investigation of reversibility of asphaltene precipitation and deposition for an iranian crude oil

in this work, the precipitation and re-dissolution of asphaltenes were studied for an iranian relatively heavy crude oil. a series of experiments were designed and carried out to quantitatively examine the reversibility of asphaltenes precipitation upon the change in the solvent concentration along with the temperature. n-heptane was used as the precipitant, and a temperature range of 30 to 70°c was applied to perform the temperature reversibility tests. experiments were conducted in both porous and non-porous media. as a porous medium, a slim tube apparatus was used which is a one- dimensional model reservoir. generally, the experiments showed that the precipitation is completely reversible for oil under study upon both composition and temperature changes.