Research Institute of Petroleum Exploration and Development PetroChina Beijing 100083 China;
Shandong Provincial Key Laboratory of Depositional Mineralization & Sedimentary Mineral Shandong University of Science and Technology Qingdao 266590 China;
Changqing Oilfield Research Institute of Petroleum Exploration and Development CNPC Xi’an 710018 China;
shale formation; oil and gas resources; orderly accumulation and coexistence; integrated exploration and development;