One of the big takeaway from the big UT Austin/Environmental Defense Fund (EDF) methane leakage study released today is emissions rates are actually lower in some parts of the production process than initially thought.
For wellheads surveyed as part of the study, two-thirds of the wells had new emissions capture control technology installed, so-called “green completion” tech. On these wells 99% of potential emissions were captured orcontrolled.
This study provides scientific data about how more stringent regulations from the US EPA will reduce methane leakage:
According to [EDF Chief Scientist Steve] Hamburg, UT's low well emissions finding indicates an early phase-in of EPA's New Source Performance Standards (NSPS), which requires all new fractured natural gas wells to either burn-off or use "green completions" (an emissions control method that routes excess gas to sales), is working. Results also suggest that these new regulations, which will be fully implemented in 2015, are having the desired effects. No national survey of how many operators currently use green completions is available, but the data suggest that once this practice is required, emissions from this phase of the production process will decline.
This is encouraging news. It is also a small sample size of well sites from nine energy companies and obviously not representative of the industry as a whole, but is an indicator of what to expect when regulations are fully implemented by 2015.
"We know that immediate methane reductions are critical to slow climate change," said Fred Krupp, president of EDF. "But we don't yet have a handle on how much is being emitted. We need better data, and that's what this series of studies will deliver. As we understand the scope of what's happening across the natural gas system, we will be able to address it. We already know enough to get started reducing emissions, and thanks to the first study, we know that new EPA regulations to reduce wellhead emissions are effective. EPA got it right."
One last comment (for now) about the EPA regulations this time from Dr. Robert Horwath, professor at Cornell University, who first published a peer-reviewed assessment of the greenhouse gas footprint of shale gas back in 2011. On the discrepancy between the UT Austin/EDF study data and other studies that see significantly higher methane emissions:
How can we explain this huge discrepancy? My take at the moment – again without access to the data sources and analysis behind the Allen et al. paper – is that the gas industry can produce gas with relatively low emissions, but they very often do not do so. They do better when they know they are being carefully watched. When measurements are made at sites the industry chooses and at times the industry allows, emissions are lower than the norm. But the norm may well be 10-fold or more higher, based on the other accumulating research by NOAA and other independent researchers.
The UT Austin study is the first of 16 studies that will look at all aspects of the natural gas system and quantify methane emissions.