SANTA FE – A pollution survey using sensors on small airplanes to detect methane emissions across a major U.S. oil and natural gas production zone points to greater releases of the potent climate-warming gas than previously estimated by other methods, according to results published Wednesday.
Underwritten by philanthropists and the fossil fuel industry, the study examined emissions from October 2018 through January 2020 across New Mexico’s portion of the Permian Basin, one of the world’s largest sources of oil and natural gas that extends into West Texas.
The study estimated that methane emissions are equivalent to about 9% of the overall gas production in the surveyed area. That’s more than double the rate in several previous studies of the Permian Basin and national estimates by the U.S. government of natural gas lost to leaks and releases.
“The bad news is that emissions in this time and this region were as high as they are,” said Evan Sherwin, co-author of the study and a research fellow at Stanford University’s department of energy resource engineering. “The good news is it was only about 1,000 sites out of 26,000 active wells. ... It’s just a few percent that were emitting during this extensive study.”
The study arrives during a pivotal period for efforts by government regulators and industry to measure and rein in greenhouse gas emissions from oilfield infrastructure.
For more than a decade, government auditors have warned that bad data was blinding regulators to the amount of greenhouse gases being pushed into the atmosphere by the oil and gas industry’s flaring and venting.
The U.S. Environmental Protection Agency has proposed new regulations to eliminate venting at both new and existing oil wells and require companies to capture and sell gas whenever possible.
New Mexico recently adopted its own rules to limit most venting and flaring in oilfields to reduce methane emissions and environmental regulators are poised to impose new restrictions on oilfield equipment that emits smog-causing pollution.
Robert McEntyre, a spokesman for the New Mexico Oil and Gas Association, said progress already has been made to address methane emissions since surveys were conducted for the study.
“This report being 2 years old offers a snapshot in time that may not be reflective of conditions today but certainly underscores the industry priority and the industry commitment to advancing those rules that will help eventually in reducing the emissions over time,” he said. “We would certainly expect that that primary figure cited would only continue to decline.”
Plumes of methane can be detected by signature frequencies of light. Images of methane were collected by a small propeller plane flying 3,000 feet above ground over the course of 115 flight days, in the survey of New Mexico oilfields by Kairos Aerospace.
“The main advantage of airplanes is that they strike a balance between sensitivity and rapid coverage,” said Sherwin, acknowledging recent advances in satellite surveying technology. “This is the largest survey that has been used to estimate total methane emissions from a region.”
Sherwin says he and colleagues at Stanford and the University of Michigan quantified significant methane emissions not only at well sites but also pipelines where they merge. Funding came from sources including the Stanford Natural Gas Initiative, and industry consortium.
Climate scientists have warned that without immediate and steep reductions in emissions of carbon dioxide and methane, the world will miss its chance to avert the most destructive and deadliest effects of climate change.