A high-strength hot-dip galvanized steel sheet includes a hot-dip galvanized layer on a surface of the steel sheet and has a specific component composition and a steel microstructure containing, on an area percentage basis, 90% to 100% of martensite and carbide-containing bainite in total and 0% to 10% of retained austenite, and containing prior austenite grains having an aspect ratio of 2.0 or less, in a region extending from 300 μm to 400 μm from the surface layer, in which the ratio of the average amount of C at 5 μm from the surface layer to the average amount of C at 70 μm from the surface layer is 0.2 to 0.8, and the ratio of the standard deviation of the amount of C to the average amount of C in a region extending from 300 μm to 400 μm from the surface layer is 0.40 or less.

A high-strength hot-dip galvanized steel sheet includes a hot-dip galvanized layer on a surface of the steel sheet and has a specific component composition and a steel microstructure containing, on an area percentage basis, 90% to 100% of martensite and carbide-containing bainite in total and 0% to 10% of retained austenite, and containing prior austenite grains having an aspect ratio of 2.0 or less, in a region extending from 300 μm to 400 μm from the surface layer, in which the ratio of the average amount of C at 5 μm from the surface layer to the average amount of C at 70 μm from the surface layer is 0.2 to 0.8, and the ratio of the standard deviation of the amount of C to the average amount of C in a region extending from 300 μm to 400 μm from the surface layer is 0.40 or less.

A cleaning solution for a turbine engine includes water; a first organic acidic component that comprises citric acid; a second organic acidic component that comprises glycolic acid; isopropylamine sulphonate; alcohol ethoxylate; triethanol amine; and sodium lauriminodipropionate. The cleaning solution has a pH value between about 2.5 and about 7.0.

A cleaning solution for a turbine engine includes water; a first organic acidic component that comprises citric acid; a second organic acidic component that comprises glycolic acid; isopropylamine sulphonate; alcohol ethoxylate; triethanol amine; and sodium lauriminodipropionate. The cleaning solution has a pH value between about 2.5 and about 7.0.

A multifunctional coating method involves cleaning a surface, applying a layer of corrosion-resistant alloy coating to the surface, and applying an oleo-hydrophobic composite coating over the corrosion-resistant alloy coating. An oil and gas pipe has an inner surface with a multifunctional coating applied using the multifunctional coating method, and has an inner oleo-hydrophobic composite coating, beneath the inner oleo-hydrophobic composite coating a corrosion-resistant alloy coating, and beneath the corrosion-resistant alloy coating untreated pipe or any other metallic substrate.

A multifunctional coating method involves cleaning a surface, applying a layer of corrosion-resistant alloy coating to the surface, and applying an oleo-hydrophobic composite coating over the corrosion-resistant alloy coating. An oil and gas pipe has an inner surface with a multifunctional coating applied using the multifunctional coating method, and has an inner oleo-hydrophobic composite coating, beneath the inner oleo-hydrophobic composite coating a corrosion-resistant alloy coating, and beneath the corrosion-resistant alloy coating untreated pipe or any other metallic substrate.

A cleaning system and method uses a tank holding a fluid detergent and an equipment assembly formed from a plurality of discrete components joined together. One or more ultrasound transducers remove one or more deposits on the equipment assembly by generating and propagating high frequency ultrasound waves into the fluid detergent while the equipment assembly is in contact with the fluid detergent.

A cleaning system and method uses a tank holding a fluid detergent and an equipment assembly formed from a plurality of discrete components joined together. One or more ultrasound transducers remove one or more deposits on the equipment assembly by generating and propagating high frequency ultrasound waves into the fluid detergent while the equipment assembly is in contact with the fluid detergent.

An aqueous synthetic acid composition is disclosed for use in oil industry activities, the composition comprising: lysine and hydrogen chloride in a molar ratio ranging from 1:3 to 1:12.5, preferably from more than 1:5 to 1:8.5. The composition can also further comprise a metal iodide or iodate; an alcohol or derivative thereof. The composition demonstrates advantageous properties over known synthetic acids at temperatures above 90° C. The composition is useful in various oil and gas industry operations. Preferred embodiments of the composition provide substantial advantages in matrix acidizing by increasing the effectiveness of wormholing as compared to conventional mineral acids such as HC1.

An aqueous synthetic acid composition is disclosed for use in oil industry activities, the composition comprising: lysine and hydrogen chloride in a molar ratio ranging from 1:3 to 1:12.5, preferably from more than 1:5 to 1:8.5. The composition can also further comprise a metal iodide or iodate; an alcohol or derivative thereof. The composition demonstrates advantageous properties over known synthetic acids at temperatures above 90° C. The composition is useful in various oil and gas industry operations. Preferred embodiments of the composition provide substantial advantages in matrix acidizing by increasing the effectiveness of wormholing as compared to conventional mineral acids such as HC1.