Abstract: A method for improving the increasing the efficiency of an unconventional oil recovery (UOR) process uses biodiesel as a surfactant in water-surfactant emulsions or water-solvent-surfactant emulsions for purposes of water-surfactant emulsions flooding or water-solvent-surfactant emulsions methods. A polymer may be added to the emulsions to increase the emulsion viscosity. Water-surfactant emulsions flooding or water-solvent-surfactant emulsions flooding methods may be implemented in intervals alternating with or sequential to intervals of water-only flooding.

Abstract: Methods and systems for treating oil sands tailings streams at an elevated pH using lime are disclosed herein. In some embodiments, the method comprises providing a tailings stream including 10-55% solids by total weight, increasing the pH of the tailings stream by combining the tailings stream with lime to produce a lime-tailings mixture having a pH of at least 11.0, and dewatering the lime-tailings mixture to produce a first stream having 10% or less solids by total weight and a second stream having 50% or more solids by total weight. The first stream can correspond to a release water stream, and the second stream can correspond to a cake. The lime slurry can include about 10% lime by total weight, and can comprise lime hydrate, quicklime, or a combination thereof. Dewatering the lime-tailings mixture can include routing the lime-tailings mixture to a centrifuge unit and/or a pressure or vacuum filtration unit.

Abstract: In a process for destabilizing bitumen-water emulsions to facilitate bitumen recovery therefrom, bitumen-water interfacial tension is increased by reducing or eliminating the activity of functional groups acting as surfactants by treating the emulsions with one or more additives of ionic base to increase the hydrophobic characteristics of bitumen droplets in the emulsions and thus increase their attraction to each other and to gas bubbles. Additives effective for this purpose include salts of the Periodic Table's Group II earth alkali metals cations such as magnesium, calcium, strontium, and barium, and Group III metals cations such as aluminum. Mechanical agitation or injection of a gas stream into the destabilized bitumen-eater emulsion may be used to form bitumen-rich froth. The additives used for destabilization of the emulsions also promote flocculation of clay-size particles in the froth and improve the chemistry of the recovered water.