Compositions and methods are provided for reducing, inhibiting, or preventing corrosion of a surface, the polyamine compounds corresponding to the structure of Formula 1 or 2, or a salt thereof:

##STR(1)##

wherein X.sub.1 is —C(O)R.sub.9 or —[C(R.sub.10R.sub.11)].sub.p—C(R.sub.12)(X.sub.2)—R.sub.13; X.sub.2 is —OH or —NH.sub.2; R.sub.1 and R.sub.4 are independently hydrogen, alkyl, or —[C(R.sub.10R.sub.11)].sub.p—C(R.sub.12)(X.sub.2)—R.sub.13; R.sub.2, R.sub.3, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.10, R.sub.11, and R.sub.12 are independently hydrogen or alkyl; R.sub.9 and R.sub.13 are independently C.sub.7 to C.sub.30 alkyl or alkenyl; m and o are integers from 1 to 10; n is an integer from 1 to 6; and p is an integer from 1 to 10;

##STR(2)##

wherein X.sub.2 is —OH or —NH.sub.2; R.sub.21, R.sub.22, R.sub.23, R.sub.24, R.sub.25, R.sub.26, and R.sub.28 are independently hydrogen or alkyl; R.sub.27 is C.sub.10 to C.sub.30 alkyl or alkenyl; m and o are integers from 1 to 10; n is an integer from 1 to 6; and q is an integer from 0 to 10.

A method for improving the heating efficiency of steam wherein a polyamine represented by the following general formula (1) is caused to be present in a steam system to be used for heating. R.sup.1—[NH—(CH.sub.2).sub.m].sub.n—NH.sub.2 . . . (1) wherein R.sup.1 represents a saturated or unsaturated hydrocarbon group having 10 to 22 carbon atoms; m is an integer of 1 to 8, and n is an integer of 1 to 7; and when n is 2 or more, a plurality of NH—(CH.sub.2).sub.m may be identical or different.

Graphene quantum dots are functionalized by covalently bonding a corrosion inhibitor molecule thereto. In a useful method, a corrosion inhibitor compound is blended with a graphene quantum dot-tagged corrosion inhibitor compound, and the blend is applied to a metal surface, such as the interior of a carbon steel pipe. The blend inhibits corrosion arising from contact with produced water generated by hydrocarbon recovery from one or more subterranean reservoirs. The produced water having the blend dispersed therein is irradiated with a source of light having a selected first range of wavelengths, and the luminescent emission of the graphene quantum dot-tagged corrosion inhibitor is measured at a selected second range of wavelengths, thereby providing for real-time measurement of corrosion inhibitor concentration within the pipe.

Methods for providing corrosion inhibition in conduits, containers, and wellbores penetrating subterranean formations are provided. In some embodiments, the methods comprise contacting a metal surface with a fluid comprising a corrosion inhibitor additive. In certain embodiments, the corrosion inhibitor additive comprises a compound comprising a hydrophobic cation moiety, one or more lipophilic tails, and a linking moiety.

A corrosion inhibitor composition, containing (a) a cinnamaldehyde compound, (b) an alkoxylated fatty amine, and (c) an imidazoline compound, and optionally (d) a surfactant, and (e) a solvent. A method of inhibiting corrosion of metal in contact with an acidic medium in an oil or gas field environment by introducing the corrosion inhibitor composition into the acidic medium, such as during acid stimulation operations.

A method for inhibiting corrosion of pipelines and other metal surfaces, particularly those used in the oil-and-gas industry, is disclosed. The method comprises treating a brine-exposed metal surface with a film-forming composition. The composition comprises a quaternary surfactant, which is made by reacting a polyalkylene glycol (PAG), a haloalkanoic acid, and a tertiary fatty amine that optionally incorporates amide or ester functionality. The surfactant comprises a PAG monoester quat and a PAG diester diquat and may have other components. The quaternary surfactants provide good corrosion protection and can partition effectively from an oily phase into a brine phase in the absence of agitation. The surfactants are easy to synthesize economically and have structures that can be tailored to meet local HLB requirements.

A method for reducing or preventing corrosion or fouling in an apparatus for carrying out a chemical process, where corrosion or fouling is caused by acidic compounds present in the chemical process, which comprises the addition of at least one quaternary ammonium hydroxide of the formula (I) to the apparatus, wherein the chemical process is carried out: [Chem. 1] where R.sup.1, R.sup.2, R.sup.3 are each independently C.sub.1-C.sub.10 alkyl; R.sup.4 is inter alia C.sub.1-C.sub.18 alkyl, benzyl, monocycloalkyl having 5, 6, 7 or 8 carbon atoms, bicycloalkyl having 6 to 8 carbon atoms, tricycloalkyl having 7 to 10 carbon atoms, where monocycloalkyl, bicycloalkyl and tricycloalkyl are unsubstituted or substituted by 1 or 2 methyl groups, or tri-C.sub.1-C.sub.4 alkyl ammonium groups. R.sup.1 and R.sup.2 together with the nitrogen atom may also form a 5 or 6-membered, saturated nitrogen heterocycle, which is unsubstituted or carries 1 or 2 methyl groups; and/or R.sup.3 and R.sup.4 together with the nitrogen atom may also form a 5 or 6-membered, saturated nitrogen heterocycle, which is unsubstituted or carries 1 or 2 methyl groups.

Corrosion inhibitor compositions for reducing the corrosive effect of acidic environments on metallic substrates are provided herein. In particular, the present disclosure describes corrosion inhibitor compositions comprising a condensation product of a trifunctional amine and a fatty acid. The present disclosure also describes methods of preparing and of using such corrosion inhibitor compositions.

Disclosed are succinic anhydride-derived polyester compounds used in compositions and methods for inhibiting corrosion.

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.