Reaction Molecular Dynamics Study of Combustion Mechanism in Heavy Oil Thermal Recovery

The organic material present at the same depth as the oil in the reservoirs has the potential for conversion, as indicated by analyses conducted before and after heavy oil combustion. Therefore, in this study, we examined the oxidation and pyrolysis reaction pathways of hydrocarbons, specifically benzaldehyde (C₇H₆O) and naphthalene (C₁₀H₈), before and after combustion using molecular dynamics simulations. The results showed that the primary products formed under various temperature conditions included H₂O, HO₂, CO, and CO₂. We determined the number of molecules, such as HO and H, as well as their temperature variations, and found that the activating group functions as an electron donor, while the inactivating group serves as an electron acceptor. The oxidation and pyrolysis reactions of naphthalene and the synthesis pathway of benzaldehyde were also explored. C-C dissociation in the early stages of combustion and the process of C-C bond synthesis in the later stages of the reactions were investigated through dynamic simulations at different temperatures, 3000 K, 3500 K, and 4000 K, with a particular focus on the reaction network at 4000 K. The application of the molecular reaction dynamics method to heavy oil combustion research was the primary objective of this work. This study aims to provide a novel approach to investigating hydrocarbon conversion at high temperatures and offer recommendations for enhanced oil recovery.