Mixing rules for predicting the viscosity of bitumens saturated with pure gases

Mixing rules are developed and evaluated for predicting the viscosity of Alberta bitumens saturated with each of N 2 , CO, CH 4 , CO 2 and C 2 , H 6 . The viscosity‐temperature variation for all bitumens and gases is expressed as [log(μ + 0.8) = ± 10   b   1T   b   2]. A linear cross‐correlation between parameters b 1 and b 2 in the above relationship is identified and used subsequently to derive a one‐parameter viscosity equation: [log(μ + 0.8) = θ(ΦT) b ]. where θ = 160, Φ = 0.008 for all bitumens and θ = ‐0.1, Φ = 0.015 for all gases. The two mixing rules examined in this study are: \documentclass{article}\pagestyle{empty}\begin{document}$ \log \left( {\bar \mu + 0.8} \right) = \sum v_i \,\log \left( {\mu _i + 0.8} \right) $\end{document} and \documentclass{article}\pagestyle{empty}\begin{document}$ \log \left( {\bar \mu + 0.8} \right) = \sum v_i \,\log \left( {\mu _i + 0.8} \right) + \sum \sum v_i v_j B_{ij} $\end{document} , where v represents the geometric mean of mass and mole fractions and B ij is a binary viscous interaction term. Predictions for the viscosity of gas‐saturated bitumens are validated with over 400 experimental data points for five Alberta bitumens at temperatures from 12 to 120°C and pressures up to 10 MPa.