1. State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China
2. State and Local Joint Engineering Laboratory of Methane Drainage in Complex Coal Gas Seam, Chongqing University, Chongqing 400044, China
3. Department of Earth Sciences, Uppsala University, Villavägen 16, SE-75236 Uppsala, Sweden
4. Key Laboratory of Shale Gas Exploration, Ministry of Natural Resources, Chongqing Institute of Geology and Mineral Resources, Chongqing 401120, China
5. Research Institute of Yanchang Petroleum (Group) Co. Ltd., Xian, Shaanxi 710075, China