A Viscosity Correlation for Mixtures of Heavy Oil, Bitumen, and Petroleum Fractions

High viscosity is a major constraint in the recovery and transportation of heavy crudes and tar sand bitumens. Viscosity reduction may be achieved by mixing the crude with a light petroleum solvent. This paper presents a generalized correlation for calculating viscosities of such mixtures. A power-law mixing rule was generalized by use of the Einstein-type relationship for the viscosities of infinitely dilute solutions. Literature and in-house data were compiled to establish the correlation. The final correlation requires only density and viscosity of the two fluids to predict blending viscosity at any mixture composition. The correlation is tested with heavy-oil/solvent blending data and gives an excellent prediction of the blending viscosities.