The jacket structure for the platform at Statoil's Mariner-field in the UK sector of the North Sea was safely transferred to the towing barge at the yard in Cadiz at the southern coast of Spain on the 25th of July. The operation is documented on a timelapse video.
NGI was in the project from the start, performing geotechnical FEED for the pile and mudmat design, for SNC Lavalin. In addition NGI did perform the reliability study during detailed design for SNC Lavalin and in connection with verification work for Dragados. This analysis resulted in significantly shorter piles. This is documented in OTC-paper 24063 and ISFOG 2015 paper "Approach for the calibration of the load and resistance factors for axial pile capacity calculations".
The timelapse video, taken by Dragados Offshore, shows the Mariner jacket being loaded onto a barge off Spain's Cadiz coast. The jacket, equipped with buoyancy and rigging tanks, weighs 22,400 tons. Without the tanks, the structure weighs in at 19,300 tons, making it the Norwegian operator's largest jacket on record. It stretches 150 metres covering an area of 88m by 52m on the seabed - an area larger than Aberdeen Football Club's pitch. The barge will travel 1,845 nautical miles to the Mariner field in August. The trip is expected to take 15 days. It is due to be installed in September.
Statoil's Mariner project is the largest field development on the UKCS in more than a decade, with a gross investment of more than $7billion. It is expected to produce more than 250 million barrels of heavy oil during its 30-year lifespan, with average plateau production hitting around 55,000 barrels per day.