Reversibly switchable sliding sleeve device

Abstract

A repeatedly switchable sliding sleeve device includes: a sliding sleeve body comprising a housing, a switch sleeve made of magnetic material disposed within the housing, and a first magnet unit and a second magnet unit respectively disposed upstream and downstream of the switch sleeve, with a pressure relief hole provided on the housing; and a switching tool including a protective housing, an electromagnet unit disposed within the protective housing, and a cable for powering the electromagnet unit. The first magnet unit is configured to apply a magnetic attraction force to the switch sleeve, causing the switch sleeve to be in a first position blocking the pressure relief hole. The switching tool is configured to be lowered into the sliding sleeve body and apply a magnetic attraction force to the switch sleeve via the electromagnet unit, causing the switch sleeve to overcome the magnetic attraction force of the first magnet unit and be attracted by the second magnet unit as the switching tool moves downwards, causing the switch sleeve to be in a second position releasing the pressure relief hole.

Description

Technical Field

[0001] This invention relates to downhole tool technology for cemented well completion, and more specifically to a repeatedly opening and closing sliding sleeve device based on magnetic attraction technology. Background Technology

[0002] Sliding sleeve devices are commonly used tools in cementing completion processes. Depending on the process requirements, the sliding sleeve of the device usually needs to be able to open and close repeatedly.

[0003] Currently, reusable sliding sleeves typically employ either mechanical or electronic control methods for opening and closing. In mechanically operated reusable sliding sleeves, a switching tool is fed into the corresponding sleeve via a continuous tube. A pressure mechanism then opens and grips the sleeve, allowing it to be opened and closed by lifting and lowering it. However, this method has the disadvantage of being slow in feeding the tool through the continuous tube, resulting in a longer operation time.

[0004] In electrically controlled, repeatedly opening and closing sliding sleeves, control commands are primarily transmitted wirelessly via RFID or pressure waves. The downhole sliding sleeve has a built-in receiving system that, upon receiving the control commands, executes them through a mechanical mechanism or hydraulic system to open and close the sleeve. However, this method has the disadvantage of being complex in both the downhole receiving and execution systems, resulting in higher costs.

[0005] Therefore, there is an urgent need for a sliding sleeve device that is simple in structure, highly reliable, and can be repeatedly switched on and off. Summary of the Invention

[0006] To address the technical problems described above, this invention aims to provide a repeatedly opening and closing sliding sleeve device based on magnetic attraction technology. This device has a simple structure and can reliably realize the repeated opening and closing of the sliding sleeve.

[0007] According to the present invention, a sliding sleeve device is provided, comprising: a sliding sleeve body including a cylindrical outer shell, a switch sleeve made of magnetic material disposed within the outer shell, and a first magnet unit and a second magnet unit respectively disposed upstream and downstream of the switch sleeve, wherein a pressure relief hole is provided on the outer shell; and a switching tool including a protective housing, an electromagnet unit disposed within the protective housing, and a cable for powering the electromagnet unit. The first magnet unit is configured to apply a magnetic attraction force to the switch sleeve, causing the switch sleeve to be in a first position blocking the pressure relief hole, resulting in the sliding sleeve device being in a closed state. The switching tool is configured to be lowered into the sliding sleeve body and apply a magnetic attraction force to the switch sleeve via the electromagnet unit, causing the switch sleeve to overcome the magnetic attraction force of the first magnet unit and be attracted by the second magnet unit as the switching tool moves downwards, causing the switch sleeve to be in a second position releasing the pressure relief hole, thereby opening the sliding sleeve device.

[0008] In one embodiment, the first magnet unit includes a first magnet and a first shielding layer, wherein the first shielding layer is configured to cover all surfaces of the first magnet except for the lower end face facing the switch sleeve.

[0009] In one embodiment, the second magnet unit includes a second magnet and a second shielding layer, wherein the second shielding layer is configured to cover all surfaces of the second magnet except for the upper end face facing the switch sleeve.

[0010] In one embodiment, the housing includes an upper housing portion and a lower housing portion fixedly connected together, wherein the first magnet unit and the second magnet unit are respectively located within the upper housing portion and the lower housing portion.

[0011] In one embodiment, the length of the first shielding layer is set to cover the length of the first magnet, and the length of the second shielding layer is set to cover the length of the second magnet and the axial movement distance of the switch sleeve.

[0012] In one embodiment, the inner surface of the sliding sleeve body has two steps, which are used to install the first magnet and the second magnet, respectively.

[0013] In one embodiment, the protective housing is made of a non-magnetic material.

[0014] In one embodiment, several sets of electromagnet units are provided inside the protective housing, and adjacent sets of electromagnet units are separated by an isolation ring.

[0015] In one embodiment, the switching tool further includes an upper plug and a lower guide head respectively disposed at its upper and lower ends, and a straightening ring is provided on both the upper plug and the lower guide head. The cable passes through the upper plug and is connected to the electromagnet unit.

[0016] In one embodiment, the switching tool is pumped into the sliding sleeve body along with the downhole fluid.

[0017] The sliding sleeve device according to the present invention can open and close the sliding sleeve body by magnetic attraction, and its structure is simple, reliable, and economical. Furthermore, the switching tool for the sliding sleeve device can be pumped down into the sliding sleeve body along with the downhole fluid. Compared to conventional coiled tubing downhole methods, this significantly reduces operation time. Attached Figure Description

[0018] The invention will now be described with reference to the accompanying drawings. In the drawings:

[0019] Figure 1 The schematic diagram illustrates the overall structure of the sliding sleeve body in the sliding sleeve device according to the present invention;

[0020] Figure 2 The schematic diagram illustrates the overall structure of the switching tool in the sliding sleeve device according to the present invention;

[0021] Figure 3 Schematic representation Figure 2 The switch tool shown is inserted into Figure 1 The sliding sleeve body shown is in the closed state, but the sliding sleeve device is still in the closed state.

[0022] Figure 4 Schematic representation Figure 2 The switch tool shown is inserted into Figure 1 The slide body shown is in the state where the slide device is already open.

[0023] In this application, all accompanying drawings are schematic and are used only to illustrate the principles of the invention, and are not drawn to scale. In all drawings, the same reference numerals are used to denote the same parts or structures. Detailed Implementation

[0024] The present invention will now be described with reference to the accompanying drawings. For ease of understanding, in this application, the direction near the wellhead is defined as upper end, upstream, or similar terms, while the direction away from the wellhead is defined as lower end, downstream, or similar terms; at the same time, the direction along the length of the sliding sleeve device is referred to as longitudinal direction, axial direction, or similar terms, while the direction perpendicular to it is referred to as transverse direction, radial direction, or similar terms.

[0025] Figure 1The overall structure of the sliding sleeve body 1 of the sliding sleeve device 100 according to the present invention is shown. Figure 1 As shown, the sliding sleeve device 100 includes a cylindrical outer shell 20, and an upper connector 10 and a lower connector 30 respectively installed at the upper and lower ends of the outer shell 20. The outer shell 20 mainly serves as a pressure-bearing protection unit and defines an inner cavity for fluid flow. The upper connector 10 is used to connect to the feed string or the previous stage sliding sleeve, while the lower connector 30 is used to connect to the next stage sliding sleeve or an isolation valve. Figure 1 In the specific embodiment shown, the outer casing 20 includes an upper outer casing portion 21 and a lower outer casing portion 22 connected together. Preferably, the upper outer casing portion 21 and the lower outer casing portion 22 are fixedly connected to each other by threads. Alternatively, the engagement of the upper and lower ends of the outer casing 20 with the upper connector 10 and the lower connector 30 can also be achieved by threaded engagement. A pressure relief hole 25 is provided on the outer wall of the outer casing 20, extending radially through the outer wall. The structure and function of the above components are well known to those skilled in the art and will not be described in detail here.

[0026] According to the present invention, a switch sleeve 35 is installed inside the housing 20. The switch sleeve 35 is made of magnetic material and is fitted inside the housing 20, thereby enabling axial movement along the inner wall of the housing 20. The switch sleeve 35 and the housing 20 are sealed by a sealing ring (not shown). Two sets of magnet units are also installed inside the sliding body 1 of the sliding sleeve device 100, located upstream and downstream of the switch sleeve 35, respectively. Stepped portions are formed on the inner surface of the sliding body 1 for mounting the two sets of magnet units, respectively. Preferably, the two sets of magnet units are located inside the upper housing portion 21 and the lower housing portion 22, respectively.

[0027] like Figure 1 As shown, the first magnet unit located upstream of the switch sleeve 35 includes a first magnet 42 and a first shielding layer 41 covering the first magnet 42. The first shielding layer 41 covers all surfaces of the first magnet 42 except for the end face (lower end face) facing the switch sleeve 35. In other words, the lower end face of the first magnet 42 facing the switch sleeve 35 is not covered by the first shielding layer 41, while all other surfaces are covered by the first shielding layer 41. Therefore, the first magnet 42 attracts the upper end face of the switch sleeve 35 to its lower end face. At this time, as... Figure 1 As shown, the switch sleeve 35 is in the first position, blocking the pressure relief hole 25, so that the pressure relief hole 25 is not connected to the inner cavity of the sliding sleeve body 1. Therefore, the sliding sleeve device 100 is in the closed state at this time.

[0028] In addition, since the other surfaces of the first magnet 42 are covered by the first shielding layer 41, the first magnet 42 can only apply magnetic force to the switch sleeve 35, without affecting the sliding sleeve device and other downhole tools.

[0029] According to the present invention, the second magnet unit downstream of the switch sleeve 35 includes a second magnet 46 and a second shielding layer 45 covering the second magnet 46. Similarly, the second shielding layer 45 covers all surfaces of the second magnet 46 except for the end face (i.e., the upper end face 26) facing the switch sleeve 35. In other words, the upper end face 26 of the second magnet 46 facing the switch sleeve 35 is not covered by the second shielding layer 45, while all other surfaces are covered by the second shielding layer 45. Thus, the second magnet 46 can attract the lower end face of the switch sleeve 35 to its upper end face. At this time, as... Figure 4 As shown, the switch sleeve 35 is in the second position where the pressure relief hole 25 has been released, allowing the pressure relief hole 25 to communicate with the inner cavity of the sliding sleeve body 1. Therefore, the sliding sleeve device 100 is in the open state at this time.

[0030] In addition, since the other surfaces of the second magnet 46 are covered by the second shielding layer 42, the second magnet 46 can only apply magnetic force to the switch sleeve 35 without affecting the sliding sleeve device and other downhole tools.

[0031] According to a preferred embodiment of the present invention, the length of the first shielding layer 41 is set to cover the length of the first magnet 42, while the length of the second shielding layer 45 is set to cover the length of the second magnet 46 and the axial movement distance of the switch sleeve 35. With this arrangement, the first shielding layer 41 and the second shielding layer 45 can achieve sufficient magnetic field shielding.

[0032] Figure 2 The schematic diagram illustrates the overall structure of the switching tool 50 of the sliding sleeve device 100 according to the present invention. For example... Figure 2 As shown, the switching tool 50 includes a hollow protective housing 60, within which are arranged a plurality of electromagnet units 65 along the axial direction. The protective housing 60 is made of a non-magnetic material, which serves both to provide pressure protection for the electromagnet units 65 inside, and to prevent interference with the magnetic field generated by the electromagnet units 65. Adjacent groups of electromagnet units 65 are separated by an isolation ring 68. The isolation ring 68 is used to adjust the spacing between the individual electromagnet units 65, facilitating magnetic attraction.

[0033] like Figure 2As shown, the switching tool 50 also includes a cable 70. The cable 70 extends through the switching tool 50 to power the electromagnet unit 70, causing it to generate magnetic attraction, thereby engaging the switching sleeve 65 in the sliding sleeve body 1. Furthermore, the switching tool 50 includes an upper plug 55 and a lower guide head 56 respectively disposed at its upper and lower ends. The lower section of the lower guide head 56 has a spherical design to facilitate the smooth insertion of the switching tool 50. An upper straightening ring 51 and a lower straightening ring 52 are respectively disposed on the upper plug 55 and the lower guide head 56. The upper straightening ring 51 and the lower straightening ring 52 are made of rubber to ensure the switching tool 50 remains centered and aligned when passing through different pipe string inner diameters during insertion. The functions and structures of these components are well known to those skilled in the art and will not be described in detail here.

[0034] The following is combined Figure 3 and 4 The working process of the sliding sleeve device 100 according to the present invention will be explained.

[0035] In its initial state, the sliding sleeve device 100 is in the closed state. That is, as... Figure 1 and 3 As shown, the lower end face of the first magnet 42 in the sliding sleeve body 1 attracts the upper end face of the switch sleeve 35 in the sliding sleeve body 1, so that the switch sleeve 35 is in the first position that blocks the pressure relief hole 25. In this case, the pressure relief hole 25 is not connected to the inner cavity of the sliding sleeve body 1.

[0036] like Figure 3 As shown, if it is necessary to open the sliding sleeve device 100, the switching tool 50 is pumped downhole to a position corresponding to the sliding sleeve body 1 of the sliding sleeve device 100. At this time, the switching tool 50 has not been activated, and the sliding sleeve device 100 remains in the closed state.

[0037] Then, power is supplied to the electromagnet unit 65 inside the switching tool 50 from the ground via cable 70. At this time, the electromagnet unit 65 generates a magnetic field, which generates an attractive force on the switch sleeve 35 through the protective housing 60.

[0038] Then, the pumping of the switching tool 50 continues downward. Due to the attraction of the electromagnet unit 65, the switching sleeve 35 is attracted to the switching tool 50 and moves downward against the attraction of the first magnet 42. As a result, the pressure relief hole 25 opens. The switching sleeve 35 eventually moves to engage with the second magnet 46, thereby maintaining the open state of the sliding sleeve body 1, as... Figure 4 As shown. Furthermore, the switch sleeve 35 is in the second position where the pressure relief hole 25 has been released, allowing the pressure relief hole 25 to communicate with the inner cavity of the sliding sleeve body 1. Therefore, the sliding sleeve device 100 is in the open state.

[0039] Finally, power is cut off from the ground control cable 70, and the magnetic force of the electromagnet unit 65 disappears. At this point, the switching tool 50 can be pulled out from downhole.

[0040] It is easy to understand that by reversing the above process, the operation of closing the sliding sleeve device 100 can be achieved.

[0041] The sliding sleeve device according to the present invention can open and close the sliding sleeve body by magnetic attraction, and its structure is simple, reliable, and economical. Furthermore, the switching tool for the sliding sleeve device can be pumped down into the sliding sleeve body along with the downhole fluid. Compared to conventional coiled tubing downhole methods, this significantly reduces operation time.

[0042] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A sliding sleeve device (100), comprising: The sliding sleeve body (1) includes a cylindrical outer shell (20), a switch sleeve (35) made of magnetic material disposed inside the outer shell (20), and a first magnet unit and a second magnet unit disposed upstream and downstream of the switch sleeve (35), respectively. A pressure relief hole (25) is provided on the outer shell (20) that extends radially through it. The switching tool (50) includes a protective housing (60), an electromagnet unit (65) disposed within the protective housing (60), and a cable (70) for supplying power to the electromagnet unit (65). The first magnet unit is configured to apply a magnetic attraction force to the switch sleeve (35) and attract the upper end face of the switch sleeve (35), so that the switch sleeve (35) is in a first position that blocks the pressure relief hole (25), causing the sliding sleeve device (100) to be in a closed state. The switching tool (50) is configured to be inserted into the sliding sleeve body (1) and to apply a magnetic attraction force to the switching sleeve (35) through the electromagnet unit (65), so that the switching sleeve (35) can overcome the magnetic attraction force of the first magnet unit and follow the insertion movement of the switching tool (50) and be attracted by the second magnet unit, so that the second magnet unit can attract the lower end face of the switching sleeve (35), so that the switching sleeve (35) is in a second position that releases the pressure relief hole (25), thereby the sliding sleeve device (100) is in the open state.

2. The sliding sleeve device (100) according to claim 1, characterized in that, The first magnet unit includes a first magnet (42) and a first shielding layer (41), wherein the first shielding layer (41) is configured to cover all surfaces of the first magnet (42) except for the lower end face facing the switch sleeve (35).

3. The sliding sleeve device (100) according to claim 2, characterized in that, The second magnet unit includes a second magnet (46) and a second shielding layer (45), wherein the second shielding layer (45) is configured to cover all surfaces of the second magnet (46) except for the upper end face facing the switch sleeve (35).

4. The sliding sleeve device (100) according to claim 3, characterized in that, The outer shell (20) includes an upper outer shell portion (21) and a lower outer shell portion (22) fixedly connected together, wherein the first magnet unit and the second magnet unit are respectively located in the upper outer shell portion (21) and the lower outer shell portion (22).

5. The sliding sleeve device (100) according to claim 4, characterized in that, The length of the first shielding layer (41) is set to cover the length of the first magnet (42), while the length of the second shielding layer (45) is set to cover the length of the second magnet (46) and the axial movement distance of the switch sleeve (35).

6. The sliding sleeve device (100) according to claim 3, characterized in that, The inner surface of the sliding sleeve body (1) has two steps, which are used to install the first magnet (42) and the second magnet (46) respectively.

7. The sliding sleeve device (100) according to any one of claims 1 to 6, characterized in that, The protective housing (60) is made of non-magnetic material.

8. The sliding sleeve device (100) according to any one of claims 1 to 6, characterized in that, Several sets of electromagnet units (65) are provided inside the protective housing (60), and two adjacent sets of electromagnet units (65) are separated by an isolation ring (68).

9. The sliding sleeve device (100) according to any one of claims 1 to 6, characterized in that, The switching tool (50) also includes an upper plug (55) and a lower guide head (56) respectively disposed at its upper and lower ends. A straightening ring is provided on both the upper plug (55) and the lower guide head (56). The cable passes through the upper plug (55) and is connected to the electromagnet unit (65).

10. The sliding sleeve device (100) according to any one of claims 1 to 6, characterized in that, The switching tool (50) is pumped into the sliding sleeve body (1) along with the downhole fluid pump.

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