New equations predicting the best performance of electrostatic desalter

Production of wet crude due to the raise in oil-water contact in many Iranian oil fields had been a growing field problem. Application of the right technology and installation of proper desalting facilities were required to solve this problem. Therefore, it was decided to install electrostatic desalting plants progressively in Iranian oil fields. By end of 2004, more than 20 plants with a total capacity of 1.3 MMSTB/day of treated crude had been installed. It is expected that production of wet crude will rise to 2.3 MMSTB/day in Iran by the year 2007. The performance of the majority of current desalting plants have been tested and found satisfactory. New equations covering a wide range of oil types are developed to estimate the optimum treating rate, treating temperature, and treating viscosity for dual polarity and AC conventional electrostatic desalters in Iranian oil fields. Based on these equations, this study suggests that dual polarity electrostatic desalters are more beneficial economically when compared with AC conventional electrostatic desalters. Dual polarity desalters may operate at a minimum crude oil inlet temperature, resulting in extra fuel savings, eliminating the need for a heating system in the vessel. Also, its treating rate is more than AC conventional electrostatic desalters.