1. School of Petroleum Engineering, China University of Petroleum (East China), Qingdao, Shandong 266580, China
2. Key Laboratory of Unconventional Oil and Gas Development (China University of Petroleum (East China)), Ministry of Education, Qingdao, Shandong 266580, China
3. Oilfield Production Department, China Oilfield Services Limited, Tianjin 300451, China