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.