High-Resolution Carbon Intensity of United States Natural Gas Supply

Understanding the greenhouse gas (GHG) emissions from natural gas systems is essential for transitioning to a low-carbon economy. This work estimates the well-through-transmission GHG emissions of the US natural gas from one million active wells covering 94% of 2022 US production. This is conducted by creating a high-resolution US oil and gas production area map to harmonize oil and natural gas supply chain data. We systematically integrate methane measurement data from the latest aerial campaigns into natural gas life cycle GHG emission estimates, capturing both methane fugitive (unintentional leakage and loss) and venting (intentional release) as well as a better characterization of super-emitter activities. Over ten public and commercial industry-leading datasets are integrated with an engineering-based unit process life cycle assessment (LCA) model. The estimated total GHG emissions are 631 MMT CO ₂ eq, more than twice that of the US Environmental Protection Agency estimates. The average well-through-transmission carbon intensity (CI) for US natural gas is 15.46 gCO ₂ eq/MJ, with an upstream (exploration through processing) CI of 12.35 gCO ₂ eq/MJ and a midstream (transmission) CI of 3.10 gCO ₂ eq/MJ. Methane fugitive and venting account for 73% and 16% of the upstream CIs, respectively, an order of magnitude higher than flaring emissions (1.6%). Reducing the methane fugitive and venting loss rates by 75% would lower the upstream CI by half.