Zefiro Methane Corp has achieved a major milestone in carbon markets by completing the first-ever sale of offsets generated from orphan oil and gas well remediation.
The company confirmed 92,956 metric tons of CO2 equivalent emissions reductions from a project in Custer County, Oklahoma, which have now been certified by the American Carbon Registry (ACR) and delivered to Mercuria Energy America, LLC under a pre-sale agreement.
The deal represents the debut of a new revenue stream for Zefiro, which already reports $24.4 million in revenue from its core environmental services operations in the first three quarters of 2025.
In addition to plugging and abandonment work across the Appalachian region, the company recently announced its first revenues from methane monitoring, including an $800,000 contract with the West Virginia Department of Environmental Protection.
A New Pathway for Funding Methane Reductions
The ACR first published its orphan well offset methodology in 2023, creating a framework for carbon credits to be issued from plugging projects.
Under the leadership of Chief Commercial Officer Tina Reine, Zefiro became one of the first companies to originate offsets under this system. The process included measuring baseline methane emissions, completing plugging and remediation work, and undergoing third-party validation to certify the results.
The ACR959 project in Oklahoma confirmed compliance in June 2025, with verification officially completed in July. The resulting credits represent measurable and permanent emissions reductions from methane, a greenhouse gas more than 80 times as potent as CO2 over a 20-year period.
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Mercuria, one of the world’s largest energy and commodities trading groups, was the buyer of the first tranche.
The credits will be transferred in four equal deliveries, with the first already completed. Mercuria said the transaction underscores its commitment to innovative pathways that directly cut oil and gas emissions while supporting customers’ net-zero goals.
For Zefiro, the deal sets a precedent for financing remediation at scale through voluntary carbon markets. By monetizing the climate benefits of plugging abandoned wells, the company aims to accelerate clean-up of thousands of leaking sites across the US while opening a new chapter in carbon offset development.
