Petroleum seep is a natural occurrence where petroleum (also known as crude oil) is released to the surface of the earth from underground reservoirs.
This can happen through cracks or fractures in the rock formations that contain the petroleum, or from natural openings in the ground such as fissures or wells. Petroleum seeps are often characterized by the presence of a thin film or sheen of oil on the surface of the ground, or by the presence of oil droplets or “tarballs” on the ground or in water bodies. Petroleum seeps can also produce gases, such as methane, that can accumulate in underground pockets or be released to the surface.
In some cases, petroleum seeps can be exploited as a source of oil, but in other cases, they may be considered a nuisance or environmental hazard.