1. China United Coalbed Methane Corporation, Ltd., Beijing 100011, China
2. Downhole Technology Operation Company, CNPC Chuanqing Drilling Engineering Company Limited, Xi’an 710021, Shanxi, China
3. Exploration and Development Department, China ZhenHua Oil Co., Ltd., Xicheng District, Beijing 100031, China
4. Petroleum Engineering College, Yangtze University, Wuhan 430100, China
5. State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102249, China
6. Petroleum Engineering Department, Colorado School of Mines, Golden, Colorado 80401, United States