Displacement mechanisms of enhanced heavy oil recovery by alkaline flooding in a micromodel

► An enhanced oil recovery (EOR) method by alkaline flooding for heavy oils was studied in a micromodel, revealing two underlying mechanisms may be at work, i.e., in situ water-in-oil (W/O) emulsion formation and oil-in-water (O/W) emulsion formation with the aid of surfactant. ► The two mechanisms are applicable for different reservoir conditions.