Compositional Modeling of Crude Oils Using C10–C36 Properties Generated by Molecular Simulation

Owing to the lack of detailed analysis in the C10+ fraction and scarcity of reliable thermodynamic properties on polycyclic compounds, it is usually not feasible to relate crude oil properties with the chemical structure of heavy fractions. Over the last decades, the description of C10–C36 fractions has mostly relied on average Cn properties determined from observations. We propose an alternative approach in two major steps. In the first step, we use Monte Carlo simulation methods to generate vapor–liquid equilibrium (VLE) data on representative hydrocarbons between C10 and C30, from ambient to near-critical temperature. Based on these results, standard liquid density and saturation pressure are correlated for naphthenic hydrocarbons (mono- and polycyclic), aromatic hydrocarbons (monocyclic, polycyclic, and naphthenoaromatic), and thiophenic compounds up to C36. In the second step, we apply the predicted properties on C10–C36 families to model nine real crude oils. The Cn fractions (n = 10–36) are describ...