Re-evaluation of energy return on investment (EROI) for China's natural gas imports using an integrative approach

China's gas-import dependency has been growing rapidly, driven by increasing natural gas consumption paired with insufficient domestic reserves. Energy Return on Investment (EROI) has been widely applied to examine the net energy cost for natural gas production in China. EROI analysis for imported gas are, however, limited. The few existing studies on this topic have adopted inconsistent evaluation frameworks and have not considered life-cycle or environment-related energy inputs. This paper builds an integrative evaluation framework for natural gas imports in China and quantifies the EROI values for natural gas from seven major national exporters supplying to China. Results show a downward trend for the EROI of China's gas imports from 2009 to 2015 - more energy inputs were required for the same output - reflecting the increase in gas prices during this period. The average standard EROI of gas imports in 2015 is 10.2, slightly higher than that of domestic gas production at approximately 10. Consideration of life-cycle direct energy inputs and environment-related energy inputs results in a decrease in EROI by 18.2%-48.1%. Establishing an updated standard EROI evaluation framework for gas imports is the central contribution of this study. The updated EROI framework can provide a useful reference for research on gas imports for other countries.