Distribution of residual Mesozoic basins and their exploration potential in the western depression zone of East China Sea Shelf Basin

The East China Sea Shelf Basin is the largest Meso-Cenozoic sedimentary basin in the area offshore China formed by the subduction of the paleo-Pacific Plate in late Mesozoic. Current oil and gas discoveries are mainly from the Cenozoic deposits, and the distribution patterns and resource potentials of the Mesozoic remain unclear. Previous studies show that, the Mesozoic strata in the western depression zone of the East China Sea Shelf Basin have uplifted and been denuded to some extent in later stage suggesting the distribution pattern of a residual basin, and the eastern depression zone remain unclear due to lack of drilling evidence and the low quality of the seismic data from the medium and deep parts. Based on the well-seismic calibration for the western depression zone and the classification and identification of the Mesozoic seismic facies in the regional seismic profiles, this paper divided the stratigraphic sequences of the Jurassic and Cretaceous, summarized the structure and plane distribution patterns of the residual Mesozoic basins, and analyzed the basic factors which control the petroleum accumulation. The result suggests that the exploration potential of the Mesozoic in the East China Sea Shelf Basin should not to be ignored.