Castorone lays first North Sea Sverdrup pipes

Saipem’s Castorone vessel has started laying the oil export pipeline for the Johan Sverdrup project in the Norwegian North Sea.

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Offshore staff

STAVANGER, Norway – Saipem’s Castorone vessel has started laying the oil export pipeline for the Johan Sverdrup project in the Norwegian North Sea.

Operations started last week close to the Mongstad oil terminal, north of Bergen.

The 36-in. oil pipeline will be Norway’s largest and longest to date, claimed operator Statoil, extending more than 280 km (174 mi) out to the Johan Sverdrup field and in a maximum depth of 537 m (1,762 ft) below the sea surface.

The near-shore section is being pulled through a pre-drilled hole at the bottom of the Fensfjord into the oil terminal. When the field eventually produces at peak in the 2020s, up to 600,000 b/d will flow into Mongstad.

Assuming all goes as planned, the oil pipeline should reach the field center in July. TheCastorone will also install the 18-in. gas export pipeline system.

Costs for Phase 1 of the development have fallen by more than NOK35 billion ($4.39 billion) once the original plan gained approval. Of this, NOK1.2 billion ($150 million) came from re-routing the pipeline through the Fensfjord.

The original idea had been to route the line onshore 10 km (6.2 mi) from the oil terminal, but at the time it did not appear to be technically feasible to lay the pipe through the Fensfjord due to the presence of other pipelines in the area and possible subsurface instability.

However, a study in 2015 showed that a subsea pipeline route was possible as long as infill support for existing pipelines was in place. These conditions have been put in place.

04/30/2018

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