Evaluation of the effectiveness of commercial demulsifiers based on polyoxyalkylated compounds in relation to oil and water emulsions of the Sarybulak oilfield

Abstract

Water and oil emulsion formation is a natural process that takes place during oil recovery and processing. Heavy oils of Kazakhstan form highly stable oil emulsions mostly stabilized by a high content of asphaltenes, resins, and other surface-active components. Oil-in-water emulsions initiate the corrosion of equipment and cause transportation issues. Dewatering of oil emulsions is economically reasonable and requires universal techniques which could be applied to any sort of oil. In this study, the chemical composition of crude oil from the Sarybulak oilfield was determined, and commercial demulsifiers of Basorol brand were applied to these water-in-oil emulsions. The natural stabilizers content (asphaltenes and resins) was determined and correlated with IR-spectrum data. Finally, the effectiveness of demulsifiers is compared and explained according to their structures. It has been found that the higher the relative solubility number of the demulsifier, the better water-in-oil emulsion separation efficiency and dewatering mechanism was assumed. Results of water separation showed that Basorol PE-10400 and PE-10500 are the most effective, with DE of 96% and 91%, respectively, for 30% (vol.) water-in-oil emulsion at 60°C during 1-hour treatment.