SHALE GAS RESERVOIR-FORMING CONDITIONS AND EXPLORATION PROSPECT IN PERMIAN SHANXI FORMATION OF THE SOUTHERN NORTH CHINA BASIN

Dark shale is widely distributed in the Shanxi Formation of Permian in Southern North China Basin. Exploration prospects of shale gas in the region were studied in this paper based on the geologic background and the geochemical and drilling data. The Shanxi Formation ranges from 30 up to 100 m in thickness with an average of over 60 m in Taikang-Luyi area characterized by medium-high abundance of organic matter(1.76%-4.16%), and medium vitrinite reflectance. The organic matters are highly and over highly matured. Micro-cracks, and other types of pores are well developed for the formation of high quality reservoirs. The isothermal adsorption experiment shows that the dark shale has strong adsorption ability, which is 1.32 m³/t on average. It is concluded that the region of Xingyang-Tongxu-Taikang-Dancheng within the Southern North China Basin is favorable for shale gas exploration.