Dissoluble expansion plugging ball for under-pressure emergency repair of non-metal composite pipe and emergency repair method

Abstract

The invention relates to the fields of petroleum, chemical engineering, water supply and drainage and the like, in particular to a dissoluble expansion plugging ball for under-pressure emergency repair of a non-metal composite pipe and an emergency repair method. The inner framework layer wraps the outer side of the soluble counterweight head and is used for expanding and supporting outwards after the external pressure of the soluble counterweight head is reduced; the middle expansion layer is arranged on the outer side of the inner framework layer and used for wrapping the inner framework layer, and the middle expansion dissolving layer expands after encountering liquid and is gradually dissolved after expansion; the outer dissolution layer is arranged on the outer side of the middle expansion dissolution layer and used for wrapping the middle expansion dissolution layer, and the outer dissolution layer is gradually dissolved after encountering liquid. The plugging ball has the beneficial effects that after the plugging ball is arranged in a water pipe or an oil pipe, expansion can be rapidly achieved, a pipeline is plugged, the situation that transportation stopping and pressure relief are needed is avoided, the maintenance time of the pipeline is greatly shortened, production interruption loss caused by pipeline maintenance is reduced, and secondary cleaning is avoided.

Description

Technical Field

[0001] This invention relates to the fields of petroleum, chemical industry, water supply and drainage, and in particular to a dissolvable expansion plugging ball and repair method for live repair of non-metallic composite pipes. Background Technology

[0002] Non-metallic composite pipes (such as reinforced thermoplastic composite pipes (RTP) and fiber-reinforced composite pipes (FRP)) are widely used in oil and gas transportation, urban water supply, and other fields. Traditional pipeline maintenance methods require emptying the medium from the pipeline and stopping its operation, a process that can cause huge economic losses. For example, the hourly loss from shutting down an oil and gas pipeline can reach hundreds of thousands of yuan.

[0003] Existing leak-sealing methods have many limitations. Conventional leak-sealing methods (such as clamping, clamping, and pipe cutting and replacement) usually require depressurization of the pipeline first, and the operation process is complex. Due to the easily deformable nature of non-metallic pipelines, mechanical leak-sealing methods are difficult to adapt well and cannot guarantee a good sealing effect. Traditional leak-sealing balls (such as rubber leak-sealing balls) need to be removed from the pipeline manually or mechanically after completing the leak-sealing task. This process is not only cumbersome, but also difficult to operate in long-distance or complex pipelines, and is prone to pipeline blockage, bringing secondary maintenance risks.

[0004] Furthermore, non-degradable sealing materials, if left inside pipelines, may cause media pollution and even safety accidents under certain circumstances. For example, CN103820088A discloses a sustainable expanding sealing agent composed of vermiculite, rice husks, nut shells, mica flakes, plant fibers, polyacrylamide gel particles, and water. While suitable for pipeline sealing, this agent is entirely composed of organic materials and does not degrade after sealing, making it inconvenient to remove after repairs. Another example is CN105238375B, which discloses a high-strength self-expanding sealing agent composed of oil well cement, aluminum powder, calcium oxide, asbestos fiber, foam stabilizer, and retarder. This agent exhibits good fluidity upon injection and a high expansion coefficient and strength after penetration. However, it is difficult to dissolve after expansion, making it inconvenient to remove after repairs and unsuitable for pipeline maintenance. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a dissolvable expansion plugging ball and a repair method for live repair of non-metallic composite pipes, which can achieve rapid sealing under pressure and can automatically dissolve later, adapting to rapid repair of various pipe diameters and pipe materials.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a soluble expansion plugging ball for emergency repair of non-metallic composite pipes under pressure, comprising a soluble counterweight head; An inner skeleton layer, which wraps around the outside of the soluble counterweight head, is used to expand outward for support after the external pressure decreases. An intermediate expansion and dissolution layer is provided on the outside of the inner skeleton layer to wrap the inner skeleton layer. The intermediate expansion and dissolution layer expands upon contact with liquid and gradually dissolves after expansion. An outer dissolving layer is provided outside the intermediate expanding dissolving layer to wrap around it. The outer dissolving layer gradually dissolves upon contact with a liquid.

[0007] The beneficial effects of this invention are: after the plugging ball is placed inside the water pipe or oil pipe, it can quickly expand and seal the pipe, avoiding the need to stop the flow and release pressure, greatly shortening the pipe maintenance time and reducing production interruption losses caused by pipe maintenance; and after the pipe maintenance is completed, it can dissolve on its own, avoiding secondary cleaning and not causing pollution to the fluid in the pipe.

[0008] Based on the above technical solution, the present invention can be further improved as follows.

[0009] Furthermore, the soluble counterweight is a magnesium-aluminum alloy, and the mass percentage of the components of the magnesium-aluminum alloy is: magnesium 80%-88%, zinc 4%-7%, and regulating elements 5%-13%.

[0010] The beneficial effects of adopting the above-mentioned further solution are: magnesium-zinc alloy is a soluble alloy, which is used in pipeline maintenance as a sealing tool to guide the plugging ball to move directionally in the pipeline so that it can accurately reach the leak point. After completing the task, it can quickly dissolve in a specific liquid environment, avoiding secondary recycling.

[0011] Furthermore, the regulating element is one or more of aluminum, copper, nickel, yttrium, silicon, manganese, cobalt, chromium, and iron.

[0012] The beneficial effects of adopting the above-mentioned further scheme are as follows: Aluminum, copper, nickel, yttrium, silicon, manganese, cobalt, chromium, and iron, as regulating elements in magnesium-zinc alloys, each have different functions. Different regulating elements can be selected according to actual needs. Specifically: Aluminum improves the strength and hardness of the alloy, enhances casting performance, and strengthens corrosion resistance; copper significantly improves the strength and heat resistance of the alloy and promotes the precipitation of age-hardening phases; nickel improves the corrosion resistance of the alloy, enhances high-temperature performance, and stabilizes the alloy microstructure; yttrium refines grains, improves oxidation resistance and thermal stability, and improves high-temperature mechanical properties; silicon improves the casting fluidity and wear resistance of the alloy and participates in the formation of strengthening phases; manganese improves hardenability and strength, improves grain structure, and inhibits the formation of brittle phases; cobalt enhances high-temperature strength and improves the thermal stability and creep resistance of the alloy; chromium improves oxidation resistance and corrosion resistance, especially in high-temperature or acidic environments; and iron improves strength within a certain range.

[0013] Furthermore, the soluble counterweight head includes a soluble outer shell, the interior of which is filled with soluble salt.

[0014] The beneficial effects of adopting the above-mentioned further solution are: by utilizing the buoyancy of the soluble shell and the dissolving properties of the soluble salts, the function of guiding the plugging ball to move in a specific direction can be achieved, and no additional impact on the pipeline will be caused after dissolution.

[0015] Furthermore, the inner skeleton layer comprises a mixed woven mesh of NiTi alloy helices and carbon fibers.

[0016] The beneficial effects of adopting the above-mentioned further scheme are: the compression ratio of the NiTi alloy spiral and the carbon fiber mixed woven mesh is 5:1, the rebound rate is ≥95%, it can adapt to pipe diameter deformation, and ensure that the plugging ball can still maintain a stable structure when the pressure inside the pipe changes.

[0017] Furthermore, the inner skeleton layer comprises a composite woven mesh of shape memory polymer and high-strength fiber.

[0018] The beneficial effects of adopting the above-mentioned further solutions are that shape memory polymers can undergo shape changes under specific conditions to adapt to pipe diameter deformation, and their combination with high-strength fibers can enhance structural stability. For example, by combining shape memory polyurethane with aramid fibers and optimizing the composite process, it can achieve both adaptive deformation and good mechanical properties.

[0019] Furthermore, the mass percentage of the combined components of the intermediate expansion and dissolution layer is as follows: SAP microspheres 20%-30%, nitrile rubber 15%-25%, polyvinyl alcohol (PVA) 10%-20%, crosslinking agent (such as N,N-methylenebisacrylamide) 1%-3%, initiator (such as ammonium persulfate) 0.5%-1.5%, plasticizer (such as glycerin) 5%-10%, filler (such as calcium carbonate or barium sulfate) 10%-20%, and thermosensitive material (such as sodium polyacrylate) 5%-10%.

[0020] The beneficial effects of adopting the above-mentioned further solution are as follows: SAP microspheres (particle size 50-200μm) are dispersed in a nitrile rubber matrix to form an intermediate expansion and dissolution layer with an expansion rate ≥300% and a response time ≤30s. When it encounters fluid in the pipeline, it can expand rapidly to form a seal, providing time for pipeline repair. After expanding for a period of time, it can gradually dissolve in the liquid without causing secondary pollution, and it does not require manual or mechanical means to remove it from the pipeline.

[0021] Furthermore, the mass percentage of the combined components of the outer dissolving layer is as follows: 30%-40% polyvinyl alcohol (PVA), 20%-30% starch-based copolymer, 5%-10% plasticizer (such as glycerin), 2%-5% crosslinking agent (such as citric acid), 10%-20% filler (such as calcium carbonate), and 5%-10% water-soluble additive (such as polyethylene glycol).

[0022] The beneficial effect of adopting the above-mentioned further scheme is that, composed of PVA and starch-based copolymer, by controlling the degree of crosslinking to 2-30%, its dissolution pH range is 5-9, and it can be completely dissolved within 72 hours.

[0023] Furthermore, the outer dissolution layer also includes a fluorescent tracer in its composition.

[0024] The advantage of adopting the above-mentioned further solution is that it facilitates the detection of the dissolution status of the outer dissolution layer in subsequent processes.

[0025] This invention also provides a method for emergency repair of non-metallic composite pipes under pressure, which solves the above-mentioned technical problems by using a dissolvable and expandable plugging ball for emergency repair of non-metallic composite pipes under pressure, as described above, and includes the following steps: Step 1: Accurately locate the pipeline leak point using relevant detection equipment; Step 2: Use a high-pressure pneumatic launching device to inject the plugging ball into the pipeline. Under the pressure of the fluid inside the pipeline, the plugging ball reaches the leak location. Step 3: The plugging ball expands and forms a sealing layer upon contact with water or oil; Step four: After the plugging ball forms an effective seal, maintenance personnel perform maintenance operations on the leaking section of the pipeline; Step 5: After the pipeline repair is completed, the plug gradually dissolves, and the dissolved residue is discharged with the medium in the pipeline, thus completing the pipeline repair.

[0026] The beneficial effects of adopting the above solution are: after the plugging ball is placed in the water pipe or oil pipe, it can quickly expand and seal the pipe, avoiding the need to stop the flow and release pressure, greatly shortening the pipe maintenance time and reducing production interruption losses caused by pipe maintenance; and after the pipe maintenance is completed, it can dissolve on its own, avoiding secondary cleaning and not causing pollution to the fluid in the pipe. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is the process of the present invention; The attached diagram lists the components represented by each number as follows: 1. Soluble counterweight head; 2. Inner skeleton layer; 3. Intermediate expansion and dissolution layer; 4. Outer dissolution layer. Detailed Implementation

[0028] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0029] The present invention provides a soluble expansion plugging ball for emergency repair of non-metallic composite pipes under pressure, comprising a soluble counterweight head 1; Inner skeleton layer 2, which wraps around the outside of the soluble counterweight head 1, is used to expand outward for support after the external pressure decreases. An intermediate expansion and dissolution layer 3 is provided on the outside of the inner skeleton layer 2 to wrap the inner skeleton layer 2. The intermediate expansion and dissolution layer 3 expands upon contact with liquid and gradually dissolves after expansion. An outer dissolving layer 4 is disposed outside the intermediate expanding dissolving layer 3 to wrap the intermediate expanding dissolving layer 3. The outer dissolving layer 4 gradually dissolves upon contact with liquid.

[0030] In an embodiment of the present invention, the soluble counterweight 1 is a magnesium-aluminum alloy, and the mass percentage of the components of the magnesium-aluminum alloy is: magnesium 80%-88%, zinc 4%-7%, and regulating elements 5%-13%. The magnesium-zinc alloy is a soluble alloy used in pipeline repair as a sealing tool to guide the plugging ball to move directionally within the pipeline, enabling it to accurately reach the leak point. After completing its task, it dissolves rapidly in a specific liquid environment, avoiding secondary recycling.

[0031] The regulating element is one or more of aluminum, copper, nickel, yttrium, silicon, manganese, cobalt, chromium, and iron.

[0032] Aluminum, copper, nickel, yttrium, silicon, manganese, cobalt, chromium, and iron are used as control elements in magnesium-zinc alloys, each playing a different role. Different control elements can be selected based on actual needs. Specifically: Aluminum improves the strength and hardness of alloys, enhances casting performance, and strengthens corrosion resistance; Copper significantly improves the strength and heat resistance of alloys and promotes the precipitation of age-hardening phases; Nickel improves the corrosion resistance of alloys, enhances high-temperature performance, and stabilizes the alloy microstructure. Yttrium refines grain size, improves oxidation resistance and thermal stability, and enhances high-temperature mechanical properties. Silicon improves the casting fluidity and wear resistance of alloys and participates in the formation of strengthening phases; manganese improves hardenability and strength, improves grain structure, and inhibits the formation of brittle phases. Cobalt enhances high-temperature strength and improves the thermal stability and creep resistance of alloys; Chromium enhances antioxidant and corrosion resistance, especially in high-temperature or acidic environments; Iron, its strength can be increased within a certain range.

[0033] In another embodiment of the invention, the soluble counterweight head 1 includes a soluble outer shell, the interior of which is filled with soluble salt. Utilizing the buoyancy of the soluble outer shell and the dissolving properties of the soluble salt, the function of guiding the plugging ball to move in a specific direction is achieved, without causing any additional impact on the pipeline after dissolution.

[0034] The inner skeleton layer 2 includes a mixed woven mesh of NiTi alloy spirals and carbon fibers. The compression ratio of the mixed woven mesh of NiTi alloy spirals and carbon fibers is 5:1, and the resilience rate is ≥95%. It can adapt to pipe diameter deformation and ensure that the plugging ball can maintain a stable structure when the pressure inside the pipe changes.

[0035] Alternatively, the inner skeleton layer 2 may comprise a composite woven mesh of shape memory polymer and high-strength fiber. The shape memory polymer can change shape under specific conditions to adapt to pipe diameter deformation, and its combination with high-strength fiber enhances structural stability. For example, combining shape memory polyurethane with aramid fiber, through optimized composite processes, allows it to achieve both adaptive deformation and good mechanical properties.

[0036] In an embodiment of the present invention, the mass percentage of the combined components of the intermediate expansion and dissolution layer 3 is as follows: SAP microspheres 20%-30%, nitrile rubber 15%-25%, polyvinyl alcohol (PVA) 10%-20%, crosslinking agent (such as N,N-methylenebisacrylamide) 1%-3%, initiator (such as ammonium persulfate) 0.5%-1.5%, plasticizer (such as glycerin) 5%-10%, filler (such as calcium carbonate or barium sulfate) 10%-20%, and thermosensitive material (such as sodium polyacrylate) 5%-10%.

[0037] SAP microspheres: Highly absorbent resin microspheres with rapid water absorption and expansion properties, capable of forming a dense sealing layer in a short time.

[0038] Nitrile rubber: provides good mechanical properties and elasticity, ensuring that the expanded layer maintains structural integrity during expansion.

[0039] Polyvinyl alcohol (PVA): A temperature-sensitive material that can gradually dissolve at room temperature, allowing the expansion layer to degrade naturally after completing its sealing task.

[0040] Crosslinking agents (such as N,N-methylenebisacrylamide) and initiators (such as ammonium persulfate) are used to form a stable three-dimensional network structure and control the expansion rate and strength.

[0041] Plasticizers (such as glycerin): improve the flexibility and processing properties of materials.

[0042] Fillers (such as calcium carbonate or barium sulfate): adjust the density and cost of the material, while providing some mechanical support.

[0043] Temperature-sensitive materials (such as sodium polyacrylate): such as sodium polyacrylate, further enhance the temperature sensitivity of the expansion layer, so that it can gradually dissolve at room temperature.

[0044] The intermediate swelling and dissolving layer 3 is formed by dispersing SAP microspheres (particle size 50-200μm) in a nitrile rubber matrix. It has the characteristics of swelling rate ≥300% and response time ≤30s. When it encounters fluid in the pipeline, it can expand rapidly to form a seal, providing time for pipeline repair. After swelling for a period of time, it can gradually dissolve in the liquid without causing secondary pollution, and it does not need to be removed from the pipeline manually or by mechanical means.

[0045] The outer dissolving layer 4 has the following composition by mass percentage: 30%-40% polyvinyl alcohol (PVA), 20%-30% starch-based copolymer, 5%-10% plasticizer (such as glycerin), 2%-5% crosslinking agent (such as citric acid), 10%-20% filler (such as calcium carbonate), and 5%-10% water-soluble additive (such as polyethylene glycol).

[0046] Polyvinyl alcohol (PVA): It has good water solubility and biodegradability, and can gradually dissolve at room temperature.

[0047] Starch-based copolymers: These are produced by graft copolymerization of starch and vinyl monomers. They have good water solubility and biodegradability and can enhance the mechanical properties of the solubility layer.

[0048] Plasticizers (such as glycerin): increase the flexibility and processing properties of the solution layer.

[0049] Crosslinking agents (such as citric acid): used to form a stable network structure and improve the mechanical strength of the dissolved layer.

[0050] Fillers (such as calcium carbonate): adjust the density and cost of the dissolved layer, while providing some mechanical support.

[0051] Water-soluble additives (such as polyethylene glycol): further improve the water solubility of the solution layer, ensuring that it can dissolve quickly at room temperature.

[0052] Composed of PVA and starch-based copolymer, by controlling the degree of crosslinking to 2-30%, its dissolution pH range is 5-9, and it can be completely dissolved within 72 hours.

[0053] The outer dissolution layer 4 also includes a fluorescent tracer in its composition, which facilitates the detection of the dissolution status of the outer dissolution layer 4 in subsequent processes.

[0054] This invention also discloses a method for emergency repair of non-metallic composite pipes under pressure, which uses a dissolvable and expandable plugging ball for emergency repair of non-metallic composite pipes as described above, and includes the following steps: S1, using relevant detection equipment (such as pipeline inspection robots) to accurately locate pipeline leaks; S2, a high-pressure pneumatic launching device is used to inject the plugging ball into the pipeline. Under the pressure of the fluid in the pipeline, the plugging ball reaches the leak location. S3, the plugging ball expands upon contact with water or oil to form a sealing layer. Specifically, the medium inside the pipeline permeates through the micropores of the outer dissolution layer 4 into the intermediate expansion dissolution layer 3. The SAP in the intermediate expansion dissolution layer 3 rapidly absorbs water or oil upon contact with the fluid, while the inner skeleton layer 2 adapts to the deformation of the pipe diameter to ensure that the plugging ball fits tightly against the inner wall of the pipeline. After the plugging ball expands, it forms a sealing layer with a sealing pressure that can reach 1.5 times the working pressure of the pipeline (up to 10MPa), effectively preventing the leakage of the medium inside the pipeline. S4. After the plugging ball forms an effective seal, the maintenance personnel will carry out maintenance operations on the leaking section of the pipeline. S5, after the pipeline repair is completed, the plug gradually dissolves, and the dissolved residue is discharged with the medium in the pipeline, thus completing the pipeline repair.

[0055] The present invention has the following technical effects: greatly improved maintenance efficiency: traditional technology requires stopping the flow and depressurizing, and the whole maintenance process is time-consuming. However, the present invention can be operated under pressure and the sealing can be completed within 15 minutes, which greatly shortens the maintenance time and reduces the production interruption losses caused by pipeline maintenance.

[0056] Significant cost control: Traditional maintenance methods result in substantial economic losses due to service outages, coupled with high labor costs, leading to persistently high maintenance costs per operation. This invention eliminates the need for service outages, reducing maintenance costs by 70%, demonstrating a significant cost advantage.

[0057] Wider applicability: The soluble expansion plugging ball of the present invention can be adapted to non-metallic pipes of various materials, greatly expanding its application range.

[0058] Superior environmental performance: Traditional plugging balls require secondary cleaning and are prone to residue and pollution. The plugging ball of this invention can automatically dissolve, and the dissolved residue meets the GB / T17219 drinking water safety standard, causing no pollution to the environment and meeting environmental protection requirements.

[0059] Example 1 In this embodiment, the soluble counterweight 1 is a magnesium-aluminum alloy, and the mass percentage of the components of the magnesium-aluminum alloy is: magnesium 80%, zinc 7%, aluminum 4%, copper 3%, and nickel 6%.

[0060] The inner skeleton layer 2 comprises a mixed woven mesh of NiTi alloy spirals and carbon fibers; The mass percentage of the combined components of the intermediate expansion and dissolution layer 3 is as follows: SAP microspheres 20%, nitrile rubber 25%, polyvinyl alcohol (PVA) 20%, N,N-methylenebisacrylamide 3%, ammonium persulfate 1%, glycerol 6%, calcium carbonate or barium sulfate 20%, and sodium polyacrylate 5%.

[0061] The outer dissolving layer 4 has the following composition by mass percentage: 30% polyvinyl alcohol (PVA), 30% starch-based copolymer, 5% glycerol, 5% citric acid, 20% calcium carbonate, 9.5% polyethylene glycol, and 0.5% fluorescent agent.

[0062] Example 2 In this embodiment, the soluble counterweight 1 is a magnesium-aluminum alloy, and the mass percentage of the components of the magnesium-aluminum alloy is: magnesium 88%, zinc 4%, aluminum 2%, copper 2%, and nickel 2%.

[0063] The inner skeleton layer 2 comprises a mixed woven mesh of NiTi alloy spirals and carbon fibers; The mass percentage of the combined components of the intermediate expansion and dissolution layer 3 is as follows: SAP microspheres 30%, nitrile rubber 15%, polyvinyl alcohol (PVA) 15%, N,N-methylenebisacrylamide 3%, ammonium persulfate 1%, glycerol 6%, calcium carbonate or barium sulfate 20%, and sodium polyacrylate 10%.

[0064] The outer dissolving layer 4 has the following composition by mass percentage: 40% polyvinyl alcohol (PVA), 20% starch-based copolymer, 10% glycerol, 5% citric acid, 14.5% calcium carbonate, 10% polyethylene glycol, and 0.5% fluorescent agent.

[0065] Example 3 In this embodiment, the soluble counterweight 1 is a magnesium-aluminum alloy, and the mass percentage of the components of the magnesium-aluminum alloy is: magnesium 85%, zinc 5%, aluminum 3%, copper 2%, and nickel 5%.

[0066] The inner skeleton layer 2 comprises a mixed woven mesh of NiTi alloy spirals and carbon fibers; The mass percentage of the combined components of the intermediate expansion and dissolution layer 3 is as follows: SAP microspheres 25%, nitrile rubber 20%, polyvinyl alcohol (PVA) 18%, N,N-methylenebisacrylamide 2%, ammonium persulfate 1.5%, glycerol 8.5%, calcium carbonate or barium sulfate 17%, and sodium polyacrylate 8%.

[0067] The outer dissolving layer 4 has the following composition by mass percentage: 35% polyvinyl alcohol (PVA), 25% starch-based copolymer, 10% glycerol, 4.5% citric acid, 15% calcium carbonate, 10% polyethylene glycol, and 0.5% fluorescent agent.

[0068] Example 4 In this embodiment, the soluble counterweight 1 is a magnesium-aluminum alloy, and the mass percentage of the components of the magnesium-aluminum alloy is: magnesium 82%, zinc 6%, aluminum 3%, copper 3%, and nickel 6%.

[0069] The inner skeleton layer 2 comprises a mixed woven mesh of NiTi alloy spirals and carbon fibers; The mass percentages of the combined components of the intermediate expansion and dissolution layer 3 are as follows: SAP microspheres 28%, nitrile rubber 22%, polyvinyl alcohol (PVA) 16%, N,N-methylenebisacrylamide 2%, ammonium persulfate 1%, glycerol 6%, calcium carbonate or barium sulfate 16%, and sodium polyacrylate 9%.

[0070] The outer dissolving layer 4 has the following composition by mass percentage: polyvinyl alcohol (PVA) 38%, starch-based copolymer 22%, glycerol 7.5%, citric acid 2%, calcium carbonate 20%, polyethylene glycol 10%, and fluorescent agent 0.5%.

[0071] Example 5 In this embodiment, the soluble counterweight 1 is a magnesium-aluminum alloy, and the mass percentage of the components of the magnesium-aluminum alloy is: magnesium 84%, zinc 6%, aluminum 3%, copper 3%, and nickel 4%.

[0072] The inner skeleton layer 2 comprises a mixed woven mesh of NiTi alloy spirals and carbon fibers; The mass percentage of the combined components of the intermediate expansion and dissolution layer 3 is as follows: SAP microspheres 26%, nitrile rubber 24%, polyvinyl alcohol (PVA) 18%, N,N-methylenebisacrylamide 1.5%, ammonium persulfate 1.5%, such as glycerol 6%, calcium carbonate or barium sulfate 19%, and sodium polyacrylate 9%.

[0073] The outer dissolving layer 4 has the following composition by mass percentage: polyvinyl alcohol (PVA) 34%, starch-based copolymer 27.5%, glycerol 8%, citric acid 3%, calcium carbonate 18%, polyethylene glycol 9%, and fluorescent agent 0.5%.

[0074] Example 6 In this embodiment, the soluble counterweight 1 is a magnesium-aluminum alloy, and the mass percentage of the components of the magnesium-aluminum alloy is: magnesium 83%, zinc 7%, aluminum 3%, copper 3%, and nickel 4%.

[0075] The inner skeleton layer 2 comprises a mixed woven mesh of NiTi alloy spirals and carbon fibers; The mass percentage of the combined components of the intermediate expansion and dissolution layer 3 is as follows: SAP microspheres 27%, nitrile rubber 23%, polyvinyl alcohol (PVA) 17%, N,N-methylenebisacrylamide 1.5%, ammonium persulfate 1.5%, such as glycerol 8%, calcium carbonate or barium sulfate 8%, and sodium polyacrylate 10%.

[0076] The outer dissolving layer 4 has the following composition by mass percentage: polyvinyl alcohol (PVA) 32.5%, starch-based copolymer 29%, glycerol 7%, citric acid 4%, calcium carbonate 18%, polyethylene glycol 9%, and fluorescent agent 0.5%.

[0077] The following is an experiment on the expansion and dissolution time of intermediate expansion and dissolution layers 3 with different component proportions in an oil environment at 20 degrees Celsius. The experimental results are as follows: Table 1. Composition of the intermediate expansion layer in different embodiments of the experiment. Table 2. Expansion time and dissolution time of the intermediate expansion layer for the different experimental components mentioned above. The above experiments show that the expansion time can be controlled by changing the weight ratio of the initiator and the plasticizer, and the dissolution time of the entire expansion layer can be controlled by changing the weight ratio of polyvinyl alcohol and the temperature-sensitive material.

[0078] In the description of this invention, it should be understood that the terms "center," "length," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "inner," "outer," "circumferential," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the system 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.

[0079] In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0080] 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 part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0081] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. 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 dissolvable and expandable plugging ball for emergency repair of non-metallic composite pipes under pressure, characterized in that, Including soluble counterweights; An inner skeleton layer, which wraps around the outside of the soluble counterweight head, is used to expand outward for support after the external pressure decreases. An intermediate expansion and dissolution layer is provided on the outside of the inner skeleton layer to wrap the inner skeleton layer. The intermediate expansion and dissolution layer expands upon contact with liquid and gradually dissolves after expansion. An outer dissolving layer is provided outside the intermediate expanding dissolving layer to wrap around it. The outer dissolving layer gradually dissolves upon contact with a liquid.

2. The dissolvable expansion plugging ball for live repair of non-metallic composite pipes according to claim 1, characterized in that, The soluble counterweight is a magnesium-aluminum alloy, and the mass percentage of the components of the magnesium-aluminum alloy is: magnesium 80%-88%, zinc 4%-7%, and control elements 5%-13%.

3. The dissolvable expansion plugging ball for live repair of non-metallic composite pipes according to claim 2, characterized in that, The regulating element is one or more of aluminum, copper, nickel, yttrium, silicon, manganese, cobalt, chromium, and iron.

4. The dissolvable expansion plugging ball for live repair of non-metallic composite pipes according to claim 1, characterized in that, The soluble counterweight head includes a soluble outer shell, the interior of which is filled with soluble salt.

5. The dissolvable expansion plugging ball for live repair of non-metallic composite pipes according to claim 1, characterized in that, The inner skeleton layer comprises a mixed woven mesh of NiTi alloy spirals and carbon fibers.

6. The dissolvable expansion plugging ball for live repair of non-metallic composite pipes according to claim 1, characterized in that, The inner skeleton layer comprises a composite woven mesh of shape memory polymer and high-strength fiber.

7. The dissolvable expansion plugging ball for live repair of non-metallic composite pipes according to claim 1, characterized in that, The mass percentage of the combined components of the intermediate expansion and dissolution layer is as follows: SAP microspheres 20%-30%, nitrile rubber 15%-25%, polyvinyl alcohol 10%-20%, crosslinking agent 1%-3%, initiator 0.5%-1.5%, plasticizer 5%-10%, filler 10%-20%, and thermosensitive material 5%-10%.

8. The dissolvable expansion plugging ball for live repair of non-metallic composite pipes according to claim 1, characterized in that, The mass percentage of the combined components of the outer dissolving layer is as follows: 30%-40% polyvinyl alcohol, 20%-30% starch-based copolymer, 5%-10% plasticizer, 2%-5% crosslinking agent, 10%-20% filler, and 5%-10% water-soluble additives.

9. A dissolvable expansion plugging ball for live repair of non-metallic composite pipes according to claim 8, characterized in that, The outer dissolution layer also includes a fluorescent tracer in its composition.

10. A method for emergency repair of non-metallic composite pipes under pressure, characterized in that, The following steps are included in the live repair of non-metallic composite pipes using the dissolvable expansion plugging ball described in any one of items 1 to 8 above: Step 1: Accurately locate the pipeline leak point using relevant detection equipment; Step 2: Use a high-pressure pneumatic launching device to inject the plugging ball into the pipeline. Under the pressure of the fluid inside the pipeline, the plugging ball reaches the leak location. Step 3: The plugging ball expands upon contact with water or oil and forms a sealing layer at the leak location; Step four: After the plugging ball forms an effective seal, maintenance personnel perform maintenance operations on the leaking section of the pipeline; Step 5: After the pipeline repair is completed, the plug gradually dissolves, and the dissolved residue is discharged with the medium in the pipeline, thus completing the pipeline repair.

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