New correlations for water content of sweet and sour natural gases

The water content of natural gas is very important for gas pipeline operators. This paper developed an improved correlation model which is easy-to-use and with an appropriate accuracy to predict the water content of both the sweet and sour gases. The new correlations are generated from the Wang correlation combined with the Keenan-Keyes model. The temperature correction terms as well as the CO2 and H2S ones were introduced to this method for a better accuracy. The limited experimental data validate the new correlations are applicable for the natural gas with the mole fraction of CH4 > 70%. The sweet gas correlation is valid from –2°C to 100°C and 0.49 MPa to 13.79 MPa. The sour gas correlation is valid from 34°C to 71.11°C and 2.47 MPa to 13.79 MPa for gas mixture when CO2 < 20% and H2S < 29%. The average relative deviation between literature and correlation values for sweet gas is 3.03%, and that for sour gas is 4.44%.