Viscous Oil Recovery Using Solids-Stabilized Emulsions

Abstract

Abstract An overview is given of the development and field testing of a non-thermal, viscous oil recovery technology that injects into a reservoir oil-external solids-stabilized emulsions (SSE) as a displacement fluid. The emulsion is generated on site using produced crude oil and water. Small amounts of added mineral fines are used to enhance the performance of naturally present surface-active components in the oil. Gas is dissolved into the oil to adjust the viscosity of the injected emulsion to be similar to that of the in situ oil. SSE fluid displaces viscous oil in a miscible-like manner with favorable mobility, which leads to to improved displacement and recovery. SSE is generally applicable to reservoirs with in situ oil viscosities of up to approximately 3000 cP and permeabilities on the order of one Darcy or more. A series of laboratory tests were conducted to confirm the effectiveness of solids-stabilized emulsions as displacing agents. Specialized coreflood were used to measure emulsion stability, confirm process understanding, and to determine displacement efficiencies. After lab testing and reservoir modeling, a field pilot of the SSE process was designed, constructed, and operated. The field piloting confirmed the ability to generate and sustain injection of a solids-stabilized emulsion in the field and to propagate stabilized emulsions in the reservoir.