Expansion type patching pipe made of composite material

Abstract

The utility model discloses a composite expansion type patching pipe which comprises a patching pipe body, a plurality of rings of annular grooves are formed in the outer side wall of the patching pipe, a sealing piece is arranged in each annular groove, and at least one ring of annular protrusion is arranged between every two annular grooves. Wherein the section of the annular bulge is triangular. The outer side wall of the patching pipe is provided with the multiple circles of annular grooves and the triangular annular protrusions, the risk that the sealing pieces are damaged is avoided through blocking of the annular protrusions, and meanwhile the sealing effect of the patching pipe is improved through the multiple circles of sealing pieces.

Description

Technical Field

[0001] The utility model belongs to the field of casing patch, and more specifically, it relates to an expandable patch tube made of composite materials. Background Art

[0002] In the production of gas wells with small-diameter casings, the patched part needs to withstand high pressures (≥50 MPa) during subsequent downhole fracturing without leakage. Ordinary soft metal sealing materials cannot meet such requirements. Although sealing ring grooves are machined on the surface of the patch tube port and rubber sealing rings are installed, high-pressure sealing can be achieved.

[0003] In the prior art, the sealing rings in the sealing ring grooves at the ports of the patch tubes are often scratched and damaged by the inner wall of the casing during downhole transmission, resulting in poor sealing effect and inability to play a sealing role. In addition, the existing structures use patch tubes composed of multiple rings of sealing rings to seal the casing. However, during the process of lowering the patch tube into the well, even with multiple rings of sealing rings, without protection, the sealing rings are prone to being worn or scratched, resulting in poor sealing performance. For example, a patch tube anti-scratching structure disclosed in Patent Application No. CN202323511957.6 has multiple sealing ring grooves on the side wall of the patch tube, and sealing rings with matching specifications are installed in each sealing ring groove to ensure the sealing performance of the sealing rings. However, during the process of the patch tube extending into the well, its side wall will directly rub against the inner wall of the casing, resulting in the failure of multiple rings of sealing rings and unable to achieve the sealing effect. Summary of the Utility Model

[0004] An object of the present utility model is to solve at least the above problems and / or defects and provide at least the advantages described hereinafter.

[0005] To achieve these objects and other advantages of the present utility model, an expandable patch tube made of composite materials is provided, including: a patch tube body, multiple ring grooves are provided on the outer side wall of the patch tube, sealing members are arranged in each ring groove, and at least one ring of annular protrusions is arranged between each ring groove;

[0006] Wherein, the sizes of the ring grooves gradually decrease along the axial direction, the sealing members match the sizes of the corresponding ring grooves, and the cross-section of the annular protrusion is triangular.

[0007] Preferably, each ring groove is provided with a protective layer for fixing the sealing member in the ring groove;

[0008] Wherein, multiple through holes are spaced apart in the middle of the protective layer perpendicular to the axis direction, and multiple through holes form breakable holes along the axis direction of the patch tube.

[0009] Preferably, the sealing member is configured as a rubber sealing ring.

[0010] The utility model has at least the following beneficial effects: by providing multiple annular grooves and triangular annular protrusions on the outer side wall of the subsidy pipe, the risk of seal damage is avoided through the blocking of the annular protrusions, and at the same time, the multiple seals also improve the sealing effect of the subsidy pipe.

[0011] Other advantages, objectives and features of the utility model will be partially reflected by the following description, and partially will also be understood by those skilled in the art through the research and practice of the utility model. Description of the Drawings

[0012] Figure 1 It is a schematic diagram of the overall structure of the subsidy pipe;

[0013] Figure 2 It is a cross-sectional view of the subsidy pipe;

[0014] Figure 3 It is a schematic diagram of the structure of the annular groove, seal and protective layer of the subsidy pipe;

[0015] Reference numerals in the figures: 1. Subsidy pipe, 2. Annular groove, 3. Seal, 4. Annular protrusion, 5. Protective layer, 6. Through hole. Detailed Embodiment

[0016] The following further detailed description of the utility model is provided in conjunction with the drawings, so that those skilled in the art can implement it with reference to the description in the specification.

[0017] It should be understood that the terms such as "having", "comprising" and "including" used herein do not exclude the presence or addition of one or more other elements or their combinations.

[0018] It should be noted that in the description of the present utility model, the orientation or positional relationship indicated by the terms is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0019] In the description of the present utility model, unless otherwise clearly specified and limited, the terms "installed", "provided with", "sheathed / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection, can be a mechanical connection, can be an electrical connection, can be directly connected, or can be indirectly connected through an intermediate medium, and can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0020] In addition, in the present utility model, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0021] As Figure 1 shown, an expandable patch tube made of a composite material includes: a patch tube 1 body, a plurality of rings of grooves 2 are formed on the outer sidewall of the patch tube 1, sealing members 3 are arranged in each ring of groove 2, and at least one ring of annular protrusions 4 is arranged between each ring of groove 2;

[0022] Wherein, the sizes of the rings of grooves 2 decrease in sequence along the axial direction, the sealing members 3 match the sizes of the corresponding rings of grooves 2, and the cross section of the annular protrusions 4 is triangular.

[0023] Working principle:

[0024] During the actual working process, through the triangular annular protrusions 4 arranged between the rings of grooves 2, it is ensured that during the process of the patch tube 1 being lowered into the well, the annular protrusions 4 can block the burrs and dirt inside the casing, so that the sealing members 3 will not be damaged, indirectly protecting the sealing members 3. Through the arrangement of a plurality of rings of sealing members 3 with different sizes, after each sealing member 3 expands, it has an interference fit with the inner sidewall of the casing to different degrees, ensuring that during the use process, even if one layer of the sealing members 3 fails, the sealing member 3 with an outer diameter smaller than it adjacent to it can still work normally to ensure the sealing effect. At the same time, after the triangular annular protrusions 4 expand, they can be inserted into the sidewall of the casing, improving the fixing effect between the patch tube and the casing. And by arranging the sealing members 3 in the rings of grooves 2, the size of the triangular annular protrusions 4 only needs to be 0.5 mm - 0.9 mm larger than the size of the patch tube 1 to ensure the stability of the connection of the annular protrusions 4 after expansion. If the sealing members 3 are directly arranged on the outer wall of the tube body, first, it is not easy to fix the position between the sealing members 3 and the patch tube 1, and second, the size of the annular protrusions 4 needs to be further increased, which will result in that after the patch tube 1 expands, the annular protrusions 4 with too large a size will affect the sealing effect of the sealing members 3.

[0025] In the above technical solution, a protective layer 5 for fixing the sealing members 3 in the rings of grooves 2 is arranged on each ring of groove 2;

[0026] Among them, a plurality of through holes 6 are spaced apart in the middle of the protective layer 5 in a direction perpendicular to the axis, and the plurality of through holes 6 form breakable holes in the axial direction of the patch tube 1. With this technical solution, when the patch tube 1 is lowered into the well, when the seal 3 is not compressed into the annular groove 2 by the protective layer 5, its outer wall protrudes from the outer wall of the corresponding annular groove 2. When the protective layer 5 compresses the seal 3 into the annular groove 2 (the protective layer 5 is connected to the patch tube 1 into an integral structure by hot pressing or bonding), the outer diameter of the patch tube 1 located in the protective layer 5 is the same as the overall outer diameter of the patch tube 1. After the patch tube 1 body undergoes overall plastic expansion, the seal 3 breaks through the breakable holes on the protective layer 5, and the seal 3 bulges out from the protective layer 5 and closely fits the inner wall of the casing.

[0027] In the above technical solution, the seal 3 is configured as a rubber sealing ring. With this technical solution, the rubber sealing ring has good elasticity and compressibility, can closely fit on the inner wall of the casing to form an effective sealing barrier, and at the same time, the rubber material has strong adaptability to temperature, pressure and chemical media and can maintain stable sealing performance within a wide working range.

[0028] Although the embodiments of the present invention have been disclosed above, it is not limited to the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the illustrated and described examples here.

Claims

1. An intumescent patch tube of a composite material, comprising: The subsidy pipe body, wherein multiple rings of annular grooves are formed on the outer side wall of the subsidy pipe, and sealing elements are arranged in each annular groove. It is characterized in that at least one ring of annular protrusions is arranged between each annular groove; Among them, the sizes of the annular grooves decrease in sequence along the axial direction, the sealing elements match the sizes of the corresponding annular grooves, and the cross section of the annular protrusion is triangular.

2. The intumescent patch tube of the composite material according to claim 1, wherein A protective layer for fixing the sealing element in the annular groove is arranged on each annular groove; Among them, multiple through holes are spaced apart in the direction perpendicular to the axis in the middle of the protective layer, and the multiple through holes form a breakable hole along the axis direction of the subsidy pipe.

3. The intumescent patch tube of the composite material according to claim 1, wherein The sealing element is configured as a rubber sealing ring.

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