1. College of Environment and Civil Engineering, Chengdu University of Technology, Chengdu 610059, China
2. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu 610059, China
3. China United Coalbed Methane Co. Ltd., Beijing 100011, China
4. Australian School of Petroleum and Energy Resources, University of Adelaide, Adelaide, 5005, Australia