A near-wall enrichment type anti-blocking coating structure for hydrate slurry pipeline and a construction method thereof

Abstract

The application discloses a near-wall enrichment type anti-blocking coating structure for a hydrate slurry pipeline and a construction method, which comprises a substrate bonding layer, a low surface energy regulation layer, a biomimetic micro-nano structure layer and an inhibitor interaction functional layer arranged outward from the inner wall of the pipeline base body in sequence; the inhibitor interaction functional layer comprises functional sites capable of interacting with inhibitor molecules, and a blocking prevention reinforcement domain is formed by enhancing the residence and directional distribution of inhibitor molecules in the near-wall region. The application realizes near-wall inhibitor enrichment, cooperatively improves the anti-attachment, anti-deposition and slip promotion capabilities, and effectively solves the near-wall blocking problem of the key pipeline section.

Description

Technical Field

[0001] This invention relates to the field of anti-clogging technology for hydrate-containing slurry pipelines, and in particular to a near-wall enrichment type anti-clogging coating structure and construction method for hydrate-containing slurry pipelines. Background Technology

[0002] In deep-water oil and gas mixed transportation, natural gas gathering and transportation, cryogenic high-pressure pipeline transportation, and water-rich multiphase flow transportation scenarios, hydrate blockage remains one of the key issues threatening operational safety and continuous production. For the special flow system of hydrate-containing slurry, blockage formation is not a simple process of cross-sectional reduction, but a multi-stage evolutionary process that includes particle generation, agglomeration, near-wall retention, initial attachment, deposition growth, and bridging blockage.

[0003] In the aforementioned evolutionary process, the region most prone to and first experiencing structural changes is often not the mainstream core area, but rather the boundary layer region near the pipe wall. This region has a large velocity gradient, a significant temperature boundary effect, a longer particle residence time, and more direct physical and chemical interactions between particles and the wall surface. Therefore, it often becomes the initial region for blockage initiation.

[0004] Existing anti-fouling technologies can be broadly categorized into bulk chemical approaches and interface control approaches. Bulk chemical approaches typically use thermodynamic inhibitors, kinetic inhibitors, or anti-agglomeration agents to alter hydrate formation conditions, crystal growth rates, or interparticle interactions, thereby reducing the risk of particle agglomeration and densification. Interface control approaches typically reduce the initial adhesion probability of hydrate particles to the pipe wall surface by altering the surface free energy, surface roughness, wettability, or microstructural characteristics.

[0005] However, relying solely on bulk agents is often insufficient to solve near-wall blockage problems. Although inhibitors exist dispersed throughout the overall volume, their effective local concentration in the near-wall region may not be stable. Affected by boundary layer transport, local shear, and interfacial interactions, problems such as insufficient supply, short residence time, or decreased local efficacy may occur.

[0006] Conversely, relying solely on low surface energy coatings or ordinary biomimetic interfaces based on interface control may not be sufficient. If a large number of structured aggregates or highly viscous particle groups still exist in the slurry liquid phase, these particles may still form stable accumulations in local stagnant zones or temperature drop zones, and simple anti-adhesion surfaces cannot fundamentally prevent the evolution of blockage.

[0007] Therefore, there is an urgent need to design a coating that combines the advantages of bulk agents and interface-modulating agents. This coating can not only reduce surface free energy, but also regulate the residence, adsorption, resupply, and directional distribution of inhibitors in the near-wall region through micro-nano structures, chemical functional sites, or local interface energy distribution. It is not limited to simple anti-adhesion materials, but serves as a near-wall inhibitor organization platform. Summary of the Invention

[0008] The purpose of this invention is to provide a near-wall enrichment-type anti-clogging coating structure and construction method for pipelines containing hydrate slurries. Through a multi-layered synergistic design of a substrate bonding layer, a low surface energy regulation layer, a biomimetic micro / nano structure layer, and an inhibitor interaction functional layer, the inhibitor forms a stable and continuously renewable near-wall enrichment layer near the pipe wall, further forming an anti-clogging enhancement domain. This invention is applicable to deep-water oil and gas mixed transportation, natural gas gathering and transportation, cryogenic high-pressure pipeline transportation, and water-rich multiphase flow transportation scenarios, and is particularly suitable for critical pipe sections prone to hydrate deposition and clogging, such as elbows, before and after valves, and local temperature drop zones.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] This invention provides a near-wall enrichment-type anti-clogging coating structure for pipelines containing hydrated slurries. The structure is disposed on the inner wall of a pipeline substrate transporting the hydrated slurry. From the inner wall of the pipeline substrate outwards, the anti-clogging coating structure comprises: a substrate bonding layer configured to enhance the adhesion strength between the anti-clogging coating structure and the pipeline substrate; a low surface energy regulation layer disposed on the side of the substrate bonding layer away from the pipeline substrate, configured to reduce surface free energy; a biomimetic micro / nano structure layer disposed on the side of the low surface energy regulation layer away from the substrate bonding layer, configured to change the near-wall fluid streamline distribution and reduce the actual contact area; and an inhibitor interaction functional layer disposed on the side of the biomimetic micro / nano structure layer away from the low surface energy regulation layer, containing functional sites capable of interacting with inhibitor molecules. The inhibitor interaction functional layer is configured to enhance the residence and directional distribution of inhibitor molecules in the near-wall region through these functional sites, thereby forming an anti-clogging reinforcement domain on the surface of the anti-clogging coating structure.

[0011] In one embodiment, the substrate bonding layer is at least one of a primer layer, a coupling layer, a plasma-activated layer, a chemically grafted layer, or an interlocking layer formed by roughening pretreatment.

[0012] In one embodiment, the low surface energy control layer comprises at least one of fluorine-containing groups, silicon-containing groups, or long-chain hydrophobic groups; the biomimetic micro / nano structure layer comprises multi-scale micro / nano structures configured to reduce the actual contact area between hydrate particles and the anti-clogging coating structure and enhance particle slip behavior.

[0013] In one implementation, the multi-scale micro / nano structure is a multi-scale micro / nano protrusion structure or a multi-scale micro / nano groove structure that simulates the surface of lotus leaves, fish scales, shark skin, or insect wings.

[0014] In one implementation, the functional site is configured to interact with the inhibitor molecule through at least one of hydrogen bonding, electrostatic interaction, polar interaction, hydrophobic association, or pore confinement.

[0015] In one implementation, the functional sites are introduced onto the surface of the biomimetic micro / nano structure layer via chemical grafting, and the functional sites are configured to reversibly interact with inhibitor molecules to achieve continuous renewal and replenishment of inhibitor molecules.

[0016] As one implementation method, the anti-clogging coating structure is implemented in at least one of the following forms: layered structure, alternating composite structure, gradient composite structure, or local area composite structure.

[0017] Furthermore, this invention also provides a method for constructing a near-wall enrichment-type anti-clogging coating for hydrate-containing slurry pipelines, for constructing the anti-clogging coating structure as described above, comprising: performing cleaning, degreasing, roughening, and surface activation treatment on the inner wall of the pipeline substrate; applying a substrate bonding layer to the inner wall of the pipeline substrate and performing a curing treatment; forming a low surface energy regulation layer on the side of the substrate bonding layer away from the pipeline substrate; constructing a biomimetic micro / nano structure layer on the surface of the low surface energy regulation layer; introducing functional sites that interact with inhibitor molecules on the surface of the biomimetic micro / nano structure layer to form an inhibitor interaction functional layer; and performing crosslinking, curing, and stabilization treatment on the composite structure comprising the substrate bonding layer, the low surface energy regulation layer, the biomimetic micro / nano structure layer, and the inhibitor interaction functional layer to obtain the anti-clogging coating structure.

[0018] As one implementation method, the construction of a biomimetic micro / nano structure layer on the surface of the low surface energy regulation layer includes: constructing a multi-scale micro / nano structure on the surface of the low surface energy regulation layer using template imprinting, laser etching, or micro / nano replication; the introduction of functional sites that interact with inhibitor molecules on the surface of the biomimetic micro / nano structure layer includes: introducing functional sites that can reversibly interact with inhibitor molecules on the surface of the multi-scale micro / nano structure using chemical grafting.

[0019] Furthermore, the present invention also provides a pipeline system for transporting hydrate-containing slurry, comprising a pipeline body, the pipeline body including a high-risk pipe section and a normal straight pipe section; the high-risk pipe section includes at least one of an elbow section, a pre-valve section or a post-valve section, and the inner wall of the high-risk pipe section is provided with an anti-clogging coating structure as described above; the inner wall of the normal straight pipe section is not provided with the anti-clogging coating structure or is only provided with an anti-corrosion coating.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] 1. "Near-wall inhibitor enrichment" is explicitly defined as the coating structure design goal, rather than simply forming a normal anti-adhesion surface.

[0022] 2. Simultaneously, by utilizing substrate bonding, low surface energy regulation, biomimetic micro / nano structures, and functional site design, a multi-layered synergistic anti-blocking mechanism is formed.

[0023] 3. Without significantly increasing the total amount of chemical injected, prioritize strengthening the near-wall area most prone to clogging.

[0024] 4. It can simultaneously achieve four types of effects: reducing adhesion, reducing deposition, increasing slip, and increasing resuspension.

[0025] 5. Suitable for local reinforcement applications in critical high-risk pipe sections such as elbows, before and after valves, and areas with localized temperature drop.

[0026] 6. It has a clear structural composition and an implementable construction process, which facilitates engineering promotion.

[0027] 7. Structural parameters can be optimized based on pipeline material, particle size, inhibitor type, and operating condition window. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the multi-layer coating structure.

[0029] Figure 2 To construct the method flowchart.

[0030] Figure 3 This is a schematic diagram of the localized coating application on a critical pipe section. Detailed Implementation

[0031] The technical solution of the present invention will be further described below with reference to specific embodiments and accompanying drawings, but the present invention is not limited to specific embodiments.

[0032] Example 1

[0033] like Figure 1 As shown, this embodiment provides a near-wall enrichment-type anti-clogging coating structure for pipelines containing hydrated slurries, which is disposed on the inner wall of the pipeline substrate transporting the hydrated slurry. The anti-clogging coating structure includes, from the inner wall of the pipeline substrate outward, a substrate bonding layer, a low surface energy regulation layer, a biomimetic micro / nano structure layer, and an inhibitor interaction functional layer.

[0034] The substrate bonding layer is configured to enhance the adhesion strength between the anti-clogging coating structure and the pipe substrate. Through physical interlocking, chemical bonding, or van der Waals forces, it firmly locks the outer functional structure onto the pipe substrate, preventing the coating from peeling or failing under long-term shear stress, thereby providing a reliable carrier support for the stable performance of the upper functional layer. As one embodiment, the substrate bonding layer is at least one of a primer layer, coupling layer, plasma-activated layer, chemically grafted layer, or an interlocking layer formed by roughening pretreatment.

[0035] Specifically, when the pipe substrate is carbon steel, a primer layer, such as an epoxy zinc-rich primer or a phenolic epoxy primer, is preferred as the substrate bonding layer. When the pipe substrate is stainless steel or glass fiber reinforced plastic composite pipe, due to its surface chemical inertness or high smoothness, physical adhesion alone is often insufficient to meet the requirements of high-pressure erosion. In this case, a coupling layer, such as a silane coupling agent treatment layer containing amino, epoxy, or vinyl functional groups, is preferred as the substrate bonding layer. One end of the coupling agent molecule reacts with the hydroxyl groups or active sites on the surface of the pipe substrate, while the other end forms a chemical bond with the upper low surface energy regulating layer or biomimetic micro / nano structure layer, thereby constructing a strong molecular bridge between the inorganic or organic substrate and the organic coating. For certain special polymer material pipes or substrates with extremely inert surfaces, a plasma activation layer can also be used as the substrate bonding layer. Polar groups are introduced through oxygen plasma or argon plasma bombardment, increasing surface energy and improving wettability, laying the foundation for the uniform spread of subsequent coatings. In addition, under harsh conditions such as extremely high flow rates or high sand content, the substrate bonding layer can also be an interlocking layer formed by roughening pretreatment such as sandblasting, laser etching or acid etching, which greatly improves the shear strength of the coating by utilizing the micron-level mechanical interlocking effect.

[0036] The low surface energy control layer is disposed on the side of the substrate bonding layer away from the pipe matrix. It is configured to reduce surface free energy and, by constructing a low-energy interface, significantly reduce the adhesion work between hydrate particles and the wall surface, thereby increasing the energy barrier for particle adhesion. As one embodiment, the low surface energy control layer contains at least one of fluorine-containing groups, silicon-containing groups, or long-chain hydrophobic groups.

[0037] Specifically, fluorinated groups can be selected from perfluoropolyethers, perfluoroalkyl acrylates, or fluorinated polyurethanes, etc. These groups can significantly weaken the van der Waals forces and hydrogen bonds between hydrate particles and the wall surface thermodynamically. Silicon-containing groups can be selected from polydimethylsiloxanes, amino-modified silicone oils, or epoxy-modified silicone resins, etc., which can form a molecular brush effect at the interface, hindering particle anchoring. Long-chain hydrophobic groups can be selected from straight-chain or branched alkyl groups such as octadecyl, hexadecyl, or dodecyl, which form a hydrophobic barrier through dense arrangement.

[0038] A biomimetic micro / nanostructure layer is disposed on the side of the low surface energy control layer away from the substrate bonding layer. It is configured to alter the near-wall fluid streamline distribution and reduce the actual contact area, introducing a microscale geometric morphology control mechanism. On one hand, the micro / nanostructure can induce local vortices or slip effects in the near-wall fluid, reducing the residence time of particles in the stagnant region. On the other hand, when particles contact the wall surface, the micro / nano protrusions or grooves transform the solid-solid contact from a continuous surface contact to discrete point or line contact, significantly reducing the actual contact area. As one implementation, the biomimetic micro / nanostructure layer includes multi-scale micro / nanostructures configured to reduce the actual contact area between hydrate particles and the anti-clogging coating structure and enhance particle slip behavior.

[0039] Furthermore, as a preferred embodiment, the multi-scale micro / nano structure is a multi-scale micro / nano protrusion structure or a multi-scale micro / nano groove structure that simulates the surface of lotus leaves, fish scales, shark skin, or insect wings. For example, when using a micro / nano protrusion structure that simulates the surface of a lotus leaf, randomly distributed or ordered micron-sized papillae can be constructed on the coating surface, and nano-sized waxy crystal-like protrusions can be superimposed on the surface of the papillae. When using a micro / nano groove structure that simulates the surface of shark skin, ridge-like grooves arranged along the flow direction can be constructed on the coating surface. In addition, the imbricated structure that simulates the surface of fish scales or the columnar array structure that simulates the surface of insect wings are also feasible alternatives, as long as they have multi-scale characteristics and can achieve the functions of reducing contact and increasing slip.

[0040] The inhibitor interaction functional layer is disposed on the side of the biomimetic micro / nanostructure layer away from the low surface energy control layer, and contains functional sites capable of interacting with inhibitor molecules. These functional sites can be specific chemical groups, charge centers, or topological pores, possessing specific recognition and capture capabilities for inhibitor molecules in the fluid. The inhibitor interaction functional layer is configured to enhance the residence and directional distribution of inhibitor molecules in the near-wall region through these functional sites, thereby forming an anti-blocking reinforcement domain on the surface of the anti-blocking coating structure. It should be noted that the anti-blocking reinforcement domain is not a physical solid layer of the coating itself, but rather a local functional boundary layer dynamically formed during the flow of the hydrate-containing slurry by the interaction of the aforementioned four physical structures with the fluid environment. Within this region, due to the enrichment effect of inhibitor molecules by the functional sites, the effective inhibitor concentration near the wall is significantly higher than that in the main flow field; simultaneously, combined with the physical anti-adhesion effect of the low surface energy and the micro / nanostructure, the particle slippage ability, anti-deposition ability, and rheological stability within this region are comprehensively improved. As one implementation method, the anti-blocking coating structure can be implemented using at least one of the following forms: a layered structure, an alternating composite structure, a gradient composite structure, or a localized composite structure. This feature expands the scope of protection of this application from a macroscopic structural perspective to accommodate diverse engineering application scenarios.

[0041] In one implementation, the functional site is configured to interact with the inhibitor molecule through at least one of hydrogen bonding, electrostatic interaction, polar interaction, hydrophobic association, or pore confinement. Specifically, this interaction is tailored to the chemical structure of the inhibitor molecule used in the actual delivery system. For example, when using kinetic inhibitors such as polyvinylpyrrolidone or polyvinylcaprolactam, the functional site can contain amide, hydroxyl, or carboxyl groups capable of forming hydrogen bonds. These polar groups form a multiple hydrogen bond network with the lactam ring or amine group in the inhibitor molecule, thereby achieving efficient inhibitor capture. When the system uses antipolymers or surfactant-type inhibitors containing ionic functional groups, the functional site can contain charged groups, such as quaternary ammonium cations, sulfonate anions, or phosphate groups, anchoring the inhibitor molecule to the near-wall region through electrostatic attraction. Furthermore, for some nonpolar or weakly polar inhibitors, the functional site can also utilize hydrophobic association between long-chain alkyl groups or the spatial confinement effect generated by the nanopores formed by the micro / nano structure itself to enhance retention.

[0042] Furthermore, as a preferred embodiment, functional sites are introduced onto the surface of the biomimetic micro / nanostructure layer via chemical grafting, and these sites are configured to reversibly interact with inhibitor molecules to achieve continuous renewal and replenishment of inhibitor molecules. Chemical grafting refers to attaching functional molecules to the surface of the biomimetic micro / nanostructure layer through covalent bonds. Specific grafting methods include, but are not limited to, surface-initiated atom transfer radical polymerization, silane coupling agent grafting, click chemistry reactions, or plasma-assisted grafting. For example, an initiator with double bonds or active halogens can be modified onto the surface of the biomimetic micro / nanostructure layer first, and then polymerized in situ to generate a polymer brush containing functional groups; or coupling agents such as aminosilanes and epoxysilanes can be used as bridges to chemically bond functional molecules to the surface of the micro / nanostructure.

[0043] More importantly, the interaction between functional sites and inhibitor molecules is reversible: when inhibitor molecules diffuse from the mainstream region to the near-wall region, the functional sites capture them, increasing the local concentration; when the inhibitor concentration in the near-wall region reaches saturation or under the action of fluid shear force, some of the captured inhibitor molecules will dissociate from the functional sites and re-enter the fluid boundary layer to participate in inhibiting the growth or aggregation of hydrate particles. At the same time, newly flowing inhibitor molecules continuously replenish the vacated functional sites, forming a dynamic circulation mechanism, ensuring that the inhibitors in the anti-blocking enhancement domain are always in an active state, avoiding the problem of rapid failure of traditional immobilized coatings due to irreversible occupation of active sites.

[0044] As one implementation method, the anti-fouling coating structure is achieved using at least one of the following forms: a layered structure, an alternating composite structure, a gradient composite structure, or a localized composite structure. Among these, a layered structure refers to... Figure 1The standard four-layer stacked configuration shown is easy to control in terms of quality and suitable for most conventional conveying conditions. Alternating composite structures refer to the multiple alternating deposition of low surface energy control layers and biomimetic micro / nano structure layers along the thickness direction, forming a multilayer film-like structure. This structure not only increases the number of interlayer interfaces to dissipate crack propagation energy and improve the mechanical durability of the coating, but also further optimizes the physical anti-adhesion properties of the near-wall region through light scattering or flow field modulation effects at the multilayer interfaces. Gradient composite structures refer to a continuous or stepwise change in the content or properties of functional components along the coating thickness direction. For example, the concentration of functional sites in the inhibitor interaction functional layer gradually increases from the inside to the outside, or low surface energy components gradually accumulate from the inside to the outside. This gradient design can effectively alleviate interfacial stress concentration caused by differences in the thermal expansion coefficients or moduli of the materials in each layer, reducing the risk of coating cracking, while making the formation of the anti-blocking reinforcement domain more smoothly transitioned, avoiding fluid disturbances caused by sudden changes in local concentration. The localized composite structure, based on the varying wear or blockage risks in different areas of the pipe's inner wall, applies a complete four-layer anti-clogging coating only to specific high-risk areas, while reducing the coating thickness or the number of functional layers in low-risk areas. This non-uniform structural layout significantly reduces material costs and construction time while ensuring effective protection for critical components.

[0045] Example 2

[0046] This embodiment also provides a method for constructing a near-wall enrichment-type anti-clogging coating for pipelines containing hydrate slurries, used to construct the anti-clogging coating structure as described in Example 1, such as... Figure 2 As shown, it includes the following steps:

[0047] S100 involves cleaning, degreasing, roughening, and surface activation treatment of the inner wall of the pipe substrate. Cleaning and degreasing aim to thoroughly remove residual grease, rust, and other organic contaminants from the inner wall of the pipe. Roughening can be performed through sandblasting, acid etching, or mechanical grinding to create a micron-level rough morphology on the pipe substrate surface, providing mechanical interlocking sites for the subsequent substrate bonding layer. Surface activation typically employs plasma bombardment or chemical oxidation immersion to generate active functional groups such as hydroxyl and carboxyl groups in situ on the metal or composite material surface, enhancing the interfacial bonding energy between the coating and the substrate.

[0048] S200 involves applying a base bonding layer to the inner wall of the pipe substrate and then performing a curing process. On the pre-treated surface, a primer, coupling agent, or other bonding material is uniformly applied by spraying, dipping, or brushing. The curing process can be heat curing, UV curing, or room temperature air drying, depending on the chemical system of the selected materials.

[0049] S300 involves forming a low surface energy control layer on the side of the substrate bonding layer facing away from the channel matrix. This step typically involves coating and drying a functional resin solution containing fluorine, silicon, or long-chain alkyl groups. Strict control of the solvent evaporation rate and film formation temperature is required to ensure optimal enrichment and orientation of the low surface energy groups, providing a uniform chemical substrate for the subsequent construction of micro / nano structures.

[0050] S400 constructs biomimetic micro / nano structures on the surface of a low surface energy control layer, including multi-scale micro / nano structures using stencil imprinting, laser etching, or micro / nano replication. For example, when using stencil imprinting, a PDMS soft stencil or a nickel hard stencil with a pre-set micro / nano pattern can be used. Imprinting is performed while the resin is in a semi-cured or thermoplastic state, and after demolding, the corresponding array of protrusions or grooves can be replicated on the coating surface. When using laser etching, femtosecond or picosecond ultrafast lasers can be used to precisely ablate the coating surface. The micro / nano replication method is suitable for mass production, achieving structure transfer by replicating a pre-made micro / nano master onto the coating surface.

[0051] S500 introduces functional sites that interact with inhibitor molecules onto the surface of a biomimetic micro / nanostructure layer to form an inhibitor-interacting functional layer. Specifically, this involves using chemical grafting to introduce functional sites capable of reversible interactions with inhibitor molecules onto the surface of multi-scale micro / nanostructures. In practice, segments of the constructed micro / nanostructure can be immersed in a reaction solution containing functional monomers, initiators, and catalysts, or initiators can be pre-modified onto the micro / nanostructure surface before monomer vapor is introduced for gas-phase grafting. This chemical grafting method ensures the strength of the covalent bonds between the functional sites and the micro / nanostructure, making them less prone to detachment under long-term fluid erosion. Simultaneously, by selecting specific functional monomers (such as monomers containing amide groups, quaternary ammonium salts, or sulfonic acid groups), the grafted layer is endowed with the ability to engage in reversible interactions with inhibitor molecules, such as hydrogen bonding, electrostatic interaction, or hydrophobic association, thereby achieving the dynamic capture and release of inhibitors.

[0052] S600 involves crosslinking, curing, and stabilizing a composite structure comprising a substrate bonding layer, a low surface energy regulation layer, a biomimetic micro / nanostructure layer, and an inhibitor interaction functional layer to obtain an anti-clogging coating structure. This step aims to further improve the overall density and environmental aging resistance of the coating.

[0053] Example 3

[0054] like Figure 3 As shown, this embodiment provides a pipeline system for transporting hydrate-containing slurry, achieving a balance between anti-clogging performance and engineering economy through a differentiated coating layout strategy. The pipeline system includes a main pipeline body, which comprises high-risk pipe sections and ordinary straight pipe sections.

[0055] Specifically, high-risk pipe sections include at least one of elbow sections, pre-valve sections, or post-valve sections, and the inner walls of these high-risk pipe sections are provided with an anti-clogging coating structure as described in Example 1. During the transportation of hydrate-containing slurry, the flow field in these pipe sections is extremely complex due to abrupt changes in geometry or the presence of throttling elements, making it easy for particles to accumulate on the wall surface. Therefore, a complete anti-clogging coating structure comprising a substrate bonding layer, a low surface energy regulation layer, a biomimetic micro / nano structure layer, and an inhibitor interaction functional layer is provided on the inner walls of these high-risk pipe sections. This utilizes the synergistic mechanism of near-wall inhibitor accumulation and physical anti-adhesion in the anti-clogging reinforcement domain to prevent the initiation of clogging at critical locations.

[0056] In contrast, the inner walls of ordinary straight pipe sections lack anti-clogging coating structures or only have anti-corrosion coatings. In straight pipe sections far from fittings and valves, stable adhesion and deposit buildup are less likely to form. For such low-risk areas, laying high-performance anti-clogging coatings along the entire length would not only result in excessive waste of materials and construction costs but may also introduce unnecessary maintenance burdens due to the large coating area. Therefore, retaining only a basic anti-corrosion coating or even without special treatment in ordinary straight pipe sections meets the basic corrosion resistance requirements of the pipeline while significantly reducing the overall project cost.

[0057] Example 4

[0058] This embodiment designed four sets of comparative samples for anti-clogging performance testing, aiming to demonstrate through comparative examples with structural deficiencies that relying solely on single or partial physical anti-adhesion methods cannot solve the near-wall clogging problem.

[0059] The four sets of comparative samples were set up as follows: the first set was an untreated carbon steel inner wall as a blank control; the second set only had a low surface energy control layer on the inner wall of the pipe substrate; the third set had a biomimetic micro / nano structure layer superimposed on the low surface energy control layer; and the fourth set used a complete four-layer anti-clogging coating structure, that is, an inhibitor interaction functional layer was further introduced on the basis of the third set. All samples were tested under the same hydrate slurry ratio, the same inhibitor molecule concentration, the same flow rate, and the same temperature and pressure conditions to ensure the objectivity and accuracy of the comparative results. Four key evaluation indicators were selected for the test: near-wall deposition rate, particle adhesion quantity, slip critical shear stress, and near-wall effective protection time, which comprehensively characterized the anti-clogging performance from four dimensions: deposition kinetics, interface adhesion state, particle removal difficulty, and protection durability.

[0060] Test results show that the performance of each group of samples exhibits a significant stepwise difference. For the first group of untreated steel walls, due to the high surface energy and lack of flow field regulation, hydrate particles easily undergo initial adhesion and rapid growth in the near-wall region, resulting in the highest near-wall deposition rate, the largest number of adhered particles, the highest slip critical shear stress, and the shortest effective protection time. After introducing a low surface energy regulation layer, the second group improved all the above indicators by reducing the interfacial free energy and increasing the adhesion energy barrier. However, in local stagnant regions or under high subcooling conditions, the low-energy surface alone is still insufficient to completely prevent the stable accumulation of structured aggregates, and the near-wall deposition rate remains at a high level. The third group, based on this, adds a biomimetic micro / nano structure layer, using multi-scale structures to change the near-wall streamline distribution and reduce the actual contact area, resulting in a further significant decrease in the number of adhered particles and the deposition rate, as well as a significant reduction in the slip critical shear stress, demonstrating the effectiveness of the physical anti-adhesion mechanism. However, even in the third group, as the running time increased, the concentration of inhibitor molecules in the near-wall region decreased due to boundary layer transport limitations, resulting in a gradual decline in the anti-blocking effect over time, and the effective protection time near the wall still did not reach the ideal level.

[0061] In summary, the comparative experimental results demonstrate that the lack of a substrate bonding layer leads to coating failure under high-pressure erosion; the lack of a low surface energy regulation layer or a biomimetic micro / nano structure layer weakens the physical anti-adhesion foundation; and the lack of an inhibitor interaction functional layer prevents the formation of an anti-clogging reinforcement domain, resulting in the inability to maintain a long-lasting high-concentration inhibitor environment in the near-wall region, ultimately hindering the achievement of a comprehensive anti-clogging effect. Therefore, only when all four physical structures are intact and work synergistically can the clogging problem in the near-wall region of hydrate-containing slurry pipelines be fundamentally solved.

[0062] The above description represents a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A near-wall enrichment-type anti-clogging coating structure for pipelines containing hydrated slurries, disposed on the inner wall of the pipeline substrate conveying the hydrated slurry, characterized in that, The anti-clogging coating structure, from the inner wall of the pipe substrate outwards, includes the following: A substrate bonding layer is configured to enhance the adhesion strength between the anti-clogging coating structure and the pipe substrate; A low surface energy control layer is disposed on the side of the substrate bonding layer away from the pipe substrate, and is configured to reduce surface free energy. A biomimetic micro / nano structure layer is disposed on the side of the low surface energy control layer away from the substrate bonding layer, and is configured to change the near-wall fluid streamline distribution and reduce the actual contact area. The inhibitor interaction functional layer is located on the side of the biomimetic micro / nano structure layer away from the low surface energy regulation layer, and contains functional sites that can interact with inhibitor molecules. The inhibitor interaction functional layer is configured to enhance the residence and directional distribution of inhibitor molecules in the near-wall region through the functional sites, so as to form an anti-blocking reinforcement domain on the surface of the anti-blocking coating structure.

2. The anti-clogging coating structure according to claim 1, characterized in that, The substrate bonding layer is at least one of the following: primer layer, coupling layer, plasma activation layer, chemical grafting layer, or interlocking layer formed by roughening pretreatment.

3. The anti-clogging coating structure according to claim 1, characterized in that, The low surface energy control layer contains at least one of fluorine-containing groups, silicon-containing groups, or long-chain hydrophobic groups; the biomimetic micro / nano structure layer contains multi-scale micro / nano structures configured to reduce the actual contact area between hydrate particles and the anti-clogging coating structure and enhance particle slip behavior.

4. The anti-clogging coating structure according to claim 3, characterized in that, The multi-scale micro-nano structure is a multi-scale micro-nano protrusion structure or a multi-scale micro-nano groove structure that simulates the surface of lotus leaves, fish scales, shark skin or insect wings.

5. The anti-clogging coating structure according to claim 1, characterized in that, The functional site is configured to interact with the inhibitor molecule through at least one of hydrogen bonding, electrostatic interaction, polar interaction, hydrophobic association, or pore confinement.

6. The anti-clogging coating structure according to claim 5, characterized in that, The functional sites are introduced onto the surface of the biomimetic micro / nano structure layer through chemical grafting, and the functional sites are configured to interact reversibly with inhibitor molecules to achieve continuous renewal and replenishment of inhibitor molecules.

7. The anti-clogging coating structure according to claim 1, characterized in that, The anti-clogging coating structure is implemented in at least one of the following forms: layered structure, alternating composite structure, gradient composite structure, or local area composite structure.

8. A method for constructing a near-wall enrichment-type anti-clogging coating for hydrate-containing slurry pipelines, used to construct the anti-clogging coating structure as described in any one of claims 1-7, characterized in that, include: The inner wall of the pipe substrate is cleaned, degreased, roughened, and surface activated. Apply a base bonding layer to the inner wall of the pipe substrate and perform a curing process; A low surface energy regulation layer is formed on the side of the substrate bonding layer that is away from the pipe matrix; Constructing a biomimetic micro / nano structure layer on the surface of a low surface energy modulation layer; Functional sites that interact with inhibitor molecules are introduced on the surface of the biomimetic micro / nano structure layer to form an inhibitor-interacting functional layer; Crosslinking, curing, and stabilization processes were performed on a composite structure comprising a substrate bonding layer, a low surface energy regulation layer, a biomimetic micro / nano structure layer, and an inhibitor interaction functional layer to obtain an anti-clogging coating structure.

9. The method for constructing an anti-clogging coating according to claim 8, characterized in that, The construction of a biomimetic micro / nano structure layer on the surface of the low surface energy regulation layer includes: constructing a multi-scale micro / nano structure on the surface of the low surface energy regulation layer using template imprinting, laser etching, or micro / nano replication; the introduction of functional sites that interact with inhibitor molecules on the surface of the biomimetic micro / nano structure layer includes: introducing functional sites that can reversibly interact with inhibitor molecules on the surface of the multi-scale micro / nano structure using chemical grafting.

10. A pipeline system for transporting hydrate-containing slurry, characterized in that, The system includes a pipeline body, which comprises a high-risk pipe section and a regular straight pipe section. The high-risk pipe section includes at least one of an elbow section, a pre-valve section, or a post-valve section. The inner wall of the high-risk pipe section is provided with an anti-clogging coating structure as described in the above scheme. The inner wall of the regular straight pipe section is not provided with the anti-clogging coating structure or is only provided with an anti-corrosion coating.

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