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Once the pipelay equipment was on board, the vessel sailed to the Gulf of Mexico for some trials then started straight away on the Lucius project. It

Subsea emerged during the trials that the weight of the reel and the exact height of the crane resulted in a pendulum effect.

The natural frequency of the pendulum exactly matched the vessel’s response to

Aegir’s ? rst project the long swell. The solution was a damp- ened tugger system. This gave a change

Heerema Marine Contractor’s in damping according to the velocity of new multi-purpose construction the pendulum. Interestingly, “not only did it damp the motion of the reel, but it vessel completed its ? rst Aegir also damped out the whole system, so the job in the Gulf of Mexico. Meg vessel stopped rolling as well.”

The Lucius project comprised the sub-

Chesshyre reports.

sea tieback of six wells in a water depth of 7100ft. The Aegir’s scope of work he ? rst mobilization for Heerema consisted of four 8in., three 6in. ? ow-

Marine Contractor’s newbuild lines, six 8in. SCRs (steel catenary risers),

T multi-purpose deepwater con- a 140-tonne manifold and a crossing struction vessel Aegir was for the subsea mattress. Heerema’s DCV Balder installed part of Anadarko’s Lucius Spar project in the suction piles, the SPAR mooring and the Gulf of Mexico, which was completed another manifold, and the DCV Thialf 4000 mt mast crane early in 2014. installed the topsides.

2000 mt

RJ-lay tower

The job was awarded before the vessel The pipelay required the use of four

Aegir - main equipmentAegir - main equipmentAegir - main equipmentAegir - main equipmentAegir - main equipmentAegir - main equipment was even built, as Meredith Taylor, senior reels. The heaviest one weighed 2754-

Length o.a. 211.5m project engineer with Heerema Marine tonne in total, including the reel and 3000 mt

Width 46.2m

Contractors (HMC), based in Houston, rigging. The pipe weight was 1646-tonne. 800 mt lifted reels

Depth 16.1m tensioners explained at the International Marine The weather was good, with a signi? cant

Draft(working) 9–11m

Contractors Association’s recent annual wave height of only 1.4m for the ? rst reel

Draft(transit) 8 m seminar in London. for a short period, the other sea states

Installedpower 48MW

The decision to build a new vessel was being lower. This meant it wasn’t pos-

Dynamicpositioning DP3 taken because Heerema, as a key player sible to test the system to its limits.

Transitspeed 12 knots 1500 mt in complex deepwater construction for Computational ? uid dynamics analysis

DWL system

Accommodation 289 POB over 10 years, wanted to maintain and was used to model hydrodynamic loads. expand its position in the expected A radar wave measurement system in the wanted to make the new vessel, named plus lifted reels and the use of a pipelay growth of the market in complex high- moonpool allowed for the monitoring of after a Norse god of the sea who ruled the abandon or recover system for deepwater tech ? eld developments. the waves compared with those outside. waves, back to back compatible with its lowering. The pipelay tower is called an A mix of high-end capabilities were Steering winches added as a result of the existing deepwater construction vessel R J tower by HMC, because it can perform chosen for the new vessel, including analysis gave extra control and damped the Balder. A monohull was selected reel-lay and J-lay, by using different ways heavy pipelay to 2000-tonne top ten- out some of the pipeline end termination for good transit speed (12 knots) for to hold the pipe – friction clamps and sion and 3500-mwd, heavy lifting to movements during the lowering.

worldwide operations and good work- hang off collars. 4000-tonne capacity using a mast crane, The moonpool was also used to lower ability in the long swells found offshore The lifted reels concept meant that the heavy reeling to 800-tonne top tension, the 140-tonne manifold down to 6820ft

West Africa and Brazil. It was based on vessel could stay using the deepwater lowering system, an existing vessel design, a customized on the ? eld with having been handed over from the crane 2 reels + 1 reel drive unit

Lifted reels concept on vessel

Ulstein Sea of Solutions SOC 5000, to the reels being using a 45m synthetic sling. The system empty reel speed up the payback time. brought from shore. was designed to operate in up to 3m sea in transit “We decided to build the Aegir in The width of the states, but once again the weather was 2010,” Taylor says. “We were negotiat- vessel (46.2m) perfect. “It was like a millpond when we ing the (Anadarko Lucius) contract in meant that it was installed it,” Taylor says. 1 reel + 1 reel drive unit 2011. At the start of 2012 the contract possible to put In mid-October 2014, the Aegir started at quay was awarded just after we had laid the three reels across at on a contract transporting and install- keel, so we were having to do analysis a time. ing in? eld ? owlines, subsea structures full reel and design procedures based on equip- HMC also and moorings for the INPEX’s Ichthys in transit

Tie-in ment that hadn’t yet been fabricated or LNG project, on a sub-contract from station

Pipe installed. We had to set up the offshore McDermott Australia. HMC also has a production ramp spooling yard before the vessel had contract for the Aegir for the installation

Pipe stalks, length suited

Images from arrived in Rotterdam (for installation of of the Shell Malikai tension leg platform to continuous operation

Heerema Marine the pipelay equipment by Huisman).” in Malaysia.

Contractors.

February 2015 | OE oedigital.com 56 056_OE0215_Subsea1_Aegir.indd 56 1/20/15 6:39 PM