Well pad-level geospatial differences in the carbon footprint and direct land use change impacts of natural gas extraction†

Thorough accounting of the climate change impacts of natural gas is crucial to guide the energy transition towards climate change mitigation, as even decarbonization roadmaps project continued natural gas use into the future. The climate change impacts of natural gas extraction have not previously been assessed at the well pad level, accounting for a multitude of geospatial differences between individual pads. Well pads constructed across a varied landscape lead to a range of well pad areas, earth flattening needs, well pad lifetimes, total gas production, and direct land use change (DLUC) effects such as loss of original biomass, soil organic carbon loss, change in net primary productivity, and altering the surface albedo of the site. Using existing well pad data, machine learning techniques, and satellite imagery, the spatial extents of thousands of well pads in New Mexico were delineated for site-specific data collection. A parametric life cycle assessment (LCA) model of natural gas-producing well pads was developed to integrate geospatial differences and DLUC effects, yielding scenario analysis results for each identified well pad. The DLUC effects contributed a median of 14.4% and a maximum of 59.0% to natural gas extraction carbon footprints. The use of well pad-level data revealed that the carbon footprint of natural gas extraction ranges across orders of magnitude, from 0.016 to 46.4 g CO₂eq per MJ. The results highlight the need to quantify the climate change impacts of establishing a well pad and extracting natural gas case-by-case, with geographically specific data, to guide new installations towards lower emissions.