Predicting Volumetric and Transport Properties of Sour Gases and Gas Condensates Using EOSs, Corresponding State Models, and Empirical Correlations

Abstract

Compressibility, density, and viscosity of natural gases are necessary in most petroleum engineering calculations. Some of these calculations are gas metering, gas compression, design of processing units, and design of pipeline and surface facilities. Properties of natural gases are also important in calculation of gas flow rate through reservoir rock, material balance calculations, and evaluation of gas reserves. Usually the gas properties are measured in laboratory. Occasionally, experimental data become unavailable and these properties are estimated from equations of state, corresponding state models or empirical correlations. This article presents the results of using various equations of state, corresponding state methods, and correlations to predict the volumetric and transport properties of sour gases and gas condensates. Capabilities of PR-EOS, SRK-EOS, and PT-EOS to predict gas compressibility and density of 2100 gas samples under various schemes of binary interaction number are thoroughly investigated. This study also reports a comparison between recently developed EOS-based viscosity models and other methods to estimate the viscosity of highly sour gases and rich gas condensates.