1. PetroChina Research Institute of Petroleum Exploration & Development, Beijing, China
2. SINOPEC Research Institute of Petroleum Engineering Co Ltd, Beijing, China
3. No.1 Oil Production Company of Daqing Oil Field Limited Company, PetroChina, Daqing, China
4. SSC JIANGHAN OILFIELD SERVICE COMPANY OF SINOPEC, Qianjiang, Hubei, China
5. COSL-EXPRO Testing Services (Tianjin) Co Ltd, Tianjin, China