Legacy wells supporting net zero by screening carbon storage and geothermal potential in the United States

Depleted oil and gas reservoirs provide an opportunity to repurpose underperforming wells and reuse existing subsurface infrastructure to support Net Zero transitions. Here we present a United States wide screening analysis of underperforming wells to estimate upper bound technical potential for carbon storage and geothermal heat. Using public well inventories, county level carbon removal cost datasets, national scale storage resource maps, and geothermal resource data, and accounting for well integrity attrition and field scale constraints, we estimate carbon storage potential of approximately 0.024–1.17 gigatonnes per year and geothermal heat potential of approximately 1–35 gigawatts thermal across high potential regions. Avoided drilling and deferred abandonment may indicate upper bound cost benefits, although repurposing costs remain site-specific. Key constraints include well integrity and cooling during injection; a retrofittable downhole choke is evaluated to mitigate this during startup. These results highlight conditional potential and the need for site-specific assessment.