Breakthrough Moment: Satellite Identifies, Measures Methane from Gas Well Blowout

(NEW YORK, NY) Scientists announced today that they have successfully used data from an orbiting satellite to not only identify, but also measure methane surging from a major blowout at an Ohio natural gas well last year. Published in the Proceedings of the National Academy of Sciences, the results mark a breakthrough for a burgeoning technology and the growing list of public, private and non-profit ventures aiming to use satellites to track and reduce otherwise-invisible methane emissions from the oil and gas and other industries worldwide.

Readings were taken by the TROPOMI instrument, launched by the European Space Agency just a few months before the event. It is the first time methane from an oil or gas incident has been both detected and quantified using satellite data gathered during a routine global survey.

"Methane emissions are a huge contributor to climate change. But source locations are often unpredictable and can occur in out-of-the-way places all over the globe. These new results show the opportunity for satellites to help see and quantify emissions no matter where they are," said report co-author Dr. Steven Hamburg, Chief Scientist at Environmental Defense Fund. "Regular, widespread data like this offers an invaluable tool for industry and public officials alike to understand problems and identify effective solutions." 

Along with EDF's Dr. Ritesh Gautam, the other co-authors include scientists from SRON Netherlands Institute for Space Research; Vrije Universiteit Amsterdam; the Netherlands Organization for Applied Scientific Research (TNO) and Utrecht University.

Hamburg is also the project co-lead for the EDF subsidiary MethaneSAT, which is scheduled to launch a new satellite of its own in 2022 that will measure methane from oil and gas regions across the globe weekly, identifying and quantifying smaller emission events and more widely dispersed sources not discernable with current technology.

Surprise explosion and an emissions mystery

On Feb. 15, 2018, an explosion occurred at a new well in Belmont County, Ohio. The blowout led to the uncontrolled release of natural gas (which is mostly methane) for the next 20 days. While operators and officials knew at the time that it was a major incident, the actual volume of gas released was not directly measured. 

On first learning of the situation, Dr. Gautam asked the Dutch SRON TROPOMI team headed by Dr. Ilse Aben at SRON whether their newly commissioned system might have captured it. TROPOMI data gathered on Feb. 27, the 13th day of the event, showed that the damaged well was pumping out approximately 120 tons of methane per hour, which is twice the peak emission rate of the widely-reported Aliso Canyon event in California in 2015.

Assuming the observed rate reflected an average for the 20-day period, total emissions from the Ohio event would have totaled about 60,000 tons. That figure is comparable to one-quarter of the entire state of Ohio's reported annual oil and gas methane emissions.

Spotlighting a valuable tool

Successful quantification of the Ohio blowout demonstrates the growing opportunity for satellite remote sensing to provide robust and regular accounting of methane emissions worldwide. Methane is a potent greenhouse gas, human-made methane emissions of which are responsible for more than a quarter of the warming we're experiencing today. Because they have historically been difficult to measure, methane emissions are often underreported.

For example, a five-year series of studies organized by EDF recently concluded that emissions from the U.S. oil and gas sector were a full sixty percent higher than EPA estimates. Research has also shown that large, unpredictable events — referred to in the literature as "super-emitters," of which the Ohio incident was an extreme case — are responsible for a disproportionate share of total oil and gas methane emissions. But these emissions have generally not been included in EPA inventories.

These factors underscore the importance of regular, widespread monitoring and measurement, and explain the rapidly growing interest in space-based instruments, which have the potential to provide comprehensive estimates of methane emissions, how much and where. 

"TROPOMI is part of an emerging ecosystem of methane-tracking satellites that will offer a growing range of specialized capabilities. Together, these systems are going to play a crucial role as companies, countries and stakeholders work to cut emissions of this potent greenhouse gas," EDF's Gautam said.