Hand-releasing tie-back type underground switch well valve with oil sleeve circulation function

Abstract

The releasing tie-back type underground switch well valve with the oil sleeve circulation function comprises a releasing mechanism, the releasing mechanism comprises a first upper connector, one end of the first upper connector is sequentially connected with a connecting short section and a middle mandrel, and the outer side of the middle mandrel is sleeved with a shearing outer cylinder and an anchor fluke outer cylinder which are connected with each other; a locking claw is arranged on the inner side of the anchor fluke outer barrel and connected to the outer side of the middle mandrel in a sleeving mode, the tail of the locking claw penetrates out of the anchor fluke outer barrel, and a releasing mandrel further penetrates through the inner side of the first upper connector, the inner side of the connecting short section and the inner side of the middle mandrel. The device further comprises a switch valve and a tie-back mechanism. The problem that in the prior art, in a deep well, a high-inclination well and a horizontal well, due to the fact that the torque transmission reliability of a tubular column is low, the well cannot be opened and closed in time is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of downhole equipment for oil and gas exploration, and particularly relates to a releasable and retrievable downhole on-off valve with casing-tubing circulation. Background Art

[0002] Oil and natural gas are the lifeblood of the world economy. Oil and gas wells are usually drilled with a rig to create deep holes on the ground, and then oil and natural gas are extracted from underground to the ground. During the drilling process, downhole tools are required to cooperate with packers to operate the on-off well and release the locking of the upper string and the upper string's disengagement above the packer as a downhole blowout preventer.

[0003] Most of the tools used in the current industry to release the locking of the string before disengagement adopt only rotation or a combination of rotation and hydraulics. However, both the method of only rotation and the combination of rotation and hydraulics may be affected by well depth, well inclination, and horizontal section in deep wells, large-angle wells, and horizontal wells, resulting in ineffective transmission of string torque and greatly reducing the reliability of rotation operations.

[0004] In addition, no matter whether the tools used in the industry adopt only rotation or a combination of rotation and hydraulics, their operation methods are relatively single, and more auxiliary tools need to be configured in the string as a remedial measure in case of accidents. However, configuring more auxiliary tools means a greater risk of leakage, and at the same time, it also increases the operation cost.

[0005] At the same time, most of the current downhole on-off valves can only realize the functions of on-off well, upper string disengagement, and retrieval. When the function of casing-tubing circulation needs to be realized after closing the well, before disengagement, or after retrieval and before opening the well, other downhole tools with circulation functions need to be added to the string. Therefore, the more tools are connected to the string, the more sealing parts there are on the string, thus increasing the risk of leakage. At the same time, separate operations are also required, resulting in complex operations and high operation costs. Summary of the Invention

[0006] The purpose of the present invention is to provide a releasable and retrievable downhole on-off valve with casing-tubing circulation, which solves the problem that in deep wells, large-angle wells, and horizontal wells in the prior art, due to the low reliability of string torque transmission, the well cannot be opened and closed in time.

[0007] The technical solution adopted by the present invention is a releasable and retrievable downhole on-off valve with casing-tubing circulation, including a disengagement mechanism. The disengagement mechanism includes a first upper sub, one end of the first upper sub is sequentially connected with a connecting nipple and an intermediate mandrel. The outside of the intermediate mandrel is sleeved with a shear outer cylinder and an anchor outer cylinder which are connected to each other. The inside of the anchor outer cylinder is provided with locking claws. The locking claws are sleeved on the outside of the intermediate mandrel and the tail part penetrates out of the anchor outer cylinder. A release mandrel also passes through the inside of the first upper sub, the connecting nipple, and the intermediate mandrel; A switching valve, the switching valve includes a lower joint, and a ball valve outer cylinder and a sealing outer cylinder are sequentially connected to the upper end of the lower joint. An elastic claw and a ball cage are arranged inside the ball valve outer cylinder, and a ball valve assembly is arranged inside the ball cage; A reconnecting mechanism, which is used to reconnect with the switching valve and perform the well-opening operation.

[0008] The feature of the present invention also lies in that, A rupture disk a is installed on the first upper joint, a shear pin a passes through the connecting nipple, a second annular groove is opened at the position of the release mandrel relative to the shear pin a, and the shear pin a passes through the connecting nipple and extends to the bottom of the second annular groove.

[0009] The shear outer cylinder is close to the connecting nipple side, and a shear pin b passes through the shear outer cylinder. A fourth annular groove is opened at the position of the intermediate mandrel relative to the shear pin b, and the shear pin b passes through the shear outer cylinder and extends to the bottom of the fourth annular groove; There is a connecting space between the shear outer cylinder and the anchor claw outer cylinder, a release lock ring is arranged in the connecting space, and a first annular groove is opened on one side of the intermediate mandrel relative to the release lock ring; The axial gap on the locking claw cooperates with the spline on the intermediate mandrel to transmit torque. An external serrated thread is arranged on the outer side of the tail of the locking claw passing through the anchor claw outer cylinder, and an internal serrated thread matching and meshing with the external serrated thread is arranged on the inner side of the sealing outer cylinder.

[0010] A first combined seal is sleeved on the outer side of one end of the intermediate mandrel away from the connecting nipple, and the axial position of the first combined seal is fixed by a fixed nipple. The fixed nipple is threadedly connected to the intermediate mandrel and sleeved on the outer side of the release mandrel; An inner hole step of the anchor claw outer cylinder is arranged on the inner side of one end of the anchor claw outer cylinder away from the shear outer cylinder, and an elastic claw inner hole step for contracting the locking claw in cooperation with the inner hole step of the anchor claw outer cylinder is arranged on the outer side of the locking claw located in the anchor claw outer cylinder.

[0011] A shear outer cylinder circulation channel is arranged on the shear outer cylinder, an intermediate mandrel circulation / pressure transmission channel is arranged on the intermediate mandrel, and a release mandrel circulation / pressure transmission channel is arranged on the release mandrel; after the release mandrel and the shear outer cylinder are pressurized and moved, the shear outer cylinder circulation channel, the intermediate mandrel circulation / pressure transmission channel and the release mandrel circulation / pressure transmission channel are connected.

[0012] A release mechanism positioning surface is further arranged on the outer surface of the release mandrel, and a sealing outer cylinder positioning surface corresponding to the release mechanism positioning surface is arranged on the inner side of the sealing outer cylinder; The ball cage is threadedly connected to the lower joint, an operating pin is movably connected to the outer surface of the ball cage, the ball head lug on the inner side of the operating pin passes through the ball cage and is movably connected to the ball valve assembly, and the other end of the operating pin is movably connected to the elastic claw.

[0013] On the inner side of one end of the elastic claw connecting the operating pin, there is an inner conical surface of the elastic claw. At the other end of the elastic claw, there are multiple claw ends with gaps distributed. On the outer side of each claw end, there is an outer circular step of the elastic claw, and on the inner side, there is an inner hole step of the elastic claw; On the inner side of the outer cylinder of the ball valve, there is also an elastic claw opening space for accommodating the opening of the elastic claw.

[0014] When the back connection mechanism is of the separate operation type, the back connection mechanism includes a second upper joint, an outer cylinder of the back connection rupture disk, and a spline mandrel. The second upper joint, the outer cylinder of the back connection rupture disk, and the spline mandrel are sequentially connected by threads, and a back connection mandrel is passed through inside. The back connection mandrel is provided with a fifth annular groove corresponding to the position of the second upper joint. A shear pin c is passed through the second upper joint until the bottom of the fifth annular groove; A first anchoring claw is sleeved on the spline mandrel. The head of the first anchoring claw is located between the outer cylinder of the back connection rupture disk and the spline mandrel. The tail of the first anchoring claw passes through between the outer cylinder of the back connection rupture disk and the spline mandrel and is provided with a first anchoring external thread on the outside for connecting with the internal serrated thread. The axial gap of the first anchoring claw cooperates with the spline on the spline mandrel to transmit torque; The spline mandrel is provided with a first back connection mechanism positioning surface corresponding to the positioning surface of the sealing outer cylinder; A second combined seal is also passed through the spline mandrel. The axial position of the second combined seal is fixed by a first fixed joint. The end of the back connection mandrel far from the second upper joint is provided with a seventh annular groove.

[0015] There is a connection space between the outer cylinder of the back connection rupture disk and the spline mandrel. A back connection lock ring is arranged in the connection space. A sixth annular groove is opened on one side of the back connection mandrel relative to the back connection lock ring; A rupture disk b is installed on the outer cylinder of the back connection rupture disk.

[0016] When the back connection mechanism is of the one - time operation type, the back connection mechanism includes a third upper joint. One end of the third upper joint is thread - connected with an insertion mandrel. A second anchoring claw is sleeved on the insertion mandrel. The head of the second anchoring claw is located between the third upper joint and the insertion mandrel. The second anchoring external thread at the tail of the second anchoring claw passes through between the third upper joint and the insertion mandrel for connecting with the internal serrated thread. And the axial gap of the second anchoring claw cooperates with the spline on the insertion mandrel to transmit torque; The insertion mandrel is provided with a second back connection mechanism positioning surface corresponding to the positioning surface of the sealing outer cylinder; A third combined seal is also passed through the insertion mandrel. The axial position of the third combined seal is fixed by a second fixed joint. The end of the insertion mandrel far from the third upper joint is provided with an eighth annular groove.

[0017] The beneficial effects of the present invention are: (1)When the downhole switching well valve of the present invention needs to be released, the release mandrel can be displaced by operating the annulus / inner pipe pressure. When the release mandrel moves, it pulls the elastic claw to complete well closure. After well closure, the shear outer cylinder is pushed towards the connecting nipple by operating the inner pipe pressure, thereby driving the anchor claw outer cylinder to move synchronously. During the movement of the anchor claw outer cylinder, the inner hole step on its inner side contacts the outer circle step on the locking claw, causing the external serrated thread to disengage from the serrated internal thread of the sealing outer cylinder. This process does not require rotating the pipe string operation, completely avoiding the problem of low torque transmission efficiency, and can be used in deep wells, highly deviated wells and horizontal wells.

[0018] (2)After well closure and before release, the present invention can also open the oil-casing circulation channel while releasing the pipe string lock by operating the inner pipe pressure. Therefore, there is no need to use other tools for providing the oil-casing circulation channel in the pipe string. The reduction in the number of tools reduces the leakage risk caused by multiple sealing parts, and at the same time avoids the problem of needing to operate other tools separately to establish the circulation channel, simplifying the operation process. Brief Description of the Drawings

[0019] Figure 1 is a schematic structural diagram of the retrievable and connectable downhole switching well valve with oil-casing circulation of the present invention when first run into the well; Figure 2 is a schematic structural diagram of the release mechanism in the retrievable and connectable downhole switching well valve with oil-casing circulation of the present invention; Figure 3 is Figure 2 an enlarged structural diagram of part A in Figure 4 is a schematic structural diagram of the locking claw in the retrievable and connectable downhole switching well valve with oil-casing circulation of the present invention; Figure 5 is a schematic structural diagram of the switching valve in the retrievable and connectable downhole switching well valve with oil-casing circulation of the present invention; Figure 6 is a schematic structural diagram of the ball cage in the retrievable and connectable downhole switching well valve with oil-casing circulation of the present invention; Figure 7 is a schematic structural diagram of the retrievable and connectable downhole switching well valve with oil-casing circulation of the present invention after operating to close the well; Figure 8 is a schematic structural diagram of the retrievable and connectable downhole switching well valve with oil-casing circulation of the present invention operating to release; Figure 9 is a schematic structural diagram of the first connection mechanism in the retrievable and connectable downhole switching well valve with oil-casing circulation of the present invention; Figure 10 is a schematic structural diagram of the second connection mechanism in the retrievable and connectable downhole switching well valve with oil-casing circulation of the present invention; Figure 11 It is a schematic structural diagram after the first back-connection mechanism of the present invention operates to open the well after back-connection; Figure 12 It is a schematic structural diagram after the second back-connection mechanism of the present invention operates to open the well after back-connection.

[0020] In the figure, 1. First upper joint, 2. Rupture disc a, 3. Shearing pin a, 4. Connecting short section, 5. Release mandrel, 6. Shearing outer cylinder, 7. Shearing pin b, 8. Release lock ring, 9. Intermediate mandrel, 10. Anchor claw outer cylinder, 11. Locking claw, 12. Sealing outer cylinder, 13. First combined seal, 14. Fixed short section, 15. Ball valve outer cylinder, 16. Elastic claw, 17. Operating pin, 18. Ball cage, 19. Ball valve assembly, 20. Pre-tightening spring, 21. Lower joint, 22. Release mechanism positioning surface, 23. Sealing outer cylinder positioning surface, 24. First annular groove, 25. Intermediate mandrel circulation / pressure transmission channel, 26. Shearing outer cylinder circulation channel, 27. Release mandrel circulation / pressure transmission channel, 28. Internal serrated thread, 29. Second annular groove, 30. Third annular groove, 31. Fourth annular groove, 32. Elastic claw opening vacancy, 33. Elastic claw outer circle step, 34. Elastic claw inner hole step, 35. Release mandrel contact surface, 36. Elastic claw inner conical surface, 37. Anchor claw outer cylinder inner hole step, 38. Locking claw outer circle step, 39. External serrated thread, 40. Second upper joint, 41. Back-connection mandrel, 42. Shearing pin c, 43. Fifth annular groove, 44. Rupture disc b, 45. Back-connection rupture disc outer cylinder, 46. Sixth annular groove, 47. Back-connection lock ring, 48. First anchoring claw, 49. Spline mandrel, 50. First anchoring external thread, 51. First back-connection mechanism positioning surface, 52. Second combined seal, 53. First fixed joint, 54. Seventh annular groove, 55. Third upper joint, 56. Insertion mandrel, 57. Second anchoring claw, 58. Second anchoring external thread, 59. Second back-connection mechanism positioning surface, 60. Third combined seal, 61. Second fixed joint, 62. Eighth annular groove. Detailed implementation mode

[0021] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0022] Embodiment 1 The present invention has a releasable back-connectable downhole switch valve with oil-casing circulation, as Figure 1As shown in the figure, it includes a release mechanism. The release mechanism includes a first upper joint 1. One end of the first upper joint 1 is successively connected with a connecting nipple 4 and an intermediate mandrel 9. A shear outer barrel 6 and an anchor claw outer barrel 10 which are connected to each other are sleeved outside the intermediate mandrel 9. A locking claw 11 is arranged inside the anchor claw outer barrel 10. The locking claw 11 is sleeved outside the intermediate mandrel 9 and its tail penetrates through the anchor claw outer barrel 10. A release mandrel 5 also passes through the inside of the first upper joint 1, the connecting nipple and the intermediate mandrel 9; A switching valve. The switching valve includes a lower joint 21. The upper end of the lower joint 21 is successively connected with a ball valve outer barrel 15 and a sealing outer barrel 12. An elastic claw 16 and a ball cage 18 are arranged inside the ball valve outer barrel 15. A ball valve assembly 19 is arranged inside the ball cage 18. One end of the elastic claw 16 is connected with the release mandrel 5, and the other end is connected with the ball valve assembly 19 through an operating pin 17.

[0023] A reconnecting mechanism. The reconnecting mechanism is used to reconnect with the switching valve and perform the well-opening operation.

[0024] As Figure 2 shown in the figure, a rupture disk a2 is installed on the first upper joint 1. A shear pin a3 passes through the connecting nipple 4. A second annular groove 29 is opened at the position of the release mandrel 5 relative to the shear pin a3. The shear pin a3 passes through the connecting nipple 4 and extends to the bottom of the second annular groove 29.

[0025] When the well closing operation needs to be carried out, the rupture disk a2 on the first upper joint 1 is broken by operating the annulus pressure. After the rupture disk a2 is broken, the release mandrel 5 has a tendency to move upward under the influence of the pressure. As the annulus pressure increases, the shear pin a3 is cut off under the action of the second annular groove 29, so as to enable the release mandrel 5 to move relative to the first upper joint 1. During the movement process, since the release mandrel 5 is connected with the elastic claw 16, the elastic claw 16 is driven to move synchronously, so as to realize the rotation of the ball valve assembly 19 and complete the well closing operation.

[0026] Embodiment 2 On the basis of Embodiment 1, as Figure 3 shown in the figure, on the side of the shear outer barrel 6 close to the connecting nipple 4 in the releasable reconnecting downhole switching valve with oil-casing circulation of the present invention, and a shear pin b7 passes through the shear outer barrel 6. A fourth annular groove 31 is opened at the position of the intermediate mandrel 9 relative to the shear pin b7. The shear pin b7 passes through the shear outer barrel 6 and extends to the bottom of the fourth annular groove 31; the relative position of the shear outer barrel 6 and the intermediate mandrel 9 is initially fixed through the shear pin b7.

[0027] Furthermore, a first combined seal 13 is sleeved outside one end of the intermediate mandrel 9 far from the connecting nipple 4, and the axial position of the first combined seal 13 is fixed by a fixed nipple 14. The fixed nipple 14 is threadedly connected with the intermediate mandrel 9 and is sleeved outside the release mandrel 5; an oil-casing seal is formed by the cooperation between the first combined seal 13 and the sealing outer barrel 12.

[0028] There is a connection gap between the outer cylinder 6 and the anchor claw outer cylinder 10 during shearing. A release lock ring 8 is arranged in the connection gap. A first annular groove 24 is formed on one side of the intermediate mandrel 9 relative to the release lock ring 8. The purpose of setting the release lock ring 8 is that when the shear pin b7 is cut off, the outer cylinder 6 and the anchor claw outer cylinder 10 move upward relative to the intermediate mandrel 9, and the release lock ring 8 moves synchronously. When the release lock ring 8 moves into the first annular groove 24, the release lock ring 8 contracts and is stuck in the first annular groove 24, thereby fixing the relative positions of the outer cylinder 6, the anchor claw outer cylinder 10 and the intermediate mandrel 9.

[0029] As Figure 4 shown, the locking claw 11 has a plurality of axial slots. The axial slots on the locking claw 11 cooperate with the splines on the intermediate mandrel 9 to transmit torque. And an external serrated thread 39 is arranged on the outer side of the tail of the locking claw 11. The external serrated thread 39 is arranged on the outer side of the anchor claw outer cylinder 10. In order to ensure the preliminary connection between the release mechanism and the switch valve, an internal serrated thread 28 that matches and meshes with the external serrated thread 39 is arranged on the inner side of the sealing outer cylinder 12.

[0030] Furthermore, in order to ensure the relative positions of the release mechanism and the switch valve when initially installing the switch well valve for the first time underground, a release mechanism positioning surface 22 is further arranged on the outer surface of the release mandrel 5, and a sealing outer cylinder positioning surface 23 corresponding to the release mechanism positioning surface 22 is arranged on the inner side of the sealing outer cylinder 12.

[0031] Furthermore, an inner hole step 37 of the anchor claw outer cylinder is arranged on the inner side of one end of the anchor claw outer cylinder 10 away from the outer cylinder 6 during shearing. An elastic claw inner hole step 38 that cooperates with the inner hole step 37 of the anchor claw outer cylinder to contract the locking claw 11 is arranged on the outer side of the locking claw 11 located on the anchor claw outer cylinder 10.

[0032] When unlocking is required, through-hole pressurization is performed. The outer cylinder 6 and the anchor claw outer cylinder 10 generate upward power under the action of pressure. Under the action of the fourth annular groove 31, the shear pin b7 is cut off, and the outer cylinder 6 and the anchor claw outer cylinder 10 move relative to the intermediate mandrel 9. At the same time, the release lock ring 8 installed in the connection gap between the outer cylinder 6 and the anchor claw outer cylinder 10 moves to the position of the first annular groove 24 and contracts under the drive of the outer cylinder 6 and the anchor claw outer cylinder 10, thereby finally locking the relative positions of the outer cylinder 6, the anchor claw outer cylinder 10 and the intermediate mandrel 9.

[0033] During this process, since the external sawtooth thread 39 of the locking claw 11 and the internal sawtooth thread 28 of the sealing outer tube 12 are initially in a screwed and locked state, the locking claw 11 does not move relative to the sealing outer tube 12 when the fluke outer tube 10 moves. When the fluke outer tube inner hole step 37 on the fluke outer tube 10 moves to the locking claw outer circle step 38 on the locking claw 11, the outer diameter of the locking claw 11 is contracted, so that the external sawtooth thread 39 is disengaged from the inner inner sawtooth thread 28 of the sealing outer tube 12 that is matched and meshed, thereby releasing the locking state of the locking claw 11 and the sealing outer tube 12.

[0034] At this time, the well closing operation and the locking release operation are completed, the release mechanism and the switch valve are separated, and the release mechanism can be directly pulled out to complete the release operation.

[0035] The downhole switch valves described in Examples 1 and 2 are suitable for downhole operation scenarios where there is no oil casing circulation or where an oil casing circulation function tool is installed on the tubing. However, when the oil casing circulation function is required for downhole operations, installing an oil casing circulation tool on the tubing will increase the risk of leakage of the tubing itself. At the same time, additional operation of the oil casing circulation tool is required, which increases the complexity of the operation and increases the operation cost.

[0036] Example 3 This embodiment is based on the above embodiment. Figure 3 As shown, in the detachable reconnectable downhole switch well valve with oil casing circulation of the present invention, a shear outer cylinder circulation channel 26 is provided on the shear outer cylinder 6, an intermediate core shaft circulation / pressure transmission channel 25 is provided on the intermediate core shaft 9, and a detachable core shaft circulation / pressure transmission channel 27 is provided on the detachable core shaft 5; after the detachable core shaft 5 and the shear outer cylinder 6 are pressurized and moved, the shear outer cylinder circulation channel 26, the intermediate core shaft circulation / pressure transmission channel 25 and the detachable core shaft circulation / pressure transmission channel 27 are connected.

[0037] Specifically, after the well shut-in operation is completed, as the release spindle 5 moves, the intermediate spindle circulation / pressure transmission channel 25 and the release spindle circulation / pressure transmission channel 27 are connected to prepare for the unlocking operation. When the unlocking operation is performed, the pressure pushes the shear outer cylinder 6 and the anchor claw outer cylinder 10 to move upward through the connected intermediate spindle circulation / pressure transmission channel 25 and the release spindle circulation / pressure transmission channel 27, so that the shear pin b7 is sheared by the fourth annular groove 31.

[0038] When the unlocking operation is completed, the middle core shaft circulation / pressure transmission channel 25, the shear outer cylinder circulation channel 26 and the release core shaft circulation / pressure transmission channel 27 are connected, and a channel with a certain flow area is formed between the diameter of the release mechanism and the annulus. The liquid in the annulus and the diameter can be circulated in the required direction through this channel, thereby eliminating the need to separately install tools with circulation functions on the tubing, reducing operating costs and improving operating efficiency.

[0039] Embodiment 4 Based on the above embodiments, as Figure 5 shown, the constant velocity joint 18 is threadedly connected to the lower joint 21. An operating pin 17 is movably connected to the outer surface of the constant velocity joint 18. Specifically, the outer circular groove at the right end of the elastic claw 16 is engaged with the inner arc groove at the left end of the operating pin 17. The ball head lug on the inner side of the operating pin 17 passes through the constant velocity joint 18 and is movably connected to the ball valve assembly 19. A preloading spring 20 is further provided between the ball valve assembly 19 and the lower joint 21. As Figure 6 shown, a through groove is formed in the constant velocity joint 18 to facilitate the connection between the ball head lug on the inner side of the operating pin 17 and the ball valve assembly 19 through the through groove.

[0040] The other end of the operating pin 17 is movably connected to the elastic claw 16. An inner conical surface 36 of the elastic claw is provided on the inner side of the elastic claw 16 at the end connected to the operating pin 17. Multiple claw ends with gaps are distributed at the other end of the elastic claw 16. An outer circular step 33 of the elastic claw is provided on the outer side of each claw end, and an inner hole step 34 of the elastic claw is provided on the inner side. An elastic claw opening space 32 for accommodating the opening of the elastic claw 16 is further provided inside the outer cylinder 15 of the ball valve.

[0041] That is, when installing the downhole on-off well valve, the contact surface 35 of the releasing mandrel 5 at the lower end of the releasing mandrel contacts and abuts against the inner conical surface 36 of the elastic claw. As the releasing mandrel 5 continues to extend, it drives the elastic claw 16 to move downward. The outer circular step 33 of the claw end is squeezed by the outer cylinder 15 of the ball valve, so that the inner hole step 34 of the elastic claw is stuck in the third annular groove 30, thus completing the connection between the releasing mandrel 5 and the elastic claw 16.

[0042] When the releasing mechanism of this embodiment performs the well closing operation, as Figure 7 shown, the rupture disk a2 is broken by operating the annulus pressure. The pressure pushes the releasing mandrel 5 to move upward. During the movement, the second annular groove 29 shears the shear pin a3, and the third annular groove 30 pulls the inner hole step 34 of the elastic claw, thereby pulling the elastic claw 16, driving the operating pin 17 and the ball valve assembly 19 to rotate 90° to close the inner diameter.

[0043] During this process, when the outer circular step 33 of the elastic claw 16 moves to the elastic claw opening space 32, it opens from its initial contracted state, releasing the connection between the elastic claw 16 and the releasing mandrel 5. At the same time, the outer circular step 33 of the elastic claw moves to the elastic claw opening space 32 and opens to axially fix the elastic claw 16. Due to the opening of the elastic claw 16, the inner diameter of the inner hole step 34 of the elastic claw is greater than that of the releasing mandrel 5 at this time, enabling the releasing mandrel 5 to continue to move. After the releasing mandrel 5 moves in place, the intermediate mandrel circulation / pressure transmission channel 25 is communicated with the releasing mandrel circulation / pressure transmission channel 27.

[0044] When performing the unlocking operation, pressure is transmitted through the already connected intermediate mandrel circulation / pressure transmission channel 25 and the release mandrel circulation / pressure transmission channel 27 to push the shear outer cylinder 6 and the anchor claw outer cylinder 10 upward. At this time, the shear pin b7 that fixes the relative positions of the shear outer cylinder 6 and the anchor claw outer cylinder 10 and the intermediate mandrel 9 is cut by the intermediate mandrel 9. At the same time, the lock ring 8 moves together with the shear outer cylinder 6 and the anchor claw outer cylinder 10 to the position of the first annular groove 24 and then contracts, thereby finally locking the relative positions of the shear outer cylinder 6 and the anchor claw outer cylinder 10 and the intermediate mandrel 9.

[0045] During this process, since the external serrated thread 39 of the locking claw 11 and the internal serrated thread 28 of the sealing outer cylinder 12 are in a screwed and locked state in the initial state, the locking claw 11 remains stationary relative to the sealing outer cylinder 12 when the anchor claw outer cylinder 10 moves. When the inner hole step 37 of the anchor claw outer cylinder on the anchor claw outer cylinder 10 moves to the outer circle step 38 of the locking claw on the locking claw 11, the outer diameter of the locking claw 11 is contracted, thereby releasing the locked state between the locking claw 11 and the sealing outer cylinder 12.

[0046] As Figure 8 shown, after the operation of closing the well and unlocking, the release mechanism can be withdrawn from the switching valve to complete the release action.

[0047] Embodiment 5 On the basis of the above Embodiment 4, when the retrieving mechanism of the retrievable and connectable downhole switching valve with casing-tubing circulation of the present invention is of the separate operation type, as Figure 9 shown, the retrieving mechanism includes a second upper joint 40, a retrieving rupture disk outer cylinder 45 and a splined mandrel 49. The second upper joint 40, the retrieving rupture disk outer cylinder 45 and the splined mandrel 49 are sequentially connected by threads, and a rupture disk b44 is installed on the retrieving rupture disk outer cylinder 45.

[0048] A retrieving mandrel 41 passes through the second upper joint 40, the retrieving rupture disk outer cylinder 45 and the splined mandrel 49. A fifth annular groove 43 is provided at the position of the retrieving mandrel 41 corresponding to the second upper joint 40. A shear pin c42 is inserted through the second upper joint 40 until it reaches the bottom of the fifth annular groove 43.

[0049] A first anchoring claw 48 is sleeved on the splined mandrel 49. The head of the first anchoring claw 48 is located between the retrieving rupture disk outer cylinder 45 and the splined mandrel 49. The first anchoring external thread 50 at the tail of the first anchoring claw 48 passes through the space between the retrieving rupture disk outer cylinder 45 and the splined mandrel 49 for connection with the internal serrated thread 28. The axial gap of the first anchoring claw 48 cooperates with the splines on the splined mandrel 49 to transmit torque; a first retrieving mechanism positioning surface 51 is provided on the splined mandrel 49; A second combined seal 52 is also sleeved on the spline mandrel 49. The axial position of the second combined seal 52 is fixed by a first fixed joint 53. A seventh annular groove 54 is formed at one end of the back connection mandrel 41 away from the second upper joint 40.

[0050] Furthermore, there is a connection gap between the back connection rupture disc outer cylinder 45 and the spline mandrel 49. A back connection lock ring 47 is arranged in the connection gap. A sixth annular groove 46 is formed on one side of the back connection mandrel 41 relative to the back connection lock ring 47.

[0051] When a split-operation type back connection mechanism is used for back connection operation, as Figure 11 shown, the split-operation type back connection mechanism is installed at the lower end of the back connection string. The back connection mechanism is lowered into the well together with the string. As the lower end of the back connection mandrel 41 and the second combined seal 52 on the spline mandrel 49 slowly enter the inside of the seal outer cylinder 12, an oil-casing isolation is formed between the back connection mechanism and the seal outer cylinder 12 until the first back connection mechanism positioning surface 51 contacts the seal outer cylinder positioning surface 23, completing the back connection operation; During the process of the first back connection mechanism positioning surface 51 contacting the seal outer cylinder positioning surface 23, the first anchor external thread 50 on the first anchor claw 48 touches the internal serrated thread 28 as the string descends. Since the structure of the first anchor claw 48 is the same as that of the locking claw 11, the position of the first anchor claw 48 relative to the first anchor external thread 50 is squeezed and contracted inward by the internal serrated thread 28. By the end of the back connection operation, the tail of the first anchor claw 48 automatically opens, realizing the mutual engagement of the first anchor external thread 50 and the internal serrated thread 28.

[0052] When opening the well is required, the rupture disc b44 is broken by applying pressure through the annulus. Under the action of the annulus pressure, the back connection mandrel 41 is pushed downward. The lower end surface of the back connection mandrel 41 abuts against the inner conical surface 36 of the elastic claw, causing the claw end of the elastic claw 16 to contract into the seventh annular groove 54. As the back connection mandrel 41 continues to move downward, since the elastic claw 16 is relatively fixed to the back connection mandrel 41, under the action of the back connection mandrel 41, the elastic claw 16 moves downward, driving the operating pin 17 to push the ball in the ball valve assembly 19 to rotate 90°, realizing the well-opening operation.

[0053] To prevent the back connection mandrel 41 from moving upward due to the flow of the through-diameter liquid after back connection and driving the ball valve assembly 19 to close, after the back connection mandrel 41 completes the well-opening operation, the back connection lock ring 47 will contract into the sixth annular groove 46, making the back connection mandrel 41 relatively fixed to the back connection rupture disc outer cylinder 45 and the spline mandrel 49.

[0054] When an unexpected situation occurs in the present invention, such as when the locking state of the releasing mechanism and the switching valve cannot be released by applying pressure inside the pipe string after closing the well by applying pressure in the annulus, or when it is impossible to close the well by applying pressure in the annulus and the locking state of the releasing mechanism and the switching valve cannot be released, the locking of the pipe string before releasing can be released by means of an alternative rotational operation method to complete the closing of the switching valve and the detachment of the releasing mechanism from the switching valve. The working process is that rotating the pipe string drives the first upper joint 1, the connecting nipple 4, and the intermediate mandrel 9 to rotate. The splines on the intermediate mandrel 9 drive the locking claw 11 and the sealing outer cylinder 12 to rotate relative to each other, causing the internal serrated thread 28 and the external serrated thread 39 to unthread. At this time, lifting the pipe string releasing mechanism can be detached from the switching valve. At the same time, releasing the locking of the pipe string before releasing by applying pressure in the annulus can also be used as an alternative method for rotational operation.

[0055] After the tie-back well is opened, if it is necessary to operate the tie-back mechanism for releasing and closing the well: The action process is that rotating the pipe string drives the second upper joint 40 or the third upper joint 55, the tie-back rupture disk outer cylinder 45, and the spline mandrel 49 or the inserted mandrel 56. The splines on the spline mandrel 49 or the inserted mandrel 56 drive the first anchoring claw 48 or the second anchoring claw 57 to rotate relative to the sealing outer cylinder 12, causing the internal serrated thread 28 and the first anchoring external thread 50 or the second anchoring external thread 58 to unthread. At this time, lifting the pipe string releasing mechanism can be detached from the switching valve.

[0056] Embodiment 6 Based on Embodiment 4, when the tie-back mechanism of the releasable tie-back downhole switching well valve with oil-casing circulation of the present invention is of the one-time operation type, such as Figure 10 As shown, the tie-back mechanism includes a third upper joint 55. One end of the third upper joint 55 is threadedly connected to an inserted mandrel 56. A second anchoring claw 57 is sleeved on the inserted mandrel 56. The head of the second anchoring claw 57 is located between the third upper joint 55 and the inserted mandrel 56. The second anchoring external thread 58 at the tail of the second anchoring claw 57 passes through between the third upper joint 55 and the inserted mandrel 56 for connection with the internal serrated thread 28. And the axial gap of the second anchoring claw 57 cooperates with the splines on the inserted mandrel 56 to transmit torque; a second tie-back mechanism positioning surface 59 is provided on the inserted mandrel 56; A third combined seal 60 is also penetrated on the inserted mandrel 56. The axial position of the third combined seal 60 is fixed by a second fixed joint 61. An eighth annular groove 62 is opened at one end of the inserted mandrel 56 away from the third upper joint 55.

[0057] When using the one-time operation type tie-back mechanism for tie-back operation, such as Figure 12As shown, a one - operation type back - connection mechanism is installed at the lower end of the pipe string. The back - connection mechanism is lowered into the well together with the pipe string. As the lower end of the insertion mandrel 56 and the third combined seal 60 on the insertion mandrel 56 slowly enter the inside of the sealing outer cylinder 12, an oil - casing isolation is formed between the back - connection mechanism and the sealing outer cylinder 12 until the second back - connection mechanism positioning surface 59 contacts the sealing outer cylinder positioning surface 23, completing the back - connection operation. At the same time as the back - connection operation is completed, the second anchor external thread 58 on the outer circle of the right end of the second anchor claw 57 automatically contracts when it touches the internal serrated thread 28 as the pipe string descends, and the second anchor claw 57 automatically opens when the back - connection action is completed, so that the second anchor external thread 58 engages with the internal serrated thread 28 of the sealing outer cylinder 12 to achieve the purpose of anchoring. At the same time, the claw end of the elastic claw 16 contracts into the eighth annular groove 62. As the back - connection operation continues to descend, under the action of the insertion mandrel 56, the elastic claw 16 moves downward, driving the operation pin 17 to push the sphere in the ball valve assembly 19 to rotate 90°, synchronously realizing the well - opening operation.

[0058] That is, when the back - connection mechanism is of the one - operation type, anchoring and well - opening operations are carried out synchronously during back - connection.

[0059] In this specification, the various embodiments are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other.

[0060] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A retrievable and reconnectable downhole switching valve with tubing-casing circulation, characterized in that It includes a releasing mechanism, and the releasing mechanism includes a first upper sub (1). One end of the first upper sub (1) is successively connected with a connecting nipple (4) and an intermediate mandrel (9). The outer side of the intermediate mandrel (9) is sleeved with a shear outer cylinder (6) and an anchor claw outer cylinder (10) which are connected to each other. An anchor claw (11) is arranged inside the anchor claw outer cylinder (10). The anchor claw (11) is sleeved on the outer side of the intermediate mandrel (9), and its tail penetrates through the anchor claw outer cylinder (10). A releasing mandrel (5) also passes through the inside of the first upper sub (1), the connecting nipple and the intermediate mandrel (9); A switching valve, and the switching valve includes a lower sub (21). The upper end of the lower sub (21) is successively connected with a ball valve outer cylinder (15) and a sealing outer cylinder (12). An elastic claw (16) and a ball cage (18) are arranged inside the ball valve outer cylinder (15). A ball valve assembly (19) is arranged inside the ball cage (18); A reconnecting mechanism, and the reconnecting mechanism is used to reconnect with the switching valve and perform a well-opening operation.

2. The retrievable and re-connectable downhole switching valve with tubing-casing circulation according to claim 1, wherein A rupture disk a (2) is installed on the first upper sub (1). A shear pin a (3) passes through the connecting nipple (4). A second annular groove (29) is formed at the position of the releasing mandrel (5) relative to the shear pin a (3). The shear pin a (3) passes through the connecting nipple (4) and extends to the bottom of the second annular groove (29).

3. The retrievable tie-back downhole switching valve with tubing-casing circulation according to claim 1, wherein On the side of the shear outer cylinder (6) close to the connecting nipple (4), a shear pin b (7) passes through the shear outer cylinder (6). A fourth annular groove (31) is formed at the position of the intermediate mandrel (9) relative to the shear pin b (7). The shear pin b (7) passes through the shear outer cylinder (6) and extends to the bottom of the fourth annular groove (31); There is a connecting space between the shear outer cylinder (6) and the anchor claw outer cylinder (10). A releasing lock ring (8) is arranged in the connecting space. A first annular groove (24) is formed on one side of the intermediate mandrel (9) relative to the releasing lock ring (8); The axial gap on the anchor claw (11) cooperates with the spline on the intermediate mandrel (9) to transmit torque. An external serrated thread (39) is arranged on the outer side of the tail of the anchor claw (11) passing through the anchor claw outer cylinder (10). An internal serrated thread (28) matching and meshing with the external serrated thread (39) is arranged inside the sealing outer cylinder (12).

4. The retrievable and re-connectable downhole on-off valve with tubing-casing circulation according to claim 3, wherein A first combined seal (13) is sleeved on the outer side of one end of the intermediate mandrel (9) far from the connecting nipple (4). And the axial position of the first combined seal (13) is fixed by a fixed nipple (14). The fixed nipple (14) is threadedly connected with the intermediate mandrel (9) and sleeved on the outer side of the releasing mandrel (5); An inner hole step (37) of the anchor claw outer cylinder is arranged inside one end of the anchor claw outer cylinder (10) far from the shear outer cylinder (6). An elastic claw inner hole step (38) for contracting the anchor claw (11) in cooperation with the inner hole step (37) of the anchor claw outer cylinder is arranged on the outer side of the anchor claw (11) located in the anchor claw outer cylinder (10).

5. The retrievable tie-back downhole on-off valve with tubing-casing circulation according to claim 1, wherein The shear outer cylinder (6) is provided with a shear outer cylinder circulation channel (26), the intermediate spindle (9) is provided with an intermediate spindle circulation / pressure transmission channel (25), and the hand-off spindle (5) is provided with a hand-off spindle circulation / pressure transmission channel (27); after the hand-off spindle (5) and the shear outer cylinder (6) are pressurized and moved, the shear outer cylinder circulation channel (26), the intermediate spindle circulation / pressure transmission channel (25) and the hand-off spindle circulation / pressure transmission channel (27) are connected.

6. The retrievable and connectable downhole on-off valve with casing-tubing circulation according to claim 1, wherein The outer surface of the release spindle (5) is also provided with a release mechanism positioning surface (22), and the inner side of the sealing outer cylinder (12) is provided with a sealing outer cylinder positioning surface (23) corresponding to the release mechanism positioning surface (22); The ball cage (18) is threadedly connected to the lower joint (21); an operating pin (17) is movably connected to the outer surface of the ball cage (18); a ball head lug on the inner side of the operating pin (17) passes through the ball cage (18) and is movably connected to the ball valve assembly (19); and the other end of the operating pin (17) is movably connected to the elastic claw (16).

7. The retrievable tie-back downhole switching valve with tubing-casing circulation according to claim 6, characterized in that, An elastic claw inner conical surface (36) is arranged on the inner side of one end of the elastic claw (16) connected to the operating pin (17); a plurality of claw ends with gaps are arranged on the other end of the elastic claw (16); an elastic claw outer circular step (33) is arranged on the outer side of each claw end, and an elastic claw inner hole step (34) is arranged on the inner side; An elastic claw opening space (32) for accommodating the opening of the elastic claw (16) is also provided on the inner side of the ball valve outer tube (15).

8. The retrievable and re-connectable downhole switching valve with tubing-casing circulation according to claim 6, wherein, When the tie-back mechanism is of the separately operated type, the tie-back mechanism comprises a second upper joint (40), a tie-back rupture disk outer tube (45) and a splined mandrel (49); the second upper joint (40), the tie-back rupture disk outer tube (45) and the splined mandrel (49) are connected in sequence by threads, and a tie-back mandrel (41) is passed through the interior; a fifth annular groove (43) is formed on the tie-back mandrel (41) at a position corresponding to the second upper joint (40); a shear pin c (42) is passed through the second upper joint (40), and the shear pin c (42) passes through the second upper joint (40) until the bottom of the fifth annular groove (43); A first anchor claw (48) is sleeved on the spline spindle (49); the head of the first anchor claw (48) is located between the tie-back rupture disk outer cylinder (45) and the spline spindle (49); the tail of the first anchor claw (48) passes through between the tie-back rupture disk outer cylinder (45) and the spline spindle (49) and is provided with a first anchor external thread (50) on the outer side for connecting with the internal sawtooth thread (28); the axial gap of the first anchor claw (48) cooperates with the spline on the spline spindle (49) to transmit torque; and a first tie-back mechanism positioning surface (51) corresponding to the sealing outer cylinder positioning surface (23) is provided on the spline spindle (49); The spline spindle (49) is also provided with a second combined seal (52), the axial position of the second combined seal (52) being fixed by a first fixed joint (53), and a seventh annular groove (54) is formed at one end of the return spindle (41) away from the second upper joint (40).

9. The retrievable and re-connectable downhole switching valve with tubing-casing circulation according to claim 8, wherein There is a connecting gap between the outer cylinder (45) of the back connection rupture disk and the spline mandrel (49), and a back connection lock ring (47) is arranged in the connecting gap. A sixth annular groove (46) is formed on one side of the back connection mandrel (41) relative to the back connection lock ring (47); A rupture disk b (44) is installed on the outer cylinder (45) of the back connection rupture disk.

10. The retrievable and reconnectable downhole switching valve with casing-tubing circulation according to claim 6, wherein When the back connection mechanism is of the one-time operation type, the back connection mechanism includes a third upper sub (55). One end of the third upper sub (55) is threadedly connected with an insertion mandrel (56). A second anchoring claw (57) is sleeved on the insertion mandrel (56). The head of the second anchoring claw (57) is located between the third upper sub (55) and the insertion mandrel (56). The second anchoring external thread (58) at the tail of the second anchoring claw (57) passes through between the third upper sub (55) and the insertion mandrel (56) for connection with the internal serrated thread (28). And the axial gap of the second anchoring claw (57) cooperates with the spline on the insertion mandrel (56) to transmit torque. A second back connection mechanism positioning surface (59) corresponding to the sealing outer cylinder positioning surface (23) is arranged on the insertion mandrel (56); A third combined seal (60) is also penetrated on the insertion mandrel (56). The axial position of the third combined seal (60) is fixed by a second fixed sub (61). An eighth annular groove (62) is formed at one end of the insertion mandrel (56) away from the third upper sub (55).

Images