Evaluation of a New Sour Gas Corrosion Inhibitor in Field Applications via Localized Corrosion Monitoring Techniques

A new corrosion inhibitor was developed for application in sour gas production in Canada.  During the development process, controlling pitting corrosion in laboratory testing was important for evaluating inhibitor performance.  This criterion was set because pitting or localized corrosion is the most significant internal corrosion threat in sour gas production.  Evaluation of the corrosion inhibitor in the laboratory testing used scanning optical profiling to image the exposed coupons and electrochemical testing to monitor localized corrosion.  At the end of the development stage a field trial was set up in a Canadian gas field with salty sour production consistent with the conditions the inhibitor was exposed in laboratory testing.  During the field trial the same techniques were used to evaluate field coupons and electrochemically monitor the corrosion.  Using the field data the corrosion inhibitor performance was evaluated.  Observations of localized corrosion in the laboratory setting and field setting were compared in order to understand whether laboratory testing accurately mimicked that of the field.