According to Statoil, construction of the large platform sub-structure started in October 2013 and was completed in May this year, on time and within budget.
It is the largest steel jacket ever built for a Statoil project measuring 134 metres in height and with a footprint of 88 x 62 metres. The weight is 22,400 tonnes including floatation tanks and rigging.
The load-out from the Dragados yard in Cadiz onto the S44 barge took place in late July. Yesterday, the main tug “Skandi Iceman” was connected to the barge and in the afternoon the jacket entered the channel of Bahia Cadiz. Statoil said that the 1 835-nautical mile journey from the southern part of Spain to the Mariner field in the North Sea is expected to take around two weeks.
After it has arrived at the field, the jacket will be launched by the barge being ballasted to a certain angle, enabling the 22,400-tonne structure to slide horizontally into the sea. Subsequently, the structure will be upended and maneuvered into the right position by the heavy-lift vessel Saipem 7000. Finally the jacket will be secured by 24 piles.
Statoil added that topsides installation is planned to take place in 2016.
Norwegian oil and gas giant Statoil is the operator of the Mariner field which lies at water depths ranging between 97m and 112m. It is located approximately 130km off the British coast and 40km northwest from the UK / Norway international boundary.
It is scheduled to be produced with the help of 50 wells and 92 sidetracks that will all be tied-back to a production, drilling and quarters (PDQ) unit secured on a fixed steel jacket platform. The PDQ unit in turn will be tied-back to a floating storage and offloading unit (FPU). The platform will first separate gas and water from the produced oil. The stabilized oil will then be piped to the FSU vessel for storage. From there, it will be shipped to the shore through shuttle tankers.