摘要
This paper makes a comparison between the Silurian Longmaxi Formation shale and the Mississippian Barnett Shale and in the Fort Worth Basin with similar tectonic and depositional settings.The result reveals the similarity and deformation differences between the Longmaxi Formation shale and the Barnett Shale.The research shows that the Longmaxi Formation shale and the Barnett Shale have the similar depositional setting,lithologic association and uplifting evolution model,but the Longmaxi Formation shale experienced polyphase deformations reconstruction and superimposition and formed different tectonic units with obvious differences in tectonic deformation,different fault-complex patterns and different types and scales of fractures.The tectonic deformation plays a very important role in the hydrocarbon accumulation and breakage of the Longmaxi Formation shale gas in the middle-upper Yangtze area of China.According to the residual thickness of the Longmaxi Formation shale and combined with the intensity of the tectonic deformation,the preferred potential zones of shale gas are suggested.They are the shale development area of South Sichuan and East Sichuan-West Hubei,but that of the South Sichuan is better.These areas with weakly deformation and far away from faults and absence of fractures may be the best targets for the shale gas exploration in both preferred exploration zones.