孤岛聚合物驱原油沥青质乳化能力研究

Study on emulsification of Gudao crude oil asphaltene in polymer flooding

沥青质是原油乳化的活性组分,研究沥青质对乳状液稳定性的影响,有助于明确聚驱采油污水含油过高的原因。从孤岛原油中分离正戊烷和正庚烷沥青质,运用红外光谱分析了其官能团差异,通过考察模拟地层水、聚合物和粘土对2种沥青质的乳化和界面张力性质的影响。结果表明,模拟地层水使正戊烷沥青质的乳化能力减弱,使正庚烷沥青质乳化能力增强;随着聚合物浓度增大,乳化能力增强,聚合物浓度在500 mg/L时,界面张力最大;粘土浓度小于200 mg/L时,对乳状液具有破乳作用,大于200 mg/L时,则随粘土浓度增加,乳化能力增强,粘土浓度在300 mg/L左右,界面张力最小。

Asphaltene is an active component of emulsified crude oil.It is beneficial to understand the reason of high oil content in waste water by studying the influence of asphaltene on emulsion stability.Normal pentane and heptane asphaltenes separated from Gudao crude oil are analyzed for functional group by infrared spectrum.The influence of simulated formation water,polymer and clay on emulsification and interfacial tension of the two asphaltenes is investigated.The result shows that:The emulsification of n-pentane asphaltene is weakened in simulated formation water,while the emulsification of n-heptane asphaltene is enhanced.The emulsification enhances as the increasing of polymer concentration.The interfacial tension is maximum at polymer concentration of 500 mg/L; clay palys a role of demulsification at concentration less than 200 mg/L,the emulsification will enhance when clay concentration is over 200 mg/L,and the interfacial tension is minimum at clay concentration of 300 mg/L.