Sequence Stratigraphic Study of Paleogene and Neogene Salt Lake,Southwestern Qaidam Basin

Sequence stratigraphic study of the salt lake with lately started and weak foundations in Qaidam Basin is important in many respects. In order to analyze the sequence stratigraphy in Paleogene and Neogene in southwestern Qaidam Basin and provide a foundation for lithologic hydrocarbon reservoir exploration,this paper studies the sequence boundary identification and the sequence classification in Paleogene and Neogene in southwestern Qaidam Basin by using sequence stratigraphic method,and applying outcrop data,core,drilling data and seismic data. It is shown that the classification in terms of 13 long-term circles is reasonable,and there are 4 sequence developing patterns:gentle slope zone,abrupt slope zone,low uplift zone and Lake Basin. And it is also shown that the sequence circle structure plays a significant role in controlling the lithologic trap,the development of sandstone reservoir is closely related to the mid-term circle,and favorable reservoirs mainly develop at the bottom of the circle structure with a trend of becoming deeper upward.