Electrochemical evaluation of under-deposit corrosion and its inhibition using the wire beam electrode method

A new experimental method has been applied to evaluate under-deposit corrosion and its inhibition by means of an electrochemically integrated multi-electrode array, namely the wire beam electrode (WBE). Maps showing galvanic current and corrosion potential distributions were measured from a WBE surface that was partially covered by sand. Under-deposit corrosion did not occur during the exposure of the WBE to carbon dioxide saturated brine under ambient temperature. The introduction of corrosion inhibitor imidazoline and oxygen into the brine was found to significantly affect the patterns and rates of corrosion, leading to the initiation of under-deposit corrosion over the WBE.

Research highlights► A new experiment method for evaluating under-deposit corrosion and its inhibitors. ► Under-deposit corrosion did not occur in a CO2 saturated pure brine solution. ► Inhibitor imidazoline addition and O2 contamination initiated under-deposit corrosion. ► Inhibitor imidazoline reduced general corrosion but enhanced localised corrosion.