A method and solvent composition for removing viscous crude oil, waxes, asphaltenes and resin precipitates of petroleum origin from oil wells, flow lines and pore spaces of oil-bearing formations. The solvent composition is a mixture of about 45 to about 85 volume percent of a normally liquid aliphatic hydrocarbon boiling in the range of about 120.degree. F. to about 550.degree. F., between about 5 to 45 volume percent of a normally liquid aromatic hydrocarbon, between about 0.5 to about 6 volume percent of an ether of an aliphatic polyhydric alcohol, and between about 1 to about 15 volume percent of a lower alkyl monohydric alcohol.