Clustered cementing slip sleeve

Abstract

This invention provides a cluster-type cementing sleeve, comprising: a cylindrical body having fracturing holes; an inner sleeve assembly having multiple annular grooves evenly distributed on its inner wall, the inner sleeve assembly being initially fixed to the cylindrical body by a first shear pin and sealing the fracturing holes; an inner sleeve initially fixedly connected to the lower end of the inner sleeve assembly by a second shear pin; and an opening tool comprising a pressure-reducing ball and a clamp, the outer wall of the clamp having multiple annular protrusions corresponding to the annular grooves; wherein, engaging the opening tool allows the annular protrusions to enter the corresponding annular grooves, and by applying pressure, the inner sleeve assembly shears the first shear pin and descends to open the fracturing holes; continued pressure allows the inner sleeve assembly to shear the second shear pin and descend relative to the inner sleeve, causing the lowest annular protrusion to disengage from the corresponding annular groove, thereby allowing the opening tool to pass through this stage of the cluster-type cementing sleeve, where the shear value of the first shear pin is less than the shear value of the second shear pin.

Description

Technical Field

[0001] This invention belongs to the field of well completion technology in the petroleum industry, and specifically relates to a cluster-type cementing sliding sleeve. Background Technology

[0002] In shale gas well completions, horizontal sections typically require staged fracturing. Cementing sleeves are gaining increasing importance due to their significant advantages in achieving targeted fracturing. To achieve fracturing of different sections, existing fracturing tools usually employ ball-dropping to open the sleeve and establish fracturing channels. However, since the number of stages is directly related to the diameter of the fracturing ball, unlimited fracturing is not possible, limiting the number of fracturing stages. Furthermore, each ball drop only opens one sleeve, preventing multi-cluster volumetric fracturing, resulting in low construction efficiency and insufficient reservoir stimulation. Summary of the Invention

[0003] To address the technical problems described above, this invention aims to propose a cluster-type cementing sleeve. This cluster-type cementing sleeve can open multiple cementing sleeves by deploying an opening tool once, achieving infinite segmentation and enabling multi-cluster volumetric fracturing of horizontal well cementing, which can greatly improve single-well production.

[0004] Therefore, according to the present invention, a cluster-type cementing sleeve is provided, comprising: a cylindrical body having fracturing holes; an inner sleeve assembly concentrically arranged within the cylindrical body, the inner wall of the inner sleeve assembly having a plurality of annular grooves spaced axially from each other, the inner sleeve assembly being initially fixed to the cylindrical body by a first shear pin and sealing the fracturing holes; an inner sleeve disposed at the lower end of the inner sleeve assembly, the inner sleeve being initially fixed to the inner sleeve assembly by a second shear pin; and an opening tool, the opening tool comprising a pressure-reducing ball and a clamp, the outer wall of the clamp having a... Multiple annular protrusions corresponding to the annular grooves; wherein, when the opening tool is inserted, the annular protrusions can enter the corresponding annular grooves, and the inner sleeve assembly is driven to cut the first shear pin and move downward by the pressure-pressurizing ball to open the fracturing hole. Continued pressure can cause the inner sleeve assembly to cut the second shear pin and move downward relative to the inner sleeve, and cause the lowest annular protrusion to disengage from the corresponding annular groove, thereby allowing the opening tool to pass through the cluster cementing sleeve of this stage, where the shear value of the first shear pin is less than the shear value of the second shear pin.

[0005] In one embodiment, the axial width of the annular groove is greater than the axial width of the annular protrusion.

[0006] In one embodiment, the inner sleeve assembly includes an inner sliding sleeve and an elastic claw fixedly connected to the lower end of the inner sliding sleeve, wherein the inner sleeve is initially fixed to the elastic claw by a second shear pin.

[0007] In one embodiment, the outer surface of the elastic claw is provided with elastic claw external teeth, and the inner wall of the cylindrical body is provided with body internal teeth. The elastic claw external teeth can be adapted to mesh with the body internal teeth to prevent the inner sleeve assembly from retracting.

[0008] In one embodiment, a lower connector is fixedly connected to the lower end of the cylindrical body, and the upper end face of the lower connector extends into the interior of the cylindrical body to form a first limiting step for limiting the inner sleeve assembly.

[0009] In one embodiment, the inner wall of the lower connector is provided with a second limiting step with its end face facing upward, which is used to limit the inner sleeve.

[0010] In one embodiment, the inner wall of the elastic claw is provided with a first inner step facing downwards, and a first annular groove at the lowest end is formed between the first inner step and the upper end face of the inner sleeve. The lower end sidewall of the first annular groove is constructed as a first conical surface.

[0011] The lower end face of the first annular protrusion at the lowest end of the clamp is constructed as a second conical surface, and the first annular protrusion can enter the first annular groove and can be dislodged from the first annular groove under the action of the conical surface.

[0012] In one embodiment, the inner wall of the inner sliding sleeve is provided with a second inner step facing downwards, a retaining ring is provided between the inner sliding sleeve and the elastic claw, and a second annular groove adjacent to the first annular groove is formed between the upper end face of the second inner step and the retaining ring.

[0013] The lower end face of the second annular protrusion adjacent to the first annular protrusion on the clamping cylinder is a first plane, and the lower side wall of the second annular groove is a second plane. The clamping cylinder can be adapted to the first annular groove through the second annular protrusion to transmit axial force, and when the first annular protrusion is dislodged from the first annular groove, it can drive the second annular protrusion to dislodge from the second annular groove.

[0014] In one embodiment, the clamp is provided with a plurality of through slots extending axially, and the plurality of through slots are evenly spaced apart in the circumferential direction.

[0015] In one embodiment, the upper end of the cylindrical body is fixedly connected to an upper connector for connecting the upper tube string.

[0016] Compared with the prior art, the advantages of this application are:

[0017] The cluster-type cementing sleeve of the present invention can open multiple cementing sleeves with a single deployment of the opening tool, thereby enabling infinitely segmented fracturing and multi-cluster volumetric fracturing of horizontal wells. This significantly improves operational efficiency and greatly increases single-well production. The cluster-type cementing sleeve is simple to operate and has a straightforward construction process, making it very convenient for construction operations. Furthermore, after the fracturing hole is opened, it prevents the inner sleeve assembly from retracting and closing the fracturing hole due to bottom hole pressure, effectively ensuring the reliable execution of subsequent operations. Attached Figure Description

[0018] The present invention will now be described with reference to the accompanying drawings.

[0019] Figure 1 The structure of the cluster cementing sleeve according to the present invention is shown.

[0020] Figure 2 schematically shown Figure 1 The state of the cluster-type cementing sleeve when the opening tool is not engaged.

[0021] Figure 3 schematically shown Figure 1 The structure of the opening tool in the cluster-type cementing sleeve described in the article.

[0022] Figure 4 The diagram schematically shows the state of the fracturing hole when it is open.

[0023] Figure 5 The diagram illustrates the state when the clamp is disengaged.

[0024] Figure 6 The illustration shows the status after the tool has been opened.

[0025] Figure 7 yes Figure 5 A magnified view of region A in the middle.

[0026] In this application, all drawings are schematic and are used only to illustrate the principles of the invention, and are not drawn to scale. Detailed Implementation

[0027] The present invention will now be described with reference to the accompanying drawings. It should be noted that these descriptions are provided merely to illustrate the principles of the invention and do not limit the scope of the invention.

[0028] For ease of understanding, in this application, the end closest to the wellhead is defined as the upper end, upstream end, or similar terms, for example... Figure 1 The left end is defined as the end furthest from the wellhead, while the end furthest from the wellhead is defined as the lower end, downstream end, or similar terms, for example... Figure 1The right end of the middle. Meanwhile, the direction along the length of the cluster cementing sleeve is referred to as the longitudinal direction, axial direction, or similar terminology, while the direction perpendicular to it is referred to as the transverse direction, radial direction, or similar terminology.

[0029] Figure 1 The structure of the clustered cementing sleeve 100 according to the present invention is shown. Figure 1 As shown, the cluster-type cementing sleeve 100 includes a cylindrical body 2, an inner sleeve assembly 5, an inner sleeve 10, and an opening tool 3. The cylindrical body 2 has a fracturing hole 21 penetrating its sidewall, preferably located near the upper end of the cylindrical body 2. The inner sleeve assembly 5 is concentrically arranged inside the cylindrical body 2, and its inner wall has multiple annular grooves spaced axially from each other. In the initial state, the inner sleeve assembly 5 is fixed to the cylindrical body 2 by a first shear pin 4 and seals the fracturing hole 21. The inner sleeve 10 is fixedly connected to the lower end of the inner sleeve assembly 5, and in the initial state, the inner sleeve 10 is fixed to the inner sleeve assembly 5 by a second shear pin 9. The opening tool 3 includes a clamp 6 and a pressure ball 30. The outer wall of the clamp 6 has multiple annular protrusions that correspond to the annular grooves.

[0030] During the operation, by deploying the opening tool 5, the annular protrusion can be made to enter the corresponding annular groove, and by pressurizing the pressure ball 30, the inner sleeve assembly 5 can be driven to cut the first shear nail 4 and move downward to open the fracturing hole 21. By continuing to pressurize, the inner sleeve assembly 5 can cut the second shear nail 9 and move downward relative to the inner sleeve 10, and the annular protrusion at the lowest end can be dislodged from the corresponding annular groove, so that the opening tool 5 can pass through the stage cluster cementing sleeve 100.

[0031] According to the present invention, the shear value of the first shear pin 4 is less than the shear value of the second shear pin 9.

[0032] The axial width of each annular groove is greater than the axial width of the corresponding annular protrusion. This not only facilitates the annular protrusion entering the corresponding annular groove, but also provides a movable space for relative movement between the inner sleeve assembly 5 and the opening tool 3.

[0033] like Figure 2 As shown, the inner sleeve assembly 5 includes an inner sliding sleeve 51 and an elastic claw 52 fixedly connected to the lower end of the inner sliding sleeve 5. In its initial state, the inner sleeve 10 is fixed to the elastic claw 52 by a second shear pin 9. In one embodiment, the elastic claw 52 is connected to the inner sleeve 10 via a stepped joint and fixed by threads.

[0034] According to one embodiment of the present invention, an external tooth 520 is provided on the outer surface of the elastic claw 52, ​​and the external tooth 520 is preferably located near the lower end of the elastic claw 52. Simultaneously, an internal tooth 22 is provided on the inner wall of the cylindrical body 2, and the internal tooth 22 is located near the lower end of the cylindrical body 2. The downward movement of the inner sleeve assembly 5 allows the external tooth 520 to engage with the internal tooth 22, preventing the inner sleeve assembly 5 from retracting.

[0035] like Figure 2 As shown, a lower connector 11 is fixedly connected to the lower end of the cylindrical body 2 for connecting a lower tube string (not shown). In one embodiment, the lower connector 11 is connected to the cylindrical body 2 via a stepped connecting buckle and fixedly connected via a threaded connection. The upper end face of the lower connector 11 extends into the interior of the cylindrical body 2 to form a first limiting step 112, which is used to limit the axial movement of the inner sleeve assembly 5. To ensure the sealing of the connection between the lower connector 11 and the cylindrical body 2, a sealing element can be provided between the connection surfaces of the lower connector 11 and the cylindrical body 2.

[0036] The inner wall of the lower connector 11 is provided with a second limiting step 113 with the end face facing upward, which is used to limit the axial direction of the inner sleeve 10.

[0037] According to the present invention, the inner wall of the elastic claw 52 is provided with a first inner step 522 facing downward. A first annular groove 53 at the lowest end is formed between the first inner step 522 and the upper end face of the inner sleeve 10, and the upper end face of the inner sleeve 10 is constructed as a first conical surface 531. At the same time, the lower end face of the first annular protrusion 33 at the lowest end on the clamping sleeve 32 is constructed as a second conical surface 331, and the first annular protrusion 33 can enter the first annular groove 53 and can disengage from the first annular groove 53 under the action of the conical surface.

[0038] like Figure 2As shown, a second inner step 511 with its end face facing downwards is provided on the inner wall of the inner sliding sleeve 51. A retaining ring 7 is provided between the inner sliding sleeve 51 and the elastic claw 52. Preferably, the retaining ring 7 is fixedly installed axially between the stepped joint of the inner sliding sleeve 51 and the elastic claw 52. A second annular groove 54 adjacent to the first annular groove 53 is formed between the upper end face of the second inner step 511 and the retaining ring 7, and the second annular groove 54 is located at the upper end of the first annular groove 53. The upper end face of the retaining ring 7 is constructed as a plane, thereby forming the lower side wall surface of the second annular groove 53 as a second plane 71. At the same time, the lower end face of the second annular protrusion 34 on the clamping cylinder 32, which is adjacent to the first annular protrusion 33, is a first plane 341, and the second annular protrusion 34 is located at the upper end of the first annular protrusion 33. The clamping cylinder 32 can transmit axial force by adapting the second annular protrusion 34 to the corresponding side wall plane structure of the first annular groove 53. Furthermore, when the first annular protrusion 33 disengages from the first annular groove 53, the outer cylinder 32 can drive the second annular protrusion 34 to disengage from the second annular groove 53.

[0039] exist Figure 2 In the illustrated embodiment, the inner wall of the inner sleeve 51 is further provided with a third annular groove 55, which is located above the second annular groove 54, and the lower side wall of the third annular groove 54 is a conical surface. Meanwhile, as... Figure 3 As shown, the outer surface of the clamp 32 is also provided with a third annular protrusion 35, which is located above the second annular protrusion 34.

[0040] Figure 3 The structure of opening tool 3 is illustrated schematically. For example... Figure 3 As shown, the clamp 32 has multiple axially extending through slots 311, the two ends of which terminate at the axial inner sides of both ends of the clamp 32. The multiple through slots 311 are evenly spaced apart in the circumferential direction. This structure of the clamp 32 particularly facilitates radial deformation of the clamp 32, ensuring the reliability of the opening tool 3. The upper end of the clamp 32 is constructed as an arc-shaped ball seat for fitting with the pressure ball 31.

[0041] According to the present invention, an upper connector 1 is fixedly connected to the upper end of the cylindrical body 2. The upper connector 1 is used to connect to the upper tube string (not shown). In one embodiment, the upper connector 1 is connected to the cylindrical body 2 by a stepped connecting buckle and fixedly connected by a threaded connection. To ensure the sealing of the connection between the upper connector 1 and the cylindrical body 2, a sealing element can be provided between the connection surfaces of the upper connector 1 and the cylindrical body 2.

[0042] To ensure the sealing of the fracturing hole 21 in the initial state, at least two dynamic seals are provided between the cylindrical body 2 and the inner sliding sleeve 51, which are spaced apart from each other in the axial direction. The fracturing hole 21 is located between the dynamic seals in the initial state, which can effectively ensure the sealing of the fracturing hole 21.

[0043] The working process of the cluster cementing sleeve 100 according to the present invention is briefly described below. First, the cluster cementing sleeve 100, excluding the opening tool 3, is connected to the completion tubing string and lowered into the wellbore until the target formation is reached. At this time, as Figure 2 As shown, the cluster cementing sleeve 100 is in its initial state. In this state, the inner sleeve 51 in the inner sleeve assembly 5 is fixedly connected to the cylindrical body 2 via the first shear pin 4, and the fracturing hole 21 is sealed, thereby closing the cluster cementing sleeve 100. At the same time, the inner sleeve 10 is fixedly connected to the lower end of the elastic claw 52 via the second shear pin 9, and the outer teeth 520 of the elastic claw at the lower end of the elastic claw 52 are located above the inner teeth 22 of the body and separated by a distance. The lower end face of the inner sleeve 10 is also separated by a distance from the second limiting step 113 of the inner wall of the lower connector 11.

[0044] When fracturing operations are required, the opening tool 3 is deployed from the wellhead. The clamp 32 of the opening tool 3 descends until the first annular protrusion 33, the second annular protrusion 34, and the third annular protrusion 35 respectively enter the corresponding first annular groove 53, second annular groove 54, and third annular groove 55 on the inner wall of the inner sleeve assembly 5, and the lower end face of each annular protrusion contacts the lower side wall surface of the corresponding annular groove. Figure 1 As shown, when the tool 3 is opened and the inner sleeve assembly 5 is fitted, since the axial width of each annular groove is greater than the axial width of the corresponding annular protrusion, there is a movable space between the upper end face of each annular protrusion and the upper side wall of the corresponding annular groove.

[0045] Then, by pressurizing the wellhead, the pressure-blocking ball 31 and the clamp 32 are adapted to block pressure, and a pressure difference is formed on the upper and lower sides of the pressure-blocking ball 31. As the pressure difference continues to increase, the clamp 32 drives the inner sleeve assembly 5 and the inner sleeve 10 to cut the first shear nail 4 and descend until the fracturing hole 21 is opened to provide a fracturing channel. Figure 4 The open state of fracturing hole 21 is shown.

[0046] After the fracturing hole 21 is opened, pressure continues to be applied through the wellhead before the outer cement sheath of the cluster cementing sleeve 100 is broken, and the inner sleeve assembly 5 and the inner sleeve 10 continue to descend as a whole. When the lower end face of the inner sleeve 10 contacts the second limiting step 113 on the inner wall of the lower connector 11, the second limiting step 113 forms an axial limit on the inner sleeve assembly 5 as a whole. At this time, the outer teeth 521 of the elastic claw are at the upper end of the inner teeth 22 of the body, and the two are not engaged. The upper end of the inner sleeve 51 of the inner sleeve assembly 5 is continuously increased by the pressure, thereby pushing the inner sleeve assembly 5 until it shears the second shear pin 9, and the inner sleeve assembly 5 descends, so that the lower end face of the elastic claw 52 contacts the upper end face of the lower connector 11. When the elastic claw 52 reaches the upper end face of the lower connector 11, as the elastic claw 52 moves axially closer to the inner sleeve 10, the upper and lower side walls of the first annular groove 53 move closer to each other, so that the first annular groove 53 forms axial pressure on the axial side wall of the first annular protrusion 33. Figure 7 As shown, since the upper end face of the inner sleeve 10 is the first conical surface 531, and the lower end face of the first annular protrusion 33 is the second conical surface 331 (see... Figure 3 Thus, under the action of the conical surface, the first annular protrusion 33 is squeezed out from the first annular groove 53 under the action of axial force, and the clamp 32 is radially contracted inward. This causes the second annular protrusion 34 and the third annular protrusion 35 on the clamp 32 to disengage from the corresponding second annular groove 54 and third annular groove 55, ultimately allowing the opening tool 3 to pass through this stage to open the cluster cementing sleeve 100. At the same time, when the elastic claw 52 moves to the point where the outer teeth 520 of the elastic claw and the inner teeth 22 of the body are adapted to mesh, it can prevent the inner sleeve assembly 5 from retracting under the action of bottom hole pressure and closing the fracturing hole 21, ensuring the reliable progress of subsequent fracturing operations. Figure 6 The illustration shows the status after opening tool 3.

[0047] According to the present invention, the pressure ball 31 and the clamp 32 are preferably made of soluble material, which can eliminate the need for later drilling and removal and achieve large-diameter well completion of the tubing string.

[0048] The cluster-type cementing sleeve 100 of the present invention can open multiple cementing sleeves by deploying the opening tool 3 once, thereby enabling infinitely segmented fracturing and multi-cluster volumetric fracturing of horizontal wells. This significantly improves operational efficiency and greatly increases single-well production. The cluster-type cementing sleeve 100 is simple to operate and has a simple construction process, making it very convenient for construction operations. Furthermore, after the fracturing hole 21 is opened, it can prevent the inner sleeve assembly 5 from retracting and closing the fracturing hole 21 due to the bottom hole pressure, effectively ensuring the reliable progress of subsequent operations.

[0049] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0050] In this invention, unless otherwise explicitly 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 connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0051] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A cluster-type cementing sliding sleeve, comprising: A cylindrical body (2) is provided with a fracturing hole (21). The inner sleeve assembly (5) is concentrically arranged inside the cylindrical body. The inner wall of the inner sleeve assembly is provided with a plurality of annular grooves that are axially spaced apart from each other. In the initial state, the inner sleeve assembly is fixed to the cylindrical body by the first shear pin (4) and seals the fracturing hole. An inner sleeve (10) is disposed at the lower end of the inner sleeve assembly, and the inner sleeve is initially fixed to the inner sleeve assembly by a second shear pin (9); and The opening tool (3) includes a pressure ball (31) and a clamp (32). The outer wall of the clamp is provided with a plurality of annular protrusions that correspond to the annular groove. The deployment of the opening tool allows the annular protrusion to enter the corresponding annular groove. Pressure is then applied by the pressure-absorbing ball, causing the inner sleeve assembly to shear the first shear pin and descend, thus opening the fracturing hole. Continued pressure allows the inner sleeve assembly to shear the second shear pin and descend relative to the inner sleeve, causing the lowest annular protrusion to disengage from the corresponding annular groove. This allows the opening tool to pass through this stage of the cluster cementing sleeve and enter the next stage of the cluster cementing sleeve. The shear value of the first shear pin is less than the shear value of the second shear pin. The inner sleeve assembly includes an inner sliding sleeve (51) and an elastic claw (52) fixedly connected to the lower end of the inner sliding sleeve. In the initial state, the inner sleeve is fixed to the elastic claw by a second shear pin (9). The outer surface of the elastic claw is provided with elastic claw outer teeth (521), and the inner wall of the cylindrical body is provided with body inner teeth (22). The elastic claw outer teeth can be adapted to mesh with the body inner teeth to prevent the inner sleeve assembly from retracting.

2. The cluster-type cementing sliding sleeve according to claim 1, characterized in that, The axial width of the annular groove is greater than the axial width of the annular protrusion.

3. The cluster-type cementing sliding sleeve according to claim 2, characterized in that, A lower connector (11) is fixedly connected to the lower end of the cylindrical body. The upper end face of the lower connector extends into the interior of the cylindrical body to form a first limiting step (112) for limiting the inner sleeve assembly.

4. The cluster-type cementing sliding sleeve according to claim 3, characterized in that, The inner wall of the lower connector is provided with a second limiting step (113) with the end face facing upward, which is used to limit the inner sleeve.

5. The cluster-type cementing sliding sleeve according to claim 2, characterized in that, The inner wall of the elastic claw is provided with a first inner step (522) with the end face facing downward. A first annular groove (53) at the lowest end is formed between the first inner step and the upper end face of the inner sleeve. The lower end side wall of the first annular groove is constructed as a first conical surface (531). The lower end face of the first annular protrusion (33) at the lowest end of the clamp is constructed as a second conical surface (331), and the first annular protrusion can enter the first annular groove and can be dislodged from the first annular groove under the action of the conical surface.

6. The cluster-type cementing sliding sleeve according to claim 5, characterized in that, The inner wall of the inner sliding sleeve is provided with a second inner step (511) with the end face facing downward. A retaining ring (7) is provided between the inner sliding sleeve and the elastic claw. A second annular groove (54) adjacent to the first annular groove is formed between the upper end face of the second inner step and the retaining ring. The lower end face of the second annular protrusion (34) adjacent to the first annular protrusion on the clamp is a first plane (341), and the lower side wall of the second annular groove is a second plane (71). The clamp can be adapted to the first annular groove through the second annular protrusion to transmit axial force, and when the first annular protrusion comes out of the first annular groove, it can drive the second annular protrusion to come out of the second annular groove.

7. The cluster-type cementing sliding sleeve according to claim 1, characterized in that, The clamp is provided with a plurality of through slots (311) extending along the axial direction, and the plurality of through slots are evenly spaced apart in the circumferential direction.

8. The cluster-type cementing sliding sleeve according to claim 1, characterized in that, The upper end of the cylindrical body is fixedly connected to an upper connector (1) for connecting the upper tube string.

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