Analysis of characteristics of upper hydrocarbon play of Mesozoic-Paleozoic marine group, Lower Yangtze region

With multiple stages of tectonic evolution in the Lower Yangzte region, the upper hydrocarbon play (mainly in the upper Pa-leozoic and Mesozoic) has been strongly superimposed. The source rock, reservoir, cap are adjusted and reconstructed, which results in the complex conditions of petroleum accumulation. Based on the analysis of the process of petroleum accumulation and time-space matching relation, this paper indicates that the source rock, reservoir rock and cap rock of the upper hydrocarbon play have an excel-lent combination. Essentially, the play has not been destroyed and reformed strongly by the later tectonic movements. And the reservoir forming factors are valid in time and space. It is the most prospective play in the Lower Yangzte region. Meanwhile, the hydrocarbon play is the essential condition of late entrapment. Yanjiang area, located in south-north hedge frontal belt, is the weak deformation zone of marine strata in which the strata is relatively complete and the reservoir forming factors have been deposited well. The hydrocarbon reservoirs of Paleozoic source-Cenozoic reservoir and Paleozoic source-Paleozoic reservoir are found in this area which is the most fa-vorable exploration areas in Lower Yangzte region.