Effect of Oil-Water Intermittent Wetting on Corrosion Inhibition of Carbon Steel in CO₂ Environment

Produced water can cause internal corrosion in oil pipelines. The flow of hydrocarbons and water can result in intermittent surface wetting, impacting corrosion inhibition. However, this is still poorly understood. This research uses electrochemical techniques to study the impact of intermittent wetting and the wettability of the steel surface on corrosion inhibition. An inhibitor model compound and model oil were used at 25°C and 55°C in CO₂-saturated solutions. Corrosion inhibition varied with temperature and steel surface hydrophobicity, altering inhibition significantly after intermittent contact with hydrocarbon at 55°C. Electrochemical impedance spectroscopy and wettability results revealed distinct protective mechanisms when oil was present.