Abstract: The shale in sea-land transitional facies of Permian Leping Formation is developed in the Lower Yangtze region. Based on the investigation of structure and sedimentary background in this area through some experiment measures, we analyzed the organic geochemical characteristics, rock and mineral characteristics, physical conditions and storage space types of cores, and then discussed the main sedimentary and structural factors affecting gas content of shale. The research results show that the shale thickness of Permian Leping Formation in Fengcheng-Leping area is very different and heterogeneous; The Wangpanli and Lower Laoshan Subsections are good hydrocarbon source rocks, and the Upper and Middle Laoshan Subsections are medium hydrocarbon source rocks; the main organic matter type of shales is Ⅱ₂, which is the main gas source in the west area, the maturity of organic matter is characterized by "low in the east and high in the west"; the micro-pores and micro-cracks are the main pore spaces; the whole physical property is ultra-low porosity and low permeability. The Permian sea-land transitional environment in the study area provided the basis for the development of hydrocarbon source rocks; the moderate burial depth guarantees the high content of shale gas and low production cost; the complicated structure and intense deformation in the eastern area is not conducive to the preservation of shale gas; the structure of western area is stable, and has a good prospect for gas exploration.

Key words: shale gas, Pingle depression, Leping Formation, geochemical parameters, geological conditions