Interfacial Areas in Athabasca Oil Sands
Mohammadmoradi, P., Taheri, S., Kantzas, A.
Energy & Fuels, 31(8), June 2017.
Determination of interfacial areas is crucial for accurate identification of multiphase subsurface flow processes, e.g. in situ water treatment, contaminant transport, phase change, convection/ diffusion, and colloid adsorption/ desorption/ migration. Pore-scale imaging and simulation techniques provide an appealing opportunity to explicitly predict such geometrical characteristics of saturated and unsaturated porous media. Here, synthetic unconsolidated sand packs in a wide range of grain arrangements and size distributions are reconstructed to extensively capture all possible heterogeneous pore-level geometries in the McMurray formation, the primary bitumen formation in the Athabasca oil sands deposit. Multi-phase fluid occupancies throughout the partially saturated media during drainage and imbibition are predicted applying a direct pixel-wised pore morphological model, incorporating wetting phase layer covering rock/solid surfaces. The post-processing results are verified using two-phase experimental data points and images, demonstrating a remarkable variation of the interfacial area as a function of saturation profile, rock configuration, and displacement scenarios. Empirical models are proposed to predict the bulk and meniscus areas using average particle diameter and porosity as input parameters.