Methane leak rates from gas fields in Texas, Louisiana, Arkansas and Pennsylvania, at about 1 percent, are lower than some previous estimates, according to a new study by University of Colorado researchers.
Using sophisticated measurements taken from aircraft, the researchers assayed methane emissions on five flights over natural gas basins in 2013.
While the scans showed tens of thousands of pounds of methane leaking each hour from some equipment, the overall leak rate was calculated at around 1 percent. The research was a joint-venture of the Cooperative Institute for Research in Boulder and the National Oceanic and Atmospheric Administration.
The federal Environmental Protection Agency, using inventories from oil and gas operators, has estimated the leak rate at 1.8 percent. But studies in Utah, Colorado, Texas and Pennsylvania, including some done by CIRES researchers, indicated the rates might be two to six times higher.
Another Lawrence Berkley National Laboratory study found human-produced methane up to 1.7 times higher than EPA estimates.
“We are beginning to get a sense of regional variation in methane emissions from natural gas production,” said Jeff Peischl, lead author of the study and a CIRES scientist