1. School of Energy Resource, China University of Geosciences, Beijing 100083, China
2. Coal Reservoir Laboratory of National Engineering Research Center of CBM Development & Utilization, China University of Geosciences, Beijing 100083, China
3. Sichuan Energy Mining Investment and Development Co., Ltd., Chengdu, Sichuan 610081, China
4. Sichuan Shale Gas Exploration and Development Co., Ltd., Neijiang, Sichuan 641000, China