1. Research Institute of Natural Gas Technology, PetroChina Southwest Oil & Gasfield Company, Chengdu 610213, China
2. Engineering Technology Department, PetroChina Southwest Oil & Gasfield Company, Chengdu 610056, China
3. Development Department, PetroChina Southwest Oil & Gasfield Company, Chengdu 610056, China
4. Northwest Branch, Research Institute of PetroChina Exploration & Development, Lanzhou 730020, China