Hull heating system for an arctic offshore production structure

Claim 1

An offshore production structure for use in a body of water that contains ice masses, comprising: a support portion positioned in a body of water, said support portion having a peripheral wall which converges upwardly and inwardly of the underwater bottom to provide a ramp-like surface to receive ice masses moving relative to and into contact with said support portion so as to elevate the ice above its natural level an amount to cause the ice to fail in flexure adjacent said structure; means securing said support portion to the underwater bottom; a production well being produced from said structure; means for applying the heat from produced fluids from said well to the inner surface of said peripheral wall to maintain the temperature of the outer surface of said peripheral wall above the melting point of ice in contact with said structure to prevent the ice from freezing on and adhering to said peripheral wall so as to assist the ice in moving over said peripheral wall, wherein said means includes at least one chamber disposed within said support portion with said peripheral wall forming the outer wall of said chamber; and means for circulating a heat transfer fluid through said chamber wherein said heat transfer fluid is heated by said produced fluids in an amount to maintain the outer surface of said peripheral wall above the melting point of the ice.