Abstract: For the poor stability of general foams, NanoSiO₂ was added into surfactant solution to increase the stability of foams. The surface tension and surface dilatational properties of the compounded system were measured by Tracker Interfacial Rheometer. The distribution of remaining oil and its oil displacement mechanism at each method of displacement were analyzed by microscopic model. The effect of oil recovery with two different foam systems was also studied by core experiments. It was proved that the increase of surface dilatational modules was the main reason for foam stability which can increase the sweep area and extrusion for oil on the channel wall. The core flooding results showed that both the oil recovery and the pressure drop increased with the SiO₂/SDS foam system. 

Key words: NanoSiO₂,    ,     Surface tension,    ,  Interfacial rheological property,     ,  Microscopic model,    ,  Oil recovery efficiency

摘要： 针对普通泡沫稳定性差的缺点, 在表面活性剂中加入纳米 S i O₂ 从而提高泡沫的稳定性。利用 T r a c k e r全自动界面流变仪测量了复配体系的表面张力和界面扩张模量; 利用可视化刻蚀模型, 探明了不同驱替方式的剩余油分布状况; 利用岩心实验, 对比了两种不同泡沫体系岩心驱替效果。结果表明, 纳米S i O₂ 颗粒与S D S复配后, 体系的起泡体积有所降低, 但是泡沫稳定性明显增强; 纳米S i O₂ 颗粒加入到S D S溶液后对体系的表面张力影响不大, 但是界面黏弹性显著增加; 微观驱油实验和岩心驱替实验结果表明, 复配泡沫体系可以加强对孔道内壁油的挤压、 携带作用, 提高岩心两端的压差, 从而增加波及面积, 提高采收率。

关键词: 纳米S i O₂, 表面张力, 界面流变性, 微观模型, 采收率