1. Department of Petroleum Engineering and Shale Gas Industry Development Institute of Sichuan Province, Petroleum Engineering School, Southwest Petroleum University, Chengdu, Sichuan 610500, China
2. Department of Petroleum Engineering, Petroleum Engineering School, Southwest Petroleum University, Chengdu, Sichuan 610500, China
3. Department of Well Completion and Fracturing, Shale Gas Research Institute, CNPC Southwest Oilfield, Chengdu, Sichuan 610500, China
4. Department of Petroleum Engineering, College of Engineering and Applied Science, University of Wyoming, 1000 East University Avenue, Laramie, WY 82071-2000
5. Department of Unconventional Gas Research, PetroChina Research Institute of Petroleum Exploration & Development, Beijing 10083, China