Asphaltenes aggregation during petroleum reservoir air and nitrogen flooding

Aggregation onsets of seven different asphaltenes dissolved in model oils, due to the effects of misciblized compressed air or nitrogen injections, were studied through molecular dynamics simulation. Natures of aggregations, cumulative coordination numbers, and interaction energies were investigated. Onset of aggregation processes were highly affected by injected gas concentration. In more cases little differences were observed between using air and pure nitrogen. However, asphaltene aggregation onset was highly affected by its molecular architecture. Asphaltenes with long aliphatic chains and archipelago structure showed low aggregation affinities.