Precise determination of isentropic exponent and speed of sound in hydrocarbons and natural gases

Summary

This project made accurate speed of sound measurements, both in hydrocarbon gas mixtures prepared by the Groupe Europeen de Recherches Gazieres (GERG) and in locally supplied natural gases at the conditions of temperature and pressure encountered in the North West Shelf gas processing industry.

These direct measurements form the basis for development of an accurate (0.1% on speed of sound) composition-based, wide-range equation of state for natural gas mixtures.

The principles and techniques of measurement are described, including an acoustic resonance technique for precise speed of sound measurement. The results are fully tabulated and their practical application is discussed.

Keywords: North West Shelf gas, isentropic exponent, acoustic resonance, equation of state