Petroleum geology is the study of hydrocarbon fuels' origin, occurrence, transport, accumulation, and exploration. It refers to a particular set of geological disciplines used in the quest for hydrocarbons (oil exploration). Petroleum geology is the application of general geology to the exploration and development of petroleum resources (petroleum is the collective noun for oil and gas). Because sedimentary basins contain practically all known petroleum reserves, it is centered on their stratigraphy and structure. The term "petroleum geology" refers to a range of geological sciences used in the hunt for hydrocarbons (oil exploration). In sedimentary basins, petroleum geology is primarily concerned with the evaluation of seven important elements: source, reservoir, seal, trap, timing, maturation, and migration.