Russia’s first offshore concrete gravity platform begins journey to Sakhalin
Posted: 15 June 2005
The concrete gravity base substructure (CGBS) for the Sakhalin II Phase 2 Project’s Lunskoye A platform began its epic journey to Sakhalin, when it was towed out of the dry dock in Nakhodka near Vladivostok, Sakhalin Energy reported.
The first of its kind to be built in Russia, the concrete platform will now be towed by three ocean going tugs to the installation site on the Lunskoye Field, offshore north east Sakhalin. The journey is expected to take some 16 days, subject to weather, and will cover a distance of 1765 kilometres.
The Lunskoye CGBS and its sister CGBS for the new Piltun Astokhskoye offshore platform (PA-B), which will be installed on the Piltun feature of the PA field later this year, are amongst the largest concrete structures ever built in Russia. The construction of the structures required a workforce of some 2,000 Russian nationals, and involved extensive use Russian industry, labour and materials.
Sakhalin Energy Deputy Chief Executive Officer and Project Director David Greer said: “The unique shape and complex geometry of the Lunskoye-A and Piltun-B concrete structures and the need for them to withstand the harsh climate and ice conditions offshore Sakhalin places them amongst the most complex concrete construction projects ever undertaken anywhere in the world.
“It is a pioneering achievement for Russia and a great tribute to all the men and women who helped design and build them in record time. Their effort and contribution towards the success of the Phase 2 Project will never be forgotten.”
Norwegian design and engineering experts, Aker Kvaerner - who have unparalleled experience in such concrete structures - and Finnish construction experts Quattro Gemini, worked with more than 250 Russian companies and suppliers to complete the structures. Russian companies from Nakhodka, Primorsky Krai and other parts of Russia - including Amurmetal, Komplex, Astrakhan Korabel, Dalgidrostroy, Daltekhflot, Massis, NSRZ and Zvezda - played a major part in the construction work and supply of materials for the CGBS.
Some 6 million Russian manhours, and 97 percent of the materials were purchased in Russia. Russian nationals accounted for more than 92 percent of the construction workforce of engineers, workers and other staff.
The Lunskoye CGBS consists of a caisson base and four cylindrical (truncated cones topped by cylinders) legs that support the topsides of the new offshore platform. It has a total weight of 103,000 tonnes. The base is 105 metres by 88 metres and 13.5 metres high. The diameter of each leg measures more than 20 metres at the base and they are some 56 metres high. Total height of the entire structure is 69.5 metres.
The Lunskoye CGBS will be located 15 kilometres off the north-eastern coast of Sakhalin Island, in a water depth of 48 metres. The platform will support drilling facilities, accommodation and minimum processing facilities. It will have the capacity to produce 51 million cubic meters of gas per day (1,800 million standard cubic feet per day), and approximately 50,000 barrels of condensate per day (8,000 cubic meters per day).
Separation, including treatment and separation of the Lunskoye gas and condensate will be undertaken onshore at an Onshore Processing Facility, which will also supply power to the platform via submarine cable.
The Lunskoye platform will produce the majority of the gas for Sakhalin Energy’s LNG plant, which is currently under construction on schedule in the south of island.
For more information see www.sakhalinenergy.com