1. Oil and Gas Technology Research Institute of Changqing Oilfield Company , Xi’an , Shaanxi 710018 , China
2. National Engineering Laboratory for Exploration and Development of Low Permeability Oil and Gas Fields , Xi’an , Shaanxi 710018 , China
3. Changqing Oilfield Company, Oil Production Plant No. 5 , Dingbian , Ningxia 718699 , China
4. Petroleum Engineering College, Northeast Petroleum University , Daqing , Heilongjiang 163318 , China