The sequence stratigraphic features and hydrocarbon accumulation of Songliao Basin
GUO Wei~(1), LIU Zhao-jun~(1), DONG Hui-min~(2), ZHAO Yu-jun~(2) (1.College of Earth Sciences, Jilin University, Changchun130061,China; 2.Bureau of Land and Resources of Heilongjiang Province, Harbin150091,China)
Based on outcrops,cores, well logs and seismic data, the identification mark and the stratigraphic sequence framework of different levels of sequence stratigraphy have been set up. Upper Cretaceous-Tertiary of Songliao Basin can be classified into Cretaceous rift basin megasequence and Tertiary rift basin megasequence. The Cretaceous rift basin megasequence can be classified into 3 supersequence sets, 7 supersequenes and 19 sequences. The tectonic evolution of Songliao Basin can be divided into three stages: fault basin, sag basin and withered basin. So the different mechanism of the fault basin and sag basin results in different sequence features and different filling series.According to the formations of source, reservoir and cover rocks and oil-gas gathering rule of each system tract in the sequence stratigraphic frame it can be concluded that RST developed the best reservoir sandbodies and enough oil-gas resource. On the other hand, LST, TST and HST were relatively poor on both aspects.