Spirit Energy has successfully completed a £40 million decommissioning operation in UK waters, combining multiple operations within a single campaign to plug and abandon (P&A) three subsea wells, removing more than 234 tonnes of subsea infrastructure and with 100 per cent of the recovered materials to be reused or recycled in UK yards.
Working alongside more than 30 UK supply chain partners, including DeepOcean and Well-Safe, Spirit Energy safely and successfully delivered key plug and abandonment activities on the Seven Seas and Grove G5 production wells, and the Grove Deep exploration well, located in the UK Southern North Seas between April and July this year.
Highlighting the important role domestic gas has played in UK energy security, the Seven Seas and Grove G5 wells collectively produced 56 billion cubic feet of gas during their operational lives, enough to heat more than 2.5 million homes for a year.
The campaign reflected the collaborative approach and best practices set out in the North Sea Transition Authority's Decommissioning Charter, which Spirit and 16 other UK operators have committed to supporting. This included close engagement with supply chain partners and the efficient deployment of specialist vessels and rig resources.
DeepOcean's construction support vessel, Edda Freya, carried out enabling works at both locations. At Seven Seas, located approximately 60km off the East Yorkshire coast, the team successfully removed the 100-tonne Wellhead Protection Structure. The vessel then mobilised to Grove G5, 131km east of the Norfolk coast, where remotely operated vehicle operations were used to disconnect subsea infrastructure and prepare the well for the next phase of decommissioning.
Well-Safe’s jack-up rig, the Well-Safe Protector was subsequently deployed to both Seven Seas and Grove G5, safely completing reservoir abandonment activities and making significant progress on the wider decommissioning campaign before returning to Aberdeen.
Together, the Seven Seas and Grove G5 wells contributed to UK gas supply between 2008 and 2024, with Grove G5 producing from 2008 to 2019 and Seven Seas from 2012 until ceasing production in 2024.
The campaign was a complex undertaking that involved more than 114,000 hours of work, underlining the importance of collaboration between Spirit and its supply chain partners.
Spirit’s Decommissioning Manager, Ceri Wheaton, said: 'Some of the biggest challenges involved working with older infrastructure, alongside the Southern North Sea’s notoriously unpredictable weather. It’s why close working across all of Spirit’s teams and with our contracting companies has been absolutely critical to this project's success.
'We've had multiple vessels in the water at any one time, including tugs, a rig, a construction support vessel and ROVs, all while having to work together along with existing assets that are still in the field. Frequent and clear communication between onshore and offshore means that decisions can be made quickly leading to a safe and efficient campaign.'
The UK industry is committed to decommissioning subsea wells which are no longer producing oil or gas in a safe, cost-effective and timely manner, while reducing environmental risks and lowering the cost of decommissioning tax relief to the Exchequer.
Matt Browell-Hook, Spirit’s Director of Energy Transition, Decommissioning and Projects added: 'Safely and efficiently decommissioning offshore infrastructure when it cannot be repurposed is a key focus for our industry, and our support for the NSTA’s decommissioning charter reflects our commitment to doing this work safely and efficiently.
'It’s particularly pleasing that we are on course to recycle or reuse 100 per cent of the subsea materials recovered with the work to be carried out in UK yards. The campaign has been a great example of how operators and contracting companies can work together, and its success is testament to the hard work and expertise that exists right across the UK supply chain.'
Background
A video of the combined decommissioning campaign is available here: Seven Seas and Grove decommissioning campaign
Source: Spirit Energy
