Abstract:
The Wufeng-Longmaxi formations in the Fuling shale gas play contain abundant shale gas resources, but the multiple tectonic superimposition had an important impact on shale gas preservation conditions in the area. We systematically studied the structural features and preservation conditions of shale gas in the Fuling area by detailed structural interpretation. There are two structural systems with NE and EW trends in the area, mainly formed in the late Yanshanian. Multi-level detachment structures were developed in the study area due to multi-phase tectonic movements. The detachment structures can be vertically divided into 3 different structural deformation layers. Structural style, fracture scale, erosion extent and fracture density were used as the main evaluation indicators for structural deformation, and the Fuling area was divided into the eastern and western belts. The structural deformation of the western belt was relatively weak, and the preservation conditions were relatively better. For further clarifying the favorable areas for shale gas development, a quantitative characterization method of preservation conditions was established by means of structural deformation characterization and reservoir prediction. According to evaluation results, three target units including Jiangdong, Pingqiao and Zilichang were selected in the western belt, and two target units including Baima and Baitao were selected in the eastern belt.