Abstract:
National shale gas resource assessments indicate that the Permian strata of Wuwei Basin in the Lower Yangtze region has favorable shale gas potential. However, the basin remains underexplored, and the available geological and geophysical data are insufficient to support robust area selection and exploration deployment. Based on the newly acquired 2D seismic data, the study carried out prestack seismic processing, horizon and fault interpretation, and time-depth conversion, and delineated the structural framework, fault characteristics, and stratigraphic distribution of the basin, and the distribution, structural configuration, burial depth, and thickness of the Permian shale gas target interval. The results showed that NE-trending faults controled the basin architecture and the spatial distribution of sedimentary systems, producing a pattern of vertical stratification and lateral zonation. The Indosinian unconformity separates a lower structural unit dominated by reverse faults from an upper structural unit dominated by normal faults. In plan view, the Paleozoic-Mesozoic succession exhibited a NE-trending belt-like configuration of two sags flanking an uplift. By integrating shale gas geological conditions, target-interval thickness, burial depth, and structural preservation conditions, favorable prospect areas were delineated and three preliminary drilling target areas were selected along the 2D seismic profiles. These results could provide geophysical basis for further shale gas exploration in Wuwei Basin and support oil and gas geological survey in the Lower Yangtze region.