“Over the years we’ve invested significantly in our field data team - focusing on producing trusted ratings. While this ensures the accuracy of our Ratings, it doesn’t allow the scale across the thousands of projects that buyers are considering.”
For more information on carbon credit procurement trends, read our "Key Takeaways for 2025" article. We share five, data-backed tips to improve your procurement strategy.
One more thing: Connect to Supply customers also get access to the rest of Sylvera's tools. That means you can easily see project ratings and evaluate an individual project's strengths, procure quality carbon credits, and even monitor project activity (particularly if you’ve invested at the pre-issuance stage.)
Book a free demo of Sylvera to see our platform's procurement and reporting features in action.
Orphaned oil and gas (OOG) wells are unplugged, abandoned wells with no solvent responsible owner, and they present a significant and often underestimated source of methane emissions, leaking continuously for decades if left unsealed.
Sylvera’s new framework evaluates OOG carbon projects, that aim to reduce these emissions by permanently sealing leaking wells, across four pillars: Carbon Accounting, Additionality, Permanence, and Safeguarding & Co-benefits, using a data-driven, methodology-agnostic approach.
Download the Orphan Oil & Gas Well (OOG) Ratings Framework here.
What are Orphan Oil and Gas Well carbon projects?
Across the world, millions of oil and gas wells have reached the end of their productive lives. Many have been properly sealed. But a significant subset, known as orphaned wells, have been left unplugged, with no solvent owner to take responsibility for their closure.
Orphaned oil and gas wells are unplugged, abandoned wells with no legally responsible operator. Without intervention, these wells can leak methane, volatile organic compounds, and other hazardous gases into the atmosphere for decades.
Methane is a greenhouse gas with more than 80 times the warming impact of CO₂ over a 20-year period, making orphaned wells a disproportionately powerful climate risk.
OOG well-plugging projects address this problem directly. They identify leaking orphaned wells and permanently seal them through a process known as plug and abandon (P&A): removing wellhead equipment, placing cement plugs at appropriate depths, and remediating the well site.
By stopping ongoing methane emissions, these projects contribute to near-term climate mitigation while also delivering tangible benefits to surrounding communities and ecosystems.
The OOG carbon credit market
The voluntary carbon market has emerged as a critical financing mechanism for orphaned well plugging. Governments in the United States and Canada have documented over 120,000 orphaned wells and estimate there could be ten times more that are undocumented.
Plugging costs can range from thousands to hundreds of thousands of dollars per well, and public funding has consistently fallen short of the scale required; even after major federal investments, researchers estimate the cost to plug known US orphaned wells exceeds available funding by 30–80%.
This funding gap creates a strong case for additionality. Orphaned wells lack a solvent owner, carry no economic value, and sit outside active production systems, meaning the carbon market is often the only viable mechanism to finance their remediation.
Demand for high-integrity methane reduction credits is growing. Corporates and investors are increasingly seeking near-term, measurable climate impact, and orphaned well projects offer that: immediate emission reductions with well-understood climate benefits.
As of early 2026, the VCM had issued over 8.3 million credits from 80 registered OOG projects, with new methodologies from multiple standard-setters continuing to emerge.
However, the market faces complexity:
- Methane emissions from orphaned wells are variable and intermittent, making accurate quantification challenging.
- Crediting methodologies differ in how they model baseline emissions, apply terminal decline rates, and select global warming potential (GWP) values.
- Questions around plug permanence, interwell methane migration, and post-plugging monitoring standards are still being resolved by the scientific community.
These inconsistencies create genuine uncertainty for buyers trying to assess the quality of credits.
Sylvera's Orphan Oil and Gas Well Plugging Framework
To bring clarity and confidence to this evolving market, Sylvera has developed a new OOG Well Plugging Ratings Framework.
Download the Orphan Oil & Gas Well (OOG) Ratings Framework here.
Our framework evaluates OOG projects using the same rigorous, data-driven approach that underpins all of Sylvera's Ratings: assessing not just what a project claims to achieve, but whether those claims hold up to independent scrutiny.
The framework is methodology-agnostic, relying on independent benchmarks for repeatability and consistency across projects. It evaluates four pillars:
Carbon Accounting, which assesses whether a project's reported emission reductions are accurate and conservative. This covers both carbon modeling risk, including how the project applies terminal decline rates and selects its GWP value; and project reporting, including the rigour of pre-plugging leak measurements, the comprehensiveness of project emissions inclusion, and the quality of post-plugging verification.
The current version of this framework does not cover in-line (direct-connect) measurement methods. Sylvera is in active engagement with industry and technical experts to better understand implications of this approach for carbon accounting, and will update the framework accordingly.
Additionality, which assesses whether emission reductions go beyond what would have occurred in a business-as-usual scenario. Orphaned wells generally present low additionality risk, given their lack of a solvent owner and the chronic underfunding of government plugging programs. The framework evaluates financial additionality, common practice in the project region, along with the project’s proposed baseline scenario credibility, as well as the effectiveness of any policy or regulatory frameworks that may already incentivise plugging.
Permanence, which reflects the risk that emission reductions are later reversed. OOG projects face permanence risks through two pathways: physical leakage through the plugged well itself, and interwell migration, the risk that methane migrates through the subsurface to escape via nearby unplugged wells. The framework assesses well integrity risk (including cement quality, well type, and ongoing monitoring), interwell migration risk (using Sylvera's independent geospatial well assessment within a 1km radius), and anthropogenic risks, including regional exploration activity and project team track record.
Safeguarding & Co-benefits, which evaluates the likelihood and extent of beyond-carbon benefits to communities and biodiversity. OOG well-plugging projects can generate some additional positive impacts, including improved air quality, groundwater protection, local employment, and land restoration; however, co-benefits are generally lower compared to those of nature-based solution projects, such as ARR and REDD. The framework assesses community safeguards, biodiversity impacts, and contributions to relevant UN Sustainable Development Goals.
The framework has been developed by a multidisciplinary team of internal and external specialists in well-plugging engineering, methane measurement, carbon accounting, and lifecycle analysis. It has undergone independent peer review and oversight by an external Framework Review Committee comprising scientific experts, project developers, policymakers, and carbon credit buyers.
Engagement with the industry
At Sylvera, transparency and collaboration are central to how we produce ratings. We work closely with OOG project developers to gather up-to-date information on project activities, plugging documentation, measurement records, and financial models.
View the OOG Ratings Framework
Download the Orphan Oil & Gas Well (OOG) Ratings Framework here.
