Non-Stick Behavior of Diamond-Like Carbon and Polymer-based Coatings against Asphaltene and Petroleum Wax Deposits

Abstract Crude oil production and transport are frequently hindered by flow assurance challenges arising from asphaltene and wax deposition. These high-molecular-weight compounds precipitate due to changes in pressure, temperature, and fluid composition, forming solid deposits that obstruct pipelines and subsurface equipment, reduce throughput, and increase maintenance demands. Asphaltenes adhere strongly to metal surfaces, making mechanical removal difficult, while paraffinic waxes crystallize at low temperatures, compounding flow restrictions. This study investigates advanced surface coatings as a sustainable strategy to mitigate organic deposition. Diamond-like carbon (DLC), polymer-like carbon (PLC), and fluoropolymer-based coatings were evaluated for their ability to lower surface energy and friction, thereby reducing the tendency for organic materials to stick. Coated and uncoated substrates were subjected to controlled asphaltene and wax exposure, with non-stick performance assessed through simple pull-off tests and deposit characterization. Results revealed that certain coatings, particularly PTFE-containing polymers, exhibited superior anti-fouling behavior, with performance correlating to hydrophobicity and low friction coefficients. All PLC and DLC coatings showed reduced deposition rates compared to uncoated surfaces, with effects more pronounced for asphaltene than wax, and some variants outperforming others. These findings highlight the potential of engineered surfaces to enhance flow assurance, extend equipment life, and reduce operational costs.