As it continues to build up its natural gas infrastructure in the North Sea, Statoil has chosen SmartPlug® isolation technology, by T.D. Williamson (TDW), to safely isolate a 150 km wet gas pipeline from its Huldra platform to the Heimdal Gas Center.

To this end the company has elected to lay a 27 km pipeline from Valmont and tie into the existing Huldra-Heimdal pipeline.

The tie-in alternative necessitated a fairly complicated isolation operation, for which Statoil turned to TDW. The SmartPlug isolation method provides a proven, double block and monitor isolation that would prevent flooding during the tie-in operation.

“The DNV GL-certified SmartPlug isolation method allowed production from Huldra to continue for an additional five months,” says Atle Halvorsen, TDW Project Manager. The line was isolated for 89 days at an average isolation pressure of 84 bar and hydrotested at 174 bar.