This study examines the dynamics of two-phase drainage with experiments of air invasion into a translucent water-saturated porous medium, at low injection speeds. Air displaces the water by irregular bursts of motion, suddenly invading small portions of the medium. These periods of activity,...

For two decades, invasion percolation (IP) has provided a simple model of ‘drainage’ where a non-wetting fluid is injected into a porous media saturated with a wetting fluid, in the limit where capillary forces dominate and viscous forces are negligible. IP produces a characteristic...