Accurate predictions of heavy oil and bitumen viscosity as a function of temperature, pressure, and composition are required for the design of thermal and solvent based recovery methods. In this case study, the applicability of the recently developed Expanded Fluid viscosity correlation is tested on measured viscosities of diluted dead and live bitumen at temperatures from 20 to 175°C and pressures up to 10 MPa. The data were collected for: 1) an Alberta bitumen, 2) a condensate, 3) diluted bitumen with 3, 6 and 30 wt% condensate, 4) live bitumen, and 5) diluted live bitumen with 3 and 5.9 wt% condensate. The live oil viscosity was 820 mPa.s at 50°C and 2.5 MPa compared with a dead oil viscosity of 3180 mPa.s.

The Expanded Fluid (EF) viscosity correlation relates viscosity to density at any given pressure and temperature; it requires three parameters for each fluid. In this study, the dead bitumen and the condensate solvent are treated as single components and the viscosity correlation parameters are determined by fitting viscosity data. The parameters for the solution gas, live bitumen, and the bitumen-solvent mixtures were determined from mass based mixing rules. The parameters for the pure components that made up the solution gas were previously determined.

The correlation was fitted to dead Alberta bitumen and the condensate with average relative deviations of 11% and 1.5%, respectively. The viscosity of the live bitumen was predicted to within 20% and 28% of the measured value based on measured and calculated mixture densities, respectively. Diluting the live and dead bitumen with 3 to 30 wt% solvent reduced the viscosity by one to three orders of magnitude and the viscosities were predicted with an average relative deviation under 16 and 37% based on measured and calculated mixture densities, respectively.

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