1. Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process, Ministry of Education, China University of Mining and Technology, Xuzhou 221116, People’s Republic of China
2. Jiangsu Mineral Resources and Geological Design and Research Institute, China National Administration of Coal Geology, Xuzhou 221006, People’s Republic of China
3. School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou, Jiangsu 221116, People’s Republic of China