Molecular Insights into Asphaltene Aggregation in Gas Flooding

The gas flooding has been well developed and been widely used for heavy oil recovery. The extraction of light oil components by injecting gas with supercritical properties could destroy the stable asphaltene colloidal structure and induce asphaltene aggregation and precipitation, which greatly threatens reservoir permeability and wellbore safety. In this work, employing molecular dynamic simulations, the asphaltene aggregation behavior in gas flooding was investigated. Three kinds of injecting gases, CO2, CH4, and C3H8, and three temperatures at 350, 410, and 470 K were adopted to study the effects of injecting gas types and temperature on asphaltene aggregation. Simulation results indicate that the asphaltene aggregation degree is high in CO2 flooding, and it increases with decreasing temperature. Furthermore, the spatial structure and intermolecular interaction were discussed to unveil the underlying mechanism of asphaltene aggregation. This work reveals molecular-level insights of asphaltene aggregation in gas flooding under different temperature, which is expected to facilitate future studies on controlling asphaltene precipitation in gas flooding.

Automated summary

This study investigated the behavior of asphaltene aggregation in gas flooding using molecular dynamic simulations. The results showed that the degree of asphaltene aggregation is high in CO2 flooding and increases with decreasing temperature, providing insights into controlling asphaltene precipitation in gas flooding.