Acid-anhydride esters as oil field corrosion inhibitors

Abstract

A corrosion inhibitor with excellent film forming and film persistency characteristics may be produced by first reacting C.sub.18 unsaturated fatty acids with maleic anhydride or fumaric acid to produce the fatty acid Diels-Alder adduct or the fatty acid-ene reaction product. This adduct or reaction product is further reacted in a condensation or hydrolysation reaction with a polyalcohol to form an acid-anhydride ester corrosion inhibitor. The ester may be reacted with amines, metal hydroxides, metal oxides, ammonia, and combinations thereof to neutralize the ester. Surfactants may be added to tailor the inhibitor formulation to meet the specific needs of the user (i.e., the corrosion inhibitor may be formulated to produce an oil-soluble, highly water-dispersible corrosion inhibitor or an oil-dispersible, water-soluble corrosion inhibitor). Suitable carrier solvents may be employed where needed to effectively disperse the corrosion inhibitor formulation.

Dependencies are inferred from the claim text.