Tier-3 Methane MRV: what the NUPRC deadline actually requires
A plain-English explainer on the shift from estimated to measured methane reporting — what Tier 3 means, why it's hard, and how to tell if you're ready.
The regulatory direction of travel is clear: methane reporting is moving from estimated to measured. This piece is a plain-English explainer of what that shift means in practice — written for the HSE lead and the operations manager who have to deliver it, not the policy team.
This is an educational overview, not legal or regulatory advice. Always work from the current gazetted requirements and your own competent person.
The tiers, in one paragraph
The "tier" describes how a number is produced, not how big it is. Tier 1 uses generic emission factors. Tier 2 uses facility-specific factors and engineering estimates. Tier 3 is measurement-based — quantification at the source, reconciled with independent observation. Each tier up is a step from plausible toward defensible.
Why Tier 3 is hard
Most operators don't fail Tier 3 on intent. They fail on the four things it actually requires:
- Continuous measurement on material sources — not once-a-year estimates.
- OGI and closed-loop LDAR — optical gas imaging plus a documented detect-to-repair workflow that you can prove.
- Metered flaring and venting — flaring is often the single largest reported source, and an estimate there undermines the whole inventory.
- Auditable reporting — every reported figure traceable back to a measurement.
A quick way to think about readiness
A useful mental model: for each major source, can you answer "how do you know that number, and can you show your working?" If the honest answer is "we estimated it," that source isn't Tier-3-ready yet.
Reconciliation: the part teams forget
Bottom-up inventories miss things. Public satellite methane data (for example Sentinel-5P / TROPOMI) lets you cross-check your inventory against what's actually observed over your sites — so an unexplained plume is something you catch first, not a regulator or an NGO.
Where to start
Start with your largest sources and work down. Measurement coverage where the emissions actually are buys you the most defensibility per naira spent. Then formalise LDAR, meter your flares, and move reporting onto a workflow that assembles the report from source data with a clear lineage.
Want to see where you stand? The MRV readiness check gives you a band and a gap list in about two minutes.