  The primary objective of this study is to establish an understanding of the
role of high-salinity brine on the intensity of asphaltene aggregation onset
during waterflooding of petroleum reservoirs. We already have shown that
asphaltenes have a high tendency to form aggregates during waterflooding
process when pure- and low salinity-water are injected into reservoirs. To
fulfill the present objective, molecular dynamic simulations are performed on
asphaltenic-oil/aqueous systems. The oil phase consists of asphaltenes and
ortho-xylene, in which asphaltene molecules are completely soluble. Our
simulations results reveal that the salt-in effect of high-salinity brine on
seven different model asphaltenic oils causes a significant reduction of the
onset of asphaltene aggregation as compared with pure-water. Such salt-in
effect is primarily due to a considerable reduction of water miscibility in the
oil phase at high pressure and temperature.
