Estimations of apparent relative permeabilities considered distribution of saturation

This paper describes a new interpretation for relative permeabilities obtained by the experimental data already reported. This estimation of apparent relative permeabilities is based on a pre-determined distribution function of saturation. The conclusions are as follows: (1) The relations between saturation and the apparent relative permeabilities of wetting and non-wetting phases depend not only on the average of saturation, but also on the standard deviation. Journal of the Geothermal Research Society of Japan Vol. 11, No. 4 (1989) (2) The apparent relative permeabilities are conspicuously larger than those calculated by the arithmetical average value of saturation, when the standard deviation of saturation is larger than about 0.2. (3) When distribution functions of saturation have single peaks and their average and standard deviation are fixed, the apparent relative permeabilities based on those distribution functions have almost the same value. (4) The distribution function with two or more peaks may yield apparent relative permeabilities lager than those obtained using the function with a single peak. (5) If Corey type equations are used to describe relative permeability curves, nonlinear relations between the apparent relative permeabilities and saturation are obtained in all cases.