【摘要】 二元复合驱能够大幅度提高水驱后油藏采收率,为深化二元复合体系提高采收率机理认识,开展二元复合体系界面活性与乳化性能协同提高采收率研究。通过物理模拟实验、微观可视化驱替实验和核磁共振实验,研究具有不同界面活性和乳化性能二元复合体系的驱油效果,明确渗流过程中其界面活性变化规律,阐明油水界面张力与乳化性能协同提高采收率机理。结果表明,由于油藏的非均质性及驱油体系性能变化,二元复合体系与原油界面张力并非越低越好。过高界面张力不利于洗油效率的提高,而过低界面张力不利于乳化作用的发挥。当油水界面张力与乳化性能配伍关系良好时,二元复合体系既可以利用较低界面张力启动油藏深部残余油,又可以通过残余油滴封堵大孔道,改变油藏深部流场分布,降低非优势层剩余油饱和度,实现大幅度提高采收率的目标。更多还原

【Abstract】 The binary compound flooding can dramatically improve oil recovery after water flooding.In order to have a better understanding of the enhanced oil recovery(EOR)mechanism of binary compound system,the synergistic effect of interfacial activity and emulsifying properties on EOR was studied.The physical simulation experiments,microscopic visualized displacement experiments,and nuclear magnetic resonance(NMR)experiments were applied,with the purpose to study the oil displacement effect of the systems with different interfacial activity and emulsifying properties,to clarify the change law of interfacial activity of the system during the percolation,and to illustrate the synergistic effect of interfacial tension and emulsification on enhancing oil recovery.Results show that because of the reservoir heterogeneity and the performance change of compound system,a lower interfacial tension between the system and oil may not get a better oil recovery.A high interfacial tension is negative to improve the displacement efficiency.However,a low interfacial tension results in an ignorable emulsification effect.When the oil-water interfacial tension and emulsifying properties match well,the residual oil in deep reservoir may be produced at low interfacial tension of the binary compound system.At the same time,oil droplets could plug large throats to change deep flow field distribution and to reduce remaining oil saturation of non-preferred stratum.All of these would reach the aim to dramatically enhance oil recovery.更多还原