Permian Study Finds Overproduction Leading to More Methane Leaks
(Bloomberg) -- The energy-rich region of the southwestern U.S. known to geologists and fossil fuel enthusiasts as the Permian Basin has expanded its production more quickly than any other oil and gas region in recent years, reaching 38% of U.S. oil and 17% of gas production in 2020. With this scale has come a gush of greenhouse gas emissions, although just how much has until recently been impossible to say.
Between September and November 2019, a team of scientists from the NASA Jet Propulsion Laboratory, the University of Arizona, and Arizona State University flew multiple times over the 21,000 square miles of the Permian Basin with airplanes bearing sensors that allowed them to pinpoint “super-emitters” of methane. About 29% of the total lost gas quantified in flyovers between September and November 2019 came from “routinely persistent” sources, indicating that these leaks could be largely eliminated with repairs and diligent monitoring. The releases represented just 11% of emissions sites from a total of 1,100 unique sources studied.
While carbon dioxide is a bigger driver of global warming and lasts longer in the atmosphere, methane—the main component of natural gas—traps more than 80 times as much heat over a 20-year period. Halting methane emissions from the oil and gas industry has jumped to the top of climate to-do lists in part because policy analysts have identified it as one of the cheapest and easiest ways to hold down global temperatures.
Leak detection—which for decades relied on techniques like spraying soap onto pipes or throwing a tarp over equipment to check for fugitive gas flows—is finally entering the digital age, with satellites, drones, and other aircraft promising a new era of climate transparency. By conducting multiple flights at altitudes of 2 miles and 5 miles, NASA scientists were able to document whether the methane emitted from each site was continuous or episodic. Knowing how long each event went on helped them estimate which part of the oil-and-gas production process the methane escaped from. Half the emissions came from production facilities, including the wells sites themselves and tanks associated with them. Another 38% came from pipelines and gas compression infrastructure, and 12% from processing plants.
The 1,100 sites where the scientists detected emissions make up about 1.4% of the area’s production facilities. By contrast, only about 0.2% of facilities in California were found to be the source of methane plumes. Emissions persist for about the same amount of time in each area, the authors write, but they found more of them in the Permian basin, emitting three times more methane than those in California.
Midstream operations in the Permian, according to the new data, make up about 20% more of the basin’s overall methane total than was expected from previous studies. That result is consistent with the researchers’ hypothesis that high production rates were causing bottlenecks farther down the supply chain, leading to more venting and incomplete flaring.
Flaring—the practice of burning off gas so that it enters the atmosphere as CO₂ not CH₄—can occur at several points in production and may not reduce emissions from the Permian as much as previously thought. The U.S. Environmental Protection Agency estimates that flaring typically cuts methane by 98%, a number that’s not supported by this study, nor by studies of other regions.
The nonprofit Environmental Defense Fund has incorporated the NASA and University of Arizona data into its Permian Methane Analysis Project, tagging each oil-and-gas site by company. Meanwhile Ceres, a nonprofit that promotes capital markets as critical to cleaning up energy, and Clean Air Task Force, a policy research nonprofit, also this week published a report and data explorer documenting and comparing the emissions of nearly 300 of the top U.S. oil-and-gas producers who report data to the Environmental Protection Agency. They found that small companies who make up 9% of production are responsible for 22% of the sector’s emissions. At the other end of the scale, the biggest seven producers make up a quarter of all emissions.
The airplane survey research was funded by NASA, the University of Arizona, the High Tide Foundation, and Carbon Mapper Inc., a nonprofit that has received funding from Bloomberg Philanthropies, the charitable organization founded by Michael Bloomberg, founder and majority owner of Bloomberg News parent company Bloomberg LP.
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