The Role of synthetic hydrocarbon on corrosion behavior of X-65 (UNS K03014) carbon steel in a multi-phase flow system

The role of a synthetic hydrocarbon (Isopar M) on the flow-induced corrosion and erosion-corrosion behavior of X-65 (UNS K03014) carbon steel has been investigated in CO-saturated conditions. A rotating cylinder electrode (RCE) was used in conjunction with electrochemical techniques and gravimetric measurements to determine the influence of hydrocarbon at various rotation speeds. The addition of 20% Isopar M formed an oil-in-water emulsion which was found to increase the rate of anodic dissolution of carbon steel, particularly at low rotation speeds. At higher flow velocities, emulsion stability and competitive wettability helped to minimize the corrosive impact of the hydrocarbon. The synthetic hydrocarbon phase was believed to increase the kinetics of the corrosion reaction while also reducing the impact energy from impinging sand particles under erosion-corrosion conditions. A water-in-oil emulsion was formed at a water cut of 20% which reduced degradation rates. This effect was most likely attributed to a reduction in surface wettability by the brine phase. Degradation mechanisms are also interpreted using scanning electron microscopy.