Delineation of microscale regimes of fully-developed drainage and implications for continuum models (Q5959208)

From the conclusions: The authors use a version of percolation theory, based on invasion percolation in a gradient, to connect drainage processes at pore-network scale with the displacement at macroscale. When the mobility ratio is sufficiently small, the displacement is stabilized and can be described by invasion percolation in a stabilizing gradient. In the opposite case, it has common features with invasion percolation in a destabilizing gradient and leads to capillary-viscous fingering. A diagram delineating these two regimes in fully developed drainage is given, and effects of capillarity, viscous forces, gravity and of the correlation of microstructure are examined. Results of this work my have a bearing in the description of real flows in porous materials which is, however, not exposed in the paper.