The present disclosure is directed to a method of determining wettability characteristics of a sub-surface formation within a wellbore utilizing nuclear magnetic resonance (NMR) and bulk fluid measurements at various stages of fluid saturation at that wellbore location. In another aspect, the pumping pressure is incrementally changed within the wellbore, measuring injection fluid and hydrocarbon saturation data values between the incremental pump pressure changes. In another aspect, a measuring and sampling tool is disclosed to execute the method and produce wettability characteristics. In another aspect, a system is disclosed that can operate NMR devices, bulk fluid equipment, pump systems, and other devices to collect data and to determine wettability characteristics on the collected data.