Motion CompensatedPile Drillingin Wikinger
Project Specifications
The Case
The Wikinger offshore wind farm, developed by Iberdrola, is located in the Baltic Sea area, about 34 kilometres away from the island of Rügen. Covering an area of about 50 km², the offshore wind farm was designed to provide 350 Megawatts of electrical power to Germany.
Boskalis was contracted to install the foundations of 70 Wind Turbine Generators (WTGs), each of which consisted of a 4-legged jacket, a transition piece (TP) and 4 piles. Some locations required pile drilling due to presence of large boulders
However, the geographical area of the project limited how Boskalis could execute the work. With soft soil conditions, and an environmentally sensitive seabed, a floating solution was required instead of a Jack up Barge.
Using a floating solution was the most viable option considering environmental limitations but provided its own problems. The swell and waves could jolt the drilling rig when in operation, compromising precision and safety. The sea states limited offshore workability, increasing project downtime and costs.
Our Solution
To combat sea states of up to Hs 1.5m Hs, we proposed the use of our motion compensated platform, the T700. In combination with Boskalis and DDC, we developed a modular solution consisting of the T700 affixed to a standard barge, with both the drilling rig and a crawler crane placed on top of the platform. The solution was mobilised within 2 weeks.
By using the T700 to compensate the heave, roll and pitch (all vertical motions) of the barge, the drilling operations could continue throughout the winter irrespective of waves and swell. The 70mT weighing drill bit was precisely lowered and positioned by the motion compensated crawler crane, eliminating the swing of the drill and drill pipe.
This solution was a world first, with Barge Master providing a novel answer for subsea drilling from a floating barge: an achievement only made possible with the T700. This modular drilling solution worked non-stop, 24/7, and successfully bored the piles for a number of WTG locations. Barge Master’s T700 ensured a steady platform, enabling secure drilling from a floating vessel in challenging offshore conditions.
