small business home site

Tools for Developing the Russian Arctic Shelf

   First, consider the ice-resistant oil platforms. In earlier article (OGE 04/2011) the author has already mentioned the only ice-resistant production platform currently available for difficult ice conditions – Hibernia platform. To date, of all existing platforms, only the Hibernia can withstand the really difficult ice conditions and icebergs. Ice conditions similar to those in the Okhotsk Sea on Sakhalin-1, Sakhalin-2 and Sakhalin-3 projects, when the ice thickness is below one or even 1.5 meters, can’t be seen as really difficult. In the case of moving ice mass, such ice can be easily broken by gravity bases (the so-called “legs”) of the platform.

   The Hibernia, at the same time, can withstand greater impact of ice mass, including even icebergs. The platform is installed at a depth of 85 meters, its gravity base weighs 450 tons. Four “legs” – four gravity bases of Hibernia – are shackled and protected by the gravitational saw-edged spud can (diameter 106 meters), made of high-tensile prestressed concrete with steel rod reinforcement and prestressed reinforcement elements. External 1.4-meter thick anti-ice wall is star-shaped, with 16 legs used for breaking the coming ice mass. Inner anti-ice wall is 15 meters thick. The platform is designed to withstand the impact of up to 1 million tons iceberg without damage (the probability of meeting such ice mass is estimated as one in 500 years). The platform can withstand up to 6 million tons iceberg, too – but in this case, the platform will sustain repairable damage. The probability of such meeting is estimated as 1 in 10,000 years. Hibernia platform was built in Canada. However, Russian scientists, in particular designers of Rubin design office, also offer ice-resistant offshore platforms, though of somewhat different design. Hibernia is generally cylindrical, with cylinder height 111 meters and diameter 106 meters; the Russian engineers prefer the conical shape. Based on the experience of ancient developers, the pyramid is the most durable form of construction. Russian platforms use wide and heavy gravity base with walls rising at almost 45 degrees to the sea surface; at the top, on the “peak” above the water, there is a lightweight and durable cribrate metal deck that houses the necessary drilling and production equipment.

Source: Oil and Gas Industry Latest News