Constraining Methane Leakage from Abandoned Oil and Gas Wells

While abandoned, Orphaned, and/or Lost (AOL) oil and gas wells provide a potential pathway for migration and emissions to the atmosphere of methane and other volatile hydrocarbons, little is known about fluxes from the millions of AOL wells that exist in the coterminous USA. The objective this project is to collect sufficient data to permit a robust scaling up of findings to produce a regional estimate of methane leakage from AOL wells in Pennsylvania and Colorado so that these emissions may be included in a greenhouse gas emission inventory. Instantaneous measurements of methane will be carried out and collected and analyzed (both gas chromatographic and isotopic analyses) in order to characterize the thermogenic methane source separately from any biogenic contributions. A framework in which new measurements can be included to improve formation-, state- and US-scale methane emission estimates from AOL wells in methane emission inventories will be created to provide a baseline of leakage from AOL wells so that a later determination of whether new extraction increases leakage rates from AOL wells can be made.