Courtesy of teknoblog.ru

SAL Heavy Lift’s team of MV Svenja has successfully installed an offshore development platform over a subsea gas well conductor in the “Kitchen Lights Unit # 3” area in Alaska's Cook Inlet.

The company says that, “Kitchen Lights Unit # 3” is exposed to a tidal range of 25 ft which provokes currents in excess of 5 knots. It is the largest exploitation area in Alaska’s Cook Inlet – surrounded by active volcanoes and extremely strong tidal currents.

In March 2015 MV Svenja was chartered for the installation of the offshore development platform within the petroleum and gas exploitation area operated by Deutsche Oil & Gas AG on 337 sq km. The area posed major technical and operational challenges for SAL Heavy Lift within the installation.

Holger Krenz, responsible Project Manager at SAL, said, “15 specialists of SAL planned the construction and installation of the platform, designed a special mooring arrangement for the vessel, drafted the temporary living quarters onboard the MV Svenja and accompanied the project steps in detail – from scheduling over cost-controlling to vessel stability calculations, rigging design and lifting procedures. 25 SAL colleagues and a team of 58 experts from Crowley and sub-contractors did rely on the most accurate preparations for the later installation onboard the vessel.”

After mobilization in Singapore MV Svenja set off to Alaska. Precisely moored, the installation crew first had to drive the King Pile into the seabed - close to the wellhead, a connection piece standing out four meters out of the ground in a water depth of more than 30 m. The King Pile worked as a guide to lower the Monopod safely onto the wellhead. A high precision operation with an 80 tons heavy hydro hammer.

The crew had to “thread” the Monopod, a 45 m high steel base, exactly over the wellhead – without underwater visibility and by a complex lifting arrangement. Once the Monopod reached under the waterline the crane commander lost visibility of the unit. So the crew had to fully rely on a subsea 3-D-sonar-system, displayed on separate monitors in a special survey container. The crew completed the platform installation by installing the 40 tons Helideck.

At the end of August, after 90 days on-site, the whole installation was completed and MV Svenja headed back to Singapore for two weeks of demobilization.

Source: worldoil.com