Viscometric principles of onsets of colloidal asphaltene flocculation in paraffinic oils and asphaltene micellization in aromatics

Recently, we proposed a new technique for the determination of the onset of asphaltene flocculation.(1) This new method is based on viscosity measurements of a crude oil upon titration with a precipitating solvent (e.g. n-pentane, n-heptane, etc.). The onset of asphaltene flocculation is detected by a sharp increase in the relative viscosity of the suspension in which asphaltene particle aggregation occurs. The key point in this development is the phenomenon of asphaltene flocculation induced by the addition of an n-paraffin hydrocarbon to a crude oil. The proposed method can also be applied to detect the onset of micellization of asphaltenes in aromatic solvents. In this paper, we validate the proposed new technique from a theoretical standpoint.