METHOD FOR CONSTRUCTING ARCTIC PLATFORM Russian patent published in 2004 - IPC

FIELD: technology for extracting underwater deposits of mineral resources.

SUBSTANCE: method includes mounting of base onto previously prepared soil, on soil a half-immersed horizontal platform is mounted with technological equipment. Base is composed of two parts, lower part of base is connected to soil by means of cemented piles, upper portion of base half-immersed horizontal platform is provided with pontoons with ballast tanks. In operating position upper portion of base is connected to lower portion and to half-immersed horizontal platform by means of respective fixing connections. Lower portion of base is also provided with ballast tanks. Upper portion of base is mad with central shaft for mounting technological communications. Transporting and mounting of platform onto bottom is performed consecutively or in previously assembled state with use of said ballast tanks. Lower portion of base is fixed to soil with tension piles, and height of lower portion of platform base is selected considering condition of possible passing of icebergs of sizes common for current region. In separate cases before installing of platform to bottom its positioning is performed by means of technological anchor system. Then ballast tanks are loaded to provide for soft lessening of platform buoyancy as a whole and given tension of elements of technological anchor system with use of respective drives until platform is set on soil. In case of necessity after mounting of platform onto soil its ballasting is performed. Then special wells are drilled with consideration of necessary passing of non-stable rocks, casing pipes are mounted, and after that lower portion of sea platform base is rigidly connected to soil by a system of tension piles, anchors of which are set at given depth inside casing pipes in area of stable rocks of soil and their tension is performed and loads are evened by tension mechanisms and respective hydraulic system. In case of approaching iceberg or massive ice cover fixing elements are disengaged, which connect upper and lower portions of base to each other, while providing for needed pressurization of technological communications. Half-immersed horizontal platform and upper portion of base is at same time or consecutively floated aside from iceberg trajectory. After finish of operation of arctic platform pressurization of technological wells is performed, anchors of tension piles are disengaged from casing pipes, tension piles are removed. Half-immersed horizontal platform, upper portion of platform base, and lower portion of base, is at same time or consecutively raised and transported with use of ballast tanks.

EFFECT: higher efficiency and operation safety.

5 cl, 2 dwg