Extensive research effort tackles methane leaks
Better information enables data-driven solutions to dangerous climate risk
Until recently, little was known about exactly where and how much methane was emitted during oil and gas activities.
Meanwhile, national oil and gas production has been booming, with few regulations to keep air pollutants like methane in check.
How significant are these emissions to the climate, considering methane’s potent impact as a greenhouse gas?
Filling a problematic data gap
In 2012, we set out to better answer this question by launching our largest research project to date: A series of 16 independent, rigorously executed projects [PDF] designed to find out how much and from where methane is escaping into the atmosphere across the entire supply chain.
Now, as study results start to emerge, we’re learning there’s little time to waste if we want to avoid the worst impacts of climate change—yet practical, cost-effective solutions are possible now.
Collaboration has been critical
The studies examine all areas that make up the oil and gas supply chain: production; gathering lines and processing facilities; long-distance pipelines, storage, and local distribution; as well as some end users using natural gas, commercial trucks and refueling stations.
An investigation of this unprecedented magnitude required collaboration with over 125 research and industry experts.
Nearly every prominent researcher who’s working on this issue is involved.Drew Nelson EDF Senior Manager, Oil and Gas
No one tool is perfect
Measuring methane—an odorless, colorless gas that dissipates quickly—is challenging work.
And results can vary, depending on the measurement tools used, the specific conditions where research is done and the scientific assumptions made. This all adds up to a high degree of variance in reported leak rates. Our series was designed to help combine, compare or contrast methods to fuel precision, instead of confusion.
Aerial versus on the ground
For example, several studies use innovative aerial measurements taken by specially instrumented aircraft equipped with methane sensors. These “top-down” readings augment traditional “bottom-up” readings, or measurements taken directly at the potential emission source, often at ground level.
Bottom-up measurements are essential to identifying specific sources of methane pollution, but given the complexity and breadth of the oil and gas supply chain in the U.S., it’s not possible to measure all sources directly.
Top-down readings provide a snapshot of emissions over a whole region, lending important insights to the shape of emissions, while bottom-up adds the finer-grain details inside the shape.
Yet, like bottom-up tools, top-down measurements have limitations. They capture unrelated methane sources, such as landfills or wetlands, which then must be subtracted from the overall emissions data.
Together, these two methods provide greater insight and certainty than either method alone.Mark Brownstein EDF Associate VP Climate & Energy
Policy makers take notice
Thanks in part to these studies, political leaders are beginning to address the issue of methane pollution.
President Obama and his administration have taken important steps to curb this pollution, though much more remains to be done. On the state and global level, leaders are also putting forth clear plans to cut this dangerous pollutant.
Researchers directly measured methane emissions from medium- and heavy-duty vehicles fueled by natural gas, as well as refueling and maintenance facilities. The study found that the largest sources of vehicular-related methane emissions came from tailpipes (30%) and crank cases (39%). Emissions from fueling stations were relatively low, accounting for about 12% of transport segment emissions.
Researchers used a variety of techniques to measure the rate at which methane is lost to the atmosphere in Indianapolis, Indiana. The study found that natural gas end use sources – like gas meters, furnaces, boilers and hot water heaters – as well as landfills, are responsible for a large portion of urban methane emissions.
In the largest sample size of any methane study performed to date, researchers used infrared technology to conduct an aerial survey of over 8,000 well pads in seven geologic basins to characterize the prevalence of “super emitters”. The study concludes that super emitters are widespread and unpredictable, but easily identified through better and more frequent monitoring.
Summary blog post »
Details (ACS Publications) »