Measurement of the (pressure, density, temperature) relation of Ekofisk natural gas in the temperature range from 273.15 to 323.15 K at pressures up to 8 MPa

Abstract

Comprehensive ( p, ϱ, T) measurements on natural gas from the Ekofisk field (North Sea) have been carried out in the temperature range from 273.15 to 323.15 K at pressures up to 8 MPa. The accuracy of the density measurement itself is better than ±0.03 per cent or ±0.003 kg·m −3, whichever is greater. The total uncertainty of the density including the experimental uncertainties of the single measurements of p, ϱ, and T, and the uncertainty of the composition of the gas is less than ±0.1 per cent or less than ±0.003 kg·m −3, whichever is greater. Comparisons with experinental results of previous workers are presented. Furthermore, the new ( p, ϱ, T) values are compared with two current equations of state for natural gas and with a modified version of the AGA-NX-19 correlation method; the deviations range up to 0.2 per cent.