The Emulsification Mechanism and Demulsification of Crude Oil in EBS Oilfield

The emulsions of crude oil can seriously affect the efficient production of oil wells. The formation of emulsions is closely related to the properties of crude oil and production water. It is an importantly practical significance to study the emulsification mechanism of crude oil with different properties and select efficient demulsifiers. Using EBS oilfield crude oil as the research object, the fractions and properties of different crude oils were tested. Indoor simulation of emulsion formation was conducted to investigate the effects of different factors, such as water content, pH value and temperature, on the emulsification of different crude oils. Through bottle test experiments, the demulsification effect of block polyether demulsifiers on different crude oil emulsions was evaluated. The results showed that the higher the content of asphaltene and resin in crude oil, the closer the asphaltene molecules may be arranged at the oil-water interface, the higher the strength of the oil-water interface facial mask formed, the more stable the emulsion, and the greater the viscosity. The water content of crude oils with different properties varied when they reached complete emulsification. The stability of the emulsion may deteriorate under acidic conditions or when the temperature increased. With the addition of effective demulsifier, block polyether molecules could replace asphaltene molecules at the oil-water interface, reduce the strength of interfacial facial mask, and achieve oil-water separation. The study revealed the mechanism of crude oil emulsification in EBS oilfield, clarified the influence rules of different factors on crude oil emulsification, and selected demulsifiers with strong adaptability and high demulsification efficiency.