Wettability determination of rock samples

A method comprising:

• conducting a primary drainage process on a rock sample;
• conducting a core aging process on the rock sample;
• conducting a water flooding process on the rock sample;
• conducting an enhanced oil recovery (EOR) flooding process on the rock sample;
• conducting a core cleaning process on the rock sample;
• for each of the primary drainage process, the core aging process, the water flooding process, the EOR flooding process, and the core cleaning process:
• measuring an equilibrium sample magnetization distribution across a plurality of locations along a longitudinal length of the rock sample;
• and
• measuring a spatially resolved spin-spin relaxation time spectrum across the plurality of locations along the longitudinal length of the rock sample;
• determining one or more hydrocarbon saturation distributions of the rock sample based on the equilibrium sample magnetization distributions;
• determining one or more wettability distributions of the rock sample based on the spatially resolved spin-spin relaxation time spectrums and the one or more hydrocarbon saturation distributions;
• and
• determining one or more wettability modification factor distributions of the rock sample based on the spatially resolved spin-spin relaxation time spectrums and the one or more hydrocarbon saturation distributions.