1. College of Petroleum Engineering, China University of Petroleum (East China), Qingdao 266580, PR China
2. Key Laboratory of Unconventional Oil & Gas Development (China University of Petroleum (East China)), Ministry of Education, Qingdao 266580, PR China
3. College of Petroleum Engineering, China University of Petroleum (Beijing), Beijing 102249, PR China
4. No.2 Oil Production Plant of Changqing Oilfield Company, Qingyang 745000, PR China