The purpose of this study has been twofold. First, by employing radial disks, the effect of flow geometry found in a field application has been incorporated into the experimental study. At the same time, the ultimate measure of preflush effectiveness, the incremental oil produced as a result of the pretreatment, has been chosen as the yardstick for comparison. Second, by combining the scope of several previously reported studies covering a few inorganic and organic preflush chemicals into one study with a single source of rock, the effect of substrate variability could be isolated from the analysis. This work in Berea is considered a foundation for similar studies to be compJeted in reservoir rock, where the effect of different clay compositions and rock heterogeneities can be compared to the standardized case with Berea sandstone.