1. School of Petroleum Engineering, China University of Petroleum (East China), Qingdao, Shandong, P. R. China;
2. Exploration & Development, Research Institute of Shengli Oilfield Co. Ltd, SINOPEC, Dongying, Shandong, P. R. China;
3. Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, P. R. China