Perspectives of the Lower Palaeozoic shale gas resources in the middle-upper Yangtze area

The Lower Palaeozoic black shales in the middle-upper Yangtze area have proven to be important source rocks of the Sinian to the Permian large-to medium-sized gas fields,and also are of great potential in the accumulation of shale gas.The results of the preliminary study show that the favourable shale gas horizons are mainly developed in the Lower Sinian Doushantuo Formation,Lower Cambrian Qiongzhusi Formation,Upper Ordovician Wufeng Formation and Lower Silurian Longmaxi Formation.All these strata may be potential stratigraphic horizons for the future exploration of the shale gas due to favourable thickness of black shales,organic carbon contents and Ro values.