SAL: MV Svenja, Installing Gas Platform

MV Svenja successfully finalizes her commitment at the KLU Project

Alaska derives its wealth from its crude oil and natural gas deposits, and most of them are located in the Cook Inlet. Exploitation started in early 1960s, but there is still a strong potential for development.

In March 2015 MV Svenja was chartered for the installation of the development platform within the Kitchen Lights Unit #3, a petroleum exploitation area of Deutsche Oel & Gas AG. Covering 337 square kilometers, this is the largest development region in the Cook Inlet.

The development platform consists of three main parts: The Monopod, a 45 m high steel base which, ultimately, will bear the load of the whole construction. It is stabilized by the King Pile, which works as a central pole, driven into the seabed. The other two main parts are the Topside and the Helideck.

For this scope of work MV Svenja required an extensive and technically challenging and time-constrained mobilization in Singapore. Extra living quarters were needed for the 60 supporting team members necessary to complete the project working and living on board for almost five months.

Because of the extremely strong surface sea currents at the installation site, a special mooring arrangement was designed for the vessel which comprised of ten pre-installed anchors strategically located on the seabed. The shipboard component of this arrangement comprised 10 winches and wires which were connected to the pre-laid arrangement. This configuration provided
safe and secure mooring along with precise positioning of the vessel despite the strong tidal currents.

Once the MV Svenja was secured within the mooring pattern, the first job was to drive the King Pile to the required depth. This was achieved with the use of a large hydro hammer. The King Pile not only holds the Monopod securely on the seabed but it also acts as a guide ensuring exact positioning of the Monopod.

With the King Pile in place, the Monopod was transported to MV Svenja by a barge and then lifted onto her deck for additional preparations. Subsequently the two 1000 t cranes of MV Svenja lowered the Monopod, which weighs 1100 t, accurately down to the seabed. Once the Monopod was landed and the cranes freed,
eight additional piles were driven through guides on the Monopod securing it to the seabed.

In early August the Topside, measuring 33 × 30 × 27 metres, was
installed onto the Monopod with a 700 tons single hook lift. “The Topside installation was an extremely tight lift with very small tolerances. It could only be carried out during high tide with an installation window of about four hours”, explained Captain Rüdiger Bauer. “For this reason, careful planning and exact execution was necessary for a successful installation”, he went on. Within two hours including the lift from the barge, the Topside was placed on the Monopod.

This step was followed by the installation of the Helideck measuring 16 × 15 × 6 metres and weighing 40 tons. Although this part of the installation was carried out by a rather simple lift, it still demanded proper planning due to the lifting height and the placement of the center of gravity. The installation went as per schedule. Both SAL and its client Crowley were absolutely satisfied with the course of the installation. “SAL was our primary heavy lift contractor for a highly technical and environmentally challenging installation of an offshore platform over a subsea gas well conductor. SAL’s technical skills, their vessel MV Svenja and the team’s operational experience led to a very successful installation”, states Michael Johnson, Statement Project Manager of Crowley.

Completing the installation of the Helideck and Topside, an essential milestone towards the completion of the infrastructure in the Kitchen Lights Unit #3 has been reached. From end of 2015 on, the first natural gas shall be produced from the Kitchen Lights Unit.

Holger Krenz, responsible Project Manager at SAL Heavy Lift, also expresses his great satisfaction with the project: “SAL is very pleased to have been chosen to undertake the highly technical and complex installation of the offshore platform for our client Crowley. In this project SAL has been able to make excellent use of its specialist knowledge and capabilities to the advantage of our client, Crowley, with the result that a safe and successful project was delivered.”
MV Svenja has returned for demobilization – ready for the
next challenge.