1. China Coal Research Institute, Beijing, China
2. China Coal Technology & Engineering Group Xian Institute, Xi’an, China
3. Oilfield Technology Service Company of Xinjiang Oilfield Company, PetroChina, Karamay, China
4. Karamay Hongshan Oilfield Co., Ltd of Xinjiang Oilfield Company, PetroChina, Karamay, China