Influence of CO₂ at HPHT Conditions on the Properties and Failures of an Amine-Cured Epoxy Novolac Coating

Using a three-phase batch reactor with coated steel panels, this investigation studies the influence of carbon dioxide (CO2), present in gas phase at conditions high pressure and temperature (HPHT), on degradation an amine-cured epoxy novolac (EN) coating. The combined effect gas, hydrocarbon, seawater compromises coating leads to underfilm corrosion. Consequently, understanding role each phases is essential for effective design superior epoxy-based coatings HPHT applications petroleum other industries. Upon exposure three individually, low N2, EN network remained unaffected impervious. However, hydrocarbon-exposed zone, combination para-xylene, representing hydrocarbon phase, CO2 initiated glass-transition depression subsequent softening network. This allowed dissolved diffuse into network, thereby generating pinholes surface. seawater-exposed presence HPHT, suffered from increased ion diffusion, leading blister formation. Moreover, most detrimental subzone was when CO2, were synergistically interacting its hydrocarbon–seawater interface. resulted chain motion subsequently allowing ions substrate, imposing In absence blisters formed interface subzone, but no corrosion detected. results are relevance industry also protection transport pipelines process equipment next-generation capture storage technologies.