Adsorbed film type imidazoline corrosion inhibitor and preparing method thereof

Abstract

The invention discloses an adsorbed type imidazoline corrosion inhibitor and a preparing method thereof. The structural formula of the imidazoline corrosion inhibitor is shown in the description, wherein R is linear-chain or branched-chain hydrocarbon or aromatic hydrocarbon which has 1-20 C atoms, X is N or O, and n is 1-8. The invention further discloses the preparing method of the imidazoline corrosion inhibitor. The preparing method comprises the steps of firstly conducting reaction between trimesic acid and methyl alcohol, conducting esterification and hydroluysis on trimesic acid and methyl alcohol to obtain trimesic acid monomethylester, conducting reaction between trimesic acid monomethylester and paraffin amine in methylbenzene to obtain 5-(alkyl amine formyl)-1,3-phthalic acid, finally adopting 5-(alkyl amine formyl)-1,3-phthalic acid as a raw material, and conducting two-step dehydration on 5-(alkyl amine formyl)-1,3-phthalic acid together with polyethylene polyamine to obtain the imidazoline corrosion inhibitor. According to the adsorbed type imidazoline corrosion inhibitor and the preparing method thereof, the corrosion inhibitor has multiple adsorption centers, through chelation of the multiple adsorption centers in the molecular structure of the corrosion inhibitor, the corrosion inhibitor is capable of forming a stable and firm adsorbed layer on the surface of a metal so as to prevent a corrosive medium from corroding the surface of the metal, and adsorption strength and corrosion inhibition performance of an adsorbed film of the corrosion inhibitor is improved.

Description

technical field [0001] The invention relates to the technical field of oilfield chemicals, in particular to an adsorption film-forming imidazoline corrosion inhibitor and a preparation method. Background technique [0002] With the rapid development of the offshore oilfield mining industry, the 2 The exploitation of oil and gas fields is also gradually increasing. Since the downhole temperature can be as high as 150°C, it belongs to the harsh H 2 S / CO 2 The corrosive environment, coupled with the pressure difference between the formation and the oil and gas well, forms a large amount of elemental sulfur, which greatly deteriorates the corrosive environment. in high H 2 S, CO 2 , elemental sulfur, high temperature, high pressure, and high flow rate media, the existing imidazoline corrosion inhibitors are difficult to adsorb and form films on the steel surface, resulting in their corrosion inhibition performance not meeting production needs. The main reason is that the in...

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Problems solved by technology

On the other hand: the shear stress generated by the fluid flow will have an impact on the corrosion inhibitor film, causing the film layer to break and fall off, shortening the life of the corrosion inhibitor film, which is generally considered the highest critical flow strength

For a specific corrosion inhibitor, it can only be used below a certain flow rate, otherwise the corrosion inhibitor will fall off quickly, lose its corrosion inhibition effect, and it is difficult to block H 2 S and CO 2 Corrosion to carbon steel

Existing imidazoline corrosion inhibitors in high temperature, high pressure, H 2 S, CO 2 1. The efficiency of adsorption and film formation on the steel surface is reduced in high flow rate and harsh corrosion environment, resulting in a decrease in its corrosion inhibition effect. The development and production of oilfields urgently require the development and application of new corrosion inhibitors with stronger adsorption and film formation performance.

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