Self‐Regulation Mechanisms in Porous Media: The Origin of the Diversity of Fluid Displacement Patterns

During two‐phase fluid displacement in a porous medium, self‐regulation mechanisms provide negative feedback to approach a state of minimum operating power. The versatility of these self‐regulation mechanisms results in a large diversity of fluid displacement patterns. For example, the introduction of a highly tortuous displacement channel, the appearance of the retention and development regions of the displaced phase, and the expansion of the displacement path area of the invading phase are the macroscopic responses of the two‐phase flow system to the self‐regulation mechanisms under different constraints. These new findings provide compelling physical explanations for the underlying mechanisms governing fluid displacement pattern transitions and the influence of inertial effects on the displacement patterns. Key Points The principle of the minimum operating power (MOPR) is proposed The physical origin of the diversity of fluid displacement patterns is clarified The influence of self‐regulating mechanisms on displacement pattern is analyzed