EPA says emissions from field production of natural gas accounted for 32.2 percent of
methane emissions from natural gas systems in 2012, but adds that those have come down more than 25 percent since 1990 — which is noteworthy when you factor in that natural gas production ramped up with the introduction of advanced fracking and horizontal drilling in the mid-2000s.
EPA's recent draft inventory of greenhouse gas emissions (1990 - 2015)
showed methane emissions from natural gas systems are down 18.6 percent since 1990, and emissions from petroleum systems are down 28.8 percent — without these recent regulations.
According to a 2011 report from EPA,
methane emissions from natural gas systems have declined since 2005.