B. Zhao, C. W. MacMinn, B. K. Primkulov, Y. Chen, A. J. Valocchi, J. Zhao, Q. Kang, K. Bruning, J. E. McClure, C. T. Miller, A. Fakhari, D. Bolster, T. Hiller, M. Brinkmann, L. Cueto-Felgueroso, D. A. Cogswell, R. Verma, M. Prodanovic, J. Maes, S. Geiger, M. Vassvikp, A, Hansen, E. Segre, R. Holtzman, Z. Yang, C. Yuan, B. Chareyre, and R. Juanes. Comprehensive comparison of pore-scale models for multiphase flow in porous media. Proc. Natl. Acad. Sci. USA, 116 (28) 13799-13806, 2019 (pdf).

The simultaneous flow of multiple fluid phases through a porous solid occurs in many natural and industrial processes. Micro-scale physical mechanisms such as the relative affinity of the solid for the fluids (i.e., wettability), capillarity, and viscosity combine with pore geometry to produce a wide variety of macroscopic flow patterns. Pore-scale modeling is an essential tool to connect micro-scale mechanisms with macroscopic patterns, but quantitative comparisons between different models, and with experimental data, are lacking. Here, we perform an unprecedented comparison of state-of-the-art models from 14 leading groups with a recent experimental dataset. The results underscore the challenges of simulating multiphase flows through porous media, highlighting specific areas for further effort in what is already a flourishing field of research.