A submarine multi-layer oil and gas transmission pipeline

Abstract

The present invention discloses a submarine multi-layer oil and gas transmission pipeline, comprising a pipeline body and a pipeline assembly, wherein the pipeline body is assembled through the pipeline assembly, and the pipeline assembly comprises a concrete counterweight layer, a corrugated pressure-resistant layer, an anti-corrosion protective layer, a steel pipe layer, a friction-reducing coating and spiral fins. The outer side of the pipeline body is welded with a concrete counterweight layer, the inner side of the concrete counterweight layer is provided with a corrugated pressure-resistant layer, the inner side of the corrugated pressure-resistant layer is provided with an anti-corrosion protective layer, the inner side of the anti-corrosion protective layer is plugged and installed with a steel pipe layer, the inner side of the steel pipe layer is coated with a friction-reducing coating, and the outer side of the concrete counterweight layer is provided with multiple groups of spiral fins; the composite structure of the present invention significantly improves the impact resistance and deformation adaptability of the pipeline under deep-sea high pressure, ocean current impact and geological displacement through multi-level collaborative design, and the coupling of the honeycomb skeleton and the corrugated layer not only enhances the structural stability, but also reduces material redundancy and construction costs.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas transportation, and in particular to a submarine multi-layer oil and gas transportation pipeline. Background Art

[0002] As the core facility for deep-sea resource development, the performance of submarine oil and gas pipelines directly determines the safety and economy of oil and gas transportation. Traditional pipelines mostly adopt single or simple multi-layer structures, but they face significant technical bottlenecks in complex deep-sea environments and lack compressive and deformation adaptability. Although conventional concrete counterweight layers can provide stability through their own weight, their rigid structure is prone to stress concentration under the impact of ocean currents or geological displacement, leading to pipeline fracture or plastic deformation failure. The contradiction between structural redundancy and cost is prominent. Existing technologies often increase the thickness of steel pipes or add external reinforcement structures to improve compressive resistance. However, this not only significantly increases material costs, but also increases construction complexity, making it difficult to meet the efficient requirements of long-distance deep-sea laying. There are limitations in anti-corrosion and anti-friction performance. Traditional anti-corrosion coatings are insufficiently resistant to corrosion and are prone to localized peeling due to long-term erosion by seawater. The poor anti-friction performance of the pipeline inner wall increases the resistance to crude oil transportation and significantly increases pumping energy consumption.

[0003] Chinese Patent 202420695847.5 lacks thermodynamically coordinated design. Although some composite pipelines introduce heating layers to solve the problem of crude oil fluidity, they fail to organically combine structural compressive strength with thermal stress dispersion, resulting in local thermal expansion causing structural deformation and even leakage risks. Therefore, the present invention proposes a submarine multi-layer oil and gas pipeline to solve the problems existing in the existing technology. Summary of the Invention

[0004] In response to the above problems, the purpose of the present invention is to propose a submarine multi-layer oil and gas pipeline. This submarine multi-layer oil and gas pipeline composite structure, through multi-level collaborative design, significantly improves the pipeline's impact resistance and deformation adaptability under deep-sea high pressure, ocean current impact and geological displacement. The coupling of the honeycomb skeleton and the corrugated layer not only enhances structural stability, but also reduces material redundancy and construction costs; the combination of anti-corrosion and anti-friction coatings extends the pipeline life and reduces maintenance costs throughout the life cycle.

[0005] To achieve the objectives of the present invention, the present invention is implemented through the following technical solutions: a submarine multi-layer oil and gas transmission pipeline, comprising a pipeline body and a pipeline assembly, the pipeline body being assembled through the pipeline assembly, the pipeline assembly comprising a concrete counterweight layer, a corrugated pressure-resistant layer, an anti-corrosion protective layer, a steel pipe layer, a wear-reducing coating and spiral fins, the outer side of the pipeline body being welded with a concrete counterweight layer, the inner side of the concrete counterweight layer being provided with a corrugated pressure-resistant layer, the inner side of the corrugated pressure-resistant layer being provided with an anti-corrosion protective layer, the inner side of the anti-corrosion protective layer being plugged and installed with a steel pipe layer, the inner side of the steel pipe layer being coated with a wear-reducing coating, the outer side of the concrete counterweight layer being provided with multiple groups of spiral fins, the concrete counterweight layer being cross-arranged and welded by spiral fins to form a quadrilateral honeycomb skeleton, the interior of the honeycomb skeleton being filled with concrete to form a composite counterweight structure, the corrugated configuration of the corrugated pressure-resistant layer being connected to the honeycomb nodes of the concrete counterweight layer through spatial coupling matching.

[0006] Further improvements are: the cross welding angle of the spiral fins is 45°-60°, the thickness of the spiral fins is 1 / 5-1 / 3 of the total thickness of the concrete counterweight layer, and the side length of adjacent honeycomb units of the spiral fins is 30mm-100mm.

[0007] A further improvement is that the ratio of the corrugation period of the corrugated pressure-resistant layer to the side length of the honeycomb unit of the concrete counterweight layer is 1:1.5-1:5, and the corrugation height is 1 / 10-1 / 6 of the side length of the honeycomb unit.

[0008] A further improvement is that a glass fiber reinforced layer is provided inside the anti-corrosion protective layer. The anti-corrosion protective layer is composed of epoxy resin-based composite materials and glass fiber reinforced layers 8 laid alternately. The thickness of the glass fiber reinforced layer is 2mm-5mm.

[0009] A further improvement is that the anti-friction coating is a polyurethane-graphene composite coating, and the surface roughness of the anti-friction coating is Ra≤0.8μm.

[0010] A further improvement is that an elastic buffer layer is provided at the coupling interface between the concrete counterweight layer and the corrugated compression-resistant layer.

[0011] A further improvement is that the thickness of the friction-reducing coating is 0.5 mm to 1.2 mm.

[0012] A further improvement is that the elastic buffer layer has a thickness of 5-10 mm and is made of chloroprene rubber.

[0013] A further improvement is that a mounting base is fixedly mounted on the bottom of the pipe body, and a plurality of groups of mounting slots are provided inside the mounting base, and the size and specifications of each group of mounting slots are the same.

[0014] The beneficial effects of the present invention are as follows: the present invention uses the mutual coordination between the concrete counterweight layer, the corrugated pressure-resistant layer, the anti-corrosion protective layer, the steel pipe layer and the wear-reducing coating, and the composite structure is designed in a multi-level collaborative manner, which significantly improves the impact resistance and deformation adaptability of the pipeline under deep-sea high pressure, ocean current impact and geological displacement. The coupling of the honeycomb skeleton and the corrugated layer not only enhances the structural stability, but also reduces material redundancy and construction costs. The combination of the anti-corrosion and wear-reducing coatings extends the life of the pipeline and reduces the maintenance cost throughout the life cycle. The introduction of the elastic buffer layer further optimizes the structural response under dynamic loads, avoids the brittle failure of traditional pipelines caused by rigid connections, and solves the problem of the difficulty in balancing pressure resistance, corrosion resistance, wear-reducing performance and economy in the existing technology, providing reliable technical support for the efficient development of deep-sea oil and gas resources, and has significant engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 This is a front view of the pipeline body of the present invention;

[0017] Figure 2 This is a schematic diagram of the interior of the pipeline body of the present invention;

[0018] Figure 3 This is a stress analysis diagram of the pipeline body of the present invention;

[0019] Figure 4 This is the pipe body strain analysis diagram of the present invention.

[0020] Figure identification: 1. Pipe body; 2. Concrete counterweight layer; 3. Corrugated pressure-resistant layer; 4. Anti-corrosion protective layer; 5. Steel pipe layer; 6. Friction-reducing coating; 7. Spiral ribs; 8. Glass fiber reinforced layer; 9. Elastic buffer layer; 10. Mounting base; 11. Mounting slot. DETAILED DESCRIPTION

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0022] In the description of the present invention, it should be noted that, unless otherwise specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0023] In document 202420695847.5, a counterweight block of reinforced concrete cast structure is set outside the pipe body, which can balance the buoyancy of seawater through the counterweight block to ensure that the submarine oil and gas pipeline is reliably positioned and fixed during the laying and operation process. Anti-slip particles are set on the outer surface of the anti-corrosion layer of the pipe body to avoid relative sliding between the counterweight block and the pipe body, so that the counterweight block and the pipe body are tightly integrated into one, achieving the purpose of improving the laying efficiency of the submarine oil and gas pipeline and extending the service life of the submarine oil and gas pipeline. However, this application has the risk of leakage. In this application, the coupling of the honeycomb skeleton and the corrugated layer not only enhances the structural stability, but also reduces material redundancy, thereby avoiding the brittle failure of traditional pipelines due to rigid connection.

[0024] according to Figure 1 、 Figure 2As shown, this embodiment provides a submarine multi-layer oil and gas transmission pipeline, including a pipeline body 1 and a pipeline assembly. The pipeline body 1 is assembled through the pipeline assembly. The pipeline assembly includes a concrete balancing weight layer 2, a corrugated pressure-resistant layer 3, an anti-corrosion protective layer 4, a steel pipe layer 5, a wear-reducing coating 6 and spiral fins 7. The outer side of the pipeline body 1 is welded with a concrete balancing weight layer 2. The setting of the concrete balancing weight layer 2 increases the weight of the pipeline, so that it has sufficient negative buoyancy in seawater, ensuring that the pipeline can be stably laid on the seabed. The inner side of the concrete balancing weight layer 2 is provided with a corrugated pressure-resistant layer 3. The setting of the corrugated pressure-resistant layer 3 increases the bending stiffness and compressive strength of the pipeline through the corrugated shape, which helps to resist external pressure and load. The inner side of the corrugated pressure-resistant layer 3 is provided with an anti-corrosion protective layer 4. The anti-corrosion protective layer 4 can effectively isolate the direct contact between seawater and the metal surface of the pipeline, and prevent electrochemical corrosion caused by salt and dissolved oxygen in seawater. The inner side of the anti-corrosion protective layer 4 is plugged and installed with The steel pipe layer 5 is a direct channel for transporting oil and gas, and has sufficient strength and sealing to withstand the pressure of the internal medium and the influence of the external environment. The inner side of the steel pipe layer 5 is coated with a friction-reducing coating 6. The friction-reducing coating 6 reduces the friction and resistance of the fluid flowing inside the pipe through its smooth surface characteristics. The outer side of the concrete counterweight layer 2 is provided with multiple groups of spiral ribs 7. The concrete counterweight layer 2 is composed of spiral ribs 7 arranged crosswise and welded to form a quadrilateral honeycomb skeleton. The interior of the honeycomb skeleton is filled with concrete to form a composite counterweight structure. The corrugated configuration of the corrugated pressure-resistant layer 3 is connected to the honeycomb nodes of the concrete counterweight layer 2 through spatial coupling matching, which not only enhances the overall compressive strength through the geometric interlocking effect, but also retains the freedom of bending deformation of the pipeline to adapt to complex terrain. The peaks and troughs of the corrugated pressure-resistant layer 3 are coupled with the nodes of the honeycomb skeleton through spatial matching to construct an efficient stress dispersion network, which evenly transmits deep-sea high pressure and impact loads to the counterweight layer to avoid local stress concentration.

[0025] The cross welding angle of the spiral fins 7 is 45°-60°, the thickness of the spiral fins 7 is 1 / 5-1 / 3 of the total thickness of the concrete counterweight layer, and the side length of adjacent honeycomb units of the spiral fins 7 is 30mm-100mm.

[0026] The ratio of the corrugation period of the corrugated compression-resistant layer 3 to the side length of the honeycomb unit of the concrete counterweight layer 2 is 1:1.5-1:5, and the corrugation height is 1 / 10-1 / 6 of the side length of the honeycomb unit.

[0027] A glass fiber reinforced layer 8 is provided inside the anti-corrosion protection layer 4. The anti-corrosion protection layer 4 is composed of epoxy resin-based composite materials and glass fiber reinforced layers 8 laid alternately. The thickness of the glass fiber reinforced layer 8 is 2 mm to 5 mm.

[0028] The anti-friction coating 6 is a polyurethane-graphene composite coating, and the surface roughness of the anti-friction coating 6 is Ra≤0.8 μm.

[0029] An elastic buffer layer 9 is provided at the coupling interface between the concrete counterweight layer 2 and the corrugated compression-resistant layer 3 .

[0030] The thickness of the anti-friction coating 6 is 0.5 mm to 1.2 mm.

[0031] The thickness of the elastic buffer layer 9 is 5-10 mm, and the material of the elastic buffer layer 9 is chloroprene rubber.

[0032] A mounting base 10 is fixedly mounted on the bottom of the pipe body 1 . A plurality of mounting slots 11 are provided inside the mounting base 10 . The sizes and specifications of each group of mounting slots 11 are the same.

[0033] When the submarine multi-layer oil and gas pipeline is in use, the pipeline comprises a concrete counterweight layer 2, a corrugated pressure-resistant layer 3, an anti-corrosion protective layer 4, a steel pipe layer 5 and a wear-reducing coating 6 from the outside to the inside. The concrete counterweight layer adopts a quadrilateral honeycomb skeleton formed by cross-welding of spiral ribs, and the interior is filled with concrete. It not only enhances the overall compressive strength through the geometric interlocking effect, but also retains the freedom of bending and deformation of the pipeline to adapt to complex terrain. The crests and troughs of the corrugated pressure-resistant layer 3 are coupled with the nodes of the honeycomb skeleton through spatial matching to construct an efficient stress dispersion network, which evenly transmits deep-sea high pressure and impact loads to the counterweight layer to avoid local stress concentration. In the concrete counterweight layer, the spiral ribs are welded at a cross angle of 45°-60°, and the thickness is 1 / 5-1 / 3 of the total thickness of the counterweight layer. The side length of the honeycomb unit is 30-100mm, taking into account both lightweight and pressure resistance requirements. The corrugation period of the corrugated pressure-resistant layer 3 is designed to be 1:1.5–1:5 to the honeycomb side length, and the corrugation height is 1 / 10–1 / 6 of the honeycomb side length to ensure uniform stress distribution. The anti-corrosion protection layer 4 is made of an epoxy resin-based composite material and a glass fiber reinforced layer, alternately laid, with a thickness of 2–5 mm, and has both long-term corrosion resistance and shear resistance. The anti-friction coating 6 is made of a polyurethane-graphene composite material with a surface roughness Ra ≤ 0.8 μm and a thickness of 0.5–1.2 mm, which significantly reduces the friction resistance of crude oil flow and reduces energy consumption. An elastic buffer layer 9 is added between the concrete counterweight layer 2 and the corrugated pressure-resistant layer. The material is chloroprene rubber or silicone rubber with a thickness of 5–10 mm. This layer can effectively absorb dynamic impact energy, avoid fatigue damage caused by interlayer stress concentration, and compensate for thermal expansion differences to improve structural durability.

[0034] To illustrate the technical effects of the present invention, please refer to Figure 3 Shown is a stress distribution cloud diagram of a submarine multi-layer oil and gas pipeline provided by an embodiment of the present invention, and Figure 4The strain distribution cloud diagram of a submarine multi-layer oil and gas transmission pipeline provided by an embodiment of the present invention is shown. In this embodiment, a complete pipeline is intercepted for deep-sea pressure testing. The seabed depth is set to 2000m and the average pressure is set to 20MPa. Through the synergistic effect of the honeycomb skeleton and the corrugated layer, the structural stability of the pipeline is significantly guaranteed, thereby improving its impact resistance and deformation adaptability in deep-sea environments. Figure 3 and Figure 4 The stress-strain distribution cloud diagram can directly show the stability of the structure. The concrete counterweight layer and the skeleton structure work together with the corrugated layer to determine the compressive resistance of the pipeline. When the pressure acts on the surface of the pipeline, the stress and strain inside the pipeline remain unchanged. Figure 3 Figure 4 It can be seen that the excessive stress is mainly concentrated in the base slot. The excessive strain caused by the thickness redundancy design of the installation slot does not affect the overall compressive performance of the pipeline. According to actual application requirements, appropriate adjustment of the slot design can effectively improve this situation.

[0035] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A submarine multilayer oil and gas pipeline, comprising a pipeline body (1) and a pipeline assembly, characterized in that: The pipeline body (1) is assembled through a pipeline assembly, and the pipeline assembly includes a concrete counterweight layer (2), a corrugated pressure-resistant layer (3), an anti-corrosion protective layer (4), a steel pipe layer (5), a friction-reducing coating (6) and spiral fins (7). The concrete counterweight layer (2) is welded on the outside of the pipeline body (1), the corrugated pressure-resistant layer (3) is provided on the inside of the concrete counterweight layer (2), the anti-corrosion protective layer (4) is provided on the inside of the corrugated pressure-resistant layer (3), the steel pipe layer (5) is installed on the inside of the anti-corrosion protective layer (4), the anti-friction coating (6) is applied on the inside of the steel pipe layer (5), and the concrete counterweight layer (2) is welded on the outside of the pipeline body (1). The layer (2) is provided with multiple groups of spiral ribs (7), the concrete counterweight layer (2) is formed by cross-arranging and welding the spiral ribs (7) to form a quadrilateral honeycomb skeleton, and the interior of the honeycomb skeleton is filled with concrete to form a composite counterweight structure, the corrugated configuration of the corrugated pressure-resistant layer (3) is connected to the honeycomb nodes of the concrete counterweight layer (2) through spatial coupling matching, the side length of adjacent honeycomb units of the spiral ribs (7) is 30mm-100mm, the ratio of the corrugation period of the corrugated pressure-resistant layer (3) to the side length of the honeycomb unit of the concrete counterweight layer (2) is 1:1.5-1:5, and the corrugation height is 1 / 10-1 / 6 of the side length of the honeycomb unit.

2. The submarine multi-layer oil and gas pipeline according to claim 1, characterized in that: The cross welding angle of the spiral ribs (7) is 45°-60°, and the thickness of the spiral ribs (7) is 1 / 5-1 / 3 of the total thickness of the concrete counterweight layer.

3. The submarine multi-layer oil and gas pipeline according to claim 1, characterized in that: A glass fiber reinforced layer (8) is provided inside the anti-corrosion protective layer (4). The anti-corrosion protective layer (4) is composed of epoxy resin-based composite materials and glass fiber reinforced layers (8) laid alternately. The thickness of the glass fiber reinforced layer (8) is 2 mm to 5 mm.

4. The submarine multi-layer oil and gas pipeline according to claim 1, characterized in that: The anti-friction coating (6) is a polyurethane-graphene composite coating, and the surface roughness of the anti-friction coating (6) is Ra≤0.8 μm.

5. The submarine multi-layer oil and gas pipeline according to claim 1, characterized in that: An elastic buffer layer (9) is provided at the coupling interface between the concrete counterweight layer (2) and the corrugated pressure-resistant layer (3).

6. The submarine multi-layer oil and gas pipeline according to claim 1, characterized in that: The thickness of the anti-friction coating (6) is 0.5 mm to 1.2 mm.

7. The submarine multi-layer oil and gas pipeline according to claim 5, characterized in that: The elastic buffer layer (9) has a thickness of 5-10 mm, and the material of the elastic buffer layer (9) is chloroprene rubber.

8. The submarine multi-layer oil and gas pipeline according to claim 1, characterized in that: A mounting base (10) is fixedly mounted on the bottom of the pipe body (1), and a plurality of groups of mounting slots (11) are provided inside the mounting base (10), and the size and specifications of each group of mounting slots (11) are the same.

Images