Shear slip sleeve and work string for staged fracturing of open hole horizontal wells

Abstract

The present application relates to a kind of shear sliding sleeve and process pipe column, shear sliding sleeve includes outer cylinder, mandrel is arranged in the first fluid passage of outer cylinder, one-way valve structure is fixed in the lower end of mandrel, one-way valve structure is sealed with mandrel Connection, one-way valve structure is used to make bottom hole liquid from lower to upper one-way flow into the second fluid passage in mandrel, one-way valve structure is fixed in the first fluid passage by shear pin, and limiting step is arranged in the first fluid passage;Sealing structure is limited on outer cylinder, sealing structure is used to seal the annulus between mandrel and outer cylinder, first bypass hole is opened in the side wall of mandrel, first bypass hole is located above sealing structure before shear pin is cut off, second bypass hole is opened in the side wall of outer cylinder below sealing structure, after mandrel is lowered to lower limit position, first bypass hole and second bypass hole are communicated.Pipe column with the shear sliding sleeve of the present application can be automatically grouted, and without ball can directly test pressure to the sealing of packer.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas extraction technology, specifically relating to a shearing sleeve and a process string for segmented fracturing and stratified extraction in open-hole horizontal wells. Background Technology

[0002] For low-permeability or shale reservoirs, existing open-hole horizontal well staged fracturing technology often employs casing cementing fracturing. After the casing and cementing fracturing sleeves are inserted into the well, cementing is carried out throughout the well. Then, staged fracturing is performed by opening pre-installed fracturing sleeves. During stratified production, the fracturing sleeves at designated strata are opened or closed using switching tools. This type of reservoir has hard geology and a stable wellbore, eliminating the need for sand control screens. For medium-to-high permeability loose sandstone open-hole horizontal well staged fracturing and stratified production technology, a filling sleeve and double-layer screen pipe combined with production and circulation sleeves are generally selected as the sand control string. The screen pipe base pipe does not have single holes. The filling sleeve is used for stratified fracturing. Stratified production is performed by opening or closing pre-installed production and circulation sleeves. At the same time, the production and circulation sleeves are connected to the sand control screens, which can effectively prevent formation sand from entering the wellbore through the production channel.

[0003] In the integrated fracturing and stratified production process for open-hole horizontal wells in medium-to-high permeability loose sandstone, packer setting, ball seat shearing, fracturing sleeve testing, and circulating sleeve closure all require the flushing tubing to withstand pressure. Therefore, the sealing performance of the flushing tubing during the entire fracturing operation determines the quality of the fracturing operation. Simultaneously, the entire sand control tubing string must be able to be flushed and run simultaneously when entering the open-hole formation, facilitating its smooth descent to the designated position. During this simultaneous flushing and running, completion fluid needs to be injected from the drill pipe. This process requires a pressure test of the flushing tubing after connection and before the top packer is connected. During the pressure test, the bottom of the flushing tubing must be sealed, and after the pressure test, the bottom of the flushing tubing must be open. There are generally two methods for pressure testing of the flushing tubing: one is to insert a sealing ball into the bottom of the flushing tubing after the connection is completed, and then backwash the sealing ball out of the flushing tubing after the pressure test is completed. The disadvantage of this method is that the pressure test operation is time-consuming and cumbersome. The other method is to connect a shear ball seat at the bottom of the service tubing string, and then cut the pin of the shear ball seat after the pressure test. During flushing and running, the completion fluid enters the bottom of the sand control tubing string through the bypass hole of the shear ball seat. The disadvantage of this method is that the bypass channel of the shear ball seat is small due to size limitations, which affects the injection rate during flushing and running; the shear ball seat does not have a locking structure, which poses a risk of the ball seat resetting due to bottom pressure. Summary of the Invention

[0004] To address all or part of the aforementioned problems, the present invention aims to provide a shearing sleeve and a process tubing for segmented fracturing and stratified production in open-hole horizontal wells. The process tubing of the present invention can be automatically grouted without the need for grooving while being run into the wellhead; and the sealing performance of the flushing pipe can be directly tested without the need for ball dropping.

[0005] According to one aspect of the present invention, a shearing sleeve is provided, comprising:

[0006] An outer cylinder, wherein a first fluid channel extending from the upper end to the lower end is provided inside the outer cylinder;

[0007] A mandrel is disposed within the first fluid channel, and a second fluid channel extending from the upper end to the lower end is disposed within the mandrel;

[0008] A one-way valve structure is fixed to the lower end of the mandrel and is sealed to the mandrel. The one-way valve structure is used to allow bottom hole fluid to flow unidirectionally from bottom to top into the second fluid channel. The one-way valve structure is fixed in the first fluid channel by a shear pin. A limiting step is provided in the first fluid channel to limit the distance that the mandrel and the one-way valve structure move downward after the shear pin is sheared.

[0009] A sealing structure is provided, which is positioned on the outer cylinder and is used to seal the annular space between the mandrel and the outer cylinder. A first bypass hole is provided on the side wall of the mandrel. Before the shear pin is cut off, the first bypass hole is located above the sealing structure. A second bypass hole is provided on the side wall of the outer cylinder below the sealing structure. After the mandrel moves down to the lower limit position, the first bypass hole and the second bypass hole communicate with each other.

[0010] Furthermore, the one-way valve structure includes a ball seat, which is fixed in the first fluid channel by the shear pin, and the ball seat is fixedly and sealed to the mandrel; the ball seat has a large-diameter hole and a small-diameter hole, the large-diameter hole being located above the small-diameter hole, the large-diameter hole and the small-diameter hole forming a third fluid channel extending from the upper end of the ball seat to the lower end of the ball seat, the third fluid channel communicating with the second fluid channel, a sealing ball and a compression spring being disposed in the large-diameter hole, the diameter of the sealing ball being larger than the diameter of the small-diameter hole, the compression spring being confined in the large-diameter hole, the compression spring being used to cause the sealing ball to block the small-diameter hole.

[0011] Furthermore, a tapered hole is provided between the large-diameter hole and the small-diameter hole, and the compression spring is used to press the sealing ball onto the tapered hole to block the small-diameter hole.

[0012] Furthermore, a support seat is provided between the ball seat and the spindle, and the compression spring is limited by the support seat and the small diameter hole in the large diameter hole. A fourth fluid channel is provided on the support seat, extending from the upper end to the lower end, and the fourth fluid channel connects the second fluid channel above it and the third fluid channel below it.

[0013] Furthermore, the support base includes a support plate and an extension fixedly connected to the lower end of the support plate. The fourth fluid channel extends from the upper end of the support plate to the lower end of the extension. The compression spring is sleeved outside the extension and is limited within the large-diameter hole by the support plate and the small-diameter hole. The support plate is provided with a plurality of third bypass holes, which connect the second fluid channel above it and the third fluid channel below it. The ball seat and the mandrel are fixedly connected by threads, and the ball seat and the mandrel are sealed together by a sealing ring. The inner wall of the mandrel is provided with a mounting groove extending upward from the lower end. The support plate is disposed in the mounting groove, and the support plate is limited within the mounting groove after the mandrel and the ball seat are threadedly connected.

[0014] Furthermore, a fourth bypass hole is provided on the outer cylinder below the limiting step, and the fourth bypass hole connects the annulus outside the outer cylinder and the first fluid channel below the one-way valve structure.

[0015] Furthermore, a locking ring is provided at the upper limit of the inner wall of the outer cylinder. The locking ring and the mandrel cooperate to lock the mandrel after it moves down to the lower limit position.

[0016] Furthermore, the inner wall of the locking ring is provided with a first serrated structure, and the spindle is provided with a second serrated structure. After the spindle moves down to the lower limit position, the spindle is locked by the cooperation of the first serrated structure and the second serrated structure.

[0017] Furthermore, the outer cylinder includes an upper connector, a connecting rod, an intermediate sleeve, a circulation sleeve, and a lower connector. The upper connector is fixedly and sealed to the connecting rod, the connecting rod is fixedly and sealed to the intermediate sleeve, the intermediate sleeve is fixedly and sealed to the circulation sleeve, and the circulation sleeve is fixedly and sealed to the lower connector. A second bypass hole is formed on the circulation sleeve. The sealing structure is limited between the circulation sleeve and the intermediate sleeve. The one-way valve structure is fixed in the first fluid channel of the lower connector by a shear pin. The limiting step is disposed in the first fluid channel of the lower connector. The locking ring is limited between the connecting rod and the intermediate sleeve.

[0018] Furthermore, a sealing structure is provided between the mandrel and the outer cylinder below the second bypass hole; each sealing structure includes a V-shaped packing and a sealing ring, with an upper ring at the upper end and a lower ring at the lower end of each sealing structure.

[0019] The present invention also provides a process string for staged fracturing and layered production in open-hole horizontal wells, including any of the shear sleeves described above.

[0020] As can be seen from the above technical solution, the shearing sleeve and the process string for staged fracturing and layered production in open-hole horizontal wells provided by the present invention have the following beneficial effects:

[0021] Compared with the prior art, the present invention can automatically grout during the lowering of the shearing sleeve and the filling service tool above it, as well as the tubing string above the flushing pipe, without the need for grouting while lowering it from the wellhead; and the sealing performance of the flushing pipe can be tested directly without dropping balls.

[0022] With respect to the shearing sleeve of the present invention, when the shearing pin is sheared, the one-way valve structure and the mandrel move downward together until the first bypass hole and the second bypass hole are aligned, thereby realizing simultaneous flushing and lowering during tubing string insertion; and if well control is encountered during the insertion process, positive pressure can be applied directly to shear the shearing pin, thereby connecting the first bypass hole and the second bypass hole for positive circulation well control.

[0023] This invention, through the cooperation of the locking ring and the mandrel, prevents the mandrel from moving upwards under the pressure at the bottom. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the shearing sleeve before the shearing pin is cut, according to an embodiment of the present invention.

[0025] Figure 2 This is a schematic diagram of the shearing sleeve when the shearing pin is cut off and the mandrel moves down to the lower limit position according to an embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of the support base according to an embodiment of the present invention;

[0027] Figure 4 A schematic diagram of the first serrated structure on the locking ring;

[0028] The attached figures are labeled as follows: upper connector 1, connecting rod 2, locking ring 3, first serrated structure 31, intermediate sleeve 4, upper end ring 5, V-shaped packing 6, sealing ring 7, lower end ring 8, mandrel 9, first bypass hole 91, circulation sleeve 10, second bypass hole 101, support seat 11, third bypass hole 111, fourth fluid channel 112, support plate 113, extension 114, compression spring 12, ball seat 13, sealing ball 14, shear pin 15, lower connector 16, fourth bypass hole 161, sealing ring 17, first fluid channel 18, second fluid channel 19, and third fluid channel 20. Detailed Implementation

[0029] To better understand the purpose, structure, and function of this invention, a shearing sleeve of this invention will be described in further detail below with reference to the accompanying drawings.

[0030] like Figures 1-2 As shown, this illustrates a shearing sleeve according to an embodiment of the present invention, comprising an outer cylinder, a mandrel 9, a one-way valve structure, and a sealing structure. Wherein:

[0031] The outer cylinder has a first fluid channel 18 extending from the upper end to the lower end; the mandrel 9 is disposed within the first fluid channel 18, and a second fluid channel 19 extending from the upper end to the lower end is disposed within the mandrel 9; a one-way valve structure is fixed to the lower end of the mandrel 9, and the one-way valve structure is sealed to the mandrel 9. The one-way valve structure is used to allow the bottom fluid to flow unidirectionally from bottom to top into the second fluid channel 19. The one-way valve structure is fixed within the first fluid channel 18 by a shear pin 15. A limit step is provided within the first fluid channel 18 to limit... The step is used to limit the downward movement of the mandrel 9 and the one-way valve structure after the shear pin 15 is cut off; the sealing structure is limited on the outer cylinder and is used to seal the annular space between the mandrel 9 and the outer cylinder. A first bypass hole 91 is provided on the side wall of the mandrel 9. Before the shear pin 15 is cut off, the first bypass hole 91 is located above the sealing structure. A second bypass hole 101 is provided on the side wall of the outer cylinder below the sealing structure. After the mandrel 9 moves down to the lower limit position, the first bypass hole 91 and the second bypass hole 101 are connected.

[0032] In this embodiment, the outer sleeve of the shearing sleeve is connected to other filling service tools and the tubing string above the flushing pipe. During the tubing string lowering process, the bottom completion fluid, under the action of hydrostatic pressure, pushes open the one-way valve structure and flows into the one-way valve structure from bottom to top. Due to the sealed connection between the one-way valve structure and the mandrel 9, the completion fluid correspondingly enters the second fluid channel 19 of the mandrel 9. At this time, if... Figure 1As shown, the shear pin 15 has not yet been sheared off. The first bypass hole 91 of the mandrel 9 is located above the sealing structure, while the second bypass hole 101 on the outer cylinder is located below the sealing structure. Therefore, as the tubing is lowered, the completion fluid can only move upward to the first bypass hole 91 and fill the inner and outer annulus of the mandrel 9 above the sealing structure through the first bypass hole 91. This process is also the process of the completion fluid being automatically injected into the tubing. Therefore, compared with the prior art, the embodiment of the present invention can automatically grout during the lowering of the shear sleeve and the filling service tool above it, as well as the tubing above the flushing pipe, without the need for grouting while lowering from the wellhead.

[0033] Since the completion fluid is located in the inner and outer annulus of the mandrel 9 above the sealing structure, and the completion fluid gradually increases as the tubing is lowered, the pressure test of the flushing pipe above the shear sleeve is realized accordingly, which prepares for the smooth construction of subsequent open-hole horizontal well segmented fracturing; that is, compared with the prior art, the embodiment of the present invention does not require ball dropping to directly test the sealing performance of the flushing pipe.

[0034] Next, after the pressure test of the pipe is completed, the pressure is further increased. When the internal pressure of the shearing sleeve is increased to the point where the shearing pin 15 is sheared, the one-way valve structure and the spindle 9 move downward together. The lower limit position of the movement of the one-way valve structure and the spindle 9 is the contact position between the one-way valve structure and the limit step. At this time, if... Figure 2 As shown, the first bypass hole 91 on the mandrel 9 and the second bypass hole 101 on the outer cylinder are aligned, and the liquid can flow out through the first bypass hole 91 and the second bypass hole 101 inside the second fluid channel 19 of the mandrel 9, thereby realizing simultaneous flushing and lowering when the tubing is lowered.

[0035] Finally, if well control is encountered during the shearing sleeve and flushing pipe running process in this embodiment of the invention, well control can be achieved by injecting kill fluid through the annulus between the sand control string and the flushing pipe via the blowout preventer and the coupling. Alternatively, the shearing pin 15 can be directly sheared by applying positive pressure, thereby connecting the first bypass hole 91 and the second bypass hole 101 for positive circulation well control.

[0036] In one embodiment, the one-way valve structure includes a ball seat 13, which is fixed in a first fluid channel 18 by a shear pin 15. The ball seat 13 is fixedly and sealed to the spindle 9. A large-diameter hole and a small-diameter hole are provided in the ball seat 13. The large-diameter hole is located above the small-diameter hole. The large-diameter hole and the small-diameter hole form a third fluid channel 20 extending from the upper end of the ball seat 13 to the lower end of the ball seat 13. The third fluid channel 20 communicates with the second fluid channel 19. A sealing ball 14 and a compression spring 12 are provided in the large-diameter hole. The diameter of the sealing ball 14 is larger than the diameter of the small-diameter hole. The compression spring 12 is limited in the large-diameter hole and is used to block the small-diameter hole by the sealing ball 14.

[0037] Specifically, the one-way valve structure includes a ball seat 13, a sealing ball 14, and a compression spring 12. The ball seat 13 is fixed in the first fluid channel 18 of the outer cylinder by a shear pin 15. The ball seat 13 and the mandrel 9 are fixedly sealed together. Therefore, the completion fluid flowing into the one-way valve structure can only enter the second fluid channel 19 of the mandrel 9 and cannot overflow through the ball seat 13 and the mandrel 9. The large-diameter hole and the small-diameter hole in the ball seat 13 form a third fluid channel 20 that runs through the upper and lower ends of the ball seat 13. Therefore, the completion fluid at the bottom, under the action of hydrostatic pressure, pushes open the one-way valve structure and enters the second fluid channel 19 through the third fluid channel 20.

[0038] For the fixed sealing connection between the ball seat 13 and the spindle 9, for example, the ball seat 13 and the spindle 9 are fixedly connected by a threaded structure, and the sealing connection is achieved by a sealing ring 17 provided between the two.

[0039] Furthermore, the compression spring 12 is confined within the large-diameter hole, positioned above the sealing ball 14, and configured to be in a compressed state. The elastic force generated by the compression spring 12 in the compressed state is used to press the sealing ball 14 onto the small-diameter hole, thereby preventing the liquid in the large-diameter hole from flowing backward through the sealing ball 14 from top to bottom. Under the action of the hydrostatic column pressure, the bottom completion fluid can push the sealing ball 14 from bottom to top and enter the second fluid channel 19 of the mandrel 9.

[0040] The specific structure of the one-way valve in this embodiment ensures the smooth progress of the automatic grouting and pressure testing processes.

[0041] A tapered hole is provided between the large-diameter hole and the small-diameter hole. The compression spring 12 is used to press the sealing ball 14 onto the tapered hole to block the small-diameter hole.

[0042] In this embodiment, a tapered hole is provided between the large-diameter hole and the small-diameter hole. The diameter of the tapered hole gradually decreases from top to bottom. Under the elastic force of the compression spring 12, the sealing ball 14 is pressed against the tapered hole. The sealing ball 14 and the tapered hole are rigidly sealed by the tapered surface, so that the liquid cannot flow backward from top to bottom.

[0043] In one embodiment, such as Figure 3 As shown, a support seat 11 is provided between the ball seat 13 and the spindle 9. The compression spring 12 is limited by the support seat 11 and the small diameter hole in the large diameter hole. A fourth fluid channel 112 extending from the upper end to the lower end is provided on the support seat 11. The fourth fluid channel 112 connects the second fluid channel 19 above it and the third fluid channel 20 below it.

[0044] In this embodiment, the compression spring 12 is limited within the large-diameter hole by the support seat 11 above it and the small-diameter hole below it. The support seat 11 is set between the ball seat 13 and the mandrel 9. After the ball seat 13 and the mandrel 9 are fixedly connected, the support seat 11 is limited. In order for the completion fluid to enter the second fluid channel 19 through the third fluid channel 20, the support seat 11 is also provided with a fourth fluid channel 112 that runs through the support seat 11 from top to bottom.

[0045] For limiting the position of the support seat 11, for example, the inner wall of the spindle 9 is provided with a mounting groove extending upward from the lower end, and the support seat 11 is set in the mounting groove. After the spindle 9 and the ball seat 13 are threadedly connected, the support seat 11 is limited in the mounting groove.

[0046] Among them, such as Figure 3 As shown, the support base 11 includes a support plate 113 and an extension 114 fixedly connected to the lower end of the support plate 113. The support plate 113 is disposed in the aforementioned mounting groove, and the support plate 113 is limited in the mounting groove after the spindle 9 and the ball seat 13 are threadedly connected. The fourth fluid channel 112 extends from the upper end of the support plate 113 to the lower end of the extension 114. The compression spring 12 is sleeved on the extension 114 and is limited in the large diameter hole by the support plate 113 and the small diameter hole. The support plate 113 is provided with a plurality of third bypass holes 111, and the third bypass holes 111 connect the second fluid channel 19 above it and the third fluid channel 20 below it.

[0047] In one embodiment, a fourth bypass hole 161 is provided on the outer cylinder below the limiting step. The fourth bypass hole 161 connects the annulus outside the outer cylinder and the first fluid channel 18 below the one-way valve structure.

[0048] In this embodiment, the fourth bypass hole 161 is set on the outer cylinder below the limiting step. During the flushing and downward process, after the liquid flows out through the first bypass hole 91 and the second bypass hole 101, it can flow downward through the annulus outside the outer cylinder to flush the outer cylinder. On the other hand, when the annulus outside the outer cylinder gets stuck, it can also flow downward through the fourth bypass hole 161 from inside the outer cylinder to the outer cylinder.

[0049] In one embodiment, a locking ring 3 is provided at the upper limit of the inner wall of the outer cylinder. The locking ring 3 and the mandrel 9 cooperate to lock the mandrel 9 after it moves down to the lower limit position.

[0050] In this embodiment, the locking ring 3 and the mandrel 9 work together to lock the mandrel 9 after it moves down to the lower limit position. This prevents the mandrel 9 from moving upwards to the first bypass hole 91 and the second bypass hole 101 from becoming disconnected due to excessive bottom pressure. This situation would prevent the tubing from achieving the function of punching and lowering simultaneously when it is lowered. Therefore, the setting in this embodiment ensures the smooth progress of punching and lowering simultaneously.

[0051] Specifically, the inner wall of the locking ring 3 is provided with a first serrated structure 31, and the spindle 9 is provided with a second serrated structure. After the spindle 9 moves down to the lower limit position, the first serrated structure 31 and the second serrated structure cooperate to lock the spindle 9.

[0052] In this embodiment, the locking ring 3 uses a first serrated structure 31 on the locking ring 3 and a second serrated structure on the mandrel 9 to lock the mandrel 9. Specifically, the first serrated structure 31 on the locking ring 3 is as follows: Figure 4 As shown, the second sawtooth structure on the spindle 9 is opposite in direction to the first sawtooth structure 31 on the locking ring 3. After the spindle 9 moves down to the lower limit position, the first sawtooth structure 31 and the second sawtooth structure mesh with each other, and the spindle 9 cannot move upward under the action of bottom pressure.

[0053] In one embodiment, the outer cylinder includes an upper connector 1, a connecting rod 2, an intermediate sleeve 4, a circulation sleeve 10, and a lower connector 16. The upper connector 1 is fixedly and sealed to the connecting rod 2, the connecting rod 2 is fixedly and sealed to the intermediate sleeve 4, the intermediate sleeve 4 is fixedly and sealed to the circulation sleeve 10, and the circulation sleeve 10 is fixedly and sealed to the lower connector 16. In specific implementation, the aforementioned sealing connections are all achieved through a sealing ring 17 disposed between the two, and the aforementioned fixed connections are all achieved through a threaded structure.

[0054] The upper connector 1 is used to connect to the tubing above it, and the second bypass hole 101 is opened on the circulation sleeve 10; the sealing structure is limited between the circulation sleeve 10 and the intermediate sleeve 4; the one-way valve structure is fixed in the first fluid channel 18 of the lower connector 16 by shear pin 15; the limiting step is set in the first fluid channel 18 of the lower connector 16; the locking ring 3 is limited between the connecting rod 2 and the intermediate sleeve 4, and the fourth bypass hole 161 is set on the lower connector 16.

[0055] Regarding the limiting of the locking ring 3, for example, a locking ring mounting hole extending upward from the lower end is provided on the inner wall of the connecting rod 2, and the locking ring 3 is set in the locking ring mounting hole. After the connecting rod 2 is threadedly connected to the intermediate sleeve 4, the locking ring 3 is limited in the locking ring mounting hole. In this case, the upper end of the spindle 9 extends above the locking ring 3, and after the spindle 9 moves down to the lower limit position, the first sawtooth structure 31 and the second sawtooth structure mesh with each other.

[0056] Regarding the sealing structure, as mentioned above, the sealing structure is used to seal the annular space between the mandrel 9 and the outer cylinder. In this embodiment, a sealing structure is also provided between the mandrel 9 and the outer cylinder below the second bypass hole 101.

[0057] For the sealing structure, each sealing structure includes a VV-type packing 6 and a sealing ring 7. Each sealing structure has an upper ring 5 at its upper end and a lower ring 8 at its lower end.

[0058] Compared with the prior art, the embodiments of this invention enable automatic grouting during the running of the shear sleeve, the filling service tool above it, and the tubing string above the flushing pipe, eliminating the need for simultaneous grouting from the wellhead; pressure testing of the flushing pipe's sealing performance can be performed directly without the need for ball dropping; for the shear sleeve in this embodiment, after the shear pin 15 is sheared, the one-way valve structure and the mandrel 9 move downwards together until the first bypass hole 91 and the second bypass hole 101 are aligned, thus achieving simultaneous flushing and running of the tubing string; and if well control is encountered during the running process, positive pressure can be applied directly to shear the shear pin 15, thereby connecting the first bypass hole 91 and the second bypass hole 101 for positive circulation well control. In this embodiment, the locking ring 3 and the mandrel 9 work together to prevent the mandrel 9 from moving upwards under bottom pressure.

[0059] This invention also provides a process tubing for segmented fracturing and stratified production in open-hole horizontal wells, which includes any of the above-mentioned shearing sleeves.

[0060] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0061] Furthermore, the terms "a," "two," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly defined.

[0062] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention 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. These 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 the present invention, and they should all be covered within the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A shearing sleeve, characterized in that, include: An outer cylinder, wherein a first fluid channel extending from the upper end to the lower end is provided inside the outer cylinder; A mandrel is disposed within the first fluid channel, and a second fluid channel extending from the upper end to the lower end is disposed within the mandrel; A one-way valve structure is fixed to the lower end of the mandrel and is sealed to the mandrel. The one-way valve structure is used to allow bottom hole fluid to flow unidirectionally from bottom to top into the second fluid channel. The one-way valve structure is fixed in the first fluid channel by a shear pin. A limiting step is provided in the first fluid channel to limit the distance that the mandrel and the one-way valve structure move downward after the shear pin is sheared. A sealing structure is provided, which is limited on the outer cylinder and is used to seal the annular space between the mandrel and the outer cylinder. A first bypass hole is provided on the side wall of the mandrel. Before the shear pin is cut off, the first bypass hole is located above the sealing structure. A second bypass hole is provided on the side wall of the outer cylinder below the sealing structure. After the mandrel moves down to the lower limit position, the first bypass hole and the second bypass hole communicate with each other. The one-way valve structure includes a ball seat, which is fixed in the first fluid channel by the shear pin and is fixedly and sealed to the mandrel. The ball seat has a large-diameter hole and a small-diameter hole, with the large-diameter hole located above the small-diameter hole. The large-diameter hole and the small-diameter hole form a third fluid channel extending from the upper end of the ball seat to the lower end, communicating with the second fluid channel. A sealing ball and a compression spring are disposed within the large-diameter hole. The diameter of the sealing ball is larger than the diameter of the small-diameter hole, and the compression spring is confined within the large-diameter hole. The compression spring is used to block the small-diameter hole with the sealing ball. A support seat is disposed between the ball seat and the mandrel. The compression spring is confined within the large-diameter hole by the support seat and the small-diameter hole. The support seat has a... A fourth fluid channel extends from the upper end to the lower end, connecting the upper second fluid channel and the lower third fluid channel. The support base includes a support plate and an extension fixedly connected to the lower end of the support plate. The fourth fluid channel extends from the upper end of the support plate to the lower end of the extension. A compression spring is sleeved outside the extension and is limited within the large diameter hole by the support plate and the small diameter hole. The support plate is provided with a plurality of third bypass holes, which connect the upper second fluid channel and the lower third fluid channel. The ball seat and the mandrel are fixedly connected by threads, and the ball seat and the mandrel are sealed together by a sealing ring. The inner wall of the mandrel is provided with a mounting groove extending upward from the lower end. The support plate is disposed in the mounting groove, and the support plate is limited within the mounting groove after the mandrel and the ball seat are threadedly connected. The inner wall of the outer cylinder is provided with a locking ring at its upper limit. The locking ring and the mandrel cooperate to lock the mandrel after it moves down to its lower limit position. The inner wall of the locking ring is provided with a first serrated structure, and the mandrel is provided with a second serrated structure. After the mandrel moves down to its lower limit position, it is locked by the cooperation of the first serrated structure and the second serrated structure. The outer cylinder includes an upper connector, a connecting rod, an intermediate sleeve, a circulation sleeve, and a lower connector. The upper connector is fixedly and sealed to the connecting rod, the connecting rod is fixedly and sealed to the intermediate sleeve, the intermediate sleeve is fixedly and sealed to the circulation sleeve, and the circulation sleeve is fixedly and sealed to the lower connector. A second bypass hole is opened on the circulation sleeve. The sealing structure is limited between the circulation sleeve and the intermediate sleeve. The one-way valve structure is fixed in the first fluid channel of the lower connector by a shear pin. The limiting step is provided in the first fluid channel of the lower connector. The locking ring is limited between the connecting rod and the intermediate sleeve.

2. The shearing sleeve according to claim 1, characterized in that, A tapered hole is provided between the large-diameter hole and the small-diameter hole, and the compression spring is used to press the sealing ball onto the tapered hole to block the small-diameter hole.

3. The shearing sleeve according to claim 1, characterized in that, A fourth bypass hole is provided on the outer cylinder below the limiting step, and the fourth bypass hole connects the annulus outside the outer cylinder and the first fluid channel below the one-way valve structure.

4. The shearing sleeve according to claim 1, characterized in that, A sealing structure is provided between the mandrel and the outer cylinder below the second bypass hole; each sealing structure includes a V-shaped packing and a sealing ring, an upper ring is provided at the upper end of each sealing structure, and a lower ring is provided at the lower end of each sealing structure.

5. A process tubing string for staged fracturing and layered production in open-hole horizontal wells, characterized in that, Includes the shearing sleeve as described in any one of claims 1-4.

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