The steel jacket for the Statoil-operated Mariner field on the UK Continental shelf (UKCS) has now been safely placed on the seabed in the field.
After the sailaway from the Dragados Offshore yard in Cadiz, Spain on August 10, the Mariner jacket spent a week in the Boknafjorden near Stavanger, while waiting for the heavy lift vessel Saipem 7000 to arrive at the field.
According to Statoil, “Skandi Iceman” vessel, towing the S44 barge with the jacket, and the heavy lift vessel were in place in the Mariner field, early on Sunday, August 30. The Mariner field is located around 150 kilometers east of Shetland.
Around 20.25 Sunday night, the jacket was launched from the barge, and early morning on Monday, it was hooked up to the cranes, upended and installed to its permanent location.
Statoil said that the tug “Boulder”, towing the Wagenburg 9 barge with the piles, is expected to arrive on the field Tuesday, September 1.
A total of 24 piles will be driven into the seabed to secure the platform jacket. Each pile is 65 meters long with a weight of 250 to 300 tonnes.
The remaining installation activities are expected to continue for another 10-14 days.
Statoil claims that, with 134 meters high and a footprint of 88 x 62 meters, the Mariner sub structure is the largest steel jacket ever built for a Statoil project. The weight at load-out was 22,400 tonnes including floatation tanks and rigging.
Statoil is the operator of Mariner with 65.11% equity. Co-venturers are JX Nippon Exploration and Production (U.K.) Limited (28.89%) and Dyas UK Ltd. (6%).