Effective Permeabilities of Abandoned Oil and Gas Wells: Analysis of Data from Pennsylvania

Abandoned oil and gas (AOG) wells can provide pathways for subsurface fluid migration, which can lead to groundwater contamination and gas emissions to the atmosphere. Little is known about the millions of AOG wells in the U.S. and abroad. Recently, we acquired data on methane emissions from 42 plugged and unplugged AOG wells in five different counties across western Pennsylvania. We used historical documents to estimate well depths and used these depths with the emissions data to estimate the wells’ effective permeabilities, which capture the combined effects of all leakage pathways within and around the wellbores. We find effective permeabilities to range from 10^–6 to 10² millidarcies, which are within the range of previous estimates. The effective permeability data presented here provide perspective on older AOG wells and are valuable when considering the leakage potential of AOG wells in a wide range of applications, including geologic storage of carbon dioxide, natural gas storage, and oil and gas development

Geospatial analysis of near-term potential for carbon-negative bioenergy in the United States

Bioenergy with carbon capture and storage (BECCS) is widely utilized in ambitious climate mitigation scenarios as a negative-emissions technology. However, the future technical potential of BECCS remains uncertain. Two significant deployment barriers that have largely been overlooked by previous studies are the suitability of existing storage sites and the availability of transportation of biomass and/or CO 2 . This study assesses the near-term deployment potential of BECCS in the United States in the absence of long-distance transportation networks. Considering these constraints, 30% of the projected available 2020 biomass resources can be utilized for BECCS, yielding a negative-emissions potential of 100 Mt CO 2 ⋅y −1 . The analysis further pinpoints areas with colocated resources that could be prioritized for near-term deployment of BECCS. Bioenergy with carbon capture and storage (BECCS) is a negative-emissions technology that may play a crucial role in climate change mitigation. BECCS relies on the capture and sequestration of carbon dioxide (CO 2 ) following bioenergy production to remove and reliably sequester atmospheric CO 2 . Previous BECCS deployment assessments have largely overlooked the potential lack of spatial colocation of suitable storage basins and biomass availability, in the absence of long-distance biomass and CO 2 transport. These conditions could constrain the near-term technical deployment potential of BECCS due to social and economic barriers that exist for biomass and CO 2 transport. This study leverages biomass production data and site-specific injection and storage capacity estimates at high spatial resolution to assess the near-term deployment opportunities for BECCS in the United States. If the total biomass resource available in the United States was mobilized for BECCS, an estimated 370 Mt CO 2 ⋅y −1 of negative emissions could be supplied in 2020. However, the absence of long-distance biomass and CO 2 transport, as well as limitations imposed by unsuitable regional storage and injection capacities, collectively decrease the technical potential of negative emissions to 100 Mt CO 2 ⋅y −1 . Meeting this technical potential may require large-scale deployment of BECCS technology in more than 1,000 counties, as well as widespread deployment of dedicated energy crops. Specifically, the Illinois basin, Gulf region, and western North Dakota have the greatest potential for near-term BECCS deployment. High-resolution spatial assessment as conducted in this study can inform near-term opportunities that minimize social and economic barriers to BECCS deployment