Shale gas exploration prospect of Lower Paleozoic in southeastern Sichuan and western Hubei-eastern Chongqing areas, China

Lower Cambrian Niutitang Formation and Upper Ordovician Wufeng Formation-Lower Silurain Longmaxi Formation are two sets of transgressive shale, featured by rich in pyrite, organic and fossils in black shale. The thickness of the two shales is large and distribution is widespread. The organic evolution of Niutitang Formation is high and buried depth is deeper than that of Longmaxi Formation. It is clear that no gas shows in Lower Cambrian shale but abundant gas shows in Lower Silurian, particularly, industrial gas is found in some siltstones. Based on the above study, Lower Silurian is more favorable to research and develop of shale gas exploration, and is more suitable to look as target stratum for shale gas exploration in southeastern China strategic objectives pilot area. In a word, the exposed area of two sets of shale in the study area is very wide, and is very helpful to start against shale research, especially in the anticline and syncline wings.