Wide Range, High Accuracy PρT Measurements by Single Sinker Magnetic Suspension Densimeter for Natural Gas-Like Mixtures

Abstract

This chapter elaborates the high-accuracy density measurement data are necessary to validate equations of state (EOS) used in natural gas transport. The American Gas Association (AGA) AGA8- DC92 EOS, currently the industry standard, has been validated against a databank of gas mixtures with compositions containing up to 0.2 mole percent of the C6+ fraction and should predict densities of natural gas mixtures containing higher mole percentages of the C6+ fraction with the same accuracy. Several attempts have been made to develop a new EOS that can serve the gas industry because the reliability of AGA8-DC92 has been criticized over the past years. One of the biggest reasons that academia seeks opportunities to develop new EOS is the need to express the PρT behavior of natural gas mixtures that contain heavy components in larger fractions than AGA8-DC92 can handle. Production of natural gas streams containing higher percentages of the C6+ fraction has begun recently in North America. High-accuracy, density data for such natural gas mixtures are necessary to check the ability of AGA8-DC92 to cover the entire range of pressure, temperature and compositions encountered in custody transfer.