Switchable sliding sleeve and control method therefor

Abstract

The present disclosure provides a switchable sliding sleeve and a control method therefor. The switchable sliding sleeve comprises: a housing assembly, wherein a plurality of fracturing channels each communicated with an external space and an inner cavity of the housing assembly are formed in the circumferential direction of the housing assembly, and an inner wall of the housing assembly is sequentially recessed in the axial direction thereof from a wellhead to a well bottom to form a closing locking slot and an opening locking slot; an inner cylinder movably passing through the inner cavity, wherein an elastic claw assembly having an expansion tendency is sleeved on the outer side of the inner cylinder and is configured to be snap-fit to the closing locking slot or the opening locking slot, and the elastic claw assembly can expand or contract in the radial direction of the housing assembly, so that the elastic claw assembly can move in the inner cavity along with the inner cylinder; and a sliding sleeve control device movably passing through the inner cavity and the interior of the inner cylinder, wherein the sliding sleeve control device drives, by means of a snap-fit assembly, the inner cylinder to move in the axial direction of the housing assembly. The switchable sliding sleeve and the control method therefor provided by the present disclosure solve the problem of low switching efficiency of switchable sliding sleeves.

Description

Switchable sliding sleeve and its control method

[0001] Related applications

[0002] This application claims priority to Chinese Patent Application No. 202411518758.4, filed on October 29, 2024, and incorporates the entire contents of the aforementioned patent application as part of this application. Technical Field

[0003] This disclosure relates to the field of downhole casing equipment technology, and in particular to a switchable sliding sleeve and its control method. Background Technology

[0004] The description in this section provides only background information in relation to this disclosure and does not constitute prior art.

[0005] With the deepening of oil and gas field development, the risk of water breakthrough during horizontal well fracturing and the problem of excessive water content during production are increasing. If water production is not controlled in time, oil and gas wells can easily become flooded, rendering oil and gas unproductive. Currently, the main methods for controlling water production in oil and gas wells are chemical agents and mechanical packers, both of which suffer from high costs and poor sealing effects. In recent years, switchable sleeve casing has gradually become the focus of water control development. Multiple switchable sleeves are connected to the casing and enter the wellbore along with the casing for cementing. Special tools are used to open the sleeves to stimulate the corresponding formations. If the water content in individual formations is too high during production, the corresponding sleeves can be closed using special tools, achieving water control development throughout the entire lifecycle of the oil and gas well. However, research on switchable sleeve casing is still in its early stages and mainly faces the following problems:

[0006] 1) The switching operation is relatively complex. The positioning and opening of the sliding sleeve require multiple lifting and lowering of the tubing, and the lifting distance and load are difficult to control.

[0007] 2) Due to the influence of cementing, the seal of the switchable sliding sleeve is prone to failure, resulting in a low success rate of the sliding sleeve switch.

[0008] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions disclosed herein, and for facilitating understanding by those skilled in the art. It should not be assumed that these technical solutions are known to those skilled in the art simply because they have been described in the background section of this disclosure. Summary of the Invention

[0009] The purpose of this disclosure is to provide a switchable sliding sleeve and its control method, which solves the problem of low switching efficiency of the switchable sliding sleeve.

[0010] The above-mentioned objectives of this disclosure are mainly achieved through the following technical solutions:

[0011] On one hand, this disclosure provides a switchable sliding sleeve, comprising:

[0012] The outer shell assembly has multiple fracturing channels circumferentially. The fracturing channels are connected to the external space and the inner cavity of the outer shell assembly respectively. The inner wall of the outer shell assembly is recessed along its own axis from the wellhead to the bottom of the well to form a closing locking groove and an opening locking groove.

[0013] The inner cylinder is movably inserted into the inner cavity along the axial direction of the outer shell assembly. An elastic claw assembly with an expanding tendency is sleeved on the outer side of the inner cylinder to engage in the closing locking groove or the opening locking groove. The elastic claw assembly can expand or contract radially along the outer shell assembly so that the elastic claw assembly can move with the inner cylinder in the inner cavity.

[0014] The sliding sleeve control device is movably installed inside the inner cavity and the inner cylinder. The sliding sleeve control device has a locking component that can lock the inner cylinder. The sliding sleeve control device can drive the inner cylinder to move along the axial direction of the outer shell assembly through the locking component.

[0015] Specifically, when the inner cylinder moves to the point where the elastic claw assembly engages in the closing locking groove, the inner cylinder blocks the fracturing channel; when the inner cylinder moves to the point where the elastic claw assembly engages in the opening locking groove, the inner cylinder releases the blockage of the fracturing channel, so that the fracturing channel is connected to the inner cavity.

[0016] In one specific embodiment, the sliding sleeve control device includes:

[0017] The central tube assembly is used to pass through the inside of the casing, inner cylinder, and inner cavity. The upper end of the central tube assembly extends from the wellhead to the bottom of the well, and the central tube assembly is provided with a track-changing element that protrudes radially outward.

[0018] A sealing assembly is sleeved on the outside of the central tube assembly. The upper end of the central tube assembly is connected to the upper end of the sealing assembly so that the central tube assembly can drive the sealing assembly to move along the axial direction of the central tube assembly. The sealing assembly includes a sealing structure that can expand radially along the central tube assembly.

[0019] The control component is movably sleeved on the central tube assembly and is located on the lower side of the sealing assembly. The control component includes a snap-fit ​​component and a long track and a short track extending along the axial direction of the central tube assembly. The snap-fit ​​component can move radially along the central tube assembly and snap onto the inner wall of the inner cylinder. The upper end of the long track is connected to the upper end of the short track. The track-changing element is movably embedded in the long track and the short track.

[0020] When the track-changing element is located at the lower end of the short track, the packer assembly and control assembly are separated, and the packer structure is in a contracted state, allowing the central tube assembly to drive the packer assembly and control assembly from the wellhead to the bottom of the well, passing through the casing and inner cylinder. As the track-changing element moves along the long track towards its lower end, the central tube assembly pushes the lower end of the packer assembly against the upper end of the control assembly, causing the packer structure to expand radially along the central tube assembly to seal the inner cylinder. The locking assembly then engages with the inner wall of the inner cylinder, sealing the inner cylinder. The pressurized liquid inside the pipe can push the sealing structure and drive the sliding sleeve control device and inner cylinder to move downward along the axis of the switchable sliding sleeve through the snap-fit ​​assembly, so as to open the switchable sliding sleeve; when the track-changing element is located at the upper end of the long track or the upper end of the short track, the snap-fit ​​assembly snaps into the inner wall of the inner cylinder, the sealing assembly and the control assembly are separated, and the sealing structure is in a contracted state, so that the central tube assembly can drive the sliding sleeve control device and inner cylinder to move upward along the axis of the switchable sliding sleeve through the snap-fit ​​assembly, so as to close the switchable sliding sleeve.

[0021] In one specific implementation,

[0022] The upper ends of the long track and the short track are aligned axially on the central tube assembly. The distance from the upper end to the lower end of the long track on the central tube assembly is greater than the distance from the upper end to the lower end of the short track on the central tube assembly.

[0023] In one specific implementation,

[0024] There are multiple long tracks and multiple short tracks. The multiple long tracks are spaced apart along the circumference of the control component, and the multiple short tracks are inserted between two adjacent long tracks. The upper end of each short track is connected to the upper end of the two adjacent long tracks.

[0025] In one specific implementation,

[0026] The upper ends of adjacent long tracks are connected to the upper ends of short tracks by a connecting channel. The connecting channel has a first connecting channel wall and a second connecting channel wall that are staggered. The first connecting channel wall is located on the side of the connecting channel near the upper end of the central tube assembly, and the second connecting channel wall is located on the side of the connecting channel near the lower end of the central tube assembly.

[0027] The first connecting wall extends to the upper end of the short track or the upper end of the long track, so that the track-changing element located at the upper end of the short track or the upper end of the long track can move upward along the first connecting wall to the upper end of the connecting track; the second connecting wall extends from the short track or the long track to the upper end of the connecting track, so that the track-changing element located at the upper end of the connecting track can move downward along the second connecting wall into the short track or the long track.

[0028] In one specific implementation,

[0029] The projection of the first connecting channel wall and the axis of the central tube assembly onto the horizontal plane forms a first included angle, which is 25° to 35°.

[0030] The projection of the second connecting channel wall and the axis of the central tube assembly onto the horizontal plane forms a second included angle, which is 25° to 35°.

[0031] In one specific implementation,

[0032] The control assembly includes a track cylinder and a sleeve. The track cylinder extends axially along the central tube assembly and is sleeved on the outside of the central tube assembly. Short tracks, long tracks, and connecting channels are all formed on the peripheral wall of the track cylinder, and the sleeve is sealed on the radial outside of the track cylinder.

[0033] In one specific implementation,

[0034] The control assembly includes a centering element connected to the lower end of the sleeve. The outer peripheral wall of the centering element has multiple first grooves. A first friction element and a first elastic element are provided in the first groove. The first elastic element is connected between the first friction element and the first groove to push the first friction element to move radially outward along the central tube assembly and abut against the inner wall of the outer shell assembly of the switch slide sleeve.

[0035] In one specific implementation,

[0036] The frictional force between the centering element and the housing assembly is 1.0 to 1.5 times the weight of the control assembly.

[0037] In one specific implementation,

[0038] The lower end of the snap-fit ​​assembly is connected to the upper end of the sleeve.

[0039] The snap-fit ​​assembly includes a positioning element, a second groove, and a push-pull element. The positioning element passes through the second groove, and the push-pull element is connected between the positioning element and the second groove to drive the positioning element to snap or separate from the inner wall of the inner cylinder along the radial direction of the central tube assembly.

[0040] In one specific implementation,

[0041] The positioning element has a first boss and a second boss protruding radially outward along the central tube assembly. The first boss and the second boss are spaced apart along the axial direction of the central tube assembly. The first boss and the second boss are respectively used to engage with the first engaging groove and the second engaging groove formed on the inner wall of the inner cylinder.

[0042] In one specific implementation,

[0043] The push-pull element includes a second elastic element connected between the positioning element and the second groove, which pushes the positioning element to move radially outward along the central tube assembly and engage with the inner wall of the inner cylinder.

[0044] In one specific implementation,

[0045] Push-pull elements also include sliding sleeve elements.

[0046] The sliding sleeve element is movably arranged along the axial direction of the central tube assembly. The end of the sliding sleeve element facing the positioning element has a sliding sleeve conical wall, and the end of the positioning element facing the sliding sleeve element has a snap-fit ​​conical wall. The sliding sleeve conical wall and the snap-fit ​​conical wall are correspondingly fitted together.

[0047] Specifically, when the sliding sleeve element moves toward the positioning element, the sliding sleeve cone wall slides upward along the engaging cone wall to push the positioning element to move radially inward along the central tube assembly; when the sliding sleeve element moves away from the positioning element, the sliding sleeve cone wall slides downward along the engaging cone wall to provide space for the positioning element to move radially outward along the central tube assembly.

[0048] In one specific implementation,

[0049] There are multiple positioning elements and multiple second grooves. The multiple second grooves are arranged at intervals along the circumference of the snap-fit ​​assembly on the outer wall of the snap-fit ​​assembly, and the multiple positioning elements are respectively inserted into the multiple second grooves.

[0050] In one specific implementation,

[0051] There are two sliding sleeve elements, which are respectively located on both sides of the positioning element along the axial direction of the central tube assembly. The sliding sleeve cone wall of the sliding sleeve element is in contact with the snap-fit ​​cone wall of the positioning element.

[0052] In one specific implementation,

[0053] The projection of the sliding sleeve cone wall and the axis of the central tube assembly onto the horizontal plane forms a third included angle, which is 20° to 25°.

[0054] The projection of the axis of the snap-fit ​​cone wall and the axis of the central tube assembly onto the horizontal plane forms a fourth included angle, which is 20° to 25°.

[0055] In one specific implementation,

[0056] The sliding sleeve component includes a sliding element, a third elastic element, and a sliding sleeve hydraulic cylinder.

[0057] The sliding sleeve is movably fitted radially outside the groove wall of the second groove along the axial direction of the central tube assembly. The sliding sleeve cone wall is formed at the end of the sliding sleeve facing the positioning element. The third elastic element is compressedly connected to the end of the sliding sleeve away from the positioning element along the axial direction of the central tube assembly to push the sliding sleeve to move closer to the positioning element. The sliding sleeve hydraulic cylinder is telescopically connected between the sliding sleeve and the groove wall of the second groove along the axial direction of the central tube assembly to push the sliding sleeve to move away from the positioning element.

[0058] In one specific implementation,

[0059] A sliding sleeve hydraulic cylinder includes a cylinder chamber, a fluid slot, a fluid delivery channel, and a fluid orifice.

[0060] A liquid slit is formed on the inner wall of the central tube assembly. A liquid delivery channel is formed between the groove wall of the second groove and the central tube assembly. A liquid hole is formed on the groove wall of the second groove. The cylinder cavity is formed by the groove wall of the second groove and the sliding sleeve. The pressurized liquid inside the central tube assembly can enter the cylinder cavity along the liquid slit, the liquid delivery channel and the liquid hole. The pressurized liquid in the cylinder cavity can push the sliding sleeve to move away from the positioning element along the axial direction of the central tube assembly.

[0061] In one specific implementation,

[0062] The central tube assembly has a ball seat inside, which is located on the side of the fluid fracture closer to the bottom of the well. The plugging ball dropped from the wellhead can plug the ball seat and guide the pressurized fluid inside the central tube assembly to the fluid fracture.

[0063] In one specific implementation,

[0064] Multiple first sealing elements are arranged in a ring between the groove wall of the second groove and the sliding sleeve. The multiple first sealing elements are respectively arranged at both ends of the cylinder cavity along the axial direction of the central tube assembly to seal the cylinder cavity. The first sealing elements are made of rubber material.

[0065] In one specific implementation,

[0066] The snap-fit ​​assembly also includes multiple second sealing elements, which are arranged around the outer periphery of the central tube assembly. The multiple second sealing elements are respectively disposed at both ends of the groove wall of the second groove along the axial direction of the central tube assembly to seal the infusion channel.

[0067] In one specific implementation,

[0068] The second sealing element includes a first sealing ring, two second sealing rings, and two third sealing rings. The two second sealing rings are respectively located at both axial ends of the first sealing ring, and the two third sealing rings are respectively located at the axial end of the second sealing ring away from the first sealing ring.

[0069] The first sealing ring is made of rubber, the second sealing ring is made of plastic, and the third sealing ring is made of metal.

[0070] In one specific implementation,

[0071] The cross-section of the first sealing ring is circular;

[0072] The second sealing ring consists of two sealing rings, one inside the other, with their adjacent ends connected. The two sealing rings are set at a certain angle to form an included angle and a sharp angle at opposite ends of the second sealing ring. The included angle of the second sealing ring is fitted into the first sealing ring.

[0073] The inner face of one side of the third sealing ring forms an angle, and the inner face of the angle fits into the sharp corner.

[0074] In one specific implementation,

[0075] The snap-fit ​​assembly also includes a slip assembly, which is connected to the upper end of the snap-fit ​​assembly;

[0076] The enclosure assembly also includes a pusher, which is connected to the lower end of the enclosure structure;

[0077] In the case where the sealing component drives the pusher to move toward the slip assembly, the front end of the pusher can pass between the slip assembly and the central tube assembly and drive the slip assembly to expand radially along the central tube assembly.

[0078] In one specific implementation,

[0079] The slip assembly includes a slip seat and slip elements connected together. The slip seat is sleeved on the central tube assembly. The slip element has multiple slips arranged circumferentially along the central tube assembly. The slips can move radially along the central tube assembly. The lower end of the pusher has a front end bevel. The inner side of the slip has a slip bevel to abut against the front end bevel.

[0080] In one specific implementation,

[0081] Multiple fourth elastic elements are compressed between the slip seat and multiple slips. The fourth elastic elements extend radially along the central tube assembly to push the multiple slips to move inward along the radial direction of the central tube assembly.

[0082] In one specific implementation,

[0083] The outer radial side of the slip is provided with multiple locking teeth, which are used to engage with the inner wall of the inner cylinder. The multiple locking teeth are continuously arranged along the axial direction of the central tube assembly.

[0084] In one specific implementation,

[0085] The lower outer side of the slip seat is covered with a dust cover. The dust cover and the outer wall of the slip seat form a compensation space. The upper end of the sliding sleeve element can fit tightly against the dust cover and move along the axial direction of the central tube assembly within the compensation space to seal the gap between the sliding sleeve element and the slip seat.

[0086] In one specific implementation,

[0087] The projection of the inclined plane of the kava and the axis of the central tube assembly onto the horizontal plane forms a fifth angle, which is 13° to 16°.

[0088] The projection of the front inclined surface and the axis of the central tube assembly onto the horizontal plane forms a sixth angle, which is 13° to 16°.

[0089] In one specific implementation,

[0090] The seventh angle is formed between the inclined surface of the tooth near the pusher and the projection of the axis of the central tube assembly on the horizontal plane, and the seventh angle is 25° to 35°.

[0091] The inclined surface of the tooth away from the pusher and the projection of the axis of the central tube assembly onto the horizontal plane form an eighth angle, which is 75° to 85°.

[0092] In one specific implementation,

[0093] The sliding sleeve control device also includes:

[0094] The volumetric cavity assembly is connected to the lower end of the central tube assembly near the bottom of the well. The volumetric cavity assembly includes an air chamber and a fluid channel located at the lower end of the assembly. The two ends of the fluid channel connect the air chamber to the outer side of the volumetric cavity assembly, respectively. A sealing plug is installed inside the fluid channel, and the sealing plug is connected to the inner wall of the fluid channel via a shear pin.

[0095] Specifically, when the pressure on the outside of the volumetric cavity assembly is greater than the shearing force of the shear pin, the sealing plug separates from the inner wall of the fluid channel, allowing the pressurized liquid in the sleeve to enter the air cavity.

[0096] In one specific implementation,

[0097] The volume of the air chamber is 1.5 to 2.5 times the volume of air compressed when the inner cylinder moves between the open and closed positions of the switch sliding sleeve.

[0098] In one specific implementation,

[0099] The shear force of the shear pin is 1.2 to 1.3 times the product of the hydrostatic pressure at the corresponding underground depth and the cross-sectional area of ​​the sealing plug.

[0100] In one specific implementation,

[0101] The elastic claw assembly includes:

[0102] Multiple first protrusions are radially outwardly projected on the outer side of the elastic claw assembly. The multiple first protrusions are circumferentially spaced along the elastic claw assembly. The first protrusions can be engaged in the closing locking groove or the opening locking groove to restrict the movement of the inner cylinder.

[0103] In one specific implementation,

[0104] One end of the elastic claw assembly is threaded to the inner cylinder, and the other end of the elastic claw assembly can move along the outer side wall of the inner cylinder so that the elastic claw assembly can expand or contract radially along the outer shell assembly.

[0105] In one specific implementation,

[0106] The elastic claw assembly also includes a second protrusion formed at the other end of the elastic claw assembly. The second protrusion protrudes radially inward along the outer shell assembly. A limiting groove is formed on the outer side wall of the inner cylinder. The second protrusion is movably embedded in the limiting groove to limit the deformation range of the elastic claw assembly.

[0107] In one specific implementation,

[0108] The step near the closing locking slot forms a first switching ramp, and the step near the opening locking slot forms a second switching ramp, so that the elastic claw assembly can retract radially along the first or second switching ramp.

[0109] The angle formed between the first switching inclined plane and the axial direction of the housing assembly is the ninth angle, which is 25° to 30°. The angle formed between the second switching inclined plane and the axial direction of the housing assembly is the tenth angle, which is 25° to 30°.

[0110] In one specific implementation,

[0111] The end face of the closing locking slot away from the opening locking slot forms a third switching slope, and the end face of the opening locking slot away from the closing locking slot forms a fourth switching slope, which is used to limit the range of movement of the elastic claw assembly in the closing locking slot or the opening locking slot.

[0112] The angle formed between the third switching inclined plane and the axial direction of the housing assembly is the eleventh angle, which is 55° to 60°. The angle formed between the fourth switching inclined plane and the axial direction of the housing assembly is the twelfth angle, which is 55° to 60°.

[0113] In one specific implementation,

[0114] The cross-section of the first protrusion is an isosceles trapezoid, and the angle formed between the side of the first protrusion and the axial direction of the inner cylinder is the thirteenth angle, which is 55° to 60°.

[0115] In one specific implementation,

[0116] An installation step is formed inside the fracturing channel. An external seal is provided on the installation step. The external seal includes an elastic baffle and a one-way element. The one-way element is used to block external fluid from entering. The elastic baffle is connected to the inner wall of the fracturing channel. The one-way element is located between the elastic baffle and the installation step to fix the one-way element inside the fracturing channel.

[0117] In one specific implementation,

[0118] The unidirectional element is a soluble sheet with two intersecting fracturing slits in the center to prevent external fluid from entering. The width of the fracturing slits is 0.1mm to 0.2mm, and the thickness of the soluble sheet is 0.4mm to 0.5mm. The soluble sheet is made of soluble magnesium alloy material.

[0119] In one specific implementation,

[0120] The aspect ratio of the fracturing channel is greater than 3.5.

[0121] In one specific implementation,

[0122] The total cross-sectional area of ​​the multiple fracturing channels is 1.1 to 1.5 times the cross-sectional area of ​​the inner cylinder.

[0123] In one specific implementation,

[0124] The inner wall of the outer casing assembly is further provided with a first step and a second step along its own axial direction, and the inner cylinder moves between the first step and the second step along the axial direction of the outer casing assembly.

[0125] When one end of the inner cylinder abuts against the first step, the elastic claw assembly is engaged in the closing locking groove; when the other end of the inner cylinder abuts against the second step, the elastic claw assembly is engaged in the opening locking groove.

[0126] In one specific implementation,

[0127] The inner wall of the inner cylinder is recessed along its own axis from the wellhead to the bottom of the well to form a first locking groove and a second locking groove. The first locking groove and the second locking groove are used to lock the first boss and the second boss formed on the outer peripheral wall of the positioning element, respectively.

[0128] In one specific implementation,

[0129] The end face of the first latching slot away from the second latching slot forms a first latching slope, and the end face of the second latching slot away from the first latching slot forms a second latching slope, so that the positioning element can slide into the first latching slot or the second latching slot along the first latching slope or the second latching slope.

[0130] The angle formed between the first clamping inclined surface and the axial direction of the inner cylinder is the fourteenth angle, which is 20° to 25°; the angle formed between the second clamping inclined surface and the axial direction of the inner cylinder is the fifteenth angle, which is 25° to 30°.

[0131] In one specific implementation,

[0132] The end face of the first latching groove near the second latching groove forms a third latching slope to confine the first protrusion within the first latching groove. The end face of the second latching groove near the first latching groove forms a fourth latching slope to confine the second protrusion within the second latching groove.

[0133] The angle formed between the third clamping inclined surface and the axial direction of the inner cylinder is the sixteenth angle, which is 80° to 85°; the angle formed between the fourth clamping inclined surface and the axial direction of the inner cylinder is the seventeenth angle, which is 80° to 85°.

[0134] In one specific implementation,

[0135] The inner wall of the outer shell assembly is also recessed with a filter groove, which is located near the second step. A felt ring is provided in the filter groove to filter the liquid between the outer shell assembly and the inner cylinder. The felt ring is composed of a mesh of felt material with a mesh count of less than 100.

[0136] In one specific implementation,

[0137] The outer casing assembly is connected to the inner cylinder by a pin, which is used to fix the relative position of the inner cylinder and the outer casing assembly during the opening and closing of the sliding sleeve. When the pressurized fluid in the casing pushes the sealing structure, the pin breaks.

[0138] On the other hand, this disclosure also provides a control method for a switchable sliding sleeve, used to open or close the aforementioned switchable sliding sleeve. The control method for the switchable sliding sleeve includes:

[0139] When the switchable sleeve needs to be opened:

[0140] Multiple switchable sliding sleeves, connected at intervals by casing, are lowered from the wellhead along the inner wall of the wellbore to the section of the wellbore to be fracturing.

[0141] Cement and cleaning fluid are injected sequentially into the inner channel of the casing to form a cement ring between the casing and the wellbore or between the switchable sliding sleeve and the wellbore.

[0142] The sliding sleeve control device, located at the lower end of the short track, moves from the wellhead along the casing channel to the side of any switchable sliding sleeve near the bottom of the well, and the switchable sliding sleeve is in the closed state.

[0143] The plugging ball moves down from the wellhead along the internal cavity of the central tube assembly to the ball seat, thereby increasing the liquid pressure in the internal cavity of the central tube assembly. The increased liquid pressure is transmitted to the cylinder cavity through the liquid gap, the liquid delivery channel, and the liquid hole in sequence, which pushes the sliding sleeve element to move away from the positioning element and causes the positioning element to expand radially along the central tube assembly.

[0144] The central tube assembly moves towards the wellhead, and the rail-changing element moves from the lower end of the short rail to the upper end of the connecting channel, driving the control assembly to move up until the positioning element is engaged with the inner wall of the inner cylinder.

[0145] The central tube assembly moves downward toward the bottom of the well, the rail-changing element moves down from the upper end of the connecting channel to the lower end of the long rail, and the central tube assembly drives the packer assembly to move down and abut against the upper end of the control assembly, causing the packer structure to expand radially along the central tube assembly to the inner cylinder of the sealing, and the slips expand radially along the central tube assembly and engage with the inner wall of the inner cylinder.

[0146] Pressurized fluid is pumped into the annulus between the casing and the sliding sleeve control device from the wellhead. The pressurized fluid can push the sealing structure and, through the positioning element and slips, drive the first protrusion connected to the inner cylinder to move down from the closed locking groove to the open locking groove, thereby releasing the blockage of the fracturing channel of the outer shell assembly by the inner cylinder, so that the fracturing channel is connected to the internal cavity of the inner cylinder, and the pressurized fluid completes the fracturing operation through the fracturing channel.

[0147] When the switchable sleeve needs to be closed:

[0148] The sliding sleeve control device located at the upper end of the connecting channel of the track-changing element moves along the casing channel to the side of any switchable sliding sleeve near the bottom of the well, and the switchable sliding sleeve is in the open state.

[0149] The plugging ball moves down from the wellhead along the internal cavity of the central tube assembly to the ball seat, thereby increasing the liquid pressure in the internal cavity of the central tube assembly. The increased liquid pressure is transmitted to the cylinder cavity through the liquid gap, the liquid delivery channel, and the liquid hole in sequence, which pushes the sliding sleeve element to move away from the positioning element and causes the positioning element to expand radially along the central tube assembly.

[0150] The central tube assembly moves towards the wellhead and drives the control assembly upward until the positioning element engages with the inner wall of the inner cylinder;

[0151] The central tube assembly continues to move closer to the wellhead, and the central tube assembly drives the first protrusion connected to the inner cylinder to move from the opening locking groove to the closing locking groove, so that the inner cylinder seals the fracturing channel.

[0152] Compared with the prior art, the technical solution disclosed herein has the following characteristics and advantages:

[0153] 1. The switchable sliding sleeve provided in this disclosure, by setting a closing locking groove and an opening locking groove, and an elastic claw assembly set on the outside of the inner cylinder, can avoid the problem that when the switchable sliding sleeve is open, that is, when the fracturing channel is prevented from connecting with the internal cavity of the inner cylinder, the inner cylinder is affected by the friction between the sliding sleeve control device and the inner cylinder, causing the inner cylinder to accidentally move to the position that blocks the fracturing channel, that is, the switchable sliding sleeve accidentally changes from the open state to the closed state; at the same time, it can also avoid the problem that when the fracturing channel is blocked by the inner cylinder, the inner cylinder is affected by the friction between the sliding sleeve control device and the inner cylinder, causing the inner cylinder to accidentally move to the position that connects the fracturing channel with the internal cavity of the inner cylinder, that is, the switchable sliding sleeve accidentally changes from the closed state to the open state.

[0154] 2. The switchable sliding sleeve provided in this disclosure, through the central tube assembly driving the track-changing element to move within the long and short tracks, can achieve switching between three states of the sliding sleeve control device: lowering state, opening state, and closing state. In the lowering state, the sliding sleeve control device as a whole does not contact the inner wall of the sleeve or the inner wall of the inner cylinder of the switchable sliding sleeve, facilitating the movement of the sliding sleeve control device within the sleeve to the position to be opened or closed. In the opening state, the sealing structure is compressed, causing it to expand and block the opening / closing mechanism. When the inner cylinder of the sliding sleeve is closed, the locking assembly also abuts against the inner cylinder of the switchable sliding sleeve. This allows the sealing structure to be pushed by the liquid pressure inside the casing, thereby moving the sliding sleeve control device towards the bottom of the well. The locking assembly then moves the inner cylinder of the switchable sliding sleeve towards the bottom of the well to open the switchable sliding sleeve and enable fracturing and other operational processes. In the closed state, the sealing structure is not compressed and retracts to its original position. The central tube assembly moves upward, and the locking assembly engages with the inner cylinder of the switchable sliding sleeve, causing the inner cylinder to move upward and thus closing the switchable sliding sleeve.

[0155] 3. The switchable sliding sleeve provided in this disclosure can switch between three states of the sliding sleeve control device and switch between the open and closed states of the switchable sliding sleeve by raising or lowering the central tube assembly, which can significantly improve the efficiency of the switchable sliding sleeve.

[0156] 4. The switchable sliding sleeve provided in this disclosure adopts a short rail and a long rail connected together so that the rail-changing element can switch freely between the long rail and the short rail. The structural design of the short rail and the long rail having different lengths results in the movement of the rail-changing element in different rails, which causes the sealing component and the control component to come into contact or separate. This ensures that ground personnel do not need to accurately grasp the lifting distance or lowering distance of the central tube component, but can realize the state switching of the sliding sleeve control device simply by lifting and lowering the action.

[0157] 5. The switchable sliding sleeve provided in this disclosure can be opened or closed in sections at the sweet spots of each oil and gas reservoir in the well. Especially when water is produced in individual sections in the later stage of production, which leads to a reduction in oil and gas production, the switchable sliding sleeve of the corresponding water-producing section can be closed to realize water-controlled development of oil and gas reservoirs.

[0158] 6. The switchable sliding sleeve control method provided in this embodiment can accurately position the inner cylinder through the sliding sleeve control device, so that the sliding sleeve control device can be stably engaged on the inner cylinder, thereby driving the inner cylinder to move downward to realize the opening of the switchable sliding sleeve, or driving the inner cylinder to move upward to realize the closing of the switchable sliding sleeve. Attached Figure Description

[0159] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this disclosure in any way. Furthermore, the shapes and scales of the components in the drawings are merely illustrative to aid in understanding this disclosure and do not specifically limit the shapes and scales of the components. Those skilled in the art, guided by the teachings of this disclosure, can select various possible shapes and scales to implement this disclosure according to specific circumstances.

[0160] Figure 1 is a schematic diagram of the sliding sleeve control device and the switchable sliding sleeve of this disclosure in the wellbore;

[0161] Figure 2 is a structural diagram of the switchable sliding sleeve of this disclosure;

[0162] Figure 3 is a cross-sectional view of the switchable sliding sleeve of this disclosure;

[0163] Figure 4 is a magnified view of a portion of position A in Figure 3;

[0164] Figure 5 is a magnified view of position B in Figure 3;

[0165] Figure 6 is a top view of position B in Figure 3;

[0166] Figure 7 is a magnified view of position C in Figure 3;

[0167] Figure 8 is a structural diagram of the sealing structure of the switchable sliding sleeve of this disclosure, and a structural diagram of the second sealing element of the sliding sleeve control device of this disclosure;

[0168] Figure 9 is a structural diagram of the elastic claw assembly of the switchable sliding sleeve of this disclosure;

[0169] Figure 10 is a front view of the elastic claw assembly of the switchable sliding sleeve of this disclosure;

[0170] Figure 11 is a structural exploded view of the sliding sleeve control device of this disclosure;

[0171] Figure 12 is a structural diagram of the track cylinder of the sliding sleeve control device of this disclosure;

[0172] Figure 13 is a structural plan view of the track cylinder of the sliding sleeve control device of this disclosure;

[0173] Figure 14 is a front view of the sliding sleeve control device of this disclosure in the "lowering state" embodiment;

[0174] Figure 15 is a front view of the sliding sleeve control device of this disclosure in the "open state" embodiment;

[0175] Figure 16 is a front view of the sliding sleeve control device of this disclosure in the "closed state" embodiment;

[0176] Figure 17 is a cross-sectional view of the upper section of the sliding sleeve control device of this disclosure in the "lowering state" embodiment;

[0177] Figure 18 is a cross-sectional view of the middle section of the sliding sleeve control device of this disclosure in the "lowering state" embodiment;

[0178] Figure 19 is a lower cross-sectional view of the sliding sleeve control device of this disclosure in the "lowering state" embodiment;

[0179] Figure 20 is a magnified view of the structure at position A in Figure 17;

[0180] Figure 21 is a cross-sectional view of the slip of the sliding sleeve control device of this disclosure;

[0181] Figure 22 is a cross-sectional view of the upper section of the sliding sleeve control device of this disclosure in the "open state" embodiment;

[0182] Figure 23 is a cross-sectional view of the middle section of the sliding sleeve control device of this disclosure in the "open state" embodiment;

[0183] Figure 24 is a lower cross-sectional view of the sliding sleeve control device of this disclosure in the "open state" embodiment;

[0184] Figure 25 is a magnified view of the structure at position A in Figure 22;

[0185] Figure 26 is a cross-sectional view of the upper section of the sliding sleeve control device of this disclosure in the "closed state" embodiment;

[0186] Figure 27 is a mid-section cross-sectional view of the sliding sleeve control device of this disclosure in the "closed state" embodiment;

[0187] Figure 28 is a lower cross-sectional view of the sliding sleeve control device of this disclosure in the "closed state" embodiment;

[0188] Figure 29 is a magnified view of the structure at position A in Figure 27;

[0189] Figure 30 is a cross-sectional view of the upper section of the sliding sleeve control device of this disclosure in an embodiment where the device is inserted into the switchable sliding sleeve of this disclosure and is in the "open state".

[0190] Figure 31 is a mid-section cross-sectional view of the sliding sleeve control device of this disclosure in an embodiment where the device is inserted into the switchable sliding sleeve of this disclosure and is in the "open state".

[0191] Figure 32 is a lower cross-sectional view of the sliding sleeve control device of this disclosure in an embodiment where the device is inserted into the switchable sliding sleeve of this disclosure and is in the "open state".

[0192] Figure 33 is a magnified view of the structure at position A in Figure 30;

[0193] Figure 34 is a magnified view of the structure at position B in Figure 30;

[0194] Figure 35 is a cross-sectional view of the upper section of the sliding sleeve control device of this disclosure in an embodiment where the device is inserted into the switchable sliding sleeve of this disclosure and is in the "closed state".

[0195] Figure 36 is a mid-section cross-sectional view of the sliding sleeve control device of this disclosure in an embodiment where the device is inserted into the switchable sliding sleeve of this disclosure and is in the "closed state".

[0196] Figure 37 is a lower cross-sectional view of the sliding sleeve control device of this disclosure in an embodiment where the device is inserted into the switchable sliding sleeve of this disclosure and is in the "closed state".

[0197] Figure 38 is a magnified view of the structure at position A in Figure 36.

[0198] Reference numerals: 100, Sliding sleeve control device; 110, Central tube assembly; 111, Rail changing element; 112, Ball seat; 120, Seal assembly; 121, Seal structure; 122, Pushing element; 123, Front bevel; 130, Control assembly; 131, Snap-fit ​​assembly; 1311, Positioning element; 1311A, First boss; 1311B, Second boss; 1312, Second groove; 1313, Push-pull element; 1313A, Second elastic element; 1313B, Sliding sleeve element; 1313C, Sliding sleeve assembly; 1313D, Third elastic element; 1313E, Sliding sleeve hydraulic cylinder; 1313F, Cylinder cavity; 1313G, Liquid slot; 1313H, Liquid delivery channel; 1313I, Liquid hole; 1314, Sliding sleeve conical wall; 1315, Snap-fit ​​conical wall; 1316. Dustproof cover; 1316A. Compensation space; 132. Long track; 133. Short track; 134. Connecting track; 1341. First connecting track wall; 1342. Second connecting track wall; 135. Track cylinder; 136. Sleeve; 137. Straightening element; 1371. First groove; 1372. First friction element; 1373. First elastic element; 138. Slip assembly; 1381. Slip seat; 1382. Slip element; 1382A. Slip; 1382B. Slip tooth; 1383. Slip inclined surface; 1384. Fourth elastic element; 140. First sealing element; 150. Second sealing element; 151. First sealing ring; 152. Second sealing ring; 153. Third sealing ring; 160. Volumetric cavity assembly; 161. Air cavity; 162. Fluid passage; 163. Sealing plug; 164. Shear pin; 200. Switchable sliding sleeve; 210. Outer shell assembly; 211. Fracturing passage; 2111. Mounting step; 212. Inner cavity; 213. Closing locking groove; 2131. First switching ramp; 2132. Third switching ramp; 214. Opening locking groove; 2141. Second switching ramp; 2142. Fourth switching ramp; 215. First step; 216. Second step; 217. Filter groove; 220. Inner cylinder; 221. Limiting groove; 222. First snap-fit ​​groove; 2221. First snap-fit ​​ramp; 2222. Third snap-fit ​​ramp; 223. Second snap-fit ​​groove; 2231. Second snap-fit ​​ramp; 2232. Fourth snap-fit ​​ramp; 230, Elastic claw assembly; 231, First protrusion; 232, Second protrusion; 240, External seal; 241, Elastic baffle; 242, One-way element; 2421, Fracturing notch; 250, Felt ring; 260, Pin; 270, Sealing structure; 271, First sealing ring; 272, Second sealing ring; 273, Third sealing ring; 300, Casing; 400, Sealing ball; 500, Wellbore; 600, Tubing; F, Axial direction of the center tube assembly; H, Radial direction of the center tube assembly. Detailed Implementation

[0199] To enable those skilled in the art to better understand the technical solutions in this disclosure, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this disclosure.

[0200] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0201] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0202] Implementation Method 1

[0203] As shown in Figures 1 to 7, this disclosure provides a switchable sliding sleeve 200, comprising:

[0204] The outer shell assembly 210 has multiple fracturing channels 211 circumferentially provided. The fracturing channels 211 are respectively connected to the external space and the inner cavity 212 of the outer shell assembly 210. The inner wall of the outer shell assembly 210 is recessed along its own axis from the wellhead to the bottom of the well to form a closing locking groove 213 and an opening locking groove 214.

[0205] The inner cylinder 220 is movably inserted into the inner cavity 212 along the axial direction of the outer shell assembly 210. An elastic claw assembly 230 with an expansion tendency is sleeved on the outer side of the inner cylinder 220 to engage in the closing locking groove 213 or the opening locking groove 214. The elastic claw assembly 230 can expand or contract radially along the outer shell assembly 210 so that the elastic claw assembly 230 can move with the inner cylinder 220 in the inner cavity 212. In some embodiments, the elastic claw assembly with an expansion tendency is an elastic finger-like structure formed by opening multiple axial through-cuts evenly distributed around the cylinder. The elastic finger-like structure has a fixed end that is fixed to the inner cylinder and a finger-like free end. The finger-like free end can have an outward expansion tendency under the elastic action of its own material.

[0206] The sliding sleeve control device 100 is movably installed inside the inner cavity 212 and the inner cylinder 220. The sliding sleeve control device has a locking component 131 that can lock the inner cylinder 220. The sliding sleeve control device 100 can drive the inner cylinder 220 to move along the axial direction of the outer shell assembly 210 through the locking component 131. The locking component 131 includes at least one radially telescopic positioning element and an elastic element that applies a radial outward force to the positioning element. The positioning element can fit into the corresponding groove on the inner wall of the inner cylinder to complete the locking and transmit the axial force.

[0207] Specifically, when the inner cylinder 220 moves to the point where the elastic claw assembly 230 engages with the closing locking groove 213, the inner cylinder 220 blocks the fracturing channel 211; when the inner cylinder 220 moves to the point where the elastic claw assembly 230 engages with the opening locking groove 214, the inner cylinder 220 releases the blockage of the fracturing channel 211, so that the fracturing channel 211 is connected to the internal cavity of the inner cylinder 220.

[0208] The switchable sleeve 200 provided in this embodiment, by providing a closing locking groove 213 and an opening locking groove 214, as well as an elastic claw assembly 230 provided on the outside of the inner cylinder 220, can avoid the problem that when the switchable sleeve 200 is open, that is, when the fracturing channel 211 is connected to the internal cavity of the inner cylinder 220, the inner cylinder 220 is accidentally moved to the position that blocks the fracturing channel 211 due to the friction between the sleeve control device 100 and the inner cylinder 220. In other words, it can prevent the switchable sleeve 200 from accidentally changing from the open state to the closed state.

[0209] The switchable sliding sleeve 200 provided in this embodiment can also avoid the problem that when the fracturing channel 211 is blocked by the inner cylinder 220, the inner cylinder 220 is affected by the friction between the sliding sleeve control device 100 and the inner cylinder 220, and the inner cylinder 220 moves accidentally to the position where the fracturing channel 211 and the inner cavity of the inner cylinder 220 are connected. In other words, the switchable sliding sleeve 200 is accidentally switched from the closed state to the open state.

[0210] In one specific embodiment, the minimum inner diameter of the outer casing assembly 210 is at least greater than the maximum inner diameter of the sleeve 300, and the minimum inner diameter of the inner cylinder 220 is at least greater than the maximum inner diameter of the sleeve 300, to ensure that the sliding sleeve control device 100 does not encounter obstruction when passing through the inner cylinder 220. In this embodiment, the maximum outer diameter of the sliding sleeve control device 100 is at least smaller than the minimum inner diameter of the sleeve 300, the minimum inner diameter of the outer shell assembly 210, and the minimum inner diameter of the inner cylinder 220, to ensure that the sliding sleeve control device 100 is not obstructed when moving within the switchable sliding sleeve 200. In one specific embodiment, the snap-fit ​​component 131 of the sliding sleeve control device 100 can be a component that can expand or contract radially along the outer shell assembly 210, or it can be a component that can expand or contract radially along the inner cylinder 220, so that the snap-fit ​​component 131 can snap onto the inner wall of the inner cylinder 220 when expanding, thereby driving the inner cylinder 220 to move axially along the outer shell assembly 210. In another embodiment, the snap-fit ​​component 131 can also be other telescopic structures or other structures that can snap onto the inner wall of the inner cylinder 220, without limitation.

[0211] As shown in Figures 1, 12 to 16, in one specific embodiment, the sliding sleeve control device 100 includes:

[0212] The central tube assembly 110 is used to pass through the casing 300, the inner cylinder 220 and the inner cavity 212. The upper end of the central tube assembly 110 extends from the wellhead to the bottom of the well, and the central tube assembly 110 is provided with a track-changing element 111 protruding outward along its own radial direction.

[0213] The sealing assembly 120 is sleeved on the outside of the central tube assembly 110. The upper end of the central tube assembly 110 is connected to the upper end of the sealing assembly 120 so that the central tube assembly 110 can drive the sealing assembly 120 to move along the axial direction F of the central tube assembly 110. The sealing assembly 120 includes a sealing structure 121, which can expand along the radial direction H of the central tube assembly 110.

[0214] The control component 130 is movably sleeved on the central tube assembly 110 and is located on the lower side of the sealing assembly 120. The control component 130 includes a snap-fit ​​component 131 and a long track 132 and a short track 133 extending along the axial direction F of the central tube assembly 110. The snap-fit ​​component 131 can move along the radial direction H of the central tube assembly 110 and snap-fit ​​onto the inner wall of the inner cylinder 220. The upper end of the long track 132 is connected to the upper end of the short track 133. The track-changing element 111 is movably embedded in the long track 132 and the short track 133. In some embodiments, the track-changing element 111 can be a cylindrical pin fixedly arranged along the radial direction of the central tube assembly 110. The two ends of the cylindrical pin cooperate with the central tube assembly 110 to embed into the long track or the short track and slide along it to achieve state switching.

[0215] When the track-changing element 111 is located at the lower end of the short track 133, the packer assembly 120 is separated from the control assembly 130, and the packer structure 121 is in a contracted state, so that the central tube assembly 110 can drive the packer assembly 120 and the control assembly 130 to pass through the casing 300 and the inner cylinder 220 from the wellhead to the bottom of the well. When the track-changing element 111 moves along the long track 132 towards the lower end of the long track 132, the central tube assembly 110 can push the lower end of the packer assembly 120 to abut against the upper end of the control assembly 130 and drive the packer structure 121 to expand radially H along the central tube assembly 110 to block the inner cylinder 220. The locking assembly 131 locks into the inner wall of the inner cylinder 220, and the sleeve... The pressurized liquid inside pipe 300 can push the sealing structure 121 and drive the sliding sleeve control device 100 and inner cylinder 220 to move downward along the axial direction of the switchable sliding sleeve 200 through the snap-fit ​​assembly 131, thereby opening the switchable sliding sleeve 200; when the track-changing element 111 is located at the upper end of the long track 132 or the upper end of the short track 133, the snap-fit ​​assembly 131 snaps into the inner wall of the inner cylinder 220, the sealing assembly 120 is separated from the control assembly 130, and the sealing structure 121 is in a contracted state, so that the central pipe assembly 110 can drive the sliding sleeve control device 100 and inner cylinder 220 to move upward along the axial direction of the switchable sliding sleeve 200 through the snap-fit ​​assembly 131, thereby closing the switchable sliding sleeve 200.

[0216] The sliding sleeve control device 100 of the switchable sliding sleeve 200 disclosed herein is movably installed inside the inner cavity 212 and the inner cylinder 220. Through the central tube assembly 110, it can drive the track-changing element 111 to move within the long track 132 and the short track 133, enabling the switching of the sliding sleeve control device 100 into three states: lowered state, open state, and closed state.

[0217] In the lowered state, the sliding sleeve control device 100 does not come into contact with the inner wall of the sleeve 300 or the inner wall of the inner cylinder 220 of the switchable sliding sleeve 200, which makes it easy for the sliding sleeve control device 100 to move within the sleeve 300 to the switchable sliding sleeve 200 to be opened or closed.

[0218] In the open state, the packer structure 121 is compressed and expands to block the inner cylinder 220 of the switchable sleeve 200. The snap-fit ​​component 131 also abuts against the inner cylinder 220 of the switchable sleeve 200. At this time, the packer structure 121 can be pushed by the liquid pressure in the casing 300, thereby driving the sleeve control device 100 to move towards the bottom of the well. The snap-fit ​​component 131 drives the inner cylinder 220 of the switchable sleeve 200 to move towards the bottom of the well together to open the switchable sleeve 200 and realize fracturing and other operations.

[0219] In the closed state, the sealing structure 121 is not compressed and retracts to its original position, the central tube assembly 110 moves upward, and the inner cylinder 220 is driven to move upward by the snap-fit ​​assembly 131 engaging with the inner cylinder 220 of the switchable sliding sleeve 200, thereby closing the switchable sliding sleeve 200.

[0220] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this disclosure can switch between three states of the sliding sleeve control device 100 and switch between the open and closed states of the switchable sliding sleeve 200 by raising or lowering the central tube assembly 110, which can significantly improve the efficiency of switching the switchable sliding sleeve 200.

[0221] The sliding sleeve control device 100 of the switchable sliding sleeve 200 disclosed herein adopts a short rail 133 and a long rail 132 connected to allow the track-changing element 111 to switch freely within the long rail 132 and the short rail 133. The structural design of the short rail 133 and the long rail 132 having different lengths results in the movement of the track-changing element 111 within different rails, causing the sealing component 120 to come into contact with or separate from the control component 130. This ensures that ground personnel do not need to precisely grasp the lifting or lowering distance of the central tube component 110, but can achieve the state switching of the sliding sleeve control device 100 simply by lifting and lowering the action.

[0222] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this disclosure can open or close the switchable sliding sleeve 200 set at the sweet spot of each oil and gas reservoir in the well in sections. Especially when water is produced in individual sections in the later stage of production, which leads to a reduction in oil and gas production, the switchable sliding sleeve 200 of the corresponding water-producing section can be closed to realize water-controlled development of oil and gas reservoirs.

[0223] In each embodiment of this document, the upper end of the central tube assembly 110 extends from the wellhead to the bottom of the well. That is, the position of the central tube assembly 110 near the wellhead is the upper end, and the position of the central tube assembly 110 near the bottom of the well is the lower end. In each embodiment, unless otherwise specified, the upper end of any other structure refers to the end of the structure near the wellhead, and the lower end of any other structure refers to the end of the structure near the bottom of the well.

[0224] Specifically, in this embodiment, the central tube assembly 110 is the power component of the sliding sleeve control device 100. The central tube assembly 110 is connected to the oil pipe 600. Ground personnel can use the oil pipe 600 to lift or lower the central tube assembly 110 to transmit force, thereby adjusting the position of the rail-changing element 111. Furthermore, the movement of the central tube assembly 110 in the "lowering state" and "closed state" can drive the control component 130 to move through the rail-changing element 111. Specifically, the movement of the central tube assembly 110 in the "lowering state" can be achieved by the rail-changing element 111 abutting against the lower end of the short rail 133 to drive the control component 130 to move towards the bottom of the well. The movement of the central tube assembly 110 in the "closed state" can be achieved by the rail-changing element 111 abutting against the upper end of the long rail 132 or the upper end of the short rail 133 to drive the control component 130 to move towards the wellhead, thereby transmitting force.

[0225] In this embodiment, the upper end of the central tube assembly 110 is connected to the upper part of the packer assembly 120, meaning that the central tube assembly 110 can drive the packer assembly 120 to move in all three states. Therefore, the central tube assembly 110 is also a connecting component of the sliding sleeve control device 100. The central tube assembly 110 connects to the tubing 600, the packer assembly 120, and the control assembly 130, which can be operated by the well operator, making them a whole. This facilitates the movement and state switching of the sliding sleeve control device 100 within the casing 300. In this embodiment, the central tube assembly 110 is threadedly connected to the tubing 600 via an upper connector.

[0226] In this embodiment, the sealing component 120 is a sealing part of the sliding sleeve control device 100. The sealing component 120 can block the internal cavity of the switchable sliding sleeve 200, so that the pressure of the liquid input into the sleeve 300 can be applied to the sliding sleeve control device 100, thereby driving the inner cylinder 220 of the switchable sliding sleeve 200 to move downward, thus opening the switchable sliding sleeve 200. In this embodiment, the sealing effect of the sealing component 120 is achieved by the sealing structure 121.

[0227] In this embodiment, the upper end of the sealing component 120 is connected to the upper end of the central tube assembly 110, and the lower end of the sealing component 120 can move along the axial direction F of the central tube assembly 110 on the outer surface of the central tube assembly 110. The sealing component 120 abuts against the upper end of the control component 130 under the drive of the central tube assembly 110. As the central tube assembly 110 continues to move downward, the control component 130 remains stationary through the snap-fit ​​component 131, and the central tube assembly 110 compresses the length of the sealing structure 121 in the axial direction of the central tube assembly 110, causing the sealing component 120 to expand outward along the radial direction H of the central tube assembly 110. In another embodiment, the lower end of the sealing component 120 can also be fixedly connected to the sealing component 120.

[0228] In this embodiment, the sealing structure 121 can be a rubber tube, corrugated tube, or other structure. The upper end of the sealing structure 121 is connected to the sealing assembly 120 via an upper pressure ring, and the lower end of the sealing structure 121 is connected to a lower pressure ring. The lower pressure ring is movably disposed on the sealing assembly 120. In another embodiment, the lower pressure ring is connected to the upper end of the control assembly 130. This is not a limitation. In this embodiment, when the lower end of the sealing assembly 120 abuts against the upper end of the control assembly 130, the lower pressure ring abuts against the upper end of the control assembly 130. The lower pressure ring is subjected to a leftward squeezing force provided by the control assembly 130, which can push the lower pressure ring to move to the position of the upper pressure ring. Therefore, the sealing structure 121 is squeezed, making the outer diameter of the sealing structure 121 larger until it is close to the inner cylinder 220 of the switchable sliding sleeve 200, thus isolating the annular space between the sealing assembly 120 and the inner cylinder 220. The pressurized liquid in the sleeve 300 can directly act on the sealing structure 121.

[0229] When the lower end of the sealing component 120 does not abut against the upper end of the control component 130, that is, when the squeezing force on the lower pressure ring disappears, the sealing structure 121 returns to its initial state under its own elastic action; in a specific embodiment, the upper end of the sealing component 120 is connected to the upper end of the central tube component 110 through the upper connecting sleeve, the upper connecting sleeve is sleeved on the outside of the central tube component 110, the upper pressure ring is threadedly connected to the upper end of the upper connecting sleeve, and the lower pressure ring can move along the axial direction of the central tube component 110 on the outer surface of the upper connecting sleeve.

[0230] In one specific embodiment, the sealing structure 121 is provided with an exhaust port and a support ring. The sealing structure 121 has a reserved compression space inside, which facilitates the outer diameter deformation of the sealing structure 121. The exhaust port is connected to the compression space, which facilitates the discharge of gas in the compression space when the sealing structure 121 deforms. The sealing structure 121 also has multiple sets of cuts on its exterior, so that the sealing assembly 120 can form multiple sets of sealing rings, which improves the sealing performance of the sealing structure 121 and also facilitates the reservation of space required for the deformation of the sealing structure 121, preventing the sealing structure 121 from being damaged by shear force.

[0231] In this embodiment, each set of cuts has a cut inside the sealing structure 121 and a cut outside the sealing structure 121. The cross-section of the cut is generally "V" shaped, and the included angle of the cut is in the range of 85° to 95°. The sealing structure 121 is provided with 2 to 4 exhaust holes, and the diameter of each exhaust hole is at least 5 mm. In a specific embodiment, the sealing structure 121 is made of rubber material, and the support ring is provided at the upper and lower ends of the sealing structure 121. The support ring is made of metal material, and the support ring and the sealing structure 121 are vulcanized into an integral structure.

[0232] In this embodiment, the control component 130 is a state switching switch component of the sliding sleeve control device 100 and a component that engages the inner cylinder 220 and drives the inner cylinder 220 to move together. In this embodiment, the engaging component 131 can move along the radial direction H of the central tube assembly 110. When the engaging component 131 moves outward along the radial direction H of the central tube assembly 110 and abuts against the inner wall of the inner cylinder 220 of the switchable sliding sleeve 200, the inner cylinder 220 can be engaged and connected to the control component 130 through the engaging component 131 to form a rigid connecting assembly that moves together.

[0233] In this embodiment, the central tube assembly 110 switches between the long track 132 and the short track 133 by the track-changing element 111 of the central tube assembly 110, so that the central tube assembly 110 drives the sealing assembly 120 to abut or separate from the control assembly 130, thereby realizing the switching of various states of the sliding sleeve control device 100.

[0234] As shown in Figures 12 and 13, in one specific embodiment,

[0235] The upper end of the long track 132 is flush with the upper end of the short track 133 on the axial direction F of the central tube assembly 110. The distance from the upper end of the long track 132 to the lower end of the long track 132 on the axial direction F of the central tube assembly 110 is greater than the distance from the upper end of the short track 133 to the lower end of the short track 133 on the axial direction F of the central tube assembly 110.

[0236] In the sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment, the length of the long track 132 is greater than the length of the short track 133. When the upper end of the long track 132 and the upper end of the short track 133 are aligned with the central tube axis, the lower end of the long track 132 is closer to the bottom of the well than the lower end of the short track 133. Therefore, when the track-changing element 111 of the central tube assembly 110 is located at the lower end of the short track 133, the sealing assembly 120 and the control assembly 130 are separated. That is, when the track-changing element 111 is located above the lower end of the short track 133 in the axial direction of the central tube assembly 110, the sealing assembly 120 and the control assembly 130 are separated.

[0237] As shown in Figures 12 and 13, in one specific embodiment,

[0238] There are multiple long tracks 132 and multiple short tracks 133. The multiple long tracks 132 are arranged at intervals along the circumference of the control component 130. The multiple short tracks 133 are respectively inserted between two adjacent long tracks 132, and the upper end of each short track 133 is connected to the upper end of the two adjacent long tracks 132.

[0239] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment, by setting multiple long rails 132 and multiple short rails 133, allows the central tube assembly 110 to rotate in any direction. The track-changing element 111 of the central tube assembly 110 can switch between the long rails 132 and the rails, realizing the switching of various states of the sliding sleeve control device 100. In this embodiment, the upper ends of the multiple long rails 132 and multiple short rails 133 are flush with and connected in the axial direction F of the central tube assembly 110. The track-changing element 111 of the central tube assembly 110 is lifted to the upper end of the long rail 132 or the upper end of the short rail 133 by lifting through the oil pipe 600. When the track-changing element 111 is located at the upper end of the long rail 132 or the upper end of the short rail 133, the track-changing element 111 can switch between the long rail 132 and the short rail 133 by rotating the central tube assembly 110.

[0240] As shown in Figures 12 and 13, in one specific embodiment,

[0241] The upper ends of adjacent long tracks 132 and short tracks 133 are connected by connecting channels 134. Connecting channels 134 have staggered first connecting channel walls 1341 and second connecting channel walls 1342. The first connecting channel wall 1341 is located on the side of connecting channel 134 near the upper end of the central tube assembly 110, and the second connecting channel wall 1342 is located on the side of connecting channel 134 near the lower end of the central tube assembly 110.

[0242] The first connecting wall 1341 extends to the upper end of the short track 133 or the upper end of the long track 132, so that the track-changing element 111 located at the upper end of the short track 133 or the upper end of the long track 132 can move upward along the first connecting wall 1341 to the upper end of the connecting track 134; the second connecting wall 1342 extends from the short track 133 or the long track 132 to the upper end of the connecting track 134, so that the track-changing element 111 located at the upper end of the connecting track 134 can move downward along the second connecting wall 1342 into the short track 133 or the long track 132.

[0243] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment, by setting a connecting channel 134 with a first connecting channel wall 1341 and a second connecting channel wall 1342, allows the track-changing element 111 to enter the connecting channel 134 by abutting against the first connecting channel wall 1341 and to enter the adjacent short track 133 or long track 132 by abutting against the second connecting channel wall 1342 when switching tracks. This improves the accuracy and convenience of track-changing element 111 and also improves the switching efficiency of the sliding sleeve control device 100 in switching states.

[0244] Specifically, in this embodiment, the first connecting wall 1341 is the abutting wall that the track-changing element 111 located at the upper end of the long track 132 or the upper end of the short track 133 abuts against when it enters the connecting channel 134. The lower end of the first connecting wall 1341 extends to the upper end of the short track 133 or the upper end of the long track 132, that is, the first connecting wall 1341 is connected to the upper end of the short track 133 or the upper end of the long track 132. In a specific embodiment, the track-changing element 111 located at the upper end of the long track 132 or the upper end of the short track 133 can slide into the connecting channel 134 from the upper end of the long track 132 or the upper end of the short track 133 abutting against the first connecting wall 1341 as the central tube assembly 110 moves.

[0245] In this embodiment, the upper end of the connecting channel 134 is positioned closer to the wellhead on the axial direction F of the central tube assembly 110, relative to the upper end of the short track 133 or the upper end of the long track 132. In this embodiment, the second connecting channel wall 1342 is the abutting wall that the track-changing element 111 located at the upper end of the connecting channel 134 abuts against when it enters another adjacent long track 132 or short track 133. The second connecting channel wall 1342 extends into the upper end of the connecting channel 134, so that the track-changing element 111 located at the upper end of the connecting channel 134 can slide into the adjacent long track 132 or short track 133 by abutting against the second connecting channel wall 1342 when it moves with the central tube assembly 110.

[0246] As shown in Figures 12 and 13, in one specific embodiment,

[0247] The projection of the axis of the first connecting channel wall 1341 and the axis of the central tube assembly 110 on the horizontal plane forms a first included angle, which is 25° to 35°.

[0248] The projection of the second connecting wall 1342 and the axis of the central tube assembly 110 onto the horizontal plane forms a second included angle, which is 25° to 35°.

[0249] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment sets the first connecting channel wall 1341 and the axis of the central tube assembly 110 at an angle, which allows the central tube assembly 110 to slide the track changing element 111 into the connecting channel 134 simply by lifting it up. At the same time, the sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment sets the second connecting channel wall 1342 and the axis of the central tube assembly 110 at an angle, which allows the central tube assembly 110 to slide the track changing element 111 into the adjacent long track 132 and short track 133 simply by lowering it down.

[0250] In this embodiment, the upper end of the connecting channel 134 is positioned closer to the wellhead on the axial direction F of the central tube assembly 110, relative to the upper end of the short track 133 or the upper end of the long track 132.

[0251] In this embodiment, the short track 133 and the long track 132 are arranged circumferentially along the central tube assembly 110. A connecting channel 134 connects the long track 132 and the short track 133. The first connecting channel wall 1341 and the second connecting channel wall 1342 of the connecting channel 134 extend circumferentially along the central tube assembly 110. The first connecting channel wall 1341 connects the upper end of the connecting channel 134 to the upper end of the upper track, or connects the upper end of the connecting channel 134 to the upper end of the short track 133. Therefore, the angle between the first connecting channel wall 1341 of the connecting channel 134 and the axis of the central tube assembly 110 needs to be measured by projecting the angle onto a plane in the same direction. Similarly, the second connecting wall 1342 connects the upper end of the connecting channel 134 to the upper track or connects the upper end of the connecting channel 134 to the short track 133. Therefore, the angle between the second connecting wall 1342 of the connecting channel 134 and the axis of the central tube assembly 110 needs to be measured by projecting them onto a plane in the same direction. In this embodiment, the first angle is the angle between the first connecting wall 1341 of the connecting channel 134 and the axis of the central tube assembly 110 projected vertically onto the horizontal plane, and the second angle is the angle between the second connecting wall 1342 of the connecting channel 134 and the axis of the central tube assembly 110 projected vertically onto the horizontal plane. In this embodiment, the first angle is any angle between 25° and 35°, and the second angle is any angle between 25° and 35°, which can reduce the moving resistance of the track-changing element 111 within the connecting channel 134.

[0252] In one specific embodiment, the track-changing element 111 located at the upper end of the long track 132 or the upper end of the short track 133 can slide from the upper end of the long track 132 or the upper end of the short track 133 against the first connecting track wall 1341 into the connecting track 134 as the central tube assembly 110 moves upward. When the track-changing element 111 located at the upper end of the connecting track 134 moves downward with the central tube assembly 110, it can slide from the connecting track 134 against the second connecting track wall 1342 into the adjacent long track 132 or short track 133.

[0253] As shown in Figures 11 to 16, in one specific embodiment...

[0254] The control assembly 130 includes a track cylinder 135 and a sleeve 136. The track cylinder 135 extends along the axial direction F of the central tube assembly 110 and is sleeved on the outer side of the central tube assembly 110. The short track 133, the long track 132, and the connecting channel 134 are all formed on the peripheral wall of the track cylinder 135. The sleeve 136 is sealed on the radial outer side of the track cylinder 135.

[0255] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment has a track cylinder 135 and a sleeve 136 coaxially assembled, with the sleeve 136 sleeved on the outside of the track cylinder 135. In a specific embodiment, the track cylinder 135 and the sleeve 136 are connected by several screws. Multiple short tracks 133, multiple long tracks 132, and multiple connecting channels 134 are all formed on the peripheral wall of the track cylinder 135.

[0256] Referring to Figures 13, 17 to 19, in one specific embodiment, when the central tube assembly 110 is in the "lowering state", the track-changing element 111 abuts against the lower end of the short track 133, driving the control assembly 130 to move towards the bottom of the well.

[0257] Referring to Figures 13, 21 to 25, and 30 to 34, in one specific embodiment, when the central tube assembly 110 changes from a "lowered state" to an "open state," the operator lifts the central tube assembly 110 via the hydraulic pipe 600, causing the track-changing element 111 to move from the lower end of the short track 133 to the upper end of the short track 133, and slides into the upper end of the connecting channel 134 by abutting against the first connecting channel wall 1341. Further, the operator lowers the central tube assembly 110 via the hydraulic pipe 600, causing the track-changing element... The component 111 slides from the upper end of the connecting channel 134 into the long track 132 by abutting against the wall 1342 of the second connecting channel. As the track-changing component 111 moves along the long track 132 to the lower end of the long track 132, the central tube assembly 110 can push the lower end of the sealing assembly 120 to abut against the upper end of the control assembly 130 and drive the sealing structure 121 to expand radially H along the central tube assembly 110 to the sealing inner cylinder 220. Then, the operator can open the switchable sliding sleeve 200 by lowering the central tube and using the snap-fit ​​assembly 131.

[0258] Referring to Figures 13, 21 to 25, and 30 to 34, in one specific embodiment, when the central tube assembly 110 changes from an "open state" to a "lowering state," the operator lifts the central tube assembly 110 via the oil pipe 600, causing the track-changing element 111 to move from the lower end of the long track 132 to the upper end of the long track 132. The sealing assembly 120 separates from the control assembly 130, and the track-changing element 111 slides into the upper end of the connecting channel 134 by abutting against the first connecting channel wall 1341. The operator continues to lower the central tube assembly 110 via the oil pipe 600, causing the track-changing element 111 to slide from the upper end of the connecting channel 134 by abutting against the second connecting channel wall 1342 into the short track 133. The operator continues to lower the central tube assembly 110, so that the track-changing element 111 can abut against the lower end of the short track 133, causing the track cylinder 135 and the sleeve 136 to move downward.

[0259] Referring to Figures 13, 26 to 29, and 35 to 38, in one specific embodiment, when the central tube assembly 110 changes from a "lowered state" to a "closed state," the operator lifts the central tube assembly 110 through the oil pipe 600, causing the track-changing element 111 to move from the lower end of the short track 133 to the upper end of the short track 133. The track-changing element 111 slides into the upper end of the connecting channel 134 by abutting against the first connecting channel wall 1341. The operator continues to lift the central tube assembly 110 through the oil pipe 600, so that the sliding sleeve control device 100 can drive the inner cylinder 220 to move upward through the snap-fit ​​assembly 131 to close the switchable sliding sleeve 200. The track-changing element 111 abuts against the upper end of the connecting channel 134 to drive the track cylinder 135 and the sleeve 136 to move upward.

[0260] Referring to Figures 13, 26 to 29, and 35 to 38, in one specific embodiment, when the central tube assembly 110 changes from a "closed state" to a "lowered state," the operator lowers the central tube assembly 110 via the oil pipe 600, causing the track-changing element 111 to slide from the upper end of the connecting channel 134 into the long track 132 by abutting against the wall 1342 of the second connecting channel. The operator then continues to raise the central tube assembly 110 via the oil pipe 600, causing the track-changing element 111 to move along the long track 132. Moved to the upper end of the long track 132, the track-changing element 111 slides into the upper end of the connecting track 134 by abutting against the first connecting track wall 1341. The operator continues to lower the central tube assembly 110 through the oil pipe 600, driving the track-changing element 111 from the upper end of the connecting track 134 to slide into the short track 133 by abutting against the second connecting track wall 1342. The operator continues to lower the central tube assembly 110, so that the track-changing element 111 can abut against the lower end of the short track 133, driving the track cylinder 135 and the sleeve 136 to move downward.

[0261] In one specific embodiment, in order to ensure that the track cylinder 135 is subjected to balanced force, there are two track-changing elements 111. The two track-changing elements 111 are symmetrically arranged on opposite sides of the central tube assembly 110. The two track-changing elements 111 are respectively embedded in the two short tracks 133 or the two long tracks 132 on opposite sides of the track cylinder 135.

[0262] As shown in Figures 11, 14 to 16, 19, 24, 32, and 37, in one specific embodiment,

[0263] The control assembly 130 includes a straightening element 137, which is connected to the lower end of the sleeve 136. The outer peripheral wall of the straightening element 137 is provided with a plurality of first grooves 1371. A first friction element 1372 and a first elastic element 1373 are provided in the first grooves 1371. The first elastic element 1373 is connected between the first friction element 1372 and the first grooves 1371, and is used to push the first friction element 1372 to move outward along the radial direction H of the central tube assembly 110 and abut against the inner wall of the outer shell assembly 210 of the switchable sliding sleeve 200.

[0264] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment, by setting a straightening element 137, can ensure that the first friction element 1372 and the upper buckle short section of the switchable sliding sleeve 200 remain relatively stationary within the friction range, and avoid relative displacement between the first friction element 1372 and the upper buckle short section when the track changing element 111 moves downward or upward.

[0265] Specifically, in this embodiment, a plurality of first grooves 1371 are spaced apart circumferentially along the straightening element 137, and a first elastic element 1373 extends radially H along the central tube assembly 110. Under the action of the first elastic element 1373, the first friction element 1372 moves outward along the radial H of the central tube assembly 110 and abuts against the inner wall of the upper clip of the switch sleeve. In a specific embodiment, back caps are provided at both ends of the first groove 1371 along the axial F of the central tube assembly 110 to limit the maximum displacement of the first friction element 1372 along the radial direction of the central tube assembly 110. In a specific embodiment, a plurality of holes are provided in the first groove 1371, and a plurality of first elastic elements 1373 are respectively disposed in the plurality of holes, and the plurality of first elastic elements 1373 are connected to the inner side of the first friction element 1372.

[0266] In one specific implementation,

[0267] The frictional force between the centering element 137 and the housing assembly 210 is 1.0 to 1.5 times the weight of the control assembly 130.

[0268] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment can avoid the relative movement of the sliding sleeve control device 100 with the switchable sliding sleeve 200 when the track changing element 111 moves due to the combined influence of gravity and downward force.

[0269] As shown in Figures 11, 14 to 16, 18, 23, 31, and 36, in one specific embodiment,

[0270] The lower end of the snap-fit ​​assembly 131 is connected to the upper end of the sleeve 136.

[0271] The snap-fit ​​assembly 131 includes a positioning element 1311, a second groove 1312, and a push-pull element 1313. The positioning element 1311 passes through the second groove 1312, and the push-pull element 1313 is connected between the positioning element 1311 and the second groove 1312 to drive the positioning element 1311 to snap or separate from the inner wall of the inner cylinder 220 along the radial direction H of the central tube assembly 110.

[0272] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment can abut against or separate from the inner wall of the inner cylinder 220 of the switchable sliding sleeve 200 by means of the positioning element 1311, so as to realize that the inner cylinder 220 is moved downward by the central tube assembly 110 to open the switchable sliding sleeve 200 or moved upward by the central tube assembly 110 to close the switchable sliding sleeve 200. In a specific embodiment, the positioning element 1311 is provided with limit rings at both ends along the axial direction F of the central tube assembly 110 to limit the maximum displacement of the positioning element 1311 in the radial direction of the central tube assembly 110. In this embodiment, the lower end of the locking component 131 is threadedly connected to the upper end of the sleeve 136 through a connecting sleeve, so that the locking component 131 can move downward together with the sleeve 136.

[0273] As shown in Figures 25, 29, and 38, in one specific embodiment,

[0274] The positioning element 1311 is provided with a first boss 1311A and a second boss 1311B protruding radially outward along the central tube assembly 110. The first boss 1311A and the second boss 1311B are spaced apart along the axial direction F of the central tube assembly 110. The first boss 1311A and the second boss 1311B are respectively used to engage the first engaging groove 222 and the second engaging groove 223 formed on the inner wall of the inner cylinder 220.

[0275] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment provides a first boss 1311A and a second boss 1311B on the outer side of the positioning element 1311 along the radial H of the central tube assembly 110. A groove is formed between the first boss 1311A and the second boss 1311B. The first boss 1311A and the second boss 1311B can be respectively engaged in the groove formed in the inner wall of the inner cylinder 220, and the inner wall of the inner cylinder 220 can also be engaged in the groove formed between the first boss 1311A and the second boss 1311B.

[0276] As shown in Figures 25, 29, and 38, in one specific embodiment,

[0277] The push-pull element 1313 includes a second elastic element 1313A, which is connected between the positioning element 1311 and the second groove 1312 to push the positioning element 1311 to move outward along the radial direction H of the central tube assembly 110 and engage with the inner wall of the inner cylinder 220.

[0278] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment has a second elastic element 1313A of the push-pull element 1313, which is a component that pushes the positioning element 1311 to move outward along the radial direction H of the central tube assembly 110. The second elastic element 1313A is compressed and connected between the positioning element 1311 and the second groove 1312 along the radial direction H of the central tube assembly 110, so as to push the positioning element 1311 to move outward along the radial direction H of the central tube assembly 110 and engage with the inner wall of the inner cylinder 220. In one specific embodiment, a plurality of holes are provided in the second groove 1312, and a plurality of second elastic elements 1313A are respectively disposed in the plurality of holes. The plurality of second elastic elements 1313A are connected to the inner side of the positioning element 1311. In an optional embodiment, the number of second elastic elements 1313A is 3 to 4. In another optional embodiment, the bottom surface of the positioning element 1311 is rectangular, and the cross-section of the inner cavity of the second groove 1312 is also rectangular. The length of the positioning element 1311 is 1.5 mm to 2 mm less than the length of the inner cavity of the second groove 1312, and the width of the positioning element 1311 is 3 mm to 5 mm less than the width of the inner cavity of the second groove 1312, so as to facilitate the movement of the positioning element 1311 in the second groove 1312.

[0279] As shown in Figures 25, 29, and 38, in one specific embodiment,

[0280] The push-pull element 1313 also includes a sliding sleeve element 1313B.

[0281] The sliding sleeve element 1313B is movable along the axial direction F of the central tube assembly 110. A sliding sleeve cone wall 1314 is formed at the end of the sliding sleeve element 1313B facing the positioning element 1311, and a snap-fit ​​cone wall 1315 is formed at the end of the positioning element 1311 facing the sliding sleeve element 1313B. The sliding sleeve cone wall 1314 and the snap-fit ​​cone wall 1315 are correspondingly fitted together.

[0282] In the state where the sliding sleeve element 1313B moves toward the positioning element 1311, the sliding sleeve cone wall 1314 slides upward along the engaging cone wall 1315 to push the positioning element 1311 to move inward along the radial direction H of the central tube assembly 110; in the state where the sliding sleeve element 1313B moves away from the positioning element 1311, the sliding sleeve cone wall 1314 slides downward along the engaging cone wall 1315 to provide space for the positioning element 1311 to move outward along the radial direction H of the central tube assembly 110.

[0283] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment has a sliding sleeve element 1313B of the push-pull element 1313 as a component that pushes the positioning element 1311 to move inward along the radial H of the central tube assembly 110. The sliding sleeve element 1313B is realized by the abutment of the sliding sleeve conical wall 1314 and the snap-fit ​​conical wall 1315.

[0284] Specifically, in this embodiment, a sliding sleeve conical wall 1314 is formed at one end of the sliding sleeve element 1313B near the positioning element 1311. The sliding sleeve conical wall 1314 is inclined in a direction away from the positioning element 1311 and close to the central tube assembly 110. The high point of the sliding sleeve conical wall 1314 is positioned close to the positioning element 1311 relative to the low point of the sliding sleeve conical wall 1314. A snap-fit ​​conical wall 1315 is formed at one end of the positioning element 1311 near the sliding sleeve element 1313B. The snap-fit ​​conical wall 1315 is inclined in a direction close to the sliding sleeve element 1313B and close to the central tube assembly 110. The high point of the snap-fit ​​conical wall 1315 is positioned away from the sliding sleeve element 1313B relative to the low point of the snap-fit ​​conical wall 1315. The angle between the snap-fit ​​conical wall 1315 and the horizontal plane is the same as the angle between the sliding sleeve conical wall 1314 and the horizontal plane, so that the sliding sleeve conical wall and the snap-fit ​​conical wall 1315 are correspondingly fitted together.

[0285] In this embodiment, when the sliding sleeve element 1313B moves towards the positioning element 1311, it slides upward along the engaging cone wall 1315 via the sliding sleeve cone wall 1314 to limit the movement range of the positioning element 1311 in the radial direction H of the central tube assembly 110, so that the sliding sleeve element 1313B can press the positioning element 1311 inward along the radial direction H of the central tube assembly 110. In this embodiment, when the sliding sleeve element 1313B moves away from the positioning element 1311, it slides downward along the engaging cone wall 1315 via the sliding sleeve cone wall 1314 to expand the movement range of the positioning element 1311 in the radial direction H of the central tube assembly 110, so that the second elastic member 1313A can push the positioning element 1311 outward along the radial direction H of the central tube assembly 110, and so that the positioning element 1311 can be engaged on the inner wall of the inner cylinder 220.

[0286] As shown in Figures 14 to 16, 25, 29, and 38, in one specific embodiment,

[0287] There are multiple positioning elements 1311 and multiple second grooves 1312. The multiple second grooves 1312 are arranged at intervals along the circumference of the snap-fit ​​assembly 131 on the outer wall of the snap-fit ​​assembly 131, and the multiple positioning elements 1311 are respectively inserted into the multiple second grooves 1312.

[0288] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment, by setting multiple positioning elements 1311 and multiple second grooves 1312, can realize the locking of the inner wall of the inner cylinder 220 by multiple positioning elements 1311, ensuring that the locking assembly 131 can stably drive the inner cylinder 220 to move downward or upward, thereby realizing the opening or closing of the switchable sliding sleeve 200.

[0289] As shown in Figures 14 to 16, 25, 29, and 38, in one specific embodiment,

[0290] There are two sliding sleeve elements 1313B, which are respectively located on both sides of the positioning element 1311 along the axial direction of the central tube assembly 110. The sliding sleeve cone wall 1314 of the sliding sleeve element 1313B is in contact with the snap-fit ​​cone wall 1315 of the positioning element 1311.

[0291] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment has two locking conical walls 1315 symmetrically formed at both ends of the positioning element 1311 along the axial direction of the central tube assembly 110. The two sliding sleeve elements 1313B are respectively disposed on both sides of the positioning element 1311 along the axial direction of the central tube assembly 110. When the two sliding sleeve elements 1313B move towards the positioning element 1311, they slide upward along the locking conical wall 1315 through the sliding sleeve conical wall 1314, pressing the positioning element 1311 inward along the radial direction H of the central tube assembly 110. When the two sliding sleeve elements 1313B move away from the positioning element 1311, they slide downward along the locking conical wall 1315 through the sliding sleeve conical wall 1314. The second elastic member 1313A can push the positioning element 1311 outward along the radial direction H of the central tube assembly 110, so that the positioning element 1311 can be locked on the inner wall of the inner cylinder 220.

[0292] As shown in Figures 25, 29, and 38, in one specific embodiment,

[0293] The projection of the axis of the sliding sleeve conical wall 1314 and the axis of the central tube assembly 110 onto the horizontal plane forms a third included angle, which is 20° to 25°.

[0294] The projection of the axis of the snap-fit ​​cone wall 1315 and the axis of the central tube assembly 110 onto the horizontal plane forms a fourth included angle, which is 20° to 25°.

[0295] The slide control device 100 of the switchable slide 200 provided in this embodiment can reduce the resistance of the slide element 1313B to push the positioning element 1311 by limiting the size of the third included angle and the size of the fourth included angle.

[0296] Specifically, in this embodiment, the third included angle is any included angle within 20° to 25°, and the fourth included angle is any included angle within 20° to 25°. In one specific embodiment, the third included angle and the fourth included angle can be the same angle to increase the contact area between the sliding sleeve cone wall 1314 and the snap-fit ​​cone wall 1315. In another embodiment, the third included angle and the fourth included angle can also be set to different angles, and there is no specific limitation on this.

[0297] As shown in Figures 25, 29, and 38, in one specific embodiment,

[0298] The sliding sleeve element 1313B includes a sliding element 1313C, a third elastic element 1313D, and a sliding sleeve hydraulic cylinder 1313E.

[0299] The sliding sleeve 1313C is movably fitted along the axial direction F of the central tube assembly 110 on the radially outer side of the groove wall of the second groove 1312. The sliding sleeve conical wall 1314 is formed at one end of the sliding sleeve 1313C facing the positioning element 1311. The third elastic member 1313D is compressedly connected along the axial direction F of the central tube assembly 110 to the end of the sliding sleeve 1313C away from the positioning element 1311, so as to push the sliding sleeve 1313C to move closer to the positioning element 1311. The sliding sleeve hydraulic cylinder 1313E is telescopically connected along the axial direction F of the central tube assembly 110 between the sliding sleeve 1313C and the groove wall of the second groove 1312, so as to push the sliding sleeve 1313C to move away from the positioning element 1311.

[0300] Specifically, in this embodiment, the sliding sleeve 1313C is generally composed of two cylindrical sections. The two cylinders are coaxial and their axes are collinear with the axis of the central tube assembly 110. The cylinder with a larger diameter is located on the side closer to the positioning element 1311, and the cylinder with a smaller diameter is located on the side farther from the positioning element 1311. In this embodiment, the sliding sleeve conical wall 1314 is formed at the end of the cylinder with a larger diameter that is closer to the positioning element 1311. In this embodiment, the third elastic member 1313D is compressed and connected along the axial direction F of the central tube assembly 110 to the end of the cylinder with a larger diameter that is farther from the positioning element 1311, so as to push the sliding sleeve 1313C to move towards the positioning element 1311.

[0301] In this embodiment, the larger diameter cylinder of the sliding sleeve 1313C opens near the end of the positioning element 1311, and the groove wall of the second groove 1312 is fitted with the larger diameter cylinder. The sliding sleeve cone wall 1314 moves along the axial direction F of the central tube assembly 110 at the opening of the second groove 1312 to abut against the snap-fit ​​cone wall 1315 of the positioning element 1311 protruding from the second groove 1312.

[0302] In this embodiment, the sliding sleeve hydraulic cylinder 1313E is disposed between the outer side of the groove wall of the second groove 1312 and the sliding assembly 1313C, for pushing the sliding assembly 1313C to move away from the positioning element 1311. In one specific embodiment, the sliding sleeve hydraulic cylinder 1313E is disposed between the outer side of the groove wall of the second groove 1312 and the larger diameter cylinder of the sliding assembly 1313C. In another specific embodiment, the sliding sleeve hydraulic cylinder 1313E is disposed between the outer side of the groove wall of the second groove 1312 and the smaller diameter cylinder of the sliding assembly 1313C.

[0303] As shown in Figures 25, 29, and 38, in one specific embodiment,

[0304] The sliding sleeve hydraulic cylinder 1313E includes a cylinder cavity 1313F, a fluid slot 1313G, a fluid delivery channel 1313H, and a fluid hole 1313I.

[0305] A liquid slit 1313G is formed on the inner wall of the central tube assembly 110. A liquid delivery channel 1313H is formed between the groove wall of the second groove 1312 and the central tube assembly 110. A liquid hole 1313I is formed on the groove wall of the second groove 1312. The cylinder cavity 1313F is formed by the groove wall of the second groove 1312 and the sliding sleeve 1313C. The pressurized liquid inside the central tube assembly 110 can enter the cylinder cavity 1313F along the liquid slit 1313G, the liquid delivery channel 1313H, and the liquid hole 1313I. The pressurized liquid in the cylinder cavity 1313F can push the sliding sleeve 1313C to move away from the positioning element 1311 along the axial direction F of the central tube assembly 110.

[0306] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment has a second groove 1312 with a groove wall protruding radially H along the central tube assembly 110 and a groove wall extending axially F along the central tube assembly 110. The diameter of the groove wall protruding radially H along the central tube assembly 110 is larger than the diameter of the groove wall extending axially F along the central tube assembly 110. In this embodiment, the liquid hole 1313I is opened on the groove wall extending axially F along the central tube assembly 110. The axis of the liquid hole 1313I extends radially H along the central tube assembly 110. In this embodiment, the infusion channel 1313H is formed between the inner side of the groove wall extending axially F along the central tube assembly 110 and the outer side of the central tube assembly 110 in the second groove 1312.

[0307] In this embodiment, the cylinder cavity 1313F is formed between the outer side of the groove wall extending along the axial direction F of the central tube assembly 110 and the inner side of the smaller diameter cylinder. The groove wall extending along the axial direction F of the central tube assembly 110 has a boss protruding outward along the radial direction H of the central tube assembly 110. The inner side of the smaller diameter cylinder has a boss protruding inward along the radial direction H of the central tube assembly 110 to form the two end sidewalls of the cylinder cavity 1313F along the axial direction F of the central tube assembly 110. In this embodiment, the pressurized liquid can push the sliding sleeve 1313C to move away from the positioning element 1311 by pushing the boss protruding on the inner side of the smaller diameter cylinder.

[0308] In this embodiment, the liquid slit 1313G extends along the axial direction F of the central tube assembly 110. The liquid slit 1313G is formed on the side wall of the central tube assembly 110 and connects the internal cavity and the outside of the central tube assembly 110. Pressurized liquid can flow from the inside of the central tube assembly 110 to the outside of the central tube assembly 110 through the liquid slit 1313G. In this embodiment, pressurized liquid can flow from the inside of the central tube assembly 110 to the infusion channel 1313H through the liquid slit 1313G. In a specific embodiment, there are multiple liquid slits 1313G, which are spaced apart circumferentially along the central tube assembly 110. In this embodiment, in order to quickly transfer pressurized liquid to the infusion channel 1313H while ensuring the tensile strength of the central tube assembly 110, the number of liquid slits 1313G can be selected as 12 to 15. In this embodiment, to prevent impurities from entering the cut, the width of the liquid cut 1313G of the central tube assembly 110 may be 0.1mm to 0.2mm.

[0309] In one specific embodiment, when the pressure of the pressure fluid inside the central tube assembly 110 increases, the pressure fluid in the cylinder cavity 1313F can push the sliding sleeve 1313C to move away from the positioning element 1311 along the axial direction F of the central tube assembly 110. When the pressure of the pressure fluid inside the central tube assembly 110 decreases, the third elastic element 1313D pushes the sliding sleeve 1313C to move closer to the positioning element 1311 along the axial direction F of the central tube assembly 110, so as to achieve the movement effect of the sliding sleeve element 1313B.

[0310] As shown in Figures 18, 23, 27, 31, and 36, in one specific embodiment,

[0311] The center tube assembly 110 has a ball seat 112 inside. The ball seat 112 is located on the side of the liquid fracture 1313G that is close to the bottom of the well. The plugging ball 400 dropped from the wellhead can plug the ball seat 112 and guide the pressurized liquid inside the center tube assembly 110 to flow to the liquid fracture 1313G.

[0312] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment provides a ball seat 112 inside the central tube assembly 110, that is, inside the internal cavity of the central tube assembly 110, to seal the internal cavity of the central tube assembly 110. Specifically, in this embodiment, the upper end of the ball seat 112 is formed with a conical surface to receive the sealing ball 400, and to facilitate the sealing ball 400 to fit against the conical surface of the ball seat 112 to seal the internal cavity of the central tube assembly 110, and to ensure that the sealing ball 400 will not get stuck in the ball seat 112. In an optional embodiment, the included angle between the conical surface of the ball seat 112 and the axis of the ball seat 112 is 12° to 15°.

[0313] As shown in Figures 25, 29, and 38, in one specific embodiment,

[0314] A plurality of first sealing elements 140 are provided in a ring between the groove wall of the second groove 1312 and the sliding assembly 1313C. The plurality of first sealing elements 140 are respectively disposed at both ends of the cylinder cavity 1313F along the axial direction of the central tube assembly 110 to seal the cylinder cavity 1313F. The first sealing elements 140 are made of rubber material.

[0315] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment can ensure that no pressurized fluid leakage occurs when the cylinder cavity 1313F expands or contracts by employing a first sealing element 140. In this embodiment, the first sealing element 140 is generally an "O"-shaped sealing ring, and the optional material of the first sealing element 140 is hydrogenated nitrile.

[0316] As shown in Figures 17 and 22, in one specific embodiment,

[0317] The snap-fit ​​assembly 131 also includes a plurality of second sealing elements 150. The second sealing elements 150 are arranged around the outer periphery of the central tube assembly 110. The plurality of second sealing elements 150 are respectively disposed at both ends of the groove wall of the second groove 1312 along the axial direction of the central tube assembly 110, for sealing the infusion channel 1313H.

[0318] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment can seal both ends of the infusion channel 1313H by circumferentially providing a second sealing element 150 at both ends of the groove wall of the second groove 1312 along the axial direction of the central tube assembly 110, thereby preventing the pressurized liquid in the infusion channel 1313H from leaking from the inner side of the groove wall of the second groove 1312 or the outer side of the radial direction H of the central tube assembly 110. Specifically, in this embodiment, the infusion channel 1313H is located between the inner side of the groove wall of the second groove 1312 extending along the axial direction F of the central tube assembly 110 and the outer side of the central tube assembly 110, and the second sealing element 150 circumferentially provides and seals both ends of the groove wall of the second groove 1312 extending along the axial direction F of the central tube assembly 110.

[0319] As shown in Figures 8, 17, and 22, in one specific embodiment,

[0320] The second sealing element 150 includes a first sealing ring 151, two second sealing rings 152, and two third sealing rings 153. The two second sealing rings 152 are respectively disposed at both axial ends of the first sealing ring 151, and the two third sealing rings 153 are respectively disposed at one axial end of the second sealing ring 152 away from the first sealing ring 151.

[0321] The first sealing ring 151 is made of rubber, the second sealing ring 152 is made of plastic, and the third sealing ring 153 is made of metal.

[0322] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment uses a three-layer sealing ring structure to seal the infusion channel 1313H, which undertakes the functions of pressurized liquid flow and pressure transmission, thereby improving the sealing performance of the infusion channel 1313H. Among them, the third sealing ring 153 serves as a supporting frame, and the second sealing ring 152, made of plastic material, undertakes the function of compressing the first sealing ring 151 made of rubber and connecting the third sealing ring 153, which can ensure the sealing effect of the infusion channel 1313H when the central tube assembly 110 moves.

[0323] In a specific embodiment, the first sealing ring 151, the second sealing ring 152, and the third sealing ring 153 are all generally "O-ring" sealing ring structures. The first sealing ring 151 may be made of hydrogenated nitrile material, the second sealing ring 152 may be made of polytetrafluoroethylene material, and the third sealing ring 153 may be made of copper material.

[0324] As shown in Figures 8, 17, and 22, in one specific embodiment,

[0325] The cross-section of the first sealing ring 151 is circular;

[0326] The second sealing ring 152 is composed of two sealing rings, one inner and one outer, with adjacent ends connected and the two sealing rings arranged at a certain angle to form an included angle and a sharp angle at opposite ends of the second sealing ring 152. The included angle of the second sealing ring 152 is fitted with the first sealing ring 151.

[0327] The third sealing ring 153 forms an inside angle on one side end face, and the inside of the inside angle is fitted with the sharp corner.

[0328] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment can effectively seal the infusion channel 1313H between the outer side of the central tube assembly 110 and the inner side of the second groove 1312 by means of the second sealing element 150 formed by the first sealing ring 151, the second sealing ring 152 and the third sealing ring 153.

[0329] Specifically, in this embodiment, the first sealing ring 151 is a circular sealing ring, and the second sealing ring 152 has a generally zigzag cross-section, that is, it is composed of inner and outer sealing rings that are nested and connected to each other. One sealing ring of the second sealing ring 152 is inclined in one direction, and the other sealing ring of the second sealing ring 152 is inclined in another direction to form a "slanted zigzag" structure. In this embodiment, the second sealing ring 152 has an included angle portion and a pointed corner portion. The included angle portion of the second sealing ring 152 is used to snap onto the rubber-made first sealing ring 151. The pointed corner portion of the second sealing ring 152 is set towards the inside of the included angle of the third sealing ring 153, so that the inside of the included angle of the third sealing ring 153 can clamp the pointed corner portion of the second sealing ring 152, achieving a tight seal and improving the sealing effect of the second sealing element 150.

[0330] As shown in Figures 14 to 17, 20 to 22, 26, 30, 33, and 35, in one specific embodiment,

[0331] The snap-fit ​​assembly 131 also includes a slip assembly 138, which is connected to the upper end of the snap-fit ​​assembly 131;

[0332] The enclosure assembly 120 also includes a pusher 122, which is connected to the lower end of the enclosure structure 121;

[0333] In the state where the sealing component 120 drives the pusher 122 to move toward the slip component 138, the front end of the pusher 122 can pass through the slip component 138 and the central tube component 110 and drive the slip component 138 to expand along the radial H of the central tube component 110.

[0334] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment has a slip component 138 that is threadedly connected to the upper end of the snap-fit ​​component 131. The slip component 138 is a component in the sliding sleeve control device 100 that snaps and locks the inner wall of the inner cylinder 220.

[0335] Specifically, in this embodiment, the pusher 122 is disposed at the lower end of the sealing assembly 120, and the upper end of the pusher 122 is connected to the lower end of the sealing assembly 120. In a specific embodiment, when the central tube assembly 110 moves downward, the lower pressure ring of the sealing structure 121 abuts against the upper end of the pusher 122. The lower pressure ring is subjected to a leftward squeezing force provided by the upper end of the pusher 122, which can push the lower pressure ring to move to the position of the upper pressure ring, thus squeezing the sealing structure 121, making the outer diameter of the sealing structure 121 larger until it is close to the inner cylinder 220 of the switchable sliding sleeve 200.

[0336] In this embodiment, the pusher 122 is generally conical in shape and is sleeved on the outside of the central tube assembly 110. The slip assembly 138 has a conical opening. When the pusher 122 moves downward with the central tube assembly 110, the front end of the pusher 122 is inserted into the opening of the slip assembly 138, that is, the front end of the pusher 122 passes between the slip assembly 138 and the central tube assembly 110. When the front end of the pusher 122 continues to move downward, the front end of the pusher 122 can squeeze the slip assembly 138 so that the slip assembly 138 expands outward along the radial direction H of the central tube assembly 110.

[0337] In this embodiment, when the sliding sleeve control device 100 changes from the "lowering state" to the "open state", that is, when the track changing element 111 moves along the long track 132 to the lower end of the long track 132, the central tube assembly 110 can push the pusher 122 at the lower end of the sealing assembly 120 to abut against the slip assembly 138 at the upper end of the control assembly 130. The front end of the pusher 122 can squeeze the slip assembly 138 so that the slip assembly 138 expands outward along the radial direction H of the central tube assembly 110. When the sliding sleeve control device 100 is in the "closed state", the track changing element 111 is located at the lower end of the short track 133, and the pusher 122 is separated from the slip assembly 138.

[0338] As shown in Figures 14 to 17, 20 to 22, 26, 30, 33, and 35, in one specific embodiment,

[0339] The slip assembly 138 includes a slip seat 1381 and a slip element 1382 connected to each other. The slip seat 1381 is sleeved on the central tube assembly 110. The slip element 1382 has a plurality of slips 1382A arranged circumferentially along the central tube assembly 110. The slips 1382A can move radially H along the central tube assembly 110. The lower end of the pusher 122 has a front end slope 123. The inner side of the slip 1382A is provided with a slip slope 1383 to abut against the front end slope 123.

[0340] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment has multiple slips 1382A with inner slip bevels 1383 forming the opening of the slip assembly 138. The front bevel 123 of the lower end of the cone-shaped pusher 122 forms the cone structure of the pusher 122. The pusher 122 is fitted to the slip bevels 1383. When the pusher 122 moves downward along the axial direction F of the central tube assembly 110, the front bevel 123 of the pusher 122 abuts against the slip bevel 1383 of the slip 1382A. The front bevel 123 moves downward along the slip bevel 1383 to push the slip 1382A to expand outward along the radial direction H of the central tube assembly 110, so that the slip 1382A can abut against the inner wall of the inner cylinder 220. In a specific embodiment, the number of slips 1382A can be selected as 4 or 5, and there is no limitation on this.

[0341] As shown in Figures 14 to 17, 20 to 22, 26, 30, 33, and 35, in one specific embodiment,

[0342] Multiple fourth elastic members 1384 are compressed between the slip seat 1381 and multiple slips 1382A. The fourth elastic members 1384 extend radially H along the central tube assembly 110 to push the multiple slips 1382A to move inward along the radial H of the central tube assembly 110.

[0343] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment, by providing a fourth elastic element 1384, can compress and reset the expanded slip 1382A inward along the radial H of the central tube assembly 110, thereby avoiding abnormal state switching of the central tube assembly 110 caused by the slip 1382A failing to reset when the sliding sleeve control device 100 changes from "open state" to "closed state".

[0344] Specifically, in this embodiment, the lower end of the slip 1382A protrudes downward along the axial direction F of the central tube assembly 110, and the upper end of the slip seat 1381 protrudes upward along the axial direction F of the central tube assembly 110, with the slip plate of the slip 1382A and the slip seat 1381 overlapping in the radial direction H of the central tube assembly 110. The slip plate of the slip 1382A is closer to the central tube assembly 110 than the slip seat 1381, and a space is formed between the slip plate of the slip 1382A and the slip seat 1381. In this embodiment, the fourth elastic member 1384 is disposed between the slip plate of the slip 1382A and the slip seat 1381 to push the slip 1382A to move inward along the radial direction H of the central tube assembly 110.

[0345] As shown in Figures 14 to 17, 20 to 22, 26, 30, 33, and 35, in one specific embodiment,

[0346] The outer radial side of the slip 1382A is provided with a plurality of teeth 1382B, which are used to engage with the inner wall of the inner cylinder 220. The plurality of teeth 1382B are continuously arranged along the axial direction F of the central tube assembly 110.

[0347] In the slide control device 100 of the switchable slide 200 provided in this embodiment, the locking teeth 1382B can engage with the inner wall of the inner cylinder 220 of the switchable slide 200.

[0348] As shown in Figures 14 to 17, 20 to 22, 26, 30, 33, and 35, in one specific embodiment,

[0349] The inclined surface of the tooth 1382B near the pusher 122 forms a seventh angle with the projection of the axis of the central tube assembly 110 on the horizontal plane. The seventh angle is any angle between 25° and 35°.

[0350] The inclined surface of the tooth 1382B on the side away from the pusher 122 forms an eighth angle with the projection of the axis of the central tube assembly 110 on the horizontal plane. The eighth angle is any angle between 75° and 85°.

[0351] The slide control device 100 of the switchable slide 200 provided in this embodiment can make the locking teeth 1382B more stably engage with the inner wall of the inner cylinder 220 by limiting the angle of the locking teeth 1382B.

[0352] As shown in Figures 25, 29, and 38, in one specific embodiment,

[0353] The lower outer side of the slip seat 1381 is covered with a dust cover 1316. The dust cover 1316 and the outer wall of the slip seat 1381 form a compensation space 1316A. The upper end of the sliding sleeve element 1313B can be tightly attached to the dust cover 1316 and move along the axial direction F of the central tube assembly 110 within the compensation space 1316A to seal the gap between the sliding sleeve element 1313B and the slip seat 1381.

[0354] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment, by providing a dustproof cover 1316, can ensure that no mechanical impurities enter the compensation space 1316A, so that the sliding sleeve element 1313B will not be obstructed when sliding into the compensation space 1316A, thereby improving the stability of the snap-fit ​​component 131 of the sliding sleeve control device 100 in the snap-fit ​​or retraction process and avoiding the risk of obstruction of state switching.

[0355] Specifically, in this embodiment, the lower end of the slip seat 1381 protrudes downward along the axial direction F of the central tube assembly 110 with a plate. A dust cover 1316 covers the outside of the plate of the slip seat 1381. A compensation space 1316A is formed between the dust cover 1316 and the outside of the plate of the slip seat 1381. An opening is formed between the dust cover 1316 and the plate of the slip seat 1381, and the opening is located in the compensation space 1316A facing the sliding sleeve element. On one side of 1313B, in one specific embodiment, the smaller diameter cylinder of the sliding kit 1313C extends from the opening of the compensation space 1316A into the compensation space 1316A. The inner wall of the sliding kit 1313C abuts against the plate of the slip seat 1381, and the outer wall of the sliding kit 1313C abuts against the inner side of the dust cover 1316 to block the opening of the compensation space 1316A and prevent mechanical impurities from entering the compensation space 1316A.

[0356] As shown in Figures 14 to 17, 20 to 22, 26, 30, 33, and 35, in one specific embodiment,

[0357] The projection of the inclined plane 1383 of the clasp and the axis of the central tube assembly 110 onto the horizontal plane forms a fifth angle, which is 13° to 16°.

[0358] The projection of the front inclined surface 123 and the axis of the central tube assembly 110 onto the horizontal plane forms a sixth angle, which is 13° to 16°.

[0359] The slide control device 100 of the switchable slide 200 provided in this embodiment can reduce the resistance of the pusher 122 in pushing the slip 1382A by limiting the size of the fifth included angle and the size of the sixth included angle.

[0360] Specifically, in this embodiment, the fifth included angle is any included angle within the range of 13° to 16°, and the sixth included angle is any included angle within the range of 13° to 16°. In one specific embodiment, the fifth included angle and the sixth included angle can be the same angle to increase the contact area between the front end inclined surface 123 and the cladding inclined surface 1383. In another embodiment, the fifth included angle and the sixth included angle can also be set to different angles, and there is no specific limitation on this.

[0361] As shown in Figures 11, 14 to 16, 19, 24, 28, 32, and 37, in one specific embodiment,

[0362] The sliding sleeve control device 100 also includes:

[0363] The volumetric cavity assembly 160 is connected to the lower end of the central tube assembly 110 near the bottom of the well. The volumetric cavity assembly 160 includes an air cavity 161 and a fluid channel 162 formed at the lower end of the volumetric cavity assembly 160. The two ends of the fluid channel 162 are respectively connected to the outer sides of the air cavity 161 and the volumetric cavity assembly 160. A sealing plug 163 is provided inside the fluid channel 162, and the sealing plug 163 is connected to the inner wall of the fluid channel 162 via a shear pin 164.

[0364] When the pressure on the outside of the volume chamber assembly 160 is greater than the shearing force of the shear pin 164, the sealing plug 163 separates from the inner wall of the fluid channel 162, so that the pressurized liquid in the sleeve 136 enters the air chamber 161.

[0365] The sliding sleeve control device 100 and the volume chamber assembly 160 provided in this embodiment are used to solve the problem that the sliding sleeve 200 located at the bottom of the well cannot be opened due to hydraulic pressure. That is, when the operator lowers the central tube assembly 110 to the sliding sleeve 200 located at the bottom of the well, the bottom of the casing 300, the inner cylinder 220 of the sliding sleeve 200, and the sliding sleeve control device 100 form a closed space. Since the liquid is incompressible, when the sealing structure 121 blocks the inner cylinder 220, the liquid pressure at the bottom of the casing 300 is too high, and the central tube assembly 110 cannot move the inner cylinder 220 downward.

[0366] Specifically in this embodiment, the air cavity 161 of the volume chamber assembly 160 can accommodate the pressurized liquid in the enclosed space. That is, when the central tube assembly 110 drives the inner cylinder 220 of the switchable sliding sleeve 200 located at the bottom of the well to move downward, the liquid pressure in the enclosed space increases. When the liquid pressure in the enclosed space is greater than the shearing force of the shear pin 164, the shear pin 164 is sheared and broken, and the sealing plug 163 is opened, so that the liquid in the enclosed space can flow into the air cavity 161.

[0367] As shown in Figures 11, 14 to 16, 19, 24, 28, 32, and 37, in one specific embodiment,

[0368] The volume of the air cavity 161 is 1.5 to 2.5 times the volume of air compressed when the inner cylinder 220 moves between the open and closed positions of the switch sliding sleeve.

[0369] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment, by setting the size of the air cavity 161, facilitates the compression of liquid in the enclosed space into the air cavity 161. Specifically, in this embodiment, the volume of air compressed when the inner cylinder 220 moves between the position of opening the sliding sleeve and the position of closing the sliding sleeve is the product of the distance between the positions of opening and closing the sliding sleeve and the outer diameter of the inner cylinder 220.

[0370] As shown in Figures 11, 14 to 16, 19, 24, 28, 32, and 37, in one specific embodiment,

[0371] The shear force of the shear pin 164 is 1.2 to 1.3 times the product of the hydrostatic pressure at the corresponding underground depth and the cross-sectional area of ​​the sealing plug 163.

[0372] The sliding sleeve control device 100 of the switchable sliding sleeve 200 provided in this embodiment can reasonably set the shearing position of the shearing pin 164 by setting the shearing force of the shearing pin 164 to correspond to the pressure of the static water at the underground depth, so as to avoid the shearing pin 164 shearing too early or avoiding the problem of the shearing pin 164 being unable to shear underground.

[0373] Specifically, in this embodiment, the number of shear pins 164 can be multiple, wherein the total shear force of the multiple shear pins 260 needs to be 1.2 to 1.3 times the product of the hydrostatic pressure at the corresponding underground depth and the cross-sectional area of ​​the sealing plug 163. Therefore, it can be selected according to the product standard of the shear pins 164.

[0374] As shown in Figures 2, 3, 7, 9, and 10, in one specific embodiment,

[0375] The elastic claw assembly 230 includes:

[0376] Multiple first protrusions 231 are radially outwardly protruding from the outer shell assembly 210 on the outer side of the elastic claw assembly 230. The multiple first protrusions 231 are circumferentially spaced along the elastic claw assembly 230. The first protrusions 231 can be engaged in the closing locking groove 213 or the opening locking groove 214 to restrict the movement of the inner cylinder 220.

[0377] The switchable sliding sleeve 200 provided in this embodiment has a first protrusion 231 formed on the outer side of the elastic claw assembly 230, which can be engaged in the opening locking groove 214. Specifically, in this embodiment, the elastic claw assembly 230 is generally cylindrical, wherein multiple elastic claws are formed by cutting the middle part of the cylinder along its own circumference. The multiple elastic claws have a first protrusion 231 protruding along the radial outer side of the elastic claw assembly 230. The multiple first protrusions 231 are respectively formed on the multiple elastic claws. In a specific embodiment, in order to increase the locking force of the elastic claw assembly 230, the elastic claw assembly 230 can be cut into 12 to 15 elastic claws.

[0378] In this embodiment, when the external force does not exceed the rebound force of the elastic claw, the first protrusion 231 is engaged in the closing locking groove 213 or the opening locking groove 214 to achieve the axial movement and locking of the inner cylinder 220 in the outer shell assembly 210.

[0379] In one specific embodiment, since the width of the first protrusion 231 is smaller than the width of the opening locking groove 214 and the width of the closing locking groove 213, there is a possibility that the inner cylinder 220 and the outer shell assembly 210 may move within a small range.

[0380] As shown in Figures 2, 3, 7, 9, and 10, in one specific embodiment,

[0381] One end of the elastic claw assembly 230 is threadedly connected to the inner cylinder 220, and the other end of the elastic claw assembly 230 can move along the outer side wall of the inner cylinder 220 so that the elastic claw assembly 230 can expand or contract radially along the outer shell assembly 210.

[0382] The switchable sleeve 200 provided in this embodiment has a cylindrical elastic claw assembly 230. One end of the cylindrical elastic claw assembly 230 is fixedly connected to the inner cylinder 220 through a thread on the inner cylinder 220. The other end of the cylindrical elastic claw assembly 230 is movably configured so that when the first protrusion 231 is pressed down by the inner wall of the outer shell assembly 210, the other end of the elastic claw assembly 230 can move along the outer wall of the inner cylinder 220, so that the elastic claw assembly 230 can be compressed and contracted along the radial direction of the outer shell assembly 210, so as to follow the inner cylinder 220 in the inner cavity 212 of the outer shell assembly 210. When the first protrusion 231 is embedded in the closing locking groove 213 or the opening locking groove 214, the elastic claw assembly 230 can be expanded and arched along the radial direction of the outer shell assembly 210, so as to restrict the movement of the inner cylinder 220.

[0383] As shown in Figures 2, 3, 7, 9, and 10, in one specific embodiment,

[0384] The elastic claw assembly 230 also includes a second protrusion 232, which is formed at the other end of the elastic claw assembly 230. The second protrusion 232 protrudes inward along the radial direction of the outer shell assembly 210. A limiting groove 221 is formed on the outer side wall of the inner cylinder 220. The second protrusion 232 is movably embedded in the limiting groove 221 to limit the deformation range of the elastic claw assembly 230. The switchable sliding sleeve 200 provided in this embodiment can prevent the elastic claw assembly 230 from excessively deforming and losing its elasticity by providing the second protrusion 232.

[0385] Specifically in this embodiment, when the first protrusion 231 is pressed down by the inner wall of the outer shell assembly 210 or when the first protrusion 231 is embedded in the closing locking groove 213 or the opening locking groove 214, the second protrusion 232 of the elastic claw assembly 230 is embedded in the limiting groove 221 of the outer side wall of the inner cylinder 220 to move, so as to limit the degree of deformation of the elastic claw assembly 230.

[0386] As shown in Figure 7, in one specific embodiment...

[0387] The step of the closing locking groove 213 near the opening locking groove 214 forms a first switching slope 2131, and the step of the opening locking groove 214 near the closing locking groove 213 forms a second switching slope 2141, so that the elastic claw assembly 230 can retract radially along the first switching slope 2131 or the second switching slope 2141.

[0388] The angle formed between the first switching inclined surface 2131 and the axial direction of the housing assembly 210 is the ninth angle, which is 25° to 30°. The angle formed between the second switching inclined surface 2141 and the axial direction of the housing assembly 210 is the tenth angle, which is 25° to 30°.

[0389] The switchable sliding sleeve 200 provided in this embodiment, by setting the angle between the first switching ramp 2131 and the axial direction of the outer shell assembly 210, and setting the angle between the second switching ramp 2141 and the axial direction of the outer shell assembly 210, facilitates the movement of the first protrusion 231 of the elastic claw assembly 230 along the first switching ramp 2131 or the second switching ramp 2141, so that the first protrusion 231 can be pressed down by the inner wall of the outer shell assembly 210, and the elastic claw assembly 230 can be pressed down and contracted along the radial direction of the outer shell assembly 210 to move with the inner cylinder 220 in the inner cavity 212 of the outer shell assembly 210. This avoids the first switching ramp 2131 or the second switching ramp 2141 being too vertical, resulting in greater resistance, which would prevent the elastic claw assembly 230 from moving along the first switching ramp 2131 or the second switching ramp 2141 to the inner wall of the outer shell assembly 210.

[0390] As shown in Figure 7, in one specific embodiment...

[0391] The end face of the closing locking groove 213 away from the opening locking groove 214 forms a third switching slope 2132, and the end face of the opening locking groove 214 away from the closing locking groove 213 forms a fourth switching slope 2142, which is used to limit the range of movement of the elastic claw assembly 230 in the closing locking groove 213 or the opening locking groove 214.

[0392] The angle formed between the third switching inclined surface 2132 and the axial direction of the housing assembly 210 is the eleventh angle, which is 55° to 60°. The angle formed between the fourth switching inclined surface 2142 and the axial direction of the housing assembly 210 is the twelfth angle, which is 55° to 60°.

[0393] The switchable sliding sleeve 200 provided in this embodiment, by setting the angle between the third switching inclined surface 2132 and the axial direction of the outer shell assembly 210, and setting the angle between the fourth switching inclined surface 2142 and the axial direction of the outer shell assembly 210, prevents the first protrusion 231 of the elastic claw assembly 230 from moving along the third switching inclined surface 2132 or the fourth switching inclined surface 2142, so as to prevent the first protrusion 231 from moving out of the closing locking groove 213 or the opening locking groove 214, and to prevent the inner cylinder 220 from moving beyond its range in the inner cavity 212 of the outer shell assembly 210.

[0394] As shown in Figures 2, 3, 7, 9, and 10, in one specific embodiment,

[0395] The cross-section of the first protrusion 231 is an isosceles trapezoid, and the angle formed between the side of the first protrusion 231 and the axial direction of the inner cylinder 220 is the thirteenth angle, which is 55° to 60°.

[0396] The switchable sliding sleeve 200 provided in this embodiment increases the contact area between the side of the first protrusion 231 and the axial direction of the inner cylinder 220 by setting the angle between the third switching slope 2132 and the axial direction of the outer shell assembly 210 to be the same as the angle between the fourth switching slope 2142 and the axial direction of the outer shell assembly 210. It also increases the contact area between the first protrusion 231 and the third switching slope 2132 and the fourth switching slope 2142, thus preventing the first protrusion 231 from moving along the first switching slope 2131 or the second switching slope 2141.

[0397] As shown in Figures 5 and 6, in one specific embodiment...

[0398] An installation step 2111 is formed inside the fracturing channel 211. An outer seal 240 is provided on the installation step 2111. The outer seal 240 includes an elastic baffle 241 and a one-way element 242. The one-way element 242 is used to block external fluid from entering. The elastic baffle 241 is connected to the inner wall of the fracturing channel 211. The one-way element 242 is located between the elastic baffle 241 and the installation step 2111 to fix the one-way element 242 inside the fracturing channel 211.

[0399] The switchable sleeve 200 provided in this embodiment blocks the fracturing channel 211 through the one-way element 242, preventing the slurry outside the switchable sleeve 200 from entering the interior of the switchable sleeve 200, that is, entering the inner cavity 212 of the outer shell assembly 210, and only allowing the fracturing fluid inside the switchable sleeve 200 to enter the formation through the fracturing channel 211; specifically in this embodiment, the elastic baffle 241 is used to fix the one-way element 242.

[0400] As shown in Figures 5 and 6, in one specific embodiment...

[0401] The unidirectional element 242 is a soluble sheet with two intersecting fracturing slits 2421 at its center to prevent external fluid from entering. The width of the fracturing slits 2421 is 0.1 mm to 0.2 mm, and the thickness of the soluble sheet is 0.4 mm to 0.5 mm. The soluble sheet is made of soluble magnesium alloy material.

[0402] The switchable sleeve 200 provided in this embodiment allows high-pressure fracturing fluid to break the one-way element 242 through the fluid force generated by the fracturing incision 2421 on the one-way element 242, so that the fracturing fluid can enter the formation through the fracturing channel 211. At the same time, the one-way element 242 can effectively prevent external slurry from entering the interior of the switchable sleeve 200 before the fracturing fluid delivery step.

[0403] In this embodiment, the one-way element 242 is provided with a soluble sheet made of soluble material, so that when the one-way element 242 cannot be broken during fracturing operations, the fracturing channel 211 can be opened by completely dissolving it.

[0404] In one specific embodiment, by limiting the incision width of the fracturing incision 2421, the thickness of the soluble sheet, and the material of the soluble sheet, the fragmentation of the soluble sheet during fracturing operations can be effectively improved, while also preventing the soluble sheet from fragmenting before the fracturing step.

[0405] As shown in Figures 5 and 6, in one specific embodiment...

[0406] The aspect ratio of the fracturing channel 211 is greater than 3.5.

[0407] In the switchable sliding sleeve 200 provided in this embodiment, the two ends of the fracturing channel 211 are semi-circular and the middle is rectangular. By limiting the length-to-width ratio of the fracturing channel 211, the port shape of the fracturing channel 211 can effectively reduce the fracturing pressure required by the formation.

[0408] As shown in Figures 2 to 6, in one specific embodiment...

[0409] The total cross-sectional area of ​​the multiple fracturing channels 211 is 1.1 to 1.5 times the cross-sectional area of ​​the inner cylinder 220.

[0410] The switchable sleeve 200 provided in this embodiment, by corresponding the total cross-sectional area of ​​the multiple fracturing channels 211 to the cross-sectional area of ​​the inner cylinder 220, can make the total cross-sectional area of ​​the multiple fracturing channels 211 larger than the cross-sectional area of ​​the inner cylinder 220. This prevents throttling pressure loss when pressurized fluid enters the fracturing channels 211 from the inside of the switchable sleeve 200, and also avoids erosion of the fracturing channels 211 by the pressurized fluid, thus preventing damage to the switchable sleeve 200. At the same time, limiting the total cross-sectional area of ​​the multiple fracturing channels 211 to 1.1 to 1.5 times the cross-sectional area of ​​the inner cylinder 220 facilitates fracturing operations of the formation by the fracturing fluid, making the formation easier to break up.

[0411] As shown in Figures 2 to 7, in one specific embodiment...

[0412] The lower end of the outer casing assembly 210 is also formed with an upper buckle section, and the inner wall of the outer casing assembly 210 is also provided with a first step 215 and a second step 216 along its own axial direction. The second step 216 is formed at the upper end of the upper buckle section, and the inner cylinder 220 moves between the first step 215 and the second step 216 along the axial direction of the outer casing assembly 210.

[0413] When one end of the inner cylinder 220 abuts against the first step 215, the elastic claw assembly 230 is embedded in the closing locking groove 213. When the other end of the inner cylinder 220 abuts against the second step 216, the elastic claw assembly 230 is embedded in the opening locking groove 214.

[0414] The switchable sliding sleeve 200 provided in this embodiment, through the setting of the first step 215 and the second step 216, can prevent the first protrusion 231 of the elastic claw assembly 230 from moving out of the closing locking groove 213 or the opening locking groove 214, and prevent the inner cylinder 220 from moving beyond its range in the inner cavity 212 of the outer shell assembly 210.

[0415] As shown in Figure 7, in one specific embodiment...

[0416] The inner wall of the inner cylinder 220 is provided with a first locking groove 222 and a second locking groove 223 in a sequential recessed manner from the wellhead to the bottom of the well along its own axial direction. The first locking groove 222 and the second locking groove 223 are respectively used to lock the first boss 1311A and the second boss 1311B formed on the outer peripheral wall of the positioning element 1311.

[0417] The switchable sliding sleeve 200 provided in this embodiment, by forming a first engaging groove 222 and a second engaging groove 223 on the inner wall of the inner cylinder 220, facilitates the engagement of the first boss 1311A and the second boss 1311B of the sliding sleeve control device 100. This allows the positioning element 1311 to move through the inner cylinder 220 by engaging the first boss 1311A with the first engaging groove 222 and engaging the second boss 1311B with the second engaging groove 223. At the same time, it also facilitates the positioning of the sliding sleeve control device 100 and the inner cylinder 220 by engaging the first boss 1311A with the first engaging groove 222 and engaging the second boss 1311B with the second engaging groove 223 when the positioning element 1311 is in the extended state.

[0418] As shown in Figure 7, in one specific embodiment...

[0419] The end face of the first latching groove 222 away from the second latching groove 223 forms a first latching slope 2221, and the end face of the second latching groove 223 away from the first latching groove 222 forms a second latching slope 2231, so that the positioning element 1311 can slide into the first latching groove 222 or the second latching groove 223 along the first latching slope 2221 or the second latching slope 2231;

[0420] The angle formed between the first clamping inclined surface 2221 and the axial direction of the inner cylinder 220 is the fourteenth angle, which is 20° to 25°; the angle formed between the second clamping inclined surface 2231 and the axial direction of the inner cylinder 220 is the fifteenth angle, which is 25° to 30°.

[0421] The switchable sliding sleeve 200 provided in this embodiment, by limiting the included angle formed between the first snap-fit ​​inclined surface 2221 and the axial direction of the inner cylinder 220 to 20° to 25°, and the included angle formed between the second snap-fit ​​inclined surface 2231 and the axial direction of the inner cylinder 220 to 25° to 30°, can facilitate the first boss 1311A to slide from the first snap-fit ​​inclined surface 2221 into the first snap-fit ​​groove 222, or facilitate the second boss 1311B to slide from the second snap-fit ​​inclined surface 2231 into the second snap-fit ​​groove 223.

[0422] As shown in Figure 7, in one specific embodiment...

[0423] The end face of the first latching groove 222 near the second latching groove 223 forms a third latching slope 2222, which is used to restrict the first boss 1311A within the first latching groove 222. The end face of the second latching groove 223 near the first latching groove 222 forms a fourth latching slope 2232, which is used to restrict the second boss 1311B within the second latching groove 223.

[0424] The angle formed between the third clamping inclined surface 2222 and the axial direction of the inner cylinder 220 is the sixteenth angle, which is 80° to 85°; the angle formed between the fourth clamping inclined surface 2232 and the axial direction of the inner cylinder 220 is the seventeenth angle, which is 80° to 85°.

[0425] The switchable sliding sleeve 200 provided in this embodiment can prevent the first boss 1311A from sliding out of the first locking groove 222 from the third locking slope 2222, or prevent the second boss 1311B from sliding out of the second locking groove 223 from the fourth locking slope 2232, by limiting the included angle between the third locking slope 2222 and the axial direction of the inner cylinder 220 and the included angle between the fourth locking slope 2232 and the axial direction of the inner cylinder 220 to 80° to 85°.

[0426] In one specific embodiment, the length of the first latching groove 222 is 3mm to 5mm longer than the length of the first protrusion 1311A of the positioning element 1311, so that the first protrusion 1311A can smoothly enter the first latching groove 222, and the length of the second latching groove 223 is 3mm to 5mm longer than the length of the second protrusion 1311B of the positioning element 1311, so that the second protrusion 1311B can smoothly enter the second latching groove 223.

[0427] As shown in Figure 3, in one specific embodiment...

[0428] The inner wall of the outer shell assembly 210 is also recessed with a filter groove 217. The filter groove 217 is located near the second step 216. A felt ring 250 is provided in the filter groove 217 to filter the liquid between the outer shell assembly 210 and the inner cylinder 220. The felt ring 250 is composed of a felt material mesh with a mesh number of less than 100.

[0429] The switchable sliding sleeve 200 provided in this embodiment, by providing a filter groove 217 and a felt ring 250 near the second step 216, can, on the one hand, prevent large particles of proppant from entering the gap between the outer shell assembly 210 and the inner cylinder 220, and on the other hand, allow the felt ring 250 to pass between the outer shell assembly 210 and the inner cylinder 220. In this embodiment, the felt ring 250 can be felt or other filter materials with a mesh size of less than 100 mesh.

[0430] Specifically in this embodiment, when the inner cylinder 220 moves downward, the fluid in the gap between the inner cylinder 220 and the outer shell assembly 210 can be squeezed out. When the inner cylinder 220 moves upward, the liquid in the inner cylinder 220 can enter the gap between the inner cylinder 220 and the outer shell assembly 210, while filtering out impurities and preventing the movement of the inner cylinder 220 from being obstructed.

[0431] In one specific embodiment, to prevent impurities from entering the space between the inner cylinder 220 and the outer shell assembly 210 from the switchable sleeve 200, optionally, the gap between the inner cylinder 220 and the outer shell assembly 210 is filled with an anti-emulsifying sealant, wherein the sealant may have a viscosity of 90 mmHg at 60°C. 2 / s~100mm 2 / s of grease, including butter, engine oil, etc.

[0432] In one specific embodiment, to prevent impurities from entering the space between the inner cylinder 220 and the outer shell assembly 210 from the switchable sliding sleeve 200, a sealing structure 270 is provided near the first step 215. The sealing structure 270 is provided between the inner cylinder 220 and the outer shell assembly 210. The sealing structure 270 may be composed of a first sealing ring 271, two second sealing rings 272, and two third sealing rings 273. The two second sealing rings 272 are respectively provided at both axial ends of the first sealing ring 271, and the two third sealing rings 273 are respectively provided at the axial end of the second sealing ring 272 away from the first sealing ring 271.

[0433] The first sealing ring 271 is made of rubber, the second sealing ring 272 is made of plastic, and the third sealing ring 273 is made of metal. The third sealing ring 273 serves as a supporting frame. The second sealing ring 272, made of plastic, compresses the first sealing ring 271 (made of rubber) and connects to the third sealing ring 273, ensuring a tight seal between the inner cylinder 220 and the outer shell assembly 210.

[0434] In a specific embodiment, the first sealing ring 271, the second sealing ring 272, and the third sealing ring 273 are all generally "O-ring" sealing ring structures. The first sealing ring 271 may be made of hydrogenated nitrile material, the second sealing ring 272 may be made of polytetrafluoroethylene material, and the third sealing ring 273 may be made of copper material.

[0435] In this embodiment, the first sealing ring 271 is a circular sealing ring, and the second sealing ring 272 has a generally zigzag cross-section, that is, it is composed of inner and outer sealing rings that are nested and connected to each other. One sealing ring of the second sealing ring 272 is inclined in one direction, and the other sealing ring of the second sealing ring 272 is inclined in another direction to form a "slanted zigzag" structure. In this embodiment, the second sealing ring 272 has nested corner portions and sharp corner portions. The corner portion of the second sealing ring 272 is used to snap onto the rubber-made first sealing ring 271. The sharp corner portion of the second sealing ring 272 is set towards the inside of the corner of the third sealing ring 273, so that the inside of the corner of the third sealing ring 273 can clamp the sharp corner portion of the second sealing ring 272, achieving a tight seal. At the same time, it can also improve the sealing effect between the inner cylinder 220 and the outer shell assembly 210, avoiding the problem of being unable to repeatedly open and close the fracturing channel 211 due to wear, scaling, corrosion, etc. of the sealing ring.

[0436] In one specific embodiment, to prevent impurities from affecting the relative sliding of the inner cylinder 220 and the outer shell assembly 210, carbonitriding treatment can be applied to the outer surface of the inner cylinder 220 and the inner surface of the outer shell assembly 210 to improve the corrosion resistance and erosion resistance of the outer surface of the inner cylinder 220 and the inner surface of the outer shell assembly 210.

[0437] The surfaces of the first and second card slots 222 and 223 are treated with a nano-ceramic spraying process to reduce the adhesion of cement and other dirt, which can prevent cement from bonding in the first and second card slots 222 and 223, thus avoiding the problem that the sliding sleeve control device 100 cannot accurately locate the first and second card slots 222 and 223.

[0438] As shown in Figure 3, in one specific embodiment...

[0439] The outer casing assembly 210 and the inner cylinder 220 are connected by a pin 260, which is used to fix the relative position of the inner cylinder 220 and the outer casing assembly 210 during the process of lowering the switchable sliding sleeve 200 into the well. When the pressurized liquid in the casing 300 pushes the sealing structure 121, the pin 260 breaks.

[0440] In this embodiment, the switchable sleeve 200 is provided with a pin 260 between the inner cylinder 220 and the outer casing assembly 210 to ensure the safe entry of the switchable casing 300 into the wellbore 500. One end of the pin 260 is connected to the outer casing assembly 210, and the other end is connected to the inner cylinder 220, so as to fix the inner cylinder 220 and the outer casing assembly 210 and prevent the inner cylinder 220 from moving relative to the wellbore 500 when the switchable sleeve 200 is lowered into the wellbore 500. When the external force applied to the inner cylinder 220 exceeds the shear force of the pin 260, the pin 260 is sheared, and the sleeve control device 100 can drive the inner cylinder 220 to move downward to expose the fracturing channel 211, so that the fracturing fluid can enter the formation from the casing 300 through the fracturing channel 211.

[0441] Implementation Method 2

[0442] As shown in Figures 1 to 38, in another aspect, this disclosure also provides a control method for a switchable sliding sleeve, used to open the aforementioned switchable sliding sleeve 200, wherein the control method for the switchable sliding sleeve includes:

[0443] When the switchable sleeve 200 needs to be opened:

[0444] Multiple switchable sliding sleeves 200, connected at intervals of casing 300, are lowered from the wellhead along the inner wall of wellbore 500 to the section of wellbore 500 to be fracturing.

[0445] Step S1: Cement and cleaning fluid are injected into the inner channel of casing 300 in sequence, so that cement rings are formed between casing 300 and wellbore 500 or between switchable sliding sleeve 200 and wellbore 500.

[0446] Step S2: The sliding sleeve control device 100 of the track-changing element 111 located at the lower end of the short track 133 moves down from the wellhead along the channel of the casing 300 to the side of any switchable sliding sleeve 200 near the bottom of the well, and the switchable sliding sleeve 200 is in the closed state.

[0447] Step S3: The plugging ball 400 moves down from the wellhead along the inner cavity 212 of the central tube assembly 110 to the ball seat 112, so as to increase the liquid pressure in the inner cavity 212 of the central tube assembly 110. The increased liquid pressure is transmitted to the cylinder cavity 1313F through the liquid slot 1313G, the liquid delivery channel 1313H, and the liquid hole 1313I in sequence, so as to push the sliding sleeve element 1313B to move away from the positioning element 1311, and cause the positioning element 1311 to expand along the radial H of the central tube assembly 110.

[0448] Step S4: The central tube assembly 110 moves towards the wellhead, and the track-changing element 111 moves from the lower end of the short track 133 to the upper end of the connecting channel 134, driving the control assembly 130 to move up until the positioning element 1311 is engaged with the inner wall of the inner cylinder 220.

[0449] Step S5: The central tube assembly 110 moves downward toward the bottom of the well, the rail-changing element 111 moves down from the upper end of the connecting channel 134 to the lower end of the long rail 132, and the central tube assembly 110 drives the sealing assembly 120 to move down and abut against the upper end of the control assembly 130, and the sealing structure 121 expands along the radial H of the central tube assembly 110 to the sealing inner cylinder 220, and the slip 1382A expands along the radial H of the central tube assembly 110 and engages with the inner wall of the inner cylinder 220;

[0450] Step S6: Pump pressurized fluid into the annulus between the casing 136 and the sliding sleeve control device 100 from the wellhead. The pressurized fluid can push the sealing structure 121 and drive the first protrusion 231 connected to the inner cylinder 220 to move down from the closing locking groove 213 to the opening locking groove 214 through the positioning element 1311 and the slip 1382A, thereby releasing the inner cylinder 220 from blocking the fracturing channel 211 of the outer shell assembly 210, so that the fracturing channel 211 is connected to the inner cavity 212 of the inner cylinder 220, and the pressurized fluid completes the fracturing operation through the fracturing channel 211.

[0451] The switchable sliding sleeve control method provided in this embodiment can accurately position the inner cylinder 220 through the sliding sleeve control device 100, so that the sliding sleeve control device 100 can be stably engaged on the inner cylinder 220, thereby driving the inner cylinder 220 to move downward and realize the opening of the switchable sliding sleeve 200.

[0452] Specifically, in this embodiment, before step S1, multiple switchable sleeves 200 are first connected through a casing 300, and the multiple switchable sleeves 200 can be lowered to the designed depth inside the wellbore 500 through the casing 300; in step S1, cement slurry is injected into the inside of the casing 300, and then clean water is injected to press the cement slurry from the bottom of the casing 300 into the annulus between the casing 300 and the wellbore 500 or the annulus between the switchable sleeves 200 and the wellbore 500. After the cement slurry solidifies into a cement ring, in this state, the inner cylinder 220 is located at the position of sealing the fracturing channel 211, and the inner cylinder 220 and the outer shell assembly 210 are fixedly connected by pins 260.

[0453] In this embodiment, in step S2, the central tube assembly 110 is connected to the lower end of the tubing 600, and the rail-changing element 111 is placed at the lower end of the short rail 133. Then, the sliding sleeve control device 100 is lowered into the casing 300 through the tubing 600. At this time, the control component 130 is moved towards the bottom of the well by the rail-changing element 111 abutting against the lower end of the short rail 133. The upper end of the central tube assembly 110 is connected to the upper part of the packer assembly 120, which drives the packer assembly 120 to move downward. At this time, the sliding sleeve control device 100 can sequentially open each switchable sliding sleeve 200 from the wellhead to the bottom of the well. In another embodiment, the switching sleeves 200 can also be opened sequentially from the bottom of the wellhead to the wellhead. In this embodiment, the sliding sleeve control device 100 is lowered to the lower end of each switchable sliding sleeve 200.

[0454] In this embodiment, in step S3, by lowering the sealing ball 400, the positioning element 1311 can be pushed to move outward along the radial direction H of the central tube assembly 110 to the maximum limit.

[0455] In this embodiment, in step S4, the central tube assembly 110 is lifted by the oil pipe 600. The central tube assembly 110 drives the track-changing element 111 to move from the lower end of the short track 133 to the upper end of the short track 133. It slides into the upper end of the connecting channel 134 by abutting against the first connecting channel wall 1341. The central tube assembly 110 is lifted further, driving the control assembly 130 and the sealing assembly 120 to move upward. The positioning element 1311 also moves upward. When the first boss 1311A and the second boss 1311B of the positioning element 1311 slide into the first locking groove 222 and the second locking groove 223 respectively, the locking assembly 131 and the inner cylinder 220 are locked together.

[0456] In this embodiment, in step S5, the central tube assembly 110 is lowered through the oil pipe 600. The central tube assembly 110 can drive the track-changing element 111 to slide from the upper end of the connecting channel 134 into the long track 132 by abutting against the wall 1342 of the second connecting channel. As the central tube assembly 110 continues to be lowered, the central tube assembly 110 can drive the track-changing element 111 to move along the long track 132 to the lower end of the long track 132. During this process, the central tube assembly 110 can push the lower end of the sealing assembly 120 to abut against the upper end of the control assembly 130 and drive the sealing structure 121 to expand outward along the radial direction H of the central tube assembly 110 to seal the inner cylinder 220. At the same time, the contact between the pushing member 122 and the slip assembly 138 can also push the slip 1382A to expand along the radial direction H of the central tube assembly 110 to engage with the inner wall of the inner cylinder 220.

[0457] In this embodiment, in step S6, pressurized fluid is pumped into the casing 300. The pressurized fluid can exert pressure on the inner cylinder 220 through the sliding sleeve control device 100. When the pressure applied to the inner cylinder 220 exceeds the shear force of the pin 260, the pin 260 is sheared off. The sliding sleeve control device 100 can drive the inner cylinder 220 to move downward to expose the fracturing channel 211, so that the fracturing fluid can enter the formation from the casing 300 through the fracturing channel 211.

[0458] In this embodiment, after step S6, the liquid pressure inside the central tube assembly 110 is released, causing the sealing ball 400 to move out of the ball seat 112. The positioning element 1311 moves inward along the radial direction H of the central tube assembly 110, so that the positioning element 1311 separates from the inner cylinder 220. Further, the central tube assembly 110 is lifted through the oil pipe 600, and the central tube assembly 110 drives the track-changing element 111 to move from the lower end of the long track 132 to the upper end of the long track 132. It then slides into the upper end of the connecting channel 134 by abutting against the first connecting channel wall 1341. Then, the central tube assembly 110 is lowered through the oil pipe 600, and the central tube assembly 110 can drive the track-changing element 111 from the upper end of the connecting channel 134. The end slides into the short track 133 by abutting against the second connecting wall 1342, and the central tube assembly 110 continues to be lowered. The central tube assembly 110 can drive the track changing element 111 to move along the short track 133 to the lower end of the short track 133. At this time, the lower end of the sealing assembly 120 separates from the upper end of the control assembly 130, so that the sealing structure 121 retracts inward along the radial H of the central tube assembly 110 until it separates from the inner cylinder 220. The pushing element 122 separates from the slip assembly 138, so that the slip 1382A retracts inward along the radial H of the central tube assembly 110 until it separates from the inner cylinder 220. At this time, it is convenient for the sliding sleeve control device 100 to continue to move down along the sleeve 300 to another switchable sliding sleeve 200.

[0459] As shown in Figures 1 to 38, in another aspect, this disclosure also provides a control method for a switchable sliding sleeve, used to close the aforementioned switchable sliding sleeve 200, wherein the control method for the switchable sliding sleeve includes:

[0460] When the switchable sleeve 200 needs to be closed:

[0461] Step S1: The sliding sleeve control device 100 of the track-changing element 111 located at the upper end of the connecting channel 134 moves along the channel of the casing 300 to the side of any switchable sliding sleeve 200 near the bottom of the well, and the switchable sliding sleeve 200 is in the open state.

[0462] Step S2: The plugging ball 400 moves down from the wellhead along the inner cavity 212 of the central tube assembly 110 to the ball seat 112, so as to increase the liquid pressure in the inner cavity 212 of the central tube assembly 110. The increased liquid pressure is transmitted to the cylinder cavity 1313F through the liquid slot 1313G, the liquid delivery channel 1313H, and the liquid hole 1313I in sequence, so as to push the sliding sleeve element 1313B to move away from the positioning element 1311, and cause the positioning element 1311 to expand along the radial H of the central tube assembly 110.

[0463] Step S3: The central tube assembly 110 moves towards the wellhead and drives the control assembly 130 upward until the positioning element 1311 engages with the inner wall of the inner cylinder 220;

[0464] Step S4: The central tube assembly 110 continues to move towards the wellhead. The central tube assembly 110 drives the first protrusion 231 connected to the inner cylinder 220 to move from the opening locking groove 214 to the closing locking groove 213, so that the inner cylinder 220 blocks the fracturing channel 211.

[0465] The switchable sliding sleeve control method provided in this embodiment can accurately position the inner cylinder 220 through the sliding sleeve control device 100, so that the sliding sleeve control device 100 can be stably engaged on the inner cylinder 220, thereby driving the inner cylinder 220 to move upward and realize the opening of the switchable sliding sleeve 200.

[0466] In this embodiment, in step S1, the sliding sleeve control device 100 is located near the bottom of the well in the casing 300. The central tube assembly 110 is connected to the lower end of the tubing 600. After the rail-changing element 111 is placed at the upper end of the connecting channel 134, the central tube assembly 110 is lifted through the tubing 600. At this time, the control assembly 130 is moved towards the wellhead by the rail-changing element 111 abutting against the upper end of the connecting channel 134. At this time, the sliding sleeve control device 100 can sequentially close each switchable sliding sleeve 200 from the bottom of the well to the wellhead. In another embodiment, the switchable sliding sleeve 200 can also be closed sequentially from the wellhead to the bottom of the well. In this embodiment, the sliding sleeve control device 100 is lifted to the lower end of each switchable sliding sleeve 200.

[0467] In this embodiment, in step S2, by lowering the sealing ball 400, the positioning element 1311 can be pushed to move outward along the radial direction H of the central tube assembly 110 to the maximum limit.

[0468] In this embodiment, in step S3, the central tube assembly 110 is lifted by the oil pipe 600, which drives the control assembly 130 and the sealing assembly 120 to move upward. The positioning element 1311 also moves upward. When the first boss 1311A and the second boss 1311B of the positioning element 1311 slide into the first locking groove 222 and the second locking groove 223 respectively, the locking assembly 131 and the inner cylinder 220 are locked together.

[0469] In this embodiment, in step S4, the central tube assembly 110 is further lifted through the oil pipe 600, and the inner cylinder 220 is moved upward by the sliding sleeve control device 100. The first protrusion 231 of the elastic claw assembly 230 moves from the opening locking groove 214 to the inner wall of the outer shell assembly 210. When the first protrusion 231 of the elastic claw assembly 230 is pressed down by the inner wall of the outer shell assembly 210, the other end of the elastic claw assembly 230 can move along the outer side wall of the inner cylinder 220, so that the elastic claw assembly 230 can be pressed down and contracted along the radial direction of the outer shell assembly 210, so as to follow the inner cylinder 220 in the inner cavity 212 of the outer shell assembly 210. When the first protrusion 231 of the elastic claw assembly 230 is embedded in the closing locking groove 213, the inner cylinder 220 blocks the fracturing channel 211, and the opening and closing of the switchable sliding sleeve 200 is completed.

[0470] In this embodiment, after step S4, the liquid pressure inside the central tube assembly 110 is released, causing the sealing ball 400 to move out of the ball seat 112, and the positioning element 1311 moves inward along the radial direction H of the central tube assembly 110 to separate the positioning element 1311 from the inner cylinder 220; furthermore, the central tube assembly 110 is lifted through the oil pipe 600 to lift the sliding sleeve control device 100 to the lower end side of another switchable sliding sleeve 200.

[0471] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of this disclosure. It should be understood that the above are only specific embodiments of this disclosure and are not intended to limit the scope of protection of this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A switchable sliding sleeve, characterized in that, include: The outer shell assembly has multiple fracturing channels circumferentially provided. The fracturing channels are respectively connected to the external space and the inner cavity of the outer shell assembly. The inner wall of the outer shell assembly is recessed along its own axis from the wellhead to the bottom of the well to form a closing locking groove and an opening locking groove. The inner cylinder is movably inserted into the inner cavity along the axial direction of the outer shell assembly. An elastic claw assembly with an expanding tendency is sleeved on the outer side of the inner cylinder to engage in the closing locking groove or the opening locking groove. The elastic claw assembly can expand or contract radially along the outer shell assembly so that the elastic claw assembly can move with the inner cylinder in the inner cavity. A sliding sleeve control device is movably disposed inside the inner cavity and the inner cylinder. The sliding sleeve control device has a locking component that can lock the inner cylinder. The sliding sleeve control device can drive the inner cylinder to move along the axial direction of the outer shell assembly through the locking component. Specifically, when the inner cylinder moves to the point where the elastic claw assembly engages with the closing locking groove, the inner cylinder blocks the fracturing channel; when the inner cylinder moves to the point where the elastic claw assembly engages with the opening locking groove, the inner cylinder releases the blockage of the fracturing channel, thereby connecting the fracturing channel with the inner cavity.

2. The switchable sliding sleeve of claim 1, wherein, The sliding sleeve control device includes: a central tube assembly for passing through the casing, the inner cylinder, and the inner cavity, wherein the upper end of the central tube assembly extends from the wellhead to the bottom of the well, and the central tube assembly is provided with a track-changing element protruding radially outward; A sealing assembly is sleeved on the outside of the central tube assembly, with the upper end of the central tube assembly connected to the upper end of the sealing assembly, so that the central tube assembly can drive the sealing assembly to move along the axial direction of the central tube assembly. The sealing assembly includes a sealing structure that can expand radially along the central tube assembly. A control assembly is movably sleeved on the central tube assembly, and the control assembly is located on the lower side of the sealing assembly. The control assembly includes a snap-fit ​​assembly, and a long track and a short track extending along the axial direction of the central tube assembly. The snap-fit ​​assembly can move radially along the central tube assembly and snap-fit ​​onto the inner wall of the inner cylinder. The upper end of the long track is connected to the upper end of the short track. The track-changing element is movably embedded in the long track and the short track. When the track-changing element is located at the lower end of the short track, the packer assembly is separated from the control assembly, and the packer structure is in a contracted state, allowing the central tube assembly to drive the packer assembly and the control assembly to pass through the casing and the inner cylinder from the wellhead to the bottom of the well. When the track-changing element moves along the long track towards its lower end, the central tube assembly pushes the lower end of the packer assembly against the upper end of the control assembly, causing the packer structure to expand radially along the central tube assembly to seal the inner cylinder. The locking assembly locks onto the inner wall of the inner cylinder. The pressurized fluid inside the sleeve can push the sealing structure and, through the snap-fit ​​assembly, drive the sliding sleeve control device and the inner cylinder to move downward along the axial direction of the switchable sliding sleeve, thereby opening the switchable sliding sleeve; when the track-changing element is located at the upper end of the long track or the upper end of the short track, the snap-fit ​​assembly snaps into the inner wall of the inner cylinder, the sealing assembly separates from the control assembly, and the sealing structure is in a contracted state, so that the central tube assembly can, through the snap-fit ​​assembly, drive the sliding sleeve control device and the inner cylinder to move upward along the axial direction of the switchable sliding sleeve, thereby closing the switchable sliding sleeve.

3. The switchable sliding sleeve according to claim 2, characterized in that, The upper end of the long track and the upper end of the short track are aligned axially on the central tube assembly, and the distance from the upper end to the lower end of the long track on the central tube assembly is greater than the distance from the upper end to the lower end of the short track on the central tube assembly.

4. The switchable sliding sleeve according to claim 3, characterized in that, There are multiple long tracks and multiple short tracks. The multiple long tracks are arranged at intervals along the circumference of the control component. The multiple short tracks are respectively inserted between two adjacent long tracks. The upper end of each short track is connected to the upper end of the two adjacent long tracks.

5. The switchable sliding sleeve according to claim 4, characterized in that, The upper ends of adjacent long tracks are connected to the upper ends of short tracks by a connecting channel. The connecting channel has a first connecting channel wall and a second connecting channel wall that are staggered. The first connecting channel wall is located on the side of the connecting channel near the upper end of the central tube assembly, and the second connecting channel wall is located on the side of the connecting channel near the lower end of the central tube assembly. The first connecting wall extends to the upper end of the short track or the upper end of the long track, so that the track-changing element located at the upper end of the short track or the upper end of the long track can move upward along the first connecting wall to the upper end of the connecting track; the second connecting wall extends from the short track or the long track to the upper end of the connecting track, so that the track-changing element located at the upper end of the connecting track can move downward along the second connecting wall into the short track or the long track.

6. The switchable sliding sleeve according to claim 5, characterized in that, The first connecting channel wall and the projection of the axis of the central tube assembly onto the horizontal plane form a first included angle, which is 25° to 35°. The second connecting channel wall and the projection of the axis of the central tube assembly onto the horizontal plane form a second included angle, which is 25° to 35°.

7. The switchable sliding sleeve according to claim 5, characterized in that, The control component includes a track cylinder and a sleeve. The track cylinder extends axially along the central tube assembly and is sleeved on the outside of the central tube assembly. The short track, the long track, and the connecting channel are all formed on the peripheral wall of the track cylinder, and the sleeve is sealed on the radial outside of the track cylinder.

8. The switchable sliding sleeve according to claim 7, characterized in that, The control assembly includes a straightening element connected to the lower end of the sleeve. The outer peripheral wall of the straightening element has a plurality of first grooves. A first friction element and a first elastic element are provided in the first groove. The first elastic element is connected between the first friction element and the first groove to push the first friction element to move radially outward along the central tube assembly and abut against the inner wall of the outer shell assembly of the switch slide sleeve.

9. The switchable sliding sleeve according to claim 8, characterized in that, The frictional force between the straightening element and the housing assembly is 1.0 to 1.5 times the weight of the control assembly.

10. The switchable sliding sleeve according to claim 7, characterized in that, The lower end of the snap-fit ​​assembly is connected to the upper end of the sleeve. The snap-fit ​​assembly includes a positioning element, a second groove, and a push-pull element. The positioning element passes through the second groove, and the push-pull element is connected between the positioning element and the second groove to drive the positioning element to snap or separate from the inner wall of the inner cylinder along the radial direction of the central tube assembly.

11. The switchable sliding sleeve according to claim 10, characterized in that, The positioning element is provided with a first boss and a second boss protruding radially outward along the central tube assembly. The first boss and the second boss are spaced apart along the axial direction of the central tube assembly. The first boss and the second boss are respectively used to engage with the first engaging groove and the second engaging groove formed on the inner wall of the inner cylinder.

12. The switchable sliding sleeve according to claim 10, characterized in that, The push-pull element includes a second elastic element connected between the positioning element and the second groove, for pushing the positioning element to move radially outward along the central tube assembly and engaging with the inner wall of the inner cylinder.

13. The switchable sliding sleeve according to claim 12, characterized in that, The push-pull element also includes a sliding sleeve element. The sliding sleeve element is movably disposed along the axial direction of the central tube assembly. A sliding sleeve conical wall is formed at one end of the sliding sleeve element facing the positioning element, and a snap-fit ​​conical wall is formed at one end of the positioning element facing the sliding sleeve element. The sliding sleeve conical wall and the snap-fit ​​conical wall are correspondingly fitted together. Specifically, when the sliding sleeve element moves toward the positioning element, the sliding sleeve cone wall slides upward along the engaging cone wall to push the positioning element to move radially inward along the central tube assembly; when the sliding sleeve element moves away from the positioning element, the sliding sleeve cone wall slides downward along the engaging cone wall to provide space for the positioning element to move radially outward along the central tube assembly.

14. The switchable sliding sleeve according to claim 13, characterized in that, There are multiple positioning elements and second grooves. Multiple second grooves are arranged at intervals along the circumference of the snap-fit ​​assembly on the outer wall of the snap-fit ​​assembly, and multiple positioning elements are respectively inserted into multiple second grooves.

15. The switchable sliding sleeve according to claim 13 or 14, characterized in that, There are two sliding sleeve elements, which are respectively disposed on both sides of the positioning element along the axial direction of the central tube assembly. The sliding sleeve conical wall of the sliding sleeve element is in contact with the snap-fit ​​conical wall of the positioning element.

16. The switchable sliding sleeve according to claim 13, characterized in that, The projection of the sliding sleeve conical wall and the axis of the central tube assembly onto the horizontal plane forms a third included angle, which is 20° to 25°. The fourth included angle is formed between the projection of the snap-fit ​​cone wall and the axis of the central tube assembly onto the horizontal plane, and the fourth included angle is 20° to 25°.

17. The switchable sliding sleeve according to claim 13, characterized in that, The sliding sleeve component includes a sliding element, a third elastic element, and a sliding sleeve hydraulic cylinder. The sliding sleeve is movably fitted radially outside the groove wall of the second groove along the axial direction of the central tube assembly. The sliding sleeve cone wall is formed at one end of the sliding sleeve facing the positioning element. The third elastic element is compressedly connected to the end of the sliding sleeve away from the positioning element along the axial direction of the central tube assembly to push the sliding sleeve towards the positioning element. The sliding sleeve hydraulic cylinder is telescopically connected between the sliding sleeve and the groove wall of the second groove along the axial direction of the central tube assembly to push the sliding sleeve away from the positioning element.

18. The switchable sliding sleeve according to claim 17, characterized in that, The sliding sleeve hydraulic cylinder includes a cylinder chamber, a fluid slot, a fluid delivery channel, and a fluid orifice. The liquid slit is formed on the inner wall of the central tube assembly, and the infusion channel is formed between the groove wall of the second groove and the central tube assembly. The liquid hole is formed on the groove wall of the second groove. The cylinder cavity is formed by the groove wall of the second groove and the sliding sleeve. The pressurized liquid inside the central tube assembly can enter the cylinder cavity along the liquid slit, the infusion channel and the liquid hole, and the pressurized liquid in the cylinder cavity can push the sliding sleeve to move away from the positioning element along the axial direction of the central tube assembly.

19. The switchable sliding sleeve according to claim 18, characterized in that, The central tube assembly has a ball seat inside, which is located on the side of the well relative to the fluid gap and close to the bottom of the well. A plugging ball dropped from the wellhead can plug the ball seat and guide the pressurized fluid inside the central tube assembly to the fluid gap.

20. The switchable sliding sleeve according to claim 18, characterized in that, A plurality of first sealing elements are provided in a ring between the groove wall of the second groove and the sliding sleeve. The plurality of first sealing elements are respectively disposed at both ends of the cylinder cavity along the axial direction of the central tube assembly to seal the cylinder cavity. The first sealing elements are made of rubber material.

21. The switchable sliding sleeve according to claim 18, characterized in that, The snap-fit ​​assembly further includes a plurality of second sealing elements, which are arranged around the outer periphery of the central tube assembly. The plurality of second sealing elements are respectively disposed at both ends of the groove wall of the second groove along the axial direction of the central tube assembly to seal the infusion channel.

22. The switchable sliding sleeve according to claim 21, characterized in that, The second sealing element includes a first sealing ring, two second sealing rings, and two third sealing rings. The two second sealing rings are respectively disposed at both axial ends of the first sealing ring, and the two third sealing rings are respectively disposed at the axial end of the second sealing ring away from the first sealing ring. The first sealing ring is made of rubber, the second sealing ring is made of plastic, and the third sealing ring is made of metal.

23. The switchable sliding sleeve according to claim 22, characterized in that, The cross-section of the first sealing ring is circular; The second sealing ring is composed of two sealing rings, one inner and one outer, with adjacent ends of the two sealing rings connected and the two sealing rings arranged at a certain angle to form an included angle and a sharp angle at opposite ends of the second sealing ring. The included angle of the second sealing ring is fitted into the first sealing ring. The inner part of one end face of the third sealing ring forms an included angle, and the inner part of the included angle is fitted with the sharp corner.

24. The switchable sliding sleeve according to claim 13, characterized in that, The snap-fit ​​assembly also includes a latching component, which is connected to the upper end of the snap-fit ​​assembly; The enclosure assembly also includes a pusher connected to the lower end of the enclosure structure; In the state where the sealing component drives the pusher to move toward the slip assembly, the front end of the pusher can pass between the slip assembly and the central tube assembly and drive the slip assembly to expand radially along the central tube assembly.

25. The switchable sliding sleeve of claim 24, wherein, The slip assembly includes a slip seat and a slip element connected together. The slip seat is sleeved on the central tube assembly. The slip element has a plurality of slips arranged circumferentially along the central tube assembly. The slips are movable radially along the central tube assembly. The lower end of the pusher has a front end slope. The inner side of the slip has a slip slope to abut against the front end slope.

26. The switchable sliding sleeve according to claim 25, characterized in that, Multiple fourth elastic members are compressed between the slip seat and the multiple slips. The fourth elastic members extend radially along the central tube assembly to push the multiple slips to reset and move radially inward along the central tube assembly.

27. The switchable sliding sleeve according to claim 25, characterized in that, The outer radial side of the slip is provided with a plurality of teeth, which are used to engage with the inner wall of the inner cylinder, and the plurality of teeth are continuously arranged along the axial direction of the central tube assembly.

28. The switchable sliding sleeve according to claim 25, characterized in that, The lower outer side of the slip seat is covered with a dustproof cover, which forms a compensation space with the outer wall of the slip seat. The upper end of the sliding sleeve element can be closely attached to the dustproof cover and move along the axial direction of the central tube assembly within the compensation space to seal the gap between the sliding sleeve element and the slip seat.

29. The switchable sliding sleeve according to claim 25, characterized in that, The fifth angle is formed between the projection of the inclined surface of the chuck and the axis of the central tube assembly onto the horizontal plane, and the fifth angle is 13° to 16°. The sixth angle is formed between the projection of the front inclined surface and the axis of the central tube assembly onto the horizontal plane, and the sixth angle is 13° to 16°.

30. The switchable sliding sleeve according to claim 27, characterized in that, The inclined surface of the tooth near the pusher and the projection of the axis of the central tube assembly onto the horizontal plane form a seventh angle, which is 25° to 35°. The inclined surface of the tooth away from the pusher and the projection of the axis of the central tube assembly onto the horizontal plane form an eighth angle, which is 75° to 85°.

31. The switchable sliding sleeve of claim 2, wherein, The sliding sleeve control device further includes: A volumetric cavity assembly is connected to the lower end of the central tube assembly near the bottom of the well. The volumetric cavity assembly includes an air chamber and a fluid channel formed at the lower end of the volumetric cavity assembly. The two ends of the fluid channel are respectively connected to the air chamber and the outer side of the volumetric cavity assembly. A sealing plug is provided inside the fluid channel, and the sealing plug is connected to the inner wall of the fluid channel by a shear pin. When the pressure on the outer side of the volumetric cavity assembly is greater than the shearing force of the shear pin, the sealing plug separates from the inner wall of the fluid channel, allowing the pressurized liquid in the sleeve to enter the air cavity.

32. The switchable sliding sleeve according to claim 31, characterized in that, The volume of the air cavity is 1.5 to 2.5 times the volume of air compressed when the inner cylinder moves between the open and closed positions of the switch slide sleeve.

33. The switchable sliding sleeve according to claim 31, characterized in that, The shearing force of the shear pin is 1.2 to 1.3 times the product of the hydrostatic pressure at the corresponding underground depth and the cross-sectional area of ​​the sealing plug.

34. The switchable sliding sleeve of claim 1, wherein, The elastic claw assembly includes: Multiple first protrusions are provided on the outer side of the elastic claw assembly along the radial outward of the outer shell assembly. The multiple first protrusions are arranged at intervals along the circumference of the elastic claw assembly. The first protrusions can be engaged in the closing locking groove or the opening locking groove to restrict the movement of the inner cylinder.

35. The switchable sliding sleeve according to claim 34, characterized in that, One end of the elastic claw assembly is threadedly connected to the inner cylinder, and the other end of the elastic claw assembly can move along the outer side wall of the inner cylinder, so that the elastic claw assembly can expand or contract radially along the outer shell assembly.

36. The switchable sliding sleeve according to claim 35, characterized in that, The elastic claw assembly further includes a second protrusion formed at the other end of the elastic claw assembly. The second protrusion protrudes radially inward along the outer shell assembly. A limiting groove is formed on the outer side wall of the inner cylinder. The second protrusion is movably embedded in the limiting groove to limit the deformation range of the elastic claw assembly.

37. The switchable sliding sleeve according to claim 34, characterized in that, The step near the opening lock slot of the closing lock slot forms a first switching slope, and the step near the closing lock slot of the opening lock slot forms a second switching slope, so that the elastic claw assembly can retract radially along the first switching slope or the second switching slope. Wherein, the angle formed between the first switching inclined surface and the axial direction of the housing assembly is the ninth angle, which is 25° to 30°, and the angle formed between the second switching inclined surface and the axial direction of the housing assembly is the tenth angle, which is 25° to 30°.

38. The switchable sliding sleeve according to claim 37, characterized in that, The end face of the closing locking groove away from the opening locking groove forms a third switching slope, and the end face of the opening locking groove away from the closing locking groove forms a fourth switching slope, which is used to limit the range of movement of the elastic claw assembly in the closing locking groove or the opening locking groove. The angle formed between the third switching inclined surface and the axial direction of the housing assembly is the eleventh angle, which is 55° to 60°. The angle formed between the fourth switching inclined surface and the axial direction of the housing assembly is the twelfth angle, which is 55° to 60°.

39. The switchable sliding sleeve according to claim 38, characterized in that, The first protrusion has an isosceles trapezoidal cross section, and the angle formed between the side of the first protrusion and the axial direction of the inner cylinder is the thirteenth angle, which is 55° to 60°.

40. The switchable sliding sleeve according to claim 1, characterized in that, An installation step is formed within the fracturing channel, and an external seal is provided on the installation step. The external seal includes an elastic baffle and a one-way element. The one-way element is used to block external fluid from entering. The elastic baffle is connected to the inner wall of the fracturing channel, and the one-way element is disposed between the elastic baffle and the installation step to fix the one-way element within the fracturing channel.

41. The switchable sliding sleeve of claim 40, wherein, The unidirectional element is a soluble sheet, and the center of the soluble sheet has two intersecting fracturing slits to prevent external fluid from entering. The width of the fracturing slits is 0.1 mm to 0.2 mm, and the thickness of the soluble sheet is 0.4 mm to 0.5 mm. The soluble sheet is made of soluble magnesium alloy material.

42. The switchable sliding sleeve according to claim 40, characterized in that, The aspect ratio of the fracturing channel is greater than 3.

5.

43. The switchable sliding sleeve of claim 40, wherein, The total cross-sectional area of ​​the plurality of fracturing channels is 1.1 to 1.5 times the cross-sectional area of ​​the inner cylinder.

44. The switchable sliding sleeve according to claim 1, characterized in that, The inner wall of the outer shell assembly is further provided with a first step and a second step along its own axial direction, and the inner cylinder moves between the first step and the second step along the axial direction of the outer shell assembly. When one end of the inner cylinder abuts against the first step, the elastic claw assembly is embedded in the closing locking groove; when the other end of the inner cylinder abuts against the second step, the elastic claw assembly is embedded in the opening locking groove.

45. The switchable sliding sleeve according to claim 1, characterized in that, The inner wall of the inner cylinder is provided with a first locking groove and a second locking groove in a sequential recessed manner from the wellhead to the bottom of the well along its own axial direction. The first locking groove and the second locking groove are respectively used to lock the first protrusion and the second protrusion formed on the outer peripheral wall of the positioning element.

46. ​​The switchable sliding sleeve according to claim 45, characterized in that, The end face of the first snap-fit ​​groove away from the second snap-fit ​​groove forms a first snap-fit ​​slope, and the end face of the second snap-fit ​​groove away from the first snap-fit ​​groove forms a second snap-fit ​​slope, so that the positioning element can slide into the first snap-fit ​​groove or the second snap-fit ​​groove along the first snap-fit ​​slope or the second snap-fit ​​slope. The angle formed between the first snap-fit ​​inclined surface and the axial direction of the inner cylinder is the fourteenth angle, which is 20° to 25°; the angle formed between the second snap-fit ​​inclined surface and the axial direction of the inner cylinder is the fifteenth angle, which is 25° to 30°.

47. The switchable sliding sleeve according to claim 45, characterized in that, The first snap-fit ​​groove forms a third snap-fit ​​slope near the end face of the second snap-fit ​​groove to confine the first protrusion within the first snap-fit ​​groove, and the second snap-fit ​​groove forms a fourth snap-fit ​​slope near the end face of the first snap-fit ​​groove to confine the second protrusion within the second snap-fit ​​groove. The angle formed between the third snap-fit ​​inclined surface and the axial direction of the inner cylinder is the sixteenth angle, which is 80° to 85°; the angle formed between the fourth snap-fit ​​inclined surface and the axial direction of the inner cylinder is the seventeenth angle, which is 80° to 85°.

48. The switchable sliding sleeve according to claim 44, characterized in that, The inner wall of the outer shell assembly is also recessed with a filter groove, which is located near the second step. A felt ring is provided in the filter groove to filter the liquid between the outer shell assembly and the inner cylinder. The felt ring is composed of a felt mesh with a mesh count of less than 100.

49. The switchable sliding sleeve according to claim 1, characterized in that, The outer shell assembly is connected to the inner cylinder by a pin, which is used to fix the relative position of the inner cylinder and the outer shell assembly during the opening and closing of the sliding sleeve. When the pressurized fluid in the casing pushes the sealing structure, the pin breaks.

50. A method for controlling a switchable sliding sleeve, used to open or close a switchable sliding sleeve as described in any one of claims 1 to 49, characterized in that, The switchable sliding sleeve control method includes: When the switchable sleeve needs to be opened: Multiple switchable sliding sleeves, connected at intervals by casing, are lowered from the wellhead along the inner wall of the wellbore to the section of the wellbore to be fracturing. Cement and cleaning fluid are injected sequentially into the inner channel of the casing to form a cement ring between the casing and the wellbore or between the switchable sliding sleeve and the wellbore. The sliding sleeve control device located at the lower end of the short track of the track-changing element moves down from the wellhead along the channel of the casing to the side of any of the switchable sliding sleeves near the bottom of the well, and the switchable sliding sleeve is in the closed state. The plugging ball moves down from the wellhead along the internal cavity of the central tube assembly to the ball seat, thereby increasing the liquid pressure in the internal cavity of the central tube assembly. The increased liquid pressure is transmitted to the cylinder cavity through the liquid gap, the liquid delivery channel, and the liquid hole in sequence, thereby pushing the sliding sleeve element to move away from the positioning element, and causing the positioning element to expand radially along the central tube assembly. The central tube assembly moves toward the wellhead, and the track-changing element moves from the lower end of the short track to the upper end of the connecting channel, driving the control assembly to move upward until the positioning element is engaged with the inner wall of the inner cylinder. The central tube assembly moves downward toward the bottom of the well, the track-changing element moves downward from the upper end of the connecting channel to the lower end of the long track, and the central tube assembly drives the sealing assembly to move downward and abut against the upper end of the control assembly, causing the sealing structure to expand radially along the central tube assembly to block the inner cylinder, and the slip expands radially along the central tube assembly and engages with the inner wall of the inner cylinder. Pressurized fluid is pumped from the wellhead into the annulus between the casing and the sliding sleeve control device. The pressurized fluid can push the sealing structure and, through the positioning element and the slip, drive the first protrusion connected to the inner cylinder to move from the closed locking groove to the open locking groove, thereby releasing the blockage of the fracturing channel of the outer shell assembly by the inner cylinder, so that the fracturing channel is connected to the internal cavity of the inner cylinder, and the pressurized fluid completes the fracturing operation through the fracturing channel. When the switchable sleeve needs to be closed: The sliding sleeve control device located at the upper end of the connecting channel of the track-changing element moves along the channel of the casing to the side of any of the switchable sliding sleeves near the bottom of the well, and the switchable sliding sleeve is in the open state. The plugging ball moves down from the wellhead along the internal cavity of the central tube assembly to the ball seat, thereby increasing the liquid pressure in the internal cavity of the central tube assembly. The increased liquid pressure is transmitted to the cylinder cavity through the liquid gap, the liquid delivery channel, and the liquid hole in sequence, thereby pushing the sliding sleeve element to move away from the positioning element, and causing the positioning element to expand radially along the central tube assembly. The central tube assembly moves toward the wellhead and drives the control assembly upward until the positioning element engages with the inner wall of the inner cylinder; The central tube assembly continues to move closer to the wellhead, and the central tube assembly drives the first protrusion connected to the inner cylinder to move from the opening locking groove to the closing locking groove, so that the inner cylinder blocks the fracturing channel.

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