Patent ID: 7579303

Claim:
A method for reducing the viscosity and toluene equivalence of an oil containing asphaltenos comprising the steps of: a) mixing with the oil, a polar solvent and an asphaltene dispersant additive wherein the weight ratio of oil: polar solvent is in the range of 10:0.1 to 10:5, the asphaltene dispersant additive is at a treat rate in the range of 0.025 to 5 weight percent based on the weight of the oil, and then, b) removing at least 90 wt % of the polar solvent from the mixture of oil, polar solvent and the asphaltene dispersant additive to provide upgraded oil with reduced viscosity and toluene equivalence, and c) wherein said polar solvent is selected from the group consisting of chlorinated solvents, liquid CO 2 , liquid SO 2 , liquid H 2 S and mixtures thereof.