1. Key Laboratory of Coalbed Methane Resource & Reservoir Formation Process, Ministry of Education, China University of Mining and Technology, Xuzhou 221008, China
2. School of Resources and Earth Science, China University of Mining and Technology, Xuzhou 221116, China
3. The Twelfth Oil Production Plant, Petro China Changqing Oilfield Company, Heshui 745400, China
4. College of Earth Sciences & Engineering, Shandong University of Science and Technology, Qingdao 266590, China