Great Britain’s regulator, the North Sea Transition Authority (NSTA), has signaled its readiness to tackle the decommissioning deficit on the UK Continental Shelf (UKCS) by revealing the names of operators that are lagging behind their peers in the decommissioning department.
The NSTA’s first published table of the North Sea well decommissioning deficit shows that 13 operators have missed their consent deadlines for fully decommissioning 153 inactive wells, which are spread geographically from West of Shetland to the Southern North Sea and East Irish Sea, with the greatest concentration in the Central North Sea.
On the other hand, 22 operators, of which nine are licensees, operating 780 wells, are in compliance with their consent deadlines. The NSTA’s decision to publish the names follows a transparency consultation , where it was suggested that companies should be named at the opening of an investigation, instead of only when sanctions are imposed, as was previously the case.
The consultation also proposed that information about companies that fall behind in decommissioning obligations should be published. An inactive well is classified as being out of consent if the operator has not applied for and been granted consent or if consent was granted, but the operator failed to decommission the well within the consented timeframe.
Pauline Innes , NSTA Director of Supply Chain and Decommissioning, commented: “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.”
The NSTA’s latest ‘Decommissioning Cost and Performance Update,’ published in July 2025, estimated that £44 billion ($58.1 billion) remains to be spent on decommissioning North Sea infrastructure, with well plugging and abandonment making up about half of the total.
The UK’s regulator warned operators that they need to start tackling the backlog of wells to stop rigs leaving the North Sea and stave off billions of pounds in additional costs for themselves and taxpayers.
The report recognized that while some companies were meeting their regulatory duty to decommission wells, many were falling behind. There are almost 1,000 inactive wells in the North Sea, which will need to be fully decommissioned, many of which are said to be within consent requirements.
NSTA highlighted: “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.”
Recently the NSTA announced that it had opened investigations into various companies over possible breaches of plug-and-abandon obligations. The decision to make this information available stems from the belief that visibility regarding the regulatory compliance of companies promotes confidence in the system and leads to greater compliance.
Dr. Russell Richardson , NSTA General Counsel and Company Secretary, commented: “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.”