Experimental Verification of Methods to Calculate Relative Permeability Using Capillary Pressure Data

Abstract

Abstract The Brooks and Corey model has been accepted widely to calculate relative permeability using capillary pressure data. However the Purcell model was found to be the best fit to the experimental data of the wetting phase relative permeability for the cases studied, as long as the measured capillary pressure curve had the same residual saturation as the relative permeability curve. The differences between the experimental and the Purcell model data were almost negligible. A physical model was developed to explain the insignificance of the effect of tortuosity on the wetting-phase. For nonwetting phase relative permeability, the model results were very close to the experimental values in drainage except for the Purcell model. However, calculated data in imbibition were different than the experimental data. This study showed that relative permeability could be calculated satisfactorily by choosing a suitable capillary pressure technique, especially in drainage processes. In the reverse procedure, capillary pressure could also be computed once relative permeability data are available.