Leveraging high-fidelity lattice Boltzmann simulations combined with analytical modeling, we establish a comprehensive micro-scale description of immiscible two-phase fluid displacement occurring during favorable and unfavorable displacement conditions in a heterogeneous porous medium under a wide range of wettability. The emergence of corner-flow events is found to promote a compact displacement pattern, leading to a maximum recovery efficiency of the defending fluid under the strong imbibition for both favorable and unfavorable displacement scenarios. Saturation of the invading fluid manifests the crossover in the displacement patterns from fingering to stable flow, as the wetting varies from drainage to strong imbibition. Quantifying the corner flow under both displacement conditions and strong imbibition reveals that corner-flow events are preferentially hosted by small-size pores and predominantly concentrated ahead of the primary fluid–fluid interface without perturbing the stability of the pore-body displacement. In addition to the numerical simulation, we developed an analytical model that can predict the saturation profile of invading fluid under given boundary conditions. Our study elucidates the fundamental control and interaction of wettability and heterogeneity on the dynamics of immiscible fluid displacement in porous media with implications in the description of subsurface flow and processes.

利用高保真晶格玻尔兹曼模拟与分析模型相结合，我们建立了一个广泛的微观尺度描述，该模型描述了在广泛的润湿性下，在非均质多孔介质中有利和不利驱替条件下发生的不混溶两相流体驱替。发现角流事件的出现促进了紧凑的驱替模式，从而在有利的和不利的驱替情况下，在强吸力作用下，保卫液的回收效率达到了最大。浸润液的饱和表现出从指状到稳定流动的位移模式的交叉，因为润湿从排水到强烈的吸水变化。定量分析在位移条件和强吸力作用下的角流，结果表明，角流事件优先由小孔占据，并且主要集中在主要流体-流体界面的前面，而不会影响孔-体位移的稳定性。除了数值模拟之外，我们还开发了一种分析模型，可以在给定的边界条件下预测侵入流体的饱和度曲线。我们的研究阐明了润湿性和非均质性对多孔介质中不混溶流体驱替动力学的基本控制和相互作用，对地下流动和过程的描述具有重要意义。