Implementations described and claimed herein provide systems and methods for determining surfactant impact on reservoir wettability. In one implementation, a nuclear magnetic resonance T1 measurement of a sample is obtained before surfactant imbibition is applied to the sample, and a second nuclear magnetic T2 measurement of the sample is made after forced imbibition of the surfactant. Moreover, another nuclear magnetic resonance T1 measurement (e.g., omitting surfactant imbibition) can be obtained simultaneously with the nuclear magnetic resonance T2 measurement using a twin core sample. The nuclear magnetic resonance T1 measurement and the nuclear magnetic resonance T2 measurement are captured under simulated reservoir conditions. A fluid typing map is generated using the nuclear magnetic resonance T1 measurement and the nuclear magnetic resonance T2 measurement. An impact of the surfactant on fluid producibility is determined based on the fluid typing map.