WO-2026092535-A1 - SWITCHABLE SLIDING SLEEVE AND CONTROL METHOD THEREFOR

WO2026092535A1WO 2026092535 A1WO2026092535 A1WO 2026092535A1WO-2026092535-A1

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.

Inventors

GUO, SIWEN
YANG, Yixing
ZHANG, HUAGUANG
LIU, JING
FENG, Fei
HU, ZIJIAN
WANG, JIAXIN
LU, HONGJUN
WANG, SHANGWEI
REN, GUOFU
LI, YAZHOU
Xie, Yonggang
JIANG, ZHIQIANG
LIU, ZHONGNENG
XUE, XIAOWEI

Assignees

中国石油天然气股份有限公司

Dates

Publication Date: 20260507
Application Date: 20251029
Priority Date: 20241029

Claims (20)

A switchable sliding sleeve, characterized in that it comprises: 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.
According to claim 1, the switchable sliding sleeve is characterized in that the sliding sleeve control device includes: a central tube assembly for passing through the casing, the inner cylinder and the inner cavity, the upper end of the central tube assembly extending from the wellhead to the bottom of the well, and the central tube assembly having 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.
The switchable sliding sleeve according to claim 2 is 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.
The switchable sliding sleeve according to claim 3 is 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.
The switchable sliding sleeve according to claim 4 is 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.
The switchable sliding sleeve according to claim 5 is 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°.
The switchable sliding sleeve according to claim 5 is 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.
The switchable sliding sleeve according to claim 7 is 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.
The switchable sliding sleeve according to claim 8 is 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.
The switchable sliding sleeve according to claim 7 is 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.
The switchable sliding sleeve according to claim 10 is 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.
The switchable sliding sleeve according to claim 10 is 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.
The switchable sliding sleeve according to claim 12 is 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.
The switchable sliding sleeve according to claim 13 is 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.
The switchable sliding sleeve according to claim 13 or 14 is 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.
The switchable sliding sleeve according to claim 13 is 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°.
The switchable sliding sleeve according to claim 13 is 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.
The switchable sliding sleeve according to claim 17 is 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.
The switchable sliding sleeve according to claim 18 is 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.
The switchable sliding sleeve according to claim 18 is 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.

Description

Switchable sliding sleeve and its control method Related applications 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 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 The description in this section provides only background information in relation to this disclosure and does not constitute prior art. 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: 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. 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. 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 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. The above-mentioned objectives of this disclosure are mainly achieved through the following technical solutions: On one hand, this disclosure provides a switchable sliding sleeve, comprising: 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. 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. 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. 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. In one specific embodiment, the sliding sleeve control device includes: 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. A seal