CN115992671A - A Differential Pressure Sliding Sleeve with Repeatable Switching - Google Patents

Abstract

The invention relates to a differential pressure type sliding sleeve capable of being repeatedly opened and closed, which comprises a pipe body, an outer sleeve and an inner sleeve, wherein a fracturing hole is formed in the pipe wall, a connecting structure for connecting with a pipe column is arranged at the upper end and the lower end of the pipe body, the outer sleeve is slidably sleeved outside the pipe body and seals the fracturing hole, a pressure cavity communicated with the fracturing hole is arranged between the outer sleeve and the pipe body, the outer sleeve can be hydraulically driven to an avoidance position of the fracturing hole, a latch mechanism is arranged between the outer sleeve and the pipe body, the outer sleeve can be locked after the avoidance position is reached, the inner sleeve is provided with a matching structure for being matched with a tool to be driven by the tool, a blocking position for blocking the fracturing hole and an opening position for avoiding the fracturing hole are arranged in the moving stroke of the inner sleeve, and a limited moment locking mechanism is arranged between the inner sleeve and the pipe body, so that the limited moment locking mechanism can be unlocked after the unlocking force reaches a certain value, and the differential pressure type sliding sleeve can be repeatedly opened and closed.

Description

A Differential Pressure Sliding Sleeve with Repeatable Switching

technical field

The invention relates to a differential pressure sliding sleeve which can be switched repeatedly.

Background technique

Differential pressure sliding sleeve is a completion tool developed for staged completion of horizontal wells. It is usually used in conjunction with completion tools such as ball-pitching fracturing sleeves, staged packers, wellbore isolation valves, and floating shoes. at the toe of the column. The differential pressure sliding sleeve is opened hydraulically. Specifically, the differential pressure sliding sleeve is lowered into the well with the pipe string and the ball-pitching fracturing sleeve in a closed state. The type sliding sleeve is opened to connect the inside and outside of the pipe string, providing a channel for the subsequent pumping of fracturing balls to the ball fracturing sliding sleeve.

At present, the staged completion technology of horizontal wells has been widely applied in China, which has effectively improved the productivity of a single well. For ball-pitching fracturing sleeves, major domestic oil and gas fields and scientific research institutes have successively developed a variety of full-bore repeatable switchable sleeves. The ball-throwing fracturing sleeve, such as the fishing key type, the ball seat drillable type, and the ball seat self-dissolving type, etc., enable the pipe string to form a large diameter, but for the differential pressure sliding sleeve, the traditional pressure is still used at present. Differential sliding sleeves, such as the differential pressure sliding sleeves disclosed in the patent documents with the authorized announcement number CN204782929U, the application publication number CN110080719A and the authorized announcement number CN209212207U. After opening, it cannot be closed again, and the function is single. Affected by this, the pipe string is always in a state of internal and external communication after it is put into production. Any layer above the differential pressure sliding sleeve is tested for layer selection. In addition, once a large amount of water is produced from the gas well, water control and gas production cannot be achieved by quickly closing the differential pressure sliding sleeve.

Contents of the invention

The object of the present invention is to provide a differential pressure sliding sleeve that can be switched repeatedly, so as to solve the technical problem that the differential pressure sliding sleeve cannot be switched repeatedly in the prior art.

In order to achieve the above purpose, the technical solution of the differential pressure sliding sleeve that can be switched repeatedly provided by the present invention is:

A differential pressure sliding sleeve that can be switched repeatedly, comprising a tube body with fracturing holes on the tube wall, the upper and lower ends of the tube body have connection structures for connecting with the pipe string, and the repeatable switch The differential pressure sliding sleeve also includes an outer sleeve and an inner sleeve. The outer sleeve slides outside the pipe and blocks the fracturing hole. The connected pressure chamber enables the outer sleeve to be hydraulically driven to the avoidance position that unblocks the fracturing hole. There is also a latch mechanism between the outer sleeve and the pipe body, so that the outer sleeve can reach the escape position After being locked, the inner sleeve has a matching structure for cooperating with the tool so as to be driven by the tool. In the open position of the fracturing hole, there is a torque-limiting locking mechanism between the inner sleeve and the pipe body to lock the inner sleeve at the upper end of its moving path. The torque-limiting locking mechanism can It is unlocked after reaching a certain value.

The beneficial effect is: the differential pressure sliding sleeve is provided with an outer sleeve, and when the fracturing hole of the differential pressure sliding sleeve needs to be opened, the pressure in the pipe string is increased, and the outer sleeve moves to the avoidance position driven by the pressure , realize the communication between the inner cavity of the pipe string and the outside, and then pump the fracturing balls. After the pipe string is put into production, it is necessary to implement layer selection and repeated fracturing for any layer above the differential pressure sliding sleeve, or it is necessary to When carrying out the layer selection test for any interval, and when a large amount of water is produced in the gas well, the tool can be run into the pipe string through the small-sized coiled tubing to cooperate with the inner sleeve, and the inner sleeve can be driven to the plugging position and open as required. The position is adjusted to realize the repeated opening and closing of the differential pressure sliding sleeve.

As a further improvement, the pipe body includes a central pipe and an upper joint, the connection structure of the upper end of the pipe body is located on the upper joint, the fracturing hole is opened on the central pipe, and the upper joint is connected to the inner cavity of the central pipe. Fitted and connected to the central pipe, the inner cavity of the outer sleeve includes a large-diameter section matched with the central pipe and a small-diameter section matched with the upper joint, and the outer sleeve, the upper joint and the central pipe together enclose the pressure chamber .

The beneficial effect is: the pressure chamber is directly surrounded by the cooperation of the outer sleeve, the upper joint and the central pipe, and the upper end surface of the central pipe itself is utilized, without the need of designing and processing the corresponding structure for the central pipe, so that the pressure of the switch can be repeated. Differential sliding sleeves are easy to manufacture.

As a further improvement, a compression spring is provided in the pressure chamber, one end of the compression spring abuts against the upper end surface of the central tube, and the other end abuts against the step surface at the transition between the large diameter section and the small diameter section of the inner cavity of the outer sleeve Cooperate, there is a torque-limiting locking mechanism between the outer sleeve and the pipe body to lock the outer sleeve in the position of blocking the fracturing hole.

The beneficial effect is that: the compression spring is set to drive the outer sleeve to slide faster relative to the center tube, ensuring that the outer sleeve can be opened reliably and quickly, and the setting of the pin can prevent the outer sleeve from being accidentally opened.

As a further improvement, the upper joint has a stop structure spaced apart from the upper end surface of the center pipe to limit the maximum stroke of the outer sleeve moving upward.

The beneficial effect is that: the stop structure is set to limit the maximum stroke of the outer sleeve moving up, so as to prevent the sliding distance of the outer sleeve from being too large when the outer sleeve slides to the avoidance position, resulting in failure of the latching mechanism to cooperate with the latch.

As a further improvement, the outer sleeve fits with the central pipe in a gap, and the gap between the two forms a channel connecting the fracturing hole and the pressure chamber, and the upper and lower ends of the outer sleeve are respectively sealed and fitted with the upper joint and the central pipe .

The beneficial effect is: the channel connecting the fracturing hole and the pressure chamber is directly surrounded by the clearance fit between the outer sleeve and the central pipe, so that the differential pressure sliding sleeve that can be switched repeatedly is easy to manufacture, and at the same time, the gap between the outer sleeve and the inner tube is reduced. The friction between the center tubes ensures that the outer sleeve can be opened stably and reliably.

As a further improvement, the torque-limiting locking mechanism between the inner sleeve and the tube body is composed of snap rings and snap ring matching grooves respectively arranged on the tube body and the inner sleeve, and the snap ring matching slots are located in the inner sleeve The groove wall on one side of the moving direction of the barrel is a chute wall, so that the torque limiting locking mechanism can be unlocked after the unlocking force reaches a certain value.

The beneficial effect is that the torque-limiting locking mechanism of the circlip and the circlip combined with the trough has a simple structure and is easy to obtain materials, so that the differential pressure sliding sleeve that can be switched repeatedly is easy to manufacture.

As a further improvement, the matching structure is an annular groove provided on the inner wall of the inner sleeve, and the annular groove is hooked and matched with the corresponding tool through the groove wall in the vertical direction.

The beneficial effect is that the ring groove structure is convenient for processing and manufacturing, therefore, the use of the ring groove structure for the matching structure makes the inner sleeve easy to manufacture, and further makes the differential pressure sliding sleeve that can be switched repeatedly easy to manufacture.

As a further improvement, the differential pressure sliding sleeve that can be switched repeatedly further includes a torque-limiting locking mechanism capable of locking the inner sleeve at the lower end of its moving path.

The beneficial effect is that: the position of the inner sleeve is limited by the torque-limiting locking structure, so that the inner sleeve is prevented from opening or closing the fracturing hole by mistake.

As a further improvement, the pipe body includes a central pipe and an upper joint, the connection structure of the upper end of the pipe body is located on the upper joint, the fracturing hole is opened on the central pipe, and the upper joint is connected to the inner cavity of the central pipe. Fittingly connected to the central pipe, the lower end of the upper joint is limited to the position limit of the upward movement of the inner sleeve.

The beneficial effect is: the upper joint is used to limit the limit position of the inner sleeve, and the lower end surface of the upper joint is used, and there is no need to design a limit structure in the pipe body to limit the inner sleeve, so as to ensure the pressure of the repeatable switch. The differential sleeve has the simplest possible construction.

As a further improvement, the pipe body also includes a lower joint, the connection structure of the lower end of the pipe body is located on the lower joint, and the lower joint is connected to the central pipe in cooperation with the inner cavity of the central pipe, and the upper end of the lower joint Limit the position facing the downward movement of the inner sleeve.

The beneficial effect is: the limit position of the inner sleeve is limited by the cooperation of the upper joint and the lower joint, the lower end surface of the upper joint and the upper end surface of the lower joint are used, and there is no need to design a limit position of the inner sleeve in the pipe body The limit structure realizes the reliable position adjustment of the inner sleeve and at the same time ensures that the differential pressure sliding sleeve that can be switched repeatedly has a structure as simple as possible.

Description of drawings

Fig. 1 is a structural schematic diagram of embodiment 1 of a differential pressure sliding sleeve that can be switched repeatedly in the present invention;

Figure 2 is a partial enlarged view of A in Figure 1;

Fig. 3 is a partial enlarged view of place B in Fig. 1;

Fig. 4 is a structural schematic diagram of the initial state of the differential pressure sliding sleeve embodiment 1 that can be switched repeatedly in the present invention;

Fig. 5 is a structural schematic diagram of the differential pressure sliding sleeve embodiment 1 that can be switched repeatedly in the present invention after it is opened by pressure;

Fig. 6 is a structural schematic diagram of the differential pressure sliding sleeve embodiment 1 that can be switched repeatedly in the present invention after it is opened by pressure and then closed by the inner sleeve;

Fig. 7 is a structural schematic diagram of the embodiment 1 of the differential pressure sliding sleeve that can be switched repeatedly in the present invention after being closed by the inner sleeve and then opened again;

Explanation of reference signs:

1. Central tube; 2. Upper joint; 3. Lower joint; 4. Fracturing hole; 5. Outer sleeve; 6. Seal ring; 7. Compression spring; , inner sleeve; 11, circlip; 12, upper circlip groove; 13, lower circlip groove; 14, upper ring groove; 15, lower ring groove; 16, upper sealing ring; 17, lower sealing ring; 18, Shear pins.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, and are not intended to limit the present invention, that is, the described embodiments are only some of the embodiments of the present invention, but not all of the embodiments. The components of the embodiments of the invention generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations.

Accordingly, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts belong to the protection scope of the present invention.

It should be noted that relative terms such as the terms "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any relationship between these entities or operations. There is no such actual relationship or order between them. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or device. Without further limitations, an element defined by the phrase "comprising a..." does not exclude a process, method comprising said element.

In the description of the present invention, unless otherwise clearly stipulated and limited, the terms "installation", "connection" and "connection" that may appear should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection, Or integrally connected; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary, and it may be the internal communication of two components. Those skilled in the art can understand the specific meanings of the above terms in the present invention through specific situations.

In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the term "has" that may appear should be understood in a broad sense, for example, the object of "has" can be a part of the ontology, or it can be It is arranged separately from the main body and connected to the main body. The connection can be detachable or non-detachable. Those skilled in the art can understand the specific meanings of the above terms in the present invention through specific situations.

Below in conjunction with embodiment the present invention is described in further detail.

Specific embodiment 1 of the differential pressure sliding sleeve that can be switched repeatedly provided by the present invention:

As shown in Figure 1, the pressure differential sliding sleeve that can be switched repeatedly includes a pipe body. Specifically, the pipe body includes a central pipe 1 and an upper joint 2 and a lower joint 3 respectively connected to the upper and lower ends of the central pipe 1. The central pipe 1 Both upper and lower ends have internal threads, and the upper joint 2 and the lower joint 3 cooperate with the internal threads of the central pipe 1 to realize screw connection with the central pipe 1 . The upper end of the upper joint 2 has an internal thread, and correspondingly, the lower end of the lower joint 3 has an external thread. The internal thread at the upper end of the upper joint 2 and the external thread at the lower end of the lower joint 3 serve as the connection structure of the pipe body so that the differential pressure sliding sleeve can be connected in series. in the column.

The central pipe 1 is provided with a fracturing hole 4. As shown in FIG. 1 , an outer sleeve 5 is provided on the outside of the pipe body. In the initial state, the outer sleeve 5 blocks the fracturing hole 4 . Specifically, the inner cavity of the outer sleeve 5 is divided into a large-diameter section and a small-diameter section, the large-diameter section cooperates with the outer peripheral surface of the central pipe 1, and the small-diameter section cooperates with the outer peripheral surface of the upper joint 2. Since the upper joint 2 cooperates with the central pipe 1 The outer diameter of one section is smaller than the outer diameter of the central pipe 1, and the upper end surface of the outer sleeve 5 cooperates with the upper joint 2 and the central pipe 3 to enclose a pressure chamber. The annular space between the sleeve 5 and the central pipe 1 communicates the pressure chamber with the fracturing hole 4. At the same time, in order to realize the sealing of the sliding sleeve, the upper end and the lower end of the outer sleeve 5 are respectively connected to the upper joint 2 and the central joint 2 through the sealing ring 6. The tube 1 is sealed and fit, so that when the sliding sleeve needs to be opened, the pressure in the inner cavity of the tube is increased, and the hydraulic pressure in the inner cavity of the tube passes through the fracturing hole 4, the annular space between the outer sleeve 5 and the central tube 1 to make the pressure in the pressure cavity As the pressure increases, the high pressure drives the outer sleeve 5 to move upward to the avoidance position for unblocking the fracturing hole 4 .

In this embodiment, in order to enable the outer sleeve 5 to move to the avoidance position reliably and quickly during the opening operation, a compression spring 7 is also provided in the pressure chamber. Specifically, the lower end of the compression spring 7 is pressed against the top of the central tube 1 On the end face, the upper end abuts against the stepped surface of the transition between the large-diameter section and the small-diameter section of the inner cavity of the outer sleeve 1. At the same time, the lower end of the outer sleeve 5 and the central tube 1 are pinned with shear pins 18 to ensure that the outer sleeve The sleeve 5 can be stably maintained at the position of sealing the fracturing hole 4 before the opening operation. Furthermore, there is a stop structure on the upper joint 2. In this embodiment, the stop structure is a stepped surface provided on the upper joint 2. Through the cooperation of the stop structure and the upper end surface of the outer sleeve 5, the upper end surface of the outer sleeve 5 can be aligned. In other embodiments, the stop structure can also be a protrusion provided on the upper joint 2, such as a stop pin, a bump, and the like. In addition, in order to ensure that the outer sleeve 5 can be stably maintained in the avoidance position after opening, a latch mechanism is also provided between the outer sleeve 5 and the central tube 1. Specifically, in this embodiment, as shown in FIG. 2 , The latch mechanism includes a backstop ring 8 arranged on the outer sleeve 5 and a backstop tooth 9 arranged on the central tube 1. When the outer sleeve 5 moves to the avoidance position, the backstop tooth 9 cooperates with the backstop ring 8 to The outer sleeve 5 is locked in the avoidance position.

In order to achieve repeatable opening and closing, an inner sleeve 10 is also provided in the tube body, as shown in Fig. The sleeve 10 can cooperate with the corresponding tool and can move up and down under the drive of the tool. In this embodiment, in the initial state, the inner sleeve 10 is located below the fracturing hole 4 and is in the open position. When it is necessary to use the inner sleeve 10 When closing the fracturing hole 4, the inner sleeve 10 is lifted up through the cooperation of the tool and the matching structure. In order to maintain the position of the inner sleeve 10, a limited torque locking mechanism is provided between the inner sleeve 10 and the central tube 1. Specifically, the torque limiting locking mechanism includes a snap spring 11 arranged on the inner sleeve 10, and as shown in FIG. 2 shows the upper snap ring groove 12 set on the upper end of the central tube 1, when the inner sleeve 10 moves up to the blocking position, the snap ring 11 can cooperate with the upper snap ring groove 12 to lock the position of the inner sleeve 10 , the lower groove wall of the upper circlip groove 12 is an inclined plane, so that the torque limiting locking mechanism can be unlocked. When the downward thrust applied to the inner sleeve 10 reaches a certain value, the torque limiting locking mechanism can be released so that the inner sleeve 10 can be driven to move downward to the open position. In this embodiment, in order to ensure that the outer sleeve 10 can be stably in the open position, the lower end of the central tube 1 is provided with a lower snap ring groove 13. When the inner sleeve 10 is in the open position, the snap ring 11 and the lower snap ring slot 13 Cooperate, the inner sleeve 10 is locked in the open position, and the upper groove wall of the lower circlip groove 13 is a slope, so that the torque limiting locking mechanism formed by the circlip 11 and the lower circlip groove 13 can be unlocked.

In this embodiment, the tool used to drive the inner sleeve 10 is a two-way start-up sliding sleeve switch tool disclosed in the patent document CN203362115U. Correspondingly, as shown in Figure 3, the matching structure is set inside The upper ring groove 14 at the upper end of the inner wall of the sleeve 10 and the lower ring groove 15 at the lower end. Wherein, the angle between the upper groove wall and the groove bottom of the upper ring groove 14 is 90°, and the angle between the lower groove wall and the groove bottom is 150°, so that the tool can be aligned with the upper groove of the upper ring groove 14 when moving upward. The groove wall is hooked and fitted, and when moving downward, it can slip out from the upper ring groove 14 under the guidance of the lower groove wall. Opposite to the upper ring groove 14, the angle between the upper groove wall and the groove bottom of the lower ring groove 15 is 150°, and the angle between the lower groove wall and the groove bottom is 90°.

In order to seal the fracturing hole 4, an upper sealing ring 16 and a lower sealing ring 17 are also provided on the outer wall of the inner sleeve 10. After the inner sleeve 10 moves to the sealing position, the upper sealing ring 16 and the lower sealing ring 17 Located on the upper and lower sides of the fracturing hole 4, when the inner sleeve 10 is in the open position, the upper sealing ring 16 and the lower sealing ring 17 are respectively located on the upper and lower sides of the fracturing hole 4.

In specific use, the pressure differential sliding sleeve that can be switched repeatedly in the present invention is used in conjunction with the ball-pitching fracturing sliding sleeve that can realize full diameter. Specifically, in the initial state, as shown in Figure 4, the outer sleeve 5 is in the sealing position. When the position of the fracturing hole 4 is blocked, the inner sleeve 10 is in the open position. When the fracturing ball needs to be pumped, the pressure in the pipe string is increased, so that the pressure in the pressure chamber increases, and the outer sleeve 5 is driven to move upward to avoid position, as shown in Figure 5, to realize the opening of the sliding sleeve, and then the pumping operation of the fracturing ball can be carried out. The coiled tubing lowers the tool matched with the inner sleeve 10 into the pipe string, uses the tool to apply force to the inner sleeve 10, overcomes the cooperation between the circlip 11 and the lower circlip groove 13, and pulls the inner sleeve 10 to the blocking position. As shown in FIG. 6 , until the retaining spring 11 fits with the upper retaining ring groove 12 , the lower end of the upper joint 2 limits the limit stroke of the upward movement of the inner sleeve 10 . When it is necessary to open the sliding sleeve again, use a tool to cooperate with the lower groove 15 to push the inner sleeve 10 to the open position, as shown in Figure 7, the upper end of the lower joint 3 faces the limit of the downward movement of the inner sleeve 10 The itinerary is limited.

For the up-down direction in the above embodiments, only the structure of the sliding sleeve is described with the sliding sleeve in a vertical state, so as to clarify the movement form of the outer sleeve and the inner sleeve relative to the central tube.

The specific embodiment 2 of the pressure differential sliding sleeve that can be switched repeatedly provided by the present invention is mainly different from the embodiment 1 in that in the embodiment 1, the upper joint, the outer sleeve and the central pipe cooperate to form a pressure chamber, In this embodiment, the upper end of the central tube is designed to be a large-diameter section and a small-diameter section, and the upper end is a small-diameter section, the large-diameter section is located below the small-diameter section, and the small-diameter section of the inner cavity of the outer sleeve cooperates with the small-diameter section of the central tube. The large-diameter section cooperates with the large-diameter section of the central pipe, and the central pipe and the outer sleeve directly form a pressure chamber.

The specific embodiment 3 of the differential pressure sliding sleeve that can be switched repeatedly provided by the present invention differs from the embodiment 1 mainly in that: in this embodiment, the clamp spring in the torque limiting locking mechanism is arranged on the central tube, and the clamp The spring groove is arranged on the inner sleeve, and correspondingly, two retaining springs are arranged at the upper and lower ends of the central tube.

The specific embodiment 4 of the differential pressure sliding sleeve that can be switched repeatedly provided by the present invention differs from the embodiment 1 mainly in that: in this embodiment, the torque limiting locking mechanism is a spring steel ball locking mechanism, specifically, A blind hole is set on the inner sleeve along its radial direction, and the steel ball is installed in the blind hole through a spring. Correspondingly, a matching groove is set on the tube wall of the central tube. Before reaching the fitting groove, the steel ball is in the blind hole The spring is internally compressed, and when the spring reaches the position aligned with the matching groove, part of it enters into the matching groove under the pushing action of the spring to realize the locking of the position of the inner sleeve.

The specific embodiment 5 of the pressure differential sliding sleeve that can be switched repeatedly provided by the present invention differs from the embodiment 1 mainly in that in this embodiment, the inner sleeve cooperates with the tool to drive the inner sleeve to move upward. The structure is the lower end surface of the inner sleeve, based on which, when the inner sleeve is in the open position, the lower joint is spaced apart from the inner sleeve.

Finally, it should be noted that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it is still The technical solutions described in the foregoing embodiments can be modified without creative effort, or equivalent replacements can be made to some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. The utility model provides a but repeatedly opened and closed's differential sliding sleeve, has offered the body of fracturing hole (4) on the pipe wall, the upper and lower both ends of body have the connection structure who is used for being connected with the tubular column, characterized by, repeatedly opened and closed's differential sliding sleeve still includes outer sleeve and inner sleeve, and outer sleeve slip cap is established outside the pipe body and shutoff fracturing hole (4), have between outer sleeve (5) and the body with the pressure chamber of fracturing hole (4) intercommunication for outer sleeve (5) can be by hydraulic drive to the dodging position of releasing fracturing hole (4) shutoff, still have latch mechanism between outer sleeve (5) and the body, make outer sleeve (5) can be by the locking position after reaching the dodging position, inner sleeve (10) have be used for with the cooperation of instrument in order to be driven by the instrument cooperation structure, inner sleeve (10) have shutoff in its travel fracturing hole (4) shutoff position and dodge the opening position of fracturing hole (4), have between inner sleeve (10) and the body and have inner sleeve locking torque limiting mechanism to be able to reach the unlocking torque value at its upper end after it is locked.

2. The pressure difference type sliding sleeve capable of repeatedly opening and closing according to claim 1, wherein the pipe body comprises a central pipe (1) and an upper joint (2), a connecting structure at the upper end of the pipe body is located on the upper joint (2), the fracturing hole (4) is formed in the central pipe (1), the upper joint (2) is matched with an inner cavity of the central pipe (1) to be connected to the central pipe (1), the inner cavity of the outer sleeve (5) comprises a large-diameter section matched with the central pipe (1) and a small-diameter section matched with the upper joint (2), and the outer sleeve (5), the upper joint (2) and the central pipe (1) jointly enclose the pressure cavity.

3. The pressure difference type sliding sleeve capable of repeatedly opening and closing according to claim 2, wherein a pressure spring (7) is arranged in the pressure cavity, one end of the pressure spring (7) is propped against the upper end face of the central tube (1), the other end of the pressure spring is propped against and matched with a step face at the transition part of the large-diameter section and the small-diameter section of the inner cavity of the central tube (1), and a torque limiting locking mechanism for locking the outer sleeve (5) at the position for plugging the fracturing hole (4) is arranged between the outer sleeve (5) and the tube body.

4. The pressure difference type sliding sleeve capable of repeatedly opening and closing according to claim 2, wherein the upper joint (2) is provided with a stop structure which is arranged at intervals with the upper end face of the central tube (1) so as to limit the maximum travel of the upper moving of the outer sleeve (5).

5. The pressure difference type sliding sleeve capable of being repeatedly opened and closed according to claim 2, wherein the outer sleeve (5) is in clearance fit with the central tube (1), a gap between the outer sleeve and the central tube forms a channel for communicating the fracturing hole (4) and the pressure cavity, and the upper end and the lower end of the outer sleeve (5) are respectively in sealing fit with the upper joint (2) and the central tube (1).

6. The pressure differential sliding sleeve capable of being repeatedly opened and closed according to any one of claims 1 to 5, wherein the moment limiting locking mechanism is composed of a clamp spring (11) and a clamp spring matching groove which are respectively arranged on the pipe body and the inner sleeve (10), and the groove wall of the clamp spring matching groove positioned on one side of the inner sleeve (10) in the moving direction is a chute wall, so that the moment limiting locking mechanism can be unlocked after the unlocking force reaches a certain value.

7. The pressure difference type sliding sleeve capable of being repeatedly opened and closed according to any one of claims 1 to 5, wherein the matching structure is a ring groove formed on the inner wall of the inner sleeve (10), and the ring groove is hooked and matched with a corresponding tool through the groove wall in the upper and lower directions.

8. The pressure differential sliding sleeve capable of being repeatedly opened and closed according to any one of claims 1 to 5, wherein the pressure differential sliding sleeve capable of being repeatedly opened and closed further comprises a moment limiting locking mechanism capable of locking the inner sleeve (10) at the lower end of the moving path.

9. The pressure difference type sliding sleeve capable of repeatedly opening and closing according to claim 1, wherein the pipe body comprises a central pipe (1) and an upper joint (2), a connecting structure at the upper end of the pipe body is located on the upper joint (2), the fracturing hole (4) is formed in the central pipe (1), the upper joint (2) is connected to the central pipe (1) in a matched mode with an inner cavity of the central pipe (1), and the lower end of the upper joint (2) limits the upward moving position limit of the inner sleeve (10).

10. The pressure difference type sliding sleeve capable of repeatedly opening and closing according to claim 9, wherein the pipe body further comprises a lower joint (3), the connecting structure of the lower end of the pipe body is located on the lower joint (3), the lower joint (3) is connected to the central pipe (1) in a matched mode with the inner cavity of the central pipe (1), and the upper end of the lower joint (3) limits the downward moving position limit of the inner sleeve (10).

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