Aasta Hansteen, the world’s largest spar platform began its voyage on 21st of April 2017, to make its way from South Korea to the Norwegian Sea. Statoil, the Norwegian oil and gas giant, is behind the enormous transportation project.
The Luva gas field, situated 300 km off the shore in the Vøring area of the Norwegian Sea at a depth of 1,300 meters, was first discovered in 1997. The field was later renamed after a Norwegian women’s rights campaigner Aasta Hansteen in March 2012. The nearest established infrastructure to the oil field being miles away makes it difficult to retrieve oil and gas from the area. The harsh weather conditions of the deep waters are another massive challenge.
The Luva gas field combined with the Haklang and Snefrid Sør is collectively known as Aasta Hansteen now. Estimates show that 47 billion standard cubic meters of gas can be extracted from the field in total. The gas available in the field is dry with low carbon dioxide content. The Snefrid Sør alone offers 31-57 million barrels of recoverable oil according to the company’s estimates.
Statoil got approval for its plans for development and operations (PDO) by the Ministry of Petroleum and Energy in 2013. The spar platform suggested in the PDO is the first gas infrastructure installation of its kind in all of the Norwegian continental shelf. The platform weighs a massive 70,000 tons making it the largest spar platform in the world.
Hyundai Heavy Industries (HHI), South Korea manufactured a substructure of the platform measuring 200 x 50 meters in diameter weighing 46,000 tons. According to the HHI description, the spar platform is “a cylindrical, partially submerged offshore drilling and production platform that is engineered for deepwater operations.” Below is a picture of the gigantic substructure that also has a provision for storage of the condensate, which will be loaded into the shuttle tankers on the field.
Boskalis’ heavy transport vessel called Dockwise Vanguard will float the substructure transporting it to Norway on a two-month journey of 14,500 nautical miles. A few months later, the 25,000-ton topsides will also reach Norway to combine with the substructure. Once the structure is assembled, it will be towed to the Norwegian Sea, 1,300 meters deep into the Aasta Hansteen field. It will the first time Norway uses steel catenary risers (SCRs) and the first to use synthetic rope mooring spread offshore. The country will be the first Scandinavian country to install the mechanically lined pipe using reel-lay.
According to the plans, gas production was due to begin by the third quarter of 2017 which got postponed to 2018 due to the delay in construction of the platform.
Watch the 46,000 tons structure float away in the world’s largest transport vessel: