Discovery and geological significance of high-quality source rock in Bei'er sag of Hailaer Basin,China

The Bei'er sag is one of the most rich oil sags in the south of Hailaer Basin in China.The author of the paper focuses on the research of the source rock feature of the Bei'er sag,and finds that there are high-quality source rock in Member 1 of Lower Cretaceous Nantun Formation of the sag.This source rock is the alternating beds of the dark peat,muddy limestone,oil shale and calcium shale,and the source rock has the high abundance of organic matter,good organic matter type,high hydrocarbon-generating potential and high hydrocarbon-exhausting efficiency.All of these are the material base to form the large scale oil and gas accumulation.The formation represents the anoxic event early in Cretaceous period and is the significant stratigraphic correlation marker bed of the Bei'er sag.In Member 1 of Nantun Formation,the high-quality source rock controls the plane distribution of the oil and gas.Above and below the high-quality source rock bed,the oil and gas are very rich.