The steel jacket for the Statoil operated Mariner A platform on the UK Continental Shelf (UKCS) left the Spanish Dragados yard yesterday (August 10) and is now on its way to the North Sea.
Construction of the large platform sub-structure started in October 2013 and was completed in May this year, on time and within budget and with a very good HSE performance. 134 metres high and with a footprint of 88 x 62 metres, it is the largest steel jacket ever built for a Statoil project. 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 safely entered the channel of Bahia Cadiz. 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, ensuring that it is safely fixed for many decades to come.
Topsides installation is planned to take place in 2016.
Facts:
- The Mariner Field is located on the East Shetland Platform of the UK North Sea, approximately 150 kilometres east of the Shetland Isles.
- 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%).
- The Mariner heavy oil field consists of two shallow reservoir sections – the deeper, Maureen Formation at 1492 metres and the shallower Heimdal reservoir at 1227 metres.
- The development of the Mariner field will contribute more than 250 million barrels reserves with average plateau production of around 55,000 barrels per day.
- The field will provide a long-term cash-flow over a 30-year field life. Production is expected to commence in 2017.
- The concept chosen includes a production, drilling and quarters (PDQ) platform based on a steel jacket, with a floating storage unit (FSU).
- Drilling will be carried out from the PDQ drilling rig, with a jack-up rig assisting for the initial years.