Exploration prospect of gas-bearing marine mudstone-shale in Lower Palaeozoic in the central Yangtze area, China

Based on the data of geochemistry, gas show of drilling and outcrop of the Lower Paleozoic shale, this paper analyzed exploration prospects of Lower Paleozoic shale gas in the central Yangtze area. The analysis indicate that the Lower Paleozoic marine shale included Lower Cambrian Shuijingtuo Formation (or Niutitang Formation), Upper Ordovician Wufeng Formation and Lower Silurian Longmaxi Formation in the central Yangtze area, which have rich organic matter content, fine kerogen type, high thermal evolution(mature to over mature), were valid source rocks of shale gas. The central Yangtze area has experienced multiphase tectonic movements since Caledonian. The shale reservoirs property was improved by tectonic uplift and compression, and accumulation for shale gas was improved. Lower Cambrian shales and/or mudstones are prospect for shale gas exploration in western Hunan and Hubei and southern Jianghan plain. While the commercial gas flow in Silurian shales and/or mudstones was revealed by drilling, which indicated that the potential of exploration for shale gas is great in western Hubei and eastern Chongqing.