Spirit Energy has completed a £40 million ($55 million) decommissioning campaign in the UK North Sea, plugging and abandoning three subsea wells and removing more than 234 tonnes of offshore infrastructure.
The campaign, conducted between April and July, included P&A work on the Seven Seas and Grove G5 production wells and the Grove Deep exploration well in the UK Southern North Sea. Spirit worked with more than 30 UK supply chain companies, including DeepOcean and Well-Safe, to execute the program.
DeepOcean deployed the Edda Freya construction support vessel for enabling works at Seven Seas and Grove G5. At Seven Seas, approximately 60 km off the East Yorkshire coast, crews removed a 100-tonne wellhead protection structure.
The vessel subsequently moved to Grove G5, approximately 131 km east of the Norfolk coast, where remotely operated vehicles disconnected subsea infrastructure and prepared the well for further decommissioning work.
Well-Safe’s Well-Safe Protector jackup rig was deployed at Seven Seas and Grove G5 to carry out reservoir abandonment activities. The overall campaign involved more than 114,000 work hours and multiple offshore vessels and ROV systems.
“Some of the biggest challenges involved working with older infrastructure, alongside the Southern North Sea’s notoriously unpredictable weather,” said Ceri Wheaton, Spirit Energy’s decommissioning manager. “We’ve had multiple vessels in the water at any one time, including tugs, a rig, a construction support vessel and ROVs.”
Seven Seas and Grove G5 collectively produced approximately 56 Bcf of natural gas during their operating lives. Grove G5 produced from 2008 to 2019, while Seven Seas operated from 2012 until production ceased in 2024.
Spirit said all 234-plus tonnes of subsea materials recovered during the campaign are expected to be reused or recycled at UK yards.
The project was carried out in line with the North Sea Transition Authority’s Decommissioning Charter, which promotes collaboration between operators and the supply chain to improve the cost and efficiency of UK offshore decommissioning.
source: WorldOil