GEOCHEMICAL BEHAVIOR OF SUBMARINE BITUMEN IN THE WEST OF THE NORTH YELLOW SEA BASIN

In order to forecast the hydrocarbon potential of the western part of North Yellow Sea basin (NYSB), sediment mineral identification,infrared spectrum, and organic gas chromatogram have been used to analyze the bitumen from 542 surface and column samples. The analytical results show that a large quantity of bitumens exist in the west part of NYSB, mainly distributed in the west fine-grained areas with a dominant strike of NNE and a minor NW. The OEP from different depth shows that the submarine sediments encountered a slight oil pollution. On the basis of the existing results of source rocks and pre-Mesozoic basement of NYSB, and according to the distribution of high content bituments, it is inferred that the bitumens could be from another source rock——lower Paleozoic limestone.