【摘要】 研究开发适于在超临界CO₂中形成稳定胶束的非离子表面活性剂,是降低CO₂驱最小混相压力的技术关键。采用下悬滴法,研究超临界CO₂与模拟油之间的界面张力,利用直线外推法计算CO₂驱最小混相压力。考察了脂肪醇聚氧丙烯醚以及醇类助剂对CO₂/Oil最小混相压力的影响规律,并确定其最佳用量。结果表明:月桂醇聚氧丙烯醚可大幅度降低超临界CO₂/Oil最小混相压力,随着用量的增加,超临界CO₂/Oil最小混相压力先减小后略微增大,且存在最优值;助剂乙醇可以进一步降低超临界CO₂/Oil最小混相压力,随着添加量的增加,超临界CO₂/Oil之间的最小混相压力先减小后略微增大;随着醇类助剂碳链长度的增加,超临界CO₂/Oil混相压力先减小后增大,乙醇降低CO₂驱混相压力的效果最明显。更多还原

【Abstract】 The development of the stable and micellar non-ionic surfactant produced in the state of supercritical carbon dioxide is the technical key to reduce the minimum miscibility pressure of CO₂ flooding. With the help of underslung pendant-drop method,the interfacial tension between the supercritical CO₂ and simulated oil is studied.In addition,the minimum miscibility pressure of CO₂ flooding is calculated by straight-line extrapolation. The influence laws are investigated for the fatty alcohol polyoxypropylene ether and alcohol additives on the minimum miscibility pressure between the CO₂ and oil,and furthermore the optimal usage is determined. The results show that the lauryl-alcohol polyoxypropylene ether can reduce the minimum miscibility pressure of the supercritical CO₂ and oil to a great deal,with the rise of the usage,the above minimum miscibility pressure decreases first and then increases slowly,and moreover there is the optimal value; the promoting alcohol can further reduce this pressure,with the increase of the amount,the pressure first decreases and later increases slightly; while with the carbon chain length rise of the additive,the miscibility pressure decreases first then increases,the effects of the alcohol are mostobvious on the pressure drop.更多还原