High Temperature Density, Viscosity, and Interfacial Tension Measurements of Bitumen–Pentane–Biodiesel and Process Water Mixtures

As an alternative to solvent addition to the steam-assisted gravity drainage process for bitumen recovery, coinjection of biodiesel with steam as a surfactant additive to reduce bitumen–water interfacial tension was considered. The density and viscosity of bitumen and bitumen–pentane mixtures up to 15 % pentane concentrations by mass were measured at a 1 MPa pressure and up to 448 K temperature. The interfacial tension between bitumen, bitumen–pentane mixtures up to 15 % pentane concentrations, bitumen–biodiesel mixtures up to 0.3 % and water, and process water was also measured at a 1 MPa pressure and up to 423 K temperature. Laboratory tests showed that the density of bitumen–pentane mixtures decreased linearly with an increase in pentane content, and their viscosity decreased exponentially with the increase in temperature. A decrease in bitumen viscosity with an increase in pentane content was dramatic at low temperatures and became less sensitive at temperatures above 373 K. Interfacial tension measur...