A switchable hydraulic sliding sleeve

Abstract

The present invention discloses a switchable hydraulic sleeve, characterized in that it comprises: a base pipe, a liquid injection port is provided on the side wall of the base pipe; a sleeve assembly comprises a first sleeve and a second sleeve arranged in sequence along the axis of the base pipe, the first sleeve is slidably built into the base pipe, and has at least a first position for closing the liquid injection port, and a second position for opening the liquid injection port, the second sleeve has a third position away from the liquid injection port, and has a fourth position close to and closing the liquid injection port, and the second sleeve also has a connection portion connected to a driving device; the liquid injection port can be opened by driving the first sleeve to slide from the first position to the second position. When the liquid injection port needs to be closed temporarily, the driving device can be used to drive the second sleeve from the third position to the fourth position, thereby temporarily closing the liquid injection port. When the process is completed, the driving device is used to drive the second sleeve back to the third position, thereby opening the liquid injection port.

Description

Technical Field

[0001] The invention relates to the field of downhole equipment, and in particular to a switchable hydraulic sliding sleeve. Background Art

[0002] In recent years, the shale gas revolution has not only improved the United States' energy self-sufficiency level, but also promoted the global energy supply and demand pattern. The biggest technological innovation in this process is the hydraulic fracturing technology used to extract shale gas, which is the technology of injecting filling fluid into the formation to fracture the rock wall, thereby allowing oil and gas to flow.

[0003] The hydraulic sleeve is mostly used to open and close the injection port for injecting filling fluid into the formation. Its structure can be found in the patent application number CN201610970676.2. The sleeve receives the ball through the internal ball seat. After receiving the ball, the ball seat is subjected to hydraulic pressure, and then pushes the piston in the sleeve under the action of hydraulic pressure, thereby opening the injection port. However, after the ball seat drives the piston to open the injection port, the ball seat cannot be controlled again, and accordingly, the piston cannot be controlled again, resulting in the injection port being unable to be closed once it is opened. However, in some work scenarios, the injection port needs to be temporarily closed. However, the sleeve in the prior art does not have a means to quickly close the injection port.

[0004] Therefore, how to temporarily and conveniently open and close the liquid injection port is a technical problem that needs to be solved urgently. Summary of the invention

[0005] The purpose of the present invention is to overcome the above technical deficiencies and to provide a switchable hydraulic sleeve to solve the technical problem in the prior art that the liquid injection port cannot be conveniently opened and closed.

[0006] In order to achieve the above technical objectives, the technical solution of the present invention provides a switchable hydraulic sleeve, characterized in that it includes:

[0007] A base tube, a liquid injection port is provided on a side wall thereof;

[0008] A sleeve assembly comprises a first sleeve and a second sleeve arranged in sequence along the axis of the base pipe, the first sleeve is slidably built into the base pipe, and has at least a first position closing the liquid injection port, and a second position opening the liquid injection port, and the first sleeve only slides unidirectionally from the first position to the second position, the second sleeve has a third position away from the liquid injection port, and a fourth position close to and closing the liquid injection port, and the second sleeve can slide back and forth between the third position and the fourth position, and the second sleeve also has a connecting portion for connecting a driving device.

[0009] Furthermore, a first matching portion and a second matching portion are arranged on the base tube along the axial direction, and the second sleeve also has a positioning portion. When the second sleeve is in the third position, the positioning portion contacts the first matching portion to limit the second sleeve from sliding relative to the base tube. When the second sleeve is in the fourth position, the positioning portion contacts the second matching portion to limit the second sleeve from sliding relative to the base tube.

[0010] Furthermore, a positioning groove is provided on the outer wall of the second sleeve, and the positioning portion is a positioning C-shaped ring, which is embedded in the positioning groove and has an elastic force to press against the inner wall of the base tube, and the first matching portion and the second matching portion are the first matching groove and the second matching groove provided on the inner wall of the base tube.

[0011] Furthermore, one end of the first matching groove close to the second matching groove has a tapered surface with a gradually decreasing diameter, and one end of the second matching groove close to the first matching groove has a tapered surface with a gradually decreasing diameter.

[0012] Furthermore, the connecting portion has two oppositely arranged driving grooves, and the two ends of the driving groove respectively have a pressure wall and a guide wall, the inner angle between the pressure wall and the groove bottom is not greater than 90 degrees, and the inner angle between the guide wall and the groove bottom is not less than 90 degrees.

[0013] Furthermore, it also includes a ball seat, which can withstand hydraulic pressure to slide relative to the base pipe, and is connected to the first sleeve to drive the first sleeve to slide from the first position to the second position. The ball seat includes a mounting tube, a limiter and a receiving tube closed at one end. A guide hole is opened on the side wall of the mounting tube, and a matching hole is opened at the end of the receiving tube away from its opening. The inner wall of the receiving tube has a ball holder, and the receiving tube is slidably built into the mounting tube. The receiving tube has at least a starting position connecting the matching hole and the guide hole, and an end position that closes the matching hole and the guide hole. The limiter is connected to the receiving tube to limit the receiving tube from sliding from the end position to the starting position, wherein the ball holder is used to receive a pitched ball, so that the receiving tube slides from the starting position to the end position under the push of hydraulic pressure.

[0014] Furthermore, a ball seat stop groove is provided on the inner wall of the mounting tube, and the limiting member includes an elastic member, which is installed on the receiving tube, and the elastic member has an elastic pressing end, which presses against the inner wall of the mounting tube, and when the receiving tube is in the terminal position, the elastic pressing end is embedded in the ball seat stop groove.

[0015] Furthermore, a ball seat installation groove is opened on the outer wall of the receiving tube, and the elastic member is a ball seat C-shaped ring, which is embedded in the ball seat installation groove, and the ball seat C-shaped ring has elastic force to press against the inner wall of the installation tube.

[0016] Furthermore, a limiting groove is provided on the inner wall of the installation tube, and a sliding key is provided on the outer wall of the receiving tube, and the sliding key is slidably embedded in the limiting groove.

[0017] Furthermore, the limiting groove is annular, and a plurality of latching teeth are formed on its inner wall along the circumferential direction, and a plurality of matching teeth are formed on the outer wall of the sliding key along the circumferential direction, and the matching teeth are slidably embedded in the latching tooth gaps in a one-to-one correspondence.

[0018] Compared with the prior art, the beneficial effects of the present invention include: first, the first sleeve is placed in the first position and the second sleeve is placed in the third position. When the liquid injection port needs to be opened, the first sleeve is driven to slide from the first position to the second position, thereby opening the liquid injection port. When certain processes require the liquid injection port to be temporarily closed, the driving device can be used to connect the connecting part and drive the second sleeve to slide from the third position to the fourth position, thereby temporarily closing the liquid injection port. When the process is completed, the driving device can be used to drive the second sleeve to return the second sleeve from the fourth position to the third position, thereby opening the liquid injection port. By using the switchable hydraulic sleeve provided by the present invention, the liquid injection port can be temporarily closed by the second sleeve after the liquid injection port is opened. The problem that the liquid injection port cannot be temporarily closed after opening is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 2 is a schematic diagram of the structure of a switchable hydraulic sleeve according to an embodiment of the present invention;

[0020] Figure 2 is a schematic diagram of the structure of the switchable hydraulic sleeve in another state according to an embodiment of the present invention;

[0021] Figure 3 is a partial schematic diagram of a second sleeve according to an embodiment of the present invention;

[0022] Figure 4 is a schematic diagram of the ball seat structure of an embodiment of the present invention;

[0023] Figure 5 is a schematic structural diagram of a ball seat in another state according to an embodiment of the present invention;

[0024] Figure 6 It is a schematic structural diagram of the latching teeth and the matching teeth according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0026] The embodiment of the present invention provides a switchable hydraulic sleeve, which can be seen in Figure 1 and Figure 2 , which comprises: a base pipe 100 , a sleeve assembly 200 and a ball seat 300 , and a liquid injection port 110 is opened on the side wall of the base pipe 100 .

[0027] The sleeve assembly 200 includes a first sleeve 210 and a second sleeve 220 arranged in sequence along the axis of the base pipe 100. The first sleeve 210 is slidably built into the base pipe 100 and has at least a first position closing the injection port 110 and a second position opening the injection port 110. The second sleeve 220 has a third position away from the injection port 110 and a fourth position close to and closing the injection port 110. The second sleeve 220 also has a connection portion 221 for connecting a driving device. The ball seat 300 can withstand hydraulic pressure to slide relative to the base pipe 100, and is connected to the first sleeve 210 to drive the first sleeve 210 to slide from the first position to the second position.

[0028] It should be noted that the ball seat 300 can receive the ball and cooperate with the ball to seal the two ends of the base pipe 100, so that the ball seat 300 can slide relative to the base pipe 100 under the push of hydraulic pressure. Since the first sleeve 210 needs to be pushed by the ball seat 300, after the first sleeve 210 reaches the second position from the first position under the drive of the ball seat 300, it is difficult to use the first sleeve 210 to retreat from the second position to the first position, and it is also impossible to use the first sleeve 210 to temporarily close the injection port 110. Accordingly, the second sleeve 220 is needed to temporarily close the injection port 110.

[0029] In the actual operation process, firstly, the first sleeve 210 is placed in the first position and the second sleeve 220 is placed in the third position. When the injection port 110 needs to be opened, the ball seat 300 is used to drive the first sleeve 210 to slide from the first position to the second position, thereby opening the injection port 110. When the injection port 110 needs to be temporarily closed during certain processes, the driving device can be used to connect the connecting portion 221 and drive the second sleeve 220 to slide from the third position to the fourth position, thereby temporarily closing the injection port 110. When the process is completed, the driving device can be used to drive the second sleeve 220 so that the second sleeve 220 returns from the fourth position to the third position, thereby opening the injection port 110. By using the switchable hydraulic sleeve provided by the present invention, the injection port 110 can be temporarily closed by the second sleeve 220 after the injection port 110 is opened.

[0030] Although the second sleeve 220 is only used to temporarily close the injection port 110, it is still necessary for the second sleeve 220 to be able to stay relatively stably in the third position or the fourth position. In a preferred embodiment, the first matching portion 120 and the second matching portion 130 are arranged on the base tube 100 along the axial direction, and the second sleeve 220 also has a positioning portion 222. When the second sleeve 220 is in the third position, the positioning portion 222 contacts the first matching portion 120 to limit the second sleeve 220 from sliding relative to the base tube 100. When the second sleeve 220 is in the fourth position, the positioning portion 222 contacts the second matching portion 130 to limit the second sleeve 220 from sliding relative to the base tube 100. It can be understood that the distance between the first matching portion 120 and the second matching portion 130 is the distance between the third position and the fourth position. At the same time, there are many ways of matching between the positioning portion 222, the first matching portion 120 and the second matching portion 130, as long as the second sleeve 220 can be limited from sliding relative to the base tube 100. For example, the first matching portion 120 and the second matching portion 130 may be two brake pads, and the positioning portion 222 may be a protrusion slightly protruding from the side wall of the second sleeve 220. When the protrusion contacts the brake pads, it can prevent the second sleeve 220 from sliding relative to the base tube 100.

[0031] In a preferred embodiment, a positioning groove 223 is provided on the outer wall of the second sleeve 220, and the positioning portion 222 is a positioning C-shaped ring, which is embedded in the positioning groove 223, and the positioning C-shaped ring has elastic force to press against the inner wall of the base tube 100, and the first matching portion 120 and the second matching portion 130 are the first matching groove and the second matching groove provided on the inner wall of the base tube 100. When the second sleeve 220 is between the third position and the fourth position, the positioning C-shaped ring is compressed and completely embedded in the positioning groove 223, and when the second sleeve 220 is in the third position or the fourth position, part of the positioning C-shaped ring is embedded in the first matching groove or the second matching groove.

[0032] In order to prevent the second sleeve 220 from being completely stuck in the third position or the fourth position, based on the above embodiment, one end of the first matching groove close to the second matching groove has a tapered surface with a gradually decreasing diameter, and one end of the second matching groove has a tapered surface with a gradually decreasing diameter. In this way, when the second sleeve needs to be disengaged from the third position or the fourth position, the positioning C-ring can be gradually compressed under the guidance of the tapered surface, and then completely embedded in the positioning groove 223, so that the positioning C-ring can be disengaged from the first matching groove or the second matching groove.

[0033] The connecting portion 221 is used to connect to the output end of the driving device. The connection form between the connecting portion 221 and the driving device can refer to the relevant structure of the existing downhole equipment. Since the second casing is located in a deep well, the driving device often uses a winch device. In a preferred embodiment, the connecting portion 221 is two driving grooves arranged opposite to each other, and the output end of the driving device is a hook A. When the injection port 110 is temporarily closed, the hook A clamps one of the driving grooves. When the injection port 110 is reopened, the hook A clamps the other driving groove.

[0034] See also Figure 3 , the driving groove has a pressing wall 221a at one end and a guiding wall 221b at the other end, wherein the included angle between the guiding wall 221b and the groove bottom 221c is an obtuse angle, thereby guiding the hook A, and the included angle between the pressing wall 221a and the groove bottom 221c is an acute angle (or a right angle), thereby making the hook A stuck with the pressing wall 221a, so that the driving device can drive the second sleeve 220. In actual operation, the driving device can lower the hook A to one end of the driving groove guiding wall 221b, and the hook A is embedded in the driving groove under the action of the guiding wall 221b, and then drive the hook A to slide toward the pressing wall 221a, so that the hook A is stuck with the pressing wall 221a, thereby driving the second sleeve 220 to slide.

[0035] In a preferred embodiment, see Figure 4 The ball seat 300 includes: a mounting tube 310, a stopper 320 and a receiving tube 330 with one end closed. A flow guide hole 311 is provided on the side wall of the mounting tube 310, a matching hole 331 is provided on the end of the receiving tube 330 away from the opening thereof, a ball support 332 is provided on the inner wall of the receiving tube 330, and the receiving tube 330 is slidably built into the mounting tube 310. The receiving tube 330 has at least one starting position connecting the matching hole 331 and the flow guide hole 311, so that the two ends of the receiving tube 330 are connected to avoid hydraulic pressure difference at both ends of the receiving tube 330. And a terminal position that closes the matching hole 331 and the flow guide hole 311, so that the two ends of the receiving tube 330 are closed, so that there is a pressure difference at both ends of the receiving tube 330. The stopper 320 is connected to the receiving tube 330 to limit the receiving tube 330 from sliding from the terminal position to the starting position. Among them, the ball holder 332 is used to receive the ball. When the operator releases the ball, the ball holder 332 receives the ball and closes the receiving cylinder 330, so that a hydraulic pressure difference is formed at both ends of the receiving cylinder 330, so that the receiving cylinder 330 slides from the starting position to the end position under the push of the hydraulic pressure.

[0036] First, the installation cylinder 310 is installed inside the base pipe 100, and the installation cylinder 310 is connected to the component to be driven, and the receiving cylinder 330 is in the starting position. Since the flow guide hole 311 and the matching hole 331 are connected, and then the two ends of the receiving cylinder 330 are connected, the pressure difference at the two ends of the receiving cylinder 330 is balanced, and the receiving cylinder 330 is prevented from sliding under the pressure difference at the two ends. When the ball seat 300 needs to be driven, the ball can be released, and the ball holder 332 receives the ball, thereby blocking the two ends of the receiving cylinder 330, so that the receiving cylinder 330 is subjected to hydraulic pressure to slide relative to the installation cylinder 310, so that the receiving cylinder 330 reaches the end position from the starting position. The flow guide hole 311 and the matching hole 331 are closed, so that after the ball is melted, there is still a pressure difference at both ends of the receiving cylinder 330. Under the further promotion of the hydraulic pressure, the receiving cylinder 330 drives the installation cylinder 310 to slide relative to the base pipe 100, thereby driving the component to be driven connected to the installation cylinder 310. At the same time, the limiter 320 limits the receiving tube 330 from sliding from the end position to the starting position, thereby preventing the receiving tube 330 from retreating under the pressure fluctuation of the oil well, thereby preventing the receiving tube 330 from retreating to the starting position again. This avoids the phenomenon of the guide hole 311 and the matching hole 331 being reconnected, and avoids the problem that the ball seat cannot stably maintain the working state due to the pressure fluctuation of the oil well.

[0037] It should be noted that the ball seat provided by the present invention can use a conventional insoluble metal ball or a soluble ball, as long as the ball and the ball holder 332 cooperate with the ball so that the receiving tube 330 can reach the terminal position from the initial position.

[0038] Any form of the limiting member 320 that can limit the receiving tube 330 from sliding from the end position to the initial position is feasible. In a preferred embodiment, a ball seat stop groove 312 is provided on the inner wall of the mounting tube 310. The limiting member 320 includes an elastic member, which is installed on the receiving tube 330, and the elastic member has an elastic pressing end, which presses against the inner wall of the mounting tube 310. When the receiving tube 330 is in the starting position, the elastic member is in a compressed state and does not limit the receiving tube 330 from sliding relative to the mounting tube 310. When the receiving tube 330 is in the end position, the elastic pressing end of the elastic member is embedded in the ball seat stop groove 312 under the action of elastic force. Thereby limiting the receiving tube 330 from sliding relative to the mounting tube. It is easy to think that if the ball seat stop groove 312 is provided on the receiving tube 330 and the elastic member is installed on the mounting tube 310, the same effect can be achieved. It is worth noting that the elastic member has multiple alternatives, for example, the elastic member can be a spring, and its implementation can imitate the lock structure of an umbrella. The elastic member can also be a lock tongue structure, which can refer to the door structure.

[0039] In addition, see Figure 5, a preferred embodiment of the elastic member is also provided, the outer wall of the receiving tube 330 is provided with a ball seat installation groove 333, the elastic member is a ball seat C-shaped ring, the ball seat C-shaped ring is embedded in the ball seat installation groove 333, and the ball seat C-shaped ring has elastic force to press against the inner wall of the installation tube 310. When the receiving tube 330 is in the starting position, the C-shaped ring is completely embedded in the ball seat installation groove 333 under the pressure of the inner wall of the installation tube 310, so that the receiving tube 330 can slide relative to the installation tube 310, and when the receiving tube 330 reaches the end position, the C-shaped ring is partially embedded in the ball seat stop groove 312, thereby preventing the receiving tube 330 from sliding relative to the installation tube 310.

[0040] In a preferred embodiment, in order to limit the bearing tube 330 from sliding between the starting position and the end position, the inner wall of the installation tube 310 is provided with a limiting groove 313, and the outer wall of the bearing tube 330 is provided with a sliding key 334, which is slidably embedded in the limiting groove 313. The length of the limiting groove 313 is equal to the length between the starting position and the end position, and when the bearing tube 330 is in the starting position, the sliding key 334 is located at one end of the limiting groove 313, and when the bearing tube 330 is in the end position, the sliding key 334 is located at the other end of the limiting groove 313. In this way, the moving range of the sliding key 334 is limited by the limiting groove 313, thereby limiting the moving range of the bearing tube 330. It is easy to think that the limiting groove 313 is provided on the bearing tube 330, and the sliding key 334 is extended from the installation tube 310, which can also achieve the same effect.

[0041] Since the guide hole 311 and the matching hole 331 need to be aligned and connected to each other at the starting position, it is necessary to limit the rotation of the receiving cylinder 330 relative to the mounting cylinder 310. Since the receiving cylinder 330 and the mounting cylinder 310 need to bear a large load, in order to make the sliding key 334 have a stronger load capacity, in a preferred embodiment, see Figure 6 The limiting groove 313 is annular, and the sliding key 334 is also annular. At the same time, the inner wall of the limiting groove 313 is formed with a plurality of latch teeth 3131 along the circumferential direction, and the outer wall of the sliding key 334 is formed with a plurality of matching teeth 3341 along the circumferential direction, and the matching teeth 3341 are slidably embedded in the gaps of the latch teeth 3131 in a one-to-one correspondence.

[0042] In a preferred embodiment, in order to enhance the flow-conducting capacity of the guide holes 311 and the matching holes 331, there are multiple guide holes 311, and the multiple guide holes 311 are distributed along the circumference of the mounting tube 310; there are multiple matching holes 331, and the multiple matching holes 331 are distributed along the circumference of the receiving tube 330, and the multiple matching holes 331 correspond one-to-one to the multiple guide holes 311.

[0043] In a preferred embodiment, the receiving tube 330 further has two flow guiding seal rings 335, which are sleeved on the outer wall of the receiving tube body, and the matching hole 331 is located between the two flow guiding seal rings 335. Under the sealing effect of the two flow guiding seal rings 335, on the one hand, when the receiving tube 330 is in the starting position, the liquid flow can be prevented from entering the gap between the receiving tube 330 and the installation tube 310, and on the other hand, when the receiving tube 330 is in the ending position, the flow guiding hole 311 and the matching hole 331 can be completely closed.

[0044] Based on the above embodiment, another preferred embodiment can be derived, in which a flow diversion area is formed between the two flow diversion sealing rings 335, and when the receiving tube 330 is in the starting position, the flow diversion hole 311 is in the flow diversion area, and when the receiving tube 330 is in the ending position, the flow diversion hole 311 is separated from the flow diversion area. In this way, it is not necessary to align the flow diversion hole 311 with the matching hole 331, as long as the flow diversion hole 311 can guide the liquid flow in the flow diversion area when the receiving tube 330 is in the starting position, and the flow diversion hole 311 cannot guide the liquid flow in the flow diversion area when the receiving tube 330 is in the ending position.

[0045] In order to facilitate receiving the pitched ball, in a preferred embodiment, the inner wall of the open end of the receiving tube 330 is formed with a first conical surface with a gradually increasing diameter, so that the lowered pitched ball is guided into the receiving tube 330 by the guiding effect of the first conical surface.

[0046] On the basis of the above embodiment, in order to enlarge the conical opening for the pitching guide, the inner wall of the opening end of the mounting tube 310 is formed with a second conical surface with a gradually increasing diameter. When the receiving tube 330 is in the starting position, the second conical surface contacts the first conical surface.

[0047] In a preferred embodiment, the outer wall of the installation cylinder 310 is formed with a connecting thread, so as to facilitate the use of a screw to connect the component to be driven. It is easy to imagine that the installation cylinder 310 can also be connected to the component to be driven in other ways.

[0048] First, the installation cylinder 310 is installed inside the base pipe 100, and the components to be driven are connected by threads, and the receiving cylinder 330 is placed in the starting position. Since the flow guide hole 311 and the matching hole 331 are connected, the two ends of the receiving cylinder 330 are connected, and the pressure difference at the two ends of the receiving cylinder 330 is balanced, and the receiving cylinder 330 is prevented from sliding under the pressure difference at the two ends. When the ball seat 300 needs to be driven, the ball can be released, and under the guidance of the first cone surface and the second cone surface, the ball enters the receiving cylinder 330, and the ball holder 332 receives the ball, thereby blocking the two ends of the receiving cylinder 330, so that the receiving cylinder 330 is subjected to hydraulic pressure and slides relative to the installation cylinder 310, so that the receiving cylinder 330 reaches the end position from the starting position. The flow guide hole 311 and the matching hole 331 are closed, so that after the ball is loosened (or melted), there will still be a pressure difference at both ends of the receiving cylinder 330. Under the further promotion of hydraulic pressure, the receiving tube 330 drives the installation tube 310 to slide relative to the base pipe 100, thereby driving the components to be driven connected to the installation tube 310. At the same time, when the receiving tube 330 reaches the terminal position, the originally compressed C-shaped ring is embedded in the ball seat stop groove 312 at the left and right lower parts of the elastic force, limiting the receiving tube 330 from sliding relative to the installation tube 310, thereby preventing the receiving tube 330 from retreating under the pressure fluctuation of the oil well, thereby preventing the receiving tube 330 from retreating to the starting position again. In this way, the phenomenon of the guide hole 311 and the matching hole 331 being reconnected is avoided, so that the two ends of the ball seat can be stably separated, avoiding the problem that the ball seat cannot stably maintain the working state due to the pressure fluctuation of the oil well.

[0049] See again Figure 1 and Figure 2 In the process of lowering the hydraulic sleeve in the oil well, the first casing 210 and the receiving tube 330 are prone to slide under the action of inertia. In order to prevent the first casing 210 and the receiving tube 330 from sliding unexpectedly, a shearing assembly is further provided. The shearing assembly includes a first shearing piece 410 and a second shearing piece 420. One end of the first shearing piece 410 is connected to the base pipe 100 and the other end is connected to the first casing 210, while one end of the second shearing piece 420 is connected to the installation tube 310 and the other end is connected to the receiving tube 330. In the process of lowering the hydraulic sleeve, the first shearing piece 410 and the second shearing piece 420 can respectively prevent the first casing 210 and the receiving tube 330 from sliding unexpectedly. When the first casing 210 and the receiving tube 330 need to be driven, the first shearing piece 410 and the second shearing piece 420 can be cut off by hydraulic pressure respectively. It should be noted that the shearing resistance of the second shearing piece 420 needs to be weaker than that of the first shearing piece 410, so that the receiving tube 330 slides before the first casing 210.

[0050] In the actual operation process, the first sleeve 210 is first placed in the first position and the second sleeve 220 is placed in the third position. At this time, the first shearing piece 410 connects the base pipe 100 and the first sleeve 210, and the positioning portion 222 of the second sleeve 220 cooperates with the first matching portion 120, so that the first sleeve 210 and the second sleeve 220 are fixed relative to the base pipe 100. When the base pipe 100 is lowered to the predetermined depth of the oil well, when the injection port 110 needs to be opened, the second shearing piece 420 and the first shearing piece 410 are cut off in sequence under the action of hydraulic pressure, so that the first sleeve 210 is driven by the ball seat 300 to slide from the first position to the second position, thereby opening the injection port 110. When the injection port 110 needs to be temporarily closed during certain processes, the driving device can be used to connect the connecting portion 221 and drive the second sleeve 220 to slide from the third position to the fourth position, thereby temporarily closing the injection port 110. At this time, the positioning portion 222 is separated from the first matching portion 120 and matched with the second matching portion 130, thereby fixing the second sleeve relative to the base pipe 100. When the process is completed, the second sleeve 220 can be driven by the driving device to return the second sleeve 220 from the fourth position to the third position, thereby opening the injection port 110. By using the switchable hydraulic sleeve provided by the present invention, the injection port 110 can be temporarily closed by the second sleeve 220 after the injection port 110 is opened.

[0051] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A switchable hydraulic sleeve, characterized in that: include: A base tube, a liquid injection port is provided on a side wall thereof; A sleeve assembly, comprising a first sleeve and a second sleeve arranged in sequence along the axis of the base pipe, the first sleeve being slidably built into the base pipe and having at least a first position closing the injection port and a second position opening the injection port, and the first sleeve only slides unidirectionally from the first position to the second position, the second sleeve having a third position away from the injection port and a fourth position close to and closing the injection port, and the second sleeve can reciprocate between the third position and the fourth position, and the second sleeve also has a connecting portion for connecting a driving device; A ball seat, which can withstand hydraulic pressure to slide relative to the base pipe, and is connected to the first sleeve to drive the first sleeve to slide from the first position to the second position, the ball seat comprises a mounting tube, a limiter and a receiving tube closed at one end, a flow guide hole is provided on the side wall of the mounting tube, a matching hole is provided at the end of the receiving tube away from the opening thereof, a ball holder is provided on the inner wall of the receiving tube, and the receiving tube is slidably built into the mounting tube, the receiving tube has at least a starting position connecting the matching hole and the flow guide hole, and a terminal position closing the matching hole and the flow guide hole, the limiter is connected to the receiving tube to limit the receiving tube from sliding from the terminal position to the starting position, wherein the ball holder is used to receive a pitched ball, so that the receiving tube slides from the starting position to the terminal position under the push of hydraulic pressure; The connecting portion has two oppositely arranged driving grooves, and the two ends of the driving groove respectively have a pressure wall and a guide wall. The inner angle between the pressure wall and the groove bottom is not greater than 90 degrees, and the inner angle between the guide wall and the groove bottom is not less than 90 degrees.

2. The switchable hydraulic sleeve according to claim 1, characterized in that: A first matching portion and a second matching portion are arranged on the base tube along the axial direction. The second sleeve also has a positioning portion. When the second sleeve is in the third position, the positioning portion contacts the first matching portion to limit the second sleeve from sliding relative to the base tube. When the second sleeve is in the fourth position, the positioning portion contacts the second matching portion to limit the second sleeve from sliding relative to the base tube.

3. The switchable hydraulic sleeve according to claim 2, characterized in that: A positioning groove is provided on the outer wall of the second sleeve, and the positioning portion is a positioning C-shaped ring, which is embedded in the positioning groove and has elastic force to press against the inner wall of the base tube, and the first matching portion and the second matching portion are the first matching groove and the second matching groove provided on the inner wall of the base tube.

4. The switchable hydraulic sleeve according to claim 3, characterized in that: One end of the first matching groove close to the second matching groove has a tapered surface with a gradually decreasing diameter, and one end of the second matching groove close to the first matching groove has a tapered surface with a gradually decreasing diameter.

5. The switchable hydraulic sleeve according to claim 1, characterized in that: A ball seat stop groove is provided on the inner wall of the mounting tube, and the limiting member includes an elastic member, which is mounted on the receiving tube, and the elastic member has an elastic pressing end, which presses against the inner wall of the mounting tube, and when the receiving tube is in the terminal position, the elastic pressing end is embedded in the ball seat stop groove.

6. The switchable hydraulic sleeve according to claim 5, characterized in that: The outer wall of the receiving tube is provided with a ball seat installation groove, the elastic member is a ball seat C-shaped ring, the ball seat C-shaped ring is embedded in the ball seat installation groove, and the ball seat C-shaped ring has elastic force to press against the inner wall of the installation tube.

7. The switchable hydraulic sleeve according to claim 1, characterized in that: The inner wall of the installation tube is provided with a limiting groove, and the outer wall of the receiving tube is provided with a sliding key, and the sliding key is slidably embedded in the limiting groove.

8. The switchable hydraulic sleeve according to claim 7, characterized in that: The limiting groove is annular, and a plurality of latching teeth are formed on the inner wall thereof along the circumferential direction. A plurality of matching teeth are formed on the outer wall of the sliding key along the circumferential direction. The matching teeth are slidably embedded in the latching tooth gaps in a one-to-one correspondence.

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