Fossil Energy – Decommissioning
Australian-based Shelf Subsea has been contracted by the Ministry of Business, Innovation and Employment (MBIE) to carry out the latest stage of the three-phase campaign, which involves removing all the subsea equipment at the field.
Purpose built diving support vessel Southern Star arrived at Port Taranaki last week for an initial four-day visit, where it unloaded and tested emergency hyperbaric equipment, and took on diving personnel, project staff and supplies.
As it did in phase one of the decommissioning – the demobilisation of the floating production, storage and offloading vessel Umuroa – Port Taranaki will be the on-land base for the approximate two-month campaign.
During the project, Southern Star will make about five visits to port to offload and store the retrieved subsea equipment, and for resupply and crew changes. Throughout, Port Taranaki will provide berthing and pilot services, laydown areas, and general wharf services, including the use of cranes, forklifts and other specialist equipment if needed.
Shelf Subsea project manager Jack Forbes said about 40km of flow lines and 3500 tonnes of steel from subsea manifolds and mid-water arches would be prepared for recovery by underwater remotely operated vehicle (ROV) at the field and brought to Port Taranaki, where it would be unloaded and stored before being removed.
He said the initial work at the field, beginning this week, would be carried out by a 15-strong team of specialist deep-sea divers. They are to spend two weeks preparing the infrastructure at the sea bed, including checking connection points for the ROV before the retrieval work begins.
“The divers, who are all from New Zealand, will be going down about 120 metres to the sea floor for the preparatory work, and will then support some of the recovery work going forward.”
Port Taranaki head of commercial Ross Dingle said the port was pleased to be continuing its support