BW区原油活性物对化学驱界面张力的影响

The Effect of Active Substance in the Crude Oil of Block BW on Interfacial Tension During Chemical Flooding

原油中活性物质对化学驱配方的界面张力大小有着重要影响。提取了新疆油田BW区原油的活性物质,研究了活性物跟石油磺酸盐和碱的界面张力。结果显示,BW区原油的胶质、沥青质含量偏低,界面活性物质主要存于在乙酸乙酯洗脱液中,其主要成分为C_(n)H_(2n-2)O_(2)和C_(n)H_(2n-4)O_(2)两种类型,包括酚、醇类和羧酸类。单独加入Na_(2)CO_(3)后,界面张力可降低至10-2 mN/m;单独加入石油磺酸盐,界面张力降低效果较差,只达0.5 mN/m;同时加入石油磺酸盐和Na_(2)CO_(3)后,界面张力很快下降至10^(-3) mN/m。主要是因为碱和乙酸乙酯洗脱液部分成分发生反应,生成了增强石油磺酸盐性能的激活剂,使得界面张力大幅度下降。

The active substance in crude oil has an important influence on the interfacial tension of chemical flooding formula.After ac-tive substance in the crude oil of Block BW in Xinjiang Oilfield was extracted,the interfacial tensions between it and petroleum sulfo-nate(KPS)and alkali were studied.The results show that the contents of resin and asphaltene in the crude oil are very low,and the in-terfacial active substance mainly exists in ethyl acetate eluent.Main components of the active substance include phenols,alcohols and carboxylic acids,which fall into two types of CnH_(2n-2)O_(2)and CnH_(2n-4)O_(2).With Na_(2)CO_(3) added,the interfacial tension was reduced to 10^(-2) mN/m.With KPS added,the interfacial tension was only reduced to 0.5 mN/m,showing a poor effect.After adding both KPS and Na_(2)CO_(3) together,the interfacial tension was quickly reduced to 10^(-3) mN/m.This is mainly because that alkali reacts with some compo-nents of ethyl acetate eluent,and an activator to enhance the performance of petroleum sulfonate is produced,which greatly reduces the interfacial tension.