Molecular dynamics simulations of oil components at geological conditions

Abstract

Modern methods of computational chemistry, including molecular dynamics and quantum mechanics of molecular systems, allow one to obtain accurate values of structural parameters and physicochemical properties of complex systems for a wide range of temperatures and pressures without resorting to experiment. In this work, we explore the effects of physical conditions on densities and viscosities of typical petroleum components, including hexane, octane, dodecane, and octadecane, for temperatures and pressures ranging from ambient conditions (298 K, 1 bar) to geophysical conditions of the upper mantle (2000 K, 60 kbar). Theoretical results are compared with the experimental data and show good agreement in the case of densities and somewhat poorer agreement for viscosities (diffusion coefficients).

Keywords:

• hydrocarbons
• molecular dynamics
• density
• diffusion coefficients
• high pressures

Acknowledgements

Financial support by the Natural Sciences and Engineering Council of Canada and by the University of the Fraser Valley is gratefully acknowledged. We would also like to acknowledge the use of the computational resources of WestGrid.