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As much as 8% of the Uinta Basin’s natural gas production escapes into the atmosphere, an indication that the basin’s methane emissions are among the worst in the nation for energy-producing regions, according to new research from the University of Utah.
Monitoring data indicate leaks from wells, pipelines, compressors and processing facilities release 6 to 8% of the natural gas pulled from the ground in northeastern Utah, representing a huge waste of a largely publicly owned natural resource. These “fugitive” emissions also pose an avoidable threat to the climate. That’s because methane, the main ingredient in natural gas, has a much stronger greenhouse effect than carbon dioxide.
An estimated 2.3% of U.S. natural gas production escapes into the atmosphere, according to other research, accounting for 30% of the nation’s human-caused methane emissions. Other leading sources include coal mines, landfills and possibly bovine flatulence.
The Biden administration highlighted “methane abatement” as one of its strategies for achieving its goal of cutting the nation’s 2005 greenhouse emissions in half by 2030. On Nov. 2, the Environmental Protection Agency proposed tighter standards and guidelines for reducing methane emissions from oil and gas operations. These rules would cut emissions by 41 million tons through 2035, the agency said.
Despite the severity of methane’s impact, quantifying these fugitive emissions has been elusive. Labor-intensive methods of surveying oil and gas sites for leaks has proven unreliable. But a research team led by John Lin, a U. atmospheric scientist, is now using long-term monitoring data to determine how much methane escapes from the Uinta Basin’s oil and gas operations.
According to a peer-reviewed study released this week in Scientific Reports, Lin’s team documented how the basin’s methane emissions dropped by half since 2015, in virtual lockstep with declining natural gas production over the same period when commodity prices tanked.
“This means that the leak rate has stayed at a constant—albeit high—rate, even with decreases in natural gas production,” Lin said. Previous research suggested lower-production wells would leak a higher proportion of methane.
“This may account for the high leak rate in general in the Uinta Basin since the average Uinta well produces less gas compared to many other counterparts around the U.S.,” Lin said. “However, it was nonetheless surprising that the leak rate did not increase as the Uinta wells decreased in production.”
His findings support similar findings from eight years ago by the National Oceanic and Atmospheric Administration, or NOAA, which estimated that 6 to 12% of the basin’s production leaked into the air.
That study was based on a one-day snapshot based on air samples gathered during overflights.
The new study, by contrast, is a look at methane levels over time as recorded by monitoring stations installed by NOAA in 2015, which record ambient levels of methane in three locations. While just six years old, this land-based monitoring program is the nation’s oldest specifically installed to measure methane levels in an oil-and-gas-producing region.
The westernmost monitoring station in Fruitland was established to record baseline levels, while the eastern one is in Uintah County’s gas-producing hotspot south of Vernal known as Horsepool. The middle one is at Castle Peak in Duchesne County, a stronghold for oil. Methane comes up as a byproduct in crude production and is often flared at the wellhead.
Not surprisingly, the highest levels of methane were recorded at the Horsepool site.
The standard volumetric unit of natural gas is 1,000 cubic feet, or mcf.
During the study period, natural gas production dropped in the basin from 320 million mcf to 190 million as drilling tapered off. At current spot prices of about $5 an mcf, the value of the gas lost this year would be $57 to $75 million.
“An effort to reduce such CH4 [methane] leaks from the oil/gas infrastructure would not only yield climate benefits,” the study states, “but could also help the energy industry recoup at least some of its cost invested in leak detection and repair by recovering an economically valuable product.”
It would also improve local air quality.
In the Uinta Basin, methane is emitted with organic compounds, precursors to ozone formation, which results in markedly high levels of ozone.
“Besides the obvious and more important health impacts to residents of the basin, air quality problems lead to increased regulation of oil and gas development, which increases costs, and those costs are passed on to consumers,” said co-author Seth Lyman, director of Utah State University’s Bingham Energy Research Center in Vernal.
Natural gas can leak from countless places as it moves through the supply chain from the wellhead to homes. Aside from the wells and pipelines, gas leaks from dehydrators, gathering and compression stations, pneumatic controllers and from equipment that handles liquid hydrocarbons, such as loaders and storage tanks.
Lin said leak-detection technologies, such as drones and infrared imagery, have improved in recent years, so the methane emissions may not necessarily increase if the basin’s production rebounds in the wake of a price surge now underway.
“This will depend on decisions made by individual companies, as well as on changes that have occurred or that may occur in the regulatory landscape,” Lyman said.