1. School of Petroleum Engineering and Environmental Engineering, Yan’an University, Yan’an 716000, China
2. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China
3. Development Department, Shaanxi Yanchang Petroleum Group Co., Ltd., Yan’an 716000, China
4. Fifth Oil Production Plant, PetroChina Changqing Oilfield Co., Xi’an 710200, China