A synergistic experimental and computational study on CO2 corrosion of X65 carbon steel under dispersed droplets within oil/water mixtures

Abstract

The CO₂ corrosion behaviour of X65 carbon steel under water-in-oil droplet and oil-in-water droplet was systematically investigated by a combination of scanning electron microscopy, Raman spectroscopy, NPFLex3D and COMSOL simulation. Under the water-in-oil droplet, the formation of crystalline FeCO₃ can be contributed to the high concentration of Fe²⁺ and CO₃^2-, and the short diffusion path near the droplet edge promotes FeCO₃ precipitation. Under the oil-in-water droplet, corrosion islands caused by the invasion of water can be found, indicating that the small water droplets emphasised the development of localized corrosion underneath the oil droplet.