Ice islands and method for forming same
AssigneeUnion Oil Company of California
InventorFrederick C. Duthweiler
Life of this patent
Estimating the term…
Abstract
An ice island for use in offshore operations in cold waters includes an operations pad and a surrounding containment barrier, the bases of which are grounded on the marine bottom. The island is constructed by accumulating ice in confined areas defined on a sheet of native ice until the mass of the accumulated ice causes the ice underlying and adjacent to the confined area to be depressed with respect to the main body of ice and be grounded on the marine bottom.
Claims12
An ice island for conducting offshore operations in a frigid environment, said ice island comprising:
- an ice mass defining an operations pad, the base thereof being supported on the marine bottom at a desired operations site;
- an ice structure defining a containment barrier surrounding said operations pad and spaced outwardly therefrom, the base of said containment barrier being also supported on the marine bottom;
- a layer of ice disposed in the space between said operations pad and said containment barrier, the undersurface of said layer of ice being spaced above the marine bottom and being unsupported thereby and upper and lower containment basins defined by the upper and under surfaces of said layer of ice and said containment barrier.
An ice island for conducting offshore operations in a frigid environment, said ice island comprising:
- an ice body defining an operations pad having its base grounded on the marine bottom and its upper surface elevated above the level of surrounding native ice to define a raised operations support surface;
- an ice body defining a containment barrier surrounding said operations pad and spaced outwardly therefrom, the base of said containment barrier being grounded on the marine bottom and its upper surface elevated above the level of surrounding native ice, a portion of the periphery of said containment barrier being enlarged to define a relief operations support pad;
- a layer of ice disposed in the space between said operations pad and said containment barrier, the under surface thereof being unsupported by said marine bottom;
- and
- upper and lower containment basins defined by the upper and under surfaces of said layer of ice and said containment barrier.
A method for the construction of a grounded ice island at a frigid offshore location in waters covered by a sheet of floating native ice, said ice island including a central operations pad and a surrounding containment barrier spaced outwardly therefrom, the method comprising:
- forming on the surface of said native ice a first confined area corresponding in shape and size to said operations pad base and forming a second confined area corresponding in shape and size to the base of said containment barrier, and the total area of said confined areas being less than the total area of said native ice overlying said location;
- accumulating ice within each of said confined areas, to form therein ice bodies of sufficient mass to cause said ice in each of said confined areas to settle to the marine bottom and to be supported thereon;
- the area confined within the base of said containment barrier and the undersurface of said native ice defining an upper containment basin;
- continuing said accumulation of ice to build the upper surface of said operations pad and said containment barrier above the surface of said native ice thereby to define an upper containment basin.
Dependencies are inferred from the claim text.