Molecular insights into the dispersibility of asphaltene and crude oil rheological properties under the effect of multi-alkylated aromatic amides

Abstract

In crude oil development, it is important to improve the dispersibility of asphaltene (ASP), and to achieve viscosity reduction. Adding dispersants is a promising solution to postpone the ASP deposition, nevertheless, the effect of dispersants to the oil viscosity is at odds. To provide insight into the role and mechanisms of ASP dispersants in regulating the dispersibility of ASP and the oil rheological properties, we performed computational simulation studies. It is demonstrated that MAA dispersants adsorb onto ASP clusters via the polar interaction, isolating ASP clusters and preventing further aggregation. In addition, dispersed ASP molecules present stronger intermolecular friction with light-weighted components and the hydrogen bond spatial network can be enhanced, thereby leading to the increase of oil viscosity. These molecular insights help to understand the association of crude oil rheological properties with ASP dispersibility, which is expected to facilitate the future development of chemical agents for crude oil recovery.