Petroleum geology of the Huanghua Basin, eastern China

The Huanghua Basin is a Tertiary graben within the Bohai Basin Complex situated approximately 160 km southeast of Beijing, People's Republic of China. The Bohai Basin is bounded on the south by the Luxi Uplift, on the north by the Yanshan Fold Belt and on the west by the Taihangshan Uplift. The Huanghua Basin, within the Bohai Basin, is elongated in a NE-SW direction and is bounded on the west by the Tsangxian Uplift and on the southeast by the Chengning Uplift. Basement rocks of the Huanghua Basin are Archaean and Lower and Middle Proterozoic. The Upper Proterozoic to the Pliocene is up to 15 000 m thick - 6000 to 8000 m being Tertiary continental clastics with some volcanics, anhydrite and Limestone coquinoidal beds. The main source rocks for petroleum are in the Lower Tertiary. Traps for that oil are located in the Ordovician, Carboniferous, Permian, Mesozoic and Tertiary sediments. Source beds in the Huanghua Basin contain total organic carbon of 1.5-5.0%, chloroform soluble bitumen of 0.15-0.30%, total hydrocarbon content of 1500 to 2500 ppm, hydrocarbon yield of 20 x 10(6) tonne/km(3) and potential hydrocarbon production of 10 to 30 kilograms/tonne of rock. Migration of hydrocarbons is along unconformities and along faults. The oil ranges from immature heavy oil to overmature condensate. Approximately 50 x 10(6) tonne (approximately 59 x 10(6) m(3), or 370 million barrels) of oil were produced during 1965 to 1985. This is a large amount of oil produced from a basin having 18 629 km(2) and it provides encouragement for future exploration.