Molecular & Colloidal Structure of Heavy Oil & Tar Mats

Heavy oils and tar mats exploitation, transportation and processing, are largely affected by their high viscosities, that are explained by composition gradients in oil reservoirs [1]. These high viscosities are also related to the presence of asphaltene aggregates [2]. The extent of aggregation mechanisms could explain the tar mat formation. Numerous research programs tend to build the structure-function relations of crude oils by characterizing the molecular organization and the aggregation mechanisms that this organization involves. We present here a combination of small angle scattering and viscosity measurements of asphaltenes in toluene solution, at various concentrations. The detailed characterization of asphaltene aggregates enables to predict solution viscosities as a function of asphaltene concentration, up to the concentrated regime.