Disclosed here are the methods of using one or more multiple charged cationic compounds in a corrosion control composition to reduce corrosion of metal surfaces in a water system. The multiple charged cationic compounds are derived from polyamines through a ring-opening reaction with an epoxide or two reactions: an aza-Michael addition with an activated olefin having a cation group and a ring-opening reaction with an epoxide. The disclosed methods or compositions are found to be effective than those methods or compositions including commonly used corrosion inhibitors for water systems.

Methods of employing corrosion inhibitors with oxidizing and/or non-oxidizing biocides, such as peroxycarboxylic acids, to provide corrosion protected compositions are disclosed. Various corrosion inhibitors further provide biocidal efficacy in addition to the corrosion protection providing further benefits for application of use. Methods of employing corrosion protected biocide compositions, such as peroxycarboxylic acid compositions, for corrosion protection are particularly well suited for treating fluids intended to flow through pipes, namely in the energy industry, water and paper industries, etc. Methods providing suitable corrosion protection in comparison to untreated systems and corrosion protected systems using conventional corrosion inhibitors, such as quaternary amines and imidazolines commonly used in the industry, are disclosed.

The present invention relates generally to methods for forming peroxyformic acid, comprising contacting formic acid with hydrogen peroxide. The methods for forming peroxyformic acid can include adding formic acid with a relatively lower concentration of hydrogen peroxide, or adding formic acid to a peroxycarboxylic acid composition or forming composition to react with hydrogen peroxide in the compositions. The present invention also relates to peroxyformic acid formed by the above methods. The present invention further relates to the uses of peroxyformic acid for treating a variety of targets, e.g., target water, including target water used in connection with oil- and gas-field operations. The present invention further relates to methods for reducing or removing H.sub.2S or iron sulfide in the treated water source, improving clarity of the treated water source, or reducing the total dissolved oxygen or corrosion in the treated water source, using peroxyformic acid, including peroxyformic acid generated in situ.

A cationic polymer salt composition is provided that includes a reaction product derived from reaction of a polyamine or a polyalkyleneimine and a substituted alkyl trialkyl quaternary ammonium salt. Also provided are surfactant compositions. The compositions may also include carriers, such as water, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, monoethyleneglycol, an ethyleneglycol monobutyl ether, and hexylene glycol.

Corrosion inhibitor compositions and methods for inhibiting corrosion on a metal surface exposed to a hydrocarbon fluid are provided. The corrosion inhibitor composition can comprise 2-aminoterephthalic acid, dimethyl sulfoxide and heavy aromatic naphtha (HAN). In another embodiment, the composition can comprise 4-methylamino benzoic acid or 4-methylsulfonyl benzoic acid, N-methyl pyrrolidone, and HAN. In the method, a corrosion inhibitor composition comprising 2-aminoterephthalic acid, 4-methylamino benzoic acid, or 4-methylsulfonyl benzoic acid can be added to a hydrocarbon fluid exposed to the metal surface. The corrosion can be caused by naphthenic acid.

Disclosed are methods of using nitrogen-containing compounds as corrosion inhibitors. The present method is used to inhibit corrosion of a metal surface in contact with an aqueous system using 2-substituted imidazoles and 2-substituted benzimidazoles, and provides enhanced protection against corrosion of metals in the aqueous system. The method comprises the use of corrosion inhibitors that are generally resistant to halogen attack and provide good corrosion resistance in the presence of oxidizing halogen-based biocides. Formulations comprising 2-substituted imidazoles and 2-substituted benzimidazoles are also disclosed.

A method for inhibiting corrosion of metal surfaces, such as carbon steel tubing, that are in contact with a fluid, such as brine in an oil and gas production fluid containing acid gases (e.g., CO.sub.2 and H.sub.2S) is accomplished by introducing a corrosion-inhibiting blend of two components into the fluid, where blend is glycolipids and quaternized amines, glycolipids and phosphate-containing compounds, quaternized amines and imidazoline-like compounds, quaternized amines and phosphate-containing compounds, or combinations of these blends. Each of the two components of the blends are present in an amount effective to synergistically inhibiting the corrosion of the metal surface when used together.

Compositions may include a corrosion inhibitor including a heterocyclic diamine prepared from the reaction of an alkyl diamine and an aldehyde, wherein the alkyl diamine has the general formula: R4NH(CH.sub.2).sub.nNHR5, where n is an integer between 3 and 6, and R4 and R5 are independently hydrogen or a C2-C30 saturated or unsaturated hydrocarbon radical. Methods may include contacting a metal surface with a corrosion inhibitor composition, wherein the corrosion inhibitor includes a heterocyclic diamine corrosion inhibitor from the reaction of an alkyl diamine and an aldehyde, wherein the alkyl diamine has the general formula: R4NH(CH.sub.2).sub.nNHR5, where n is an integer between 3 and 6, and R4 and R5 are independently hydrogen or a C2-C30 saturated or unsaturated hydrocarbon radical.

A corrosion inhibitor composition, which includes (i) a date palm leaves extract, (ii) a benzimidazole compound having at least one a carbamate group, (iii) a pyridine compound, (iv) a thiourea compound, (v) a cinnamaldehyde compound, (vi) a metal iodide, (vii) urotropin, and (viii) a base fluid containing an alcohol and an organic acid. A method of inhibiting corrosion of metal during acid cleaning is also disclosed, whereby the metal is treated with an acidic treatment fluid containing 1 to 5 wt. % of an acid, based on a total weight of the acidic treatment fluid, and 0.1 to 5 vol. % of the corrosion inhibitor composition, based on a total volume of the acidic treatment fluid.

Described herein are the methods of using a cationic alkyl polyglycoside in a corrosion control composition to reduce corrosion for metal surfaces in a water system. The described methods or compositions are found to be effective than those methods or compositions including commonly used corrosion inhibitors for water systems.