Geological characteristics and resources/reserves of oil shale in northwestern China and its exploitation and utilization conditions

Abstract：The total predicted resources and identified reserves of oil shale in northwestern China are at least 40 billion t, equivalent to ~2 billion t of shale oil. The demonstrated reserves are mostly of small or medium size. Oil shale deposits in northwestern China may be classified into the following three types： Mid-Late Carboniferous littoral-neritic sedimentary deposits, Late Permian lake and lake-bay sedimentary deposits and Mesozoic inland lake sedimentary deposits. The oil shale districts differ in area significantly; and the thickness of a single bed of oil shale generally ranges from 1 to 5 m and the total thickness also changes significantly in different oil shale districts. Oil shale is commonly brownish black and black with a slight greasy luster, and its oil content is 5-10%. Oil shale mostly occurs as beds. The oil shale formed in the Mid-Late Carboniferous and Jurassic commonly occurs in association with coal beds. The younger the oil shale is, the higher its REE abundance will be. All the identified oil shale deposits in northern China are located near large and medium-sized cities and have good prospects for exploitation and utilization. The Bag Maode area, Inner Mongolia, is very promising for oil shale.