General – Decommissioning
DNO ASA, the Norwegian oil and gas operator, reported that the wellhead platform production facilities have been removed from the Schooner field offshore UK, the last major offshore operation under DNO’s multi-year North Sea decommissioning program.
The heavy lift was conducted using the Heerema Marine Contractors’ Thialf semi-submersible crane vessel. The 1,200-tonne platform deck was lifted aboard the vessel on 17 May, while the jacket was removed on 23 May after the piles had been cut three meters below the seabed.
The deck and jacket have since been transported to the Hoondert Yard in the Netherlands for dismantlement and recycling.
“We have conducted these operations in a safe, cost-efficient and environmentally responsible manner, coordinating five tier-one contractors and displaying our capabilities as a full life-cycle offshore operator,” said DNO’s Chief Operating Officer Chris Spencer.
In 2019, DNO assumed operatorship and working interest in the Schooner and Ketch fields in the UK and the Oselvar subsea field in Norway, three end-of-life fields whose decommissioning had been deferred by the previous operator.
DNO completed plugging and abandonment (P&A) of the nine Ketch wells and the three Oselvar wells in 2021, followed by the 12 Schooner wells in 2022.
The Ketch and Oselvar production facilities were removed and dismantled last year. It is expected that about 95 percent of the removed materials will be recycled.