supported on the inclined surfaces at both ends of the slip, the slip sleeve is sleeved on the outside of the upper cone, the slip and the lower cone, the upper pressure cap, the lower pressure cap and the slip sleeve are connected by threads, the slip spring is placed in the outer groove of the slip, and the two ends of the slip spring are supported on the inner surface of the slip sleeve and the outer surface of the slip.

[0009] The lower pressure ring is connected to the lower cone by threads and is sleeved on the outside of the lower outer core tube, the lower rubber tube is sleeved on the outside of the lower outer core tube, the lower guard ring is connected to the lower outer core tube by threads, the lower guard ring is connected to the lower spare cap and fixed by the lower sealing pin, the lower outer core tube and the lower guard ring are sleeved on the outside of the outer core tube, the lower spare cap and the outer core tube are connected by threads, the lower retaining spring is sleeved in the outer groove of the lower spare cap, the wire plug is connected to the locking ball seat by threads, the outer core tube is sleeved on the locking ball seat and the outside of the wire plug, the outer cylindrical surface of the lower guard ring is provided with a tenth liquid inlet hole, the lower single-flow steel ball and the lower single-flow spring are placed in the tenth liquid inlet hole, the lower single-flow wire plug is connected to the lower guard ring by threads, and the lower single-flow steel ball is pressed against the cone surface of the tenth liquid inlet hole by the elastic force of the lower single-flow spring and is sealed.

[0010] The upper joint is provided with a first liquid inlet hole, the upper core tube is provided with a second liquid inlet hole, the locking ball seat is provided with a third liquid inlet hole, the retaining spring seat is provided with a fourth liquid inlet hole, the retaining spring seat is provided with a fifth liquid inlet hole, the upper outer core tube is provided with a sixth liquid inlet hole, the upper cone is provided with a seventh liquid inlet hole, the lower cone is provided with an eighth liquid inlet hole, the lower outer core tube is provided with a ninth liquid inlet hole, the lower guard ring is provided with a tenth liquid inlet hole, the locking ball seat is provided with an eleventh liquid inlet hole, the locking ball seat is provided with an eleventh liquid inlet hole, and the outer core tube is provided with a twelfth liquid inlet hole.

[0011] The upper joint and the upper outer sleeve, the upper piston, the fixed piston and the upper core tube are sealed by a sealing ring; the lock ball seat and the fixed piston, the disjointed sleeve, the upper core tube and the retaining spring seat are sealed by a sealing ring; the setting piston and the connecting sleeve and the retaining spring seat are sealed by a sealing ring; the upper locking sleeve and the retaining spring seat and the upper pressure ring are sealed by a sealing ring; the retaining spring seat and the outer core tube are sealed by a sealing ring; the upper outer core tube and the upper cone and the outer core tube are sealed by a sealing ring; the upper guard ring and the upper cone are sealed by a sealing ring; the outer core tube and the lower guard ring, the thread plug and the lower spare cap are sealed by a sealing ring; the lower guard ring and the lower spare cap are sealed by a sealing ring; the lock ball seat and the thread plug are sealed by a sealing ring.

[0012] The lock ball seat, the upper core tube and the thread plug are sealed by a sealing ring, and the formed sealing cavity is filled with hydraulic oil.

[0013] Working principle of the present invention:

[0014] The retrievable bridge plug provided by the present invention is connected to the oil pipe string and lowered into the oil well. The operation process is as follows:

[0015] Sealing process:

[0016] The present invention is connected to the oil pipe column and lowered to a predetermined position. The ground pump truck pressurizes the oil pipe, and water enters the first liquid inlet hole, the second liquid inlet hole, and the third liquid inlet hole of the bridge plug through the oil pipe. The water pushes the upper piston through the first liquid inlet hole, and the upper piston drives the upper outer sleeve to push the connecting sleeve, the sealing piston, the upper locking sleeve, the upper pressure ring, the upper protective ring, the upper outer core tube, and the upper cone downward. The upper rubber cylinder is compressed, and the upper cone pushes the slip to expand outward, pressurized to the rated pressure, the upper sealing pin is sheared off, the upper outer core tube moves downward, and the hole centers of the sixth liquid inlet hole and the seventh liquid inlet hole coincide to form a liquid flow channel. At the same time, water pushes the disjoint sleeve through the second liquid inlet hole and the third liquid inlet hole, and pressurized to the rated pressure. The lower disjoint pin is sheared off, and the disjoint The sleeve moves up to the end face of the disjointed ring, the lower steel ball loses the support of the disjointed sleeve, the locking ball seat and the retaining spring seat are in a free state, and the pressure is continued to be increased to the rated pressure, the upper disjointed pin is cut off, and the disjointed sleeve pushes the disjointed ring to move up to the end face of the fixed piston, the upper steel ball loses the support of the disjointed ring, the locking ball seat and the upper core tube are in a free state, and the pressure is continued to be increased to the rated pressure, the upper core tube is disengaged from the locking ball seat, the upper core tube moves down to push the hydraulic oil in the sealing cavity through the eleventh and twelfth liquid inlet holes, and the pressure is increased to the rated pressure, the lower sealing pin is cut off, the lower guard ring moves up, the lower outer core tube, the lower pressure ring, and the lower cone move up, the lower rubber cylinder is compressed, and the lower cone pushes the slips to expand outwards. At this time, the slips are in the upper and lower cones. The lower expansion is pushed and anchored on the casing wall. There is well fluid in the space after the upper and lower rubber cylinders are compressed and expanded. The slips are anchored in this space. During the pressurization process, the hydraulic oil in the closed cavity enters the annular space between the lock ball seat, the retaining spring seat and the outer core tube through the eleventh liquid inlet hole, pushes the upper single-flow steel ball through the fourth and fifth liquid inlet holes, compresses the upper single-flow spring, and enters the space after the upper and lower rubber cylinders are compressed and expanded through the sixth and seventh liquid inlet holes. Under the action of pressure, the well fluid in this space is squeezed out and discharged through the eighth, ninth and tenth liquid inlet holes. When the pressure is stopped, the upper single-flow spring pushes the upper single-flow steel ball to close the fifth liquid inlet hole, and the lower single-flow The spring pushes the lower single-flow steel ball to close the tenth liquid inlet hole. The space after the upper rubber cylinder and the lower rubber cylinder are compressed and sealed is filled with hydraulic oil and forms a closed space. The upper cone, slips and lower cone will not scale or rust in this space. The bridge plug is unsealed smoothly and does not get stuck in the well. When the pressure reaches the rated pressure, the inner and outer teeth of the upper locking sleeve and the upper retaining ring, and the inner and outer teeth of the lower retaining ring and the lower retaining ring are all clamped and locked. The upper rubber cylinder, slips and lower rubber cylinder are sealed and anchored. The oil pipe string is lifted, and the anti-sitting pin is sheared off, driving the upper joint, upper outer sleeve, upper piston, connecting sleeve, fixed piston, disjoint ring, disjoint sleeve, locking ball seat, upper core pipe and thread plug to move upward and be lifted to the ground with the pipe string. At this time, the bridge plug seating process is completed.

[0017] Unblocking process:

[0018] When unsealing, the upper retaining ring seat is lifted to drive the upper locking sleeve, the upper retaining ring, the upper pressure ring and the upper outer core tube upward, the upper rubber tube is released and recovered, and the upper outer core tube moves upward to the end face of the upper guard ring and drives the upper cone upward. The slips are released and recovered to their original position after losing the support of the upper cone. At the same time, the lower cone and the lower rubber tube will be released after losing the support of the slips, and the lower rubber tube is released and recovered. The upper rubber tube, slips and lower rubber tube are all restored to their original positions, and the lifting continues to be carried out to lift out the bridge plug. The slips are in the closed cavity of the hydraulic oil and will not scale or rust when working underground. They can easily shrink to their original position when unsealing. When lifting the tubing string, the slips will not scratch the casing and the well will not be stuck. The lifting load is reduced, and the bridge plug is easy and safe to unseal.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] A retrievable bridge plug utilizes the anti-corrosion and anti-rust characteristics of hydraulic oil and combines the unique design structure of the present invention to squeeze the hydraulic oil into the sealing cavity of the rubber cylinder and slips, ensuring that the slips do not come into contact with the well fluid when working underground, solving the problem of slips scaling and rusting that lead to incomplete unsealing and recovery. At the same time, the anchoring performance of the slips and the sealing performance of the rubber cylinder also meet the working needs. The overall structural design is novel and the operation is simple and convenient.

[0021] The ball lock seat, the upper core tube and the plug are sealed by a sealing ring, and the sealing cavity formed is filled with hydraulic oil. When setting, the lower setting pin is pressed, the upper and lower rubber cylinders are compressed and sealed, and the slips are also anchored on the casing wall. There is well fluid in the closed space formed by the upper and lower rubber cylinders. As the well fluid in this space is squeezed out by the hydraulic oil, the slips are covered by the hydraulic oil to protect the slips from scaling and rust. When the bridge plug is unsealed, the upper rubber cylinder, slips and lower rubber cylinder are restored to their original positions, the slips will not scratch the casing, the well will not be stuck, the lifting load is reduced, and the bridge plug is easy and safe to unseal. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of a retrievable bridge plug of the present invention;

[0023] Figure 1Middle: 1. Upper joint, 2. Upper outer sleeve, 3. Upper piston, 4. Connecting sleeve, 5. Fixed piston, 6. Disconnecting ring, 7. Disconnecting sleeve, 8. Lock ball seat, 9. Positioning ring, 10. Setting piston, 11. Upper core tube, 12. Upper locking sleeve, 13. Upper retaining ring, 14. Retaining ring seat, 15. Upper pressure ring, 16. Upper rubber cylinder, 17. Upper protective ring, 18. Upper outer core tube, 19. Upper cone, 20. Upper pressure cap, 21. Slip sleeve, 22. Slip, 23. Lower cone, 24. Lower pressure cap, 25. Outer core tube, 26. Lower pressure ring, 27. Lower outer core tube, 28. Lower rubber cylinder, 29. Lower protective ring, 30. Screw plug, 31. Lower retaining ring, 32. Lower spare cap, 33. Upper disconnecting pin, 34. Upper steel ball, 35. Lower disjoint pin, 36. Lower steel ball, 37. Fixed pin, 38. Anti-sitting pin, 39. Upper single-flow steel ball, 40. Upper single-flow spring, 41. Upper single-flow wire plug, 42. Upper seating pin, 43. Cava spring, 44. Lower single-flow steel ball, 45. Lower single-flow spring, 46. Lower single-flow wire plug, 47. Lower seating pin, 48. First liquid inlet hole, 49. Second liquid inlet hole, 50. Third liquid inlet hole, 51. Fourth liquid inlet hole, 52. Fifth liquid inlet hole, 53. Sixth liquid inlet hole, 54. Seventh liquid inlet hole, 55. Eighth liquid inlet hole, 56. Ninth liquid inlet hole, 57. Tenth liquid inlet hole, 58. Eleventh liquid inlet hole, 59. Twelfth liquid inlet hole. DETAILED DESCRIPTION

[0024] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0025] like Figure 1As shown, a retrievable bridge plug comprises an upper joint 1, an upper outer sleeve 2, an upper piston 3, a connecting sleeve 4, a fixed piston 5, a disjoint ring 6, a disjoint sleeve 7, a locking ball seat 8, a positioning ring 9, a setting piston 10, an upper core tube 11, an upper locking sleeve 12, an upper retaining ring 13, a retaining ring seat 14, an upper pressure ring 15, an upper rubber cylinder 16, an upper protective ring 17, an upper outer core tube 18, an upper cone 19, an upper pressure cap 20, a slip sleeve 21, a slip 22, a lower cone 23, a lower pressure cap 24, an outer core tube 25, a lower pressure ring 26, a lower outer core tube 27, a lower rubber cylinder 28, a lower protective ring 29, a thread plug 30, a lower retaining ring 31, a lower spare cap 32, and an upper disjoint pin 3 3, upper steel ball 34, lower disjoint pin 35, lower steel ball 36, fixing pin 37, anti-seating pin 38, upper single-flow steel ball 39, upper single-flow spring 40, upper single-flow wire plug 41, upper sealing pin 42, slip spring 43, lower single-flow steel ball 44, lower single-flow spring 45, lower single-flow wire plug 46, lower sealing pin 47, first liquid inlet hole 48, second liquid inlet hole 49, third liquid inlet hole 50, fourth liquid inlet hole 51, fifth liquid inlet hole 52, sixth liquid inlet hole 53, seventh liquid inlet hole 54, eighth liquid inlet hole 55, ninth liquid inlet hole 56, tenth liquid inlet hole 57, eleventh liquid inlet hole 58, twelfth liquid inlet hole 59.

[0026] The upper joint 1 is connected to the upper piston 3, the upper sleeve 2 is sleeved on the upper joint 1 and the outer part of the upper piston 3, the fixed piston 5 is sleeved on the outer part of the upper joint 1, the fixed piston 5 is connected to the lock ball seat 8 by a thread, the lock ball seat 8 is connected to the upper joint 1 by a thread, the upper joint 1 is connected to the upper core tube 11, the lock ball seat 8 is sleeved on the outer part of the upper core tube 11, the lock ball seat 8 and the upper core tube 11 are fixed by the upper steel ball 34, the disengagement ring 6 is sleeved on the outer part of the lock ball seat 8 and fixed by the upper disengagement pin 33, the retaining ring seat 14 is sleeved on the outer part of the lock ball seat 8 and fixed by the lower steel ball 3 6 is fixed, the disjoint sleeve 7 is sleeved on the outside of the lock ball seat 8 and the retaining spring seat 14, the fixed piston 5 is sleeved on the outside of the disjoint ring 6 and the disjoint sleeve 7, the fixed piston 5 and the disjoint sleeve 7 are fixed by the lower disjoint pin 35, the connecting sleeve 4 and the upper outer sleeve 2 are connected by threads, the connecting sleeve 4 is sleeved on the outside of the fixed piston 5, the positioning ring 9 and the setting piston 10, the connecting sleeve 4 and the setting piston 10 are fixed by the anti-sitting pin 38, the positioning ring 9 is sleeved on the outside of the retaining spring seat 14 and fixed by the fixing pin 37, and the setting piston 10 is sleeved on the outside of the retaining spring seat 14.

[0027] The sealing piston 10 is connected to the locking sleeve 12 by threads, the upper retaining spring 13 is sleeved in the outer groove of the retaining spring seat 14, the upper locking sleeve 12 is sleeved on the outside of the retaining spring seat 14, the upper locking sleeve 12 is connected to the upper pressure ring 15 by threads, the retaining spring seat 14 is provided with a fourth liquid inlet hole 51 and a fifth liquid inlet hole 52, the fourth liquid inlet hole 51 is connected to the fifth liquid inlet hole 52, the upper single-flow steel ball 39 and the upper single-flow spring 40 are placed in the fifth liquid inlet hole 52, the upper single-flow wire plug 41 is connected to the retaining spring seat 14 by threads, and the upper single-flow steel ball 39 is pressed against the conical surface of the fifth liquid inlet hole 52 by the elastic force of the upper single-flow spring 40 and is sealed.

[0028] The retaining ring 14 is connected to the outer core tube 25 by threads, the upper outer core tube 18 is sleeved on the outer core tube 25, the upper pressure ring 15 is connected to the upper outer core tube 18 by threads, the upper rubber tube 16 is sleeved on the outer core tube 18, the upper guard ring 17 is connected to the upper cone 19 by threads and sleeved on the outer core tube 18, the upper outer core tube 18 and the upper cone 19 are fixed by the upper sealing pin 42, the slip 22 is sleeved on the outer core tube 25, and the upper cone The body 19 and the lower cone 23 are sleeved on the outside of the outer core tube 25, the upper cone 19 and the lower cone 23 are supported on the inclined surfaces at both ends of the slip 22, the slip sleeve 21 is sleeved on the outside of the upper cone 19, the slip 22 and the lower cone 23, the upper pressure cap 20 and the lower pressure cap 24 are connected to the slip sleeve 21 by threads, the slip spring 43 is placed in the outer groove of the slip 22, and the two ends of the slip spring 43 are supported on the inner surface of the slip sleeve 21 and the outer surface of the slip 22.

[0029] The lower pressure ring 26 is connected to the lower cone 23 by threads and is sleeved on the outside of the lower outer core tube 27. The lower rubber tube 28 is sleeved on the outside of the lower outer core tube 27. The lower protective ring 29 is connected to the lower outer core tube 27 by threads. The lower protective ring 29 is connected to the lower reserve cap 32 and fixed by the lower sealing pin 47. The lower outer core tube 27 and the lower protective ring 29 are sleeved on the outside of the outer core tube 25. The lower reserve cap 32 is connected to the outer core tube 25 by threads. The lower retaining ring 31 is sleeved on the lower reserve cap. 32 outer groove, the wire plug 30 is connected to the lock ball seat 8 by threads, the outer core tube 25 is sleeved on the lock ball seat 8 and the outside of the wire plug 30, the outer cylindrical surface of the lower protective ring 29 is provided with a tenth liquid inlet hole 57, the lower single-flow steel ball 44 and the lower single-flow spring 45 are placed in the tenth liquid inlet hole 57, the lower single-flow wire plug 46 is connected to the lower protective ring 29 by threads, and the lower single-flow steel ball 44 is pressed against the conical surface of the tenth liquid inlet hole 57 by the elastic force of the lower single-flow spring 45 and is sealed.

[0030] The upper joint 1 is provided with a first liquid inlet hole 48, the upper core tube 11 is provided with a second liquid inlet hole 49, the lock ball seat 8 is provided with a third liquid inlet hole 50, the retaining spring seat 14 is provided with a fourth liquid inlet hole 51, the retaining spring seat 14 is provided with a fifth liquid inlet hole 52, the upper outer core tube 18 is provided with a sixth liquid inlet hole 53, the upper cone 19 is provided with a seventh liquid inlet hole 54, the lower cone 23 is provided with an eighth liquid inlet hole 55, the lower outer core tube 27 is provided with a ninth liquid inlet hole 56, the lower guard ring 29 is provided with a tenth liquid inlet hole 57, the lock ball seat 8 is provided with an eleventh liquid inlet hole 58, and the outer core tube 25 is provided with a twelfth liquid inlet hole 59.

[0031] The upper joint 1 is sealed with the upper outer sleeve 2, the upper piston 3, the fixed piston 5, and the upper core tube 11 by a sealing ring; the lock ball seat 8 is sealed with the fixed piston 5, the disengagement sleeve 7, the upper core tube 11, and the retaining spring seat 14 by a sealing ring; the setting piston 10 is sealed with the connecting sleeve 4 and the retaining spring seat 14 by a sealing ring; the upper locking sleeve 12 is sealed with the retaining spring seat 14 and the upper pressure ring 15 by a sealing ring; the retaining spring seat 14 and the outer core tube 25 are sealed by a sealing ring; the upper outer core tube 18 is sealed with the upper cone 19 and the outer core tube 25 by a sealing ring; the upper guard ring 17 and the upper cone 19 are sealed by a sealing ring; the outer core tube 25 is sealed with the lower guard ring 29, the thread plug 30, and the lower spare cap 32 by a sealing ring; the lower guard ring 29 and the lower spare cap 32 are sealed by a sealing ring; the lock ball seat 8 and the thread plug 30 are sealed by a sealing ring.

[0032] The locking ball seat 8, the upper core tube 11 and the thread plug 30 are sealed by a sealing ring, and the formed sealing cavity is filled with hydraulic oil.

[0033] When sealing, the present invention is connected to the oil pipe column and lowered to a predetermined position. The ground pump truck pressurizes the oil pipe, and water enters the first liquid inlet hole 48, the second liquid inlet hole 49, and the third liquid inlet hole 50 of the bridge plug through the oil pipe. The water pushes the piston 3 through the first liquid inlet hole 48, and the upper piston 3 drives the upper outer sleeve 2 to push the connecting sleeve 4, the sealing piston 10, the upper locking sleeve 12, the upper pressure ring 15, the upper retaining ring 17, the upper outer core tube 18, and the upper cone 19 downward. The upper rubber cylinder 16 is compressed, and the upper cone 19 pushes the slip 22 outward to expand and pressurize to the rated pressure. The upper sealing pin 42 is sheared off, and the upper outer core tube 18 moves downward. The hole centers of the sixth liquid inlet hole 53 and the seventh liquid inlet hole 54 coincide to form a liquid flow channel. At the same time, water pushes the disconnection sleeve 7 through the second liquid inlet hole 49 and the third liquid inlet hole 50. , pressurized to the rated pressure, the lower disjointed pin 35 is sheared off, the disjointed sleeve 7 moves up to the end face of the disjointed ring 6, the lower steel ball 36 loses the support of the disjointed sleeve 7, the locking ball seat 8 and the retaining spring seat 14 are in a free state, continue to pressurize to the rated pressure, cut off the upper disjointed pin 33, the disjointed sleeve 7 pushes the disjointed ring 6 up to the end face of the fixed piston 5, the upper steel ball 34 loses the support of the disjointed ring 6, the locking ball seat 8 and the upper core tube 11 are in a free state, continue to pressurize to the rated pressure, the upper core tube 11 is disengaged from the locking ball seat 8, the upper core tube 11 moves downward to push the hydraulic oil in the sealing cavity through the eleventh liquid inlet hole 58 and the twelfth liquid inlet hole 59, pressurized to the rated pressure, cut off the lower sealing pin 47, the lower retaining ring 29 moves upward, pushes the lower outer core tube 27, the lower pressure ring 26, and the lower cone 23 upward The lower rubber cylinder 28 is compressed, and the lower cone 23 pushes the slip 22 to expand outward. At this time, the slip 22 is expanded and anchored on the casing wall under the push of the upper cone 19 and the lower cone 23. There is well fluid in the space after the upper rubber cylinder 16 and the lower rubber cylinder 28 are compressed and expanded. The slip 22 is anchored in this space. During the pressurization process, the hydraulic oil in the closed cavity passes through the eleventh liquid inlet hole 58, enters the annular space between the lock ball seat 8, the retaining spring seat 14, and the outer core tube 25, and pushes the upper single-flow steel ball 39 through the fourth liquid inlet hole 51 and the fifth liquid inlet hole 52, compresses the upper single-flow spring 40, and enters the space after the upper rubber cylinder 16 and the lower rubber cylinder 28 are compressed and expanded through the sixth liquid inlet hole 53 and the seventh liquid inlet hole 54. Under the action of pressure, the well fluid in this space is squeezed out and passes through the eighth liquid inlet hole. The liquid hole 55, the ninth liquid inlet hole 56, and the tenth liquid inlet hole 57 discharge the well fluid. When the pressure is stopped, the upper single-flow spring 40 pushes the upper single-flow steel ball 39 to close the fifth liquid inlet hole 52, and the lower single-flow spring 45 pushes the lower single-flow steel ball 44 to close the tenth liquid inlet hole 57. The space after the upper rubber cylinder 16 and the lower rubber cylinder 28 are compressed and sealed is filled with hydraulic oil and forms a closed space. The upper cone 19, the slip 22, and the lower cone 23 will not scale or rust in this space. The bridge plug is unsealed smoothly without getting stuck in the well. When the pressure reaches the rated pressure, the inner and outer teeth of the upper locking sleeve 12 and the upper retaining ring 13, and the inner and outer teeth of the lower retaining ring 29 and the lower retaining ring 31 are all locked and locked. The upper rubber cylinder 16, the slip 22, and the lower rubber cylinder 28 are sealed and anchored. The oil pipe string is lifted, and the anti-sitting pin 38 is sheared off.The upper joint 1, upper outer sleeve 2, upper piston 3, connecting sleeve 4, fixed piston 5, disconnecting ring 6, disconnecting sleeve 7, locking ball seat 8, upper core pipe 11, and screw plug 30 are driven upward and lifted to the ground along with the pipe string. At this time, the bridge plug setting process is completed.

[0034] When unsealing, the upper retaining ring seat 14 is lifted up to drive the upper locking sleeve 12, the upper retaining ring 13, the upper pressure ring 15, and the upper outer core tube 18 to move upward, and the upper rubber tube 16 is released and recovered. After the upper outer core tube 18 moves upward to the end face of the upper retaining ring 17, it drives the upper cone 19 to move upward. The slips 22 are released and recovered to their original positions after losing the support of the upper cone 19. At the same time, the lower cone 23 and the lower rubber tube 28 are released after losing the support of the slips 22, and the lower rubber tube 28 is released and recovered. The upper rubber tube 16, the slips 22, and the lower rubber tube 28 are all restored to their original positions, and the bridge plug is continuously lifted up to be taken out. The slips 22 are in the closed cavity of the hydraulic oil and will not scale or rust when working underground. They can easily shrink to their original positions when unsealing. When lifting the tubing string, the slips 22 will not scratch the casing and will not get stuck in the well. The lifting load is reduced, and the bridge plug is easy and safe to unseal.

Claims

1. A retrievable bridge plug, characterized in that: The utility model comprises an upper joint (1), an upper outer sleeve (2), an upper piston (3), a connecting sleeve (4), a fixed piston (5), a disjointed ring (6), a disjointed sleeve (7), a locking ball seat (8), a positioning ring (9), a setting piston (10), an upper core tube (11), an upper locking sleeve (12), an upper retaining ring (13), a retaining ring seat (14), an upper pressure ring (15), an upper rubber cylinder (16), an upper protective ring (17), an upper outer core tube (18), an upper cone (19), an upper pressure cap (20), a slip sleeve (21), a slip (22), a lower cone (23), a lower pressure cap (24), an outer core tube (25), a lower pressure ring (26), a lower outer core tube (27), a lower rubber cylinder (28), a lower protective ring (29), a thread plug (30), a lower retaining ring (31), a lower spare cap (32), upper disjointed pin (33), upper steel ball (34), lower disjointed pin (35), lower steel ball (36), fixing pin (37), anti-seating pin (38), upper single-flow steel ball (39), upper single-flow spring (40), upper single-flow wire plug (41), upper sealing pin (42), slip spring (43), lower single-flow steel ball (44), lower single-flow spring (45), lower single-flow wire plug (46), lower sealing pin (47), first liquid inlet hole (48), second liquid inlet hole (49), third liquid inlet hole (50), fourth liquid inlet hole (51), fifth liquid inlet hole (52), sixth liquid inlet hole (53), seventh liquid inlet hole (54), eighth liquid inlet hole (55), ninth liquid inlet hole (56), tenth liquid inlet hole ( 57), an eleventh liquid inlet hole (58), a twelfth liquid inlet hole (59), the upper joint (1) is connected to the upper piston (3), the upper outer sleeve (2) is sleeved on the upper joint (1) and the outer portion of the upper piston (3), the fixed piston (5) is sleeved on the outer portion of the upper joint (1), the fixed piston (5) is connected to the locking ball seat (8) by a thread, the locking ball seat (8) is connected to the upper joint (1) by a thread, the upper joint (1) is connected to the upper core tube (11), the locking ball seat (8) is sleeved on the outer portion of the upper core tube (11), the locking ball seat (8) and the upper core tube (11) are fixed by an upper steel ball (34), the disengagement ring (6) is sleeved on the outer portion of the locking ball seat (8) and fixed by an upper disengagement pin (33), the retaining spring seat (14) is sleeved on The locking ball seat (8) is externally mounted and fixed by a lower steel ball (36); the disengagement sleeve (7) is sleeved on the locking ball seat (8) and the externally mounted on the retaining spring seat (14); the fixed piston (5) is sleeved on the externally mounted on the disengagement ring (6) and the externally mounted on the disengagement sleeve (7); the fixed piston (5) and the disengagement sleeve (7) are fixed by a lower disengagement pin (35); the connecting sleeve (4) and the upper outer sleeve (2) are connected by threads; the connecting sleeve (4) is sleeved on the externally mounted on the fixed piston (5), the positioning ring (9) and the externally mounted on the setting piston (10); the connecting sleeve (4) and the externally mounted on the setting piston (10) are fixed by an anti-seating pin (38); the positioning ring (9) is sleeved on the externally mounted on the retaining spring seat (14) and fixed by a fixing pin (37); the setting piston (10) is sleeved on the externally mounted on the retaining spring seat (14);The sealing piston (10) is connected to the upper locking sleeve (12) by threads, the upper retaining spring (13) is sleeved in the outer groove of the retaining spring seat (14), the upper locking sleeve (12) is sleeved outside the retaining spring seat (14), the upper locking sleeve (12) is connected to the upper pressure ring (15) by threads, the retaining spring seat (14) is provided with a fourth liquid inlet hole (51) and a fifth liquid inlet hole (52), the fourth liquid inlet hole (51) is communicated with the fifth liquid inlet hole (52), the upper single-flow steel ball (39) and the upper single-flow spring (40) are placed in the fifth liquid inlet hole (52), the upper single-flow wire plug (41) is connected to the retaining spring seat (14) by threads, the upper single-flow steel ball (39) is pressed against the conical surface of the fifth liquid inlet hole (52) by the elastic force of the upper single-flow spring (40) and The invention relates to a sealing device, wherein the retaining spring seat (14) is connected to the outer core tube (25) by threads, the upper outer core tube (18) is sleeved on the outside of the outer core tube (25), the upper pressure ring (15) is connected to the upper outer core tube (18) by threads, the upper rubber tube (16) is sleeved on the outside of the upper outer core tube (18), the upper protective ring (17) is connected to the upper cone (19) by threads and sleeved on the outside of the upper outer core tube (18), the upper outer core tube (18) and the upper cone (19) are fixed by an upper sealing pin (42), the slip (22) is sleeved on the outside of the outer core tube (25), the upper cone (19) and the lower cone (23) are sleeved on the outside of the outer core tube (25), the upper cone (19) and the lower cone (23) are supported on the inclined surfaces at both ends of the slip (22), and the sealing device is provided with a sealing device. The slip sleeve (21) is sleeved on the outside of the upper cone (19), the slip (22) and the lower cone (23); the upper pressure cap (20), the lower pressure cap (24) and the slip sleeve (21) are connected by threads; the slip spring (43) is placed in the outer groove of the slip (22); the two ends of the slip spring (43) are supported on the inner surface of the slip sleeve (21) and the outer surface of the slip (22); the lower pressure ring (26) is connected to the lower cone (23) by threads and sleeved on the outside of the lower outer core tube (27); the lower rubber cylinder (28) is sleeved on the outside of the lower outer core tube (27); the lower guard ring (29) is connected to the lower outer core tube (27) by threads; the lower guard ring (29) is connected to the lower reserve cap (32) and is fixed by the lower sealing pin (47); the lower outer core tube (27), the lower guard ring (29) is sleeved on the outside of the outer core tube (25), the lower reserve cap (32) is connected to the outer core tube (25) by threads, the lower retaining ring (31) is sleeved in the outer groove of the lower reserve cap (32), the thread plug (30) is connected to the lock ball seat (8) by threads, the outer core tube (25) is sleeved on the lock ball seat (8) and the outside of the thread plug (30), the outer cylindrical surface of the lower guard ring (29) is provided with a tenth liquid inlet hole (57), the lower single-flow steel ball (44) and the lower single-flow spring (45) are placed in the tenth liquid inlet hole (57), the lower single-flow thread plug (46) is connected to the lower guard ring (29) by threads, and the lower single-flow steel ball (44) is pressed against the conical surface of the tenth liquid inlet hole (57) by the elastic force of the lower single-flow spring (45) and is sealed.

2. A retrievable bridge plug according to claim 1, characterized in that: The upper joint (1) is provided with a first liquid inlet hole (48), the upper core tube (11) is provided with a second liquid inlet hole (49), the locking ball seat (8) is provided with a third liquid inlet hole (50), the retaining spring seat (14) is provided with a fourth liquid inlet hole (51), the retaining spring seat (14) is provided with a fifth liquid inlet hole (52), the upper outer core tube (18) is provided with a sixth liquid inlet hole (53), the upper cone (19) is provided with a seventh liquid inlet hole (54), the lower cone (23) is provided with an eighth liquid inlet hole (55), the lower outer core tube (27) is provided with a ninth liquid inlet hole (56), the lower guard ring (29) is provided with a tenth liquid inlet hole (57), the locking ball seat (8) is provided with an eleventh liquid inlet hole (58), and the outer core tube (25) is provided with a twelfth liquid inlet hole (59).

3. The retrievable bridge plug according to claim 1, characterized in that: The locking ball seat (8), the upper core tube (11) and the thread plug (30) are sealed by a sealing ring, and the formed sealing cavity is filled with hydraulic oil.

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