The main thing i dislike is that there are filed where you do not have any presence of water . So the migration of the oil in this fields are not inline with the main theory that first there was a water then oil became and start to displace the water by capillary forces which is a function of density wettability angle and surface tension. But your question is very broad and it ends in the oil bearing mother rocks and open main question - what are the nature of oil is it organic or not organic. I think that you need to emphasize your work on something that then can be implemented in industry rather that stress philosophy. Nothing personal i am an engineer and like to solve problems which then will help others people in there work and i wish you the same. Good luck.