Controls of Buried History on Oil Accumulation Processes in Daqing Placanticline of Northern Songliao Basin

Based on data of more than 890 drilling wells, the controls of buried history on oil accumulation processes in the Daqing placanticline of northern Songliao basin have been elaborated by means of basin simulation and dating technique of oil reservoir. Northern Songliao basin had been undergone 3 subsidences and 2 uplifts. Duration of 3 subsidences are, respectively, Qingshankou-Nenjiang, Sifangtai-Mingshui and Tertiary-Quaternary periods, of them, during the periods, the biggest depositional rates with respectively 160 m/Ma and 180 m/Ma occur at Late Nenjiang and Mingshui periods. 2 uplifts respectively betided on the end of Nenjiang and Mingshui periods, which results in the formation of the Daqing placanticline. The oil generation and expulsion of the major source rocks of Qingshankou Formation maintain for a very long period, which started from about 77.4 Ma, and matched well with tectonic activity and formation of trap. The results indicate that two oil accumulation peaks occur respectively about 73 Ma and 65-40 Ma, which are in agreement with the processes of basin uplifts and structure formation.