Environmental impacts from conventional and shale gas and oil development in China considering regional differences and well depth

Abstract

China has stepped up its oil and gas development including unconventional resources as foreign dependence for oil and gas increased. Environmental impacts from the development phase has also caused widespread concern. To better understand environment impacts from current oil and gas development in China, a hybrid life cycle analysis (H-LCA) model was used to estimate the impact of six fields at the development stage based on data from 2017. The full environmental impact and full impact intensity (i.e., full environmental impact per unit of output by calorific value) of shale gas, conventional natural gas and oil development in China was compared and analyzed by eliminating well depth. Shale gas has 12.5% more environmental impact than conventional natural gas. Environmental impact of natural gas development is roughly 1.5 to 2 times that of conventional oil. Development of gas in Sichuan Basin have the greatest environmental impact, following southeast coast, Song Liao Basin, and Junggar Basin. However, the full impact intensity of shale gas development is more than five times that of conventional natural gas, but natural gas is still greener than conventional oil. The greatest full impact intensity is found in Junggar Basin, following Song Liao Basin and southeastern coast. From the comparison of full environmental impact and full impact intensity under per well depth, it's found that both of these are not positively correlated with reservoir depth and well depth even in the same basin. More attention should be paid to driving effects of specific reservoir developments and geological conditions.