TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractCalifornia's oil fields are rapidly maturing. Enhanced oil recovery may sustain the life of these fields. Residual oil saturation is one factor in determining the success of enhanced oil recovery projects. Miocene turbidite data from the giant Elk Hills Oil Field, California, illustrate a process to characterize laboratory residual oil saturation tests and approximate values in gravity drainage and waterflooding processes. This characterization will aid in assessing the potential of enhanced oil recovery in California's mature oil fields.