Alkali-surfactant flooding is an established enhanced oil recovery technique in conventional oil reservoirs, whereby the injected chemical lowers the oil/water interfacial tension, leading to reduced trapping of oil ganglia. In the past, there have been some studies of alkali and alkali-surfactant flooding of heavy oil systems as well, and it has been observed that chemical injection can lead to improved oil recovery. The heavy oil recovery mechanism proposed in this work is the creation of oil-in-water emulsions, which may form under conditions of low interfacial tension and shear due to flow through rock pores. Oil may either be produced in the water (emulsification and entrainment) or the droplets may coalesce or plug the rock pores, leading to improved sweep efficiency (emulsification and entrapment). Both of these mechanisms are investigated in laboratory systems of varying rock permeability, using a heavy oil with a viscosity of 11,500 mPa center dot s. When oil-in-water emulsions form, the oil recovery can be improved significantly, even without the addition of polymer for mobility control. The effect of permeability and varying injection rates are considered, to understand how different ranges of shear affect the efficiency of these emulsion systems.