Magnetic treatment of petroleum and its relation with asphaltene aggregation onset (an atomistic investigation)

Magnetic treatment is often used in certain oil industries for alterations in petroleum rheological properties. In this report, we introduce the scientific basis for the role of magnetic treatment on the onset of asphaltenes aggregation from petroleum fluids. Molecular dynamics simulations are used to study the effect of magnetic fields that are applied to three different model asphaltenes (A1-A3) in paraffinic and aromatic oil media. Radial distribution functions, hydrogen bond interactions, and the simulation trajectories are produced and analyzed. Our simulation results show that the onset of asphaltene aggregation in petroleum fluids is affected by the magnetic field and it is a function of its strength. In a paraffinic medium, magnetic field reduced aggregation of the model asphaltenes studied in the range of 20-35%. Where magnetic field of 1.5T caused a high disruption of A1 aggregation and changed the dominated stacking. However, the highest disruption of A2 and A3 asphaltenes was at 1.0T. In an aromatic medium, magnetic field reduced association of the model asphaltenes studied in the range of 25-70%. Where 0.5T diminished the association of A2 and A3 asphaltenes while 1.0T was able to do that for A1 asphaltene. The stacking modes and distances between asphaltene molecules were also affected by magnetic field. For example, in paraffinic medium, 0.5T enhanced the aggregation of A1 and A2 asphaltenes with multiple-layer stacking where some of the peaks appeared farther than the reported cutoff of asphaltene stacking. Hydrogen bond results showed that magnetic fields did changes on the average number of hydrogen bonds. These changes were due to changes in the orientation and the distances between asphaltene molecules. The difference in asphaltene response to the magnetic treatment was due to the differences in their structures. Overall, the effect of magnetic field on the onset of asphaltene aggregation is dependent on the magnetic field strength, asphaltene architecture, and the medium. Results of this simulation are applicable to asphaltene behavior in real crude oil.