1. School of Petroleum Engineering, Shandong Key Laboratory of Oilfield Chemistry, China University of Petroleum (East China), Qingdao 266580, P. R. China
2. School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao 266580, P. R. China
3. Research Institute of Petroleum Exploration & Development, PetroChina 100083, Beijing, P. R. China