SEDIMENTARY SYSTEM OF “FOUR FANS AND ONE CHANNEL” IN THE BOHAI GULF BASIN AND ITS SIGNIFICANCE FOR PETROLEUM EXPLORATION

This paper discusses the characteristics and distribution of sedimentary facies favorable for petroleum accumulation in Paleogene strata in the Bohai Gulf and its surroundings and their control on petroleum distribution.The sedimentary facies are obviously affected by structure.The understanding of the distribution of the sedimentary bodies is conducive to predicting petroleum distribution and can guide petroleum exploration.The classification of sedimentary systems should be based on a clear concept and various types of facies allow no overlapping.The sedimentary bodies in the Bohai Golf consist of fluvial fan facies,lacustrine delta facies,fan-delta facies,sublacustrine fan facies,non-fan channel turbidite facies,lakeshore-shallow lake beach-bar facies and semi-deep lake-deep lake facies(subfacies).The authors have studied the characteristics of various sedimentary systems and the characteristics of reservoirs of various systems in terms of source-reservoir-sealing.