The effect of wettability on waterflooding oil recovery and the associated pore-scale displacement mechanisms are systematically investigated during flow processes in limestone core samples with a broad spectrum of wettability. Using a miniature core-flooding setup integrated with micro-computed tomography (CT) imaging apparatus, we, for the first time, characterize in situ equilibrium wettability states and demonstrate capillary interactions of the flowing phases in strongly water-wet (SWW), intermediate-wet (IW), weakly oil-wet (WOW), and strongly oil-wet (SOW) systems. The microscale observations were then employed to explain the recovery results obtained from replicate, macroscale experiments. The waterflooding parameters, such as experimental temperature, brine composition, defending and invading phase properties, and the initial water saturation, were maintained nearly identical in all of the waterflooding tests, thereby ensuring that the wettability state was the only factor that controlled the variations in waterflood oil recoveries. We provide pore-scale evidences of various pore-scale displacement mechanisms and the consequent fluid configurations in systems with different wettability states. These findings are then linked to the recovery trends of macroscale experiments. The production from IW, WOW, and SOW cases portrayed a prolonged oil recovery owing to the gradual invasion of brine into small and intermediate-sized oil-wet pores. The IW case showed the highest oil recovery among all cases. Moreover, when the injection flow rate was increased, the oil recovery was gradually increased for the IW, WOW, and SOW systems, whereas no significant additional production was observed in the case of SWW.

在流动性广的石灰岩岩心样品的流动过程中，系统地研究了润湿性对注水采油率的影响以及相关的孔垢驱替机理。我们使用与微型计算机断层扫描（CT）成像设备集成的微型注水装置，首次表征了原位平衡润湿性状态，并展示了强水湿（SWW）中间层中流动相的毛细管相互作用-湿（IW），弱油湿（WOW）和强油湿（SOW）系统。然后采用微观观测来解释从重复的宏观实验获得的回收率结果。注水参数，例如实验温度，盐水成分，防御和侵入相的特性，在所有注水测试中，初始含水量和初始含水饱和度都保持几乎相同，从而确保了润湿状态是控制注水采收率变化的唯一因素。我们提供了具有不同润湿性状态的系统中各种孔隙尺度位移机制以及随之而来的流体构型的孔隙尺度证据。然后将这些发现与宏观实验的恢复趋势联系起来。IW，WOW和SOW案例的生产表明，由于盐水逐渐侵入中小型油湿孔隙中，因此采油时间得以延长。在所有案例中，IW案例均显示出最高的采油率。此外，当增加注入流量时，IW，WOW和SOW系统的采油率逐渐提高，