Study of asphalt/asphaltene precipitation during addition of solvents to West Sak crude

Based on experimental evidence, it is concluded that (1) Asphaltene precipitation results in removal of heavier fractions of the crude leaving behind lighter deasphalted crude. This indicates that in a miscible process, the alteration of crude composition needs to be accounted for in prediction of phase behavior, compositional path and miscibility conditions for solvent-oil systems. (2) The amount of asphalt precipitation increases with decrease in molecular weight of normal paraffinic solvents. (3) Increase in solvent/oil dilution ratio increases the amount of asphaltene precipitation until a certain dilution ratio after which it levels off. The data gathered in this study will be useful to determine solubility parameters used in the Flory-Huggins Polymer Solution theory coupled with equation of state based phase behavior prediction algorithm to predict amount of asphaltene precipitation at reservoir conditions for West Sak crude-solvent mixtures.