A SUCCESSFUL COMPLETION TO THE DECOMMISSIONING OF NINIAN NORTH PLATFORM
The Ninian North Platform was the most northerly of the three installations of the Ninian Field located in Block 3/3 of the East Shetland Basin approximately 130 nautical miles northeast of the Shetland Islands. The platform was installed in 1978 in a water depth of 141m. Originally a combined drilling, production and accommodation platform with a capacity for 150 persons on board, it was supported by an 8-legged steel jacket.
In April 2022 Waves Group were offshore providing marine warranty services for the removal of the 8000t NNP jacket with a surveyor onboard Allseas heavy lift vessel Pioneering Spirit for the offshore lift, tilt, and transportation back to the decommissioning yard in the Shetlands. The removal campaign marked the first time that the recently commissioned jacket lift system (JLS) beams had been used to remove a jacket. The successful lift followed a jacket member cutting campaign assisted by the construction support vessel Oceanic for which Waves Group also had a surveyor onboard to monitor the work.
On leaving the field, the Pioneering Spirit headed for the decommissioning yard situated at Dales Voe in the Shetland Islands where preparations began for the transfer of the jacket to the Iron Lady cargo barge. This included derigging of the jacket trunnions and setting up the skidding system to facilitate the transfer from the JLS beams to the barge skid beams. Water depth restrictions at the quayside for the Pioneering Spirit meant that the inshore transfer onto the barge was necessary. After transfer, the barge was then moored to the quayside and the jacket loaded-in onto the quayside skid track and set down on the quay supports ready for demolition and recycling.
For Waves Group, this was the culmination of a project that was awarded back in 2017 and entailed several phases with offshore campaigns for topsides bearing block installation, separation of topsides from the jacket, topsides removal, offshore welding of jacket lift points, and ending with the final jacket member cutting and removal lift in April.
