1. School of Earth Science and Resources, Chang’an University, Xi’an, China
2. Exploration Department of Yan’ chang Oilfield Co. Ltd., Yan’an, China
3. Exploration Section of Wuqi Oil Production Plant, Yanchang Oilfield Co. Ltd., Yan’an, China
4. School of Geoscience and Technology, Southwest Petroleum University, Chengdu, Sichuan Province, China