The delinquent wells are geographically dispersed from West of Shetland to the Southern North Sea and East Irish Sea, with the highest concentration found in the Central North Sea. In contrast, 22 other operators, including nine licensees, managing 780 wells, are reported to be in full compliance with their consent deadlines. 

 This move by the NSTA follows a transparency consultation conducted between August and October 2024, which recommended naming companies earlier in the investigation process, rather than only after sanctions are imposed. The consultation also advocated for the publication of data concerning operators who are not meeting their decommissioning responsibilities. An inactive well is deemed “out of consent” if an operator has neither secured consent nor completed decommissioning within the stipulated timeframe. 

Pauline Innes, NSTA Director of Supply Chain and Decommissioning, underscored the scale of the challenge: “The number of wells in this table demonstrates the size of the task facing industry. The NSTA is well aware of the potential cost, and the logistical difficulties, but while many operators are delivering, too many are failing to meet obligations. Delays can impact on cost and cause reputational damage. It is our expectation that companies will take immediate action to improve compliance, placing contracts with the supply chain for the wells that are overdue or applying for consents where none exist.”

According to the NSTA’s latest ‘Decommissioning Cost and Performance Update,’ released in July 2025, an estimated £44 billion remains to be spent on decommissioning North Sea infrastructure. Well plugging and abandonment (P&A) accounts for approximately half of this total expenditure. The regulator has issued a stern warning to operators, urging them to address the backlog to prevent drilling rigs from leaving the North Sea, which could otherwise lead to billions of pounds in additional costs for both companies and taxpayers.

There are nearly 1,000 inactive wells in the North Sea that require full decommissioning, although many are currently within consent requirements. 

The NSTA highlighted the broader consequences of inaction, stating: “However, if operators don’t respond quickly, more deadlines will be missed, pushing operators into non-compliance, damaging the industry’s reputation, and depriving the supply chain of much needed work. Operators face higher costs by deferring or delaying their plugging and abandonment (P&A) execution if they continue to keep the supply chain waiting for work, causing further reductions in rig availability as the rig owners seek opportunities overseas, and impacting the execution of subsequent decommissioning work activities.”

The NSTA recently announced it had initiated investigations into several companies regarding potential breaches of P&A obligations. 

Dr. Russell Richardson, NSTA General Counsel and Company Secretary, commented on the new transparency measures: “Greater transparency is welcome. We hope that publishing this list today will encourage operators to continue working with us to ensure that they meet all their regulatory obligations and help to secure a level playing field on the North Sea.”