In-service buried steel skeleton reinforced polyethylene oil and gas field sewage pipeline repairing structure

Abstract

The utility model discloses an in-service buried steel skeleton reinforced polyethylene oil and gas field sewage pipeline repairing structure which aims at solving the problem that in the prior art, a systematic repairing scheme is lacked according to the damaged situation of steel skeletons of different grades. The repairing structure is divided into a first-stage repairing scheme to a fourth-stage repairing scheme according to the damaged grade of the steel framework, and effective repairing of the damaged pipeline is achieved through the steps of high polymer material filling, glass fiber composite material reinforcing layer protection, viscoelastic body and polypropylene anti-corrosion layer recovery and the like. The first-level repairing scheme is mainly used for the situation that an outer anti-corrosion layer is damaged and a steel framework is not damaged. According to the second-level repairing scheme and the third-level repairing scheme, the number of composite material reinforcing layers is increased to two layers and six layers correspondingly, and steel skeleton damage of different degrees is dealt with; according to the four-stage repairing scheme, a thorough repairing measure of replacing a pipe and buckling a connector is adopted for the conditions of serious corrosion penetration and cracking. The pipeline anti-corrosion device has novelty, creativity and practicability, is easy and convenient to operate and controllable in cost, and can improve the overall strength and the anti-corrosion performance of the pipeline.

Description

Technical Field

[0001] The utility model relates to the technical field of oil and gas field sewage pipelines, specifically a repair structure for in-service buried steel skeleton reinforced polyethylene oil and gas field sewage pipelines, aiming to solve the problem of steel skeleton damage that occurs during long-term use of pipelines in oil and gas field environments, and to provide an economical, efficient and reliable repair solution. Background Art

[0002] Existing buried steel-reinforced polyethylene (PE) oil and gas field wastewater pipelines are widely used in oil and gas field wastewater treatment systems due to their excellent corrosion resistance, high strength, and good toughness. However, due to the complexity and corrosiveness of the oil and gas field environment, pipelines may experience varying degrees of steel frame damage during long-term operation, such as damage to the anti-corrosion coating, exposure of the steel frame, and cracks. Traditional repair methods, such as direct pipe replacement, are costly and difficult to implement, necessitating a more economical and efficient repair structure. Summary of the Invention

[0003] In response to the above problems, the utility model provides an in-service buried steel skeleton reinforced polyethylene oil and gas field sewage pipeline repair structure. The structure takes corresponding repair measures according to the different damage levels of the steel skeleton, ensuring the repair effect while reducing the repair cost.

[0004] The utility model adopts the following technical solutions:

[0005] This utility model relates to a repair structure for in-service, buried steel-framed reinforced polyethylene (PE) oil and gas field sewage pipelines. It provides a systematic, efficient, and economical repair solution for various grades of steel frame damage caused by environmental factors, media corrosion, and other factors during pipeline operation. This technical solution utilizes polymer filling, glass fiber composite reinforcement layer protection, and viscoelastic and polypropylene anti-corrosion layer restoration to restore and enhance the overall strength and corrosion resistance of the pipeline, extending its service life.

[0006] 1. Level 1 repair plan (external anti-corrosion layer damaged, steel frame intact)

[0007] (1) Repair structure: From the inside to the outside, it is the sewage pipe, polymer filling layer, viscoelastic anti-corrosion layer, and polypropylene anti-corrosion layer. The viscoelastic anti-corrosion layer is formed by spirally winding viscoelastic anti-corrosion tape, with an overlap width of ≥10mm and a joint overlap length of ≥50mm; the polypropylene anti-corrosion layer is formed by winding polypropylene anti-corrosion tape, with an overlap width of ≥50mm from the original anti-corrosion layer, first winding it in place for 2 turns, then spirally winding it with a circumferential overlap of 50% to 55%.

[0008] (2) Repair steps:

[0009] Defect Treatment: Thoroughly clean any defects on the outer protective layer of the pipe with anhydrous ethanol to remove dust and oil. Then, use a utility knife to trim the defects, ensuring there are no warped edges or protrusions, and clean any residue left during the trimming process.

[0010] Defect filling: Prepare an appropriate amount of polymer material and fill the defective area after repair. The filling should be full and flush with the outer protective layer of the pipe. During the filling process, operators must wear disposable gloves to prevent contamination with oil.

[0011] External corrosion protection: First, wrap viscoelastic anti-corrosion tape continuously in a spiral pattern over the completed polymer layer, with an overlap width of ≥10mm and an overlap length of ≥50mm at the joints. Then, wrap polypropylene anti-corrosion tape over the viscoelastic layer, starting with the original pipeline anti-corrosion layer, with an overlap width of ≥50mm. Wrap in-situ (at least two turns) and then spirally wrap, with an overlap of 50% to 55% circumferentially, until the overlap width at the other end is also ≥50mm with the original pipeline anti-corrosion layer, and wrap in-situ (at least two turns).

[0012] 2. Secondary repair plan (steel body exposed on the surface of the steel skeleton)

[0013] (1) Repair structure: Based on the primary repair structure, add a composite material reinforcement layer (2 layers). The glass fiber composite material reinforcement layer is composed of glass fiber cloth and reinforcing repair adhesive. The width of each layer is 320mm±10mm. The thickness of the adhesive coating between layers is 0.6mm to 0.8mm, and the coating area extends more than 12mm beyond the ends of the glass fiber cloth.

[0014] (2) Additional step: Composite material reinforcement layer protection

[0015] Reinforcement adhesive preparation: Stir the reinforcement and repair adhesive components A and B according to the proportion for 3 to 5 minutes. Use after visual inspection to see if there is no color difference. The prepared adhesive should be used within 30 minutes at room temperature (25℃).

[0016] Apply primer: Apply reinforcing and repairing adhesive primer on the surface of the pipe. The width of the coating area should exceed the width of the glass fiber cloth by more than 10mm at both ends.

[0017] Fiberglass Cloth Wrapping: Start wrapping the fiberglass cloth around the pipe at the 10 or 2 o'clock position, pulling firmly to ensure it adheres tightly to the pipe without wrinkles. Use a roller to squeeze the cloth after each layer to ensure the adhesive is fully soaked and free of hollows and bubbles. Wrap at least two layers, each of which must meet the required compression resistance.

[0018] Surface glue collection and finished product protection: After winding, the surface glue is collected and covered with a protective film to prevent contamination.

[0019] The remaining steps are the same as the first-level repair plan.

[0020] 3. Level 3 repair plan (there is floating rust and obvious scratches on the steel frame surface, and the crack depth is less than 0.2 times the wall thickness)

[0021] (1) Repair structure: Based on the secondary repair structure, the number of composite material reinforcement layers is increased to 6. The glass fiber composite reinforcement layer has a total of 6 layers, each layer has a winding angle of 90°±5°, and a total thickness of ≥5.5mm; each layer is rolled at least 3 times after winding.

[0022] (2) Additional steps: During the composite reinforcement layer protection process, the number of glass fiber cloth wrapping layers is increased to 6 to ensure full reinforcement of the damaged parts of the steel frame. The remaining steps are the same as the secondary repair plan.

[0023] 4. Level 4 repair plan (obvious corrosion penetration and cracking of the steel frame)

[0024] (1) Repair structure: The joint reinforcement protection layer includes:

[0025] Polymer materials fill the openings in the anti-corrosion layer;

[0026] At least two layers of glass fiber composite reinforcement (each layer width 320mm±10mm, interlayer adhesive thickness 0.6mm to 0.8mm);

[0027] Viscoelastic anti-corrosion layer and polypropylene anti-corrosion layer (lap width error ±2%, spiral winding overlap error ±2%);

[0028] The signal line jumper uses a wire with a diameter of 2.5mm±0.2mm, and the connection point is wrapped with more than 2 layers of waterproof insulating tape.

[0029] (2) Repair measures: For severely damaged steel skeleton parts, take thorough repair measures such as replacing pipes and crimping joints. Specific steps are designed and implemented according to the actual situation on site, including but not limited to cutting the damaged pipe section, preparing new pipe sections, connecting with crimping joints, and restoring the anti-corrosion layer. For the openings of the original anti-corrosion layer, refer to the reinforced layer protection structure in the secondary repair plan for reinforcement.

[0030] Beneficial effects

[0031] The in-service buried steel skeleton reinforced polyethylene oil and gas field sewage pipeline repair structure provided by the utility model has significant beneficial effects compared with traditional repair methods, which are specifically reflected in the following aspects:

[0032] Stable structure and long-lasting repair effect: A polymer filler precisely fills defects in the pipeline's outer protective layer, combined with a multi-layer glass fiber composite reinforcement layer, significantly enhancing the mechanical strength and corrosion resistance of the repaired area. The dual-layer protection of viscoelastic and polypropylene anti-corrosion coatings ensures long-term corrosion protection of the repaired area, extending the service life of the pipeline.

[0033] Flexible Adaptability and Wide Applicability: This repair structure can flexibly adjust repair plans based on the severity of pipeline damage. For example, different numbers of reinforcement layers can be used for damage levels one through four, making repair measures more precise and effective. Furthermore, by adjusting the amount of polymer material filling, the number of glass fiber composite reinforcement layers, and the anti-corrosion layer winding parameters, the structure can adapt to steel-reinforced polyethylene oil and gas field sewage pipelines of varying sizes, improving the versatility and practicality of the repair.

[0034] Simple construction and manageable costs: The repair process utilizes modular, standardized materials and processes, simplifying construction steps and reducing both difficulty and cost. Furthermore, the long-lasting repair effect reduces the additional costs associated with frequent repairs, further reducing the overall cost of pipeline maintenance.

[0035] Safety, environmental protection, and risk reduction: During the repair process, stringent safety and environmental protection measures were implemented to effectively reduce risks to the environment and personnel health. For example, the use of anhydrous ethanol to clean the pipe surface and the wearing of protective equipment during construction ensured the safety and environmental friendliness of the construction process.

[0036] Signal continuity for easy detection: A signal post is installed at the repair joint location, and a signal line is connected to both ends of the pipeline to ensure pipeline signal continuity and joint detectability. This design not only facilitates subsequent pipeline inspection and maintenance work, but also improves the safety and reliability of pipeline operation.

[0037] To sum up, the in-service buried steel skeleton reinforced polyethylene oil and gas field sewage pipeline repair structure provided by the utility model shows significant beneficial effects in terms of structural stability, scope of application, construction cost, safety and environmental protection, and signal continuity, and is of great significance for improving the operating efficiency and safety of oil and gas field sewage pipelines. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of this patent, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of this patent and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0039] Figure 1This is a schematic diagram of the repair structure for the first-level point outer protective layer, showing the repair structure schematic for the first-level damage level (the outer anti-corrosion layer of the steel strip reinforced composite pipe is damaged, and the steel skeleton is not damaged). From inside to outside, they are:

[0040] 101-Sewage pipe: The core pipe part, carrying sewage.

[0041] 102-Polymer material: Polymer material used to fill the defective parts of the outer protective layer of the pipeline and to repair the damage of the anti-corrosion layer.

[0042] 103-Viscoelastic: Viscoelastic anti-corrosion tape that provides an outer layer of corrosion protection for the filled polymer material, providing a preliminary anti-corrosion barrier.

[0043] 104-Polypropylene: On the outer layer of the viscoelastic anti-corrosion tape, polypropylene anti-corrosion tape is further spirally wrapped to ensure the integrity and durability of the anti-corrosion layer.

[0044] Figure 2 This is a schematic diagram of the secondary point reinforcement layer protection structure, showing the repair structure diagram for the second level of damage (steel skeleton surface exposed steel body). From inside to outside:

[0045] 201-Sewage pipe: core pipe section.

[0046] 202-Polymer material: polymer material that fills the defects of the anti-corrosion layer.

[0047] 203-Composite material reinforcement layer (2 layers): After filling the anti-corrosion layer, use glass fiber composite material reinforcement layer to wrap at least two layers to enhance the mechanical strength and anti-corrosion performance of the pipeline.

[0048] 204-Viscoelastic: Viscoelastic anti-corrosion tape for external corrosion protection of composite reinforcement layers.

[0049] 205-Polypropylene: The outermost layer is polypropylene anti-corrosion tape, which is continuously spirally wound to ensure the integrity and durability of the anti-corrosion layer.

[0050] Figure 3 This is a schematic diagram of the structure for the reinforcement and repair of a three-level steel strip-reinforced sewage pipe, showing the repair structure for the third level of damage (rust and obvious scratches on the steel skeleton surface, and crack depth less than 0.2 times the wall thickness). From inside to outside:

[0051] 301-Sewage pipe: core pipe part.

[0052] 302-Polymer material: polymer material used to fill the damaged parts of the anti-corrosion layer and steel frame.

[0053] 303- Damaged parts of the steel skeleton: Directly showing the damaged parts of the steel skeleton that are still visible after filling with polymer materials.

[0054] 304-composite reinforcement layer (6 layers): Six layers of glass fiber composite material are used to reinforce and wrap around the damaged area, greatly improving the strength and corrosion resistance of the pipeline.

[0055] 305-Viscoelastic: Viscoelastic anti-corrosion tape for external corrosion protection of composite reinforcement layers.

[0056] 306-Polypropylene: The outermost layer is polypropylene anti-corrosion tape, which ensures the integrity and long-term effectiveness of the overall anti-corrosion layer.

[0057] Figure 4 The signal line wiring repair structure after replacing the connector at the fourth-level point shows the structure where the opening of the original anti-corrosion layer needs to be strengthened during the repair process of the fourth-level damage level (obvious corrosion penetration and cracking of the steel frame). From the inside to the outside, they are:

[0058] 401-Sewage pipe joint: Replace the previously damaged level 4 damage point with a steel joint and repair it near the steel joint.

[0059] 402-Sewage pipe: core pipe section.

[0060] 403-Polymer material: Polymer material used to fill openings or defects in the anti-corrosion layer.

[0061] 404-Steel Tape Connector Signal Wire: Signal wire that may be present at the joint for monitoring or control purposes.

[0062] 405-Signal line: The purpose of the signal line is to be used as an access point for connecting electrical signals for subsequent pipeline damage point detection.

[0063] 406-Composite material reinforcement layer (6 layers): A glass fiber composite material layer that is specially reinforced at the opening position of the original anti-corrosion layer, with at least six layers wrapped around it.

[0064] 407-Viscoelastic: Viscoelastic anti-corrosion tape for external corrosion protection of composite reinforcement layers.

[0065] 408-Polypropylene: The outermost layer is polypropylene anti-corrosion tape to ensure the integrity of the anti-corrosion layer and long-term protection effect. DETAILED DESCRIPTION

[0066] The following is a specific implementation method for the repair structure of an in-service buried steel skeleton reinforced polyethylene oil and gas field sewage pipeline, which aims to elaborate on the specific operating steps and precautions of each level of repair plan.

[0067] 1. Implementation Methods of the First-Level Restoration Plan

[0068] Step 1: Defect handling

[0069] Prepare tools and materials: anhydrous ethanol, utility knife, cleaning cloth, personal protective equipment (such as gloves, goggles).

[0070] Procedure: First, thoroughly clean the defective area of ​​the pipe's outer protective layer with anhydrous ethanol to remove surface dust and oil. Then, use a utility knife to trim the edges of the defect, ensuring there are no warping or protrusions. Any residue generated during the trimming process should be promptly cleaned to prevent it from affecting subsequent steps.

[0071] Step 2: Filling the gaps

[0072] Prepare materials: polymer materials, disposable gloves.

[0073] Operation process: Prepare the appropriate amount of polymer material according to the size of the defect, ensuring that the material is uniform and free of impurities. Wearing disposable gloves, the operator evenly applies the prepared polymer material to the defect area, ensuring that the material is fully filled and flush with the outer protective layer of the pipe. After filling, wait for the material to solidify.

[0074] Step 3: External corrosion protection

[0075] Prepare materials: viscoelastic anti-corrosion tape, polypropylene anti-corrosion tape, and measuring tools (such as a tape measure).

[0076] Procedure: First, wrap the viscoelastic anti-corrosion tape in a continuous spiral around the filled defect, with an overlap width of at least 10mm and an overlap length of at least 50mm at the joint. Next, wrap the polypropylene anti-corrosion tape over the viscoelastic layer, starting from the original pipe coating with an overlap width of at least 50mm. Wrap at least two turns in situ, then spirally wrap with a 50% to 55% overlap around the pipe, until the other end also overlaps the original pipe coating with a width of at least 50mm, and wrap at least two more turns in situ. Keep the tape flat, free of wrinkles and bubbles, during the wrapping process.

[0077] Implementation of the Secondary Restoration Plan

[0078] On the basis of the first-level repair scheme, a composite material reinforcement layer protection step is added. The specific implementation is as follows:

[0079] Reinforcement Adhesive Preparation: Thoroughly stir the A and B components of the reinforcement and repair adhesive according to the proportions for 3 to 5 minutes until there is no visual color difference. The prepared adhesive must be used within 30 minutes at room temperature (25°C).

[0080] Apply primer: Apply reinforcing and repairing adhesive primer to the areas on the pipe surface that need to be strengthened. The width of the applied area must exceed the width of the glass fiber cloth by more than 10mm at both ends to ensure that the glass fiber cloth can fully fit the pipe body.

[0081] Fiberglass Cloth Wrapping: Begin wrapping the fiberglass cloth around the pipe at the 10 or 2 o'clock position, pulling firmly to ensure it adheres tightly to the pipe without wrinkles. After each layer, use a roller to squeeze the cloth to ensure the adhesive is fully soaked and free of hollows and bubbles. Wrap at least two layers, each of which must meet compressive strength requirements. Keep the surface of the fiberglass cloth clean during wrapping to avoid dust and other impurities that could affect the repair quality.

[0082] Surface glue removal and finished product protection: After wrapping, the outermost surface is glued as needed to ensure a beautiful appearance. Then, a protective film is used to protect the surface of the reinforcement to prevent dust, oil, and other impurities from contaminating the uncured composite adhesive.

[0083] The remaining steps are the same as the first-level repair plan.

[0084] 3. Implementation Methods of the Three-Level Restoration Plan

[0085] Based on the secondary repair plan, the number of fiberglass cloth wrapping layers is increased to 6 to address more severe steel frame damage. The specific implementation steps are similar to the secondary repair plan, differing only in the number of fiberglass cloth wrapping layers.

[0086] 4. Implementation Methods of the Four-Level Restoration Plan

[0087] For Grade 4 damage, where the steel frame is obviously corroded, penetrated, or cracked, a complete repair measure involving pipe replacement and crimping joints is adopted. Specific implementation steps must be designed and executed based on the actual site conditions, and typically include the following key steps:

[0088] Cutting the damaged pipe section: Use professional tools to cut off the damaged pipe section.

[0089] Prepare new pipe sections: Prepare new pipe sections of corresponding length according to the size of the cut pipe, and ensure that the quality of the new pipe sections meets the relevant standards.

[0090] Press-fit connections: Install a press-fit fitting between the new and old pipe sections and tighten the connection according to the manufacturer's instructions.

[0091] Restoring the anti-corrosion coating: After the crimped joint is connected, restore the anti-corrosion coating on the interface and the new pipe section. For specific methods, refer to the external anti-corrosion protection steps in the secondary or tertiary repair plan. For openings in the original anti-corrosion coating, special protection is required. Refer to the enhanced layer protection structure in the secondary repair plan for implementation.

[0092] Through the above-mentioned specific implementation methods, it can be ensured that the in-service buried steel skeleton reinforced polyethylene oil and gas field sewage pipeline can be effectively repaired at different damage levels, thereby improving the overall strength and corrosion resistance of the pipeline and extending its service life.

Claims

1. A repair structure for an in-service buried steel skeleton reinforced polyethylene oil and gas field sewage pipeline, characterized in that: According to the damage level of steel skeleton reinforced polyethylene oil and gas field sewage pipeline, four levels of repair structure are divided. The specific judgment basis and repair structure are as follows: The first-level repair structure is determined based on the fact that the outer anti-corrosion layer of the steel-strip reinforced composite pipe is damaged but the steel skeleton is not damaged. The repair structure is to restore the anti-corrosion layer, and use a viscoelastic anti-corrosion layer plus a polypropylene anti-corrosion layer for anti-corrosion protection; The second-level repair structure is determined based on the steel body being exposed on the surface of the steel skeleton but not yet penetrated or severely corroded. The repaired structure is protected by at least two layers of glass fiber composite reinforcement layer on the basis of the restoration of the anti-corrosion layer, and then a viscoelastic anti-corrosion layer and a polypropylene anti-corrosion layer; The criteria for determining a Grade 3 repair structure are that the steel skeleton surface has rust, obvious scratches, or cracks with a depth less than 0.2 times the wall thickness. The repair structure uses at least six layers of glass fiber composite reinforcement, plus a viscoelastic anti-corrosion layer and a polypropylene anti-corrosion layer; The basis for determining the fourth-level repair structure is that the steel frame is obviously corroded or cracked and cannot be repaired locally. The repair structure is to replace the pipes at the damaged parts and install crimped joints, and set up joint reinforcement protection layers at the joints, including filling the openings of the anti-corrosion layer with polymer materials, adding at least six layers of glass fiber composite material reinforcement layers, and then adding viscoelastic anti-corrosion layers and polypropylene anti-corrosion layers.

2. The repair structure according to claim 1, characterized in that The specific requirements for the first-level repair structure are as follows: The thickness of the polymer material filling layer is 2mm to 3mm; The overlap width of the spirally wound viscoelastic anti-corrosion layer is 10mm±1mm, and the overlap length at the joint is 50mm to 60mm; The polypropylene anti-corrosion layer is wrapped around the original anti-corrosion layer of the pipeline with an overlap width of 50mm±5mm. First, at least two turns of winding are performed to closely fit the original anti-corrosion layer, and then at least three turns of spiral winding are performed, with an overlap rate of 50% to 55% for each spiral winding.

3. The repair structure according to claim 1, characterized in that Specific requirements for secondary repair structures include: There shall be at least two layers of glass fiber composite reinforcement, and the width of each layer of glass fiber cloth shall be 320mm±10mm; The thickness of the reinforcing and repairing adhesive applied between layers should be 0.6mm to 0.8mm, and the width of the applied area should extend at least 12mm beyond both ends of the glass fiber cloth; The winding parameters of the external viscoelastic anti-corrosion layer and the polypropylene anti-corrosion layer are the same as those of the primary repair structure.

4. The repair structure according to claim 1, characterized in that The specific requirements for the third-level repair structure are as follows: The glass fiber composite reinforcement layer consists of six layers, and the winding angle of each layer is 90°±5°; The total thickness of the reinforcement layer shall not be less than 5.5mm; Each layer of fiberglass cloth is rolled and squeezed at least three times; The winding parameters of the external viscoelastic anti-corrosion layer and the polypropylene anti-corrosion layer are the same as those of the primary repair structure.

5. The repair structure according to claim 1, characterized in that Specific requirements for the fourth-level repair structure include: The joint reinforcement layer shall have at least two layers of glass fiber composite material reinforcement, with each layer width of 320mm±10mm and interlayer adhesive thickness of 0.6mm to 0.8mm; The diameter of the signal line of the pipes at both ends of the signal pile jumper joint is 2.5mm±0.2mm, and the signal line connection point should be wrapped with at least two layers of waterproof insulation tape; The winding parameters of the viscoelastic anti-corrosion layer and the polypropylene anti-corrosion layer outside the reinforcement layer are the same as those of the primary repair structure, and the errors of the lap width and the spiral winding overlap rate are controlled within the range of ±2%.

Images