Analysis of wettability alteration in low salinity water flooding using a zeta potential-based model

: This study introduces a zeta potential-based model which connects low salinity water flooding oil recovery to the reservoir wettability. The model assumed that the reservoir wettability is controlled by the electrostatic forces that exist between rock-brine and oil-brine interfaces. Therefore, it links the wettability to the zeta potentials present at the corresponding interfaces. Using the model, various literature oil recovery data were simulated and then statistically compared the trend of the oil recovery factor with the trend of the wettability indicator values. The Pearson correlation coefficient was used for the statistical analysis. The results from the suggested model were compared with the outputs computed from other pre-existing models for wettability alteration. The simulation outcome indicated that a strong relationship exists between reservoir wettability and the zeta potentials produced at the rock-brine and oil-brine interfaces. The Pearson correlation coefficient calculated for the suggested model exceeded 0.7 for all the experimental cases simulated. However, most of the other pre-existing models showed weak relationships between the wettability indicator values and the oil recovery factor, with some models producing the Pearson correlation coefficient below 0.2. This study highlights the role of zeta potentials at the rock-brine and oil-brine interfaces on the wettability alteration during low salinity water flooding. The suggested model can be utilized in the decision making and implementation of low salinity water flooding works.