Life cycle greenhouse gas emissions of China shale gas

Abstract

Having the largest shale gas reserve in the world, China is vigorously developing its shale gas resources. In this work, a hybrid life cycle inventory is used to estimate upstream greenhouse gas (GHG) emissions and evaluate the atmospheric environmental effects of China’s shale gas development. A comprehensive GHG emission model of the preproduction phase is constructed by considering green completion, methane emission from flowback water, indirect emissions from materials upstream material manufacturing, and Monte Carlo simulation. Results indicate that the upstream GHG emission of 230 shale gas wells is 18.8 g CO2eq/MJ. During the preproduction phase (from well pad preparation to well completion), indirect GHG emissions from upstream material manufacturing are substantial and account for 78%. The estimation of GHG emissions in preproduction phase presents considerable uncertainty (39%–79%) due to the uncertainty of constructing the pad preparation process and the estimated ultimate recovery. In preproduction phase, the GHG emission of China shale gas is estimated to be approximately 4.18 g CO2eq/MJ (95% CI: 2.57 to 7.47 g CO2eq/MJ), which is higher than that of the US shale gas.