Fluid-fluid displacement in mixed-wet porous media

Wettability exerts fundamental control over multiphase flow in porous media, which has been extensively studied uniform-wet media. In contrast, mixed-wet media is less well-understood. We combine microfluidic experiments and pore-scale simulations to study the displacement of oil by water a mostly oil-wet patterned with discrete water-wet clusters. Our work demonstrates complex nature wettability it presents experimental numerical platforms upon further insights can be drawn.