Abstract: 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(CH2)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(CH2)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.

Abstract: 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(CH2)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(CH2)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.

Abstract: An aqueous acid composition that may be used, for example, in a matrix acidizing treatment can include an acid, a polymeric acid corrosion inhibitor, and an acid corrosion inhibitor intensifier. The acid corrosion inhibitor can include iodide ions and metal ions, with the metal ions being one or more of copper, silver, bismuth, or antimony. The molar ratio of metal ions to iodide ions can be 1:X, where X is greater than or equal to 2. The polymer of the polymeric acid corrosion inhibitor can have a molecular weight less than 100,000 g/mol.

Abstract: A method for measuring average thickness of a metal or alloy coating on a metal or alloy substrate using an X-ray fluorescence (XRF) spectrometer is used when the coating has an uneven surface at different distances from a measurement window of the XRF spectrometer. The method includes measuring elemental composition of the coating or substrate using the XRF spectrometer and obtaining the average thickness of the coating using a calibration relationship between coating thickness and elemental composition of the coating or substrate. The metal or alloy coating may be a metal or alloy coating of a plurality of outer armor wires wrapped around a cable. The method may be used to analyze coating thickness changes over time or along the length of the cable, or to analyze a corrosive environment in order to choose optimal material for a metal or alloy coating.

Abstract: A method for measuring a thickness of a deposit layer on a metal or alloy substrate using an X-ray fluorescence (XRF) spectrometer, where the deposit layer includes scale deposits or corrosion products. As part of the method, an elemental composition of the deposit layer or the metal or alloy substrate is measured using the XRF spectrometer. The thickness of the deposit layer is obtained from the elemental composition using a calibration relationship between deposit layer thicknesses and corresponding elemental compositions of the deposit layer or the metal/alloy substrate. The method can be applied to determine the rate of deposit layer formation and evaluate the effectiveness of a treatment.

Abstract: An aqueous acid composition that may be used, for example, in a matrix acidizing treatment can include an acid, a polymeric acid corrosion inhibitor, and an acid corrosion inhibitor intensifier. The acid corrosion inhibitor can include iodide ions and metal ions, with the metal ions being one or more of copper, silver, bismuth, or antimony. The molar ratio of metal ions to iodide ions can be 1:X, where X is greater than or equal to 2. The polymer of the polymeric acid corrosion inhibitor can have a molecular weight less than 100,000 g/mol.

Abstract: A viscosified aqueous solution, optionally for use in a subterranean wellbore, is made by reacting in aqueous solution (i) an initial polymer with either carboxylic acid or amino groups on its polymer chain, (ii) a second compound with an amino group or carboxylic acid group, and (iii) a coupling agent, so that molecules of the second compound join to the polymer chain through amide groups, thereby forming an aqueous solution of a modified polymer which, without separation from the aqueous solution, participates in cross-linking thereby enhancing viscosity of the solution. The second compound may include hydrophobic groups so that the modified polymer contains hydrophobic groups and is able to cross-link with itself or a viscoelastic surfactant through association of hydrophobic groups (without covalent bond formation) in aqueous solution. Such cross-links can reform after the fluid has been subjected to shear.

Abstract: 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(CH2)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(CH2)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.

Abstract: A corrosion inhibiting compound with a general structure A-B or A-X-B for inhibition of corrosion of steel in acidic solution. A comprises a heterocyclic ring system having a plurality of cyclic Carbon atoms and at least one cyclic Nitrogen atom, wherein the at least one cyclic Nitrogen atom is neutral under neutral conditions and protonatable under acidic conditions. B comprises at least two unsaturated Carbon atoms. B may comprise a ring system or a polymerisable group.

Abstract: An aqueous acid composition that may be used, for example, in a matrix acidizing treatment can include an acid, a polymeric acid corrosion inhibitor, and an acid corrosion inhibitor intensifier. The acid corrosion inhibitor can include iodide ions and metal ions, with the metal ions being one or more of copper, silver, bismuth, or antimony. The molar ratio of metal ions to iodide ions can be 1:X, where X is greater than or equal to 2. The polymer of the polymeric acid corrosion inhibitor can have a molecular weight less than 100,000 g/mol.

Abstract: A method of inhibiting corrosion of duplex stainless steel by aqueous acidic solution, comprises carrying out a preliminary treatment which is passivation of the steel while exposing the steel to a first aqueous acidic solution containing at least one organic corrosion inhibitor able to adsorb to a steel surface, so as to deposit a passivating and corrosion inhibiting film on the steel surface; and thereafter during a second period of time exposing the steel to a second aqueous acidic solution different from the first aqueous acidic solution and also containing at least one organic corrosion inhibitor able to adsorb to a steel. The second aqueous acidic solution maintains the film on the steel surface, such that weight loss through corrosion in the second period of time is lower than the weight loss which would be observed with the same second aqueous acidic solution but without carrying out the preliminary treatment.

Abstract: A method of inhibiting corrosion of metal which will be in contact with aqueous, and possibly acidic, solution comprises contacting the metal with a corrosion inhibiting composition containing more than 30% by weight of one or more organic corrosion inhibiting constituents which are water-insoluble hydrophobic material, and a corrosion inhibitor which contains one or more polymerisable groups containing double or triple bonded carbon, before contacting the metal with the aqueous solution. The method may be used to protect coiled tubing used for matrix acidizing of an oil well by propelling a slug of the corrosion inhibiting composition along the coiled tubing before pumping acid through the tubing.

Abstract: A corrosion inhibiting composition which is a liquid carrier in which is dissolved or dispersed a corrosion inhibitor compound comprising at least one moiety (A) which is an aliphatic, aromatic or mixed aliphatic/aromatic structure containing one or more hetero atoms which are nitrogen, oxygen, phosphorus or sulphur, and also at least one moiety (B) which contains one or more polymerisable groups containing double or triple bonded carbon, with the moieties (A) and (B) directly or indirectly covalently connected together.

Abstract: A viscosified aqueous solution, optionally for use in a subterranean wellbore, is made by reacting in aqueous solution (i) an initial polymer with either carboxylic acid or amino groups on its polymer chain, (ii) a second compound with an amino group or carboxylic acid group, and (iii) a coupling agent, so that molecules of the second compound join to the polymer chain through amide groups, thereby forming an aqueous solution of a modified polymer which, without separation from the aqueous solution, participates in cross-linking thereby enhancing viscosity of the solution. The second compound may include hydrophobic groups so that the modified polymer contains hydrophobic groups and is able to cross-link with itself or a viscoelastic surfactant through association of hydrophobic groups (without covalent bond formation) in aqueous solution. Such cross-links can reform after the fluid has been subjected to shear.

Abstract: A corrosion inhibiting compound with a general structure A-B or A-X-B for inhibition of corrosion of steel in acidic solution. A comprises a heterocyclic ring system having a plurality of cyclic Carbon atoms and at least one cyclic Nitrogen atom, wherein the at least one cyclic Nitrogen atom is neutral under neutral conditions and protonatable under acidic conditions. B comprises at least two unsaturated Carbon atoms. B may comprise a ring system or a polymerisable group.

Abstract: Corrosion of steel in acidic solution is inhibited using a mixture of a compound in which a plurality of heterocyclic aromatic groups with a quaternary nitrogen atom are connected together, such as by a linking group which may be covalently attached to the quaternary nitrogen atoms of the aromatic heterocyclic rings, and a polarizable adsorption-intensifying anion.

Abstract: A corrosion inhibiting composition which is a liquid carrier in which is dissolved or dispersed a corrosion inhibitor compound comprising at least one moiety (A) which is an aliphatic, aromatic or mixed aliphatic/aromatic structure containing one or more hetero atoms which are nitrogen, oxygen, phosphorus or sulphur, and also at least one moiety (B) which contains one or more polymerisable groups containing double or triple bonded carbon, with the moieties (A) and (B) directly or indirectly covalently connected together.

Abstract: A method of inhibiting corrosion of duplex stainless steel by aqueous acidic solution, comprises carrying out a preliminary treatment which is passivation of the steel while exposing the steel to a first aqueous acidic solution containing at least one organic corrosion inhibitor able to adsorb to a steel surface, so as to deposit a passivating and corrosion inhibiting film on the steel surface; and thereafter during a second period of time exposing the steel to a second aqueous acidic solution different from the first aqueous acidic solution and also containing at least one organic corrosion inhibitor able to adsorb to a steel. The second aqueous acidic solution maintains the film on the steel surface, such that weight loss through corrosion in the second period of time is lower than the weight loss which would be observed with the same second aqueous acidic solution but without carrying out the preliminary treatment.

Abstract: A method of inhibiting corrosion of metal which will be in contact with aqueous, and possibly acidic, solution comprises contacting the metal with a corrosion inhibiting composition containing more than 30% by weight of one or more organic corrosion inhibiting constituents which are water-insoluble hydrophobic material, and a corrosion inhibitor which contains one or more polymerisable groups containing double or triple bonded carbon, before contacting the metal with the aqueous solution. The method may be used to protect coiled tubing used for matrix acidizing of an oil well by propelling a slug of the corrosion inhibiting composition along the coiled tubing before pumping acid through the tubing.

Abstract: A wellbore fluid comprises an aqueous carrier liquid, hydrophobic fibers suspended therein, hydrophobic particulate material also suspended in the carrier liquid, and a gas to wet the surfaces of the particles and fibers and bind them together as agglomerates. The wellbore fluid may be a slickwater fracturing fluid and may be used for fracturing a tight gas reservoir. Using a combination of hydrophobic particulate material, hydrophobic fibers and gas inhibits settling out of the particulate material from an aqueous liquid. Because the gas acts to wet the surfaces of both materials and agglomerates them, the particulate material is made to adhere to the fibers; the fibers form a network which hinders settling of the particulate material adhering to them, and the agglomerates contain gas and so have a bulk density which is less than the specific gravity of the solids contained in the agglomerates.