Combining Production History and Petrophysical Correlations to Obtain Representative Relative Permeability Data

ABSTRACT Prediction of gas reservoir performance under water drive is very sensitive to relative permeability data. Gas-water relative permeability ratio (Kg/Kw) at different values of water saturation (Sw) can be derived from production history. This technique provides data considered the most representative of reservoir characteristics since it reflects actual reservoir performance. However, the developed (Kg/Kw) vs Sw curve is only valid in the higher range of water saturation and in the absence of water coning and other forms of water intrusion. The valid portion of the curve can be used to calibrate a generalized correlation. The calibrated correlation is then used to derive relative permeability data over the entire water saturation range. The technique discussed can also be applied to oil-water systems.