1. College of Petroleum Engineering, Yangtze University, Wuhan 430100, China
2. Key Laboratory of Oil and Gas Resources and Exploration Technology, Ministry of Education, Wuhan 430100, China
3. Key Laboratory of Drilling and Production Engineering for Oil and Gas, Hubei province, Wuhan 430100, China
4. China United Coal-bed Methane Co., Ltd., Beijing 100020, China