Calculate Water Content of Natural Gas with Excel

This Excel spreadsheet calculates the equilibrium water content of natural gas.  It uses a correlation derived from the McKetta-Wehe chart.  Originally published in 1958, the McKetta-Wehe chart is widely accepted in the natural gas industry.

There are several restrictions inherent to the McKetta-Wehe chart.
  • This chart is suitable for sweet natural gas with a mole fraction of methane of more than 70%, and a relatively small fraction of heavy hydrocarbons. 
  • Water content is overestimated at pressures of 70 bar absolute and over.
  • The correlation is not suitable for natural gas in equilibrium with gas hydrates. The water content of these is a complex function of their composition and time.  Thus few reliable correlations exist, and thermodynamic models are usually used.
  • The McKetta-Wehe chart should only be used at temperatures below which hydrate would form.
Download Excel Spreadsheet to Calculate the Water Content of Natural Gas