Comparison of Laboratory Methodologies to Evaluate Corrosion Inhibitors for Oil and Gas Pipelines

Experiments were carried out using a loop in three fields (gassy-oil, oily-gas, and oil-transmission pipes) under 17 operating conditions, using six inhibitors (three continuous and three batch). Laboratory experiments were carried out under field conditions using the same inhibitors at the same concentrations. Four types of data were used to compare the laboratory and field results: general corrosion rates, pitting corrosion rates, percentage inhibition calculated from general corrosion rates, and percentage inhibition calculated from pitting corrosion rates. Based on the comparison, the following laboratory methodologies were ranked: wheel test, bubble test, static test, rotating disc electrode (RDE), rotating cylinder electrode (RCE), jet impingement (JI), and rotating cage (RC).