1. Cooperative Innovation Center of Unconventional Oil and Gas (Ministry of Education & Hubei Province), Yangtze University, Wuhan, China and Key Laboratory of Exploration Technology for Oil and Gas Resources of Ministry of Education, Wuhan, China. (corresponding author)
2. Zhejiang University, School of Earth Sciences, Hangzhou, China.
3. The University of Texas at Austin, Jackson School of Geosciences, Bureau of Economic Geology, Austin, Texas, USA.