1. Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process, Ministry of Education, China University of Mining and Technology, Xuzhou 221008, China
2. School of Resources and Geosciences, China University of Mining and Technology, Xuzhou 221116, China
3. School of Earth and Environment, Anhui University of Science and Technology, Huainan, Anhui 232001, China
4. Institute of Energy, Hefei Comprehensive National Science Center, Hefei 230000, China