The Effective Parameters on the Coalescence of Water in Crude Oil by Means of Electrostatic Coalescers

In this study, demulsification of water-in-crude oil emulsions was investigated under various conditions by means of electrostatic dehydrator. The effects of various parameters including temperature, voltage, surfactant concentration, salinity, and water content of the West Paydar crude oil emulsion on the separation efficiency were evaluated. To evaluate the effect of temperature, concentration of surfactant and salinity, emulsions of 20 vol% of water in crude oil were prepared. To overcome the effect of asphaltene and resin of the crude oil in stabilizing the emulsions, SDS was used as a demulsification reagent. Emulsions containing 30 wt% of SDS in water were prepared. By increasing the electrice field from 0 to 6 kV/cm, at 22˚C, efficient separation of West Paydar crude oil emulsions was occurred. The normal separation at ambient temperature was 62% which was increased to 86% at 44˚C. Increasing the temperature up to 53 °C increased the separation of water up to about 92% while applying 6 kV/cm. Increasing the concentration of surfactant from 0 to 2.3 vol% at 6 kV/cm and 28˚C increased the water separation up to 75%. Increase in the water salinity of the West Paydar crude oil emulsion decreased the water separation. Increasing the water content of the emulsion from 10 to 30 vol% increased the water separation from 30 to 84%.