Patent ID: 7060129

Claim:
A cement composition comprising: (a) a cement; (b) a gelling additive capable of passing into a subterranean zone when the cement composition is displaced into a well bore, the gelling additive being further capable of fanning a crosslinked gel in the subterranean zone to inhibit gas migration from the subterranean zone into the cement; and (c) an organic gelling agent capable of crosslinking the gelling additive wherein the gelling agent is selected from the group consisting of a polyalkyleneimine, a polyfunctional aliphatic amine, an aralkylamine, a heteroaralkylamine, and combinations thereof, and wherein the gelling additive is a copolymer of at least one non-acidic ethylenically unsaturated polar monomer and at least one ethylenically unsaturated ester.