原油组成对电场改性效果的影响

Influence of oil composition on the cold flowability improvement of electric field treatment

电场改性是一种新型的原油改性方法,其基本原理是电流变效应,机理是蜡晶的界面极化。目前研究发现,不同原油电场改性效果差异较大,机理尚不明确。以胶质、沥青质含量介于4%~23%的8种含蜡原油为实验对象,测试其电场改性效果,发现胶质、沥青质含量少(总质量分数5%以下)的原油,在实验条件下电场降黏效果随累计析蜡量增大呈先升后降趋势;对于胶质、沥青质含量中等的原油(总质量分数10%左右),在实验条件下电场降黏效果随累计析蜡量增大单调上升;对于胶质、沥青质含量较高(总质量分数15%以上)的原油,在实验条件下电场降黏效果不明显。结合界面极化机理,得出电场改性效果强弱与原油中胶质、沥青质的充足程度及聚集程度密切相关。

Electric field treatment is a new method to improve the cold flowability of waxy crude oil.Its basic principle is electrorheological behaviors of waxy oil,and its mechanism is the interfacial polarization of wax particles.So far,researchers have found that the effect of electric field treatment varies greatly among different crude oils,yet the mechanism is unclear.Herein,the effect of electric field treatment on improving flowability was tested using 8 waxy crude oils with various resin and asphaltene contents ranging within 4%to 23%.The results show that:under the experimental conditions,the crude oils with lower resin and asphaltene content(of which the total mass fraction is less than 5%)have the viscosity reduction effect induced by electric field increase first and then decrease with the increasing of cumulative amount of wax precipitated;the crude oils with medium resin and asphaltene content(of which the total mass fraction is about 10%)have the viscosity reduction effect induced by electric field increase monotonically with the increasing of precipitated wax;the crude oils with high resin and asphaltene content(of which the total mass fraction is above 15%)have unobvious viscosity reduction effect induced by electric field.It is concluded according to the mechanism of interfacial polarization of wax crystal particles of flowability improvement by electric field treatment is closely related to the abundance and aggregation degree of rein and asphaltene in crude oil.