Computational Insights into Temperature and Pressure Effects on Asphaltene Adhesion: Molecular Dynamics Approach

The initial temperature and pressure significantly influence the adhesion process of asphaltene molecules in the petroleum industry. These effects are critical because they impact asphaltene solubility, precipitation, aggregation, and ultimately deposition, which can lead to flow assurance challenges like pipeline fouling and wellbore plugging. In this computational study, the Molecular Dynamics (MD) approach is implemented to describe the effect of temperature and pressure variation on the adhesion process of asphaltene molecules. For this purpose, the temperature changes from ۳۰۰ to ۴۰۰ K, and the pressure varies from ۱ to ۴ bar. The current simulation outputs can be used in practical petroleum industry-based applications. MD simulations are conducted in two main phases. Firstly, the equilibrium phase of the designed system is run for ۱۰ ns with an isothermal–isobaric (NPT) ensemble, and the convergence of temperature/potential energy changes in this phase indicates the equilibrium behavior of the atomic system. Numerically, the potential energy converging to a constant value (۱۵.۰۰ kcal/mol.atom) indicates the attraction force between particles in various regions of the designed atomic system. Next, the adhesion process of asphaltene molecules is simulated with a canonical (NVT) ensemble. Final MD results indicate that the initial temperature and pressure changes cause the size of adhesive asphaltene molecules to increase and decrease, and the gyration radius of this system reached ۴۹.۴۳ and ۴۸.۷۸ angstroms after ۱۰ ns at ۴۰۰ K and ۴ bar. Structurally, decreasing temperature and increasing pressure caused the stability of asphaltene molecules to increase. This structural output highlights the significant effect of the initial conditions on the adhesion process of asphaltene-based systems, which should be considered in the petroleum industry to increase the efficiency of various procedures such as the extraction process, purification, etc.

کلیدواژه ها:

Adhesion ، Asphaltene ، molecular dynamics ، Pressure effect ، Structural stability ، Temperature effect