Molecular simulation studies on kerogen often use a slit graphite model, which consists of stacked sheets of graphene, to represent kerogen pores in organic-rich shale reservoirs ; Ambrose 2012; Diaz-Campos 2014; Pitakbunkate et al. 2017). However, these models do not capture the complexity of kerogen structure adequately. Moreover, kerogen's crystal structure and oxygen-containing functional groups could have significant impacts on its wettability. used an inactivated kerogen model, which is composed of graphene sheets to represent highly mature kerogen. In order to simulate the effect of thermal maturity, they embedded varying amounts of carbonyl (C=O) functional groups on these graphene sheets to model different oxygen to carbon (O/C) ratios. Wettability studies on these simplified models showed that kerogen is water-wet at low thermal maturities and hydrophobic at high thermal maturity ). However, simplified models for kerogen were used for this study which does not capture the complexity and heterogeneity adequately. Moreover, this study does not consider the impact of oxygen functional groups such as carboxyl or hydroxyl and sulfur-and nitrogen-based functional groups, which are commonly found to exist in kerogen structure. The effect of temperature and pressure on kerogen wettability is also not considered.