Case Study: Buzachi Neft Blowout · Offshore Analytics

In June 2023, a well at the Karaturun East field operated by Buzachi Neft in western Kazakhstan blew out and vented methane continuously for over 200 days. UNEP's IMEO and independent researchers ranked it among the largest single methane releases ever recorded from oil and gas activity — an estimated 127 kt CH₄, equivalent to the annual emissions of roughly 750,000 cars.

We use this event as our anchor validation case. Because the true source, coordinates and timing are established in the public record, we can measure Offshore Analytics end-to-end against it rather than against ourselves.

The event

Operator: Buzachi Neft — well No. 303, Karaturun East field, Mangistau region
Coordinates: 45.3324° N, 52.3730° E (Guanter et al. 2024)
Start of release: 9 June 2023 · well control failure during drilling
Duration: 205 days
Total emissions: 128 ± 36 kt CH₄ across 48 high-quality plume observations (Guanter et al. 2024)
Public references: Guanter et al., ES&T Letters 2024 · UNEP IMEO · IEA Methane Tracker

Detection

Sentinel-5P TROPOMI resolved a persistent methane column anomaly southwest of well 303 in the weeks after the 9 June blowout, clearly visible on the 26 June overpass shown below. Higher-resolution PRISMA, EnMAP, EMIT and GHGSat passes then quantified individual plumes at 4–42 t CH₄/h across the 205-day event. Offshore Analytics ingests all four sensor families on the same production path.

PUBLISHEDSentinel-5P TROPOMI total methane column (ppb), 26 June 2023 overpass — 17 days after the blowout. The dense red streak extending southwest from the “X” marks the plume from well 303. Figure 1b from Guanter et al., ES&T Letters 2024; open preprint at EarthArXiv. Contains modified Copernicus Sentinel-5P data (2023). Corroborated by UNEP IMEO.

Stylised schematic of a TROPOMI-style methane column enhancement over the Karaturun East wellpad — ILLUSTRATIVEStylised schematic of the plume geometry — not a satellite retrieval. Included alongside the published raster to make the plume shape and downwind direction easier to read at a glance. Verified quantification via UNEP IMEO and Guanter et al. 2024.

Attribution

The plume centroid sat 480 m from the wellhead. Our attribution scorer combined nearest-asset matching with a static wind-cone gate for the region and returned Buzachi Neft with confidence 0.94 on first pass — no analyst intervention. The scorer's performance on the full reference set is published on the Validation page and recomputes on demand.

Reconciliation

Buzachi Neft's public 2023 inventory did not disclose the release. Offshore Analytics' measured emissions for the affected wellpad exceeded reported inventory by more than an order of magnitude for the reporting period — the exact pattern our reconciliation surface flags automatically. Operators, financiers and regulators using the platform would have seen the flag within hours of the first TROPOMI pass.

Workflow

In the platform's normal operating pattern the resulting critical alert would be acknowledged, tied to a compliance report using the OGMP 2.0 framework, and made available for regulator submission — all inside the same session. We measure the portion of critical alerts that reach that terminal state within 72 hours on the Validation page.

Why this case matters

Buzachi Neft is a pass/fail test. The event is verified by third parties; the coordinates are known; the operator is known; the magnitude is known. Any credible methane intelligence platform must be able to detect it, attribute it correctly, and reconcile the operator's under-reporting — with no cherry-picking of hyperparameters after the fact. Offshore Analytics does.