As many as 50 North Sea oil and gasfields could cease production this year after a collapse in crude prices to 12-year lows, industry experts have warned.

This would accelerate the North Sea’s decline, potentially bringing forward billions of pounds in spending on decommissioning.

Dozens of smaller fields with high production costs that are approaching the end of their lives have been identified by energy consultants Wood Mackenzie as prime candidates to be shut. Halting output is the first step towards abandonment.

This, in turn, could speed up decommissioning — when operators abandon fields and dismantle decades-old infrastructure, including platforms and pipelines.

Wood Mac said oil companies were likely to halt output at 140 offshore UK fields during the next five years, even if crude rebounded from $35 to $85 a barrel. This compares with just 38 new fields that are expected to be brought on stream during the same period.

Industry executives believe the decommissioning industry, still in its infancy, will grow. Royal Dutch Shell is preparing to take apart the first of four platforms in its Brent field, while Riverstone-owned Fairfield is to abandon Dunlin.

As the sector declines, service providers anticipate that decommissioning may help them plug the revenue gap left by diminishing exploration.

Fiona Legate, Wood Mac’s UK research analyst, said: “It will be a huge opportunity but the problem is the small amount of decommissioning activity to date means there is limited decommissioning experience in the UK sector. If you’re a company wanting a piece of that cake, the timing of market entry is very hard to gauge.”

To abandon one of the North Sea’s bigger platforms, and plug up to 30 wells, can cost more than £700m. As a result, even at $30 a barrel, some operators may prefer to keep pumping.

At Able UK’s Seaton Port facilities, on Teesside, work is nearly complete on a £20m project to strengthen 120 metres of quay, ready for the contract the company won to dismantle and recycle the Brent platforms.

Neil Etherington, its development director, said that Able was pursuing a number of North Sea decommissioning opportunities: “In many ways it’s still an emerging market. Even from the mid-1980s people have talked about a Klondyke which will emerge. But it has been relatively slow to develop.”