Quaternary ammonium salts for corrosion inhibition

A corrosion inhibition formulation comprising:

• a) a bis-quaternary ammonium salt of Formula I
• wherein A is selected from O, NH, C(O), C(NH) or C(S);
• R1 and R2 are independently selected from C1-3 alkyl or H;
• R3 is C1-16 alkyl, C13-20 aralkyl or C2-16 allyl;
• X− is selected from chloro, bromo, iodo, hydroxide, nitrate or sulphate;
• and n and m are independently 1 to 6
• b) alkyldimethylbenzylammonium chloride;
• c) at least one fatty acid methyl ester;
• d) at least one viscosity reducing agent;
• and
• e) at least one solubilizing agent,
• wherein the bis-quaternary ammonium salt of Formula I to the at least one fatty acid methyl ester weight ratio is in a range of 1:3.7-1:5.7.