The Effect of Wettability on Oil Recovery of Alkaline/Surfactant/Polymer Flooding

Abstract The present paper summarizes the laboratory studies of the effect of wettability on oil recovery of Alkaline/Surfactant/Polymer flooding. The wettability of water-wet Berea sandstone was altered into neutral-wet and oil-wet conditions by using organic reactants. The wettability index of each core sample was determined using a modified Amott imbibition method. The displacement efficiency of Alkaline/Surfactant/Polymer flooding and Polymer flooding at the different wetting conditions was evaluated by laboratory coreflood experiments. The experiment results indicate that the displacement efficiency of water flooding and ASP flooding is markedly affected by the wettability of the core. The wettability is one of the important factors to determine the oil recovery of water and ASP flooding. Water-wet and oil-wet conditions are favorable to obtain high enhanced oil recovery for ASP flooding. Contrast to ASP flooding, the influence of wetttability on oil recovery of polymer flooding was found to be minor for the three different wetting conditions. These results provide a guide to applying the ASP flooding and polymer flooding to the reservoirs with different wettability.