1. Key Laboratory of Deep Oil and Gas, School of Geosciences, China University of Petroleum (East China), Qingdao, Shandong 266580, China
2. China United Coalbed Methane Corporation Ltd., Beijing 100083, China
3. Sanya Offshore Oil and Gas Research Institute, Northeast Petroleum University, Sanya 572025, China
4. Key Laboratory of Continental Shale Hydrocarbon Accumulation and Efficient Development, Ministry of Education, Northeast Petroleum University, Daqing 163318, China