Performance of Diamond like carbon coating against simulated inorganic carbonate scale deposition

The formation of scales, particularly carbonates, is detrimental to flow assurance and may be managed with an effective surface coating. This work investigates the potential of several coatings (e.g. diamond-like carbon, or DLC, polymer, and metallic) against carbonate scale under static and dynamic test conditions carried out in pressurized autoclave using carbonate scaling brine. Using various controlled methods and tests, coating micro-hardness, friction coefficient under different contact stresses, contact angles, and surface energies, wear rate has been measured. Surface and cross-section characteristics of the coatings were analyzed using XPS, Raman spectroscopy, SEM and EDS to examine microstructures compositions. The characterization analysis revealed multiple correlations between the surface properties and surface-scale affinity. It was established that DLCs of various types offer excellent performance against scales. The polymer coatings are also confirmed to be effective, while metallic coatings underperformed.