阅读说明：本技术 一种双缩合希夫碱酸化缓蚀剂、制备方法及其应用 (Double-condensation Schiff base acidizing corrosion inhibitor, preparation method and application thereof ) 是由 孙方园 薄煜 任平平 孙霜青 韩庆建 胡松青 孙志强 杨小伟 于 2019-10-15 设计创作，主要内容包括：本发明公开了一种双缩合希夫碱酸化缓蚀剂、制备方法及其应用,属于油气田开采化学防腐应用技术领域。其解决了现有技术中的酸液给管道带来的腐蚀,该酸化缓蚀剂包括组分：缓蚀剂主剂、有机溶剂、水；缓蚀剂主剂选自苯胺、2-胺基苯并咪唑或3-氨基-1,2,4-三氮唑中的一种与对苯二甲醛的混合物；苯胺/2-胺基苯并咪唑/3-氨基-1,2,4-三氮唑与对苯二甲醛的摩尔配比为2.1～2.4:1.0；有机溶剂选自无水乙醇、甲醇、N,N-二甲基甲酰胺中的一种。本发明缓蚀剂主剂用量少,容易制备且成本低；本发明缓蚀剂能在金属表面快速吸附以形成一层牢固的、疏水的缓蚀剂膜,阻碍酸液的渗透作用,可以有效地阻碍金属的腐蚀。(The invention discloses a double-condensation Schiff base acidizing corrosion inhibitor, a preparation method and application thereof, and belongs to the technical field of chemical corrosion prevention application in oil and gas field exploitation. The acidizing corrosion inhibitor solves the problem that acid liquor in the prior art causes corrosion to pipelines, and comprises the following components: a main agent of the corrosion inhibitor, an organic solvent and water; the corrosion inhibitor main agent is a mixture of terephthalaldehyde and one of aniline, 2-aminobenzimidazole or 3-amino-1, 2, 4-triazole; the molar ratio of aniline/2-aminobenzimidazole/3-amino-1, 2, 4-triazole to terephthalaldehyde is 2.1-2.4: 1.0; the organic solvent is one selected from absolute ethyl alcohol, methanol and N, N-dimethylformamide. The corrosion inhibitor has the advantages of small consumption of the main agent, easy preparation and low cost; the corrosion inhibitor can be quickly adsorbed on the surface of metal to form a firm and hydrophobic corrosion inhibitor film, so that the permeation of acid liquor is hindered, and the corrosion of the metal can be effectively hindered.)

1. The double-condensation Schiff base acidizing corrosion inhibitor is characterized by comprising the following components in percentage by mass:

main agent of corrosion inhibitor: 30% -35%;

organic solvent: 35% -45%;

water: 35% -40%;

the main agent of the corrosion inhibitor has a chemical structural formula of (1), (2) or (3):

the corrosion inhibitor main agent is a mixture of terephthalaldehyde and one of aniline, 2-aminobenzimidazole or 3-amino-1, 2, 4-triazole; the molar ratio of the aniline/2-aminobenzimidazole/3-amino-1, 2, 4-triazole to the terephthalaldehyde is 2.1-2.4: 1.0.

2. The double-condensation Schiff base acidizing corrosion inhibitor according to claim 1, wherein: the organic solvent is selected from one of absolute ethyl alcohol, methanol and N, N-dimethylformamide.

3. The method for preparing a double-condensed Schiff base acidizing corrosion inhibitor according to claim 1 or 2, wherein the method comprises the following steps: the method sequentially comprises the following steps:

s1, synthesizing a corrosion inhibitor main agent:

taking aniline/2-aminobenzimidazole/3-amino-1, 2, 4-triazole and terephthalaldehyde as raw materials for synthesizing a corrosion inhibition main agent according to a proportion, and adding the raw materials into absolute ethyl alcohol, wherein the mass of the absolute ethyl alcohol is 1.0-1.5 times of that of the raw materials; stirring, slowly dropwise adding glacial acetic acid to adjust the pH value of the solution to 6, cooling to room temperature after reaction, filtering and recrystallizing to obtain the main agent of the corrosion inhibitor;

s2, dissolving the corrosion inhibitor main agent prepared in the step S1 in an organic solvent, mixing with water and stirring uniformly to obtain the double-condensation Schiff base acidized corrosion inhibitor.

4. The double-condensation Schiff base acidizing corrosion inhibitor according to claim 3, wherein: in step S1, the reaction is carried out at 50-70 ℃ for 2-4 hours and then cooled to room temperature.

5. Use of a bis-condensed schiff base acidification corrosion inhibitor according to claim 1 or 2 in chemical corrosion prevention in oil and gas field production.

Technical Field

The invention belongs to the technical field of chemical anticorrosion application in oil and gas field exploitation, and particularly relates to an acidizing corrosion inhibitor.

Background

With the current deep development of oil and gas fields, most oil and gas fields need to be treated by adding acid liquor in the development process, so that the production is further improved, and the stable production of the oil and gas fields is realized. The oil-gas well acidification process is characterized in that a certain amount of acid liquor is injected into a stratum by a mechanical means, so that the acid liquor dissolves a blocking object in the stratum around a well bottom and partial substances in rocks, the aims of reducing oil flow resistance and increasing the width of an oil extraction channel are fulfilled, and the oil-gas recovery rate is further improved.

However, the acid liquor can corrode the exploitation equipment and devices in the filling process, and sometimes causes destructive fracture of the underground pipeline, thereby causing serious economic loss; on the other hand, the acid liquor can generate metal iron ions while corroding metals, and can pollute the stratum. Therefore, the addition of the acidification corrosion inhibitor is an indispensable protective measure in the acidification construction process.

Currently, the commonly used acidizing corrosion inhibitors mainly comprise imidazoline derivatives, Mannich base derivatives, quaternary ammonium salt derivatives and Schiff base derivatives. In contrast, schiff base (containing aromatic group) is a chemical compound formed by condensing imino (-RC ═ N-) and a substance containing an active carbonyl structure, and is an acidification corrosion inhibitor with application potential at present. Meanwhile, with the increase of the number of the deep wells and the ultra-deep wells at present, high-concentration hydrochloric acid is needed to be used in a part of regions in the acidification process. Although the recovery efficiency can be greatly improved, equipment such as pipelines and the like can be corroded.

Disclosure of Invention

One of the tasks of the invention is to provide a double-condensation Schiff base acidizing corrosion inhibitor which can effectively reduce the contact between a corrosive medium and metal and slow down corrosion.

The technical scheme adopted by the invention comprises the following steps:

the double-condensation Schiff base acidizing corrosion inhibitor is characterized by comprising the following components in percentage by mass:

main agent of corrosion inhibitor: 30% -35%;

organic solvent: 35% -45%;

water: 35% -40%;

the main agent of the corrosion inhibitor has a chemical structural formula of (1), (2) or (3):

the corrosion inhibitor main agent is a mixture of terephthalaldehyde and one of aniline, 2-aminobenzimidazole or 3-amino-1, 2, 4-triazole; the molar ratio of the aniline/2-aminobenzimidazole/3-amino-1, 2, 4-triazole to the terephthalaldehyde is 2.1-2.4: 1.0.

Further, the organic solvent is one selected from absolute ethyl alcohol, methanol and N, N-dimethylformamide.

The second task of the invention is to provide a preparation method of the double-condensation Schiff base acidizing corrosion inhibitor, which sequentially comprises the following steps:

s1, synthesizing a corrosion inhibitor main agent:

taking aniline/2-aminobenzimidazole/3-amino-1, 2, 4-triazole and terephthalaldehyde as raw materials for synthesizing a corrosion inhibition main agent according to a proportion, and adding the raw materials into absolute ethyl alcohol, wherein the mass of the absolute ethyl alcohol is 1.0-1.5 times of that of the raw materials; stirring, slowly dropwise adding glacial acetic acid to adjust the pH value of the solution to 6, cooling to room temperature after reaction, filtering and recrystallizing to obtain the main agent of the corrosion inhibitor;

s2, dissolving the corrosion inhibitor main agent prepared in the step S1 in an organic solvent, mixing with water and stirring uniformly to obtain the double-condensation Schiff base acidized corrosion inhibitor.

Further, in step S1, the reaction is carried out at 50 to 70 ℃ for 2 to 4 hours and then cooled to room temperature.

The invention also provides application of the double-condensation Schiff base acidizing corrosion inhibitor in chemical corrosion prevention in oil and gas field exploitation.

Compared with the prior art, the invention has the following beneficial technical effects:

(1) the corrosion inhibitor provided by the invention is an adsorption type corrosion inhibitor, can be quickly adsorbed on the surface of metal to form a firm and hydrophobic corrosion inhibitor film, can block the permeation of acid liquor, and can effectively block the corrosion of the metal.

(2) According to the invention, green and environment-friendly synthetic raw materials are selected, the raw materials have certain corrosion inhibition effect, the synthetic steps are simple, and the product can be obtained by recrystallization after synthesis.

(3) The corrosion inhibition main agent adopted in the invention has the advantages of small dosage, easy preparation and low cost.

(4) The corrosion inhibitor provided by the invention has good solubility, no pungent smell and stable and obvious corrosion inhibition performance.

The corrosion inhibitor provided by the invention can be quickly adsorbed on the surface of metal to form a firm and hydrophobic corrosion inhibitor film, effectively reduces the contact of a corrosive medium and the metal, slows down the corrosion, and has the characteristics of simple synthetic route, safe production and operation, low cost and environmental protection.

Drawings

The invention is further described below with reference to the accompanying drawings:

FIG. 1 is a polarization diagram of a double-condensed Schiff base type acidizing corrosion inhibitor XFJ-I in a 15% hydrochloric acid solution for N80 steel;

FIG. 2 is a graph showing the polarization of a double-condensed Schiff base type acidizing corrosion inhibitor XFJ-II of the invention in a 15% hydrochloric acid solution to N80 steel;

FIG. 3 is a plot of the polarization of a double-condensed Schiff base type acidizing corrosion inhibitor XFJ-III of the present invention in a 15% hydrochloric acid solution versus N80 steel.

Detailed Description

The invention provides a double-condensation Schiff base acidizing corrosion inhibitor, a preparation method and application thereof, and in order to make the advantages and technical scheme of the invention clearer and clearer, the invention is described in detail by combining specific embodiments.

The raw materials required by the invention can be purchased from commercial sources.

Examples 1-3 below first synthesize a corrosion inhibitor base.