**Acknowledgements**

This study was supported by EGI's multiyear China Shale Plays consortium (100980) and Open fund from Sinopec Key Laboratory of Shale Oil/Gas Exploration and Production Technology (Grant no. G5800-15-ZS-2X038), Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education (China University of Geosciences) (TPR-2017-02), Key laboratory of strategy evaluation for Shale gas of Ministry of Land and Resources, U.S. National Science Foundation (No. 1661733) and China National Natural Science Foundation (nos. 41728004, 41302089 and 41472112). We are also grateful to reviewers and handling editor for their critical comments and constructive suggestions. The international collaboration between PetroChina, Sinopec, CNOOC, China University of Geosciences at Beijing, China University of Geosciences at Wuhan, China Geological Survey, China University of Petroleum at Beijing, China University of Petroleum at Qingdao and EGI also made this research and book chapter possible.
