This work provides a review of and answers the critical question about the optimum wettability for oil recovery through conventional and low salinity waterflooding (LSW) methods. As the answer is not straightforward, this work investigates conflicting views that justify conclusions and provide comparisons between different rock types and conditions. Parameters affecting oil recovery are linked to wettability to identify the optimum state for different waterflooding schemes.
Relying solely on core-based analysis or any other method is argued to be inconclusive without considering the conditions of core handling and testing, pore-network structure, contact angle tests, and field-scale considerations. Therefore, optimum wettability for oil recovery is a multivariate question; thus, comprehensive conclusions should come from cross-factor analysis rather than isolating certain factors. This work provides a reference for researchers to approach this dichotomy through an overview of previous works in this area.