不同润湿条件下表面活性剂对残余油的作用

Effects of Surfactants on Residual Oil in Different Wetting Media

利用微观可视化驱油实验,研究了不同润湿条件下,具有不同降低界面张力的表面活性剂体系对水驱残余油的作用情况。结果表明,水湿条件下,表面活性剂通过形成连续油流或水包油乳状液启动残余油,且两者分别是驱替初期和后期的主要残余油运移方式;油湿条件下,表面活性剂还能通过形成油包水乳状液启动残余油,且油包水乳状液和沿孔壁流动的细油带是驱替初期的残余油主要运移方式,而水包油乳状液是驱替后期的主要残余油运移方式。同时,在两种润湿条件下,表面活性剂对残余油的启动与运移作用均随其界面张力的降低而增强。

The effects of surfactant systems with different capacities of reducing IFT in different wetting media on residual oil after water flooding were researched by using micro-visualization displacement experimenl. The results show that in water-wet medium, the surfaelant may start residual oil by forming successive oil stream and water-in-oil emulsion, which is the main residual nil migration mode for initial and later stages of displacement; in oil-wet medium, the surfactant may also start residual oil by forming water-in-oil emulsion, but the main residual nil migration mode for initial stage of displacement is thin oil belt along pore wall and water-in-oil emulsion, whereas that for later stage of it is oil-in-water emulsion. Meanwhile, in these two wetting media, the start-up and migration effects of surfactant on residual oil en- han（＇e with IFT reducing.