Content (English): Oil shale is a kind of rock containing combustible organic matter with an oil content of more than 3.5%. It is an important unconventional oil and gas resource. It is listed as an important 21st century with its rich resources and feasibility of development and utilization. Replacing energy is also a non-renewable fossil energy source. It is generally believed that oil shale is formed by the deposition of silt, silt and organic matter decomposed by lower biological residues.