A sliding sleeve opening tool

Abstract

The application provides a sliding sleeve opening tool, which comprises a spring plate mechanism, which is radially expanded under the action of pressure difference and mechanically matched with a groove of a sliding sleeve; an inflatable rubber sleeve, which is arranged at the upper end of the spring plate mechanism, expands to block a pipe string after being put into an opening device; and a releasing sub, which is arranged at the upper end of the inflatable rubber sleeve, is separated from the inflatable rubber sleeve after the inflatable rubber sleeve expands; wherein the sliding sleeve opening tool is sent to a target sliding sleeve position of a well bore, the spring plate mechanism is opened by pressure difference to be matched with the groove of the sliding sleeve; after being put into the opening device, the inflatable rubber sleeve expands to block the pipe string and separates the releasing sub from the inflatable rubber sleeve, and releasing is realized. The application can smoothly open the target sliding sleeve after passing through a pipe string deformation point and reliably seal an inner space of the pipe string, so that smooth fracturing construction is ensured, and the operation success rate of a pipe string deformation well is improved.

Description

Technical Field

[0001] This invention relates to a sliding sleeve opening tool, belonging to the field of oil and gas reservoir stimulation technology. Background Technology

[0002] The fracturing sleeve is a core downhole tool for reservoir stimulation. In practice, the fracturing holes on the sleeve are opened by dropping a ball or using other opening tools to create pressure, and then fracturing operations are carried out on the oil and gas well.

[0003] In recent years, to meet the requirements of more segments in horizontal wells, an opening tool has been developed. This tool is engaged in a groove in the sliding sleeve, and pressure is applied to it, causing it to move and ultimately move the sliding sleeve to open the fracturing hole. While using an opening tool to open the sliding sleeve can accommodate wells with a large number of segments, the gap between the existing opening tool and the sliding sleeve is too small. If there is tubing deformation, such as casing deformation in shale gas wells, the existing opening tool may not be able to pass through the deformation point to open the sliding sleeve, posing a risk of losing the producing layer. Although small-sized bridge plugs or small-sized tubing strings exist to address wells with deformed tubing strings, small-sized bridge plugs carry the risk of accidental jamming or setting inside the sliding sleeve, while small-sized tubing strings have limitations in operating capacity and are expensive.

[0004] Therefore, how to effectively improve the passability between the existing opening tool and the sliding sleeve, while ensuring that the space inside the tube can be successfully sealed after passing through, is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of the above-mentioned technical problems existing in the prior art, the present invention proposes a sliding sleeve opening tool, which can open the target sliding sleeve smoothly after passing through the deformation point of the tubing string and reliably seal the space inside the pipe, thereby ensuring smooth fracturing construction and improving the success rate of well operation in tubing string deformation.

[0006] This invention proposes a sliding sleeve opening tool, comprising:

[0007] A spring mechanism, which expands radially under the action of pressure difference and mechanically pairs with the groove of the sliding sleeve;

[0008] An expandable rubber sleeve disposed at the upper end of the spring mechanism expands and seals the tubing after the opening device is engaged; and

[0009] A release connector is provided at the upper end of the expandable rubber sleeve, and the release connector separates from the expandable rubber sleeve after the expandable rubber sleeve expands.

[0010] In this process, after the sliding sleeve opening tool is inserted into the target sliding sleeve position in the wellbore, the spring plate mechanism is activated by the pressure difference to make it align with the groove of the sliding sleeve; after the opening device is engaged, the expandable rubber sleeve expands to block the tubing string and separates the release connector from the expandable rubber sleeve, thereby achieving release.

[0011] A further improvement of the present invention is that the expandable rubber sleeve includes an upper sleeve connected to the release connector and a lower sleeve connected to the spring mechanism; an expandable rubber sleeve is sleeved on the outside of the lower sleeve, and an inlet hole communicating with the expandable rubber sleeve is provided on the outer wall of the lower sleeve.

[0012] The upper sleeve is provided with a ball seat that blocks the liquid inlet hole. After the opening device is connected, the ball seat moves downward to expose the liquid inlet hole.

[0013] A further improvement of the present invention is that the ball seat and the upper sleeve are connected by a first pin, and a central hole for fluid flow is provided in the middle of the ball seat; the opening device is engaged with the ball seat to block the central hole, so that the upper part of the ball seat is compressed. When the pressure increases to a certain value, the first pin is sheared, and the ball seat moves downward under the pressure.

[0014] A further improvement of the present invention is that the lower end of the release connector is provided with a plurality of elastic pieces, and the outer side of the bottom end of the elastic pieces is provided with a protruding structure; the inner side of the upper sleeve is provided with a groove, and the protruding structure is disposed in the groove.

[0015] In its initial position, the ball seat blocks the inner side of the elastic sheet, causing its protruding structure to engage in the slot; when the ball seat is removed, the inner side of the elastic sheet loses support, causing the protruding structure to slide out of the slot.

[0016] A further improvement of the present invention is that the spring mechanism includes a plurality of springs disposed at the lower end of the expandable rubber sleeve, the springs being arranged circumferentially and capable of being expanded radially; a central stop rod is disposed in the middle of the springs, and when the central stop rod moves downward under the action of pressure difference, it pushes the springs to expand radially.

[0017] A further improvement of the present invention is that the spring is initially provided with a plurality of spring limiting rings on its outer side. When the thrust of the central plug rod on the spring reaches a certain value, the spring limiting rings are sheared, causing the spring to open.

[0018] A further improvement of the present invention is that the bottom of the spring is provided with an inclined surface, and the bottom of the central plug rod is provided with a conical surface; the conical surface cooperates with the inclined surface to convert the axial pressure of the central plug rod into radial thrust.

[0019] A further improvement of the present invention is that a central hole is provided in the middle of the central plug rod, and a pressure differential surface is formed at the upper end; and the upper part of the central plug rod is connected to the expansion rubber sleeve by a second pin.

[0020] A further improvement of the present invention is that a C-shaped ring capable of being radially spring-opening is provided on the outer wall of the upper part of the central plug rod, and an annular groove that mates with the C-shaped ring is provided on the inner side of the lower part of the expandable rubber sleeve; when the central plug rod moves to the position where the spring is fully opened, the C-shaped ring is engaged in the annular groove.

[0021] A further improvement of the present invention is that the sliding sleeve opening tool is made of a soluble material, which can be dissolved by injecting a dissolving liquid or well flowback fluid after fracturing operations, thereby achieving wellbore unblocking.

[0022] Compared with the prior art, the advantages of the present invention are as follows:

[0023] The sliding sleeve opening tool described in this invention can smoothly open the target sliding sleeve after passing through the deformation point of the tubing string and reliably seal the internal space, thereby ensuring smooth fracturing operations and improving the success rate of well operations with deformed tubing strings. Compared with existing tools using small-sized bridge plugs, this invention allows for adjustment of the outer diameter of the opening tool according to the sleeve deformation situation, making it suitable for a wider range of tubing strings with sleeve deformation than small-sized bridge plugs. Furthermore, it is convenient to operate and highly reliable. Attached Figure Description

[0024] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, in which:

[0025] Figure 1 The diagram shown is a structural schematic of a sliding sleeve opening tool according to an embodiment of the present invention, illustrating its initial state;

[0026] Figure 2 The diagram shown is a structural schematic of a sliding sleeve opening tool according to an embodiment of the present invention, illustrating the open state of the spring piece;

[0027] Figure 3 The diagram shown is a structural schematic of a sliding sleeve opening tool according to an embodiment of the present invention, illustrating the setting state of the rubber sleeve;

[0028] Figure 4 The diagram shown is a structural schematic of a sliding sleeve opening tool according to an embodiment of the present invention, illustrating the state of the tool being released from the hand.

[0029] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not drawn to scale.

[0030] The meanings of the reference numerals in the attached drawings are as follows: 1. Spring mechanism, 2. Expandable rubber sleeve, 3. Release connector, 4. Lower connector, 5. Opening device, 11. Spring, 12. Central stopper rod, 13. Spring limiting ring, 14. Second pin, 15. C-ring, 16. Ring groove, 17. Third sealing ring, 18. Fourth sealing ring, 21. Upper sleeve, 22. Lower sleeve, 23. Expandable rubber sleeve, 24. Liquid inlet, 25. Ball seat, 26. First pin, 27. Slot, 28. First sealing ring, 29. Second sealing ring, 31. Elastic sheet, 32. Protruding structure, 41. Soluble ball. Detailed Implementation

[0031] To make the technical solutions and advantages of the present invention clearer, exemplary embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not an exhaustive list of all embodiments. Furthermore, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0032] Figure 1 The illustration schematically depicts a sliding sleeve opening tool according to an embodiment of the present invention, comprising a spring mechanism 1. The spring mechanism 1 expands radially under pressure differential and mechanically mates with the groove of the sliding sleeve, thereby accurately opening the target sliding sleeve. An expandable rubber sleeve 2 is provided at the upper end of the spring mechanism 1. A rubber sleeve is provided on the expandable rubber sleeve 2, which expands after opening to seal the tubing string, thus completing the segmentation and providing conditions for fracturing operations to open the sliding sleeve. A release connector 3 is provided at the upper end of the expandable rubber sleeve 2. The release connector 3 is connected to the coiled tubing and separates from the expandable rubber sleeve 2 after the expandable rubber sleeve 2 expands.

[0033] When using the sliding sleeve opening tool according to this embodiment, the tool is first inserted into the target sliding sleeve position in the wellbore. Then, the spring mechanism 1 is activated by differential pressure to align with the groove of the target sliding sleeve, achieving mechanical mating (e.g., Figure 2 (As shown). After the opening device 5 (such as a pressure ball) is engaged, the expansion rubber sleeve 2 expands and blocks the tubing string. At the same time, the continuous tubing is lifted to release the release connector 3, so that the release connector 3 separates from the expansion rubber sleeve 2, thus releasing the handle.

[0034] In one embodiment, such as Figure 1As shown, the expandable rubber sleeve 2 includes an upper sleeve 21 connected to the release connector 3 and a lower sleeve 22 connected to the spring mechanism 1. The upper sleeve 21 is a cylindrical short section, thicker than the lower sleeve 22. An expandable rubber sleeve 23 is fitted around the outside of the lower sleeve 22. The combined thickness of the lower sleeve 22 and the expandable rubber sleeve 23 matches that of the upper sleeve 21, facilitating passage through the deformation position of the tubing. In this embodiment, the lower sleeve 22 has a cylindrical structure with a liquid inlet hole 24 on its side wall, which connects to the expandable rubber sleeve 23. A ball seat 25 is provided inside the upper sleeve 21 to block the liquid inlet hole 24. After the opening device 5 is connected, the ball seat 25 moves downward to expose the liquid inlet hole 24.

[0035] In the sliding sleeve opening tool according to this embodiment, in the initial state (e.g.) Figure 1 (As shown) The ball seat 25 is fixedly connected to the upper sleeve 21 and blocks the liquid inlet hole 24. When the opening device 5 is engaged, as... Figure 3 As shown, the ball seat 25 is separated from the upper sleeve 21 and moved downwards. After moving away from the initial position, the inlet hole 24 is exposed, and the fluid in the lower sleeve 22 enters the expandable rubber sleeve 23 through the inlet hole 24, causing the expandable rubber sleeve 23 to expand and seal the tubing. In this embodiment, a one-way valve can be installed in the inlet hole 24 to prevent liquid backflow.

[0036] In one embodiment, a first pin 26 is provided between the ball seat 25 and the upper sleeve 21. In the initial state, the ball seat 25 is fixedly connected to the upper sleeve 21 by the first pin 26. A central hole for fluid flow is provided in the middle of the ball seat 25, through which the fluid providing pressure difference for the spring mechanism 1 flows. When the opening device 5 is engaged, the opening mechanism engages with the ball seat 25 and blocks the central hole, causing pressure to build up above the ball seat 25. When the pressure increases to a certain value, the first pin 26 shears off, and the ball seat 25 moves downward under the pressure.

[0037] In one embodiment, the upper end of the release connector 3 is provided with an internal thread for connecting a continuous oil pipe, and the lower end is provided with a plurality of elastic plates 31. The outer side of the bottom end of the elastic plates 31 is provided with a protruding structure 32; the inner side of the upper sleeve 21 is provided with a groove 27, and the protruding structure 32 is disposed in the groove 27.

[0038] When the ball seat 25 is in its initial position, it blocks the inner side of the elastic sheet 31, causing its protruding structure 32 to engage in the slot 27; when the ball seat 25 is removed, the inner side of the elastic sheet 31 loses support, causing the protruding structure 32 to slide out of the slot 27.

[0039] In the sliding sleeve opening tool according to this embodiment, in the initial state, as follows: Figure 1As shown, the ball seat 25 is fixed inside the upper sleeve 21 by the first pin 26, its upper end blocking the inner side of the elastic piece 31 of the release connector 3, thus connecting the release connector 3 to the upper sleeve 21; its lower end blocks the liquid inlet hole 24. When the opening device 5 is engaged, as... Figure 4 As shown, the opening device 5 is engaged with the ball seat 25, sealing the center hole of the ball seat 25. Pressure begins to build up above the ball seat 25. When the pressure reaches a level sufficient to shear the first pin 26, the first pin breaks, causing the ball seat 25 to separate from the upper sleeve 21. Under pressure, the ball seat 25 moves downward, exposing the inlet hole 24. Fluid enters the expandable rubber sleeve 23 through the inlet hole 24, causing it to expand. At the same time, the elastic plate 31 loses its support. When the continuous tubing is lifted, the elastic plate 31 slides out of its groove 27, thus releasing the handle.

[0040] In one embodiment, the spring mechanism 1 includes a plurality of springs 11 disposed at the lower end of the expandable rubber sleeve 2. The springs 11 are arranged circumferentially and can be expanded radially. A central stop rod 12 is disposed in the middle of the springs 11. The central stop rod 12 can move downward under the action of pressure difference, and pushes the springs 11 to expand radially when moving downward.

[0041] In a preferred embodiment, the spring mechanism 1 further includes a spring retaining ring 13, which, when the spring 11 is initially in a contracted state, restricts the spring 11 from being lifted and opened. When the thrust of the pressure difference on the central stopper 12 reaches a certain value, its radial thrust on the spring 11 is sufficient to shear the spring retaining ring 13, at which point the spring retaining ring 13 is sheared, causing the spring 11 to open. In this embodiment, two spring retaining rings 13 are preferably arranged at the upper and lower parts of the spring, respectively.

[0042] In one embodiment, the inner side of the bottom of the spring piece 11 is provided with an inclined surface, and the bottom of the central plug rod 12 is provided with a conical surface; the conical surface cooperates with the inclined surface to convert the axial pressure of the central plug rod 12 into radial thrust.

[0043] In one embodiment, the central plug rod 12 has a central hole in its middle and a pressure differential surface at its upper end. The fluid pressure creates a pressure difference on the pressure differential surface, thereby generating a thrust on the central plug rod 12. In this embodiment, the upper part of the central plug rod 12 is connected to the expansion sleeve 2 via a second pin 14. When the thrust of the pressure differential reaches a certain value, the second pin 14 is sheared, causing the central plug rod 12 to move downward.

[0044] In one embodiment, the upper part of the central plug rod 12 is inserted into the lower sleeve 22, and its outer wall is provided with a C-shaped ring 15 that can spring open radially. The inner side of the lower sleeve of the expandable rubber sleeve 2 is provided with an annular groove 16 that mates with the C-shaped ring 15. When the central plug rod 12 is in the initial position, the C-shaped ring 15 is in a compressed state. When the pin shears the central plug rod 12 and moves downward, when the central plug rod 12 moves to the position where it fully expands the spring piece 11, the C-shaped ring 15 is engaged in the annular groove 16, thus preventing the central plug rod 12 from springing back and avoiding the spring piece 11 from contracting.

[0045] In one embodiment, the lower end of the spring mechanism 1 is provided with a lower connector 4, and the interior of the lower connector 4 is provided with a soluble ball 41 that blocks the central hole of the lower connector 4.

[0046] In one embodiment, a plurality of sealing rings are provided on the outer wall of the ball seat 25, preferably including a first sealing ring 28 provided at the upper part and a second sealing ring 29 provided at the lower part. A third sealing ring 18 is provided on the outer side of the central plug rod 12, and a fourth sealing ring 18 is provided between the lower end of the expandable rubber sleeve 23 and the lower sleeve 22. The above-mentioned sealing rings can ensure that the sealing state is maintained when the state changes.

[0047] In one embodiment, the sliding sleeve opening tool is made of a soluble material, which can be dissolved by injecting a dissolving liquid or well flowback fluid after fracturing operations, thereby achieving wellbore unblocking.

[0048] In the above embodiments, "upper" refers to the direction closer to the wellhead, and "lower" refers to the direction farther from the wellhead.

[0049] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and / or modifications falling within the scope of the invention, and all changes and / or modifications made according to embodiments of the invention should be covered within the protection scope of the invention.

Claims

1. A sliding sleeve opening tool, characterized in that, include: The spring mechanism (1) is radially expanded under the action of pressure difference and mechanically paired with the groove of the sliding sleeve; An expandable rubber sleeve (2) disposed at the upper end of the spring mechanism (1) expands and seals the tubing after the opening device (5) is engaged; and The release connector (3) is provided at the upper end of the expansion rubber sleeve (2), and the release connector (3) separates from the expansion rubber sleeve (2) after the expansion rubber sleeve (2) expands. Wherein, after the sliding sleeve opening tool is sent into the target sliding sleeve position of the wellbore, the spring plate mechanism (1) is opened by pressure difference so that it is in contact with the groove of the sliding sleeve; after the opening device (5) is put in, the expansion rubber sleeve (2) expands and seals the tubing string and separates the release connector (3) from the expansion rubber sleeve (2) to achieve release; The spring mechanism (1) includes a plurality of springs (11) disposed at the lower end of the expansion rubber sleeve (2). The springs (11) are arranged circumferentially and can be expanded radially. A central stop rod (12) is disposed in the middle of the springs (11). When the central stop rod (12) moves downward under the action of pressure difference, it pushes the springs (11) to expand radially. The spring sheet (11) is initially provided with several spring sheet limiting rings (13) on its outer side. When the thrust of the central plug rod (12) on the spring sheet (11) reaches a certain value, the spring sheet limiting rings (13) are cut off, causing the spring sheet (11) to open. The bottom of the spring piece (11) is provided with an inclined surface, and the bottom of the central plug rod (12) is provided with a conical surface; the conical surface cooperates with the inclined surface to convert the axial pressure of the central plug rod (12) into radial thrust.

2. The sliding sleeve opening tool according to claim 1, characterized in that, The expandable rubber sleeve (2) includes an upper sleeve (21) connected to the release connector (3) and a lower sleeve (22) connected to the spring mechanism (1); the lower sleeve (22) is fitted with an expandable rubber sleeve (23), and the outer wall of the lower sleeve (22) is provided with an inlet hole (24) communicating with the expandable rubber sleeve (23). The upper sleeve (21) is provided with a ball seat (25) that blocks the liquid inlet hole (24). After the opening device (5) is connected, the ball seat (25) moves downward to expose the liquid inlet hole (24).

3. The sliding sleeve opening tool according to claim 2, characterized in that, The ball seat (25) is connected to the upper sleeve (21) by a first pin (26). The ball seat (25) has a central hole for fluid flow in the middle. The opening device (5) is engaged with the ball seat (25) to block the central hole, so that the ball seat (25) is compressed. When the pressure increases to a certain value, the first pin (26) is sheared, and the ball seat (25) moves downward under the pressure.

4. The sliding sleeve opening tool according to claim 3, characterized in that, The lower end of the release connector (3) is provided with a plurality of elastic pieces (31), and the outer side of the bottom end of the elastic pieces (31) is provided with a protruding structure (32); the inner side of the upper sleeve (21) is provided with a slot (27), and the protruding structure (32) is provided in the slot (27). In the initial position, the ball seat (25) blocks the inner side of the elastic sheet (31), causing its protruding structure (32) to engage in the slot (27); when the ball seat (25) is removed, the inner side of the elastic sheet (31) loses support, causing the protruding structure (32) to slide out of the slot (27).

5. The sliding sleeve opening tool according to claim 4, characterized in that, The center plug rod (12) has a central hole in the middle and a pressure differential surface at the upper end; and the upper part of the center plug rod (12) is connected to the expansion rubber sleeve (2) by a second pin (14).

6. The sliding sleeve opening tool according to claim 5, characterized in that, The upper outer wall of the central plug rod (12) is provided with a C-shaped ring (15) that can be opened radially, and the inner side of the lower part of the expansion sleeve (2) is provided with a ring groove (16) that cooperates with the C-shaped ring (15); when the central plug rod (12) moves to the position of fully opening the spring piece (11), the C-shaped ring (15) is engaged in the ring groove (16).

7. The sliding sleeve opening tool according to any one of claims 1 to 6, characterized in that, The sliding sleeve opening tool is made of a soluble material, which can be dissolved by injecting a dissolving liquid or well flowback fluid after fracturing operations, thereby achieving wellbore unblocking.

Images