Development and evaluation of a modified experimental apparatus for phase behavior study of solvent–heavy crude systems

One of the main challenges in the phase behavior study of heavy crudes such as bitumen and solvent systems is the long equilibration time. The equilibration time depends on the experimental conditions, such as pressure and temperature, as well as solvent and oil properties. Oil viscosity is the key factor for the equilibrium time especially at low temperature approaching reservoir condition where the oil viscosity (e.g. Athabasca bitumen) is in the order of million centipoises. Thus, a method to speed up the phase behavior experiments for heavy crudes is essential. The proposed experimental apparatus in our previous study [7] was modified. The modification speeds up generating the experimental data with the capability of conducting parallel experiments. Thus, two or three experiments can be conducted at the same time period. Total cost for this apparatus is almost the same as our pervious apparatus while more experimental data can be produced with this new design. In addition to heavy crude/solvent systems, the proposed apparatus has the capability of conducting the experiments for simple binary systems. The new apparatus was tested for the saturation pressure measurement of pure hydrocarbon, the phase behavior study of simple binary systems, and the phase behavior study of Athabasca bitumen/solvent systems (solvents: methane, ethane, and propane) in the case of vapor–liquid and liquid–liquid equilibrium conditions.

► A new phase behaviour apparatus for heavy crude-solvent systems is described.
► The apparatus speeds up generating experimental data.
► Proposed apparatus has capability for conducting experiments for binary systems.
► Comparison of generated results with literature values verifies quality of apparatus.
► Data for bitumen saturated with methane, ethane, and propane at different temperatures.