Thermal Evolution Of Jurassic Source Rocks In Western North Margin Of Qaidam Basin

The Jurassic contains the most important source rocks in western north margin of Qaidam Basin.The complex hydrocarbon generation history is systematically studied.On the basis of drilling data,seismic data and testing data,the thermal evolution history of Jurassic source rock is simulated by the model of EASY%Ro in different structural units.The research shows that the thermal evolution degree of Jurassic source rocks decreased gradually from west to east.The Lower Jurassic source rocks in the Kunteyi and Yibei Sags entered the hydrocarbon generation threshold in the Early Paleogene and reached the peak in the Late Paleogene.The Middle Jurassic source rocks in the Saishiteng Sag entered the hydrocarbon generation threshold in the Late Pliocene and has been still staged at the oil generation peak.The center of northern margin of the Qaidam Basin underwent two key accumulation periods in the Late Yanshanian and Late Himalayan respectively.According to the matching relationship in stages between the hydrocarbon generation and expulsion and the tectonic reformation,it is clear that the seventh structure in the Lenghu belt is the favorable zone for further exploration.