Corrosion inhibitors for limited oxygen systems

摘要

This invention relates to compositions useful in a limited oxygen system characterized by containing at least one of the following: (1) sulfur-oxygen phosphates (2) quaternaries (3) polyphosphate esters (4) cyclic amidines (5) trithiones. Where the limited oxygen system is aqueous and sour the above compositions (1), (2) and (3) are preferred. Where the limited oxygen system is sour and hydrocarbon/aqueous the above compositions (1), (2) and (4) are preferred. Where the limited oxygen system is sweet and aqueous the above compositions (1) and (3) are preferred. Where the limited oxygen system is sweet and hydrocarbon/aqueous the above compositions (3), (4) and (5) are preferred.