Abstract:

The Sanghe sub-sag in Baiyinchagan sag develops three sets of source rocks, i.e. the first Member of Duhongmu Formation, Tenggeer Formation and the second Member of Aershan Formation, with long hydrocarbon generation time, multiple-accumulation periods and well-developed faults. It is favorable for the formation of the commingle crude oil in the geological and geochemical conditions. The three sets of source rocks are the important oil sources in Sanghe region. The analytical data of biomarkers and carbon isotope from crude oil show that crude oil in the region can be divided into three types, primary low mature crude oil, primary mature crude oil, and blend crude oil. The first two types of which come from lower Member of Tenggeer Formation and the second Member of Aershan Formation, they are the hydrocarbon products in different periods of source rocks. The third type of crude oil, typical binary blend crude oil, comes from the mixing process of the first two types.

Key words: Baiyinchagan sag, Sanghe region, blend crude oil, oil-source correlation；petroleum gas