A New Forecast Model and Chart for Natural Gas Compressibility Factor

Gas compressibility factor for natural gas system can be determined from Standing and Katz charts using the pseudo critical gas pressures and temperatures. This chart gives accurate values for gas compressibility factor. Reservoir simulation softwares need accurate correlation to estimate the values of this natural gas property, one of the famous correlations is Beggs and Brill. This correlation gives large errors at high gas reservoir pressure. Old correlations give good estimation of gas z factor at low gas reservoir pressures below 6000psia, at high pressures the error starts to appear. In this study, a new accurate gas compressibility factor correlation has been developed which specifically addressed the limitation of other correlations. The equation was developed by regressing 645 data points of measured gas z factor data point from Niger Delta using Matlab. The d