1. College of Petroleum Engineering, Xi’an Shiyou University, Xi’an, Shaanxi, P.R. China
2. Shaanxi Key Laboratory of Advanced Stimulation Technology for Oil & Gas Reservoirs, Xi’an, Shaanxi, P.R. China
3. Oil Production Technology Research Institute, Oil Production Plant NO.3 of Changqing Oilfield Company, CNPC, Yinchuan, Ningxia, P.R. China
4. School of Petroleum Engineering, Yangtze University, Wuhan, Hubei, P.R. China