Measurement and modeling of density and viscosity for mixtures of Athabasca bitumen and heavy n-alkane

The viscosity of bitumen is extremely high at ambient temperature and in order to produce and transport the bitumen, it is necessary to reduce its viscosity. One of the methods to reduce the bitumen viscosity is the dilution with liquid solvent. In this manuscript, the density and viscosity of bitumen, tetradecane, and their mixtures at different weight fractions have accurately been measured. The measurements were taken under conditions applicable for both in situ recovery methods and pipeline transportation of heavy oil. The experiments were conducted using Athabasca bitumen and tetradecane at temperatures varying from ambient up to 343 K and at pressures up to 10 MPa on mixtures with 0.05, 0.1, 0.2, 0.3, 0.4, and 0.5 weight fractions of solvent. The generated experimental data for raw bitumen and tetradecane were correlated with the existing correlation models in the literature. The data for the mixtures were also evaluated with predictive schemes as well as with correlation models representing certain mixing rules proposed in the literature. The influence of pressure, temperature, and solvent weight fraction on the density and viscosity of mixtures was considered in the models and evaluated from the experimental results. The density data are reasonably predicted using an equation without adjustable parameter in which it is assumed that no volume change occurs. The viscosity data for the mixtures are well correlated with Lederer's and power law models.