Water/oil flow characteristics in a water-wet capillary were simulated at the pore scale to increase our understanding on immiscible flow and enhanced oil recovery. Volume of fluid method was used to capture the interface between oil and water and a pore-throat connecting structure was established to investigate the effects of viscosity, interfacial tension (IFT) and capillary number (Ca). The results show that during a water displacement process, an initial continuous oil phase can be snapped off in the water-wet pore due to the capillary effect. By altering the viscosity of the displacing fluid and the IFT between the wetting and non-wetting phases, the snapped-off phenomenon can be eliminated or reduced during the displacement. A stable displacement can be obtained under high Ca number conditions. Different displacement effects can be obtained at the same Ca number due to its significant influence on the flow state, i.e., snapped-off flow, transient flow and stable flow, and ultralow IFT alone would not ensure a very high recovery rate due to the fingering flow occurrence. A flow chart relating flow states and the corresponding oil recovery factor is established.

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在孔尺度上模拟了水湿毛细管中的水/油流动特性，以增加我们对不混溶流动和提高油采收率的理解。用流体体积法捕获油与水之间的界面，建立了孔喉连接结构，以研究粘度，界面张力（IFT）和毛细管数（Ca）的影响。结果表明，在注水过程中，由于毛细作用，初始连续油相可能会在水润湿的孔隙中断裂。通过在润湿阶段和非润湿阶段之间改变驱替液的粘度和IFT，可以在驱替过程中消除或减少折断现象。高钙下可获得稳定的位移数量条件。由于相同的Ca值会对流动状态产生重大影响，因此，在相同的Ca值下可以获得不同的位移效果，即折断流动，瞬态流动和稳定流动，而仅通过手指进行超低IFT操作就不能确保很高的回收率。流发生。建立了与流动状态和相应的油采收率有关的流程图。

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