A method for repairing damage of a multi-way oil pipe

Abstract

The present invention relates to the technical field of transportation pipelines, and particularly relates to a method for repairing damages of a multi-way oil pipe. An optical fiber sensor, a resistance wire, a first microcapsule, and a second microcapsule are fixed at the pipe connection or branch of the multi-way oil pipe. When the optical fiber sensor detects damages at the pipe connection or branch of the multi-way oil pipe, the resistance wire is electrified to generate heat, causing the first microcapsule to rupture and release a second liquid resin, and at the same time causing the second microcapsule to rupture and release a second curing agent. The second liquid resin reacts with the second curing agent to complete the second curing reaction, thus completing the repair. The multi-way oil pipe is prepared from a first liquid resin, a first curing agent, and a multi-way oil pipe preform. The temperature of the resistance wire after heating is lower than the glass transition temperatures of the first liquid resin and the second liquid resin. The present invention realizes the instant and automatic repair of the multi-way oil pipe, and the method is simple, which is applicable to scenarios with high requirements for pipeline sealing performance in industries such as oil exploitation and chemical transportation.

Description

Technical Field

[0001] The present invention relates to the technical field of conveying pipelines, and particularly relates to a method for repairing damages of a multi-way oil pipe. Background Art

[0002] With the continuous growth of energy demand, the extraction and transportation technologies of oil, natural gas and chemical products face higher requirements for pipeline performance. However, for multi-way oil pipes, there are many problems in traditional designs. For example, the splicing and forming process used not only has a complex process, but also results in weak joints, poor sealing performance and insufficient durability, making it difficult to cope with complex high-temperature, high-pressure and corrosive environments. Any minor damage may trigger more serious safety accidents such as rupture and leakage, increasing potential safety hazards. Therefore, the immediate damage repair of multi-way oil pipes is of great significance.

[0003] In the prior art, most repair methods rely on manual repair and external reinforcement, with limited restoration effect on the pressure-bearing capacity of pipelines, and the repair process cannot achieve immediate response.

[0004] Although fiber Bragg grating (FBG) sensors have been used in the health monitoring of composite structures in the prior art. For example, a patent application with the publication number CN102564332A discloses a method for embedding FBG sensors into three-dimensional braided composite parts to monitor the strain and damage inside the material. However, the technical solution of this patent application only monitors the damage inside the material and does not disclose how to perform damage repair. If manual repair methods are used, the ideal repair effect still cannot be achieved, and due to the time lag of manual repair response, it is impossible to immediately repair the damage.

[0005] Therefore, it is necessary to research a method for repairing damages of multi-way oil pipes with immediate and automated repair. Summary of the Invention

[0006] The object of the present invention is to solve the above problems existing in the prior art and provide a method for repairing damages of a multi-way oil pipe.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A method for repairing damages of a multi-way oil pipe (i.e., an oil pipe with three or more connection ports), fixing an optical fiber sensor, a resistance wire, a first microcapsule and a second microcapsule at the pipe connection or branch of the multi-way oil pipe. When the optical fiber sensor detects damage at the pipe connection or branch of the multi-way oil pipe, power is supplied to the resistance wire to make the resistance wire heat up, causing the first microcapsule to rupture and release a second liquid resin, and at the same time causing the second microcapsule to rupture and release a second curing agent. The second liquid resin and the second curing agent undergo a second curing reaction, thus completing the repair.

[0009] The multi - way oil pipe is obtained from a first liquid resin, a first curing agent, and a multi - way oil pipe preform;

[0010] After the resistance wire generates heat, the temperature is lower than the glass transition temperatures of the first liquid resin and the second liquid resin, preventing the resin from softening or flowing out prematurely and affecting the repair effect.

[0011] As a preferred technical solution:

[0012] For a method for repairing damage to a multi - way oil pipe as described above, the fiber optic sensor is an optical fiber with multiple Bragg gratings engraved on its surface, which can respond and send a trigger signal within 1 - 2 seconds after damage occurs.

[0013] For a method for repairing damage to a multi - way oil pipe as described above, the number of fiber optic sensors is multiple and arranged in parallel, and the distance between two adjacent fiber optic sensors is 2 - 4 mm. For example, the number of fiber optic sensors is 3 - 6;

[0014] For a method for repairing damage to a multi - way oil pipe as described above, the duration of energizing the resistance wire ≤ 40 s; the temperature after the resistance wire generates heat reaches 85 - 89 °C; the wall materials of the first microcapsule and the second microcapsule are one of polyurethane and polystyrene; the second liquid resin is one of unsaturated polyester resin, epoxy resin, polyurethane resin, and bismaleimide resin, and the second curing agent is one of acid anhydride, peroxide initiator, dicyandiamide, imidazole, and polyetheramine. The second liquid resin and the second curing agent can undergo a second curing reaction at 20 - 60 °C, and can quickly restore the sealing performance and strength at the connection or branch of the oil pipe.

[0015] For a method for repairing damage to a multi - way oil pipe as described above, the mass ratio of the second liquid resin to the second curing agent is 100:1.5 - 90.

[0016] For a method for repairing damage to a multi - way oil pipe as described above, the preparation process of the multi - way oil pipe is: after injecting the mixture of the first liquid resin and the first curing agent into the multi - way oil pipe preform, a first curing reaction is carried out to obtain the multi - way oil pipe. Among them, the multi - way oil pipe preform is woven from yarns. In this way, a seamless integral - formed structure can be obtained through the weaving process, which is beneficial to improving the connection strength and sealing performance at the branch of the multi - way oil pipe.

[0017] For a method for repairing damage to a multi - way oil pipe as described above, the implementation method of fixing the fiber optic sensor at the connection or branch of the multi - way oil pipe is: during the process of weaving the multi - way oil pipe preform, when weaving the connection or branch of the multi - way oil pipe preform, the fiber optic sensor and the yarn are combined and woven together, so as to ensure that the fiber optic sensor is stably and reliably fixed at the connection or branch of the multi - way oil pipe.

[0018] For a method of repairing damage to a multi-way oil pipe as described above, the implementation of fixing the resistance wire at the pipe connection or branch of the multi-way oil pipe is as follows: During the process of braiding the preform of the multi-way oil pipe, when braiding the pipe connection or branch of the preform of the multi-way oil pipe, the resistance wire and the yarn are combined and braided together, so as to ensure that the resistance wire is stably and reliably fixed at the pipe connection or branch of the multi-way oil pipe.

[0019] For a method of repairing damage to a multi-way oil pipe as described above, the implementation of fixing the first microcapsule and the second microcapsule at the pipe connection or branch of the multi-way oil pipe is as follows: During the process of braiding the preform of the multi-way oil pipe, when braiding the pipe connection or branch of the preform of the multi-way oil pipe, the first microcapsule and the second microcapsule are incorporated into the central position of the preform of the multi-way oil pipe by using the round tube braiding process.

[0020] For a method of repairing damage to a multi-way oil pipe as described above, the axial tensile strength of the repaired multi-way oil pipe is 91-95% of the axial tensile strength of the multi-way oil pipe before damage. The repaired multi-way oil pipe does not leak during the sealing test and can maintain good performance in the actual working environment.

[0021] Beneficial effects:

[0022] (1) In the present invention, the optical fiber sensor, the resistance wire, the first microcapsule and the second microcapsule are fixed at the pipe connection or branch of the multi-way oil pipe. When the optical fiber sensor detects damage, the system automatically triggers the resistance wire to heat up, causing the first microcapsule to rupture and release the second liquid resin, and at the same time causing the second microcapsule to rupture and release the second curing agent. The second liquid resin reacts with the second curing agent to repair the damage at the pipe connection or branch. It not only realizes the instant and rapid detection of damage to the multi-way oil pipe, but also can immediately start the repair process automatically after detecting the damage, quickly restore the pipe sealing performance, without shutdown or manual intervention, realizing instant and automatic repair of damage, and significantly improving the repair efficiency.

[0023] (2) The method for repairing damage to the multi-way oil pipe of the present invention is easy to operate, reduces the maintenance cost, and is applicable to scenarios with high requirements for pipe sealing performance in industries such as oil extraction and chemical transportation. Description of the drawings

[0024] Figure 1 is a schematic structural diagram of the multi-way oil pipe adopted by the present invention;

[0025] Among them, 1 is the optical fiber sensor, 2 is the resistance wire, 3 is the first microcapsule, 4 is the second microcapsule, and 5 is the pipe body. Detailed implementation manners

[0026] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0027] The following are the test methods for relevant performance indicators in each embodiment:

[0028] (1) Axial tensile strength: Tested in accordance with GB / T 5349-2005 "Test Method for Axial Tensile Properties of Fiber Reinforced Thermosetting Plastic Pipes".

[0029] (2) Sealing performance: The specific detection method is as follows:

[0030] First, use a MAXIMATOR G350 (maximum pressure 350 MPa) high-pressure pump to stepwise increase the pressure in the inner cavity of the specimen with air as the medium. The pressure increase amplitude each time is 10% PN and the pressure is maintained for 10 min. After reaching 3×PN, the pressure is maintained for 8 h;

[0031] Then, use a LACO Technologies MS68-2 leak test system to detect leaks;

[0032] Finally, judge whether the leakage rate < 1×10 -2 mg / (m·s) holds. If so, it is regarded as no leakage; otherwise, it is regarded as leakage.

[0033] Example 1

[0034] A method for repairing damage to a multi-pass oil pipe, the specific steps are as follows:

[0035] (1) Prepare raw materials;

[0036] Optical fiber sensor: An optical fiber with eight Bragg gratings engraved on its surface, and the number of optical fiber sensors is 3;

[0037] Resistance wire: Manufactured by ESAB of Sweden, model OK Autrod 16.12 (Ni80Cr20 alloy, diameter 0.3 mm);

[0038] First liquid resin: Bisphenol A epoxy resin, manufactured by Baling Petrochemical Co., Ltd., grade CYD-128, glass transition temperature 120 °C;

[0039] First curing agent: Modified aliphatic amine, manufactured by Evonik, grade Ancamine® 2441;

[0040] The first microcapsule: The wall material is polyurethane, manufactured by Jiangsu Zhongke Polymer New Materials Industry Technology Research Institute Co., Ltd., with the grade of ETPU. The second liquid resin (bisphenol F epoxy resin, manufactured by Westlake Epoxy, with the grade of Epoxy Research Resin RSL 4515 and a glass transition temperature of 148°C) is encapsulated inside the first microcapsule;

[0041] The second microcapsule: The wall material is polyurethane, manufactured by Jiangsu Zhongke Polymer New Materials Industry Technology Research Institute Co., Ltd., with the grade of ETPU. The second curing agent (latent imidazole type, manufactured by Asahi Kasei Novacure with the grade of HX-3941HP) is encapsulated inside the second microcapsule. The mass ratio of the second liquid resin to the second curing agent is 100:8;

[0042] Yarn: 12k carbon fiber, manufactured by Toray, with the model of T700;

[0043] (2) Weave the multi-pass oil pipe preform;

[0044] Use the yarn to weave the multi-pass oil pipe preform, and this multi-pass oil pipe preform is a four-way oil pipe preform;

[0045] During the process of weaving the multi-pass oil pipe preform, when weaving the pipe connection or branch of the multi-pass oil pipe preform, combine the fiber optic sensor and the yarn together for weaving, and the fiber optic sensors are arranged in parallel. The distance between adjacent two fiber optic sensors is 2 mm, so as to fix the fiber optic sensor at the pipe connection or branch of the multi-pass oil pipe;

[0046] During the process of weaving the multi-pass oil pipe preform, when weaving the pipe connection or branch of the multi-pass oil pipe preform, combine the resistance wire and the yarn together for weaving, so as to fix the resistance wire at the pipe connection or branch of the multi-pass oil pipe;

[0047] During the process of weaving the multi-pass oil pipe preform, when weaving the pipe connection or branch of the multi-pass oil pipe preform, use the round tube weaving process to incorporate the first microcapsule and the second microcapsule into the central position of the multi-pass oil pipe preform, so as to fix the first microcapsule and the second microcapsule at the pipe connection or branch of the multi-pass oil pipe;

[0048] (3) Prepare the multi-pass oil pipe;

[0049] After injecting the mixture of the first liquid resin and the first curing agent into the multi-pass oil pipe preform, carry out the first curing reaction to obtain the multi-pass oil pipe. As Figure 1 shown, the multi-pass oil pipe is composed of a fiber optic sensor 1, a resistance wire 2, a first microcapsule 3, a second microcapsule 4 and a pipe body 5;

[0050] In the mixture of the first liquid resin and the first curing agent, the weight ratio of the first liquid resin to the first curing agent is 100:28;

[0051] (4) Detect and repair damage;

[0052] When the fiber optic sensor detects damage at the pipe connection or branch of the multi-way oil pipe, the resistance wire is energized to make it heat up. The duration of energizing the resistance wire is 30 s, and the temperature of the resistance wire reaches 89 °C after heating. The temperature of the resistance wire after heating is lower than the glass transition temperature of the first liquid resin and the second liquid resin, causing the first microcapsule to rupture and release the second liquid resin, and at the same time causing the second microcapsule to rupture and release the second curing agent. The second liquid resin and the second curing agent undergo a second curing reaction, thus completing the repair.

[0053] The axial tensile strength of the repaired multi-way oil pipe is 91% of that of the multi-way oil pipe before damage, and the repaired multi-way oil pipe does not leak in the sealing test.

[0054] Example 2

[0055] A method for repairing damage to a multi-way oil pipe, the specific steps are as follows:

[0056] (1) Prepare raw materials;

[0057] Fiber optic sensor: an optical fiber with ten Bragg gratings engraved on its surface, and the number of fiber optic sensors is 5;

[0058] Resistance wire: manufactured by Sandvik, model KANTHAL A-1 (FeCrAl alloy, diameter 0.25 mm);

[0059] First liquid resin: polyester polyol, manufactured by Covestro, grade Desmophen® 670BA, glass transition temperature 90 °C;

[0060] First curing agent: manufactured by Covestro, grade Desmodur® ultra E 30500, mixing ratio 100:33.

[0061] First microcapsule: the wall material is polystyrene, manufactured by Zhongke Leiming (Beijing) Technology Co., Ltd., grade PS080000, and the first microcapsule internally encapsulates the second liquid resin (unsaturated polyester resin, manufactured by INEOS gronp, grade Aropol™, glass transition temperature 100 °C);

[0062] Second microcapsule: The wall material is polyurethane, the manufacturer is Jiangsu Zhongke Polymer New Materials Industry Technology Research Institute Co., Ltd., the grade is ETPU, the second microcapsule encapsulates a second curing agent (benzoyl peroxide, the manufacturer is AkzoNobel, the grade is AkzoNobel Perkadox CH-50) inside, and the mass ratio of the second liquid resin to the second curing agent is 100:1.8;

[0063] Yarn: 12k carbon fiber, the manufacturer is Hexcel, and the model is HexForce® 12K;

[0064] (2)Weave the preform of the multi-pass oil pipe;

[0065] Use the yarn to weave the preform of the multi-pass oil pipe, and the preform of the multi-pass oil pipe is the preform of the four-way oil pipe;

[0066] During the process of weaving the preform of the multi-pass oil pipe, when weaving the pipe connection or branch of the preform of the multi-pass oil pipe, combine the fiber optic sensor and the yarn together for weaving, and the fiber optic sensors are arranged in parallel, and the distance between adjacent two fiber optic sensors is 3mm, so as to fix the fiber optic sensor at the pipe connection or branch of the multi-pass oil pipe;

[0067] During the process of weaving the preform of the multi-pass oil pipe, when weaving the pipe connection or branch of the preform of the multi-pass oil pipe, combine the resistance wire and the yarn together for weaving, so as to fix the resistance wire at the pipe connection or branch of the multi-pass oil pipe;

[0068] During the process of weaving the preform of the multi-pass oil pipe, when weaving the pipe connection or branch of the preform of the multi-pass oil pipe, use the round pipe weaving process to incorporate the first microcapsule and the second microcapsule into the central position of the preform of the multi-pass oil pipe, so as to fix the first microcapsule and the second microcapsule at the pipe connection or branch of the multi-pass oil pipe;

[0069] (3)Prepare the multi-pass oil pipe;

[0070] After injecting the mixture of the first liquid resin and the first curing agent into the preform of the multi-pass oil pipe, carry out the first curing reaction to obtain the multi-pass oil pipe. As Figure 1 shown, the multi-pass oil pipe is composed of a fiber optic sensor 1, a resistance wire 2, a first microcapsule 3, a second microcapsule 4 and a pipe body 5;

[0071] In the mixture of the first liquid resin and the first curing agent, the weight ratio of the first liquid resin to the first curing agent is 100:95;

[0072] (4)Detect and repair damage;

[0073] When the fiber optic sensor detects damage at the pipe connection or branch of the multi-way oil pipe, the resistance wire is energized, causing the resistance wire to heat up. The duration of energizing the resistance wire is 34 s. After the resistance wire heats up, the temperature reaches 85 °C, which is lower than the glass transition temperature of the first liquid resin and the second liquid resin, triggering the rupture of the first microcapsule to release the second liquid resin, and at the same time triggering the rupture of the second microcapsule to release the second curing agent. The second liquid resin and the second curing agent undergo a second curing reaction, thus completing the repair.

[0074] The axial tensile strength of the repaired multi-way oil pipe is 93% of that of the multi-way oil pipe before damage, and the repaired multi-way oil pipe does not leak during the sealing test.

[0075] Example 3

[0076] A method for repairing damage to a multi-way oil pipe, the specific steps are as follows:

[0077] (1) Prepare raw materials;

[0078] Fiber optic sensor: an optical fiber with twelve Bragg gratings engraved on its surface, and the number of fiber optic sensors is 6;

[0079] Resistance wire: manufactured by KOBELCO of Japan, model NCF 600 (NiCr alloy, diameter 0.2 mm);

[0080] First liquid resin: epoxy resin, manufactured by Changshu Juhe Chemical Co., Ltd., brand JC-02A, glass transition temperature 135 °C;

[0081] First curing agent: manufactured by Changshu Juhe Chemical Co., Ltd., brand JC-02B;

[0082] First microcapsule: the wall material is polyurethane, manufactured by Jiangsu Zhongke Polymer New Materials Industry Technology Research Institute Co., Ltd., brand ETPU, and the first microcapsule internally encapsulates the second liquid resin (low-temperature curing epoxy resin, manufactured by Huntsman, brand Huntsman Araldite LY 3585, glass transition temperature 128 °C);

[0083] Second microcapsule: the wall material is polyurethane, manufactured by Jiangsu Zhongke Polymer New Materials Industry Technology Research Institute Co., Ltd., brand ETPU, and the second microcapsule internally encapsulates the second curing agent (modified polyetheramine, manufactured by Huntsman, brand JEFFAMINE® D-230 Polyetheramine), and the mass ratio of the second liquid resin to the second curing agent is 100:8.5;

[0084] Yarn: 12k carbon fiber, manufactured by SGL Carbon, model SIGRAFIL® 12K;

[0085] (2)Weave the preform of the multi-pass oil pipe;

[0086] The preform of the multi-pass oil pipe is formed by weaving the yarn, and the preform of the multi-pass oil pipe is a preform of a four-way oil pipe;

[0087] During the process of weaving the preform of the multi-pass oil pipe, when weaving the pipe connection or branch of the preform of the multi-pass oil pipe, the fiber optic sensor and the yarn are combined and woven together, and the fiber optic sensors are arranged in parallel, and the distance between adjacent two fiber optic sensors is 4 mm, so as to fix the fiber optic sensor at the pipe connection or branch of the multi-pass oil pipe;

[0088] During the process of weaving the preform of the multi-pass oil pipe, when weaving the pipe connection or branch of the preform of the multi-pass oil pipe, the resistance wire and the yarn are combined and woven together, so as to fix the resistance wire at the pipe connection or branch of the multi-pass oil pipe;

[0089] During the process of weaving the preform of the multi-pass oil pipe, when weaving the pipe connection or branch of the preform of the multi-pass oil pipe, the first microcapsule and the second microcapsule are woven into the central position of the preform of the multi-pass oil pipe by using the round pipe weaving process, so as to fix the first microcapsule and the second microcapsule at the pipe connection or branch of the multi-pass oil pipe;

[0090] (3)Prepare the multi-pass oil pipe;

[0091] After injecting the mixture of the first liquid resin and the first curing agent into the preform of the multi-pass oil pipe, the first curing reaction is carried out to obtain the multi-pass oil pipe. As Figure 1 shown, the multi-pass oil pipe is composed of a fiber optic sensor 1, a resistance wire 2, a first microcapsule 3, a second microcapsule 4 and a pipe body 5;

[0092] In the mixture of the first liquid resin and the first curing agent, the weight ratio of the first liquid resin to the first curing agent is 100:85;

[0093] (4)Detect and repair damages;

[0094] When the fiber optic sensor monitors that there is damage at the pipe connection or branch of the multi-pass oil pipe, the resistance wire is electrified, so that the resistance wire generates heat. The duration of electrifying the resistance wire is 37 s, and the temperature of the resistance wire reaches 85 °C after heating. The temperature of the resistance wire after heating is lower than the glass transition temperature of the first liquid resin and the second liquid resin, which causes the first microcapsule to rupture and release the second liquid resin, and at the same time causes the second microcapsule to rupture and release the second curing agent. The second liquid resin and the second curing agent undergo the second curing reaction, and the repair is completed.

[0095] The axial tensile strength of the repaired multi-pass oil pipe is 95% of that of the multi-pass oil pipe before damage, and the repaired multi-pass oil pipe does not leak in the sealing test.

Claims

1. A method for repairing damage to a multi-way oil pipe, characterized in that, Fix the fiber optic sensor, resistance wire, first microcapsule and second microcapsule at the pipe connection or branch of the multi-way oil pipe. When the fiber optic sensor detects damage at the pipe connection or branch of the multi-way oil pipe, energize the resistance wire to make it heat up, causing the first microcapsule to rupture and release the second liquid resin, and at the same time causing the second microcapsule to rupture and release the second curing agent. The second liquid resin reacts with the second curing agent in a second curing reaction, thus completing the repair. The multi-way oil pipe is made from the first liquid resin, the first curing agent and the multi-way oil pipe preform. The preparation process of the multi-way oil pipe is as follows: after injecting the mixture of the first liquid resin and the first curing agent into the multi-way oil pipe preform, conduct the first curing reaction to obtain the multi-way oil pipe, where the multi-way oil pipe preform is woven from yarns. The temperature of the resistance wire after heating is lower than the glass transition temperatures of the first liquid resin and the second liquid resin. The method of fixing the fiber optic sensor at the pipe connection or branch of the multi-way oil pipe is as follows: during the process of weaving the multi-way oil pipe preform, when weaving the pipe connection or branch of the multi-way oil pipe preform, combine the fiber optic sensor and the yarn and weave them together. The method of fixing the resistance wire at the pipe connection or branch of the multi-way oil pipe is as follows: during the process of weaving the multi-way oil pipe preform, when weaving the pipe connection or branch of the multi-way oil pipe preform, combine the resistance wire and the yarn and weave them together. The method of fixing the first microcapsule and the second microcapsule at the pipe connection or branch of the multi-way oil pipe is as follows: during the process of weaving the multi-way oil pipe preform, when weaving the pipe connection or branch of the multi-way oil pipe preform, use the round pipe weaving process to incorporate the first microcapsule and the second microcapsule into the central position of the multi-way oil pipe preform.

2. The damage repair method of a multi-way oil pipe according to claim 1, characterized in that, The fiber optic sensor is an optical fiber with multiple Bragg gratings engraved on its surface.

3. A damage repair method for a multi-pass oil pipe according to claim 1, characterized in that, The number of fiber optic sensors is multiple and they are arranged in parallel. The distance between two adjacent fiber optic sensors is 2 - 4 mm.

4. A method for repairing damage to a multi-way oil pipe according to claim 1, characterized in that, The duration of energizing the resistance wire ≤ 40 s; the temperature of the resistance wire after heating reaches 85 - 89 °C; the wall materials of the first microcapsule and the second microcapsule are one of polyurethane and polystyrene; the second liquid resin is one of unsaturated polyester resin, epoxy resin, polyurethane resin and bismaleimide resin, and the second curing agent is one of acid anhydride, peroxide initiator, dicyandiamide, imidazoles and polyetheramine.

5. A method for repairing damage to a multi-pass oil pipe according to claim 4, characterized in that, The mass ratio of the second liquid resin to the second curing agent is 100:1.5 - 90.

6. A method for repairing damage to a multi-way oil pipe according to claim 1, characterized in that, The axial tensile strength of the repaired multi-way oil pipe is 91 - 95% of the axial tensile strength of the multi-way oil pipe before damage, and no leakage occurs in the repaired multi-way oil pipe during the sealing test.

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