Aggregation behavior of various component in crude oil for insight of aquathermolysis technology application

• Aquathermolysis technology consumes huge energy during the application process. • The deeper insights into the application of aquathermolysis technology have been gained. • The total intermolecular interactions are dominated by π-π interactions within the conjugated skeleton structure. • Aquathermolysis can effectively reduce fused conjugated skeleton in resins. • Aquathermolysis technology is recommended for high oils with high resin content. Aquathermolysis is a promising technology for enhancing heavy oil recovery by breaking heavy component into smaller molecules and reducing its viscosity. To gain deeper insights into the application of aquathermolysis technology, seven crude oil models with different viscosities were established through molecular dynamics (MD) simulations, in this paper. The noncovalent weak intermolecular interactions related to viscosity among different components were computed using density functional theory (DFT). Then, the contribution of different types of complexes to total intermolecular interactions was investigated. It is found that total noncovalent weak intermolecular interactions are mainly caused by the strong π-π interactions on the aromatic skeletons of aromatics, resins and asphaltenes. For the aquathermolysis reaction, there is still large interaction energy of asphaltene-asphaltene complexes. Therefore, this technology is recommended for initial application in high viscosity oils characterized by excessive resin content and low asphaltene content.