use of fe3o4 nanoparticles for adsorption of asphaltene from heavy and ultra-heavy materials: a molecular dynamics study

The asphaltene precipitation around the wellbore will result in formation damage, leading to a positive skin factor and an excess pressure drop. conventional treatment methods of asphaltene precipitation are expensive and face limitations. thus, the prevention of asphaltene precipitation is a much better solution. in recent years, there has been a growing interest in using nanoparticles (nps) for asphaltene adsorption. due to the unique properties of nps in asphaltene adsorption (such as high surface-to-volume ratio and high adsorption tendency), they can inhibit the precipitation of asphaltene in the porous media. this research employed molecular dynamics simulations to examine the influence of fe3o4 nps on the adsorption of asphaltene from heavy and ultra-heavy materials. based on the results, increasing fe3o4 nps concentration from 2.5 to 7% raised the diffusion coefficient from 0.51 to 0.61 å²/fs and the mean square displacement (msd) from 4.99 to 5.33 å². however, further increasing the concentration to 10% resulted in a drop in the diffusion coefficient to 0.53 å²/fs and a decrease in msd to 5.06 å². the maximum density profile of atomic structure rose from 0.0049 to 0.0055 atoms/å³ at 7% concentration, but decreased to 0.0051 atoms/å³ at 10%. finally, the asphaltene adsorption rate improved from 72 to 79% as the concentration increased from 2.5 to 7%, but then dropped to 73% at 10%. these results highlight the optimal np concentration for enhancing asphaltene adsorption without causing agglomeration issues.