Molecular interaction between asphaltene and quartz with different surface wettability: A combined study of experimental measurement and theoretical calculation

There is a limited understanding with respect to the relationship between asphaltene adsorption/deposition and surface wettability at a molecular level, which could lead to a serious restriction of the development of heavy oil recovery techniques. In this study, the adsorption behavior of a model compound asphaltene (C5Pe) and the detachment process of C5Pe during waterflooding were investigated in different wettability conditions. Both experimental and simulation results indicate that: i) C5Pe molecules tend to adsorb onto hydrophilic surface with the adsorbed mass (AM) being about 114 ng/cm(-2) and in a tilted configuration, assigned to the hydrogen bonding interactions between polar groups of C5Pe molecules and -OH groups on hydrophilic surface; ii) C5Pe molecules are difficult to be adsorbed on hydrophobic surface with a preferential parallel orientation and the AM is only 62 ng/cm(-2), because of the loose and flexible adsorbed layer, resulting in a high potential of asphaltene desorption for the hydrophilic surface. Our research results may provide a reasonable explanation for the molecular mechanisms improving the low-salinity effect on asphaltene stripping from rock surface, which could open a promising avenue for various application fields.