The present disclosure relates to a corrosion inhibitor formulation comprising: a) at least one quaternary ammonium salt; b) at least one fatty acid methyl ester; c) at least one viscosity reducing agent; and d) at least one solubilizing agent, wherein the at least one quaternary ammonium salt to the at least one fatty acid methyl ester weight ratio is in the range of 1:0.2-1:5.0. The instant disclosure further relates to the process of preparation of the corrosion inhibitor formulation.

Corrosion inhibitor compositions and methods for inhibiting corrosion on a metal surface exposed to a hydrocarbon fluid are provided. The corrosion inhibition compositions can include a corrosion inhibitor, such as 3-dimethylamino benzoic acid, 4-dimethylamino benzoic acid, or 2,5-dihydroxyterephthalic acid. The corrosion inhibitor composition can further comprise dimethyl sulfoxide, and heavy aromatic naphtha. The corrosion inhibitor composition can be phosphate-free and can inhibit naphthenic acid corrosion. In the methods, a corrosion inhibitor composition is added to the hydrocarbon fluid exposed to the metal surface to prevent or inhibit corrosion on the metal surface, including naphthenic acid corrosion.

The present disclosure provides a formulation and methods for simultaneously dissolving metal sulfide scales, inhibiting acid gas corrosion, and inhibiting the formation of calcite and barite in a system having low or high shear stress conditions due to fluid movement, in which the formulation contains a THP+ salt, one or more corrosion inhibitors, one or more scale inhibitors, and one or more acid corrosion inhibitors. The formulation may be applied to the system in diluted or undiluted form, and continuously or in batch style.

The present disclosure provides a formulation and methods for simultaneously dissolving metal sulfide scales, inhibiting acid gas corrosion, and inhibiting the formation of calcite and barite in a system having low or high shear stress conditions due to fluid movement, in which the formulation contains a THP+ salt, one or more corrosion inhibitors, one or more scale inhibitors, and one or more acid corrosion inhibitors. The formulation may be applied to the system in diluted or undiluted form, and continuously or in batch style.

The present disclosure provides a bis-quaternary ammonium salt of Formula I

##STR00001##

wherein A is selected from O, NH, S, C(O), C(NH) or C(S); R.sub.1 and R.sub.2 are independently selected from C.sub.1-3 alkyl or H; R.sub.3 is C.sub.1-16 alkyl, C.sub.13-20 aralkyl or C.sub.2-16 allyl; X.sup.− is selected from chloro, bromo, iodo, hydroxide, nitrate or sulphate; and n and m are independently 1 to 6. Furthermore, a corrosion inhibition formulation comprising said bis-quaternary ammonium salt is revealed. Also, convenient processes for the preparation of the salt of Formula I and the formulation are provided.

Methods and compositions for inhibiting corrosion of metal surfaces in aggressive fluids, including fluids with high total dissolved solids content. The treatment composition can include a stannous corrosion inhibitor and optionally an additive that enhances the corrosion inhibition properties of the stannous component. The additive may include organic compounds having at least one heteroatom.

Disclosed herein are the methods of using di-cationic or di-anionic compounds, which are derived from primary amine through an aza-Michael addition with an activated olefin, in a corrosion control composition to mitigate corrosion of a surface in a water system. The disclosed methods or compositions are found to be more effective than those methods or compositions including commonly used single quaternary compounds for mitigating corrosion for a metal surface in water systems.

Disclosed herein are the methods of using di-cationic or di-anionic compounds, which are derived from primary amine through an aza-Michael addition with an activated olefin, in a corrosion control composition to mitigate corrosion of a surface in a water system. The disclosed methods or compositions are found to be more effective than those methods or compositions including commonly used single quaternary compounds for mitigating corrosion for a metal surface in water systems.

In a described example, a method for passivating a copper structure includes: passivating a surface of the copper structure with a copper corrosion inhibitor layer; and depositing a protection overcoat layer with a thickness less than 35 μm on a surface of the copper corrosion inhibitor layer.

In a described example, a method for passivating a copper structure includes: passivating a surface of the copper structure with a copper corrosion inhibitor layer; and depositing a protection overcoat layer with a thickness less than 35 μm on a surface of the copper corrosion inhibitor layer.