There exists several methods for wettability quantification including wilhelmy balance method (Wilhelmy 1863), tilting plate method (Adam and Jessop 1925), capillary bridge method (Restango et al. 2009), and sessile drop method ; Yuan and Lee 2013). Among these methods, sessile drop method has become one of the standard and commonly used methods, which we considered as the best option for the kerogen samples in this study. In the sessile drop method contact angle measurement is achieved by measuring the tangent angle at the three phase contact point on a drop profile. The shape of a droplet and contact angle is determined by the intermolecular forces and the surface tensions between the phases involved. The mechanical equilibrium of a drop of fluid on a solid surface is achieved as a result of three surface tensions given via,