Certain types of Pennsylvania’s scores of abandoned oil and gas wells are associated with higher emissions of the greenhouse gas methane, according to a study published Monday that could help government agencies prioritize efforts to plug the biggest leaks.
The study of 88 wells across Western Pennsylvania led by Mary Kang, a postdoctoral fellow at Stanford University, revealed that high-emitting wells tend to be natural gas wells that are either unplugged or that are plugged but vented in coal-rich areas.
Abandoned oil wells had consistently lower emissions than the abandoned gas wells in the study. Proximity to active natural gas storage fields or new shale gas wells appeared unrelated to methane flow rates from abandoned wells, according to the report in the Proceedings of the National Academy of Sciences.
The highest emitters are a particularly valuable target in efforts to curb releases of the powerful greenhouse gas, which has 86 times the heat-trapping potential of carbon dioxide in the atmosphere over a 20-year period.