1. School of Earth Sciences and Key Laboratory of Mineral Resources in Western China (Gansu Province); Lanzhou University; Lanzhou 730000 Gansu China
2. Petro China Changqing Oil Field Company; Xi'an 710018 Shaanxi China
3. National Engineering Laboratory for Exploration and Development of Low-Permeability Oil & Gas Fields, CNPC, Xi'an; 710018 Shaanxi China
4. Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics; Chinese Academy of Sciences; Lanzhou 730000 Gansu China
5. China University of Petroleum; Beijing 102249 China