• Sanction follows extensive engagement and repeated warnings
• NSTA urges operators to plug and abandon redundant wells to protect the environment and the public purse
• Decom costs will rise if unused supply chain moves overseas
• The North Sea Transition Authority (NSTA) has today fined North Sea licensee EnQuest Heather Limited a collective total of £16.5 million for failing to decommission 33 inactive wells.

Timely decommissioning is essential to protect the wider environment, prevent extra costs to the taxpayer and support jobs in the supply chain.

The cumulative fine is for protracted non-compliance on 33 wells under four separate licences on Alma, Galia, Broom, and Dons fields. The penalty for each breach is £500,000.

The Alma, Galia, Broom, and Dons fields ceased production between summer 2020 and spring 2021. The 33 wells, which are the subject of the fines have been awaiting decommissioning since this time. Decommissioning is the final step of the process and is only required when a well, or other piece of infrastructure, has no further use.

The NSTA is determined to support production and energy security. It works with the industry to support production from reservoirs and highlights tools to optimise production, as well as encouraging work to extend the life of existing wells through targeted interventions. But it is important that, once all other viable options have been exhausted, wells are properly decommissioned. 

The NSTA has repeatedly warned operators that delaying this work could increase the cost to the Exchequer and therefore the public, because the costs are tax-deductible, potentially resulting in significant tax refunds. Safe decommissioning is also important as the government believe it is essential for the long-term protection of the marine environment.

Stuart Payne, NSTA Chief Executive, said:
“Safe and timely decommissioning is an essential part of doing business in the North Sea. Delivering on commitments and obligations also helps to provide the reliable, steady flow of activity that our world-class supply chain has stated time and again is vital to its survival.

“Delays to decommissioning and any reduction in supply chain capacity risks adding additional costs for the UK taxpayer.

“The NSTA is focused on supporting energy security and works with operators on ensuring economic recovery. It is now, more than ever, important to ensure that the North Sea is operating efficiently and clear regulation demonstrates stability and encourages investment, which can help boost production.”

The action follows lengthy engagement with the company and an investigation which revealed that it pursued a conscious strategy to defer the costs of meeting its plugging and abandonment obligations – at a time when the wells had reached the end of their useful life. This included requesting various deadline extensions which were then missed, with a clear pattern of reneging on their own decommissioning plans.

The NSTA expects industry to spend around £27 billion between 2023-2032, more than half of the total £44bn North Sea decommissioning is estimated to cost in the 2025 UK Decommissioning Cost and Performance Update.

Well Plugging and Abandonment (P&A) represents almost 50% of that spend and there are currently around 500 wells at or beyond deadline, with more than 1,000 more expected to be due for decommissioning between 2026 and 2030. 

The NSTA has spent years developing new and innovative ways to support licensees and the supply chain to make a success of the UK's decommissioning journey. 

The NSTA has acted as a convening force, regularly connecting licensees with each other in areas of mutual interest, and with the supply chain to open new opportunities for partnership and efficiency.

The NSTA has used data and technology to unlock value for industry, developing the Visibility Dashboard that publishes the majority of licensees' five-year plans, creating TWIST, a tool which provides access to data on subsea well infrastructure, helping companies plan their decommissioning projects better and quickly locate hard-to-find tools.

In December 2025, following industry consultation, the NSTA published information on operator performance regarding well decommissioning obligations, in a further effort to drive for improved compliance and encourage activity across the basin.

As well as these and many other interventions to support and enable, the NSTA is also required to step up and act in the face of continued non-compliance, and that is what it has done today.

KeyFacts Energy: EnQuest UK country profile