1. Research Institute of Natural Gas Technology, PetroChina Southwest Oil & Gasfield Company , Chengdu , 610213 , China
2. Mewbourne College of Earth & Energy, The University of Oklahoma , Norman , OK 73019-0390 , United States of America
3. PetroChina Southwest Oil & Gasfield Company , Chengdu , 610213 , China
4. Petroleum Engineering School, Southwest Petroleum University , Chengdu , 610500 , China
5. Southern Sichuan Gas Field, PetroChina Southwest Oil & Gasfield Company , Luzhou , 646000 , China