GPA 2172-14
Calculation of Gross Heating Value, Relative Density, Compressibility and Theoretical Hydrocarbon Liquid Content for Natural Gas Mixtures for Custody Transfer
standard by GPA Midstream Association, 01/01/2014
Full Description
GPA 2172-14 presents procedures for calculating, at base conditions from composition, the following properties of naturalgas mixtures: gross heating value, relative density (real and ideal), compressibility factor and theoretical hydrocarbonliquid content which in the U.S. is typically expressed as GPM, the abbreviation for gallons of liquid per thousand cubicfeet of gas.
Rigorous calculation of the effect of water upon these calculations is complicated. Because this document relatesprimarily to custody transfer, the water effect included is an acceptable contractual calculation. Annex A of this standardcontains a detailed investigation of the effect of water and detailed derivations of the equations presented in the standard.