Staged cementer device for horizontal wells and downhole devices

Abstract

The application provides a staged cementer device for horizontal wells, comprising a body and a sliding sleeve embedded in the body, a first circulation hole is formed on the body, a second circulation hole is formed on the sliding sleeve, the sliding sleeve is connected with the body through a first shear pin and a second shear pin respectively, wherein in a first state of shearing the first shear pin, the sliding sleeve can be lowered to allow the second circulation hole to be radially aligned with the first circulation hole; in a second state of shearing the second shear pin, the sliding sleeve can continue to be lowered until abutting against the body.

Description

Technical Field

[0001] This invention relates to the field of cementing tools, and more specifically to a staged cementing device for horizontal wells, and a downhole device. Background Technology

[0002] In staged cementing, drill-free staged cementing devices are becoming increasingly widely used because they save on drilling and removal processes. Currently, commonly used drill-free staged cementing devices can be divided into two types: one is the sliding type, which can slide down to the bottom of the well after cementing is completed. Its disadvantage is that it cannot be used in horizontal wells and affects subsequent well bottom operations; the other is the retrieval type, which requires the use of retrieval tools to retrieve the sliding sleeve after cementing is completed, which is costly and has a low retrieval success rate.

[0003] Therefore, it is desirable in the art to provide a staged cementing device and downhole device for horizontal wells to solve the above-mentioned technical problems. Summary of the Invention

[0004] The purpose of this invention is to provide a staged cementing device and downhole device for horizontal wells, which can be applied to horizontal wells without affecting the bottom hole operation process, and at the same time eliminates the need for fishing tools, saving costs, thereby achieving true drill-free removal.

[0005] According to a first aspect of the present invention, a staged cementing device for horizontal wells is provided, comprising a body and a sliding sleeve embedded within the body, wherein a first circulation hole is formed on the body and a second circulation hole is formed on the sliding sleeve, and the sliding sleeve is connected to the body via a first shear pin and a second shear pin, respectively. In the first state where the first shear pin is cut, the sliding sleeve can descend to allow the second circulation hole to be radially aligned with the first circulation hole; in the second state where the second shear pin is cut, the sliding sleeve can continue to descend until it abuts against the body.

[0006] In one embodiment, the first shear pin is secured by a sealing shear pin.

[0007] In one embodiment, the graded cement injector device further includes a first through groove formed on the side wall of the sliding sleeve, and the second shear pin is slidably connected to the first through groove.

[0008] In one embodiment, the graded cement injector device further includes a retaining ring seat disposed on the inner wall of the body, and a retaining ring embedded in the sliding sleeve for fitting with the retaining ring seat.

[0009] In one embodiment, the graded cement injector device further includes a second through groove formed on the side wall of the sliding sleeve, and the retaining ring seat is axially located within the range of the second through groove.

[0010] In one embodiment, a radially arranged vent hole is formed on the side wall of the body, the vent hole communicating with the second through groove, and during assembly, grease needs to be filled into the second through groove through the vent hole.

[0011] In one embodiment, the graded cement injector device further includes a joint disposed above the sliding sleeve, the sliding sleeve abutting against the joint in the initial state.

[0012] In one embodiment, a sealing ring is provided at the junction of the sliding sleeve and the body.

[0013] According to a second aspect of the invention, a downhole apparatus is provided, comprising a filling tool pre-installed in a horizontal well, and a tubing string for connection to the filling tool, the tubing string including a staged cementing device as described above, and a casing section disposed between the staged cementing device and the filling tool.

[0014] In one embodiment, the tubing string further includes a blind flange section disposed below the staged cement injector device, the blind flange section being constructed as a rupture disc, which is flushed out after the blind flange section ruptures.

[0015] Compared with the prior art, the advantages of the present invention are as follows: This application can be applied to horizontal wells without affecting bottomhole operations, and eliminates the need for retrieval tools, saving costs and achieving true drill-free removal. This application features first and second shear pins with different pressure values, allowing the shear pins to be sheared sequentially according to the working order. This allows the sliding sleeve to slide to the right in stages, further completing the opening and closing of the circulation hole. After completing downhole operations, the sliding sleeve retracts into the inner chamber of the main body, thus not occupying the space of the central flow channel of the staged cementing device for horizontal wells, not affecting bottomhole operations, and preventing it from falling downhole, thereby reducing the steps required for retrieval tools in existing technologies. The staged cementing device for horizontal wells of this application has a simple structure, reliable performance, low cost, and can improve production efficiency, thereby enhancing production reliability. Attached Figure Description

[0016] The present invention will now be described in detail with reference to the accompanying drawings.

[0017] Figure 1 The schematic diagram illustrates the structure of a staged cementing device for horizontal wells according to the present invention.

[0018] Figure 2The schematic diagram illustrates the opening state of the staged cementing device for horizontal wells according to the present invention.

[0019] Figure 3 The diagram schematically illustrates the shut-in state of a staged cementing device for horizontal wells according to the present invention.

[0020] Figure 4 The diagram schematically illustrates a wellbore structure adapted to a staged cementing device for horizontal wells according to the present invention.

[0021] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not drawn to scale. Detailed Implementation

[0022] To make the technical solutions and advantages of the present invention clearer, exemplary embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not an exhaustive list of all embodiments. Furthermore, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0023] 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.

[0024] In this invention, unless otherwise explicitly specified and limited, the terms “installation,” “connection,” “linking,” “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.

[0025] Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] Both existing methods have different technical problems. Therefore, in order to address these technical problems, this application proposes a staged cementing device for horizontal wells, which can be applied to horizontal wells without affecting the bottom hole operation process. At the same time, it eliminates the need for fishing tools, saves costs, and achieves true drill-free removal.

[0027] The invention will now be further described with reference to the accompanying drawings.

[0028] like Figure 1As shown, according to a first aspect of the present invention, a staged cementing device 100 for horizontal wells is provided, mainly comprising a body 11, a sliding sleeve 20 embedded within the body 11, and a connector 13 disposed above the body 11. A receiving chamber is formed inside the body 11, the sliding sleeve 20 fills the receiving chamber, and the body 11 axially abuts against the connector 13 in an initial state. In this invention, as... Figure 1 The sliding sleeve 20 shown has a large force-bearing area at its left end (i.e., the upper part) and a small force-bearing area at its right end (i.e., the lower part). Therefore, when the pressure increases to the shear pin pressure value, it will shear the shear pin, thereby enabling the sliding sleeve 20 to slide to the right to complete the work of opening or closing the circulation hole.

[0029] Preferably, the upper female thread of the connector 13 can be processed into different connection thread types according to the type of casing on site, while the lower end of the connector can be connected to the upper end of the body 11 through an airtight thread, thereby improving the robustness and stability of the staged cementing device 100 for horizontal wells of this application.

[0030] In such Figure 1 In the illustrated embodiment, a first circulation hole 111 is formed on the body 11, and a second circulation hole 21 is formed on the sliding sleeve 20. The sliding sleeve 20 is fixedly mounted on the body 11 by a first shear pin 101. Therefore, when the pressure on the upper part of the sliding sleeve 20 increases to the pressure value of the first shear pin 101, the first shear pin 101 will be sheared, and the sliding sleeve 20 will move downward, thereby allowing the second circulation hole 21 of the sliding sleeve 20 to be radially aligned with the first circulation hole 111 of the body 11, so as to achieve the purpose of opening the circulation hole.

[0031] In such Figure 1 In the illustrated embodiment, the staged cementing device 100 for horizontal wells further includes a sealing shear pin 103 arranged radially outside the first shear pin 101. Therefore, the sealing shear pin 103 can seal the rear end of the first shear pin 101, ensuring that the first shear pin 101 can be smoothly sheared at a predetermined position, further ensuring that the staged cementing device 100 for horizontal wells of this application can smoothly carry out subsequent work downhole.

[0032] In such Figure 1In the illustrated embodiment, the sliding sleeve 20 is positioned relative to the body 11 by a second shear pin 102, which is positioned above the first shear pin 101. The staged cementing device 100 for horizontal wells also includes a first through groove 201 formed on the sidewall of the sliding sleeve 20, and the second shear pin 102 is slidably connected to the first through groove 201. Therefore, as the first shear pin 101 is sheared and the sliding sleeve 20 slides downwards, the second shear pin 102 can slide within the first through groove 201 until the first circulation hole 111 is radially aligned, at which point the second shear pin 102 abuts against the upper end of the first through groove 201, thus limiting the sliding distance of the sliding sleeve 20.

[0033] After the cementing work is completed, the pump will be turned on to continue pressurizing. Therefore, when the pressure on the upper part of the sliding sleeve 20 increases to the pressure value of the second shear pin 102, the second shear pin 102 will be sheared, and the sliding sleeve 20 will descend until it comes into contact with the stepped surface 113 of the body 11. At this time, the second circulation hole 21 of the sliding sleeve 20 and the first circulation hole 111 of the body 11 are misaligned to achieve the purpose of closing the circulation hole.

[0034] In this invention, the shear value of the first shear pin 101 is less than that of the second shear pin 102. Therefore, during downhole operations, the first shear pin 101 is sheared first, followed by the second shear pin 102. This helps control the operating sequence of the staged cementing device 100 for horizontal wells, in accordance with the requirements of downhole construction. In one specific embodiment, the shear value of the first shear pin 101 is 6-8 MPa, and the shear value of the second shear pin 102 is 16-18 MPa.

[0035] In such Figure 1 In the illustrated embodiment, the staged cementing device 100 for horizontal wells further includes a retaining ring seat 12 disposed on the inner wall of the body 11, and a retaining ring 22 embedded in the sliding sleeve 20. In the initial state, the retaining ring 22 retracts within the sliding sleeve 20 under the compression of the body 11. Therefore, when both the first shear pin 101 and the second shear pin 102 are sheared and the sliding sleeve 20 abuts against the stepped surface 113 of the body 11, the retaining ring 22 will radially align with the retaining ring seat 12, thereby causing the retaining ring 22 to open outwards to engage with the retaining ring seat 12, effectively preventing the sliding sleeve 20 from retracting, and further improving the robustness and stability of the staged cementing device 100 for horizontal wells of this application.

[0036] like Figures 1-2The diagram shows the first stage of operation of the staged cementing device 100 for horizontal wells. During this process, the pressure on the upper part of the sliding sleeve 20 gradually increases to the pressure value of the first shear pin 101. Therefore, in the first state where the first shear pin 101 is cut, the sliding sleeve 20 will descend to allow the second circulation hole 21 of the sliding sleeve 20 to be radially aligned with the first circulation hole 111 of the body 11, thereby achieving the purpose of opening the circulation hole.

[0037] like Figures 2-3 The diagram shows the second stage of operation of the staged cementing device 100 for horizontal wells. After cementing is completed, the pump is started to continue pressurizing. During this process, the upper part of the sliding sleeve 20 is subjected to pressure that gradually increases to the pressure value of the second shear pin 102. Therefore, in the second state after the second shear pin 102 is cut, the sliding sleeve 20 will descend until it abuts against the stepped surface 113 of the body 11, thereby causing the second circulation hole 21 of the sliding sleeve 20 to be misaligned with the first circulation hole 111 of the body 11, thus achieving the purpose of closing the circulation hole. At the same time, the retaining ring 22 opens outward to engage with the retaining ring seat 12, effectively preventing the sliding sleeve 20 from slipping back.

[0038] After the action of closing the circulation hole is completed, the sliding sleeve 20 will still retract into the receiving chamber inside the body 11. Therefore, it will not occupy the space of the central flow channel of the staged cementing device 100 for horizontal wells, nor will it affect the bottom hole operation process. It will also prevent the device from falling down into the well, thereby reducing the steps of lowering the retrieval tool in the prior art.

[0039] In such Figure 1 In the illustrated embodiment, the staged cementing device 100 for horizontal wells further includes a second through groove 202 formed on the side wall of the sliding sleeve 20, and a breather hole 112 arranged radially on the side wall of the body 11. The second through groove 202 is located below the first through groove 201, and the retaining ring seat 12 is axially positioned within the range of the second through groove 202. The breather hole 112 communicates with the second through groove 202, and during assembly, grease is injected into the second through groove 202 through the breather hole 112. Therefore, this grease filling method ensures that the retaining ring seat 12 remains sealed during downhole operations, thereby ensuring that the retaining ring 22 can smoothly form a stable engagement with the retaining ring seat 12 after it expands outwards, further improving the robustness and stability of the staged cementing device 100 for horizontal wells of this application.

[0040] In such Figure 1 In the illustrated embodiment, sealing rings are provided at the joint between the sliding sleeve 20 and the body 11. For example, the sealing rings can be provided at the top and bottom ends of the sliding sleeve 20, as well as on both sides near the second circulation hole 21, etc. Therefore, this method can ensure the sealing performance between the sliding sleeve 20 and the body 11. In the staged cementing device 100 for horizontal wells of this application, during the opening or closing of the circulation hole, the movement range of the sliding sleeve 20 remains within the receiving chamber inside the body 11. Even after the circulation hole is closed, the sliding sleeve 20 remains inside the body 11 without affecting the intermediate passage or bottom hole operation process. Furthermore, this method eliminates the need for retrieval tools, thereby saving costs and achieving a truly drill-free removal effect.

[0041] like Figure 4 As shown, according to a second aspect of the present invention, a downhole apparatus is provided, including a filling tool 302 pre-installed in a horizontal well 301, and a tubing string for connecting to the filling tool 302. The tubing string includes a staged cementing device 100 for the horizontal well, and a casing short section disposed between the staged cementing device 100 and the filling tool 302. Preferably, the filling tool 302 includes a sealing barrel and a sealing plug. Preferably, a blind flange short section is also provided above the staged cementing device 100 for the horizontal well. The blind flange short section is constructed as a rupture disc structure with a rupture pressure of 23 MPa, and the rupture disc can be flushed out after rupture.

[0042] The complete pipe string structure of the present invention includes, from bottom to top, a plug, a casing short section, a horizontal well mud cake cleaner, a casing short section, a multi-layer stainless steel screen filter pipe, a blind plate short section, an external packer, a staged cementing device 100 for horizontal wells, and casing.

[0043] This invention also includes a slurry design for use with the staged cementing device 100 for horizontal wells. The slurry design includes a primary cementing slurry design and a secondary cementing slurry design. The primary cementing slurry design sequentially includes flushing fluid, isolation fluid, lead slurry, tail slurry, well slurry, protective fluid, and well slurry; the secondary cementing slurry design sequentially includes flushing fluid, isolation fluid, retarder, lead slurry, intermediate slurry, tail slurry, and well slurry, and a special shut-in fluid needs to be injected during shut-in.

[0044] Figure 4 The diagram schematically illustrates a wellbore structure adapted to a staged cementing device for horizontal wells according to the present invention, and Figure 4 The well completion procedure shown includes: wellbore cleaning to the filling tool 302 - circulation to remove mud from the screen pipe - tubing with insertion pipe to the filling tool 302 - insertion pipe to remove mud from the outside of the pipe - high-pressure filling for sand control. The sand control process is as follows: the sealing plug is inserted into the bottom filling server - the well-washing valve sleeve is pushed down - a sealed sand control channel is established - forward sand addition and compression (circulation) reverse filling - the sand control tubing string is lifted 1.5 meters - the well-washing valve sleeve is closed - backwashing the sand in the tubing string - the sand control tubing string is retrieved.

[0045] Compared with existing technologies, the advantages of this invention are: This application can be applied to horizontal wells without affecting the bottomhole operation process, and eliminates the need for retrieval tools, saving costs and achieving true drill-free removal. This application features a first shear pin 101 and a second shear pin 102 with different pressure values, allowing the shear pins to be sheared sequentially according to the working order. This allows the sliding sleeve 20 to slide to the right in stages, further completing the opening and closing of the circulation hole. After completing the downhole operation, the sliding sleeve 20 retracts into the receiving chamber inside the body 11, thus not occupying the space of the central flow channel of the staged cementing device 100 for horizontal wells, not affecting the bottomhole operation process, and preventing it from falling downhole, thereby reducing the steps required for retrieval tools in existing technologies. The staged cementing device 100 for horizontal wells of this application has the advantages of simple structure, reliable performance, low cost, and the ability to improve production efficiency and thus enhance production reliability.

[0046] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art can easily make changes or modifications within the scope of the present invention, and such changes or modifications should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A staged cementing device for horizontal wells, comprising a body (11) and a sliding sleeve (20) embedded in the body (11), wherein a first circulation hole (111) is formed on the body (11), and a second circulation hole (21) is formed on the sliding sleeve (20), wherein the sliding sleeve (20) is connected to the body (11) via a first shear pin (101) and a second shear pin (102), respectively. in, In the first state where the first shear pin (101) is cut off, the sliding sleeve (20) can descend to allow the second circulation hole (21) to be radially aligned with the first circulation hole (111); In the second state after the second shear pin (102) is cut off, the sliding sleeve (20) can continue to descend until it comes into contact with the body (11).

2. The staged cementing device for horizontal wells according to claim 1, characterized in that, The first shear pin (101) is tightened by the sealing shear pin (103).

3. The staged cementing device for horizontal wells according to claim 2, characterized in that, The graded cement injection device further includes a first through groove (201) formed on the side wall of the sliding sleeve (20), and the second shear pin (102) is slidably connected to the first through groove (201).

4. The staged cementing device for horizontal wells according to any one of claims 1 to 3, characterized in that, The graded cement injector device also includes a retaining ring seat (12) disposed on the inner wall of the body (11), and a retaining ring (22) embedded in the sliding sleeve (20) and adapted to the retaining ring seat (12).

5. The staged cementing device for horizontal wells according to claim 4, characterized in that, The graded cement injector device further includes a second through groove (202) formed on the side wall of the sliding sleeve (20), and the snap ring seat (12) is axially located within the range of the second through groove (202).

6. The staged cementing apparatus for horizontal wells according to any one of claims 1 to 3, characterized in that, A vent (112) is formed on the side wall of the body (11) in a radial arrangement. The vent (112) communicates with the second through groove (202). During assembly, grease needs to be filled into the second through groove (202) through the vent (112).

7. The staged cementing apparatus for horizontal wells according to any one of claims 1 to 3, characterized in that, The graded cement injector device also includes a connector (13) disposed above the sliding sleeve (20), the sliding sleeve (20) abutting against the connector (13) in the initial state.

8. The staged cementing apparatus for horizontal wells according to any one of claims 1 to 3, characterized in that, A sealing ring is provided at the joint between the sliding sleeve (20) and the body (11).

9. A downhole apparatus comprising a filling tool (302) pre-installed in a horizontal well (301), and a tubing string for connection to the filling tool (302), the tubing string comprising a staged cementing device according to any one of claims 1 to 8, and a casing short section disposed between the staged cementing device and the filling tool (302).

10. The downhole device according to claim 9, characterized in that, The tubing string also includes a blind flange section disposed below the staged cement injector device. The blind flange section is constructed as a rupture disc and is flushed out after the blind flange section ruptures.

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