Uncapped and inactive oil wells could release millions of kilograms of methane into the atmosphere and surface water each year, according to a University of Cincinnati study.
Amy Townsend-Small, associate professor of geology and geography at UC’s College of Arts and Sciences, studied 37 wells on private property in the Permian Basin of Texas, the largest oil producing region on Earth. She found that seven had methane emissions of up to 132 grams per hour. The average rate was 6.2 grams per hour.
“Some of them were leaking a lot. Most of them were leaking little or not at all, which is a pattern we have seen throughout the oil and gas supply chain,” Townsend-Small said. . “A few sources are responsible for most of the leaks.”
The study, published in the journal Environmental research letters, is the first of its kind on methane emissions from idle oil wells in Texas.
“No one has ever had access to these wells in Texas,” Townsend-Small said. “In my previous studies, the wells were all on public land.”
A 2016 study by Townsend-Small found a similar problem in inactive wells it tested in Colorado, Wyoming, Ohio, and Utah. Spread over the 3.1 million abandoned wells, the leaking methane is equivalent to burning more than 16 million barrels of oil, according to government estimates.
Five of the inactive wells studied by Townsend-Small in Texas were leaking a brine solution onto the ground, in some cases creating large ponds.
“I was horrified by it. I’ve never seen anything like it here in Ohio,” Townsend-Small said. “One was spouting so much water that the people who lived there called it a lake, but it’s poisonous. There are dead trees all around and it smells of hydrogen sulfide.”
Most of the wells had been inactive for three to five years, possibly due to fluctuations in market demand. Inactive wells could be a significant source of methane emissions if they are not subject to leak detection and repair regulations, the UC study concluded.
The study was funded in part by a grant from the US Department of the Interior.
Previous studies have shown that the basin generates 2.7 billion kilograms of methane per year, or nearly 4% of the total gas extracted. This is 60% higher than the average methane emissions in oil and gas producing regions nationwide. This has been attributed to the high rates of ventilation and flaring due to the lack of gas pipelines and other gas production infrastructure.
Methane is a powerful greenhouse gas that scientists have linked to climate change. If the rate of methane leaks observed by UC were constant in the 102,000 unused wells in Texas, the 5.5 million kilograms of methane released would be equivalent to burning 150 million pounds of coal each year, according to an estimate by Grist magazine. and the Texas Observer nonprofit news organization.
Townsend-Small and his undergraduate research assistant at UC Jacob Hoschouer, co-author of the study, came to Texas at the suggestion of media organizations, who wanted to explore the environmental impact of oil wells, in especially those who are inactive or abandoned. An expert on methane emissions, Townsend-Small has studied releases from oil and natural gas wells across the country.
Journalists arranged with the owners to have Townsend-Small examine the wells.
President Joe Biden’s administration has pledged $ 16 billion in its infrastructure plan to cap abandoned oil and gas wells and mitigate abandoned mines. Hoschouer said it would be gratifying if their research could help regulators prioritize which wells to style.
In the meantime, regular inspections of inactive wells using infrared cameras to identify leaks could solve the problem, the UC study suggested.
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Material provided by University of Cincinnati. Original written by Michael Miller. Note: Content can be changed for style and length.