1. School of Geosciences, China University of Petroleum (East China), Qingdao, Shandong, China 266580
2. Sanya Offshore Oil & Gas Research Institute, Northeast Petroleum University, Sanya, China 572025
3. Key Laboratory of Continental Shale Hydrocarbon Accumulation and Efficient Development, Ministry of Education, Northeast Petroleum University, Daqing, China 163318
4. Shale Gas Research Institute of PetroChina Southwest Oil & Gasfield Company, Chengdu, Sichuan, China, 610051
5. Exploration and Development Research Institute, Southwest Oil and Gas Field Company, Petrochina, Chengdu, China 610041