Effect of the rock dimension on surfactant imbibition rate in the Middle Member of Bakken: Creating a model for frac design

Although oil recovery was low during brine imbibition into the oil-wet cores, alkali/surfactant solution recovered approximately 30-45% of the oil based on the laboratory results. We found higher oil recovery factor was achieved from surfactant imbibition more than just used brine. As would be expected, a given level oil recovery was reached faster in shorter cores than in longer cores in same diameters. The shorter core has a larger ratio of surface area to volume. A model which describes the relationship between Peak Oil recovery and surface areas for cores was derived.