Troll Well Blowup Forces Equinor Back to Basics

Norway's regulator orders Equinor to overhaul its P&A management system after a 930 kg gas release on the Troll field earns a Red 1 rating

4 Jun 2026

Norway's offshore safety authority has issued a formal enforcement order against Equinor following a gas release on the Troll field that the operator classified at its highest internal severity level. The incident, which drew urgent attention across the Norwegian Continental Shelf drilling community, centers on well control procedures during plug-and-abandonment operations, a category of work expanding rapidly as decommissioning activity accelerates. Havtil set a September 2026 deadline for a comprehensive management review.

On September 23, 2025, roughly 930 kilograms of gas burst onto the drill floor of Odfjell Drilling's Deepsea Bollsta rig during the permanent plugging of a Troll well. One worker, trapped in the shaker room by differential pressure, forced the door open against the pressure wave and escaped with minor injuries. The blowout preventer sealed the well within 71 seconds. With 114 people aboard at the time, Equinor rated the event a "Red 1," its most serious internal classification.

Published May 18, 2026, Havtil's investigation found the BOP had been left open during the casing cut, in direct breach of Equinor's own well integrity standards. Field crews had interpreted the requirement narrowly: where log data showed no gas behind casing, they considered valve closure unnecessary. Monitoring equipment had also been miscalibrated, allowing gas in the annulus to go undetected before the release.

Central to Havtil's findings were gaps in technology qualification, risk assessment frameworks, and field-level escalation processes, analysts said. Under the enforcement order, Equinor must submit a full assessment of its well workover and plug-and-abandonment management system, covering risk analyses, technology qualification, and escalation protocols, to Havtil by September 17, 2026. BOP closure is now required for all shallow-cut operations, regardless of log-data readings.

The NCS is entering a sustained decommissioning phase, with hundreds of aging wells across all three basins scheduled for permanent plugging over the coming decade. Havtil's order signals a markedly higher regulatory threshold for plug-and-abandonment risk management at scale. Where the gap between a written rule and its field application can turn a routine procedure into a serious incident, the September deadline carries consequences far beyond a single Troll well. The outcome may help define the compliance standards that govern Norway's well abandonment program for years ahead.