In Situ Assessment of Pitting Corrosion and Its Inhibition Using a Localized Corrosion Monitoring Technique

Abstract Pitting corrosion of pipelines remains a serious concern to operators in the oil and gas industry. Pitting is a particularly insidious and extremely rapid form of attack of a metal structure that can lead to unexpected system failures. The pipe wall can be perforated within a relatively short space of time with no appreciable metal loss on the pipeline as a whole. Corrosion inhibitors are widely used by operators to maintain asset integrity, and their effect on controlling general corrosion to acceptable levels is easily demonstrated by the use of weight-loss coupons or techniques such as linear polarization resistance (LPR). However, up to 80% of pipeline failures are ascribed to pitting, but very few monitoring methods are capable to show this outcome. This paper discusses a localized corrosion monitoring (LCM) technique, which has been utilized to provide in situ quantitative assessment of pitting corrosion under laboratory-simulated wet sour gas operating conditions. The predicted pitting dam...