The oil slick is brighter than the surrounding water in some places (image centre) and darker than the surrounding water in others (image lower right).

This paper mainly describes the universality of water contained in fuels, the actions of water and its heat loss in the fuels, and the essentiality of emulsification of the oil-water mixture.

In the post-water flooding process, WG in the larger channels diverts the injected water entering the smaller pores and displacing residual oil to form oil bank in the front of the displacing water.