Influence of Fe3C on corrosion inhibition efficiency of Benzyldimethylhexadecylammonium chloride: Galvanic Corrosion interaction and adsorption behaviour

Corrosion products formation on carbon steel in oil and gas environments can induce galvanic corrosion and hinders corrosion inhibitor (CI) adsorption due to surface heterogeneities (i.e., roughness, competitive adsorption, CI displacement, etc.). This study uniquely explores the role of Fe3C in influencing galvanic interactions and CI performance under dynamic flow conditions, addressing a critical gap in the literature. The presence of Fe3C reduces the adsorption and efficiency of quaternary ammonium compounds (QAC), with limited research available on its impact in real-world pipeline environments. Benzyldimethylhexadecylammonium chloride was used as a CI for X60 carbon steel in a CO2 environment. The study investigated the inhibitory effects and preferential adsorption behaviour of the X60/Fe3C system through electrochemical tests and surface characterization under harsh, high-salinity conditions simulating Qatar’s fields. Results demonstrated an inhibition efficiency of 92.7% for galvanic corrosion and higher efficiency against general corrosion.