摘要
The sedimentary characteristics, distribution, evolution and favorable oil-bearing facies belts of near-shore subaqueous fan of Nantun Formation in Tanan Depression were studied. The results show that three kinds of sub-facies and four kinds of microfacies can be identified in near-shore subaqueous fan, and the different facies belts show obvious distinctions in sedimentary characteristics. The reservoir porosity of different places and burial depths shows a great discrepancy, therefore it is hard that the reservoirs formed a large joint area and high-quality ones. The study area mainly developed lithologic hydrocarbon reservoirs and structural-lithologic composite hydrocarbon reservoirs whose individual scale is small but quantities are numerous.