In several recent studies on methane emissions relating to the natural gas industry, scientists concluded that the U.S. Environmental Protection Agency (EPA) underestimated the quantity of methane the industry releases to the atmosphere. A study released Monday, based on air samples above wells in the Marcellus Shale formation in Pennsylvania, indicates that methane emissions may be from 100 to 1000 times higher than EPA estimates. But this study also found that hydraulic fracturing was not a primary source of methane emissions. Rather, the study identified the major discrepancy in methane emissions estimates with drilling process leaks that occur before natural gas production techniques, such as fracking, are used on the well. The drilling process has not previously been considered a significant source of methane emissions.
Also this week, EPA released five white papers for peer review identifying fracking, along with compressors, leaks, liquids unloading and pneumatic devices, as a potentially significant source of methane and volatile organic compound (VOC) emissions. The papers are the first step in President Obama’s Climate Action Plan Strategy to Reduce Methane Emissions targeting several areas, including the oil and gas sector, for reducing methane emissions. The plan directs EPA to assess potentially significant sources of emissions and develop additional regulations to address those sources by the end of 2016.
In the fracking white paper, EPA examines several emission mitigation techniques to control methane emissions associated with fracking. These include reduced emission completions (RECs), completion combustion devices, natural gas liquids (NGL) recovery and natural gas reinjection. EPA found that combustion is currently the most common method for controlling fracking emissions but that RECs, aka green completions, are also used. EPA also notes that the availability of NGL recovery and gas reinjection technology may limit the use of these other methods of control. It is likely that in developing additional regulations, as directed under the President’s plan, EPA will focus on existing technologies. As a preview, EPA already promulgated regulations that will require RECs to reduce VOC emissions associated with fracking under the New Source Performance Standards beginning in 2015 (see August 23, 2012, blog post).