Reported Methane Emissions from Active Oil and Gas Wells in Pennsylvania, 2014–2018

Oil/gas
well integrity failures are a common but poorly constrained
source of methane emissions to the atmosphere. As of 2014, Pennsylvania
requires gas and oil well operators to report gas losses, both fugitive
and process, from all active and unplugged abandoned gas and oil wells.
We analyze 589,175 operator reports and find that lower-bound reported
annual methane emissions averaged 22.1 Gg (−16.9, +19.5) between
2014 and 2018 from 62,483 wells, an average of only 47% of the statewide
well inventory for those years. Extrapolating to the 2019 oil and
gas well inventory yields well average emissions of 55.6 Gg CH4. These emissions are not currently included in the state’s
oil and gas emission inventory. We also assess compliance in reporting
among operators and note anomalies in reporting and apparent workarounds
to reduce reported emissions. Suggestions for improving the accuracy
and reliability in reporting and reducing emissions are offered.