Emulsion Flooding of Heavy Oil

Abstract

The goal of this work is to develop alkaline-surfactant methods to improve recovery from a heavy oil reservoir in the north slope of Alaska. Phase behavior experiments were conducted to determine conditions under which oil-in-water emulsions form. The viscosity (and its shear dependence) was measured for some of these emulsions. Reservoir sand was assembled in sand packs. Water flood and alkaline-surfactant floods were conducted at several salinities. Several relatively hydrophilic surfactants were identified which formed oil-in-water emulsions with the reservoir oil at a low concentration in the presence of sodium carbonate. Emulsions formed at low salinity and high oil-water-ratio. Viscosity of these emulsions was relatively low compared to the oil viscosity. Waterflood recovery was of the order of 20-30% PV and it decreased as the injection rate increased. The alkaline-surfactant flood following the waterflood gave an incremental oil recovery of 20-40 % PV. Alkalinesurfactant floods look promising, but the mechanisms of this flood need to be understood to upscale this process to the field.

Amphiphilic Nanohybrid Catalysts for Reactions at the Water/Oil Interface in Subsurface Reservoirs

“…By changing the oil/water ratio and the salinity of the water, different emulsion types (either O-in-W or W-in-O) can be obtained. The rheological and interfacial properties are affected by these changes, which may result in enhanced oil recovery and variations in pressure drop, as measured in sand pack flood studies . Effect of pore blocking and diversion of injection fluids caused by addition of silica nanoparticles have been investigated in multiphase flow experiments in core floods.…”