1. Natural Gas Research Institute, PetroChina Southwest Oil and Gas Field Company 1 , Chengdu, Sichuan 610213, China
2. Key Laboratory of Natural Gas Quality Control and Energy Measurement for State Market Regulation 2 , Chengdu, Sichuan 610213, China
3. Gas Transmission Department, PetroChina Southwest Oil and Gas Field Company 3 , Chengdu, Sichuan 610213, China