Prediction of Asphaltene Deposition Dynamics in Various Microfluidic Geometries Using Computational Fluid Dynamics

Abstract

Despite major advances made in visualization and quantification of the asphaltene deposition process using microfluidic systems, a robust simulation approach complementing empirical efforts to predict asphaltene deposition behavior is lacking. This study developed a novel methodology to simulate asphaltene particles' movement and deposition in different microporous geometries using a two-dimensional computational fluid dynamic. Several configurations of posts were compared to determine the effect of hydrodynamics on asphaltene deposition patterns. The COMSOL Multiphysics v.6.0 software was used to solve fluid flow equations. Two approaches were adopted: one using Newton's equations of motion coupled with fluid flow equations to obtain particle trajectories, and another involving solving fluid flow and species transport equations together with an ordinary differential equation as a boundary flux for asphaltene deposition. As particle tracking simulation is time-consuming, the second approach was chosen to predict the deposition content for longer periods. The second approach could reproduce empirical results and showed that the quantity of asphaltene deposition decreased consistently from the front to the back of a post. The decreases for circular-staggered, square, and rhombus shapes were 0.1914, 0.1676, and 0.0530%, respectively. In the circular-inline configuration, the pattern of asphaltene deposition was different due to hydrodynamic effects. Additionally, most asphaltenes were deposited on diamond-shaped posts after 30 min, around 2.7077 μ g among the porous geometries studied. This study provides a novel approach to predicting the deposition dynamics of asphaltenes and potentially other colloidal systems in a microporous geometry and allows for process optimization under real-practical conditions.