Equation of state analog correlations for the viscosity and thermal conductivity of hydrocarbons and reservoir fluids

Based on the geometric similarity of P–V–T, T–μ–P and T–λ–P diagrams, viscosity (μ) and thermal conductivity (λ) data of hydrocarbons and their mixtures have been successfully correlated using a cubic equation of state (EOS) type equation. The advantages of using EOS-analog expressions are simple in form, applicable to both gas/liquid, high-pressure/low-pressure, and smooth phase transition of μ and λ in the near-critical region could be achieved. First, a modified viscosity correlation based on PR (Peng–Robinson) EOS type expression is presented, which improves the prediction of the viscosity of reservoir fluids (including CO2-injected enhanced oil recovery systems). Then, the development of EOS type expression for fluid thermal conductivity is described. The results of extensive tests with data indicate the superiority of the proposed EOS-analog viscosity and thermal conductivity correlations over typical empirical and semi-empirical correlations used in the petroleum industry.