Layered sliding sleeve with sand prevention function and running along with production pipe column

Abstract

The invention provides a layered sliding sleeve with a sand prevention function along with running of a production pipe column, and relates to the technical field of oil exploitation downhole tools, the layered sliding sleeve comprises a pipe column assembly and a sand prevention screen pipe, the pipe column assembly comprises an inner pipe column and a production sliding sleeve connected with the inner pipe column, and the production sliding sleeve is connected with the inner pipe column; the inner pipe column and the production sliding sleeve are both of a hollow structure, and a center production channel is formed; the sand control screen pipe is arranged on the outer side of the pipe column assembly in a sleeving mode, and an annular space production channel is reserved between the sand control screen pipe and the pipe column assembly. The sand control screen pipe is directly arranged on the outer side of the production sliding sleeve in a sleeving mode, integration of layered sand control and production functions is achieved through one pipe column, the well descending frequency is reduced, and the operation efficiency is improved; the method is especially suitable for the ceramsite migration problem at a multilateral well window, sand prevention production after horizontal well open hole gravel packing, efficient development of a low-permeability reservoir, long-term production of a slight sand production oil well and other working conditions, and the production efficiency and stability of the oil well can be remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of downhole tools technology for oil extraction, and in particular to a layered sliding sleeve with sand-proof function that is lowered into the production tubing string. Background Technology

[0002] In the field of oil and gas extraction, sand control and efficient production in loose sandstone formations, heterogeneous reservoirs, and complex well structures such as branch wells and horizontal wells have always been core technical challenges. Sand particles in these formations are easily transported with oil and gas fluids, which can not only wear downhole equipment such as electric pumps and tubing and block production channels, but also lead to premature well shutdown, significantly increasing well workover costs and production risks.

[0003] Traditional sand control technology typically employs a step-by-step approach, first lowering the sand control pipe column and then the production pipe column. This split design has revealed numerous shortcomings in practical applications.

[0004] First, the phased operation complicates the construction process, significantly prolongs the well completion cycle, and increases operating costs. Secondly, the annulus between the sand control tubing and the production tubing can easily become a channel for sand particle movement, making it difficult to effectively block sand. Furthermore, during the production of branch wells, after the hollow directional perforator is used for directional perforation, the ceramic particles filling the blind section of the branch well will be transported to the electric pump position through the perforation holes during the production of the main well, causing abnormal oil well production.

[0005] Although existing technologies have developed open-hole gravel packing sand control technology for dual-horizontal branch wells, which can largely prevent sand production from loose formations, they still cannot solve the problem of sand entering the oil well from the packing medium or formation sand through the connected perforations.

[0006] Therefore, there is an urgent need for a layered sliding sleeve with sand-proof function that is lowered into the production tubing to solve the above-mentioned technical problems. Summary of the Invention

[0007] The purpose of this invention is to provide a layered sliding sleeve with sand-proof function that is lowered into the production tubing, thereby solving the problems of low operating efficiency and unsatisfactory sand-proof effect caused by the separation of sand-proofing and production tools in the prior art. The various technical effects of the preferred technical solutions provided by this invention are detailed below.

[0008] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a layered sliding sleeve with sand-proof function that is lowered into a production tubing, comprising a tubing assembly and a sand-proof screen, wherein: The tubular assembly includes an inner tubular column and a production sliding sleeve connected to the inner tubular column. Both the inner tubular column and the production sliding sleeve are hollow structures, forming a central production channel. The sand screen tube is fitted onto the outside of the tube column assembly, and an annular production channel is left between the sand screen tube and the tube column assembly.

[0009] Preferably, the inner tubing column includes a first inner tubing column unit and a second inner tubing column unit, wherein: The first inner tube column unit is connected to one side of the production sleeve; The second inner tube column unit is connected to the other side of the production sleeve.

[0010] Preferably, both the first inner tubular column unit and the second inner tubular column unit are configured to be formed by one tubular column or by multiple tubular columns connected sequentially.

[0011] Preferably, the tubing assembly further includes a first connecting end and a second connecting end, wherein: The first connecting end is located at the upper part of the first inner tube column unit; The second connection end is located at the lower part of the second inner tube column unit.

[0012] Both the first and second connection ends include standard API threads.

[0013] Preferably, the tubular assembly further includes a first connector and a second connector, wherein: The first connector is used to connect the first inner tube column unit and the sand-proof screen tube; The second connector is used to connect the second inner tube column unit and the sand screen tube.

[0014] Preferably, both the first connector and the second connector include API standard threads and are provided with stress relief grooves.

[0015] Preferably, the tubing assembly further includes a sealing mechanism, which is disposed between the first connector and the first inner tubing unit, and between the second inner tubing unit and the second connector. The sealing mechanism has an O-ring on its inner side, and the inner cavity of the inner tubing has a 15-30° guide slope.

[0016] Preferably, the sand-proof screen tube is a precision screen tube, comprising a base tube, a stainless steel filter screen, and a protective cover arranged sequentially from the inside to the outside, and the filtration accuracy of the precision screen tube is 50-200μm.

[0017] Preferably, the tubing assembly adopts an X-shaped sliding sleeve design, is forged from 42CrMo alloy steel, and has a pressure bearing capacity of not less than 70MPa.

[0018] Preferably, the sand screen tube and the tube column assembly are fitted with a heat-insertion fit.

[0019] This invention provides a layered sliding sleeve with sand control function that is run along with the production tubing string. The sand control screen is directly fitted onto the outside of the production sliding sleeve and fixed into an integral structure by connectors. A single tubing run integrates layered sand control and production functions, reducing the number of well runs and improving operational efficiency. It effectively solves the problems of complex operations and poor sand control effect in traditional technologies. It is particularly suitable for conditions such as the problem of ceramsite migration at the window of a branch well, sand control production after gravel packing in open holes of horizontal wells, efficient development of low-permeability reservoirs, and long-term production of wells with slight sand production, which can significantly improve the production efficiency and stability of oil wells. Attached Figure Description

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

[0021] Figure 1 This is a schematic diagram of an embodiment of the present invention, which is a layered sliding sleeve with sand-proof function lowered into the production tubing.

[0022] In the figure: 1. First connecting end; 2. First connecting piece; 3. Sealing mechanism; 4. Inner tube column; 41. First inner tube column unit; 42. Second inner tube column unit; 5. Sand screen pipe; 6. Production sliding sleeve; 7. Second connecting piece; 8. Second connecting end. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0024] In the description of this invention, it should be understood that the terms "center," "side," "length," "width," "height," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and "side," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0025] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] Figure 1 This is a structural schematic diagram of this embodiment, as shown below. Figure 1 As shown, this embodiment provides a layered sliding sleeve with sand-proof function that is lowered into the production tubing, including tubing assembly and sand-proof screen 5.

[0027] The tubing assembly includes an inner tubing 4 and a production sleeve 6 connected to the inner tubing 4. Both the inner tubing 4 and the production sleeve 6 are hollow structures, forming a central production channel. The sand screen 5 is fitted on the outside of the tubing assembly, and an annular production channel is left between the sand screen 5 and the tubing assembly to block sand particles and ensure oil production efficiency.

[0028] This system, which involves running a layered sliding sleeve with sand-control function along with the production tubing string, integrates layered sand control and production functions in a single tubing run by directly fitting the sand-control screen 5 onto the outside of the tubing string assembly. This effectively solves the problems of complex operation and poor sand control effect in traditional technologies, reduces the number of well runs, and improves operational efficiency. It is suitable for sand control production operations in branch wells and horizontal wells, and is particularly suitable for solving the problem of ceramic particle migration after directional perforation of hollow directional drilling tools.

[0029] As an optional implementation, the inner tube column 4 includes a first inner tube column unit 41 and a second inner tube column unit 42, wherein the first inner tube column unit 41 is connected to one side of the production sleeve 6; and the second inner tube column unit 42 is connected to the other side of the production sleeve 6.

[0030] In this embodiment, both the first inner tube column unit 41 and the second inner tube column unit 42 are configured to be formed by one tube column or by multiple tube columns connected sequentially. Specifically, in this embodiment, the first inner tube column unit 41 has only one tube column, and the second inner tube column unit 42 is formed by connecting two tube columns. It can be understood that in actual production and use, the first inner tube column unit 41 and the second inner tube column unit 42 can be arranged by connecting an appropriate number of tube columns according to the actual length of use.

[0031] In this embodiment, the first inner tube column unit 41 of the hollow structure is fixed to the production sliding sleeve 6, and the production sliding sleeve 6 is fixed to the second inner tube column unit 42 by a high-strength threaded connection, forming a central production channel.

[0032] As an optional implementation, the tubing assembly further includes a first connecting end 1 and a second connecting end 8, wherein the first connecting end 1 adopts a female tubing thread and is disposed on the upper part of the first inner tubing unit 41; the second connecting end 8 adopts a male tubing thread and is disposed on the lower part of the second inner tubing unit 42. Both the first connecting end 1 and the second connecting end 8 include standard API threads.

[0033] Specifically, in this embodiment, the first connecting end 1 adopts a 2-7 / 8" EU coupling for connecting the upper tubing string; the second connecting end 8 adopts an ACME coupling for connecting the lower tubing string. Both the first connecting end 1 and the second connecting end adopt API standard threads to ensure the reliability of the connection. At the same time, they are universally interchangeable, easy to install and use, and can be adapted to various well conditions.

[0034] As an optional implementation, the tubular assembly further includes a first connector 2 and a second connector 7. The first connector 2 connects the first inner tubular unit 41 and the sand-proof screen 5; the second connector 7 connects the second inner tubular unit 42 and the sand-proof screen 5.

[0035] In this embodiment, both the first connector 2 and the second connector 7 include API standard threads and are provided with stress relief grooves to effectively mitigate the impact of alternating downhole loads and ensure stability during use.

[0036] As an optional implementation, the tubing assembly further includes a sealing mechanism 3. The sealing mechanism 3 employs a sealing retaining ring and is disposed between the first connecting member 2 and the first inner tubing unit 41, and between the second inner tubing unit 42 and the second connecting member 7. The first connecting member 2, the first inner tubing unit 41, the production sliding sleeve 6, the second inner tubing unit 42, and the second connecting member 7 are sequentially connected and fixed by high-strength threads to ensure the stability of the connection. In this embodiment, the sealing mechanism 3 has an O-ring on its inner side, and the inner cavity of the inner tubing 4 has a 15-30° guide slope.

[0037] By placing the sealing mechanism 3 between the first connector 2 and the inner tubing 4, and between the second inner tubing unit 42 and the second connector 7, and using multiple O-rings to achieve multi-stage sealing, long-term production without leakage can be ensured, resulting in better operational stability. The inner tubing 4, as the main body of the tubing assembly, serves as the oil production channel and is preferably made of high-strength, corrosion-resistant material. By providing a 15-30° guide slope within the inner cavity of the inner tubing 4, fluid resistance can be significantly reduced, improving production efficiency.

[0038] In this embodiment, each connecting component is made of 13Ct-18M or 3Ct-180 / 2Ct13 material with high strength and corrosion resistance to ensure stable and reliable use.

[0039] As an optional implementation, the sand-proof screen tube 5 is a precision screen tube made of a high-strength material with adjustable filtration accuracy, used to effectively block sand particles from entering the production channel.

[0040] Specifically, the sand control screen 5 in this embodiment adopts a JMR type precision screen, which includes a base pipe, a stainless steel filter screen, and a protective cover arranged sequentially from the inside to the outside, with a filtration accuracy of 50-200μm. The filtration accuracy of the sand control screen 5 can be flexibly adjusted within the range of 50-200μm, which can adapt to oil wells with different sand production levels, making it more practical.

[0041] As an optional implementation, the tubing assembly in this embodiment adopts an X-type sliding sleeve design, forged from 42CrMo alloy steel, and has a pressure-bearing capacity of not less than 70MPa. The tubing assembly with a pressure-bearing capacity of up to 70MPa supports individual pressure testing to verify its sealing performance.

[0042] As an optional implementation, in this embodiment, the sand screen pipe 5 and the tubular assembly are fitted with a heat-sealed interference fit. The fit tolerance is controlled within the range of H7 / s6, ensuring the reliability and sealing of the connection.

[0043] The process of using the layered sliding sleeve with sand-proof function, which is lowered along with the production tubing, is as follows: A layered sliding sleeve with sand-control function is connected to the production tubing and lowered into the well to the target location in one go. The tubing assembly establishes an oil production channel, while the sand-control screen 5 simultaneously provides sand-blocking functionality. During production, the sand-control screen 5 effectively prevents sand and ceramsite from entering the production channel, ensuring normal well production. Maintenance or adjustments can be made by disassembling the couplings and connecting rods for segmented replacement, making the operation simple.

[0044] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included 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 layered sliding sleeve with sand-proof function that is lowered into the production tubing, characterized in that, Includes tubular assembly and sand screen (5), wherein: The tubular assembly includes an inner tubular column (4) and a production sleeve (6) connected to the inner tubular column (4). Both the inner tubular column (4) and the production sleeve (6) are hollow structures, forming a central production channel. The sand screen tube (5) is fitted onto the outside of the tube column assembly, and an annular production channel is left between the sand screen tube (5) and the tube column assembly.

2. The layered sliding sleeve with sand-proof function lowered with the production tubing as described in claim 1, characterized in that, The inner tubing (4) includes a first inner tubing unit (41) and a second inner tubing unit (42), wherein: The first inner tube column unit (41) is connected to one side of the production sleeve (6); The second inner tube column unit (42) is connected to the other side of the production sleeve (6).

3. The layered sliding sleeve with sand-proof function lowered with the production tubing as described in claim 2, characterized in that, Both the first inner tube column unit (41) and the second inner tube column unit (42) are configured to be formed by one tube column or by connecting multiple tube columns in sequence.

4. The layered sliding sleeve with sand-proof function lowered with the production tubing as described in claim 2 or 3, characterized in that, The tubular assembly further includes a first connecting end (1) and a second connecting end (8), wherein: The first connecting end (1) is located on the upper part of the first inner tube column unit (41); The second connecting end (8) is located at the lower part of the second inner tube column unit (42); Both the first connecting end (1) and the second connecting end (8) include standard API threads.

5. The layered sliding sleeve with sand-proof function lowered with the production tubing as described in claim 2 or 3, characterized in that, The tubular assembly further includes a first connector (2) and a second connector (7), wherein: The first connector (2) is used to connect the first inner tube column unit (41) and the sand screen tube (5); The second connector (7) is used to connect the second inner tube column unit (42) and the sand screen tube (5).

6. The layered sliding sleeve with sand-proof function lowered with the production tubing as described in claim 5, characterized in that, Both the first connector (2) and the second connector (7) include API standard threads and are provided with stress relief grooves.

7. The layered sliding sleeve with sand-proof function lowered with the production tubing as described in claim 6, characterized in that: The tubing assembly also includes a sealing mechanism (3), which is disposed between the first connector (2) and the first inner tubing unit (41), and between the second inner tubing unit (42) and the second connector (7). An O-ring is provided on the inner side of the sealing mechanism (3), and the inner cavity of the inner tubing (4) is provided with a 15-30° guide slope.

8. A layered sliding sleeve with sand-proof function that is lowered into the production tubing according to any one of claims 1-3, characterized in that: The sand-proof screen tube (5) is a precision screen tube, which includes a base tube, a stainless steel filter screen and a protective cover arranged sequentially from the inside to the outside. The filtration accuracy of the precision screen tube is 50-200μm.

9. A layered sliding sleeve with sand-proof function lowered with a production tubing as described in any one of claims 1-3, characterized in that: The tubing assembly adopts an X-type sliding sleeve design and is forged from 42CrMo alloy steel, with a pressure bearing capacity of not less than 70MPa.

10. A layered sliding sleeve with sand-proof function that is lowered into the production tubing according to any one of claims 1-3, characterized in that: The sand screen tube (5) and the tube column assembly are fitted with a heat-insertion fit.

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