US Patent 7906461 Thermally stable compositions and use thereof in drilling fluids

A composition is comprised of a mixture of the reaction product of an amine and a poly-functional isocyanate, and the reaction product of (i) a carboxylic acid with at least two carboxylic moieties; (ii) a polyamine having an amine functionality of two or more; and a chemical selected from the group consisting of (i) alkoxylated alkyl amines, (ii) fatty acid amides and (iii) mixtures thereof, and it is used as a drilling fluid additive.