Local Wettability Reversal during Steady-State Two-Phase Flow in Porous   Media
  We study the effect of local wettability reversal on remobilizing immobile fluid clusters in steady-state two-phase flow in porous media. We consider a two dimensional network model for porous medium and introduce a wettability alteration mechanism. A qualitative change in the steady state flow patterns, destabilizing the percolating and trapped clusters, is observed as the system wettability is varied. When capillary forces are strong a finite wettability alteration is necessary to move the system from single-phase to two-phase flow regime. For the case of both phases being mobile we find a linear relationship between fractional flow and wettability alteration. 
Santanu Sinha, Morten Gr{\o}va, Torgeir Bryge {\O}deg{\aa}rden, Erik   Skjetne and Alex Hansen
physics.flu-dyn physics.comp-ph