show the contact angle for samples from formation A, non-heated and heat-treated at 450°C and 650°C, respectively. The results suggest that non-heated kerogen sample from formation A is hydrophilic with a low contact angle of 44°. As the heat-treatment temperature increases to 450°C, the contact angle of kerogen increases to 107°. Furthermore, as the heat-treatment temperature increases to 650°C, the water droplet forms a sharp kerogen/water/air contact angle of 122° indicating that the kerogen surface is hydrophobic.