Sectional foam concrete pouring and filling structure of in-service oil and gas pipeline

Abstract

The utility model provides a segmental foam concrete pouring structure of an in-service oil and gas pipeline, which is applied to the technical field of oil and gas pipeline disease treatment engineering and comprises a lining structure, and a placing space for accommodating the in-service oil and gas pipeline is arranged in the lining structure. The placing space is provided with a pouring cavity at least comprising a pouring material opening and a pipeline inlet and outlet, and the in-service oil and gas pipeline penetrates through the pipeline inlet and outlet; the utility model further provides a sectional foam concrete filling structure of the in-service oil and gas pipeline, the sectional foam concrete filling structure at least comprises two sectional foam concrete pouring structures of the in-service oil and gas pipeline and further comprises foam concrete poured into the pouring cavity through the pouring material opening, and the foam concrete is used for fixing the in-service oil and gas pipeline. Foam concrete is adopted for disease treatment of the in-service oil-gas pipeline, it is guaranteed that the oil-gas pipeline is constructed without gas interruption, the labor cost and the disease treatment cost are greatly reduced, and the treatment construction efficiency is greatly improved.

Description

Technical Field

[0001] This application relates to the field of engineering technology for the treatment of defects in oil and gas pipelines, and more specifically, to a segmental foamed concrete casting and filling structure for in-service oil and gas pipelines. Background Technology

[0002] Oil and gas pipelines serve as the primary carriers of petroleum, natural gas, and other products, and are crucial energy infrastructure for promoting national economic development and social progress. According to incomplete statistics, by the end of 2023, the total length of long-distance oil and gas pipelines in my country reached 183,000 kilometers, essentially forming an oil and gas network spanning east to west, north to south, covering the entire country, and connecting overseas. As a typical linear structure, oil and gas pipelines traverse highly variable terrain and geological conditions. During long-term operation, influenced by factors such as transport pressure, thermal expansion and subsidence, environmental corrosion, and geological activity, pipelines inevitably experience excessive local deformation, leading to localized stress concentration, resulting in problems such as uplift and voids, and in severe cases, even pipeline leaks or explosions.

[0003] Currently, the common method for treating defects in existing oil and gas pipelines is sandbag counterpressure. This method controls the vertical upward floating deformation and lateral swaying deformation of the pipeline by increasing the load on the pipeline and the interface friction between the sandbags and the pipeline. However, the treatment of defects in in-service oil and gas pipelines often faces challenges such as tight construction schedules, limited working space, and the need for uninterrupted gas supply. Due to the narrow working space, the sandbag counterpressure method requires manual handling, resulting in high labor costs, extremely low construction efficiency, and high construction risks. Furthermore, due to the need for self-stabilization when stacking sandbags, a slope must be maintained from top to bottom, leading to uneven lateral stress along the pipeline during counterpressure construction. Over time, this can easily cause secondary damage to the oil and gas pipeline due to eccentric deformation.

[0004] Therefore, for the treatment of deformation defects in in-service pipelines, there is an urgent need for a segmented foamed concrete casting and filling structure that has high construction efficiency, good deformation control effect, and can effectively fix the pipeline. Utility Model Content

[0005] To address the problems of long construction cycles, poor treatment effects, and inability to maintain gas supply during the treatment of deformation defects in existing oil and gas pipelines using the sandbag counterpressure method, this application proposes a segmental foamed concrete casting and filling structure for existing oil and gas pipelines. This reduces labor and treatment costs, improves treatment efficiency, and ensures the operational safety of oil and gas pipelines.

[0006] In the first aspect, this application provides a segmental foamed concrete casting structure for in-service oil and gas pipelines, the technical solution of which is as follows:

[0007] The system includes a lining structure, within which a space is provided for accommodating an in-service oil and gas pipeline. The space is provided with a casting cavity including at least a casting inlet and a pipeline inlet / outlet, through which the in-service oil and gas pipeline passes.

[0008] This application provides a segmental foamed concrete casting structure for in-service oil and gas pipelines. The lining structure serves as the foundation for the entire casting structure, accommodating the in-service oil and gas pipelines and providing support and protection. The lining structure can be a cast-in-place concrete structure, its size and shape designed according to actual engineering needs to adapt to oil and gas pipelines of different diameters and underground environments. It also includes a casting cavity located inside the lining structure, connected to the in-service oil and gas pipeline via pipeline inlets and outlets, ensuring sufficient support for the space surrounding the pipeline to accommodate the foamed concrete and limiting pipeline deformation.

[0009] Furthermore, this application also proposes to include a lateral support structure disposed within the placement space, for forming the casting cavity with the inner wall of the lining structure.

[0010] This application provides a segmental foamed concrete casting structure for in-service oil and gas pipelines. The lateral support structure and the lining structure together form an integral load-bearing structure, allowing the foamed concrete and the pipeline to share the load, avoiding local stress concentration, and improving the stability and safety of the structure. The presence of the lateral support structure can prevent the foamed concrete from collapsing or deforming during the casting process, thereby improving the casting quality. It effectively solves the problems existing in the treatment of defects in in-service oil and gas pipelines, and has the advantages of high construction efficiency, strong adaptability, good safety, and good treatment effect, which can effectively improve the safe operation level of oil and gas pipelines.

[0011] Furthermore, this application also proposes that the lateral support structure is provided in one form, and the lateral support structure, together with the side inner wall structure, bottom inner wall structure, front inner wall structure and back inner wall structure of the lining structure, constitute the casting cavity.

[0012] This application provides a segmental foamed concrete casting structure for an in-service oil and gas pipeline. Lateral support structures are placed inside the casting cavity, forming the cavity together with the side, bottom, front, and back inner wall structures of the lining structure, and providing lateral support. The lining structure provides physical protection for the in-service oil and gas pipeline, preventing it from being affected by external environmental factors such as soil pressure and groundwater erosion. Each lateral support structure and the lining structure together form an integral load-bearing structure, allowing the foamed concrete and the pipeline to share the load, avoiding localized stress concentration, and improving the stability and safety of the structure.

[0013] Furthermore, this application also proposes that the lateral support structure is a cast-in-place or precast reinforced concrete slab, and the thickness of the lateral support structure is greater than 15cm.

[0014] Furthermore, this application also proposes to include a horizontal support structure disposed within the placement space, one end of which is connected to the lateral support structure for supporting the lateral support structure, and the other end of which is connected to the inner wall of the lining structure.

[0015] This application provides a segmental foamed concrete casting structure for an in-service oil and gas pipeline. The lateral support structure, horizontal support structure, and lining structure together form an integral load-bearing structure, so that the foamed concrete and the pipeline share the load, avoiding local stress concentration and improving the stability and safety of the structure. The use of a single lateral support structure and a horizontal support structure can simplify the structural design, reduce construction difficulty and cost, and the horizontal support structure can effectively prevent lateral deformation of the lateral support structure and enhance the overall stability of the structure.

[0016] Furthermore, this application also proposes that the installation height of the horizontal support structure is 1 / 2 to 3 / 4 of the height of the lateral support structure.

[0017] By setting up a horizontal support structure, lateral deformation of the lateral support structure can be effectively prevented, and the overall stability of the structure can be enhanced. The installation height of the horizontal support structure is 1 / 2 to 3 / 4 of the height of the lateral support structure, which can effectively distribute the horizontal load and prevent the lateral support structure from becoming unstable due to the horizontal support structure being too short.

[0018] Furthermore, this application also proposes that the horizontal support structure is one or more of the following: I-beams, steel pipes, angle steel, and square steel.

[0019] Furthermore, this application also proposes that the top of the lining structure is an outwardly convex arched structure.

[0020] The arched design of the lining structure can enhance the compressive and bending resistance of the structure, improve the overall stability of the structure, effectively distribute vertical loads, and reduce stress concentration.

[0021] Secondly, this application provides a segmental foamed concrete filling structure for in-service oil and gas pipelines, comprising at least two segmental foamed concrete casting structures for in-service oil and gas pipelines as described in the first aspect, the technical solution of which is as follows:

[0022] It also includes foamed concrete poured into the casting cavity through the casting port, the foamed concrete being used to fix the in-service oil and gas pipeline.

[0023] Furthermore, this application also proposes that at least two foamed concretes are provided, and the distance between two adjacent foamed concretes is 20m to 60m;

[0024] The distance between the outer surface of the casting cavity and the outer surface of the in-service oil and gas pipeline is greater than 20cm.

[0025] This application provides a segmental foamed concrete filling structure for in-service oil and gas pipelines. This segmental filling structure allows for targeted reinforcement based on pipeline deformation, improving treatment effectiveness, reducing foamed concrete usage, and shortening the construction period. Simultaneously, the segmental design avoids the high hydration heat release phenomenon caused by excessively large volumes of single-unit foamed concrete pours, preventing additional thermal stress from hydration-induced temperature rise that could lead to further thermal expansion and deformation of the pipeline, thus ensuring its safe operation.

[0026] Beneficial effects: This application uses foamed concrete for the treatment of defects in in-service oil and gas pipelines. Utilizing the good fluidity of foamed concrete and the convenience of long-distance pipeline pumping and pouring, it can adapt to the complex environment of in-service oil and gas pipeline tunnels, ensuring uninterrupted gas supply during construction. It significantly reduces labor and defect treatment costs, greatly improving construction efficiency. The inherent strength of foamed concrete effectively fixes the pipeline, reducing the risk of deformation due to temperature, transport pressure, and geological activity. Through lateral support structures, horizontal support structures, lining structures, and segmented foamed concrete forming an integral load-bearing structure, the lateral deformation of the operating pipeline is effectively limited, greatly reducing the risk of horizontal swaying displacement and ensuring the operational safety of the oil and gas pipeline. The segmented foamed concrete filling structure design can target severely deformed and excessively stressed areas of pipelines within tunnels for targeted treatment and hazard mitigation. This allows for precise reinforcement of pipeline deformation and potential hazards, effectively reducing the risk of future pipeline deformation and lowering maintenance costs. On one hand, it minimizes the volume of foam filling while ensuring effective treatment, shortening the construction period and avoiding any impact on the operation of in-service pipelines. On the other hand, the segmented filling design solves the problem of high hydration heat release caused by excessive single-unit foamed concrete pouring, preventing additional thermal stress from hydration heating that could lead to further thermal expansion and deformation of the pipeline, thus ensuring safe operation. Attached Figure Description

[0027] Figure 1 This application provides a structural schematic diagram of a segmental foamed concrete casting and filling structure for an in-service oil and gas pipeline.

[0028] Figure 2 This application provides a top view of a segmental foamed concrete casting and filling structure for an in-service oil and gas pipeline.

[0029] In the diagram: 1. Lining structure; 2. In-service oil and gas pipeline; 3. Casting cavity; 4. Lateral support structure; 5. Horizontal support structure; 6. Foamed concrete; 61. First segment of foamed concrete; 62. Second segment of foamed concrete. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and marked in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0031] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0032] During long-term operation, oil and gas pipelines are inevitably affected by factors such as transport pressure, thermal expansion and subsidence, environmental corrosion, and geological activity. This inevitably leads to excessive local deformation, causing localized stress concentration and resulting in defects such as bulging and voiding. In severe cases, it can even cause pipeline leaks or explosions. Currently, the common method for treating defects in existing oil and gas pipelines is sandbag counterpressure. This method increases the load on the pipeline and the interface friction between the sandbags and the pipeline, thereby controlling the vertical upward floating deformation and lateral swaying deformation of the pipeline. However, the treatment of defects in in-service oil and gas pipelines often faces challenges such as tight construction schedules, limited working space, and the need for uninterrupted gas supply. Due to the narrow working space, the sandbag counterpressure method requires manual handling, resulting in high labor costs, extremely low construction efficiency, and high construction risks. Furthermore, due to the need for self-stabilization when stacking sandbags, a slope must be maintained from top to bottom, leading to uneven lateral stress along the pipeline during counterpressure construction. Over time, this can easily cause secondary damage to the oil and gas pipeline due to eccentric deformation.

[0033] To address this issue, this application proposes a segmental foamed concrete casting structure for in-service oil and gas pipelines, including a lining structure 1. The lining structure 1 has a placement space for accommodating the in-service oil and gas pipeline 2. The placement space has a casting cavity 3 that includes at least a casting inlet and a pipeline inlet / outlet. The in-service oil and gas pipeline 2 passes through the pipeline inlet / outlet.

[0034] Please refer to Figure 1 The in-service oil and gas pipeline 2 has a diameter of 864mm, 1016mm, or 1219mm. The lining structure 1 is composed of cast-in-place concrete, forming a robust shell with a concrete strength grade of C50 to C80. The lining structure 1 is the foundation of the entire cast-in-place structure, used to enclose and protect the in-service oil and gas pipeline 2, providing sufficient space for the pipeline. The thickness and strength of the lining structure 1 are determined based on the pipeline diameter, burial depth, the properties of the surrounding soil, and the expected load. Inside the lining structure 1, a placement space is provided specifically for accommodating the in-service oil and gas pipeline 2. The design of the placement space takes into account the size of the pipeline and the space required for maintenance, ensuring that the pipeline can be freely placed within the lining structure 1 while leaving sufficient space for the pouring of foamed concrete 6. The pouring cavity 3 is a cavity formed within the placement space, which includes at least one pouring inlet and one pipeline inlet / outlet. The pouring inlet is used to deliver the foamed concrete 6 into the pouring cavity 3, while the pipeline inlet / outlet allows the in-service oil and gas pipeline 2 to pass through while maintaining its connection with the pouring cavity 3. The pouring inlet is typically located at the top or side of the lining structure 1, through which foamed concrete 6 can be pumped into the pouring cavity 3. The design of the pouring inlet takes into account the flowability of the concrete and ease of construction, allowing for the passage of long-distance foamed concrete pumping pipelines. The pipeline inlet and outlet are openings located on the side of the pouring cavity 3, their dimensions matching the diameter of the in-service oil and gas pipeline 2 to ensure smooth pipeline passage. The design of the pipeline inlet and outlet considers sealing performance to prevent foamed concrete 6 from leaking outside the pouring cavity 3, while also ensuring the stability of the pipeline within the pouring cavity 3.

[0035] Furthermore, in some preferred embodiments, a lateral support structure 4 is also included within the placement space to form a pouring cavity 3 with the inner wall of the lining structure 1. This structure can also adjust the size of the pouring cavity 3. This design aims to enhance the stability of the pouring cavity 3 and prevent lateral movement or collapse of the foamed concrete 6 during pouring. The lateral support structure 4 can be a steel mesh, bracket, partition, or other form of support element fixed to the inner wall of the lining structure 1. They are fixed to the inner wall of the lining structure 1 and arranged at certain intervals and angles to form a robust frame supporting the weight of the foamed concrete 6. The connection between the lateral support structure 4 and the lining structure 1 can be welding, bolting, or other mechanical fixing methods to ensure that the lateral support structure 4 remains stable during pouring and will not shift or be damaged by external forces.

[0036] In some specific embodiments, two lateral support structures 4 may be provided, with the casting cavity 3 located between the two lateral support structures 4. Together, they define the space of the casting cavity 3. This layout allows the foamed concrete 6 to be poured evenly from both sides, ensuring a uniform distribution of the foamed concrete 6 around the in-service oil and gas pipeline 2. This is crucial for ensuring the uniform curing of the foamed concrete 6 and the overall stability of the structure. The design of the double lateral support structure 4 simplifies the construction process, improves construction efficiency, provides additional support points, enhances the stability of the casting cavity 3, and prevents deformation or damage to the casting cavity 3 during the pouring and curing of the foamed concrete 6. The double lateral support structure 4 provides a clear casting boundary, which helps to improve the control of casting quality.

[0037] In one preferred embodiment, a lateral support structure 4 is provided. The lateral support structure 4, together with the side inner wall structure, bottom inner wall structure, front inner wall structure and back inner wall structure of the lining structure 1, forms the casting cavity 3, which can save the amount of lateral support structure 4 used, thereby reducing costs.

[0038] One lateral support structure 4 is provided, meaning that within each segment of the lining structure 1, only one lateral support structure 4, together with the various inner wall structures of the lining structure 1, forms the casting cavity 3. The lateral support structure 4 is located inside the lining structure 1, forming the casting cavity 3 together with the side, bottom, front, and back inner walls of the lining structure. This design ensures the integrity and stability of the casting cavity 3. The lateral support structure 4 is tightly integrated with the inner wall of the lining structure 1, forming a closed casting space. This structural design ensures that the foamed concrete 6 can be uniformly cast around the in-service oil and gas pipeline 2, providing the necessary support and fixation. The design of the lateral support structure 4 simplifies the construction process because it provides a clear boundary, making it easier for construction personnel to control the casting direction and volume of the foamed concrete 6. The precise fit between the lateral support structure 4 and the inner wall structure of the lining structure 1 ensures that the foamed concrete 6 can be accurately cast in the predetermined area. The lateral support structure 4 enhances the structural strength of the casting cavity 3, enabling it to withstand the pressure generated during the casting of the foamed concrete 6.

[0039] Furthermore, in some preferred embodiments, the lateral support structure 4 can be a cast-in-place or precast reinforced concrete slab with a concrete grade of C15 to C25 and a slab thickness of not less than 15cm.

[0040] The lateral support structure 4 is preferably constructed of reinforced concrete slabs, a material widely favored for its high strength and durability. The use of reinforced concrete ensures the stability of the lateral support structure 4 under the pressure generated during the pouring of the foamed concrete 6. While cast-in-place concrete allows for direct pouring on-site, better adapting to site conditions and the specific dimensions of the pipeline, precast concrete slabs can be prefabricated in a factory to ensure quality and consistency before being transported to the site for installation. The concrete grade for the lateral support structure 4 is selected from C15 to C25, providing sufficient strength and durability to withstand structural loads and environmental impacts. The slab thickness of the lateral support structure 4 is no less than 15 cm, ensuring structural stability and load-bearing capacity while providing sufficient protective layer to prevent corrosion of the internal reinforcement and structural damage. To further enhance the stability of the lateral support structure 4, steel fibers can be incorporated into the reinforced concrete slab. Such composite slabs exhibit better crack resistance and durability, making them suitable for oil and gas pipelines exposed to harsh environments for extended periods.

[0041] By adopting the aforementioned preferred design and material selection for the lateral support structure 4, structural stability can be improved. The use of reinforced concrete enhances the stability and load-bearing capacity of the entire segmental foamed concrete cast-in-place structure. The options for cast-in-place and precast construction provide flexibility to adapt to different engineering needs and site conditions. Concrete grades from C15 to C25 ensure the durability of the lateral support structure 4, enabling it to withstand long-term loads and environmental erosion. A slab thickness of at least 15 cm provides additional safety, ensuring the reliability and long-term stability of the structure. Through these preferred embodiments, the segmental foamed concrete cast-in-place structure of this application not only provides effective support but also ensures the long-term stability and safety of the entire structure, offering a reliable solution for the reinforcement and protection of in-service oil and gas pipelines.

[0042] Furthermore, in some preferred embodiments, a horizontal support structure 5 is also included, which is disposed in the placement space. One end of the horizontal support structure 4 is connected to the lateral support structure 4 to support the lateral support structure 4, and the other end is connected to the inner wall of the lining structure 1.

[0043] One end of the horizontal support structure 5 is connected to the lateral support structure 4. This connection is designed to support the lateral support structure 4, ensuring its stability during the pouring process and preventing displacement or deformation of the lateral support structure 4 during the pouring of foamed concrete 6. This supporting function is crucial for maintaining the integrity and stability of the entire structure. The lateral support structure 4, the horizontal support structure 5, and the lining structure 1 together form an integral load-bearing structure, avoiding local stress concentration and improving the stability and safety of the poured structure.

[0044] Furthermore, in some preferred embodiments, the horizontal support structure 5 can be made of various materials, such as one or more of I-beams, steel pipes, angle steel, and square steel. These materials possess good strength and toughness, enabling them to withstand various loads during the casting process. The length of the horizontal support structure 5 is not less than 0.8m; the installation height of the horizontal support structure 5 is 1 / 2 to 3 / 4 of the height of the lateral support structure 4. This height range allows the horizontal support structure 5 to effectively support the lateral support structure 4 without affecting the pipe operating space. The installation height of the horizontal support structure 5 is designed to be 1 / 2 to 3 / 4 of the height of the lateral support structure 4. This ratio range is determined based on structural engineering principles and practical application requirements, aiming to achieve optimal support effect and structural balance. By installing the horizontal support structure 5 at 1 / 2 to 3 / 4 of the height of the lateral support structure 4, the load on the structure can be effectively distributed, while reducing instability factors caused by excessively high or low support points of the lateral support structure 4. This installation height helps to evenly distribute the pressure generated during the pouring of foamed concrete 6 onto the lateral support structure 4 and the lining structure 1, reducing local stress concentration and thus improving the overall stability and durability of the structure. Optimizing the installation height of the horizontal support structure 5 enhances the stability and deformation resistance of the entire cast-in-place structure. A reasonable support height helps to improve the structure's load-bearing capacity, enabling it to withstand greater loads. This design reduces construction risks.

[0045] The horizontal support structure 5 is designed to provide additional lateral force and top support. The horizontal support structure 5 can be connected to the lateral support structure 4 and the lining structure 1 via bolts to prevent the lateral support structure 4 from tilting or shifting during pouring. In some embodiments, one end of the horizontal support structure 5 can be connected to the lateral support structure 4 via bolts, welding, or other mechanical connections to ensure a secure and reliable connection. The other end of the horizontal support structure 5 is connected to the inner wall of the lining structure 1, and can be an anchor point, bracket, or other support element fixed to the lining structure 1 to provide stable support force. In one embodiment, the horizontal support structure 5 is made of I-beams, with one end connected to the lateral support structure 4 via high-strength bolts, and the other end fixed to the inner wall of the lining structure 1, forming a stable support system. In another embodiment, the horizontal support structure 5 uses a series of parallel steel pipes, which are evenly distributed on the outer surface of the lateral support structure 4 and fixed to the inner wall of the lining structure 1 by welding, effectively dispersing the pressure during the pouring process. In another embodiment, the horizontal support structure 5 includes a combination of angle steel and square steel, which provides stronger support and better stability, especially when the casting cavity is large or the foamed concrete is poured to a high height.

[0046] The addition of the horizontal support structure 5 significantly improves the stability of the entire cast-in-place structure, especially when the lateral support structure 4 is subjected to the pouring pressure of the foamed concrete 6. By connecting to the inner wall of the lining structure 1, the horizontal support structure 5 helps to distribute the load evenly, reduce local stress concentration, and improve the structure's durability. The material and dimensions of the horizontal support structure 5 can be adjusted according to specific engineering requirements to adapt to different loads and environmental conditions.

[0047] Furthermore, in some preferred embodiments, the top of the lining structure 1 is an outwardly convex arched structure.

[0048] The top of lining structure 1 features an outward-protruding arch design. This structure effectively distributes the load borne at the top evenly to the side walls, thereby improving the overall stability and compressive strength of the structure. The arch structure, utilizing its geometric properties, converts vertical loads into lateral forces, reducing the direct pressure on the top. This is particularly important for oil and gas pipeline linings subjected to heavy loads over long periods, enhancing the overall integrity and seismic resistance of the arch structure. It is suitable for reinforcing oil and gas pipelines in areas with complex geological conditions or frequent earthquakes. The arched design at the top of lining structure 1 helps to disperse the load on the structure, especially in the top area of ​​the pipeline tunnel. This design reduces the water pressure and soil lateral pressure acting directly on lining structure 1, thus improving the stability and durability of the structure. The arch structure, due to its geometric properties, can evenly distribute the load to both sides. This dispersion reduces concentrated stress on the structure, lowering the risk of lining structure 1 cracking or deforming. The arch structure has excellent bending resistance, which is crucial for withstanding changes in internal tunnel pressure and external environmental influences (such as geological activity). This structural design improves the adaptability of lining structure 1 to these dynamic loads. The construction of the arch structure is relatively simple and facilitates formwork support and concrete pouring. The continuity and integrity of the arch structure help improve the waterproof performance of the lining structure 1, reduce water penetration into the tunnel interior, and protect the in-service oil and gas pipeline 2 from water damage. Through the optimized design of the arch top, the stability and safety of the lining structure 1 are further improved, providing a strong guarantee for the long-term operation and maintenance of the in-service oil and gas pipeline 2.

[0049] This application also proposes a segmental foamed concrete filling structure for an in-service oil and gas pipeline, comprising at least two segmental foamed concrete casting structures for in-service oil and gas pipelines as described above, and further comprising foamed concrete 6 poured into the casting cavity 3 through a casting port, the foamed concrete 6 being used to fix the in-service oil and gas pipeline 2.

[0050] Please see Figure 2 ,like Figure 2As shown, the structure includes a first segment of foamed concrete 61 and a second segment of foamed concrete 62. A key innovation of this application lies in the segmented foamed concrete filling structure design, which achieves reinforcement and treatment of defects in oil and gas pipelines through this specific segmented design and construction method. The filling structure consists of multiple segments, each including a lining structure 1, a lateral support structure 4, a horizontal support structure 5, and a casting cavity 3. This segmented design allows for targeted reinforcement of different parts of the pipeline while providing flexibility to accommodate pipeline bending and uneven settlement. Foamed concrete 6 is poured into the casting cavity 3 through the pouring nozzle, completely encasing the in-service oil and gas pipeline 2, providing uniform support and fixation. The lightweight and high-strength properties of foamed concrete 6 make it an ideal filling material, reducing pressure on the pipeline while providing the necessary structural strength. Foamed concrete 6 serves not only as a filling material but also as a reinforcing material, fixing itself to the in-service oil and gas pipeline 2 through its own adhesion and friction, reducing displacement and deformation caused by temperature changes, pressure fluctuations, and geological activity.

[0051] The segmented casting structure and the support of foamed concrete 6 significantly improved the stability and deformation resistance of the in-service oil and gas pipeline 2. The segmented design allows construction to be carried out without affecting pipeline operation, enabling uninterrupted gas supply during construction. Targeted reinforcement treatment reduced the risk of future pipeline deformation and lowered maintenance costs. By limiting lateral deformation and horizontal sway displacement, the structure greatly reduced the risk of pipeline leakage or explosion, enhancing the operational safety of the oil and gas pipeline. It can provide targeted treatment and hazard mitigation for severely deformed pipelines and areas with excessive local stress within tunnels, enabling precise reinforcement of pipeline deformation and potential hazards. This effectively reduces the risk of future pipeline deformation and lowers maintenance costs. On one hand, it minimizes the amount of foam filling while ensuring effective treatment, shortening the construction period and avoiding any impact on the operation of in-service pipelines. On the other hand, the segmented filling design solves the problem of high hydration heat release caused by excessive single-unit foamed concrete pouring, preventing additional thermal stress from hydration heating that could lead to further thermal expansion and deformation of the pipeline, thus ensuring safe operation.

[0052] Furthermore, in some preferred embodiments, the foamed concrete 6 is formed by on-site casting and hardening through a long-distance pipeline, with a dry density grade of A08 to A12 and a strength grade of C3 to C10; at least two foamed concrete 6 are provided, and the number of casting structures corresponds to the number of foamed concrete 6. The foamed concrete 6 is transported into the corresponding casting structure and completely encloses the in-service oil and gas pipeline 2, and the distance between two adjacent foamed concrete 6 is 20m to 60m, which can also be understood as the distance between two adjacent casting structures is 20m to 60m. The length of the foamed concrete 6 is 12 to 25m, the height is 1.5 to 3m, the volume of a single foamed concrete 6 is not higher than 400 cubic meters, and the distance between the outer surface of the casting cavity 3 and the outer surface of the in-service oil and gas pipeline 2 is greater than 20cm.

[0053] Foamed concrete 6 is formed by on-site casting and hardening over long distances through the pipeline. This construction method allows foamed concrete 6 to solidify directly within the pipeline tunnel, providing higher construction efficiency and better adaptability. The dry density grade of foamed concrete 6 is A08 to A12. This range ensures that foamed concrete 6 has sufficient strength while maintaining its lightweight properties, reducing pressure on the in-service oil and gas pipeline 2 and the surrounding soil. The strength grade of foamed concrete 6 is C3 to C10. This range provides sufficient load-bearing capacity to support and secure the in-service oil and gas pipeline 2 while maintaining structural stability. At least two foamed concrete 6 sections are used, with a spacing of 20m to 60m between adjacent sections. This segmental arrangement allows for targeted reinforcement of different sections of the pipeline while providing flexibility to accommodate pipeline bends and uneven settlement. The length of foamed concrete 6 ranges from 12m to 25m, and the height from 1.5m to 3m. These dimensional requirements ensure that foamed concrete 6 can effectively encapsulate and secure the in-service oil and gas pipeline 2, while adapting to different pipeline sizes and tunnel conditions. The volume of a single foamed concrete 6 pour shall not exceed 400 cubic meters. This limitation helps control the heat of hydration during construction and prevents excessive thermal stress on the in-service oil and gas pipeline 2. The foamed concrete 6 completely encapsulates the in-service oil and gas pipeline 2, and the distance between the outer surface of the pouring cavity 3 and the outer surface of the in-service oil and gas pipeline 2 is greater than 20 cm. This distance requirement ensures that the foamed concrete 6 can provide a sufficient protective layer.

[0054] In the actual treatment of oil and gas pipeline defects, the deformation and defects of the in-service oil and gas pipeline 2 within the tunnel are first investigated and stress checked to identify the bulging, voiding deformation, and stress concentration areas of the in-service oil and gas pipeline 2 that need treatment. These areas are where the foamed concrete 6 is located. Then, the lateral support structure 4 is constructed at the areas to be treated. After the lateral support structure 4 is completed, the horizontal support structure 5 is installed. The installation height of the horizontal support structure 5 is 1 / 2 to 3 / 4 of the height of the lateral support structure 4. The horizontal support structure 5 is connected to the lateral support structure 4 and the lining structure 1 by bolts. After the lateral support structure 4 and the horizontal support structure 5 are completed, the foamed concrete 6 is pumped and poured segment by segment from both ends of the tunnel towards the center of the tunnel until all areas to be treated are filled with foamed concrete 6. Finally, the poured foamed concrete 6 is properly watered for curing.

[0055] In summary, this application utilizes foamed concrete for the treatment of defects in the in-service oil and gas pipeline 2. By leveraging the excellent fluidity of foamed concrete and its ease of long-distance pipeline pumping and pouring, it can adapt to the complex environment of the tunnel of the in-service oil and gas pipeline 2, ensuring uninterrupted gas supply during construction. This significantly reduces labor and treatment costs while greatly improving efficiency. The inherent strength of foamed concrete effectively secures the pipeline, reducing the risk of deformation due to temperature, transport pressure, and geological activity. The lateral support structure 4, horizontal support structure 5, lining structure 1, and segmented foamed concrete 6 form an integrated load-bearing structure, effectively limiting lateral deformation during operation and greatly reducing the risk of horizontal swaying displacement, thus ensuring the safe operation of the pipeline. The segmented foamed concrete filling structure design can target severely deformed and excessively stressed areas of pipelines within tunnels for targeted treatment and hazard mitigation. This allows for precise reinforcement of pipeline deformation and potential hazards, effectively reducing the risk of future pipeline deformation and lowering maintenance costs. On one hand, it minimizes the volume of foam filling while ensuring effective treatment, shortening the construction period and avoiding any impact on the operation of in-service pipelines. On the other hand, the segmented filling design solves the problem of high hydration heat release caused by excessive single-unit foamed concrete pouring, preventing additional thermal stress from hydration heating that could lead to further thermal expansion and deformation of the pipeline, thus ensuring safe operation.

[0056] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A segmental foamed concrete casting structure for an in-service oil and gas pipeline, characterized in that, The lining structure (1) includes a space for accommodating an in-service oil and gas pipeline (2), and the space includes a casting cavity (3) that includes at least a casting inlet and a pipeline inlet and outlet. The in-service oil and gas pipeline (2) passes through the pipeline inlet and outlet.

2. The segmental foamed concrete casting structure for an in-service oil and gas pipeline according to claim 1, characterized in that, Also includes: The lateral support structure (4) installed in the placement space is used to form the casting cavity (3) with the inner wall of the lining structure (1).

3. The segmental foamed concrete casting structure for an in-service oil and gas pipeline according to claim 2, characterized in that, One lateral support structure (4) is provided, and the lateral support structure (4) together with the side inner wall structure, bottom inner wall structure, front inner wall structure and back inner wall structure of the lining structure (1) constitute the casting cavity (3).

4. The segmental foamed concrete casting structure for an in-service oil and gas pipeline according to claim 3, characterized in that, The lateral support structure (4) is a cast-in-place or precast reinforced concrete slab, and the thickness of the lateral support structure (4) is greater than 15cm.

5. A segmental foamed concrete casting structure for an in-service oil and gas pipeline according to claim 4, characterized in that, Also includes: The horizontal support structure (5) installed in the placement space has one end connected to the lateral support structure (4) for supporting the lateral support structure (4), and the other end connected to the inner wall of the lining structure (1).

6. A segmental foamed concrete casting structure for an in-service oil and gas pipeline according to claim 5, characterized in that, The installation height of the horizontal support structure (5) is 1 / 2 to 3 / 4 of the height of the lateral support structure (4).

7. A segmental foamed concrete casting structure for an in-service oil and gas pipeline according to claim 6, characterized in that, The horizontal support structure (5) is one or more of the following: I-beams, steel pipes, angle steel, and square steel.

8. The segmental foamed concrete casting structure for an in-service oil and gas pipeline according to claim 1, characterized in that, The top of the lining structure (1) is an outwardly convex arch structure.

9. A segmental foamed concrete filling structure for an in-service oil and gas pipeline, comprising at least two segmental foamed concrete casting structures for in-service oil and gas pipelines as described in claim 1, characterized in that, Also includes: Foamed concrete (6) is poured into the pouring cavity (3) through the pouring port, and the foamed concrete (6) is used to fix the in-service oil and gas pipeline (2).

10. A segmental foamed concrete filling structure for an in-service oil and gas pipeline according to claim 9, characterized in that, At least two foamed concrete (6) are provided, and the distance between two adjacent foamed concrete (6) is 20m to 60m; The distance between the outer surface of the casting cavity (3) and the outer surface of the in-service oil and gas pipeline (2) is greater than 20cm.

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