Surfactant‐aided gravity drainage is an improved oil recovery technique for water‐invaded zone in fractured carbonate reservoirs, which are mostly oil‐wet or mixed‐wet rocks. The re‐infiltration mechanism in water‐invaded zone has a considerable effect on oil vertical movement in gravity drainage processes. In this work, a mechanistic understanding of re‐infiltration in surfactant‐aided gravity drainage, in comparison to oil–water gravity drainage is presented using an experimentally and numerically validated model. A column model is constructed from three matrix blocks. These blocks are separated from each other by horizontal fractures. A storage tank is considered on top of the model to store depleted oil from matrix blocks. The stacked‐blocks model for re‐infiltration is validated and verified to simulate water and chemical flooding using a mesh independency study and experimental flooding data in a composite core experiment. Using this model, several analyses are performed to investigate effects of rock and fluid properties, rock saturation functions, wettability alteration, surfactant adsorption, and capillary continuity on re‐infiltration.

中文翻译：

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通过表面活性剂辅助重力排水过程，对天然裂缝性储层中的再渗透进行机械理解

表面活性剂辅助重力排水是一种裂缝性碳酸盐岩油藏水侵带的改进的采油技术，碳酸盐岩油藏主要是油湿或混湿岩石。渗水区的再渗透机制对重力排水过程中的油垂直运动有相当大的影响。在这项工作中，通过实验和数值验证的模型，提出了与油水重力排水相比，表面活性剂辅助重力排水中再渗透的机械理解。列模型由三个矩阵块构成。这些块通过水平裂缝彼此分开。模型顶部考虑了一个储油罐，用于储存来自基体块的贫油。使用网格独立性研究和复合岩心实验中的实验驱替数据，对用于再渗透的叠层模型进行了验证和验证，以模拟水和化学驱。使用该模型，进行了多次分析，以研究岩石和流体特性，岩石饱和度函数，润湿性改变，表面活性剂吸附和毛细管连续性对再渗透的影响。