ONS 2014: Statoil moves to prove more gas at Aasta Hansteen

Offshore staff

STAVANGER, Norway –Statoil plans to drill three exploration wells during 2014-15 in an attempt to prove more gas for the deepwater Aasta Hansteen field development in the Norwegian Sea.

Project director Torolf Christensen, speaking at ONS on Tuesday, said the project’sspar platform – the world’s largest to date and the first offshore Norway – will also serve for future discoveries in the area, which currently is devoid of offshore infrastructure.

The associated newPolarled gas export pipeline will extend 500 km (311 mi) southeast to the processing complex at Nyhamna that currently handles gas from the Ormen Lange field. Polarled has also been designed with tie-in points for other emerging gasfield developments along the route.

All main engineering for the project has been completed. Christensen said, and construction is starting to pick up pace. Aside from the spar, whichHyundai is building in South Korea, fabrication of other main components is under way, including the living quarters in the Netherlands.

Offshore work started this summer, with Deep Ocean close to completing laying of the subsea fiber optic cable, while rock placement is under way along the seafloor route of the Polarled line.

According to subsea project manager Helge Hagen, the water depth of 1,300 m (4,264 ft) is 50% deeper than for any previous Norwegian platform. The project presents a series of challenges for the subsea facilities, he added, including rough weather, strong currents and waves on this part of the shelf, which is 300 km (186 mi) from the shore, and temperatures on the sea floor of -1.5°C (-29°F).

The spar will be moored by 17 polyestermooring lines and connected to steel catenary risers. Both are firsts for the Norwegian shelf, he pointed out. The mooring lines will be fixed by 20-m (65 ft) high, 145-ton suction anchors built in Norway.

Other new features for a Norwegian project are the three guideline-less templates for the seven subsea gas production wells, and a novel subsea workover system, designed by Aker Solutions. Statoil hopes to re-use the workover system on other projects.

The spar will additionally be used to store Aasta Hansteen’s produced condensate, a first for any spar worldwide.

Statoil has contracted the semisubWest Hercules for the 600-day development drilling campaign.

8/27/14