Viscosity of cold lake bitumen and its fractions

New data are presented for the effect of temperature on the viscosity of bitumen fractions, which were obtained by vacuum distillation of a large Cold Lake bitumen sample. The viscosity of these fractions differs by several orders of magnitude; from 4.3 mPaϵs for Cut 1 to 430 000 mPaϵs for Cut 4 at 30°C. Cut 5 is a glass‐like solid at room temperature with a softening temperature of about 100°C, and has a viscosity of 800 000 mPaϵs at 120°C. The effect of temperature on the viscosity of each bitumen fraction is modelled very well with a two‐parameter correlation that was shown to be valid generally for Alberta bitumens. The results of bitumen viscosity calculations, based on a simple liquid‐mixture viscosity formula, are presented and compared with the bitumen viscosity data.