ICE-RESISTANT OFFSHORE PLATFORM AND METHOD OF ITS OPERATION Russian patent published in 2004 - IPC

FIELD: building of offshore platforms for boring and/or production of oil or gas in deep-sea regions with ice periods. SUBSTANCE: proposed ice-resistant offshore platform has bearing base made in form of floating column with buoyancy compartments and maneuverability ballast tanks; its lower portion is not watertight and is used for solid ballast. Offshore platform is anchored by means of system of inclined anchor couplings located in star-shaped pattern, for example. Floating column is provided with additional system of sagging heavy chains secured by eye rings found in lower portion of platform; at other end, chains are secured to piles in sea bottom; length of chains exceeds maximum permissible distance of eye rings from sea bottom. Method of operation of offshore platform includes positioning of ice-resistant platform, regulation of tension of anchor couplings in accordance with preset draft and keeping the floating column in vertical position. In case of rise of sea level, water ballast is received into maneuverability tanks which is removed when sea level drops. Measures are taken to minimize inclination of floating column. Draft of ice- resistant platform and tension of anchor couplings are changed depending on weather conditions; in case of ice conditions, draft is decreased and excessive buoyancy and tension of anchor couplings are increased. To this end, water ballast is removed from maneuverability tanks and draft is increased; under storm conditions and excessive buoyancy and tension of anchor couplings are decreased by admitting water ballast into maneuverability tanks. EFFECT: optimal conditions for oil production in case of sea swell. 5 cl, 3 dwg