SEDIMENTOLOGY AND HYDROCARBON POTENTIAL OF THE KUTEI BASIN,WESTERN INDONESIA

To better understand the filling history and petroleum geology of the Kutei basin,we studied in this paper the tectonic control over deposition,the distribution pattern of hydrocarbon source rocks and sedimentary evolutionary characteristics of the basin.Petroleum potential of the basin is discussed.The results show that 1)The basin experienced three stages of tectonic evolution,i.e.the rift stage(Eocene), depression stage(Oligocene-Early Miocene)and reversion stage(after Middle Miocene).By the end of Miocene, the basin suffered a transformational period from rapid deposition to erosion;2)Except the Eocene source rocks distributed locally,no Miocene source rocks have been found onshore,while Miocene deltacoal source rocks are widely developed offshore with strong capacity of hydrocarbon generation.The distribution patterns of the two sets of source rocks are different,leading to different discoveries onshore and offshore;3)There is high risk for exploration onland due to the limited capacity of hydrocarbon generation, and the risk in ultra deepwater area is even higher.As the conclusion,the favorable targets are located in the area where the Miocene source rocks occur within the zone upto 60km offshore,and the Miocene-Pliocene lithologic traps are the most potential targets for exploration.