Abstract:

A great number of oilfield chemicals are used in oil fields for enhancing oil recovery and oil transport in China. Some of these chemicals directly come into crude oils, resulting in the corrosion of refinery equipments. It was thought that the corrosion inhibitor is believed to be one of the causes of equipment corrosion. The thermal decomposition simulation experiments were performed to understand the changes of typical corrosion inhibitors in oil refining processes. The mechanism of these changes leading to the corrosion was analyzed. It is found that as the decomposition temperature rises, the concentration of inorganic Cl- increases in inhibitors tested at 120 ℃ and increases markedly at 360 ℃, compared with the one before heating. It is concluded that the production of Cl- is due to the hydrolysis or cracking reactions of some of stable compounds in corrosion inhibitors.

Key words: oilfield corrosion inhibitor, corrosion, thermal decomposion, oil refining, chlorine