Infinitely actuable sliding sleeve

Abstract

An infinitely actuable sliding sleeve, comprising: an outer shaft sleeve (100) vertically arranged in a well, a bypass mandrel (200) fixed in the outer shaft sleeve (100) and located at the upper portion of the outer shaft sleeve (100), and a flow activation assembly (300) movably arranged in the outer shaft sleeve, wherein the lower side of the outer shaft sleeve (100) is provided with a communication hole (110) penetrating through the wall thickness of the outer shaft sleeve (100); the bypass mandrel (200) and the outer shaft sleeve (100) define an upper bypass area (500), and a side wall of the bypass mandrel (200) is provided with a bypass hole (210) penetrating through the wall thickness of the bypass mandrel (200); the flow activation assembly (300) and the outer shaft sleeve (100) define a lower bypass area (600); the flow activation assembly (300) can move in the axial direction of the outer shaft sleeve (100) under the action of a fluid pressure difference and, in an initial state, extends into the upper bypass area (500) and blocks the bypass hole (210), such that the lower bypass area (600) is not in communication with the communication hole (110); and in an activated state, the flow activation assembly (300) extends out of the upper bypass area (500) and opens the bypass hole (210), such that the lower bypass area (600) is in communication with the communication hole (110). The sliding sleeve avoids the problem of dropped balls blocking central bore channels, and can be infinitely cyclically used during switching between the initial state and the activated state.

Description

An infinitely reusable sliding sleeve

[0001] This application claims priority to Chinese Patent Application No. 202411894732.X, filed on December 20, 2024, entitled “An Infinitely Activated Sliding Sleeve”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of oil drilling technology, and in particular to an infinitely reactivatable sliding sleeve. Background Technology

[0003] Sliding sleeves are an important component of drilling tools, typically used to control the flow of drilling fluids or other fluids. By opening or closing the sliding sleeve, the flow path of the fluid can be altered, thereby controlling downhole pressure and flow rate.

[0004] In existing drilling and workover processes, ball-drop sleeves are typically used to control and activate the tool. However, ball-drop sleeves are usually designed for single use and cannot be reused to activate the tool. Furthermore, once the ball is deployed into the well, it is difficult to retrieve, which can affect subsequent downhole operations or tool operation. Summary of the Invention

[0005] This application provides an unlimited activation of the sliding sleeve to solve the problem in the prior art that the sliding sleeve cannot be reused and may block the central water eye channel, affecting subsequent operations.

[0006] This application provides an infinitely activatable sliding sleeve for lowering into a drilling well, comprising: an outer sleeve, vertically disposed within the drilling well; a connecting hole on the lower side of the outer sleeve, the connecting hole penetrating the wall thickness of the outer sleeve; a bypass mandrel, fixed inside the outer sleeve and located at the upper part of the outer sleeve, the bypass mandrel and the outer sleeve forming an upper bypass area; a bypass hole on the side wall of the bypass mandrel, the bypass hole penetrating the wall thickness of the bypass mandrel; and a flow activation assembly, movably disposed inside the outer sleeve, the flow activation assembly and the outer sleeve forming a lower bypass area; wherein, the flow activation assembly can move axially along the outer sleeve under the action of fluid pressure difference, and has an initial state and an activated state; in the initial state, the flow activation assembly extends into the upper bypass area and blocks the bypass hole, the lower bypass area and the connecting hole are not connected; in the activated state, the flow activation assembly extends out of the upper bypass area and opens the bypass hole, the lower bypass area and the connecting hole are connected.

[0007] In one possible implementation, the flow activation assembly includes: a guide mandrel movably disposed within an outer bushing; the bottom end of the guide mandrel has a throttling section, the flow area of ​​which is smaller than the flow area of ​​other parts of the guide mandrel; and a limiting track is provided on the outer wall of the guide mandrel; a guide member passes through the outer bushing, extends into the limiting track, and slides along the limiting track; wherein, when the guide member is located at the lower limiting end of the limiting track, the flow activation assembly is in an initial state; when the guide member is located at the upper limiting end of the limiting track, the flow activation assembly is in an activated state.

[0008] In one possible implementation, the limiting track further includes a middle limiting end located between the lower limiting end and the upper limiting end; when the guide is located at the middle limiting end, the flow activation assembly still blocks the bypass hole.

[0009] In one possible implementation, the limiting track is provided with a plurality of lower limiting ends, at least two middle limiting ends and at least two upper limiting ends in sequence along the circumference. The middle limiting ends and the upper limiting ends are arranged alternately in sequence, and each middle limiting end corresponds to a lower limiting end and each upper limiting end also corresponds to a lower limiting end. The adjacent middle limiting ends and upper limiting ends, as well as the lower limiting ends corresponding to them, are connected by a track changing channel.

[0010] In one possible implementation, the track-changing channel includes a first channel and a second channel. The two ends of the first channel are respectively connected to a lower limit end and a corresponding middle limit end or upper limit end. The two ends of the second channel are respectively connected to another lower limit end and a corresponding upper limit end or middle limit end. The first channel and the second channel have a common vertical section. The first channel also includes an upwardly extending vertical section and a first upwardly inclined section extending upward from the upper end of the common vertical section, and a downwardly extending vertical section and a first downwardly inclined section extending downward from the lower end of the common vertical section. The second channel also includes a second upwardly inclined section and an upper connecting vertical section extending upward from the upper end of the common vertical section, and a second downwardly inclined section and a lower connecting vertical section extending downward from the lower end of the common vertical section.

[0011] In one possible implementation, the variable track spindle includes a first shaft segment, a second shaft segment, and a third shaft segment connected in sequence, with the shaft diameters of the first shaft segment, the second shaft segment, and the third shaft segment decreasing in sequence, and a limiting rail is disposed on the first shaft segment; the flow activation assembly also includes a first elastic element, which is sleeved on the second shaft segment; the upper end of the first elastic element abuts against the first shaft segment, and the lower end of the first elastic element abuts against the inner wall of the outer bushing.

[0012] In one possible implementation, the third shaft segment has a flow channel hole for fluid to enter and exit, and the flow channel hole is close to the second shaft segment.

[0013] In one possible implementation, the flow activation assembly further includes a fixed base and a fixing member; the lower end of the first elastic member is connected to the fixed base, and the fixed base abuts against the inner wall of the outer bushing; and the fixed base is connected to the variable track spindle via the fixing member.

[0014] In one possible implementation, the infinitely activating sliding sleeve further includes: an outer ring empty trigger assembly connected inside the outer bushing and located at the lower part of the outer bushing; the outer ring empty trigger assembly is axially extendable along the outer bushing; and the outer ring empty trigger assembly extends into the lower bypass area; in the initial state, the outer ring empty trigger assembly blocks the connecting hole; in the activated state, the outer ring empty trigger assembly opens the connecting hole, and the lower bypass area communicates with the connecting hole.

[0015] In one possible implementation, the outer ring air trigger assembly includes a sleeve, a connecting fastener, and a second elastic member; the connecting fastener is fixed to the lower end of the outer bushing, the second elastic member is connected between the connecting fastener and the sleeve, and the upper end of the sleeve abuts against the inner wall of the outer bushing.

[0016] The unlimited activation sliding sleeve provided in this application embodiment is used for lowering into the drilling well. The unlimited activation sliding sleeve includes: an outer sleeve vertically disposed within the drilling well; a bypass mandrel fixed within the outer sleeve and located at the upper part of the outer sleeve; and a flow activation assembly movably disposed within the outer sleeve. A connecting hole penetrating the wall thickness of the outer sleeve is formed on the lower side of the outer sleeve. The bypass mandrel and the outer sleeve form an upper bypass area, and a bypass hole penetrating the wall thickness of the bypass mandrel is formed on the side wall of the bypass mandrel. The flow activation assembly and the outer sleeve form a lower bypass area.

[0017] The flow activation assembly can move axially along the outer bushing under the action of fluid pressure difference, and has an initial state and an activated state. In the initial state, the flow activation assembly extends into the upper bypass area and blocks the bypass hole, while the lower bypass area and the connecting hole are not connected. In the activated state, the flow activation assembly extends out of the upper bypass area and opens the bypass hole, while the lower bypass area and the connecting hole are connected.

[0018] By installing a flow activation assembly that can move axially along the outer bushing within the outer bushing, the flow activation assembly can be triggered to move downwards under the action of fluid pressure difference. This opens the bypass orifice that was originally blocked by the flow activation assembly, allowing fluid inside the bypass mandrel to flow in the upper bypass zone. At this time, the pressure in the upper bypass zone is equal to the pressure in the internal flow channel of the bypass mandrel. Simultaneously, the lower bypass zone enclosed by the flow activation assembly and the outer bushing will connect with the connecting hole on the outer bushing that communicates with the outside, thus creating a certain pressure difference between the lower and upper bypass zones, keeping the bypass orifice in the open state.

[0019] After the fluid pressure difference is lost, the flow activation assembly returns to its initial state, re-enters the upper bypass zone and blocks the bypass hole, while the lower bypass zone is also disconnected from the connecting hole. This configuration avoids the problem of blockage of the central water channel that might occur when using the ball-throwing sleeve, thus preventing subsequent operations from being affected, and achieves the effect of infinite recycling of the sleeve. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 is a partial cross-sectional view of the sliding sleeve with unlimited activation provided in the embodiment of this application in the initial state;

[0022] Figure 2 is an overall cross-sectional view of the sliding sleeve with unlimited activation provided in the embodiment of this application in the initial state;

[0023] Figure 3 is a partial cross-sectional view of the sliding sleeve in the activated state, provided in an embodiment of this application;

[0024] Figure 4 is a schematic diagram of the unfolding of the limiting track provided in an embodiment of this application;

[0025] Figure 5 is a partially enlarged schematic diagram of the first channel in Figure 4;

[0026] Figure 6 is a partially enlarged schematic diagram of the second channel in Figure 4;

[0027] Figure 7 is a schematic diagram of the structure of the track-changing mandrel provided in the embodiment of this application;

[0028] Figure 8 is a schematic diagram of the flow activation assembly provided in an embodiment of this application;

[0029] Figure 9 is a schematic diagram of the structure of the outer bushing provided in the embodiment of this application.

[0030] Explanation of reference numerals in the attached drawings: 100-Outer bushing; 110-Connecting hole; 120-First shoulder; 130-Second shoulder; 140-Rail screw hole; 150-First thread; 160-Second thread; 200-Bypass mandrel; 210-Bypass hole; 300-Flow activation assembly; 310-Changing mandrel; 3101-First shaft section; 3102-Second shaft section; 3103-Third shaft section; 3104-Flow channel hole; 3105-Shear pin hole; 311-Throttling section; 312-Limiting rail; 313-Upper limit end; 314-Middle limit end; 315-Lower limit end; 316-Changing channel; 3161-First channel; 31611-Upper extended vertical section; 31612-First upper inclined section; 31613-Lower extended vertical section; 31614-First lower inclined section; 3162 - Second channel; 31621 - Second upper inclined section; 31622 - Upper connecting vertical section; 31623 - Second lower inclined section; 31624 - Lower connecting vertical section; 3163 - Common vertical section; 317 - Bypass closing channel; 318 - Bypass opening channel; 319 - Sealing groove; 320 - Guide component; 330 - First elastic component; 340 - Fixing seat; 341 - Fixing hole; 350 - Fixing component; 400 - Outer ring empty trigger assembly; 410 - Sleeve; 411 - Sleeve sealing groove; 420 - Connecting fixing component; 430 - Second elastic component; 500 - Upper bypass area; 600 - Lower bypass area. Detailed Implementation

[0031] A wellbore sleeve is a downhole tool used in oil and gas wells and is also an important well completion tool. By opening or closing the flow channel between the tubing and the annulus, the wellbore sleeve can selectively open or close the flow path at specific formations. For example, in multi-layered oil and gas reservoirs, operating the sleeve allows for independent control of different formations, thereby optimizing oil and gas production. Simultaneously, wellbore sleeves can also be used to transport and position other downhole tools, ensuring that these tools can accurately reach their designated locations for operations.

[0032] In existing technologies, ball-drop sleeves are generally used to control and activate tools. When the sleeve needs to be operated, a ball of a specific size is dropped into the well. The ball enters the sleeve through a ball-drop channel within the drill string or tubing and falls onto a ball seat inside the sleeve. Once the ball is in the ball seat, the sleeve's valve is activated, allowing the flow channel to be opened or closed, altering the fluid flow path. This facilitates subsequent downhole operations, such as selectively producing oil and gas in specific formations or isolating certain well sections.

[0033] However, the existing pitching slide has the following problems:

[0034] (1) The use of ball-launched sliding sleeves requires the drill string to have a ball-launching channel, which increases the manufacturing cost of the drill string.

[0035] (2) This type of sliding sleeve can only be activated once, and the sliding sleeve cannot be reused after activation.

[0036] (3) Throwing a ball into the ball throwing channel may result in ball residue inside the wellbore, loss of the central water eye channel, and impact on subsequent operations.

[0037] (4) It has a certain degree of operational complexity. If the wrong ball is thrown or the ball is not positioned correctly, the sliding sleeve may not work properly.

[0038] In view of this, this application provides an infinitely activating sliding sleeve for lowering into the wellbore. The infinitely activating sliding sleeve includes: an outer sleeve vertically disposed within the wellbore; a bypass mandrel fixed within the outer sleeve and located at the upper part of the outer sleeve; and a flow activation assembly movably disposed within the outer sleeve. A connecting hole penetrating the wall thickness of the outer sleeve is formed on the lower side of the outer sleeve. The bypass mandrel and the outer sleeve form an upper bypass region, and a bypass hole penetrating the wall thickness of the bypass mandrel is formed on the side wall of the bypass mandrel. The flow activation assembly and the outer sleeve form a lower bypass region.

[0039] The flow activation assembly can move axially along the outer bushing under the action of fluid pressure difference, and has an initial state and an activated state. In the initial state, the flow activation assembly extends into the upper bypass area and blocks the bypass hole, while the lower bypass area and the connecting hole are not connected. In the activated state, the flow activation assembly extends out of the upper bypass area and opens the bypass hole, while the lower bypass area and the connecting hole are connected.

[0040] By installing a flow activation assembly that can move axially along the outer bushing inside the outer bushing, the flow activation assembly can be triggered to move downward under the action of fluid pressure difference. This opens the bypass hole that was originally blocked by the flow activation assembly, allowing fluid inside the bypass mandrel to flow in the upper bypass zone. At this time, the pressure in the upper bypass zone is equal to the pressure in the internal flow channel of the bypass mandrel. Simultaneously, the lower bypass zone enclosed by the flow activation assembly and the outer bushing is connected to the connecting hole on the outer bushing that communicates with the outside, thus creating a certain pressure difference between the lower and upper bypass zones, keeping the bypass hole in the open state.

[0041] After the fluid pressure difference is lost, the flow activation assembly returns to its initial state, re-enters the upper bypass zone and blocks the bypass hole, and the lower bypass zone is also no longer connected to the connecting hole. This configuration avoids the problems that may arise from using a ball-operated sliding sleeve, such as clogging of the central water channel, complex operation, and high requirements for drilling tools, and enables the infinite recycling of the sliding sleeve.

[0042] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0043] Figure 1 is a partial cross-sectional view of the infinitely activated sliding sleeve in its initial state according to an embodiment of this application. Figure 2 is an overall cross-sectional view of the infinitely activated sliding sleeve in its initial state according to an embodiment of this application. Figure 3 is a partial cross-sectional view of the infinitely activated sliding sleeve in its activated state according to an embodiment of this application.

[0044] Referring to Figures 1-3, this embodiment of the application provides an infinitely activatable sliding sleeve for lowering into a drilling well. The infinitely activatable sliding sleeve includes an outer sleeve 100, a bypass mandrel 200, and a flow activation assembly 300. The outer sleeve 100 is vertically disposed within the drilling well, and the bypass mandrel 200 is fixed within the outer sleeve 100 and located at its upper part. The flow activation assembly 300 is movably disposed within the outer sleeve 100 and can move axially along the outer sleeve 100 under the influence of fluid pressure differential.

[0045] A bypass mandrel 200 and an outer bushing 100 form an upper bypass region 500. A bypass hole 210 is provided on the side wall of the bypass mandrel 200, and the bypass hole 210 penetrates the wall thickness of the bypass mandrel 200. Multiple bypass holes 210 can be provided and symmetrically arranged circumferentially along the bypass mandrel 200. A flow activation assembly 300 and an outer bushing 100 form a lower bypass region 600. A connecting hole 110 is provided on the lower side of the outer bushing 100, penetrating the wall thickness of the outer bushing 100, and the connecting hole 110 communicates with the drilling.

[0046] The flow activation assembly 300 has an initial state and an activated state. In the initial state, the flow activation assembly 300 extends into the upper bypass area 500 and blocks the bypass hole 210, cutting off the fluid passage between the bypass mandrel 200 and the outer bushing 100. At the same time, the lower bypass area 600 and the connecting hole 110 are not connected.

[0047] When liquid (drilling fluid or water) is injected into the sliding sleeve via a surface pump, the flow activation assembly 300 will move axially along the outer sleeve 100 under the action of fluid pressure differential. When the flow activation assembly 300 moves to its activated state, it extends out of the upper bypass zone 500, and the previously blocked bypass hole 210 is opened, connecting the upper bypass zone 500 to the internal fluid channel. Simultaneously, the lower bypass zone 600 connects to the connecting hole 110, and the lower bypass zone 600 connects to the drilling interior. Due to the pressure differential between the upper bypass zone 500 and the lower bypass zone 600, the flow activation assembly 300 will remain in the activated state, meaning the bypass hole 210 remains open.

[0048] When the injection of liquid (drilling fluid or water) into the sliding sleeve through the surface pump stops, the fluid pressure difference disappears, and the flow activation assembly 300 can return to its initial state, waiting for the next round of activation.

[0049] It is understandable that the lower bypass area 600 and the connection hole 110 can be switched by providing a boss for blocking the connection hole 110 at the lower part of the flow activation assembly 300, or by the flow activation assembly 300 cooperating with other parts provided in the connection hole 110 in the outer bushing 100. The specific implementation form is not limited here.

[0050] This configuration eliminates the need to activate the sliding sleeve and open the bypass hole 210 using the original ball-throwing method. It avoids problems such as clogging of the central water channel, complex ball-throwing operation, and high requirements for drilling tools that may result from using the ball-throwing sliding sleeve, and enables the unlimited recycling of the sliding sleeve.

[0051] The flow activation assembly 300 includes a guide spindle 310 and a guide member 320. The guide spindle 310 is movably disposed within the outer bushing 100 and can move axially along the outer bushing 100. The bottom end of the guide spindle 310 has a throttling section 311, the flow area of ​​which is smaller than the flow area of ​​other parts of the guide spindle 310. Furthermore, a limiting track 312 is provided on the outer wall of the guide spindle 310, having an upper limiting end 313 and a lower limiting end 315. The guide member 320 passes through the outer bushing 100 and extends into the limiting track 312. When the guide spindle 310 moves axially, the guide member 320 can slide along the limiting track 312. When the guide member 320 is located at the lower limiting end 315 of the limiting track 312, the flow activation assembly 300 is in its initial state. When the guide component 320 is located at the upper limit end 313 of the limiting track 312, the flow activation assembly 300 is in an activated state. It is understood that the guide component 320 can be a screw, pin, rivet, or other structure, and there is no limitation on it here.

[0052] Because the flow area of ​​the throttling section 311 is smaller than that of other parts of the guide mandrel 310, when the drilling fluid flows out through the flow channel inside the throttling section 311, according to the orifice throttling principle, the liquid kinetic energy at the lower end face of the throttling section 311 increases and the pressure decreases, generating a liquid pressure difference between the two ends of the throttling section 311, generating a downward thrust, and driving the guide mandrel 310 to move downward along the axial direction of the outer bushing 100. Furthermore, by providing a guide member 320 that passes through the outer bushing 100 and can slide on the limiting rail 312, the axial movement of the guide mandrel 310 can be limited both vertically and horizontally.

[0053] It should be noted that the throttling part 311 can be an internal structure located at one end of the cavity of the changing mandrel 310, and can be integrally formed with the changing mandrel 310. Alternatively, it can be a separate part fixedly connected to one end of the changing mandrel 310; no specific limitation is made here.

[0054] For example, the throttling section 311 can be a throttling short section, which can be fixedly connected to the lower end of the changing mandrel 310, such as by threaded connection, snap-fit ​​connection or pin connection, to enhance the connection stability between the throttling short section and the changing mandrel 310.

[0055] Figure 4 is a schematic diagram of the unfolded limiting track provided in an embodiment of this application. Figure 5 is a partially enlarged schematic diagram of the first channel in Figure 4. Figure 6 is a partially enlarged schematic diagram of the second channel in Figure 4.

[0056] Referring to Figures 4 to 6, the limiting track 312 also includes a middle limiting end 314, which is located between the lower limiting end 315 and the upper limiting end 313. When the guide member 320 is located at the middle limiting end 314, the flow activation assembly 300 still blocks the bypass hole 210, and the bypass channel is not connected.

[0057] Since liquid is also injected into the flow channel of the sliding sleeve during other downhole operations, a middle limit end 314 can be set to accommodate the needs of normal operations to avoid accidental activation of the sliding sleeve during normal operations. During normal operations, the guide 320 will slide to the middle limit end 314. At this time, the bypass hole 210 is still in the closed state and does not affect normal operations.

[0058] Specifically, the limiting track 312 is provided with multiple lower limit ends 315, at least two middle limit ends 314 and at least two upper limit ends 313 in sequence along the circumference. The middle limit ends 314 and the upper limit ends 313 are arranged alternately in sequence, and each middle limit end 314 corresponds to a lower limit end 315 and each upper limit end 313 also corresponds to a lower limit end 315.

[0059] The adjacent middle limit end 314 and upper limit end 313, as well as their corresponding lower limit end 315, are connected by a track-changing channel 316. This configuration allows for switching between two different operational requirements by controlling the liquid injection rate. For example, when normal operation is required, the guide 320 is driven into the middle limit end 314; when the bypass hole 210 needs to be opened, the guide 320 is driven into the upper limit end 313.

[0060] In one implementation, the track-changing channel 316 includes a first channel 3161 and a second channel 3162, and the track-changing channels 316 are arranged in an array along the circumferential direction. The two ends of the first channel 3161 are respectively connected to a lower limit end 315 and a corresponding middle limit end 314 or an upper limit end 313. The two ends of the second channel 3162 are respectively connected to another lower limit end 315 and a corresponding upper limit end 313 or a middle limit end 314.

[0061] The first channel 3161 and the second channel 3162 share a common vertical section 3163. The first channel 3161 also includes an upper extending vertical section 31611 and a lower extending vertical section 31613 extending beyond both ends of the common vertical section 3163, and a first upwardly inclined section 31612 connected to the other end of the upper extending vertical section 31611 and a first downwardly inclined section 31614 connected to the other end of the lower extending vertical section 31613. The first upwardly inclined section 31612 is connected to one of the middle limiting end 314 and the upper limiting end 313. The first downwardly inclined section 31614 is connected to the lower limiting end 315.

[0062] The second channel 3162 also has a second upwardly inclined section 31621 connected to one end of the common vertical section 3163 and a second downwardly inclined section 31623 connected to the other end of the common vertical section 3163. Furthermore, the second channel 3162 also includes an upper connecting vertical section 31622 connected to the other end of the second upwardly inclined section 31621, and a lower connecting vertical section 31624 connected to the other end of the second downwardly inclined section 31623. The upper connecting vertical section 31622 is connected to one of the middle limiting end 314 and the upper limiting end 313. The lower connecting vertical section 31624 is connected to the lower limiting end 315.

[0063] This configuration can guide the sliding of the guide member 320, enabling it to slide stably in the limiting track 312 and slide to the designated position.

[0064] Taking the lower limit end 315 of the guide member 320 in the initial position as an example, when the guide member 320 is in the rightmost lower limit end 315, the sliding sleeve is in the initial state, the flow activation assembly 300 extends into the upper bypass area 500 and blocks the bypass hole 210, and the lower bypass area 600 is not connected to the connecting hole 110.

[0065] If a large volume of liquid is injected into the sliding sleeve, under the action of the liquid pressure difference, the guide 320 slides upward along the lower connecting vertical section 31624 of the second channel 3162, and enters the common vertical section 3163 in the second channel 3162 on the left under the guidance of the second lower inclined section 31623. After passing through the common vertical section 3163, it enters the first channel 3161 on the left under the guidance of the upper extending vertical section 31611 of the first channel 3161, and finally reaches the middle limit end 314. At this time, the downward movement distance of the flow activation assembly 300 is limited, and part of the flow activation assembly 300 still extends into the upper bypass area 500 and covers the outside of the bypass mandrel 200. The bypass hole 210 is still blocked, the bypass channel is not opened, and normal downhole operations can be achieved.

[0066] When liquid injection stops, the guide 320 slides downward from the middle limiting end 314 along the upper connecting vertical section 31622 of the second channel 3162, and slides to the common vertical section 3163 in the second channel 3162 to the left under the guidance of the second upper inclined section 31621. After passing through the common vertical section 3163, and guided by the lower extending vertical section 31613 of the first channel 3161, it reaches the lower limiting end 315 of the first channel 3161 to the left. This cycle repeats, allowing the guide 320 to slide along the bypass closing channel 317 without opening the bypass.

[0067] Taking the lower limit end 315 of the guide member 320 in the initial position as an example, when the guide member 320 is in the rightmost lower limit end 315, the sliding sleeve is in the initial state, the flow activation assembly 300 extends into the upper bypass area 500 and blocks the bypass hole 210, and the lower bypass area 600 is not connected to the connecting hole 110.

[0068] If a small volume of liquid is injected into the sliding sleeve, under the action of the liquid pressure difference, the guide 320 slides upward along the lower connecting vertical section 31624 in the second channel 3162, and slides to the common vertical section 3163 in the second channel 3162 to the left under the guidance of the second lower inclined section 31623. When the guide 320 slides to the common vertical section 3163, due to the small pressure difference, the guide 320 will not continue to slide upward.

[0069] Subsequently, by stopping the injection of liquid and eliminating the liquid pressure difference, the guide 320 will enter the first channel 3161 under the guidance of the lower extending vertical section 31613 of the first channel 3161, and finally reach the lower limit end 315 of the first channel 3161 on the left side under the guidance of the first lower inclined section 31614. At this time, a large volume of liquid is injected into the sliding sleeve. Under the action of the liquid pressure difference, the guide 320 will slide upward along the lower connecting vertical section 31624 of the second channel 3162, and enter the common vertical section 3163 on the left side under the guidance of the second lower inclined section 31623. After passing through the common vertical section 3163, it will continue to slide upward, and enter the first channel 3161 on the left side under the guidance of the upper extending vertical section 31611 of the first channel 3161, and finally reach the upper limit end 313 in the first channel 3161 along the first upper inclined section 31612. At this time, the flow activation assembly 300 extends out of the upper bypass area 500, the bypass hole 210 is opened, the bypass channel is connected, and bypass operation can be realized.

[0070] When the liquid injection stops, the guide 320 slides downward from the upper limit end 313 along the upper connecting vertical section 31622 of the second channel 3162, and then slides to the common vertical section 3163 in the second channel 3162 to the left under the guidance of the second upper inclined section 31621. Subsequently, guided by the lower extending vertical section 31613 of the first channel 3161, it reaches the lower limit end 315 of the first channel 3161 to the left. This cycle repeats, enabling the bypass opening operation, with the guide 320 sliding along the bypass opening channel 318.

[0071] As one implementation method, a transition arc segment can be provided at the corner of the limiting track 312 to reduce stress concentration within the limiting track 312 and to reduce friction and wear of the guide member 320 within the limiting track 312. It should be noted that the upper, lower, left, and right relationships in the above description of the limiting track 312 are all based on the paper orientation in Figure 4.

[0072] Figure 7 is a structural schematic diagram of the variable track mandrel provided in an embodiment of this application. Figure 8 is a structural schematic diagram of the flow activation assembly provided in an embodiment of this application. Referring to Figures 7 and 8, the variable track mandrel 310 includes a first shaft segment 3101, a second shaft segment 3102, and a third shaft segment 3103 connected in sequence. The shaft diameters of the first shaft segment 3101, the second shaft segment 3102, and the third shaft segment 3103 decrease sequentially, and a limiting rail 312 is disposed on the first shaft segment 3101. The first shaft segment 3101 is tightly fitted to the inner wall of the outer bushing 100, and to prevent liquid leakage and ensure that the upper and lower spaces of the cavity are sealed, the first shaft segment 3101 is also provided with a plurality of sealing grooves 319 for accommodating sealing elements. Specifically, sealing elements are provided between the outer wall of the first shaft segment 3101 and the inner wall of the outer bushing 100 and / or between the inner wall of the first bushing and the outer wall of the bypass mandrel 200.

[0073] In some embodiments, the flow activation assembly 300 further includes a first elastic element 330, which is sleeved on the second shaft segment 3102. The upper end of the first elastic element 330 abuts against the first shaft segment 3101, and the lower end of the first elastic element 330 abuts against the inner wall of the outer bushing 100. Specifically, the first elastic element 330 may be a spring sleeved on the outer wall of the second shaft segment 3102, with the upper end of the spring abutting against the lower end face of the first shaft segment 3101 and the lower end of the spring abutting against the inner wall of the outer bushing 100. Under the action of gravity, the spring is compressed in its initial state.

[0074] When the change track spindle 310 moves downward along the axial direction of the outer bushing 100, the spring is further compressed due to the restriction of the inner wall of the outer bushing 100. With this configuration, when the throttling pressure difference disappears, the reaction force generated by the first elastic element 330 can apply an upward thrust to the first shaft segment 3101 of the change track spindle 310, causing the flow activation assembly 300 to quickly return to its initial state.

[0075] In one implementation, the third shaft segment 3103 has a flow channel hole 3104 for fluid inlet and outlet, and the flow channel hole 3104 is located close to the second shaft segment 3102. With this configuration, when the flow activation assembly 300 moves axially downwards, the liquid between the second shaft segment 3102, the third shaft segment 3103, and the outer bushing 100 can enter the internal flow channel of the guide mandrel 310 through the flow channel hole 3104 and be discharged promptly. This prevents the annular space from becoming an incompressible dead cavity, thus avoiding obstruction of the movement of the flow activation assembly 300.

[0076] To improve the stability of the connection between the flow activation assembly 300 and the outer bushing 100, the flow activation assembly 300 may further include a fixed seat 340 and a fixing member 350. The fixed seat 340 is sleeved on the outside of the second shaft segment 3102 of the guide rail spindle 310 and abuts against the inner wall of the outer bushing 100. The lower end of the first elastic member 330 is connected to the fixed seat 340. Furthermore, the fixing member 350 passes through the fixed seat 340, thus fixing the fixed seat 340 to the second shaft segment 3102.

[0077] Specifically, the fixing base 340 is provided with multiple fixing holes 341 along the circumference, and multiple fixing members 350 can be connected to the second shaft segment 3102 through the fixing holes 341. For example, the fixing member 350 can be a shear pin, and the fixing base 340 can be a shear pin holder. Multiple shear pins are screwed into the corresponding shear pin holes 3105 provided in the second shaft segment 3102 through the multiple fixing holes 341 provided on the shear pin holder, so that before the sliding sleeve is activated, the relative position between the changing track spindle 310 and the outer bushing 100 can remain unchanged, without affecting normal operation. It should be noted that the shear pin holes 3105 do not penetrate the wall thickness of the changing track spindle 310. When the sliding sleeve is activated, under the action of fluid pressure difference, the shear pins passing through the shear pin holder are sheared, and the changing track spindle 310 can move axially relative to the outer bushing 100.

[0078] Referring again to Figures 1-3, the infinitely activated sliding sleeve also includes an outer ring empty trigger assembly 400, which is connected inside the outer bushing 100 and located at the lower part of the outer bushing 100. Furthermore, the outer ring empty trigger assembly 400 extends into the lower bypass region 600 and can extend and retract along the axial direction of the outer bushing 100. It can be understood that, at this time, the lower bypass region 600 is formed by the flow activation assembly 300, the outer bushing 100, and the outer ring empty trigger assembly 400.

[0079] When the flow activation assembly 300 is in its initial state, the outer ring empty trigger assembly 400 blocks the connecting hole 110, and the lower bypass area 600 is not connected to the outside. When the flow activation assembly 300 is in the activated state, as the flow activation assembly 300 moves downward along the axial direction, it forces the outer ring empty trigger assembly 400 to move downward as well. The connecting hole 110, which was originally blocked by the outer ring empty trigger assembly 400, is opened, and the lower bypass area 600 connects with the connecting hole 110 and is connected to the outside.

[0080] By setting an outer ring empty trigger assembly 400 that cooperates with the flow activation assembly 300, it is not necessary to set a boss at the bottom of the flow activation assembly 300 to block the connecting hole 110. This can reduce the weight of the flow activation assembly 300, reduce the machining requirements of the flow activation assembly 300, reduce the friction and wear between the flow activation assembly 300 and the outer bushing 100, and improve the fatigue life and overall strength of the flow activation assembly 300.

[0081] In one embodiment, the outer ring trigger assembly 400 includes a sleeve 410, a connecting fastener 420, and a second elastic element 430. The connecting fastener 420 is fixedly connected to the lower end of the outer bushing 100. For example, the connecting fastener 420 can be threaded to the inner wall of the lower end of the outer bushing 100, restricting its downward movement. The second elastic element 430 is connected between the connecting fastener 420 and the sleeve 410. Under the weight of the sleeve 410, the second elastic element 430 is initially in a compressed state and provides a reaction force, causing the upper end of the sleeve 410 to abut against the inner wall of the outer bushing 100, sealing the connecting hole 110.

[0082] When a liquid pressure difference is generated at both ends of the throttling section 311, the variable track spindle 310 will move downward along the axial direction of the outer bushing 100. The third shaft section 3103, which originally passed through the central hole inside the sleeve 410, moves downward, and the flow channel hole 3104, which was originally connected to the internal cavity of the outer bushing 100, is blocked by the sleeve 410. Since the shaft diameter of the second shaft section 3102 is larger than that of the third shaft section 3103, during the downward movement, the lower end face of the second shaft section 3102 will abut against the upper end face of the sleeve 410 and push the sleeve 410 downward together, thereby releasing the blockage of the connecting hole 110 by the sleeve 410 and connecting the lower bypass area 600 with the connecting hole 110. At this time, since a pressure difference environment is formed between the upper bypass area 500 and the lower bypass area 600, the bypass channel in the upper bypass area 500 will remain open.

[0083] As the second elastic element 430 is further compressed during the downward movement, when the liquid pressure difference disappears, the sleeve 410 will re-seal the connecting hole 110 under the action of the second elastic element 430, and provide an upward thrust for the changing mandrel 310.

[0084] To improve the sealing between the cavities and prevent liquid leakage, the sleeve 410 is also provided with a plurality of sleeve sealing grooves 411 for accommodating the sealing element. Specifically, the sleeve sealing grooves 411 are provided on the side of the outer wall of the sleeve 410 facing the inner wall of the outer bushing 100 and / or on the side of the inner wall of the sleeve 410 facing the bypass mandrel 200.

[0085] Figure 9 is a schematic diagram of the structure of the outer bushing 100 provided in the embodiment of this application. The outer bushing 100 is vertically disposed in the drilling or drill string and is provided with a central hole through which the flow activation assembly 300, the outer annular trigger assembly 400 and the bypass mandrel 200 pass.

[0086] The upper end of the inner wall of the outer bushing 100 is provided with a first thread 150, which can be fixedly connected to the bypass spindle 200. The lower end of the inner wall of the outer bushing 100 is provided with a second thread 160, which can be threadedly connected to the fixed connector of the outer ring trigger assembly 400.

[0087] The inner wall of the outer bushing 100 is also provided with a first shoulder 120 and a second shoulder 130. The first shoulder 120 is used to abut against the lower end face of the fixed seat 340 provided on the flow activation assembly 300 to restrict its downward movement in the axial direction of the outer bushing 100. The second shoulder 130 is used to abut against the upper end face of the sleeve 410 provided on the outer annular trigger assembly 400 to restrict its upward movement in the axial direction of the outer bushing 100.

[0088] The outer bushing 100 also includes symmetrically arranged track screw holes 140. The track screw holes 140 penetrate the wall thickness of the outer bushing 100 and correspond one-to-one with the guide members 320. For example, the guide member 320 is a track screw, which passes through the track screw hole 140, is inserted into the limiting track 312, and can slide within the limiting track 312. It is understood that, initially, the track screw is located at the lower limiting end 315 in the limiting track 312.

[0089] With the above-described structure, when the downhole tools require bypass operation, the pump can be switched on and off at the surface, and the pump displacement can be controlled to switch the bypass. When the drilling fluid flows through the throttling section 311 from the internal flow channel of the sliding sleeve, the pressure difference generated by the orifice blocking causes the throttling section 311 to generate a downward thrust, which drives the guide spindle 310 to move downward, and causes the guide member 320 to move along the trajectory of the limiting track 312.

[0090] In the initial state, the guide member 320 is located at the lower limit end 315 of the bypass closing channel 317 provided on the rail change mandrel 310. At the same time, the first elastic member 330 is compressed, the ground high-volume pump is activated, and the throttling part 311 generates a downward thrust, driving the rail change mandrel 310 downward and causing the guide member 320 to move upward along the bypass closing channel 317 until it is blocked at the middle limit end 314 on the left. At this time, the bypass hole 210 on the bypass mandrel 200 is not connected to the upper bypass area 500, the bypass is in the closed position, and this state is maintained.

[0091] When the pump stops on the ground, the track-changing spindle 310 is subjected to an upward force from the first elastic element 330, causing the track-changing spindle 310 to move upward and the guide element 320 to slide downward along the bypass closing channel 317, moving from the middle limit end 314 to the lower limit end 315 on the left.

[0092] When the bypass needs to be opened to form the state shown in Figure 1, the ground small displacement pump is started, the throttling part 311 generates a downward thrust to drive the rail change spindle 310 to move downward, and the guide 320 moves upward from the lower limit end 315 along the bypass closing channel 317 to the common vertical section 3163.

[0093] At this time, the ground pump stops, and the rail-changing spindle 310 is subjected to the upward force of the first elastic element 330. The rail-changing spindle 310 moves upward and causes the guide element 320 to slide downward along the bypass opening channel 318, moving from the common vertical section 3163 to the lower limit end 315 on the left.

[0094] Subsequently, the ground-based high-volume pump is activated, and the throttling section 311 generates a downward thrust, driving the guide spindle 310 downward and causing the guide member 320 to move upward along the bypass opening channel 318 until it is blocked at the upper limit end 313 on the left. At this time, the bypass hole 210 on the bypass spindle 200 is connected to the upper bypass area 500, and the bypass is in the open position. The pressure in the upper bypass area 500 is greater than the pressure in the lower bypass area 600, forming a pressure differential environment, which can maintain the open state.

[0095] Each time the bypass is switched, the ground-based small-displacement pump needs to be started and stopped once. The rail-changing spindle 310 moves downward and the guide 320 slides to the common vertical section 3163, switching the bypass closing channel 317 and the bypass opening channel 318, thereby realizing the normal large-displacement pump start-up operation switch bypass switching.

[0096] The working principle of the unlimited activation slide provided in this application embodiment is as follows:

[0097] Upon initial use, a large volume of liquid can be injected into the fluid channel within the sliding sleeve via a surface pump. As the liquid passes through the throttling section 311, the orifice suddenly narrows, generating a downward thrust under the throttling effect. This shears off the fixing member 350 originally connected to the second shaft section 3102, allowing the changing mandrel 310 to move axially downwards. Under normal operation, the guide member 320 slides along the bypass closing channel 317 in the limiting track 312 and reaches the middle limiting end 314. At this time, the bypass hole 210 remains blocked, the bypass channel is not opened, the sliding sleeve is not activated, and normal downhole operations are not affected. Furthermore, after the surface pump stops injecting liquid, the pressure difference generated by the throttling effect disappears, and the changing mandrel 310 returns to its initial state under the action of the spring.

[0098] When activation of the sliding sleeve is required, liquid is first injected into the fluid channel inside the sliding sleeve at a small flow rate using a ground pump, causing the guide 320 to slide to the common vertical section 3163. Then, the liquid injection is stopped, causing the guide 320 to switch to the bypass opening channel 318 and slide to the lower limit end 315 corresponding to the next initial state. At this point, when liquid is injected into the sliding sleeve at a large flow rate again, the guide 320 will slide from the previous lower limit end 315 along the bypass opening channel 318 to the next upper limit end 313, thereby opening the bypass hole 210 and activating the bypass flow channel.

[0099] Understandably, whether switching from bypass opening channel 318 to bypass closing channel 317, or from bypass closing channel 317 to bypass opening channel 318, whenever track switching is required, the guide 320 can be moved to the common vertical section 3163 by first starting the ground pump with a small displacement, and then stopping the injection of liquid to switch the guide 320 to another channel.

[0100] The unlimited activation sliding sleeve provided in this application embodiment requires no ball dropping and eliminates the need for a ball dropping channel in the drill string. Activation of the sliding sleeve is achieved simply by controlling the surface pump displacement according to the downhole tool activation requirements. Furthermore, activating the sliding sleeve's downward movement through two pump starts and stops at different displacements prevents accidental activation and avoids interfering with other operational requirements for normal displacement. This unlimited activation sliding sleeve allows for unlimited opening and closing of the bypass in the downhole, providing greater flexibility and enabling adjustments to the downhole operation plan as needed, further improving operational efficiency.

[0101] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An unlimited activation sliding sleeve for running into a wellbore, the sliding sleeve comprising: The infinitely activated sliding sleeve includes: An outer bushing is vertically disposed inside the well; a connecting hole is provided on the lower side of the outer bushing, and the connecting hole penetrates the wall thickness of the outer bushing; A bypass mandrel is fixed inside the outer bushing and located at the upper part of the outer bushing. The bypass mandrel and the outer bushing form an upper bypass area. A bypass hole is provided on the side wall of the bypass mandrel, and the bypass hole penetrates the wall thickness of the bypass mandrel. A flow activation assembly is movably disposed within the outer bushing, and the flow activation assembly and the outer bushing form a lower bypass area; The flow activation assembly can move axially along the outer bushing under the action of fluid pressure difference, and has an initial state and an activated state. In the initial state, the flow activation assembly extends into the upper bypass area and blocks the bypass hole, while the lower bypass area is not connected to the connecting hole. In the activated state, the flow activation assembly extends out of the upper bypass area and opens the bypass hole, while the lower bypass area is connected to the connecting hole.

2. The infinite activation sliding sleeve of claim 1, wherein, The traffic activation assembly includes: A track-changing mandrel is movably disposed within the outer bushing; the bottom end of the track-changing mandrel has a throttling section, the flow area of ​​which is smaller than the flow area of ​​other parts of the track-changing mandrel; and a limit track is provided on the outer wall of the track-changing mandrel. A guide member is inserted through the outer bushing, the guide member extends into the limiting track, and slides along the limiting track; When the guide is located at the lower limit end of the limiting track, the flow activation assembly is in the initial state; when the guide is located at the upper limit end of the limiting track, the flow activation assembly is in the activated state.

3. The infinite activation sliding sleeve of claim 2, wherein, The limiting track also includes a middle limiting end, which is located between the lower limiting end and the upper limiting end; When the guide is located at the middle limit end, the flow activation assembly still blocks the bypass hole.

4. The infinite activation sliding sleeve of claim 3, wherein, The limiting track is provided with a plurality of lower limiting ends, at least two middle limiting ends and at least two upper limiting ends in sequence along the circumference. The middle limiting ends and the upper limiting ends are arranged alternately in sequence, and each middle limiting end corresponds to one lower limiting end and each upper limiting end also corresponds to one lower limiting end. The adjacent middle limit end and the upper limit end, as well as the lower limit end corresponding to both, are connected by a track-changing channel.

5. The infinite activation sliding sleeve of claim 4, wherein, The track-changing channel includes a first channel and a second channel. The two ends of the first channel are respectively connected to a lower limit end and a corresponding middle limit end or an upper limit end. The two ends of the second channel are respectively connected to another lower limit end and a corresponding upper limit end or a middle limit end. The first channel and the second channel have a common vertical section, and the first channel further includes an upwardly extending vertical section and a first upwardly inclined section extending upward from the upper end of the common vertical section, and a downwardly extending vertical section and a first downwardly inclined section extending downward from the lower end of the common vertical section. The second channel further includes a second upwardly inclined section and an upper connecting vertical section extending upward from the upper end of the common vertical section, and a second downwardly inclined section and a lower connecting vertical section extending downward from the lower end of the common vertical section.

6. The unlimited activation sliding sleeve according to any one of claims 2-5, wherein, The track-changing spindle includes a first shaft segment, a second shaft segment, and a third shaft segment connected in sequence, with the shaft diameters of the first shaft segment, the second shaft segment, and the third shaft segment decreasing sequentially, and the limiting rail being disposed on the first shaft segment; The flow activation assembly further includes a first elastic element, which is sleeved on the second shaft segment; the upper end of the first elastic element abuts against the first shaft segment, and the lower end of the first elastic element abuts against the inner wall of the outer shaft sleeve.

7. The infinitely activating sliding sleeve according to claim 6, characterized in that, The third shaft section has a flow channel hole for fluid to enter and exit, and the flow channel hole is close to the second shaft section.

8. The infinitely activating sliding sleeve according to claim 6, characterized in that, The flow activation assembly also includes a mounting base and a fastener; The lower end of the first elastic element is connected to the fixed seat, and the fixed seat abuts against the inner wall of the outer bushing; and the fixed seat is connected to the variable track spindle through the fixing element.

9. The infinitely activating sliding sleeve according to any one of claims 1-8, characterized in that, The infinitely activating sliding sleeve also includes: An outer ring open-circuit trigger assembly is connected inside the outer bushing and located at the lower part of the outer bushing; the outer ring open-circuit trigger assembly is axially extendable along the outer bushing; and the outer ring open-circuit trigger assembly extends into the lower bypass area; In the initial state, the outer ring empty trigger assembly blocks the connecting hole; in the active state, the outer ring empty trigger assembly opens the connecting hole, and the lower bypass area connects with the connecting hole.

10. The infinitely activating sliding sleeve according to claim 9, characterized in that, The outer ring air trigger assembly includes a sleeve, a connecting fastener, and a second elastic element; The connecting fastener is fixed to the lower end of the outer bushing, the second elastic element is connected between the connecting fastener and the sleeve, and the upper end of the sleeve abuts against the inner wall of the outer bushing.

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