Crude oils contain high molecular weight components such as asphaltenes. These components deposit onto the inner wall of the pipelines and may create a non-uniform barrier between the wall metal surface and the corrosive agents, and reduce the corrosion rates and might affect the wettability of the steel.
The aim of the research is to study the potential benefits of asphaltene deposition for corrosion inhibition and its effect on phase-wetting in oil-water two phase flows. Furthermore to understand the role of asphaltene in competitive inhibition with inhibitive compounds naturally occurring in crude oil.
Experiments were carried out at four different concentrations of asphaltene, i.e. 0, 0.1, 1, and 5 wt % and in two different solvents i.e. toluene and heptol. Acridine was used as a competitive inhibitor. Open-circuit potential, linear polarization resistance, contact angle, and interfacial tension measurements tests were performed.
It was found that asphaltene causes reduction in the corrosion rate and a partial fallout of asphaltene shows even further reduction. A mixture of asphaltene and acridine has strong synergetic effect for both the corrosion rate and the wettability of steel.