Experimental verification of the applicability of methods for calculating the compressibility factor of natural gas at low temperatures

Abstract

The article is devoted to the analysis of compressibility factor calculation methods in the temperature range from 220 to 250 K. The AGA8-92DC (GOST 30319.2- 96), AGA8 Report Detail (GOST 30319.3-2015), GERG-2004/2008, NX19, GERG-91, ISO 20765-1 (GOST R 8.662-2009), GSSSD MR 118-05 (moderately compressed gas mixtures) and GSSSD MR 113-03 (Wet Oil Gas) methods are experimentally tested.
Deviations of experimental data and calculated values of compressibility coefficient determined by the specified methods are shown. It is found out that the deviation of the calculated values of the compressibility factor according to the AGA8-92DC, AGA8 Report 1 Detail, GERG-2004/2008, ISO 20765-1 (GOST R 8.662-2009), GSSSD MR 13-03 methods from the experimental ones does not exceed 0,1 %. This fact confirms the possibility of using these methods in the temperature range from 220 to 250 K. The results obtained in the framework of this study are highly significant for flow metering, and in particular, provide an increase in the accuracy of the procedure for bringing the volume of natural gas to standard conditions at low temperatures.