Downhole tool for a branched well

Abstract

The utility model provides a kind of downhole tool for branch well, including recovery mechanism, the recovery mechanism includes shell, concentric arrangement in the shell's unlocking nipple, and the locking mechanism being arranged in the annulus of the shell with the unlocking nipple, the anchoring mechanism being arranged below the recovery mechanism, and the setting mechanism being arranged below the anchoring mechanism, wherein, the recovery mechanism further includes the water plug being arranged below unlocking nipple, and the pressure transmission cylinder being arranged below the water plug and respectively with the anchoring mechanism and the setting mechanism form airtight environment.

Description

Technical Field

[0001] This utility model relates to the field of branch well drilling and completion technology, and specifically to a downhole tool for branch wells. Background Technology

[0002] Currently, branch well technology is a rapidly emerging drilling and completion technology in the drilling industry. It can increase the drainage area of ​​oil reservoirs and improve oil and gas production, making it an effective technology for enhancing oil and gas field production. Running production tubing into branch wells, combined with fracturing and acidizing operations, yields the best production enhancement results for oil and gas wells. However, this technology requires complex tools, involves dozens of tripping operations, has a long construction period, and is costly, resulting in poor economic benefits for low-yield oil and gas wells.

[0003] Therefore, it is desirable in the art to provide a downhole tool for branch wells to effectively reduce the number of trips in and out of the well. Summary of the Invention

[0004] The purpose of this invention is to propose a downhole tool for branch wells, which enables the simultaneous installation of a main wellbore plugging device during a single drilling run of the branch well.

[0005] According to this utility model, a downhole tool for branch wells is provided, including a retrieval mechanism. The retrieval mechanism includes a housing, an unlocking sub arranged concentrically within the housing, and a locking mechanism disposed within the annulus between the housing and the unlocking sub. An anchoring mechanism located below the recycling mechanism, and The setting mechanism is located below the anchoring mechanism. The recovery mechanism further includes a water plug located below the unlocking section, and a pressure transmission cylinder located below the water plug and forming a sealed environment with the anchoring mechanism and the setting mechanism, respectively.

[0006] In one embodiment, the downhole tool for the branch well further includes a packer joint disposed below the housing, and a slip seat and a slip cone disposed between the housing and the packer joint. The anchoring mechanism includes an anchoring core tube disposed radially outside the pressure transmitting cylinder, a first slip and a second slip disposed between the slip seat and the slip cone respectively, and a support ring seat for axially limiting the first slip and the second slip.

[0007] In one embodiment, an inner bevel and an outer bevel are provided between the anchoring core tube and the support ring seat to abut against the first slip and the second slip, respectively. The process involves applying pressure to the hollow flow channel formed by the unlocking section and the water plug. The pressure travels along the pressure transmission cylinder and enters through the anchoring core tube, thereby causing the inner buckling slope and the outer buckling slope to move in opposite directions until the first slip and the second slip are anchored on the sleeve.

[0008] In one embodiment, the inner bevel and the outer bevel are initially fixed to the first collet and the second collet respectively by screws, and the ends of the inner bevel and the outer bevel are connected by an anti-reverse thread structure.

[0009] In one embodiment, the downhole tool further includes a core tube disposed radially inside the packer joint, a piston cylinder liner fixed below the packer joint by a backstop ring, and a sealing plug sleeve disposed between the core tube and the piston cylinder liner.

[0010] In one embodiment, the setting mechanism includes a lower sealing joint spaced apart from the piston cylinder liner, at least two sealing tubes disposed between the piston cylinder liner and the lower sealing joint, and a retaining ring disposed between adjacent sealing tubes.

[0011] In one embodiment, a limiting groove is provided on the inner wall of the housing. The locking mechanism includes a locking connector mounted on the unlocking stub and an unlocking cylinder liner sleeved outside the unlocking stub. In the initial state, the unlocking cylinder liner is fixed to the water plug by a shear pin, which causes the locking joint to engage with the limiting groove.

[0012] In one embodiment, a deflector is provided above the housing, and a pressure transmission pipeline communicating with the hollow flow channel is provided inside the deflector.

[0013] In one embodiment, the downhole tool further includes a temporary plugging mechanism disposed below the setting mechanism, the temporary plugging mechanism including a bottom connector and a ceramic cap disposed within the bottom connector for temporarily plugging the pressure transmission cylinder.

[0014] Compared with the prior art, the advantages of this utility model are: This device enables simultaneous drilling and window opening in a branch well, while simultaneously running the main wellbore plugging device, resulting in high operational efficiency. Specifically, after running the entire tubing string, pressure is applied to first anchor the casing, followed by setting the casing. At this point, side-drilling to open the window and proceeding with branch wellbore processing can begin. Furthermore, after completing the processing, the device can retrieve the directional drilling rig and other related structures. Pressure is applied to shear the shear pins to release the locking joint, and then the directional drilling rig is lifted using a retrieval hook to bring the tool string to the wellhead, thus enabling the directional drilling rig retrieval from the main wellbore. In addition, this device effectively reduces the construction cost of branch wells through these multiple design features. Attached Figure Description

[0015] The present invention will now be described in detail with reference to the accompanying drawings, in which: Figure 1 The schematic diagram shows the first part of the structure of a downhole tool for a branch well according to the present invention; Figure 2 The schematic diagram shows the second part of the structure of a downhole tool for a branch well according to the present invention; Figure 3 The schematic diagram shows the third part of the structure of the downhole tool for branch wells according to the present invention; Figure 4 The schematic diagram shows a locking connector in a downhole tool for a branch well according to the present invention; Figure 5 The schematic diagram shows the inner bevel in a downhole tool for a branch well according to the present invention; Figure 6 The schematic diagram shows the external bevel in a downhole tool for a branch well according to the present invention.

[0016] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not drawn to scale. Detailed Implementation

[0017] To make the technical solution and advantages of this utility model clearer, the exemplary embodiments of this utility model will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not an exhaustive list of all embodiments. Furthermore, without conflict, the embodiments and features in the embodiments of this utility model can be combined with each other.

[0018] In the description of this utility model, it should be understood that the terms "first" and "second" 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. Therefore, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature.

[0019] In this utility model, unless otherwise explicitly specified and limited, the terms "installation", "connection", "linking", "fixing" and other such terms should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components.

[0020] Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0021] The present invention will be further described below with reference to the accompanying drawings.

[0022] Figure 1 The schematic diagram shows the first part of the structure of a downhole tool for a branch well according to the present invention. Figure 2 The schematic diagram shows the second part of the structure of a downhole tool for a branch well according to the present invention. Figure 3 The schematic diagram shows the third part of the structure of a downhole tool for a branch well according to the present invention.

[0023] like Figures 1-3 As shown, the downhole tool for branch wells according to this utility model mainly includes a retrieval mechanism, and an anchoring mechanism and a setting mechanism arranged sequentially below the retrieval mechanism. Preferably, the retrieval mechanism includes a housing 11, an unlocking sub 12 concentrically arranged within the housing 11, and a locking mechanism disposed within the annulus between the housing 11 and the unlocking sub 12.

[0024] Figure 4 The schematic diagram shows the locking joint 41 in a downhole tool for a branch well according to the present invention.

[0025] In one embodiment of this utility model, such as Figures 1-4 As shown, a limiting groove 111 is provided on the inner wall of the housing 11, and the locking mechanism includes a locking connector 41 installed on the upper part of the unlocking section 12 via a threaded connection, and an unlocking cylinder sleeve 42 sleeved on the lower part of the unlocked section 12. Preferably, the unlocking cylinder sleeve 42 is fixed to the water plug 13 (described below) in the initial state by a shear pin 421, thereby limiting the locking connector 41 so that the protrusion arranged at its lower end is embedded in the limiting groove 111 to form a firm snap-fit ​​relationship, thereby preventing the locking connector 41 from unlocking prematurely.

[0026] In this utility model, when the side drilling window opening and upper branch well hole treatment are completed and retrieval is required, the shearing nail 421 can be cut by pressure, thereby causing the unlocking cylinder liner 42 to move downward to release the locking joint 41. At this time, the protrusion of the locking joint 41 can pop out from the limiting groove 111, which helps the subsequent retrieval operation.

[0027] In one embodiment, such as Figures 1-3 As shown, a slant 51 is provided above the housing 11. After the slant 51 is embedded into the housing 11, it is first threadedly connected to the locking connector 41, and then fixedly connected to the housing 11 by the fastening screw 511. It is worth noting that the fastening screw 511 needs to be cut off during the subsequent retrieval process to complete the lifting and retrieval operation.

[0028] In one embodiment, such as Figures 1-3 As shown, the recovery mechanism also includes a water plug 13 located below the unlocking sub 12, and a pressure transmission cylinder 14 located below the water plug 13. Preferably, the unlocking sub 12 and the water plug 13 are threaded together; the unlocking cylinder liner 42 and the water plug 13 are fixedly connected by a shear pin 421; and the pressure transmission cylinder 14 and the water plug 13 are threaded together. Thus, during subsequent retrieval operations, the directional tool 51, the unlocking sub 12, the locking joint 41, the unlocking cylinder liner 42, the water plug 13, and the pressure transmission cylinder 14 will be pulled out of the wellhead as a tool string, thereby completing the release operation.

[0029] In one embodiment, such as Figures 1-3 As shown, the downhole tool for the branch well also includes a packer joint 15 disposed below the housing 11, and a slip seat 161 and a slip cone 162 disposed between the housing 11 and the packer joint 15. Meanwhile, the anchoring mechanism includes an anchoring core tube 20 disposed radially outside the pressure transmission cylinder 14, a first slip 21 and a second slip 22 disposed between the slip seat 161 and the slip cone 162 respectively, and a support ring seat 23 for axially limiting the first slip 21 and the second slip 22.

[0030] Preferably, the housing 11 and the slip seat 161 are threaded together; the sealing joint 15 and the slip cone 162 are threaded together.

[0031] Figure 5 The schematic diagram shows the inner bevel 241 in a downhole tool for a branch well according to the present invention. Figure 6 The schematic diagram shows the external inclined surface 242 in a downhole tool for a branch well according to the present invention.

[0032] In one embodiment of this utility model, such as Figure 2 , 5As shown in Figure 6, an inner bevel 241 and an outer bevel 242 are provided between the anchoring core tube 20 and the support ring seat 23, respectively abutting against the first slip 21 and the second slip 22. Preferably, the inner bevel 241 and the outer bevel 242 can be fixed to the first slip 21 and the second slip 22 respectively by screws 243 in the initial state, and the ends of the inner bevel 241 and the outer bevel 242 are connected by an anti-retraction thread structure. Thus, the inner bevel 241 and the outer bevel 242 can only move in opposite directions and cannot move in opposite directions, thereby improving the effectiveness of the anchoring mechanism.

[0033] Preferably, both the first slip 21 and the second slip 22 are constructed in a trapezoidal structure, and both the inner inclined surface 241 and the outer inclined surface 242 are constructed in a geometric shape that is compatible with the first slip 21 and the second slip 22.

[0034] In this invention, hollow flow channels are formed within the unlocking section 12 and the water plug 13. In other words, a straight first flow channel is formed within the unlocking section 12, and an L-shaped second flow channel is formed within the water plug 13. Simultaneously, a pressure-transmitting pipeline 52 communicating with the first flow channel of the unlocking section 12 is formed within the deflector 51. Preferably, the second flow channel communicates with the closed annular space formed by the pressure-transmitting cylinder 14 and the anchoring core tube 20.

[0035] Therefore, after being pressurized through the pressure transmission line 52 of the inclined device 51, the pressure will flow sequentially through the first flow channel of the unlocking section 12 and the second flow channel of the water plug 13 to the closed annular space formed by the pressure transmission cylinder 14 and the anchoring core tube 20, and then enter through the circumferential through hole on the anchoring core tube 20. This will cause the inner inclined surface 241 and the outer inclined surface 242 to move in opposite directions after the screw 243 is cut off, until the first slip 21 and the second slip 22 are anchored on the sleeve.

[0036] Preferably, the slip seat 161 and the support ring seat 23 are an integral structure, and the slip seat 161 has a plurality of hollow square holes. A plurality of first slips 21 are placed in the upper row of square holes, and a plurality of second slips 22 are placed in the lower row of square holes.

[0037] In one embodiment, such as Figures 1-3 As shown, the downhole tool for the branch well also includes a core tube 17 disposed radially inside the packer joint 15, a piston cylinder liner 18 fixed below the packer joint 15 by a backstop ring 181, and a sealing plug sleeve 19 disposed between the core tube 17 and the piston cylinder liner 18.

[0038] Preferably, the sealing joint 15 is threadedly connected to the core tube 17, and the core tube 17 has a threaded structure that matches the anti-reverse ring 181. Simultaneously, a support ring sleeve 182 is provided above the piston cylinder liner 18 and is threadedly connected thereto, with the anti-reverse ring 181 installed inside the support ring sleeve 182. Thus, the piston cylinder liner 18 can only move downwards within the anti-reverse ring 181, thereby ensuring the effectiveness of the setting seal. Preferably, the sealing plug sleeve 19 is threadedly connected to the core tube 17.

[0039] In one embodiment, such as Figure 2 and 3 As shown, the setting mechanism includes a lower sealing connector 31 spaced apart from the piston cylinder liner 18, at least two sealing sleeves 32 disposed between the piston cylinder liner 18 and the lower sealing connector 31, and a retaining ring 33 disposed between adjacent sealing sleeves 32. Preferably, the upper part of the lower sealing connector 31 is threadedly connected to the core tube 17, and the lower part of the lower sealing connector 31 is threadedly connected to the first connector 61.

[0040] In this invention, the core tube 17, the sealing plug sleeve 19, and the piston cylinder sleeve 18 form a sealed annular space. Pressure can then enter this space through the circumferential through-hole on the core tube 17, causing the piston cylinder sleeve 18 to descend and compress the sealing rubber sleeve 32. The sealing rubber sleeve 32 deforms under the action of the retaining ring 33 to form a sealed connection with the inner wall of the sleeve. Preferably, the anti-reverse ring 181 effectively prevents retraction, thus ensuring a smooth setting process.

[0041] In one embodiment, such as Figure 3 As shown, the downhole tools for branch wells also include a temporary plugging mechanism located below the setting mechanism. The temporary plugging mechanism includes a bottom connector and a ceramic cap 64 disposed within the bottom connector for temporarily plugging the pressure transmission cylinder 14. Preferably, after the setting operation is completed, the main wellbore sealing device, such as the ceramic cap 64, can be lowered into the well, thereby enabling side-drilling and branch wellbore treatment operations.

[0042] Preferably, such as Figure 3 As shown, the bottom connector includes a first connector 61 and a second connector 62 arranged at intervals, and a third connector 63 disposed between the first connector 61 and the second connector 62. The first connector 61 and the lower sealing connector 31 are threaded together. The ceramic cover 64 is fixedly installed in the third connector 63 and is fixedly connected by geometric shape to play a temporary blocking role.

[0043] In this invention, after the side-drilling window opening and upper branch wellbore treatment are completed, when the directional drilling tool 51 is retrieved, it is necessary to first pressurize it through the pressure transmission line 52 of the directional drilling tool 51. The pressure will enter the sealed annular space formed by the unlocking short section 12 and the unlocking cylinder liner 42 through the locking joint 14 and along the circumferential through hole on the unlocking short section 12. As the pressure in this space gradually increases, the shear pin 421 will be sheared. At this time, the unlocking cylinder liner 42 moves downward to make room, thereby releasing the locking joint 41. Furthermore, the protrusion of the locking joint 41 can then pop out from the limiting groove 111.

[0044] Afterwards, by lifting the directional device 51 with the retrieval hook, and after cutting the fastening screw 511, the tool string consisting of the directional device 51, the unlocking sub 12, the locking joint 41, the unlocking cylinder liner 42, the water plug 13 and the pressure transmission cylinder 14 can be pulled out of the wellhead, thus completing the hand-drop operation and realizing the work of recovering the directional device 51 in the main wellbore.

[0045] The working steps of this device are described in detail below: First, the anchoring of the sleeve is accomplished through the anchoring mechanism.

[0046] Pressurized by the pressure transmission line 52 of the inclined device 51, the pressure flows sequentially through the first flow channel of the unlocking section 12 and the second flow channel of the water plug 13 to the closed annular space formed by the pressure transmission cylinder 14 and the anchoring core tube 20, and then enters through the circumferential through hole on the anchoring core tube 20. Thus, after the shearing screw 243 is cut, the inner buckling inclined surface 241 and the outer buckling inclined surface 242 move in opposite directions until the first slip 21 and the second slip 22 are anchored on the sleeve.

[0047] Then, the setting mechanism completes the setting of the sleeve.

[0048] Continued pressure allows the pressure to enter the sealed annular space through the circumferential through-hole on the core tube 17, thereby causing the piston cylinder liner 18 to descend and squeeze the sealing rubber cylinder 32. The sealing rubber cylinder 32 deforms under the action of the retaining ring 33 to form a sealing connection with the inner wall of the sleeve, and then the sealing rubber cylinder 32 is seated on the sleeve.

[0049] Afterwards, once the side drilling window opening and upper branch wellbore treatment are completed, the directional drilling tool 51 will be retrieved and recovered.

[0050] First, pressure is applied through the pressure transmission line 52 of the directional diverter 51. The pressure then passes through the locking joint 14 and enters the sealed annular space formed by the unlocking sub 12 and the unlocking cylinder liner 42 through the circumferential through hole on the unlocking sub 12. As the pressure in this space gradually increases, the shear pin 421 is sheared off. At this time, the unlocking cylinder liner 42 moves downward to make room, thereby releasing the locking joint 41. Furthermore, the protrusion of the locking joint 41 can then pop out from the limiting groove 111. The directional diverter 51 is then lifted up using the retrieval hook. After the fastening screw 511 is sheared off, the tool string consisting of the directional diverter 51, unlocking sub 12, locking joint 41, unlocking cylinder liner 42, water plug 13, and pressure transmission cylinder 14 can be pulled out of the wellhead to complete the release operation, thus realizing the retrieval of the directional diverter 51 in the main wellbore.

[0051] Compared with existing technologies, the advantages of this utility model are: This device enables simultaneous drilling and window opening in a branch well, while simultaneously deploying the main wellbore plugging device, resulting in high operational efficiency. Specifically, after deploying the entire tubing string, pressure is applied to first anchor the casing, followed by setting the casing. This allows for side-drilling to open the window and proceeding with branch wellbore processing. Furthermore, after completing the necessary work, the device can retrieve the directional drilling rig 51 and other related structures. By applying pressure to the shear pin 421 to release the locking joint 41, the directional drilling rig 51 can be lifted using the retrieval hook, allowing the tool string to be retrieved from the wellhead, thus enabling the directional drilling rig 51 to be retrieved from the main wellbore. Additionally, this device effectively reduces the construction cost of branch wells through these multiple design features.

[0052] The above are merely preferred embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Those skilled in the art can easily make changes or modifications within the scope of this utility model, and such changes or modifications should be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A downhole tool for branch wells, characterized in that, include: The recycling mechanism includes a housing (11), an unlocking section (12) concentrically arranged within the housing (11), and a locking mechanism disposed within the annular space between the housing (11) and the unlocking section (12). An anchoring mechanism located below the recycling mechanism, and The setting mechanism is located below the anchoring mechanism. The recycling mechanism also includes a water plug (13) located below the unlocking section (12) and a pressure transmission cylinder (14) located below the water plug (13) and forming a sealed environment with the anchoring mechanism and the setting mechanism respectively.

2. The downhole tool for branch wells according to claim 1, characterized in that, The downhole tool for the branch well also includes a packer joint (15) disposed below the housing (11), and a slip seat (161) and a slip cone (162) disposed between the housing (11) and the packer joint (15). The anchoring mechanism includes an anchoring core tube (20) disposed radially outside the pressure transmission cylinder (14), a first slip (21) and a second slip (22) disposed between the slip seat (161) and the slip cone (162) respectively, and a support ring seat (23) for axially limiting the first slip (21) and the second slip (22).

3. The downhole tool for branch wells according to claim 2, characterized in that, An inner bevel (241) and an outer bevel (242) are provided between the anchor core tube (20) and the support ring seat (23) to abut against the first slip (21) and the second slip (22), respectively. The pressure is applied to the hollow flow channel formed by the unlocking section (12) and the water plug (13). The pressure moves along the pressure transmission cylinder (14) and enters through the anchoring core tube (20), thereby causing the inner buckling slope (241) and the outer buckling slope (242) to move in opposite directions until the first slip (21) and the second slip (22) are anchored on the sleeve.

4. The downhole tool for branch wells according to claim 3, characterized in that, The inner bevel (241) and the outer bevel (242) are fixed to the first clip (21) and the second clip (22) respectively by screws (243) in the initial state, and the ends of the inner bevel (241) and the outer bevel (242) are connected by an anti-retraction thread structure.

5. The downhole tool for branch wells according to claim 4, characterized in that, The downhole tool also includes a core tube (17) disposed radially inside the packer joint (15), a piston cylinder liner (18) fixed below the packer joint (15) by a backstop ring (181), and a sealing plug sleeve (19) disposed between the core tube (17) and the piston cylinder liner (18).

6. The downhole tool for branch wells according to claim 5, characterized in that, The setting mechanism includes a lower sealing joint (31) spaced apart from the piston cylinder liner (18), at least two sealing tubes (32) disposed between the piston cylinder liner (18) and the lower sealing joint (31), and a retaining ring (33) disposed between adjacent sealing tubes (32).

7. The downhole tool for branch wells according to any one of claims 1 to 6, characterized in that, A limiting groove (111) is provided on the inner wall of the housing (11). The locking mechanism includes a locking connector (41) mounted on the unlocking stub (12) and an unlocking cylinder liner (42) sleeved on the unlocking stub (12). In the initial state, the unlocking cylinder liner (42) is fixed to the water plug (13) by a shear pin, which causes the locking connector (41) to engage with the limiting groove (111).

8. The downhole tool for branch wells according to any one of claims 3 to 6, characterized in that, An inclinometer (51) is provided above the housing (11), and a pressure transmission line (52) communicating with the hollow flow channel is provided inside the inclinometer (51).

9. The downhole tool for branch wells according to any one of claims 1 to 6, characterized in that, The downhole tool also includes a temporary plugging mechanism located below the setting mechanism. The temporary plugging mechanism includes a bottom connector and a ceramic cap (64) located inside the bottom connector for temporarily plugging the pressure transmission cylinder (14).

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