Composite fast drilling water injection packer and its operation method

Abstract

The application discloses a composite rapid drilling type water injection packer and an operation method thereof. The composite rapid drilling type water injection packer comprises a setting upper joint, a public thread and a female thread are arranged at the lower end of the setting upper joint, an upper central pipe is rotatably connected to the female thread of the setting upper joint, a lower central pipe is rotatably connected to the lower end of the upper central pipe, a setting lower joint is rotatably connected to the lower end of the lower central pipe, a setting mechanism is arranged at the outer periphery of the upper central pipe, and a setting driving mechanism is arranged below the setting mechanism. The water injection packer further comprises a backwashing mechanism capable of flushing dirt and a releasing mechanism capable of separating an upper pipe column. The operation steps comprise setting, backwashing and unsetting. When unsetting fails, the upper pipe column can be released, the lower sleeve milling head is sleeved and milled after the releasing, the rubber cylinder is rebounded to complete unsetting, and then the well tool is fished. The water injection packer can overcome the problem that the upper pipe column cannot be lifted when the water injection pipe column fails, the scaling and fishing of the packer are facilitated, the overhaul is avoided, the operation cycle is saved, and the cost is reduced.

Description

Technical Field

[0001] This invention relates to a packer for oil and gas well operations, and more particularly to a composite fast-drilling water injection packer. This invention also relates to a method for operating the composite fast-drilling water injection packer, belonging to the technical field of downhole water injection tools. Background Technology

[0002] In the later stages of oilfield development, water injection is an effective means of replenishing formation energy. However, due to differences in formation energy, it is necessary to isolate different formations for stratified water injection. This stratified water injection requires a key tool: the water packer, to achieve stratified and quantitative water distribution. From the perspective of the driving mechanism, packers can be divided into mechanical or hydraulic types.

[0003] Chinese utility model patent CN 219299256U discloses a packer release structure and a packer. The packer release structure includes: a release block connected to the packer body via a release pin; a release section fitted inside the release block and coaxially connected to a self-compensating oil pipe, the outer wall of the release section having an assembly groove; a locking block disposed in the assembly groove for axially limiting the release block in the release section, the shearing force of the locking block being greater than the shearing force of the release pin; and a support block disposed in the assembly groove for providing radial support to the locking block along the release section, the support block being heat-meltable, and when the support block is heat-melted, the locking block can detach from the release block.

[0004] When this packer is used for downhole water injection, the scale buildup on top of the packer slowly falls onto the upper part of the packer's rubber sleeve. This makes it very difficult to unseal the packer with scale buildup when the water injection string fails and needs to be pulled up. It often requires major repairs, which is time-consuming, labor-intensive, and too costly. Summary of the Invention

[0005] The primary objective of this invention is to provide a composite quick-drilling water injection packer that overcomes the problem of being unable to be lifted when the water injection tubing fails, facilitates the removal of scale and retrieval of the packer, avoids major repairs, saves operating time, and reduces costs.

[0006] To solve the above technical problems, the present invention provides a composite rapid drilling type water injection packer, comprising:

[0007] The upper part of the seat is equipped with male and female threads at the lower end;

[0008] The upper center tube is screwed into the female thread of the upper joint on the seat seal;

[0009] The lower center tube is screwed to the lower end of the upper center tube;

[0010] The lower connector is set, and its upper end is screwed onto the lower end of the lower central tube;

[0011] The sealing mechanism is located on the outer periphery of the upper central tube;

[0012] The setting drive mechanism is located below the setting mechanism.

[0013] As an improvement of the present invention, the setting mechanism includes:

[0014] The outer central tube is fitted around the outer periphery of the upper central tube and there are annular channels between them;

[0015] The rubber sleeve is segmented and fitted around the outer periphery of the outer central tube;

[0016] Spacer rings are located between adjacent rubber cylinders.

[0017] As a further improvement of the present invention, the setting and driving mechanism includes:

[0018] The upper hydraulic cylinder is fitted onto the lower outer periphery of the upper central tube, and its inner periphery, together with the upper and lower central tubes, forms the upper hydraulic cavity.

[0019] The lower hydraulic cylinder is fitted onto the lower outer periphery of the lower central tube, and its inner periphery, together with the lower central tube and the lower seat seal joint, forms the lower hydraulic chamber.

[0020] The lower circumference of the upper central tube is provided with an upper injection hole communicating with the upper hydraulic chamber, and the lower circumference of the lower central tube is provided with a lower injection hole communicating with the lower hydraulic chamber.

[0021] As a further improvement of the present invention, the upper end of the lower central tube is located below the inner step of the upper liquid cylinder, and the upper outer periphery of the lower central tube is sealed to the cylinder sleeve of the upper liquid cylinder by an O-ring.

[0022] As a further improvement of the present invention, the top of the lower setting joint abuts against the inner step of the lower liquid cylinder, and the upper outer periphery of the lower setting joint is sealed to the cylinder liner of the lower liquid cylinder by an O-ring.

[0023] As a further improvement of the present invention, a locking sleeve is screwed onto the lower end of the cylinder sleeve of the lower liquid cylinder, and a setting ring is screwed onto the lower end of the locking sleeve. A shear ring is screwed onto the middle external thread section of the lower setting ring connector. The outer edge of the shear ring abuts against the inner edge of the lower port of the locking sleeve, and the outer edge of the lower port of the locking sleeve abuts against the inner step of the setting ring. The middle section of the setting ring is fixed to the shear ring by a setting shear pin.

[0024] As a further improvement of the present invention, a cap is screwed onto the bottom of the middle external thread section of the lower setter joint, and the upper port of the cap is fitted onto the lower outer periphery of the shear ring.

[0025] As a further improvement of the present invention, a first reduced diameter section and a second reduced diameter section of the lower joint are sequentially provided below the upper sealing section of the lower joint. A locking ring and a backstop ring are fitted on the outer periphery of the second reduced diameter section of the lower joint. The upper end of the locking ring abuts against the step below the first reduced diameter section of the lower joint, and the backstop ring is located below the locking ring and is fixed to the outer periphery of the lower joint of the lower joint by a release shear pin.

[0026] As a further improvement of the present invention, the outer periphery of the locking ring is provided with an external ratchet, and the inner wall of the locking sleeve is provided with an internal ratchet. When the rubber sleeve is set, the internal ratchet of the locking sleeve and the external ratchet of the locking ring engage in one direction.

[0027] As a further improvement of the present invention, the upper end of the top rubber tube abuts against the lower end of the backwash seat, the inner wall of the backwash seat is sealed to the upper outer periphery of the outer central tube by an O-ring, the outer periphery of the backwash seat is screwed to the lower end of the upper backwash sleeve, and the upper port of the upper backwash sleeve is screwed to the male threaded outer periphery of the upper connector of the seat seal.

[0028] As a further improvement of the present invention, the lower end of the bottom rubber sleeve abuts against the top of the lower backwash sleeve, the upper port of the lower backwash sleeve is screwed to the lower end of the outer central tube, and the lower port of the lower backwash sleeve is screwed to the upper outer periphery of the upper liquid cylinder.

[0029] As a further improvement of the present invention, the lower backwash sleeve has a plurality of backwash outlet holes evenly distributed around its central circumference, and the upper backwash sleeve has a plurality of backwash inlet holes evenly distributed around its central circumference. The backwash inlet holes, the annular channel between the outer central tube and the upper central tube, and the backwash inlet holes constitute the backwash channel after the set seal.

[0030] As a further improvement of the present invention, the inner cavity of the upper backwash sleeve is provided with a backwash piston, the top of the backwash piston is located below the upper joint of the seat seal, and the outer wall of the backwash piston abuts against the inner wall of the upper backwash sleeve; the outer wall of the upper sealing section of the backwash piston and the inner wall of the upper backwash sleeve are mutually sealed, and the inner wall of the upper sealing section of the backwash piston abuts against the outer wall of the upper central tube and is mutually sealed.

[0031] As a further improvement of the present invention, a first expansion section of the backwash piston is provided below the upper sealing section of the backwash piston, and a sealing ring for setting is embedded in the inner wall of the first expansion section of the backwash piston; when the rubber sleeve sets, the upper outer periphery of the outer central tube is sealed with the sealing ring for setting.

[0032] As a further improvement of the present invention, a second expansion section of the backwash piston is provided below the first expansion section of the backwash piston. A pressure ring is screwed into the internal thread of the second expansion section of the backwash piston. The upper part of the pressure ring is sealed to the backwash piston through an O-ring. A sealing ring is embedded on the lower step of the pressure ring to form a seal with the lower end of the backwash piston.

[0033] As a further improvement of the present invention, the lower ends of the pressure ring and the sealing ring are provided with an outer conical surface, and the upper port of the backwash seat is provided with an inner conical surface; when the rubber tube achieves setting and sealing, the inner conical surface of the backwash seat and the outer conical surface of the sealing ring fit together and seal.

[0034] As a further improvement of the present invention, a lower release connector is screwed into the upper port of the upper seat seal connector, and an upper release connector is provided above the lower release connector. A plurality of claw springs are evenly provided on the lower circumference of the upper release connector, and the lower end of each claw spring protrudes outward and is embedded in the inner wall groove of the lower release connector.

[0035] As a further improvement of the present invention, the inner cavity of the upper connector of the dropper is provided with a sliding sleeve, the upper end of the sliding sleeve is provided with a flared mouth for the steel ball to be seated, and an O-ring is embedded in the upper outer periphery of the sliding sleeve to seal the inner wall of the upper connector of the dropper. The middle section of the sliding sleeve is provided with a reduced diameter section, and the lower part of the sliding sleeve is inserted into the inner cavity of the lower connector of the dropper and fixed by a dropper scissor pin.

[0036] Another objective of this invention is to provide a method for operating a composite quick-drilling water injection packer, which can overcome the problem of being unable to lift the packer when the water injection string fails, facilitate the removal of scale and retrieval of the packer, avoid major repairs, save operating time, and reduce costs.

[0037] To solve the above technical problems, the operating method of the composite rapid drilling water injection packer of the present invention includes the following steps in sequence:

[0038] S1, Setting: Lower the tool to the setting position, pressurize the tubing, the setting ring cuts the setting shear pin, and the pressure fluid pushes the lower and upper cylinders, along with the outer center tube, locking sleeve, and setting ring, upward together, compressing the rubber sleeve to set it, while the locking sleeve locks the locking ring.

[0039] S2. Backwash: Pressurize the casing annulus. The pressurized fluid enters the inner cavity of the upper backwash casing through the backwash inlet hole, descends along the annular space between the upper central tube and the outer central tube, reaches the inner cavity of the lower backwash casing, flows out from the backwash outlet hole, pushes open the check valve at the bottom of the tubing string, and returns to the wellhead along the central channel of the tubing string, washing away the dirt above the rubber sleeve.

[0040] S3. Unsealing: Lift the tubing column, which will move the upper central tube, lower central tube and lower sealing joint upwards, cut the unsealing shear pin, the anti-reverse ring will fall off, the locking ring and locking sleeve will disengage, and the rubber sleeve will spring back.

[0041] As an improvement of the present invention, when the setting seal is achieved in step S1, the upper end of the outer central tube is inserted into the lower inner cavity of the backwash piston and they are sealed to each other; at this time, the flared mouth at the upper end of the backwash seat is sealed with the sealing ring, and the backwash channel is closed.

[0042] As a further improvement of the present invention, if the dirt on the top of the glue tube is too much and too dense, making it impossible to unseal, then the following steps are performed:

[0043] S4. Release: Drop the steel ball, which lands on the upper end of the sliding sleeve to set and pressurize. Pressurize the wellhead, cut the release shear pin, and the sliding sleeve moves downward. The claw spring at the lower end of the release upper connector loses its support and disengages from the release lower connector. Then remove the upper tubing string and the release upper connector.

[0044] S5, Milling: The lower milling head removes the tapered outer shoulder of the upper joint of the set seal and the upper backwash sleeve made of composite material. The rubber sleeve springs back to complete the unsealing, and then the milled tube column is taken out.

[0045] S6. Retrieval: Use a male cone retrieval tool or a sleeve retrieval tool to retrieve the tool string left downhole.

[0046] Compared with the prior art, the present invention has achieved the following beneficial effects: 1. After the rubber sleeve is set, a backwashing well circulation can be established to flush away the dirt deposited on the rubber sleeve through backwashing;

[0047] 2. A hydraulic ball-dropping and release mechanism is designed on the upper part of the water injection packer. If it still cannot be lifted after backwashing, the hydraulic ball-dropping and release mechanism on the upper part of the composite fast drilling water injection packer can be released by dropping balls and pressurizing it. This allows the tubing above the packer to be pulled out of the wellhead for further processing.

[0048] 3. The upper backwash sleeve at the top of the rubber sleeve is made of large-diameter composite material. In the event of failure of the water injection tubing and inability to unseal, no major overhaul is required. The upper composite material and scale on the packer can be milled off with a milling tool, and the packer will unseal itself. Then, the retrieval tool can be used to retrieve the packer and the lower tubing, which greatly shortens the operation time and reduces production costs.

[0049] 4. The present invention addresses downhole faults in a clear and hierarchical manner. First, a relatively simple backwashing circulation is adopted, which can solve a considerable number of wells that cannot be pulled up. For complex wells that cannot be solved by backwashing, the method of letting go and milling is adopted to solve the problem, thus completely avoiding major workovers caused by such faults, saving time, labor and operating costs, and improving the oil well production rate. Attached Figure Description

[0050] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The drawings are provided for reference and illustration only and are not intended to limit the present invention.

[0051] Figure 1 This is a schematic diagram of the composite rapid drilling water injection packer of the present invention;

[0052] In the diagram: 1. Drop-off upper connector; 1a. Claw spring; 2. Steel ball; 3. Sliding sleeve; 4. Drop-off lower connector; 5. Drop-off shear pin; 6. Sliding sleeve sealing ring; 7. Setting seal upper connector; 8. Upper backwash sleeve; 8a. Backwash inlet port; 9. Upper central tube; 10. Backwash piston; 10a. Separator setting seal ring; 11. Pressure ring; 12. Sealing ring; 13. Backwash seat; 14. Outer central tube; 15. 16. Glue sleeve; 17. Lower backwash sleeve; 17a. Backwash outlet; 18. Upper liquid cylinder; 18a. Upper hydraulic chamber; 19. Lower center tube; 20. Lower liquid cylinder; 20a. Lower hydraulic chamber; 21. Lower setting joint; 22. Locking ring; 23. Anti-reverse ring; 24. Unsealing shear pin; 25. Locking sleeve; 26. Setting ring; 27. Setting shear pin; 28. Shearing ring; 29. ​​Connecting cap. Detailed Implementation

[0053] In the following description of the present invention, the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not mean that the device must have a specific orientation.

[0054] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific illustrations.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention.

[0056] like Figure 1 As shown, the composite quick-drilling water-filled packer of the present invention includes a release mechanism, a backwashing mechanism, a setting mechanism, and a setting drive mechanism. The release mechanism includes a release upper connector 1, a sliding sleeve 3, a release lower connector 4, and a release shear pin 5. The backwashing mechanism includes a backwash seat 13, a backwash piston 10, and an upper backwash sleeve 8. The setting mechanism includes an outer central tube 14, a rubber sleeve 15, and a spacer ring 16. The setting drive mechanism includes an upper liquid cylinder 18 and a lower liquid cylinder 20.

[0057] The claw spring 1a at the lower end of the upper dropper connector 1 is inserted into the cavity of the lower dropper connector 4; the sliding sleeve 3 is inserted into the cavity of the upper dropper connector 1 and forms a seal with the upper dropper connector 1 and the lower dropper connector 4 through the sliding sleeve sealing ring 6; the dropper scissor nail 5 is screwed into the screw hole of the lower dropper connector 4 to position the sliding sleeve 3; the male thread at the lower end of the lower dropper connector 4 is screwed into the upper port of the seat seal upper connector 7.

[0058] The lower end of the upper setter joint 7 is threaded to the upper end of the upper center tube 9; the backwash piston 10 is sleeved on the outer periphery of the upper center tube 9 and located in the inner cavity of the upper backwash sleeve 8, the top of the backwash piston 10 is located below the upper setter joint 7, and the outer wall of the backwash piston 10 abuts against the inner wall of the upper backwash sleeve 8.

[0059] The O-ring embedded in the inner wall of the upper end of the backwash piston 10 forms a seal with the outer wall of the upper central tube 9, and the O-ring embedded in the outer wall of the upper end of the backwash piston 10 forms a seal with the inner wall of the upper backwash sleeve 8. The upper port of the upper backwash sleeve 8 is screwed onto the outer circumference of the upper setter 7 via a female thread. Two O-rings are embedded in the lower outer circumference of the upper setter 7 to form a seal with the upper inner wall of the upper backwash sleeve 8. Multiple backwash inlet holes 8a are evenly distributed around the middle circumference of the upper backwash sleeve 8.

[0060] The upper backwash sleeve 8 is made of an easy-to-drill composite material, which is easy to mill while ensuring strength. The tapered outer shoulder of the upper setter 7 covers the top of the upper backwash sleeve 8, protecting the upper port of the upper backwash sleeve 8.

[0061] The outer diameter of the upper backwash sleeve 8 is equal to the outer diameter of the sleeve 15 in the non-setting state. The outer diameter of the tapered outer shoulder of the setting upper connector 7 is equal to the outer diameter of the upper backwash sleeve 8, and the diameter of the rest of the setting upper connector 7 is smaller than the diameter of the tapered outer shoulder. The outer diameters of the upper drop connector 1 and the lower drop connector 4 are equal to the outer diameter of the upper port of the setting upper connector 7, and are also smaller than the outer diameter of the tapered outer shoulder. This design facilitates milling of the tapered outer shoulder and the upper backwash sleeve 8 when unsealing is not possible. Furthermore, milling does not affect the strength of the setting upper connector 7, ensuring the strength and safety of the tubing string.

[0062] Below the upper sealing section of the backwash piston 10, there is a first expansion section of the backwash piston, and the inner wall of the first expansion section of the backwash piston is fitted with a packer setting seal ring 10a; when the rubber sleeve 15 achieves setting, the upper outer periphery of the outer center tube 14 is sealed with the packer setting seal ring 10a.

[0063] Below the first expansion section of the backwash piston is a second expansion section of the backwash piston. A pressure ring 11 is screwed into the internal thread of the second expansion section of the backwash piston. The pressure ring 11 is sleeved on the outer circumference of the upper central tube 9. A sealing ring 12 is embedded on the lower step of the pressure ring 11 to form a seal with the lower end of the backwash piston 10.

[0064] The lower ends of the pressure ring 11 and the sealing ring 12 are both provided with an outer conical surface, and the upper port of the backwash seat 13 is provided with an inner conical surface; when the rubber sleeve 15 achieves setting and sealing, the inner conical surface of the backwash seat 13 and the outer conical surface of the sealing ring 12 fit together and seal.

[0065] The outer periphery of the backwash seat 13 is screwed to the lower port of the upper backwash sleeve 8 via threads, and the inner wall of the backwash seat 13 is sealed to the outer central tube 14 via an O-ring.

[0066] The rubber sleeve 15 and the spacer ring 16 are fitted onto the outer center tube 14. The upper end of the top rubber sleeve 15 abuts against the lower end of the backwash seat 13, and the lower end of the bottom rubber sleeve 15 abuts against the top of the lower backwash sleeve 17.

[0067] The lower backwash sleeve 17 is screwed onto the lower outer periphery of the outer central tube 14. The upper inner wall of the lower backwash sleeve 17 is sealed to the outer wall of the outer central tube 14 through an O-ring. Multiple backwash outlet holes 17a are evenly distributed in the middle circumference of the lower backwash sleeve 17.

[0068] The upper liquid cylinder 18 is fitted onto the lower outer periphery of the upper central tube 9. The upper outer periphery of the upper liquid cylinder 18 is threaded into the lower port of the lower backwash sleeve 17. An O-ring is embedded in the inner wall of the upper liquid cylinder 18 to form a seal with the outer wall of the upper central tube 9. The inner periphery of the upper liquid cylinder 18, together with the upper central tube 9 and the lower central tube 19, forms an upper hydraulic cavity 18a. The lower circumference of the upper central tube 9 is provided with an upper injection hole that communicates with the upper hydraulic cavity 18a.

[0069] The upper end of the lower central tube 19 is screwed to the lower end of the upper central tube 9 by a thread. The upper end of the lower central tube 19 is located below the inner step of the upper liquid cylinder 18. An O-ring is embedded on the upper outer periphery of the lower central tube 19 to form a seal with the inner wall of the cylinder liner of the upper liquid cylinder 18.

[0070] The lower hydraulic cylinder 20 is fitted onto the lower outer periphery of the lower central tube 19. The upper end of the lower hydraulic cylinder 20 is threaded into the lower port of the upper hydraulic cylinder 18 sleeve. The inner periphery of the lower hydraulic cylinder 20, together with the lower central tube 19 and the lower seat joint 21, forms a lower hydraulic cavity 20a. The lower circumference of the lower central tube 19 is provided with a lower injection hole communicating with the lower hydraulic cavity 20a. The inner wall of the lower hydraulic cylinder 20 is sealed to the outer wall of the lower central tube 19 by an O-ring.

[0071] The upper end of the lower setting connector 21 is threaded to the lower end of the lower center tube 19. The top of the lower setting connector 21 abuts against the lower inner step of the lower liquid cylinder 20. An O-ring is embedded in the upper outer periphery of the lower setting connector 21 to form a seal with the inner wall of the cylinder liner of the lower liquid cylinder 20.

[0072] Locking ring 22 and anti-reverse ring 23 are fitted around the outer periphery of the lower setter joint 21. Locking ring 22 is located below the outer step of the lower setter joint 21. The upper and lower ends of locking ring 22 are vertically staggered with slots to give locking ring 22 a certain degree of elasticity. Anti-reverse ring 23 is located below locking ring 22, and the release pin 24 fixes anti-reverse ring 23 to the lower setter joint 21.

[0073] The upper end of the anti-reverse ring 23 is provided with an outer chamfer, and the lower end of the locking ring 22 is provided with an inner chamfer. The inner chamfer of the locking ring matches the outer chamfer of the anti-reverse ring, so that the locking ring 22 remains in an open state.

[0074] The upper part of the locking sleeve 25 is screwed into the lower port of the lower liquid cylinder 20 by male thread, and the lower end of the lower liquid cylinder 20 abuts against the upper part of the outer boss of the locking sleeve 25; the upper port of the sealing ring 26 is screwed into the lower outer periphery of the locking sleeve 25 by male thread, and the upper end of the sealing ring 26 abuts against the lower part of the outer boss of the locking sleeve 25.

[0075] The outer periphery of the locking ring 22 is provided with external ratchet teeth, and the inner wall of the locking sleeve 25 is provided with internal ratchet teeth. When the rubber sleeve 15 is set, the internal ratchet teeth of the locking sleeve 25 engage with the external ratchet teeth of the locking ring 22 in one direction.

[0076] The shear ring 28 is threaded onto the lower outer periphery of the lower setter joint 21 and is located in the inner cavity of the setter ring 26. The top of the shear ring 28 abuts against the lower part of the locking sleeve 25. The setter shear pin 27 is screwed into the threaded hole of the setter ring 26, and its inner end positions the shear ring 28.

[0077] The internal thread of the cap 29 is screwed onto the lower part of the external thread section of the set seal lower connector 21, and the upper part of the cap 29 is fitted onto the lower outer circumference of the shear ring 28.

[0078] Below the upper sealing section of the lower sealing joint 21, there are sequentially arranged a first reduced diameter section and a second reduced diameter section of the lower joint. The outer periphery of the second reduced diameter section of the lower joint is fitted with a locking ring 22 and a backstop ring 23. The upper end of the locking ring 22 abuts against the step below the first reduced diameter section of the lower joint, and the backstop ring 23 is located below the locking ring 22 and is fixed to the outer periphery of the lower sealing joint 21 by a release shear pin 24.

[0079] The operating steps for the composite rapid drilling type water injection packer are as follows:

[0080] S1. Setting: Lower the tool to the setting position, pressurize the tubing string, and pressurized fluid enters the lower hydraulic chamber 20a between the lower cylinder 20 and the lower setting connector 21 through the lower injection hole of the lower central tube 19, and enters the upper hydraulic chamber 18a between the upper cylinder 18 and the lower central tube 19 through the upper injection hole of the upper central tube 9. The setting ring 26 cuts the setting shear pin 27, and the pressurized fluid pushes the lower cylinder 20 and the upper cylinder 18, along with the outer central tube 14, the locking sleeve 25, and the setting ring 26, upward together, compressing the rubber sleeve 15 and causing it to expand and set on the inner wall of the wellbore. At the same time, the locking sleeve 25 locks the locking ring 22 to achieve one-way locking and prevent the rubber sleeve 15 from loosening.

[0081] The upper end of the outer center tube 14 is inserted into the lower inner cavity of the backwash piston 10 and is sealed with the O-ring on the inner wall of the lower expanded section of the backwash piston 10; at this time, the flared mouth at the upper end of the backwash seat 13 is sealed with the sealing ring 12, closing the backwash channel.

[0082] S2. Backwashing: The backwash inlet 8a on the upper backwash sleeve 8, the annular space between the upper central tube 9 and the outer central tube 14, and the backwash outlet 17a on the lower backwash sleeve 17 form a backwashing channel for backwashing. During backwashing, the casing annulus is pressurized. When the pressurized fluid reaches above the sealing section of the rubber sleeve 15, it enters the inner cavity of the upper backwash sleeve 8 through the backwash inlet 8a, pushing the backwash piston 10 to the top. The pressurized fluid flows down along the annular space between the upper central tube 9 and the outer central tube 14, passes over the sealing position of the rubber sleeve 15, reaches the inner cavity of the lower backwash sleeve 17, and then flows out through the backwash outlet 17a into the annulus below the rubber sleeve 15 and flows downward. It pushes open the check valve at the bottom of the tubing string and returns to the wellhead along the central channel of the tubing string. During the backwashing flow, the dirt that falls above the rubber sleeve 15 is washed away.

[0083] S3. Unsealing: Lift the tubing column, which will drive the upper central tube 9, the lower central tube 19 and the lower seat joint 21 upward. When the lower seat joint 21 cuts the unsealing shear pin 24, the anti-reverse ring 23 falls off, the inner side of the locking ring 22 loses support and disengages from the locking sleeve 25, and the rubber sleeve 15 rebounds, completing the unsealing.

[0084] S4. Release: If there is too much and dense dirt on the top of the rubber sleeve 15, the unsealing force is too great, making it impossible to unseal; then steel ball 2 is dropped from the wellhead. Steel ball 2 falls to the upper port of the sliding sleeve 3 to set and pressurize. The wellhead is pressurized, the release shear pin 5 is cut, the sliding sleeve 3 moves down, and the reduced diameter section in the middle of the outer periphery of the sliding sleeve 3 slides down to be opposite to the claw spring 1a at the lower end of the release upper connector 1. The inner side of the claw spring 1a loses support, and the outer circumference protrusion disengages from the inner ring groove of the release lower connector 4, completing the release. After the release, the upper tubing string and the release upper connector 1 are taken out.

[0085] S5, Milling: The lower milling head removes the tapered outer shoulder of the upper joint 7 of the seat seal and the upper backwash sleeve 8 made of composite material. The backwash seat 13 loses support, the rubber sleeve 15 springs upward to complete the unsealing, and then the milling column is taken out.

[0086] S6. Retrieval: Use a male cone retrieval tool or a sleeve retrieval tool to retrieve the tool string left downhole.

[0087] The above description is merely a preferred embodiment of the present invention, showing and describing the basic principles, main features, and advantages of the present invention. It is not intended to limit the scope of patent protection of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. In addition to the above embodiments, the present invention may have other implementations without departing from the spirit and scope of the invention. Various changes and modifications to the present invention are possible, and all technical solutions formed by equivalent substitutions or equivalent transformations fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents. Technical features not described in the present invention can be implemented by or using existing technology, and will not be elaborated here.

Claims

1. A composite rapid drilling type water injection packer, characterized in that, include: The upper connector (7) is seated, and the lower end is provided with male and female threads; The upper center tube (9) is screwed into the female thread of the upper joint (7) of the seat seal; The lower center tube (19) is screwed to the lower end of the upper center tube (9); The lower connector (21) is set, and its upper end is screwed to the lower end of the lower central tube (19); The sealing mechanism is located on the outer periphery of the upper central tube (9) and includes an outer central tube (14) fitted on the outer periphery of the upper central tube (9). An annular channel is left between the outer central tube (14) and the upper central tube (9). Multiple rubber tubes (15) are fitted on the outer periphery of the outer central tube (14). A setting and sealing drive mechanism is located below the setting and sealing mechanism; The upper end of the top rubber tube (15) abuts against the lower end of the backwash seat (13). The inner wall of the backwash seat (13) is sealed to the upper outer periphery of the outer center tube (14) by an O-ring. The outer periphery of the backwash seat (13) is screwed to the lower end of the upper backwash sleeve (8). The upper port of the upper backwash sleeve (8) is screwed to the male threaded outer periphery of the upper connector (7) of the seat seal. The upper backwash sleeve (8) has multiple backwash inlet holes (8a) evenly distributed around its central circumference. The inner cavity of the upper backwash sleeve (8) is provided with a backwash piston (10). The backwash piston (10) is located above the backwash inlet hole (8a) and its top abuts against the lower end face of the upper setter (7). It also includes a sealing assembly disposed at the lower part of the backwash piston (10); when the rubber sleeve (15) is seated, the upper end of the outer central tube (14) is inserted into the lower inner cavity of the backwash piston (10) to form a first seal, and at the same time the backwash seat (13) and the sealing assembly form a second seal, so that the backwash inlet hole (8a) and the annular channel remain closed during water injection.

2. The composite rapid drilling type water injection packer according to claim 1, characterized in that, A spacer ring (16) is provided between adjacent rubber tubes (15).

3. The composite rapid drilling type water injection packer according to claim 2, characterized in that: The setting drive mechanism includes: The upper hydraulic cylinder (18) is fitted on the lower outer periphery of the upper central tube (9), and its inner periphery, together with the upper central tube (9) and the lower central tube (19), forms the upper hydraulic cavity (18a). The lower hydraulic cylinder (20) is fitted on the lower outer periphery of the lower central tube (19), and its inner periphery, together with the lower central tube (19) and the lower seat joint (21), forms the lower hydraulic cavity (20a). The lower circumference of the upper central tube (9) is provided with an upper injection hole that communicates with the upper hydraulic chamber (18a), and the lower circumference of the lower central tube (19) is provided with a lower injection hole that communicates with the lower hydraulic chamber (20a).

4. The composite rapid drilling type water injection packer according to claim 3, characterized in that: The upper end of the lower central tube (19) is located below the inner step of the upper liquid cylinder (18), and the upper outer periphery of the lower central tube (19) is sealed to the cylinder liner of the upper liquid cylinder (18) by an O-ring.

5. The composite rapid drilling type water injection packer according to claim 3, characterized in that: The top of the lower setting joint (21) abuts against the inner step of the lower liquid cylinder (20), and the upper outer periphery of the lower setting joint (21) is sealed to the cylinder liner of the lower liquid cylinder (20) by an O-ring.

6. The composite rapid drilling type water injection packer according to claim 3, characterized in that: The lower end of the cylinder sleeve of the lower liquid cylinder (20) is screwed with a locking sleeve (25), and the lower end of the locking sleeve (25) is screwed with a setting ring (26). The middle external thread section of the setting lower connector (21) is screwed with a shear ring (28). The outer edge of the shear ring (28) abuts against the inner edge of the lower port of the locking sleeve (25), and the outer edge of the lower port of the locking sleeve (25) abuts against the inner step of the setting ring (26). The middle section of the setting ring (26) is fixed on the shear ring (28) by a setting shear pin (27).

7. The composite rapid drilling type water injection packer according to claim 6, characterized in that: The bottom of the middle external thread section of the set seal lower connector (21) is screwed with a cap (29), and the upper end of the cap (29) is fitted onto the lower outer periphery of the shear ring (28).

8. The composite rapid drilling type water injection packer according to claim 6, characterized in that: The lower sealing section of the lower sealing joint (21) is provided with a first reduced diameter section and a second reduced diameter section in sequence below the upper sealing section. The outer periphery of the second reduced diameter section is fitted with a locking ring (22) and a backstop ring (23). The upper end of the locking ring (22) abuts against the step below the first reduced diameter section of the lower sealing joint. The backstop ring (23) is located below the locking ring (22) and is fixed to the outer periphery of the lower sealing joint (21) by a release shear pin (24).

9. The composite rapid drilling type water injection packer according to claim 8, characterized in that: The outer periphery of the locking ring (22) is provided with external ratchet teeth, and the inner wall of the locking sleeve (25) is provided with internal ratchet teeth. When the rubber sleeve (15) is set, the internal ratchet teeth of the locking sleeve (25) and the external ratchet teeth of the locking ring (22) engage in one direction.

10. The composite rapid drilling type water injection packer according to claim 4, characterized in that: The lower end of the bottom rubber sleeve (15) abuts against the top of the lower backwash sleeve (17), the upper port of the lower backwash sleeve (17) is screwed to the lower end of the outer central tube (14), and the lower port of the lower backwash sleeve (17) is screwed to the upper outer periphery of the upper liquid cylinder (18).

11. The composite rapid drilling type water injection packer according to claim 10, characterized in that: The lower backwash sleeve (17) has multiple backwash outlet holes (17a) evenly distributed around its central circumference. The backwash inlet hole (8a), the annular channel between the outer central tube (14) and the upper central tube (9), and the backwash inlet hole (8a) constitute the backwash channel after the set seal.

12. The composite rapid drilling type water injection packer according to claim 1, characterized in that: The outer wall of the backwash piston (10) abuts against the inner wall of the upper backwash sleeve (8); the outer wall of the upper sealing section of the backwash piston (10) and the inner wall of the upper backwash sleeve (8) are mutually sealed, and the inner wall of the upper sealing section of the backwash piston (10) abuts against the outer wall of the upper central tube (9) and is mutually sealed.

13. The composite rapid drilling type water injection packer according to claim 12, characterized in that: The backwash piston (10) has a first expansion section below the upper sealing section, and the inner wall of the first expansion section is fitted with a sealing ring (10a). When the rubber sleeve (15) is set, the outer periphery of the upper end of the outer central tube (14) is sealed with the sealing ring (10a) to form the first seal.

14. The composite rapid drilling type water injection packer according to claim 13, characterized in that: Below the first expansion section of the backwash piston is a second expansion section of the backwash piston. A pressure ring (11) is screwed into the internal thread of the second expansion section of the backwash piston. The upper part of the pressure ring (11) is sealed to the backwash piston (10) by an O-ring. A sealing ring (12) is embedded on the lower step of the pressure ring (11) to form a seal with the lower end of the backwash piston (10). The sealing ring (12) and the pressure ring (11) constitute the sealing assembly.

15. The composite rapid drilling type water injection packer according to claim 14, characterized in that: The lower ends of the pressure ring (11) and the sealing ring (12) are provided with an outer conical surface, and the upper port of the backwash seat (13) is provided with an inner conical surface; when the rubber tube (15) achieves setting and sealing, the inner conical surface of the backwash seat (13) and the outer conical surface of the sealing ring (12) fit together and seal each other, forming the second seal.

16. The composite rapid drilling type water injection packer according to claim 1 or 15, characterized in that: The upper port of the seat seal upper connector (7) is screwed with a dropper lower connector (4). Above the dropper lower connector (4) is a dropper upper connector (1). The lower circumference of the dropper upper connector (1) is evenly provided with multiple claw springs (1a). The lower end of each claw spring (1a) protrudes outward and is embedded in the groove of the inner wall of the dropper lower connector (4).

17. The composite rapid drilling type water injection packer according to claim 16, characterized in that: The inner cavity of the drop-hand connector (1) is provided with a sliding sleeve (3). The upper end of the sliding sleeve (3) is provided with a flared mouth for the steel ball (2) to sit on. An O-ring is embedded in the upper outer periphery of the sliding sleeve (3) to seal the inner wall of the drop-hand connector (1). The middle section of the sliding sleeve (3) is provided with a reduced diameter section. The lower part of the sliding sleeve (3) is inserted into the inner cavity of the drop-hand connector (4) and fixed by a drop-hand scissor nail (5).

18. A method for operating the composite rapid drilling type water injection packer as described in claim 17, characterized in that, The steps are as follows: S1, Setting: Lower the tool to the setting position, pressurize the tubing, and the setting ring (26) cuts the setting shear pin (27). The pressure liquid pushes the lower cylinder (20) and the upper cylinder (18) together with the outer central tube (14), the locking sleeve (25), and the setting ring (26) to move upward, compressing the rubber tube (15) to set it. At the same time, the locking sleeve (25) locks the locking ring (22). While setting, the upper end of the outer central tube (14) is inserted into the lower inner cavity of the backwash piston (10) to form a first seal. The backwash seat (13) and the sealing ring (12) fit together to form a second seal, so that the backwash inlet hole (8a) and the annular channel remain closed during water injection. S2, backwash: Pressurize the casing annulus, and pressurized fluid enters the inner cavity of the upper backwash sleeve (8) through the backwash inlet hole (8a), descends along the annular space between the upper central tube (9) and the outer central tube (14), reaches the inner cavity of the lower backwash sleeve (17), flows out through the backwash outlet hole (17a), pushes open the single-flow valve at the bottom of the tubing string, and returns to the wellhead along the central channel of the tubing string, washing away the dirt above the rubber sleeve (15); S3, Unsealing: Lift the tubing column, which will drive the upper central tube (9), lower central tube (19) and the lower sealing connector (21) upward, cut off the unsealing shear pin (24), the anti-reverse ring (23) falls off, the locking ring (22) and the locking sleeve (25) disengage, and the rubber tube (15) rebounds.

19. The method of operating the composite rapid drilling water injection packer according to claim 18, characterized in that: When the setting seal is achieved in step S1, the upper end of the outer center tube (14) is inserted into the lower inner cavity of the backwash piston (10) and they are sealed to each other; at this time, the flared mouth at the upper end of the backwash seat (13) and the sealing ring (12) are sealed to close the backwash channel.

20. The method of operating the composite rapid drilling water injection packer according to claim 18, characterized in that: If the dirt on the top of the rubber tube (15) is too much and too dense, making it impossible to unseal, then continue with the following steps: S4, Drop: Insert steel ball (2), steel ball (2) lands on the upper end of the sliding sleeve (3) to seal and pressurize, pressurize the wellhead, cut the drop shear pin (5), the sliding sleeve (3) moves downward, the claw spring (1a) at the lower end of the drop upper connector (1) loses support and disengages from the drop lower connector (4); then take out the upper tubing string and the drop upper connector (1); S5, Milling: The lower milling head mills the tapered outer shoulder of the upper joint (7) of the seat seal and the upper backwash sleeve (8) made of composite material. The rubber tube (15) springs back to complete the unsealing, and then the milling column is taken out. S6. Retrieval: Use a male cone retrieval tool or a sleeve retrieval tool to retrieve the tool string left downhole.

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