An infinite-stage fracturing sliding sleeve

Abstract

The present invention discloses an infinite-stage fracturing sleeve, which belongs to the technical field of downhole operation equipment. The present invention includes an outer cylinder, an inner cylinder, a sliding cylinder, an elastic element and a counting mechanism. The inner cylinder closes the fracturing hole on the outer cylinder. The lower end of the sliding cylinder is provided with an elastic claw. When the number of balls is lower than a preset value, the elastic claw of the sliding cylinder moves in the diameter reduction section and the diameter expansion section in the outer cylinder. In the diameter reduction section, the balls are blocked by the sliding cylinder internal channel. In the diameter expansion section, the elastic claw expands the diameter and releases the balls. When the number of balls is equal to the preset value, the sliding cylinder moves upward and connects the inner cylinder, and then the balls are thrown again. After the balls enter the sliding cylinder, the internal channel thereof is blocked, and the elastic claws can only move in the diameter reduction section and cannot release the balls. After the fracturing sleeve of the present invention is adopted, the fracturing sleeves of each stage can be opened by balls of the same size. There is no size difference between the fracturing sleeves of each stage, so the number of fracturing stages is not limited.

Description

Technical Field

[0001] The invention relates to the technical field of downhole operation equipment, in particular to the technical field of fracturing equipment, and specifically to an infinite-stage fracturing sliding sleeve. Background Art

[0002] Fracturing sleeves are commonly used equipment for staged fracturing. Conventional fracturing sleeves need to be put into the wellhead through the ball when in use. The ball contacts the ball seat to block the passage for the fluid to move to the lower part of the ball seat. At the same time, the wellhead is pressurized to push the ball seat to move, thereby opening the passage on the fracturing string. The fracturing fluid fractures the corresponding reservoir segments along the passage. When multi-stage fracturing is performed, the size of the ball must increase from bottom to top in sequence, so that fracturing can be performed from bottom to top in sequence, but this also limits the number of stages. Summary of the invention

[0003] In view of the above problems, the purpose of the present invention is to provide an infinite-stage fracturing sleeve. When in use, the sizes of the upper and lower fracturing sleeves can be the same, and the fracturing sleeves of each stage can be opened by balls of the same size. Therefore, theoretically, the number of fracturing stages is not limited.

[0004] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0005] An infinite-stage fracturing sliding sleeve, comprising:

[0006] An outer cylinder, wherein the side wall of the outer cylinder is provided with radially arranged fracturing holes; a reduced diameter section and an expanded diameter section are provided in the outer cylinder, wherein the inner diameter of the expanded diameter section is larger than the inner diameter of the reduced diameter section, and the expanded diameter section is located at an end of the reduced diameter section away from the fracturing holes;

[0007] An inner cylinder whose outer wall is sealedly connected to the inner wall of the outer cylinder and is used to close the fracturing hole. The inner cylinder can slide axially along the outer cylinder, and a first connecting portion is provided at one end of the inner cylinder facing the reduced diameter section;

[0008] A sliding cylinder whose outer wall is slidably and sealingly connected to the inner wall of the reduced diameter section, wherein the upper end of the sliding cylinder is provided with a second connection portion that can be connected to the first connection portion, and the lower end is provided with an elastic claw that can move radially; when the elastic claw is located in the reduced diameter section, a sealing ball seat that matches the pitching ball and is used to intercept the pitching ball is formed; when the elastic claw is located in the expanded diameter section, it can expand radially outward so that the size of the middle through hole is larger than the size of the pitching ball;

[0009] An elastic element, used for pushing the sliding cylinder to move toward the inner cylinder;

[0010] The counting mechanism is used to count the number of times the ball passes through the sliding cylinder. When the number of times the ball passes through the sliding cylinder is lower than a preset value, the limit position of the sliding cylinder moving toward the inner cylinder is that the elastic claw is in the reduced diameter section and the second connecting part is below the first connecting part, and the limit position of the sliding cylinder moving away from the inner cylinder is that the elastic claw is below the reduced diameter section. Therefore, after the ball enters the sliding cylinder, it will drive the elastic claw to move from the reduced diameter section to the expanded diameter section, releasing the ball. After the ball is separated from the elastic claw, the elastic claw will move to the reduced diameter section; when the number of times the ball passes through the sliding cylinder is equal to a preset value, the limit position of the sliding cylinder moving toward the inner cylinder is that the elastic claw is in the reduced diameter section and the second connecting part is connected to the first connecting part, so that the inner cylinder can be driven to move through the sliding cylinder, and the limit position of the sliding cylinder moving away from the inner cylinder is that the fracturing hole is opened and the elastic claw is in the reduced diameter section.

[0011] As a specific embodiment of the present invention, the counting mechanism comprises

[0012] A longitudinal groove located on the inner wall of the outer cylinder and arranged along the axial direction of the outer cylinder;

[0013] An inclined groove connecting the middle parts of two adjacent longitudinal grooves;

[0014] A guide rod arranged radially along the sliding cylinder;

[0015] A second elastic element that pushes the guide rod to expand and contract along the radial direction of the sliding cylinder and abut against the inner wall of the longitudinal groove and the inner wall of the inclined groove;

[0016] Among them, by configuring the depth of the grooves at each location of the longitudinal groove and the inclined groove, the guide rod can move from a longitudinal groove along the inclined groove to an adjacent longitudinal groove at a certain stage in the process of the guide rod moving up or down along the outer cylinder, and the guide rod is counted once each time it passes through the inclined groove; the longitudinal groove includes a counting groove and a target groove, the number of the counting grooves is equal to the preset value, all the counting grooves are connected in sequence through the inclined groove, the target groove is connected to the last counting groove through the inclined groove, and the upper end of the target groove is located above the upper end of the counting groove, so that after the guide rod enters the target groove, the sliding cylinder can move upward to the second connecting part and connect with the first connecting part.

[0017] Furthermore, the longitudinal groove includes a first section connected in sequence and a second section located below the first section, the connection point of the first section and the second section is connected to the entrance of the inclined groove, and the outlet of the inclined groove is connected to the middle part of the first section of the adjacent longitudinal groove, wherein, at the connection between the first section, the second section and the entrance of the inclined groove, the groove depth of the first section is less than the groove depth of the second section, and the second section is smoothly connected to the entrance of the inclined groove; at the connection between the outlet of the inclined groove and the first section, the groove depth of the inclined groove is less than the depth of the groove of the first section.

[0018] Further, the first elastic element or the second elastic element is a spring.

[0019] As a specific implementation of the present invention, both the first connection portion and the second connection portion are undercut joints.

[0020] As a specific embodiment of the present invention, the elastic claw is composed of a plurality of L-shaped claws arranged in a circular array. When the elastic claw is located in the diameter reduction section, the side walls of each L-shaped claw abut against each other to form a closed circular ring. When the elastic claw is located in the diameter expansion section, each L-shaped claw moves radially so that its side walls are separated from each other.

[0021] Furthermore, a sealing layer made of elastic material is provided inside the inner wall of the elastic claw.

[0022] As a specific embodiment of the present invention, the inner cylinder is fixed to the outer cylinder by shearable pins.

[0023] As a specific embodiment of the present invention, a limiting boss is provided on the inner wall of the outer cylinder between the reduced diameter sections of the inner cylinder and the outer cylinder, for limiting the extreme position of the movement of the inner cylinder.

[0024] Compared with the prior art, the technical solution of the present invention has the following technical effects:

[0025] (1) The fracturing sleeve of the present invention can count the number of balls that pass through. When the number of balls that pass through reaches a predetermined value, the balls that are thrown in again will block the ball seat like the balls in the conventional fracturing sleeve, so that the fracturing sleeve can be pushed open by pressurizing the fluid through the wellhead. After such a configuration, each stage of the fracturing sleeve can be driven to open by balls of the same size, and there is no size difference between the various stages of the fracturing sleeve, so the number of fracturing stages is not limited.

[0026] (2) The present invention also proposes a new counting mechanism, which can ensure that the guide rod can rotate the sliding cylinder once each time it completes a downward and upward movement through the clever coordination of the groove depth, thereby completing the counting, and the counting is very accurate and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the infinite-stage fracturing sleeve in the initial state;

[0028] Figure 2 It is a schematic diagram of the state in which the sliding cylinder is driven by the balls to descend to the limit position when the number of balls thrown is less than or equal to the number of balls allowed to pass;

[0029] Figure 3 It is a schematic diagram of the state in which the sliding cylinder rises to the limit position after the balls are released when the number of balls thrown is lower than the number of balls allowed to pass;

[0030] Figure 4It is a schematic diagram of the state in which the sliding cylinder rises to the limit position after the balls are released when the number of balls thrown is equal to the number of balls allowed to pass;

[0031] Figure 5 It is a schematic diagram of the state in which the balls drive the sliding cylinder to descend to the limit position when the number of balls thrown is greater than the number of balls allowed to pass;

[0032] Figure 6 is a schematic diagram of the arrangement of the guide rods;

[0033] Figure 7 is a schematic diagram of a longitudinal groove and an inclined groove;

[0034] Figure 8 is a schematic diagram of a connection state between a first connection portion and a second connection portion;

[0035] Fig. 9 is a cross-sectional view of the sliding cylinder;

[0036] The outer cylinder 100, the inner cylinder 200, the sliding cylinder 300, the first elastic element 400, the pitching ball 500, the shearable pin 700,

[0037] Fracturing hole 110, reduced diameter section 120, expanded diameter section 130, annular boss 140, limiting boss 150, first connecting part 210, second connecting part 310, elastic claw 320, sealing layer 330, longitudinal groove 610, inclined groove 620, guide rod 630, first section 611, second section 612, counting groove 650, target groove 660, second elastic element 640. DETAILED DESCRIPTION

[0038] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0039] Example

[0040] Please refer to Figures 1 to 9 , which shows a structural schematic diagram of a specific embodiment of the infinite-stage fracturing sleeve of the present invention.

[0041] The infinite-stage fracturing sleeve of the present invention comprises an outer cylinder 100, an inner cylinder 200, a sliding cylinder 300, a first elastic element 400, a pitching ball 500 and a counting mechanism. The outer cylinder 100 is provided with a through hole arranged along its radial direction, called a fracturing hole 110. The inner wall of the outer cylinder 100 is provided with a reduced diameter section 120 and an expanded diameter section 130, wherein the inner diameter of the expanded diameter section 130 is larger than the inner diameter of the reduced diameter section 120, and the expanded diameter section 130 is located at the end of the reduced diameter section 120 away from the fracturing hole 110, such as Figure 1 As shown, an annular boss 140 is provided on the inner wall of the outer cylinder 100, and the inner wall of the annular boss 140 is the reduced diameter section 120 of the outer cylinder 100, and the expanded diameter section 130 is below the reduced diameter section 120. The outer wall of the inner cylinder 200 is sealedly connected to the inner wall of the outer cylinder 100, and the inner cylinder 200 is used to close the fracturing hole 110, that is, the outer wall of the inner cylinder 200 is directly opposite to the fracturing hole 110, thereby preventing the fluid inside and outside the outer cylinder 100 from communicating through the fracturing hole 110, and the inner cylinder 200 can slide along the axial direction of the outer cylinder 100, thereby opening the fracturing hole 110. A first connecting portion 210 is provided at the lower end of the inner cylinder 200. The outer wall of the sliding cylinder 300 is slidingly and sealingly connected to the inner wall of the reduced diameter section 120. The upper end of the sliding cylinder 300 is provided with a second connection part 310 that can be connected to the first connection part 210. When the first connection part 210 is connected to the second connection part 310, the sliding cylinder 300 can drive the inner cylinder 200 to move axially downward, thereby opening the fracturing hole 110, so that the fluid inside and outside the outer cylinder 100 is connected through the fracturing hole 110. The lower end of the sliding cylinder 300 is provided with an elastic claw 320 that can expand radially to change the inner diameter. When the elastic claw 320 is located in the reduced diameter section 120, a sealing ball seat matching the pitching ball 500 is formed to intercept the pitching ball. After the pitching ball 500 enters the sealing ball seat, it will block the hollow part of the sliding cylinder 300 and block the fluid from flowing downward to the sliding cylinder 300. When the elastic claw 320 is located in the expanded diameter section 130, it can expand radially outward so that the size of the middle through hole is larger than the size of the pitching ball 500, so that the pitching ball 500 can pass normally, that is, the pitching ball 500 can be released. After the release, the fluid can flow downward to the sliding cylinder 300. The first elastic element 400 is used to push the sliding cylinder 300 to move toward the inner cylinder 200 until the elastic claw 320 is located in the reduced diameter section 120. The counting mechanism is used to count the number of times the ball 500 passes through the sliding cylinder 300. When the number of times the ball 500 passes through the sliding cylinder 300 is lower than a preset value (the number of balls allowed to pass through the sliding cylinder in advance), the limit position of the sliding cylinder 300 moving toward the inner cylinder 200 is when the elastic claw 320 is located in the reduced diameter section 120 and the second connecting portion 310 is located below the first connecting portion 210. The limit position of the sliding cylinder 300 moving away from the inner cylinder 200 is when the elastic claw 320 is located below the reduced diameter section 120, that is, located at the expanded diameter section 130. When the number of times the cylinder 300 moves is equal to a preset value, the limit position of the sliding cylinder 300 moving toward the inner cylinder 200 is when the elastic claw 320 is located in the reduced diameter section 120 and the second connecting portion 310 is connected as a whole with the first connecting portion 210, so that the sliding cylinder 300 can drive the inner cylinder 200 to move away from the inner cylinder 200, and the limit position of the sliding cylinder 300 moving away from the inner cylinder 200 is when the fracturing hole 110 is opened and the elastic claw 320 is located in the reduced diameter section 120, so that it can be ensured that the ball 500 is intercepted and the fluid is prevented from flowing under the sliding cylinder 300.

[0042] The workflow of the present invention is as follows Figure 1-5 As shown, Figure 1 It is a schematic diagram of the infinite-stage fracturing sleeve in the initial state. The ball 500 enters the sliding cylinder 300, and the fluid above the ball 500 is pressurized through the wellhead. The ball 500 will drive the sliding cylinder 300 to move downward. Figure 2 It is a schematic diagram of the state in which the balls drive the sliding cylinder to descend to the limit position when the number of balls thrown is less than or equal to the number of balls allowed to pass. Figure 3 This is a schematic diagram of the state in which the sliding cylinder rises to the limit position after the balls are released when the number of balls thrown is lower than the number of balls allowed to pass. Figure 4 This is a schematic diagram of the state in which the sliding cylinder rises to the limit position after the balls are released when the number of balls thrown is equal to the number of balls allowed to pass. Figure 5 It is a schematic diagram of the state in which the balls drive the sliding cylinder to descend to the limit position when the number of balls thrown is greater than the number of balls allowed to pass.

[0043] The counting mechanism is a key point of the present invention. In some embodiments, electromagnetic induction can be used to count. In this embodiment, a mechanical counting mechanism is provided, which can ensure that the sliding cylinder 300 rotates once each time a downward and upward movement is completed, thereby completing the counting, and the counting is very accurate. Figure 6 and Figure 7 As shown, the mechanical counting mechanism of this embodiment includes a longitudinal groove 610 located on the inner wall of the outer cylinder 100 and arranged axially along the outer cylinder 100, an inclined groove 620 connecting the middle parts of two adjacent longitudinal grooves 610, a guide rod 630 arranged radially along the sliding cylinder 300, and a second elastic element 640. The second elastic element 640 pushes the guide rod 630 to expand and contract radially along the outer cylinder 100 and abut against the inner wall of the longitudinal groove 610 and the inner wall of the inclined groove 620. By configuring the depth of the notches at each location of the longitudinal groove 610 and the inclined groove 620, the guide rod 630 can be moved from a longitudinal groove to a certain stage during the process of the guide rod 630 moving up or down along the outer cylinder 100. Move along the inclined groove 620 to the adjacent longitudinal groove 610 toward the groove 610, so that the guide rod 630 is counted once each time it passes through the inclined groove 620; the longitudinal groove 610 includes a counting groove 650 and a target groove 660, wherein the number of the counting grooves 650 is equal to the preset value, and all the counting grooves 650 are connected in sequence through the inclined groove 620, and the target groove 660 is connected to the last counting groove 650 through the inclined groove 620, and the upper end of the target groove 660 is located above the upper end of the counting groove 650, so that after the guide rod 630 enters the target groove 660, the sliding cylinder 300 can move upward to the second connecting part 310 to connect with the first connecting part 210.

[0044] The depth of the notches at each location of the longitudinal groove 610 and the inclined groove 620 can be matched in various forms. For example, in some embodiments, the longitudinal groove 610 includes a first section 611 and a second section 612 located below the first section 611, which are connected in sequence. The connection point of the first section 611 and the second section 612 is connected to the entrance of the inclined groove 620, and the outlet of the inclined groove 620 is connected to the middle of the first section 611 of the adjacent longitudinal groove 610. Among them, at the connection between the first section 611, the second section 612 and the entrance of the inclined groove 620, the groove depth of the first section 611 is less than the groove depth of the second section 612, so that The guide rod 630 can slide smoothly from the first section 611 into the second section 612, but cannot slide from the second section 612 into the first section 611. The second section 612 is smoothly connected to the entrance of the inclined groove 620, so that the guide rod 630 can smoothly enter the inclined groove 620 when moving from the second section 612 to the first section 611. At the same time, at the connection between the exit of the inclined groove 620 and the first section 611, the groove depth of the inclined groove 620 is less than the groove depth of the first section 611, so as to prevent the guide rod 630 from sliding into the inclined groove 620 when moving from the first section 611 to the second section 612.

[0045] In some embodiments, the first connection portion 210 and the second connection portion 310 are both undercut joints, such as Figure 8 As shown, after the second connection part 310 is inserted into the first connection part 210 , the inner cylinder 200 and the sliding cylinder 300 are connected as a whole. When the sliding cylinder 300 is moved axially downward, the sliding cylinder 300 will drive the inner cylinder 200 to move together, thereby opening the fracturing hole 110 .

[0046] In some embodiments, the elastic claw 320 is composed of a plurality of L-shaped claws arranged in a circular array. When the elastic claw 320 is located in the reduced diameter section 120, the side walls of each L-shaped claw abut against each other to form a closed ring. Figure 8 When the elastic claw 320 is located in the diameter expansion section 130, each L-shaped claw moves radially so that its side walls are separated from each other, thereby expanding the size of the internal through hole. In some embodiments, a sealing layer 330 made of elastic material is provided inside the inner wall of the elastic claw 320. The elastic material can be rubber, etc., so that the sealing performance between the pitching ball 500 and the elastic claw 320 can be increased, and the amount of liquid leakage when the elastic claw 320 is located in the diameter reduction section 120 can be reduced.

[0047] In some embodiments, in order to prevent the inner cylinder 200 from accidentally moving, a shearable pin 700 is provided to fix the inner cylinder 200 on the outer cylinder 100. Later, when the sliding cylinder 300 pulls the inner cylinder 200 to move, the shearable pin 700 will be cut off. In addition, in some embodiments, a limiting boss 150 is provided on the inner wall of the outer cylinder 100 between the inner cylinder 200 and the reduced diameter section 120 of the outer cylinder 100, which is used to limit the limit position of the movement of the inner cylinder 200, thereby limiting the limit position of the elastic claw 320 moving away from the direction of the inner cylinder 200 after the first connecting portion 210 is connected to the second connecting portion 310.

[0048] In the present invention, both the first elastic element 400 and the second elastic element 640 may be springs.

[0049] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An infinite-stage fracturing sleeve, characterized in that: include: An outer cylinder, wherein the side wall of the outer cylinder is provided with radially arranged fracturing holes; a reduced diameter section and an expanded diameter section are provided in the outer cylinder, wherein the inner diameter of the expanded diameter section is larger than the inner diameter of the reduced diameter section, and the expanded diameter section is located at an end of the reduced diameter section away from the fracturing holes; An inner cylinder whose outer wall is sealedly connected to the inner wall of the outer cylinder and is used to close the fracturing hole. The inner cylinder can slide axially along the outer cylinder, and a first connecting portion is provided at one end of the inner cylinder facing the reduced diameter section; A sliding cylinder whose outer wall is slidably and sealingly connected to the inner wall of the reduced diameter section, wherein the upper end of the sliding cylinder is provided with a second connection portion that can be connected to the first connection portion, and the lower end is provided with an elastic claw that can move radially; when the elastic claw is located in the reduced diameter section, a sealing ball seat that matches the pitching ball and is used to intercept the pitching ball is formed; when the elastic claw is located in the expanded diameter section, it can expand radially outward so that the size of the middle through hole is larger than the size of the pitching ball; An elastic element, used for pushing the sliding cylinder to move toward the inner cylinder; The counting mechanism is used to count the number of times the ball passes through the sliding cylinder. When the number of times the ball passes through the sliding cylinder is lower than a preset value, the limit position of the sliding cylinder moving toward the inner cylinder is that the elastic claw is in the reduced diameter section and the second connecting part is below the first connecting part, and the limit position of the sliding cylinder moving away from the inner cylinder is that the elastic claw is below the reduced diameter section. Therefore, after the ball enters the sliding cylinder, it will drive the elastic claw to move from the reduced diameter section to the expanded diameter section, releasing the ball. After the ball is separated from the elastic claw, the elastic claw will move to the reduced diameter section; when the number of times the ball passes through the sliding cylinder is equal to a preset value, the limit position of the sliding cylinder moving toward the inner cylinder is that the elastic claw is in the reduced diameter section and the second connecting part is connected to the first connecting part, so that the inner cylinder can be driven to move through the sliding cylinder, and the limit position of the sliding cylinder moving away from the inner cylinder is that the fracturing hole is opened and the elastic claw is in the reduced diameter section.

2. The infinite-stage fracturing sleeve according to claim 1, characterized in that: The counting mechanism comprises A longitudinal groove located on the inner wall of the outer cylinder and arranged along the axial direction of the outer cylinder; An inclined groove connecting the middle parts of two adjacent longitudinal grooves; A guide rod arranged radially along the sliding cylinder; A second elastic element that pushes the guide rod to expand and contract along the radial direction of the sliding cylinder and abut against the inner wall of the longitudinal groove and the inner wall of the inclined groove; Among them, by configuring the depth of the grooves at each location of the longitudinal groove and the inclined groove, the guide rod can move from a longitudinal groove along the inclined groove to an adjacent longitudinal groove at a certain stage in the process of the guide rod moving up or down along the outer cylinder, and the guide rod is counted once each time it passes through the inclined groove; the longitudinal groove includes a counting groove and a target groove, the number of the counting grooves is equal to the preset value, all the counting grooves are connected in sequence through the inclined groove, the target groove is connected to the last counting groove through the inclined groove, and the upper end of the target groove is located above the upper end of the counting groove, so that after the guide rod enters the target groove, the sliding cylinder can move upward to the second connecting part and connect with the first connecting part.

3. The infinite-stage fracturing sleeve according to claim 2, characterized in that: The longitudinal groove includes a first section connected in sequence and a second section located below the first section, the connection point of the first section and the second section is connected to the entrance of the inclined groove, and the outlet of the inclined groove is connected to the middle part of the first section of the adjacent longitudinal groove, wherein, at the connection between the first section, the second section and the entrance of the inclined groove, the groove depth of the first section is less than the groove depth of the second section, and the second section is smoothly connected to the entrance of the inclined groove; at the connection between the outlet of the inclined groove and the first section, the groove depth of the inclined groove is less than the groove depth of the first section.

4. The infinite-stage fracturing sleeve according to claim 2, characterized in that The first elastic element or the second elastic element is a spring.

5. The infinite-stage fracturing sleeve according to claim 1, characterized in that: The first connection portion and the second connection portion are both undercut joints.

6. The infinite-stage fracturing sleeve according to claim 1, characterized in that: The elastic claws are composed of a plurality of L-shaped claws arranged in a circular array. When the elastic claws are located in the diameter reduction section, the side walls of each L-shaped claw abut against each other to form a closed circular ring. When the elastic claws are located in the diameter expansion section, each L-shaped claw moves radially so that its side walls are separated from each other.

7. The infinite-stage fracturing sleeve according to claim 1, characterized in that: A sealing layer made of elastic material is arranged inside the inner wall of the elastic claw.

8. The infinite-stage fracturing sleeve according to claim 1, characterized in that: The inner cylinder is fixed to the outer cylinder by shear pins.

9. The infinite-stage fracturing sleeve according to claim 1, characterized in that: A limiting boss is arranged on the inner wall of the outer cylinder between the reduced diameter sections of the inner cylinder and the outer cylinder, and is used to limit the extreme position of the movement of the inner cylinder.

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