Comparative Study of Crude Oil Dehydration Equipments

Abstract

The present study addresses all facets of an efficient, compact and environmentally acceptable crude oil
dehydration operation based on three different equipments. The equipments considered for the purpose of this
research are a gravity settler (liquid-liquid) separator, heater-treater system and electrostatic coalescer. Case
studies present the effect of crude oil properties and operating conditions on the right decision of equipment
selection. The selection is based on mathematical equations that characterize the choices of the separation system
through the determination of the required size and expected efficiency. The results of this study showed that the
gravity settler is most suitable for dehydration of light density (less than 850 kg/m3) and low water-cut (less than
40%) crudes. The heater-treater system is found to be most suitable when dehydration of viscous and high water
cut crudes is considered. Furthermore the study concludes that the electrostatic coalescer is most suitably used for
dehydration of crude oil with water cut 20% or less, as expected, because short circuiting occurs above this limit;
In the cases where crude water cut is less than 20%, the electrostatic coalescer showed the highest expected
efficiency with the lowest equipment size requirements