Satellite imagery has revealed that most of the methane pollution from oil and gas infrastructure in the US comes from hundreds of thousands of small wells scattered across the country – prompting calls for tougher climate regulation of low-producing oil and gas wells.
“We view the emissions from marginal wells as a major underappreciated mitigation opportunity,” says at the Environmental Defense Fund, a non-profit organisation in the US.
Last month, the administration of President Donald Trump moved to relax laws governing how methane emissions from oil and gas wells are managed, including lowering standards for emissions from marginal wells.
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But Omara’s research suggests these marginal wells should be the highest priority for methane reduction efforts, a key global climate challenge.
Together with colleagues, Omara collated methane emissions data covering more than 80 per cent of US onshore oil and gas production, sourced from the methane-spotting satellite MethaneSat, for the period May 2024 to June 2025.
The researchers then extrapolated to estimate methane emissions from oil and gas infrastructure across the contiguous US, establishing emissions rates across different production sites.
They found that marginal wells, which produce less than 15 barrels of oil equivalent per day, collectively contribute about 5 per cent to US oil and gas production. But they are responsible for about 58 per cent of all methane emissions from well sites, and 40 per cent of methane emissions across the oil and gas supply chain.
Compared with high-producing wells, these marginal wells are 10 times more polluting per unit of fuel extracted. “That is a significant contribution from a large population of very low-producing well sites across the country,” says Omara.
The study is the largest and most comprehensive of its kind and bridges a gap between top-level global emissions mapping and point-source emissions tracking from satellites, which wouldn’t pick up the low-level but constant emissions from these marginal wells.
Methane is the second most important greenhouse gas to address, behind carbon dioxide. Globally, the world is far off track to meeting an industry target to reduce methane intensity – how much methane is emitted for each unit of marketed gas – to 0.2 per cent by 2030, a promise unveiled at the COP28 climate summit in Dubai in 2023. Current methane intensity levels are about 2.9 per cent, but in some regions such as in Turkmenistan and Venezuela, methane intensity can exceed 100 per cent, . For marginal wells in the US, the emissions intensity is estimated by Omara and colleagues at 60 per cent – 300 times larger than the industry target.
Tougher regulation of these marginal wells – or even shutting the sites down altogether – offers a quick route to reducing methane emissions in the short term, without significantly denting oil and gas production overall. But at Harvard University warns this will be a difficult challenge to address because there are so many emissions sources to deal with. “The methane emissions are not coming from a few super-emitters or high-producing wells; they’re just coming from all these pieces of infrastructure littered around the landscape,” he says.
at Imperial College London says global progress towards meeting methane targets has been “very disappointing”. “Reducing methane leaks is an extremely cheap, sometimes revenue-generating form of climate action,” he points out.
“We had very much hoped that the US, as a major gas producer signed up to the methane accords, would be bringing down their wasteful gas leakage problem. Under Trump this hasn’t happened, and regulatory rollback and personnel cuts have meant that the trends are both harder to track and likely going the wrong way,” says Lamboll.
Earth Arxiv
