Abstract: The depositional models of meandering river, braided river, anastomosed river and several delta have become the standard frames in comparing and interpreting the lothologic sequence in ancient rivers. But, it is very necessary that terminal fans is included in the depositional models by field and drilling data. The role, physiognomy, relevant deposits and sedimentology of terminal fans are different from delta regime. It is the deposition feature and sedimentary facies of the first zones of the upper section of member 2, Shahejie Formation in Pucheng Oilfield that are analyzed based on the abundant core data and the multidisciplinary analysis of well logging data and regional geology data. Result indicates the field is the terminal fan depositional system. On the base of researching in lithology, sedimentary facies sequence and sedimentary microfacies characteristics, the depositional model of terminal fans is established.

Key words: Dongpu Sag, Pucheng Oilfield, sedimentary microfacies, depositional model, terminal fan