Molecular dynamics simulation of PVT properties of geological fluids and a general equation of state of nonpolar and weakly polar gases up to 2,000 K and 20,000 bar

The PVT properties of CH[sub 4] from 30-360 cm[sup 3] mol and roughly from 273-2,000 K and from 100-20,000 bar have been simulated by molecular dynamics using Lennard-Jones potentials. The simulated results compare with data within 1.5% in volume. Using these simulated values and experimental PVT data, an equation of state (EOS) was developed. Because of the choice of potential, a simple scaling generalizes the EOS to predict the supercritical PVT properties of CO[sub 2], N[sub 2], CO, H[sub 2], O[sub 2], and Cl[sub 2] within an average error of about 1.5%.