A downhole hydraulic backoff device

Abstract

The application discloses a downhole hydraulic back-off device, which comprises an outer cylinder assembly arranged vertically, an inner cylinder assembly coaxially arranged in the outer cylinder assembly, a back-off assembly coaxially connected to the bottom of the inner cylinder assembly and used for being connected with a stuck part, a hydraulic assembly used for controlling the inner cylinder assembly to move in the vertical direction, and a driving assembly used for controlling the back-off assembly to rotate. The application can realize smooth unjamming of a pipe string and has the advantages of compact structure, large output torque and wide application range.

Description

Technical Field

[0001] This invention belongs to the field of oil drilling and well workover technology, specifically relating to a downhole hydraulic reverse-clamping device. Background Technology

[0002] In recent years, production enhancement measures have been necessary during the development of oil and gas wells, especially in the later stages of extraction. However, during drilling and oil production, tubing often becomes stuck. When a stuck incident occurs, the handling is difficult, time-consuming, and costly, and in severe cases, it can even lead to the abandonment of the wellbore.

[0003] There are currently four common methods for dealing with stuck tubing: first, using a reverse-threading drill bit to reverse-thread the stuck part; second, using a cutting method to cut off the stuck part; third, using explosive release technology to release the thread through the impact of an explosion; and fourth, using a planetary gear mechanical reverse-threading tool.

[0004] However, in practical applications, the above-mentioned methods have significant limitations. For example, the production and transportation costs of reverse-threading drills are too high; traditional cutting methods are prone to damaging the tubing and are relatively cumbersome to operate; and the use of blasting methods can only ensure a good initial reverse-threading effect, which is detrimental to subsequent reverse-threading operations, and the impact force can damage other tools. Summary of the Invention

[0005] In order to solve all or some of the above problems, the purpose of this invention is to provide a downhole hydraulic untangling device that can realize the smooth untangling of the tubing string, and has the advantages of compact structure, large output torque and wide applicability.

[0006] This invention provides a downhole hydraulic reverse-locking device, comprising: The outer cylinder assembly is vertically positioned. The inner cylinder assembly is coaxially disposed within the outer cylinder assembly; The inverted assembly is coaxially connected to the bottom of the inner cylinder assembly and is used to connect with the locked component; A hydraulic assembly is used to control the movement of the inner cylinder assembly in the vertical direction; A drive assembly for controlling the rotation of the underpinning assembly.

[0007] Optionally, the outer cylinder assembly includes, from top to bottom, a connector assembly, a hydraulic outer cylinder, a hydraulic connector, a first short connector, a splined outer cylinder, a second short connector, a support sleeve, a third short connector, a lower outer shell, and a lower end cap. The inner cylinder assembly includes, from top to bottom, a hydraulic sealing end cap, an upper hydraulic central tube, a piston cylinder, a lower hydraulic central tube, and a lead screw cylinder; The inverted assembly includes a first transmission pipe, a second transmission pipe, a lower connector, a lower single-flow ball seat, and a retrieval cylinder, which are connected sequentially from top to bottom.

[0008] Optionally, the hydraulic assembly includes: The sliding sleeve is located inside the connector assembly and can be opened under external pressure. The sealing ball is used to form a sealing fit with the sealing surface inside the lower single-flow ball seat to seal the lower single-flow ball seat, so that the inner cylinder assembly can move vertically downward under external pressure. A reset mechanism is used to control the vertical upward movement of the inner cylinder assembly.

[0009] Optionally, the opening sleeve includes: A retaining sleeve is provided within the connector assembly; A flow channel annular groove is provided on the inner wall of the fixed sleeve; The first flow channel is a plurality of vertically arranged inside the fixed sleeve, and the top of the plurality of first flow channels is respectively connected to the flow channel annular groove; The sliding sleeve is connected to the fixed sleeve by a shear pin; A first through hole is provided on the sliding sleeve; A sealing ball is used to form a sealing fit with the sealing surface inside the sliding sleeve to seal the sliding sleeve; The shear pin can be sheared under external pressure, so that the sliding sleeve can move vertically downward and connect the first through hole with the flow channel annular groove.

[0010] Optionally, a limiting ring is provided at the lower end of the fixed sleeve. When the sliding sleeve moves downward and forms an abutment with the limiting ring, the first through hole is aligned with the flow channel annular groove.

[0011] Optionally, the reset mechanism includes: The upper spring sleeve is connected to the bottom of the piston cylinder; The lower spring sleeve is connected to the top of the hydraulic joint; The reset spring has one end connected to the upper spring sleeve and the other end connected to the lower spring sleeve.

[0012] Optionally, a hydraulic annular cavity is formed between the upper spring sleeve, the lower spring sleeve, and the lower hydraulic center tube, the reset spring is disposed in the hydraulic annular cavity, and the hydraulic annular cavity is filled with hydraulic oil; The hydraulic connector has a second flow channel inside, and the lower spring sleeve has a second through hole inside that connects the second flow channel and the hydraulic ring cavity. The hydraulic connector has a hydraulic interface that communicates with the second flow channel, and the hydraulic interface is used to connect with an external hydraulic pipeline.

[0013] Optionally, the drive assembly includes: The spline block is mounted on the lead screw cylinder and slides vertically with the spline outer cylinder. A nut sleeve is rotatably connected to the support sleeve. The nut sleeve is threaded onto the lead screw sleeve, and the thread helix angle of the threaded section at the lower end of the lead screw sleeve is greater than 70°, so that the nut sleeve can rotate when the lead screw sleeve moves vertically. A ratchet mechanism is used to restrict the second transmission tube from rotating synchronously when the first transmission tube rotates counterclockwise, and to keep the second transmission tube stationary when the first transmission tube rotates clockwise.

[0014] Optionally, the ratchet mechanism includes: The first ratchet grooves are multiple and are respectively disposed on the inner wall of the support sleeve, and the multiple first ratchet grooves are arranged sequentially along the circumference of the support sleeve; The first ratchet slider is slidably connected to the first transmission tube and can engage with any of the first ratchet slots; The first springs, in multiple quantities, are used to push the corresponding first ratchet sliders toward the support sleeve, so that the first ratchet sliders are engaged in the corresponding first ratchet slots; There are multiple second ratchet slots, which are respectively disposed on the inner wall of the lower outer shell. The multiple second ratchet slots are arranged sequentially along the circumference of the lower outer shell. The second ratchet slider is slidably connected to the second transmission tube and can engage with any of the second ratchet slots; There are multiple second springs, each used to push the corresponding second ratchet slider toward the lower outer casing, so that the second ratchet slider engages with the corresponding second ratchet slot.

[0015] Optionally, the connector assembly includes a hydraulic anchor, a top connector of a shear check valve, a bottom connector of a shear check valve, and an upper connector connected in sequence from top to bottom, and the upper connector is coaxially connected to the hydraulic outer cylinder.

[0016] As can be seen from the above technical solution, the downhole hydraulic reverse-clamping device provided by the present invention has the following advantages: This device uses hydraulic power to drive the inner cylinder assembly to move linearly. The lead screw of the inner cylinder assembly and the nut of the outer cylinder assembly can convert the linear motion into the rotational motion of the reverse assembly, so that the reverse assembly can smoothly perform reverse unblocking operations on stuck objects. It has the advantages of compact overall structure, large output torque, and suitability for high-angle wells and horizontal wells.

[0017] Other features and advantages of the present invention will be set forth in the following description. Attached Figure Description

[0018] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the technical solutions of the present invention, and do not constitute a limitation on the technical solutions of the present invention.

[0019] Figure 1 This is a cross-sectional view of an embodiment of the present invention; Figure 2 This is a cross-sectional view of the outer cylinder assembly in an embodiment of the present invention; Figure 3 This is a cross-sectional view of the inner cylinder assembly in an embodiment of the present invention; Figure 4 This is a cross-sectional view of the undercut assembly in an embodiment of the present invention; Figure 5 This is a cross-sectional view of the connector assembly in an embodiment of the present invention; Figure 6 This is a cross-sectional view of an embodiment of the present invention, mainly showing the reset mechanism; Figure 7 This is a cross-sectional view of an embodiment of the present invention, mainly showing the drive mechanism; Figure 8 This is a cross-sectional view of an embodiment of the present invention, mainly showing the drive mechanism.

[0020] Explanation of reference numerals in the attached figures: 100. Outer cylinder assembly; 1. Connector assembly; 101. Hydraulic anchor; 102. Top connector of shear check valve; 103. Bottom connector of shear check valve; 104. Upper connector; 105. Third end cap; 2. Hydraulic outer cylinder; 3. Hydraulic connector; 4. First short connector; 5. Splined outer cylinder; 6. Second short connector; 7. Support sleeve; 8. Third short connector; 9. Lower outer shell; 10. Lower end cap; 11. First end cap; 12. Second end cap; 200. Inner cylinder assembly; 21. Hydraulic sealing end cap; 22. Upper hydraulic center tube; 23. Piston cylinder; 24. Lower hydraulic center tube; 25. Lead screw cylinder; 26. Fourth end cap; 27. Fifth end cap; 300. Inverted assembly; 31. First transmission pipe; 32. Second transmission pipe; 33. Lower connector; 34. Lower single-flow ball seat; 35. Retrieval cylinder; 400. Hydraulic assembly; 41. Opening sleeve; 411. Fixed sleeve; 412. Flow channel annular groove; 413. First flow channel; 414. Sliding sleeve; 415. Sealing ball; 416. Shear pin; 417. First through hole; 418. Limiting ring; 42. Blocking ball; 43. Reset mechanism; 431. Upper spring sleeve; 432. Lower spring sleeve; 433. Reset spring; 44. Hydraulic annular cavity; 45. Second flow channel; 46. Second through hole; 47. Hydraulic interface; 500. Drive assembly; 51. Spline block; 52. Nut sleeve; 53. Ratchet mechanism; 531. First ratchet slot; 532. First ratchet slider; 533. First spring; 534. Second ratchet slot; 535. Second ratchet slider; 536. Second spring; 61. Sealing ring; 62. Straightening ring. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be arbitrarily combined with each other.

[0022] like Figures 1-8 The illustration shows an embodiment of the present invention, which discloses a downhole hydraulic buckling device, including an outer cylinder assembly 100, an inner cylinder assembly 200, a buckling assembly 300, a hydraulic assembly 400, and a drive assembly 500. The outer cylinder assembly 100 is vertically arranged, and the inner cylinder assembly 200 is coaxially arranged and movably placed inside the outer cylinder assembly 100. The buckling assembly 300 is coaxially connected to the bottom of the inner cylinder assembly 200 and is used to connect with the stuck component. The hydraulic assembly 400 is used to control the inner cylinder assembly 200 to drive the buckling assembly 300 to move in the vertical direction, and the drive assembly 500 is used to control the rotation of the buckling assembly 300 to realize the buckling and release of the stuck component.

[0023] In one embodiment, such as Figure 1 , Figure 2 As shown, the outer cylinder assembly 100 includes a connector assembly 1, a hydraulic outer cylinder 2, a hydraulic connector 3, a first short connector 4, a splined outer cylinder 5, a second short connector 6, a support sleeve 7, a third short connector 8, a lower outer casing 9, and a lower end cap 10 arranged coaxially from top to bottom. At the same time, a first end cap 11 is provided at the bottom of the hydraulic connector 3, and a second end cap 12 is provided at the bottom of the lower end cap 10.

[0024] In this embodiment, the connector assembly 1, hydraulic outer cylinder 2, hydraulic connector 3, first short connector 4, splined outer cylinder 5, second short connector 6, support sleeve 7, third short connector 8, lower outer shell 9, and lower end cap 10 are connected by reverse thread. The first end cap 11 is fixed to the bottom of the hydraulic connector 3 by bolts, and the second end cap 12 is fixed to the bottom of the lower end cap 10 by bolts.

[0025] In one embodiment, such as Figure 1 , Figure 2 As shown, the connector assembly 1 includes a hydraulic anchor 101, a shear check valve top connector 102, a shear check valve bottom connector 103, and an upper connector 104 arranged coaxially from top to bottom. At the same time, a third end cap 105 is provided at the bottom of the upper connector 104.

[0026] In this embodiment, the hydraulic anchor 101, the top connector 102 of the shear check valve, the bottom connector 103 of the shear check valve, and the upper connector 104 are respectively connected by reverse thread, and the third end cap 105 is fixed to the bottom of the upper connector 104 by bolts.

[0027] In one embodiment, such as Figure 1 , Figure 3 As shown, the inner cylinder assembly 200 includes a hydraulic sealing end cap 21, an upper hydraulic center tube 22, a piston cylinder 23, a lower hydraulic center tube 24, and a lead screw cylinder 25 arranged coaxially from top to bottom. At the same time, a fourth end cap 26 is provided on the top of the piston cylinder 23, and a fifth end cap 27 is provided on the bottom of the lead screw cylinder 25.

[0028] In this embodiment, the hydraulic sealing end cap 21, the upper hydraulic center tube 22, the piston cylinder 23, the lower hydraulic center tube 24, and the lead screw cylinder 25 are respectively connected by reverse thread. The fourth end cap 26 is fixed to the top of the piston cylinder 23 by bolts, and the fifth end cap is fixed to the bottom of the lead screw cylinder 25 by bolts.

[0029] In one embodiment, such as Figure 1 , Figure 4 As shown, the inverted assembly 300 includes a first transmission pipe 31, a second transmission pipe 32, a lower connector 33, a lower single-flow ball seat 34, and a retrieval cylinder 35 arranged coaxially from top to bottom. The top of the first transmission pipe 31 is inserted into the lead screw cylinder 25 and the bottom is inserted into the second transmission pipe 32. The second transmission pipe 32, the lower connector 33, the lower single-flow ball seat 34, and the retrieval cylinder 35 are connected by reverse threads, and the retrieval cylinder 35 is used to fit onto the stuck part.

[0030] In one embodiment, such as Figure 4 , Figure 5 , Figure 6 As shown, the hydraulic assembly 400 includes an opening sleeve 41, a sealing ball 42, and a reset mechanism 43. The opening sleeve 41 is disposed within the bottom connector 103 of the shear check valve and can be opened under external pressure. The sealing ball 42 can be dropped from the hydraulic anchor 101 and forms a sealing fit with the sealing surface within the lower check valve seat 34 to seal the lower check valve seat 34, thereby allowing the inner cylinder assembly 200 to move vertically downward under external pressure. The reset mechanism 43 is used to control the vertical upward movement of the inner cylinder assembly 200.

[0031] In one embodiment, such as Figure 5 As shown, the opening sleeve 41 includes a fixed sleeve 411 coaxially fixed inside the bottom connector 103 of the shear single flow valve. The inner wall of the fixed sleeve 411 is provided with a flow channel annular groove 412. A plurality of first flow channels 413 are vertically arranged inside the fixed sleeve 411, and the tops of the plurality of first flow channels 413 are respectively connected to the flow channel annular groove 412.

[0032] In one embodiment, such as Figure 5 As shown, the opening sliding sleeve 41 also includes a sliding sleeve 414 and a sealing ball 415. The sliding sleeve 414 is fixed inside the fixed sleeve 411 by a shear pin 416, and a first through hole 417 is provided on the sliding sleeve 414. After the hydraulic anchor 101 is disassembled, the sealing ball 415 can be dropped from the top connector 102 of the shear single-flow valve and form a sealing fit with the sealing surface inside the sliding sleeve 414 to seal the sliding sleeve 414. When external pressure is applied, the shear pin 416 can be sheared under the external pressure, so that the sliding sleeve 414 can move vertically downward and the first through hole 417 can communicate with the flow channel annular groove 412.

[0033] In one embodiment, such as Figure 5 As shown, the lower end of the fixed sleeve 411 is integrally formed with a limiting ring 418. When the sliding sleeve 414 moves downward and forms an abutment with the limiting ring 418, the first through hole 417 is aligned with the flow channel annular groove 412, thereby ensuring that the first through hole 417 and the flow channel annular groove 412 are smoothly connected.

[0034] In this embodiment, the outer diameter of the sealing ball 42 is larger than the outer diameter of the sealing ball 415, and the outer surfaces of the sealing ball 42 and the sealing ball 415 are rubber layers to ensure the sealing effect.

[0035] When the sealing ball 42 and sealing ball 415 are dropped, the external pressure equipment pressurizes the cylinder. Under pressure, the sliding sleeve 414 shears the shear pin 416, and then moves downward until it abuts against the limiting ring 418. At this time, the first through hole 417 connects with the flow channel annular groove 412, and the pressurizing liquid flows downward through the first through hole 417, the flow channel annular groove 412, and multiple first flow channels 413. Then, the pressurizing liquid is pressurized in the area between the sealing ball 42 and sealing ball 415. As the pressure equipment continues to pressurize, the inner cylinder assembly 200 drives the reverse buckle assembly 300 to move downward.

[0036] In one embodiment, such as Figure 6 As shown, the reset mechanism 43 includes an upper spring sleeve 431, a lower spring sleeve 432, and a reset spring 433. The upper spring sleeve 431 is connected to the bottom of the piston cylinder 23 by a reverse thread, and the lower spring sleeve 432 is connected to the top of the hydraulic connector 3 by a reverse thread. One end of the reset spring 433 is connected to the upper spring sleeve 431, and the other end is connected to the lower spring sleeve 432.

[0037] In one embodiment, such as Figure 6As shown, a hydraulic annular cavity 44 is formed between the upper spring sleeve 431, the lower spring sleeve 432, and the lower hydraulic center pipe 24. The return spring 433 is disposed within the hydraulic annular cavity 44, which is filled with hydraulic oil. Simultaneously, a second flow channel 45 is provided inside the hydraulic connector 3, and a second through hole 46 connecting the second flow channel 45 and the hydraulic annular cavity 44 is provided inside the lower spring sleeve 432. A hydraulic interface 47 communicating with the second flow channel 45 is provided on the hydraulic connector 3, and the hydraulic interface 47 is used for connection to an external hydraulic pipeline.

[0038] When the inner cylinder assembly 200 moves downward, the upper spring sleeve 431 moves downward synchronously. At this time, the return spring 433 gradually compresses, and the hydraulic oil in the hydraulic ring cavity 44 is discharged through the hydraulic interface 47. When the external pressurizing equipment stops pressurizing, the external hydraulic pipeline pressurizes, and the hydraulic oil enters the hydraulic ring cavity 44. Combined with the elastic force of the return spring 433, the upper spring sleeve 431 drives the inner cylinder assembly 200 to move upward.

[0039] In one embodiment, such as Figure 7 , Figure 8 As shown, the drive assembly 500 includes a spline block 51, a nut sleeve 52, and a ratchet mechanism 53. The spline block 51 is vertically fixed to the lead screw cylinder 25, and the spline block 51 and the spline outer cylinder 5 are vertically slidingly engaged to achieve guidance and anti-rotation. The top of the nut sleeve 52 is connected to the support sleeve 7 through a cylindrical roller thrust bearing, and the nut sleeve 52 is threaded onto the lead screw cylinder 25. Simultaneously, the thread helix angle of the threaded section at the lower end of the lead screw cylinder 25 is greater than 70°, so that the nut sleeve 52 can rotate when the lead screw cylinder 25 moves vertically. The ratchet mechanism 53 is used to restrict the second drive pipe 32 from rotating synchronously when the first drive pipe 31 rotates counterclockwise, and the second drive pipe 32 remains stationary when the first drive pipe 31 rotates clockwise.

[0040] In one embodiment, such as Figure 8 As shown, the ratchet mechanism 53 includes a plurality of first ratchet slots 531, which are respectively disposed on the inner wall of the support sleeve 7 and arranged sequentially along the circumference of the support sleeve 7. Meanwhile, a first ratchet slider 532 is slidably connected to the first transmission tube 31, and the first ratchet slider 532 can engage with any of the first ratchet slots 531.

[0041] In one embodiment, such as Figure 8 As shown, the first transmission tube 31 is provided with multiple spring slots, and a first spring 533 is fixedly connected in each spring slot. The first spring 533 is fixedly connected to the corresponding first ratchet slider 532. At the same time, the first spring 533 is used to push the corresponding first ratchet slider 532 toward the support sleeve 7 so that the first ratchet slider 532 is engaged in the corresponding first ratchet slot 531.

[0042] In one embodiment, such as Figure 8 As shown, the ratchet mechanism 53 also includes a plurality of second ratchet slots 534, which are respectively disposed on the inner wall of the lower outer casing 9 and arranged sequentially along the circumference of the lower outer casing 9. Meanwhile, a second ratchet slider 535 is slidably connected to the second transmission tube 32, and the second ratchet slider 535 can engage with any of the second ratchet slots 534.

[0043] In one embodiment, such as Figure 8 As shown, the second transmission tube 32 is provided with multiple spring slots, and a second spring 536 is fixedly connected in each spring slot. The second spring 536 is also fixedly connected to the corresponding second ratchet slider 535. At the same time, the second spring 536 is used to push the corresponding second ratchet slider 535 toward the lower outer casing 9 so that the second ratchet slider 535 is engaged in the corresponding second ratchet slot 534.

[0044] When the inner cylinder assembly 200 moves vertically downwards, under the action of the lead screw cylinder 25 and the nut cylinder 52, the first transmission pipe 31, the second transmission pipe 32, and the retrieval cylinder 35 rotate synchronously counterclockwise. At this time, the retrieval cylinder 35 releases the stuck component by reverse clamping. When the inner cylinder assembly 200 moves vertically upwards, under the action of the lead screw cylinder 25 and the nut cylinder 52, the first transmission pipe 31 rotates clockwise. At this time, the second transmission pipe 32 and the retrieval cylinder 35 remain stationary.

[0045] In this embodiment, the first transmission pipe 31 is connected to the support sleeve 7 by a sliding bearing, and the second transmission pipe 32 is connected to the lower outer shell 9 by a sliding bearing and a needle roller bearing. The first transmission pipe 31 and the second transmission pipe 32 are also connected by a sliding bearing so that the first transmission pipe 31 and the second transmission pipe 32 can rotate smoothly.

[0046] In this embodiment, all components between the upper connector 104 and the hydraulic connector 3 can be connected in multiple stages, and the operator can adjust the length of the device according to actual needs. Simultaneously, sealing rings 61 and / or alignment rings 62 can be provided between adjacent interconnected components to improve sealing effect and alignment accuracy.

[0047] The downhole hydraulic reverse connection device in this embodiment is used as follows: The downhole hydraulic reverse coupling device is lowered into the casing via drill pipe. When the retrieval cylinder 35 approaches the fish head, the speed is appropriately reduced. At this point, the wellhead pump is started to flush the downhole fish head. After flushing, the downhole hydraulic reverse coupling device is lowered further to connect with the fish head, and the drill pipe is pulled up appropriately to increase the suspension weight. Subsequently, the plugging ball 42 and sealing ball 415 are deployed in sequence, and the pump is started at a high displacement and low pump pressure for circulation. The pump pressure is checked to determine whether the plugging ball 42 and sealing ball 415 are in place. The drill pipe is then pulled up again to increase the suspension weight, and the pump pressure is increased to ensure that the hydraulic anchor 101 is successfully anchored on the casing. The drill pipe is then lowered again to reduce the suspension weight, locking the hydraulic anchor 101 to the casing.

[0048] Subsequently, the pump pressure is increased further. When the pump pressure increases to the point where it can shear the shear pin 416, the sliding sleeve 414 slides down and aligns the first through hole 417 with the flow channel annular groove 412. At this time, the main flow channel inside the inner cylinder assembly 200 is connected, and the pressurized liquid flows to the main channel. The pump pressure is further increased, and components such as the piston cylinder 23, piston sealing cap, and upper hydraulic center pipe 22 move downwards as a whole, compressing the return spring 433. Simultaneously, the hydraulic oil in the hydraulic annular cavity 44 is discharged through the hydraulic interface 47. At the same time, the lower hydraulic center pipe 24 drives the lead screw cylinder 25 to move downwards. During the downward movement of the lead screw cylinder 25, the nut cylinder 52 rotates counterclockwise. The nut cylinder 52 drives the first transmission pipe 31, the second transmission pipe 32, and the retrieval cylinder 35 to rotate counterclockwise synchronously, causing the retrieval cylinder 35 to begin its inverted position.

[0049] When the inner cylinder assembly 200 moves downward to its maximum stroke, the pressure is stabilized for a few minutes before being released. At this time, the retrieval cylinder 35 will tend to rotate clockwise. However, the second ratchet slider 535 on the second transmission pipe 32 cannot rotate clockwise relative to the lower outer casing 9, so the retrieval cylinder 35 will not rotate clockwise. Subsequently, the hydraulic interface 47 is pressurized through the external hydraulic pipe, and hydraulic oil enters the hydraulic ring cavity 44, and the return spring 433 gradually rebounds. At the same time, the first transmission pipe 31 rotates clockwise, driving the lead screw cylinder 25 to move upward until the return spring 433 returns to its initial state.

[0050] Repeat the above steps multiple times until a sufficient torque is generated to open the fish's head, at which point the pressure curve will show a step change. Finally, pull the drill rod upwards appropriately to increase the suspended weight to a certain tonnage, unlock the hydraulic anchor 101, and pull the drill rod up to retrieve the fish, thus achieving the inverted release operation of the stuck parts.

[0051] It should be noted that, unless otherwise stated, the technical or scientific terms used in this invention should have the ordinary meaning as understood by one of ordinary skill in the art.

[0052] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly defined.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A downhole hydraulic reverse-locking device, characterized in that, include: The outer cylinder assembly (100) is vertically arranged; The inner cylinder assembly (200) is coaxially disposed within the outer cylinder assembly (100); The undercut assembly (300) is coaxially connected to the bottom of the inner cylinder assembly (200) and is used to connect with the locked component; A hydraulic assembly (400) is used to control the movement of the inner cylinder assembly (200) in the vertical direction; A drive assembly (500) is used to control the rotation of the undercut assembly (300).

2. The downhole hydraulic reverse-locking device according to claim 1, characterized in that, The outer cylinder assembly (100) includes, from top to bottom, a connector assembly (1), a hydraulic outer cylinder (2), a hydraulic connector (3), a first short connector (4), a splined outer cylinder (5), a second short connector (6), a support sleeve (7), a third short connector (8), a lower outer shell (9), and a lower end cap (10). The inner cylinder assembly (200) includes, from top to bottom, a hydraulic sealing end cap (21), an upper hydraulic center tube (22), a piston cylinder (23), a lower hydraulic center tube (24), and a lead screw cylinder (25); The inverted assembly (300) includes a first transmission pipe (31), a second transmission pipe (32), a lower connector (33), a lower single-flow ball seat (34), and a retrieval cylinder (35) connected sequentially from top to bottom.

3. The downhole hydraulic reverse-locking device according to claim 2, characterized in that, The hydraulic assembly (400) includes: The sliding sleeve (41) is located inside the connector assembly (1) and can be opened under external pressure. The sealing ball (42) is used to form a sealing fit with the sealing surface inside the lower single-flow ball seat (34) to seal the lower single-flow ball seat (34) so ​​that the inner cylinder assembly (200) can move vertically downward under external pressure. A reset mechanism (43) is used to control the vertical upward movement of the inner cylinder assembly (200).

4. The downhole hydraulic reverse-locking device according to claim 3, characterized in that, The opening sleeve (41) includes: A retaining sleeve (411) is disposed within the connector assembly (1); A flow channel annular groove (412) is provided on the inner wall of the fixed sleeve (411); The first flow channel (413) is multiple and is vertically arranged inside the fixed sleeve (411). The top of the multiple first flow channels (413) is connected to the flow channel annular groove (412). The sliding sleeve (414) is connected to the fixed sleeve (411) by a shear pin (416); The first through hole (417) is provided on the sliding sleeve (414); A sealing ball (415) is used to form a sealing fit with the sealing surface inside the sliding sleeve (414) to seal the sliding sleeve (414); The shear pin (416) can be sheared under external pressure so that the sliding sleeve (414) can move vertically downward and connect the first through hole (417) with the flow channel annular groove (412).

5. The downhole hydraulic reverse-locking device according to claim 4, characterized in that, The lower end of the fixed sleeve (411) is provided with a limiting ring (418). When the sliding sleeve (414) moves downward and forms an abutment with the limiting ring (418), the first through hole (417) is aligned with the flow channel annular groove (412).

6. The downhole hydraulic reverse-locking device according to claim 3, characterized in that, The reset mechanism (43) includes: The upper spring sleeve (431) is connected to the bottom of the piston cylinder (23); The lower spring sleeve (432) is connected to the top of the hydraulic connector (3); The return spring (433) is connected at one end to the upper spring sleeve (431) and at the other end to the lower spring sleeve (432).

7. The downhole hydraulic reverse-locking device according to claim 6, characterized in that, A hydraulic annular cavity (44) is formed between the upper spring sleeve (431), the lower spring sleeve (432) and the lower hydraulic center tube (24), the reset spring (433) is disposed in the hydraulic annular cavity (44), and the hydraulic annular cavity (44) is filled with hydraulic oil; The hydraulic connector (3) has a second flow channel (45) inside, and the lower spring sleeve (432) has a second through hole (46) inside that connects the second flow channel (45) and the hydraulic ring cavity (44). The hydraulic connector (3) has a hydraulic interface (47) that communicates with the second flow channel (45), and the hydraulic interface (47) is used to connect with an external hydraulic pipeline.

8. The downhole hydraulic reverse-locking device according to claim 2, characterized in that, The drive assembly (500) includes: The spline block (51) is disposed on the lead screw cylinder (25) and slides vertically with the spline outer cylinder (5); Nut sleeve (52) is rotatably connected to the support sleeve (7). The nut sleeve (52) is threaded onto the lead screw sleeve (25), and the thread helix angle of the threaded section at the lower end of the lead screw sleeve (25) is greater than 70°, so that the nut sleeve (52) can rotate when the lead screw sleeve (25) moves vertically. The ratchet mechanism (53) is used to restrict the second transmission tube (32) from rotating counterclockwise when the first transmission tube (31) rotates counterclockwise, and the second transmission tube (32) remains stationary when the first transmission tube (31) rotates clockwise.

9. The downhole hydraulic reverse-locking device according to claim 8, characterized in that, The ratchet mechanism (53) includes: There are multiple first ratchet slots (531) respectively disposed on the inner wall of the support sleeve (7), and the multiple first ratchet slots (531) are arranged sequentially along the circumference of the support sleeve (7); The first ratchet slider (532) is slidably connected to the first transmission tube (31) and can cooperate with any of the first ratchet slots (531); Multiple first springs (533) are used to push the corresponding first ratchet sliders (532) toward the support sleeve (7) so that the first ratchet sliders (532) are engaged in the corresponding first ratchet slots (531); There are multiple second ratchet slots (534), which are respectively disposed on the inner wall of the lower outer shell (9). The multiple second ratchet slots (534) are arranged sequentially along the circumference of the lower outer shell (9). The second ratchet slider (535) is slidably connected to the second transmission tube (32) and can cooperate with any of the second ratchet slots (534); There are multiple second springs (536), each used to push the corresponding second ratchet slider (535) toward the lower outer shell (9) so that the second ratchet slider (535) is engaged in the corresponding second ratchet slot (534).

10. The downhole hydraulic reverse-locking device according to claim 2, characterized in that, The connector assembly (1) includes a hydraulic anchor (101), a shear check valve top connector (102), a shear check valve bottom connector (103), and an upper connector (104) connected sequentially from top to bottom, and the upper connector (104) is coaxially connected to the hydraulic outer cylinder (2).

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