Effect of Water Cut on the Localized Corrosion Behavior of P110 Tube Steel in Supercritical CO₂/Oil/Water Environment

Corrosion behavior of P110 tube steel was investigated in supercritical CO₂/oil/water environment. A corresponding corrosion mechanism was proposed based on the understanding of the formation of localized corrosion. The results show that uniform corrosion occurs within the range of 0% to 30% water cuts, with the corrosion rate much lower than 1 × 10⁻² mm/y. When water cut increases to 50%, the corrosion rate of P110 steel increases rapidly and the corrosion morphology changes from uniform corrosion to localized corrosion. Crude oil in low proportions causes considerable localized damage to the steel as a result of the inhomogeneous wetting of steel surface by crude oil in a CO₂/oil/water system.