The research of sedimentary system in the Hetaoyuan Formation of Paleogene in Biyang Depression

The sedimentary system in the Hetaoyuan Formation of Paleogene in Biyang Depression is researched by comprehensive methods of geology,log,seismic and core.The conclusion is that the Fan delta and lacustrine facies are two major depositional systems developed in the south actic region of Biyang Depression.According to the sedimentary environment and sediment features it can be divided into the fan delta plain,the fan delta front and the forefan delta subfacies,in which the fan delta front subfacies is the main part.The lacustrine deposit system can be divided into shallow lake,hemi-deep lake and deep lake subfacies.The main sediments mainly came from the south of Pingshi and Yangqiao.The sedimentary microfacies and sedimentary evolution are expounded.the depositional models and favorable hydrocarbon exploration zones are proposed