表面活性剂的乳化性能和界面活性对低渗油藏采收率的影响

Effects of Surfactant’s Emulsifying Capacity and Interfacial Activity on Oil Displacement in Low-permeability Reservoir

吴志伟

WU Zhiwei

为明确表面活性剂的乳化性能和界面活性对水驱后残余油或剩余油影响的主次关系，结合冀东油田渗透率低、窜流严重、化学驱条件适宜等油藏特点，筛选出乳化性能强、界面活性较差和乳化性能较差、界面活性较强的表面活性剂体系，在渗透率相近的岩心中开展了水驱后驱油实验。结果表明：适和冀东油田高63-10 断块两种表面活性剂复配体系为：乳化水率较好、界面张力达10-2mN/m的体系0.2%非离子表面活性剂6501+0.1%阴离子表面活性剂XPS 和乳化水率较差、界面张力达到10-3mN/m的体系0.1% XPS+0.5% NaCl；水驱后注0.1% XPS+0.5% NaCl 体系的采收率增幅为2.73%，注0.2% 6501+0.1% XPS体系的采收率增幅为5.78%，乳化携带和聚并对残余油滴和局部剩余油驱替效果远好于界面活性的作用；综合发挥界面张力（10-2mN/m）和乳化的作用能降低对界面活性的要求，这为表面活性剂筛选提供了实验依据和技术思路。图13 表3 参22

To clarify primary or secondary effect of emulsion and interfacial tension on remaining oil after water flooding in low-permeability reservoir，in view of Jidong oilfield reservoir condition with low permeability，severe channeling and suitable condition for chemical flooding，the system which had greater emulsifying capacity and lower interfacial tension and the other system which had lower emulsifying capacity and higher interfacial tension were selected. Flooding experiments after water flooding with these systems were carried out in the cores with similar permeability. The results showed that two compound systems which met the need of Gao 63-10 block in Jidong oilfield were obtained as follows: 0.2% nonionic surfactant 6501+0.1% anionic surfactant XPS and 0.1% XPS+0.5% NaCl. The former system had great emulsifying capacity and its interfacial tension could reach 10-2 mN/m. The latter system had worse emulsifying capacity and its interfacial tension could reach 10-3 mN/m. The enhanced oil recovery of 0.1% XPS+0.5% NaCl system after water flooding was 2.73%，while that of 0.2% 6501+0.1% XPS system was 5.78%. In low-permeability reservoir，oil displacement effect of emulsifying carry and coalescence to remaining oil and residual oil was better than that of interfacial activity. The combination of emulsion and interfacial tension （10-2 mN/m） could reduce the requirements of interfacial activity which provided experiment basis and technical idea for screening surfactant in surfactant flooding.

10.19346./j.cnki.1000-4092.2017.01.025