Isometric has released the draft Orphaned Well Plugging (OWP) Protocol for public consultation. The protocol outlines requirements and procedures for projects that permanently plug leaking orphaned oil and gas wells in the United States and Canada, stopping methane from escaping into the atmosphere.
Orphaned well plugging
An orphaned well is an oil or gas well that no longer has an operator responsible for its maintenance or closure, often due to insolvency. There are more than 141,000 documented orphaned wells across 29 US states alone, and up to an additional 740,000 that are undocumented.
Many of these orphaned wells have been left unplugged, meaning that they can leak methane, a potent greenhouse gas, from the wellbore into the atmosphere. Orphaned well plugging projects seal the wellbore, typically with cement, to permanently stop that methane from escaping.
The backlog of orphaned wells across the US and Canada exceeds what public programs can plug, and methane emissions are rarely what decides which wells are closed first. Certifying the reductions from plugging funds work that prioritizes wells leaking methane into the atmosphere.
The Orphaned Well Plugging Protocol
The OWP Protocol sets out how emission reductions from plugging orphaned wells in the US and Canada are measured, certified, and monitored. To be eligible, projects must demonstrate that a well is orphaned, is not scheduled for plugging by a public program, and would not have been plugged without carbon finance. Projects must also have the landowner’s consent and the operating rights needed to plug the well.
The protocol requires each project to take a direct, on-site measurement of the well’s as-found methane leak before plugging. The well’s emissions are then projected forward over a 20-year crediting period using a conservative decline rate. Projects must demonstrate, through an engineering analysis, that the underlying reservoir holds enough gas to keep leaking at the measured rate over the crediting period.
Left unplugged, some wells leak more over time as the wellhead equipment corrodes. Projects can claim a capped rise in the baseline leak rate to reflect this, but only when it is evidenced by a corrosion model and supported by the reservoir engineering analysis.
Every plugged well must pass a permanence check 12 to 18 months after plugging, and a portion of certificates is withheld until the check confirms the well is sealed. Projects must meet environmental and social safeguards aligned with the ICVCM Core Carbon Principles, including restoring the well site to a condition consistent with the surrounding land use.
The OWP Protocol was developed by Isometric’s Science Team with reviewers from the Science Network, an independent group of more than 500 academic experts. Its development was part-funded by three orphaned well project developers, CH4mber Technologies, Rebellion Energy Solutions, and Zefiro Methane Corp..
Oliver Chornous, Co-founder and CFO of CH4mber, said: “We’re glad to be aligned with Isometric on this protocol. It matches what we found over three years of on-site research at more than 5,000 wells, in collaboration with partners in industry, regulation, and academia, which is that you should only credit the methane a well is measured emitting. At current rates, without carbon markets, these wells will remain unplugged for centuries. This gives private capital an auditable path to plug the leakiest wells first, putting every molecule to maximum impact on near-term warming.”
Staci Taruscio, CEO of Rebellion, said: "Rebellion is pleased to contribute to the understanding of how to effectively assess, measure, and account for orphan well methane emissions. With this new methodology, buyers will be armed with the confidence to invest in the plugging of orphan oil and gas wells, and all of the community and land benefits that follow. Once plugged, the positive effects span from hyperlocal biodiversity increase through the health and safety of communities to global climate impact. We look forward to continuing to educate and unify alongside partners in the VCM willing to tackle this solvable but pressing climate issue."
Sam Jennings, Director of Carbon Operations at Zefiro, said: “We appreciate Isometric’s work to advance carbon finance for orphaned well plugging and welcome this public consultation. Credible methane credits depend on measurable, verifiable reductions grounded in field measurements of actual leakage and defensible projections of future emissions. A framework that combines scientific rigor with the practical requirements of financing and delivering well-plugging projects can help attract the investment needed to plug more leaking orphaned wells.”
As with all Isometric protocols, every scientific and methodological decision was made by the Science Team. Funding does not influence a protocol’s requirements, and certificates are only issued where an independent accredited auditor has confirmed a project is compliant.
Isometric welcomes comments during the 30-day public consultation period ending on November 14, 2026.
