Assessment of internal corrosion risk in wet sour gas pipeline systems utilizing computational fluid dynamics: a predictive framework for evaluating pipeline and structural integrity, with a case study of the Kashagan 28-inch offshore pipeline

Abstract This study conducts a computational fluid dynamics (CFD)-based assessment of internal corrosion risk in wet sour gas pipeline systems, focusing on developing a predictive framework for pipeline integrity. Using the L415 X60 steel pipeline as a reference, the analysis revealed an extreme Corrosion rate of 68,595.942 mm/year, leading to total wall failure in under 12 min. The model was validated through a case study of the Kashagan 28-inch offshore pipeline, known for early failures due to internal corrosion and sulfide stress cracking. Mitigation strategies were evaluated, including corrosion-resistant alloys (CRAs), coatings, liners, inhibitors, H₂S scavengers, and dehydration. A 3 mm CRA cladding, particularly Inconel 625, reduced the corrosion rate from 63711 to 0.055 mm/year due to its Nickel-Molybdenum composition and barrier properties. Hastelloy C-276 showed the lowest corrosion rates. Polymeric liners (Polyethylene of Raised Temperature Resistance, Polyamide12), epoxy coatings, and imidazole-based inhibitors further suppressed corrosion, while complete dehydration eliminated it. These results support CFD-driven models for optimizing corrosion control in sour gas pipelines.