Abstract: By studying the characteristics of high acid crude, it is found that naphthenates not only promote naphthenic acid corrosion, but also increase the difficulty of water/oil system demulsification. The corrosion of unit processing high acid crude could be solved by technologies, such as evaluating the corrosiveness of crude, adopting demulsifier, neutralizing corrosion inhibitor and high temperature corrosion inhibiter comprehensively. Test results show that a new corrosion evaluation method based on copper strip weight loss developed by Research Institute of Petroleum Processing can simulate the corrosion of carbon steel by crude oil veritably. Some tailored demulsifier and metal removing agent packages exhibit excellent demulsification, demetallization, desalting and dehydration effect for processing high acid crude. Neutralizing corrosion inhibitors could effectively suppress "dew point" corrosion in condensing and cooling system; high temperature corrosion inhibiters reduce the corrosion rate at high temperature sites significantly.

Key words: high acid crude, naphthenic acid, corrosion inhibition, desalting