A new study released today shows that methane emissions from wells completed via the hydraulic fracturing process are actually 50% less than estimates made by the U.S. Environmental Protection Agency. The study, released by URS Corp. and The LEVON Group, uses data from nearly 20% of all natural gas producing wells in the United States (more than 91,000 wells, to be more specific), a data set that is more than ten times larger than what EPA used. The study was commissioned by America's Natural Gas Alliance (ANGA) and the American Petroleum Institute (API).
More specifically, the study found that methane emissions from a technique known as "liquids unloading"—used to remove water and other liquids to improve the flow of natural gas in the wellbore—are 86% lower than what EPA estimated, while methane emissions from refractured wells are 72% lower. EPA's inflated data on liquids unloading is particularly significant, as that phase accounted for more than half of all the emissions from natural gas systems for which the EPA accounted in its estimates.
The researchers concluded that, had EPA relied on this larger and more complete data set, its emissions estimates would be 50% lower.
Of course, this isn't the first study to raise doubts about EPA's methane numbers.
A report from IHS-CERA, for example, found that EPA's estimates for methane emissions are "dramatically overstated" and "not credible," adding that it would be "unwise to use them as a basis for policymaking."
Furthermore, a study earlier this year from the Environmental Defense Fund highlighted the fact that EPA's current estimate of methane emissions is "double the prior estimate, which was itself twice as high as the previously accepted amount."
Those findings are particularly significant considering that the EPA has admitted its estimates are based "mostly" on two studies "conducted in the early and late 1990s." In other words, EPA increased its estimates not by gathering new data, but rather largely through changes in inputs to computer models.
The takeaway from all of this is not just that EPA's data is flawed or that the agency needs a better system for creating its emissions inventory—although both of those are salient points. The bigger story is really that these substantially lower emissions estimates demonstrate just how committed the industry is to reducing environmental impacts, even without burdensome and duplicative new regulations. As the new study notes:
"It is clear that companies are not waiting for regulatory mandates or incentives to upgrade equipment, or to alter practices like venting and flaring in favor of capturing methane where practical. Instead, operators are seizing opportunities to reduce the potential environmental impacts of their operations. Industry is therefore confident that additional, systematic collection of production sector activity data will not only help target areas for future reductions but also demonstrate significant voluntary progress toward continually 'greener' operations." (ANGA/API study, p. v)
Be sure also to check out ANGA's release, which further summarizes and contextualizes the study's findings.
Steve Everly
Energy InDepth
