Study On The Sequence Stratigraphy And The Petroleum System Baoqian Area In Songliao Basin

he explorable simple structural oil pools and the high porosity and permeability reservoirs, like many other oilfields in China, have gradually reduced in Jilin oilfield since 1990s, so the main exploration targets have been changed to subtle and complex reservoirs. For extending the exploration areas, the Cretaceous in Baoqian area in central depression of south Songliao basin is studied in this project, with the purpose of looking for the lithologic reservoirs.The sequence stratigraphy and the hydrocarbon-bearing system theory, which are two advanced subjects in geology, are combined for the first time in this project. The results of this research can be applied to practical productive studies, which can integrate theory with practice and transform the scientific technology into productivity. The prospects of various reservoirs are determined by studing the stratigraphic sequences and depositional systems, establishing the stratigraphic time-space frameworks of the basin, analyzing the depositional features of different depositional backgrounds, describing the 3D geometries of the sand bodies, reconstructing the palaeogeographic framework and determining the characteristics of the source-reservoir-seal assemblage for each set of sedimentary series in Baoqian sand bodies in south Songliao basin.The hydrocarbon-bearing system is studied and the assessment of the resource and exploration potentials are made by describing the static characteristic of the system, analyzing the dynamic characteristic of the system, studing the hydrocarbon generation potential and the course of hydrocarbon migration and accumulation, analyzing the source-reservoir-seal match and packing times and courses as well as predicting the potential exploration areas.Based on the study of the reservoir-forming conditions such as the mechanism of the hydrocarbon generation, the times of the hydrocarbon migration and accumulation, the negative structural reservoir model and the time-space evolution of the delta front facies, a geologic model suitable for oil and gas exploration in synclinal area of large lake basin is suggested, that is, there is exploration potention in the negative structural lithologic reservoirs.