Client: Heerema Fabrication Group
Location: Dutch sector North Sea F3-FA field
Year executed: 2010
Centrica has chosen the SIP-2 concept for an expected short field life of 7 years, after which the platform will be relocated to another offshore site. SPT Offshore managed to meet a 18 months EPCI schedule and the offshore installation took only 52 hours with a minimum offshore spread consisting of a cargo barge, towing tugs and an OCV.
The F3-FA gas field is located approximately 240 km north of Den Helder, at a waterdepth of approximately 40m, within the Dutch sector of the North Sea. The marginal field is operated by Centrica, which holds a 58% working interest in the field.
The gas field was discovered by Nederlandse Aardolie Maatschappij (NAM) in May 1971, with the drilling of the F3-01 well. The field was first appraised by the B18-3 well in February 1982 and further appraised by the F3-08 well in March that same year. Venture Production took over the ownership of the field from NAM in March 2008, and initiated the front end engineering and design (FEED) study for the development of the field from April to August 2008, incorporating STP Offshore’s proprietary SIP2 concept. Centrica took over the operatorship of the field from Venture Production in August 2009 and continued the development.
The development plan for the Dutch North Sea field, incorporating a self-installing platform (SIP), was approved in the second half of 2008 and construction works started in April 2009. The first development well, the F3-FA-01 single high-angle well, was drilled in October 2010 using the Noble Scott Marks drilling rig and the field came into production in January 2011.
Centrica’s F3-FA SIP, the largest platform of its kind, is designed to operate for around 20 years. It is built to comply with the strict regulations imposed for operations in the Dutch and UK sections of the North Sea. The platform will be transferred to other prospects when production halts from the current field. The SIP is provided with facilities for sepraration of gas, condensate and water, and compressing the gas before being exported onshore. It has capacity to treat three million cubic metres of gas per day, 400m³ of condensate and up to 150m³ of water.
The platform’s topside is composed of a cellar deck, a main deck and a top deck. It further features four sub-decks, including a mezzanine deck, an intermediate deck, a heli-deck and a weather deck. The platform provides accommodation facilities for 18 people on the main and intermediate decks.
F3-FA platform specifications and installation
Centrica’s F3-FA SIP’s topside weighs 4,000t and is 30m-long, 50m-wide and 30m-high. Each of the platform’s suction piles is 13m-long, has a diameter of 15m and weighs 400t. The platform’s legs are 75m-long, have a diameter of 3.5m and weigh 375t each. The stiffening frames weigh 425t each, while the overall weight of the platform is 9,500t.
The platform was installed employing the Boa 35 transportation barge, three tugs and a diving support vessel (DSV). Installation works were completed in September 2010.