Environmental impacts of shale gas development in China: a hybrid life cycle analysis

As the largest shale gas resources holder in the world, China has set ambitious goals for its shale gas development. To better understand the environmental impacts and the net energy return of shale gas development in China, this paper develops a hybrid life cycle inventory (LCI) model to estimate the energy use and greenhouse gas (GHG) emissions of China's shale gas development, and presents an energy return on investment (EROI) analysis for estimating its net energy return. Results suggest a total average energy use per well of 123 TJ (range: 74–165 TJ) and total average GHG emissions per well of 9505 tCOe (range: 5346–13551 tCOe). Most of the energy use and GHG emissions are indirect impacts embodied in fuels and materials. Energy use and GHG emissions from the drilling stage comprise the largest share in both totals due to large amounts of diesel used as fuel in the well drilling process and the materials used in the well casing process. The EROI of China's shale gas is estimated to be about 33 (range: 31–42), which is higher than China's conventional oil & gas but lower than U.S. shale gas