Concerned groups like the Environmental Defense Fund (EDF) are raising new greenhouse gas (GHG) emissions concerns related to the North American natural gas production boom, citing a new paper on methane leakage in Utah's Uintah Basin released Monday by researchers at the National Oceanic and Atmospheric Administration (NOAA) and University of Colorado.
Published in the journal Geophysical Research Letters, the paper reported methane emissions as high as 14% of total production in a 1,000-square-mile area in the Uintah. The findings are based on readings from airplane flights that measured methane in the air on a single day and estimated the proportion of those emissions that came from oil and gas infrastructure, including production, gathering systems, processing and transmission of gas out of the region.
There is calculated uncertainty to the report's numbers, as acknowledged by the authors from the University of Colorado's Cooperative Institute for Research in Environmental Sciences and NOAA's Earth System Research Laboratory in Boulder. They said there is a 68% chance that the leak rates are between 6.2% and 11.7%, and a 95% chance the rates are 3.5% to 14%.
According to EDF, there is no clear data identifying where the emissions are coming from, and that is why the environmental group is leading an effort to complete a series of studies across the nation by the end of next year. Last year, Garfield County, CO, launched a gas drilling emissions study with university researchers (see Daily GPI, Aug. 22, 2012).
"More investigative work is needed before we can claim to understand what is driving these apparently large emissions," an EDF spokesperson said. "We don't know everything we need to about the production and distribution practices employed in the Uintah Basin when this research took place."
Last May, scientists at the same organizations reported a 17% methane leak rate for the Los Angeles Basin, and in 2008, there was a 4% methane leak rate in the Denver-Julesburg Basin's oil/gas field near Denver.
"Taken together, these studies are troubling," said an EDF spokesperson. "They should be regarded as alarm bells ringing in our ears, and action by policymakers and industry is needed now."
The authors' said that methane emissions from natural gas production typically are not well quantified and have the "potential to offset the climate benefits of natural gas over other fossil fuels." They used a "mass balance approach" to estimate the methane emissions from a gas and oil production field in Uintah County, UT on Feb. 3, 2012.