Cutting Underwater Technologies Develops New Equipment for Frigg Decommissioning Project
01 March 2010
Specialist cutting provider Cutting Underwater Technologies (CUT) has completed a seven figure value project as part of the Frigg cessation project where Total E&PNorge AS is the operator.
The company, a provider to the decommissioning and abandonment industry, carried out work in several phases on the Frigg DP1 & QP platform jackets for Saipem UK as well as the DP2 Jacket and topsides work on the MCP01 for Aker.
The work was carried out over a number of campaigns in 2007, 2008 and 2009 staged to meet the client’s timeline and support vessel availability.
On the final phase of the DP1 jacket dismemberment, CUT used its innovative diamond wire cutting technology to make the 73 separate cuts into the jacket structure. The cuts ranged in size from 24 – 72 inches, and utilised five diamond wire cutting machines with capacities of up to 74in to complete all the cuts.
The work required the construction of custom-built deployment baskets for the 36” and 50” Diamond Wire Cutting Machines (DWCM), adjustable to allow different angles of approach to match the angle applicable to each individual cut.
Extensive trim trials and workclass ROV skid fitment trials were carried out in advance and the bespoke approach ensured additional accessibility and buoyancy which delivered reduced cutting times and costs to the client.
Additionally, for Saipem UK carried out eight cuts as part of the removal of the QP jacket over two mobilisations. Working in some 99m of water CUT carried out the cuts on the Primary Piles (Ø1372mm x 47.3mm w/t) as well as the Insert Pile Ø1067mm x 38mm w/t).
Each cut was completed using a single wire at an average cut time of 3.6 hrs per cut.
CUT UK Sales and Marketing Manager Duncan Griffiths said: “The versatility of our approach is helping our clients develop innovative solutions to their decommissioning strategies that save time and money while minimising environmental impact.
“Our work for Aker MC was unique in that the DP2 jacket was refloated in one section after buoyancy tanks were fitted to the jacket legs to facilitate the installation of the floatation tanks two (2) under-driven piles OD 1376mm w/t 25.4mm which formed an obstruction was severed. Then, once the tanks had been installed, a further 16 cuts to the Corner (OD 1422 mm w/t 70mm) & the Inner (1067 mm w/t 70mm) Piles were completed. A standard 64” DWCM was used to carry out all the cuts”.
In addition to our innovative activity in the North Sea, CUT was subsequently awarded the contract to carry out the cutting associated with the piece-by-piece demolition of the jacket at the Stord Fjord in Norway. This project was carried out by the Groups Norwegian operation “CUT AS” based close to Stavanger at Ålgård.