阅读说明：本技术 一种新型曼尼希碱型酸化缓蚀剂及其制备方法 (Novel Mannich base type acidizing corrosion inhibitor and preparation method thereof ) 是由 张科良 于 2021-10-11 设计创作，主要内容包括：本发明公开了一种新型曼尼希碱型酸化缓蚀剂及其制备方法,所述缓蚀剂如通式1所示：(1)；式中：甲基芳酮为萘乙酮、蒽乙酮、菲乙酮、苄叉丙酮,2-苄烯基环己酮、苯乙酮中的一种或几种的混合物或环己酮；不饱和胺为N-二烯丙基胺、N-甲基烯丙基胺、N-乙基烯丙基胺、烯丙基胺中的一种或两种以及两种以上不同混合物；醛为甲醛溶液、乙二醛或多聚甲醛粉末中的一种；反应的溶剂为甲醇、无水乙醇、异丙醇、N,N-二甲基甲酰胺中的一种或几种的混合物。本发明的新型曼尼希碱型酸化缓蚀剂具有用量少,抗腐蚀强、与其它油气田添加剂配伍良好等特点,可应用于原油常规开采酸化压裂领域。(The invention discloses a novel Mannich base type acidizing corrosion inhibitor and a preparation method thereof, wherein the corrosion inhibitor is shown as a general formula 1:)

1. A novel Mannich base type acidizing corrosion inhibitor is characterized in that the corrosion inhibitor is shown as a general formula 1:

（1）；

in the formula: the methyl arone is cyclohexanone or one or more of mixture of acetophenone, anthranone, phenacetone, benzylidene acetone, 2-benzyl alkenyl cyclohexanone and acetophenone; the unsaturated amine is one or two or more of N-diallylamine, N-methylallylamine, N-ethylallylamine and allylamine; the aldehyde is one of formaldehyde solution, glyoxal or paraformaldehyde powder; the solvent for reaction is one or a mixture of more of methanol, absolute ethyl alcohol, isopropanol and N, N-dimethylformamide.

2. The method for preparing a novel Mannich base type acidizing corrosion inhibitor according to claim 1, wherein n (aldehyde): n (methyl aryl ketone) = 0.9-1.55: 0.95-1.20: 49.5-115, the pH of the reaction medium is = 2-6, the reaction time is 5-10 hours, and the reaction temperature is 55-95 ℃.

3. The method for preparing a novel Mannich base type acidizing corrosion inhibitor according to claim 2, wherein n (aldehyde) n (methyl aryl ketone) m (unsaturated enamine) = 0.95-1.25: 0.95-1.15: 54.2-106.9; the pH of the reaction medium is = 4-5; the reaction time is 6-9 hours; the reaction temperature is 60-80 ℃.

4. The method of claim 2, wherein the method comprises the steps of: taking 35-55 mL of 95% ethanol and 4.72-6.2 g of unsaturated amine, adjusting the pH of a reaction mixture to be 2-6 by using concentrated hydrochloric acid-95% ethanol (V/V =1: 1), adding 5.7-17.3 g of methyl arone under stirring at room temperature, dropwise adding 4.06-5.1 g of 37% formaldehyde solution, glyoxal or paraformaldehyde powder after uniformly stirring, heating to 55-95 ℃, reacting for 5-10 h, and cooling to obtain the product.

Technical Field

The invention relates to the field of oilfield chemicals, and particularly relates to a novel Mannich base type acidizing corrosion inhibitor and a preparation method thereof.

Background

The acid fracturing is one of effective technical measures for increasing the yield of an oil-gas well and increasing the injection of a water injection well in the process of developing a carbonate reservoir. However, in production practice, due to the severe corrosion of oil well metal tubing by acid liquor, the acidizing stimulation technology has not been widely applied and developed until after the acidizing corrosion inhibitor is released in the 30 th 20 th century. The acidizing corrosion inhibitor is popular with people because of the advantages of small dosage, simple construction process, no need of special additional equipment (such as electrochemical protection) and the like. In the process of acidizing construction, the acidizing corrosion inhibitor is added into the acid liquor to inhibit the corrosion of the acid liquor to the underground pipe column and equipment.

The addition of the acidizing corrosion inhibitor is the most economic means for solving the corrosion problem of the oil field. Organic adsorption-type acidizing corrosion inhibitors generally include: quaternary ammonium salt, imidazoline and quaternary ammonium salt thereof, Mannich base, tannin modified product and the like. The synthesis of mannich bases is generally achieved by mannich reactions between aldehydes, ketones and amines. Generally, aldehydes include formaldehyde, benzaldehyde, cinnamaldehyde, furfural, and the like; ketones generally include: cyclohexanone, acetophenone, acetone, pentanedione, and the like; the amines include: cyclohexylamine, benzylamine, aniline, morpholine, polyethylene polyamine, hydrazine and its derivatives.

Research shows that benzimidazole derivatives substituted by alkyl, sulfydryl, amino, pyridyl, nitro, anilino and the like also have certain corrosion inhibition performance on metals (liyan, ma hui, wangyu yuye. benzimidazole and the synthesis and application research of derivatives thereof advance [ J ] organic chemistry, 2008, 28(2): 210).

The patent CN104388945A aims to solve the problem of pipeline failure such as pipeline corrosion and perforation caused by carbon dioxide corrosion in the process of high-speed transportation of natural gas. The patent takes benzimidazole, formaldehyde and diallylamine as raw materials, and prepares the main agent of the corrosion inhibitor through Mannich reaction in the presence of hydrochloric acid or acetic acid. The main agent has the characteristics of oil solubility and water dispersibility. 30-40% of a main agent, and 10-20% of benzyl alcohol, 5-10% of monoethanolamine, 5-7% of an emulsifier, and 23-50% of a solvent to prepare a final product. However, despite the presence of multi-site active adsorption groups, the water insolubility of benzimidazoles influences the solubility of the Mannich base molecules in water. In addition, mannich bases having unsaturated enamines in the molecular structure of corrosion inhibitors for acid fracturing are not currently retrieved.

Disclosure of Invention

In order to solve the problems, the invention provides a preparation method of a novel acidizing corrosion inhibitor which can be used for acidizing and fracturing, has good water solubility or water dispersibility, low compounding cost and high cost performance and has unsaturated enamine in a molecular structure.

In order to achieve the purpose, the invention adopts the technical scheme that: a novel Mannich base type acidizing corrosion inhibitor is shown as a general formula 1:

（1）；

in the formula: the methyl arone is cyclohexanone or one or more of mixture of acetophenone, anthranone, phenacetone, benzylidene acetone, 2-benzyl alkenyl cyclohexanone and acetophenone; the unsaturated amine is one or two or more of N-diallylamine, N-methylallylamine, N-ethylallylamine and allylamine; the aldehyde is one of formaldehyde solution, glyoxal or paraformaldehyde powder; the solvent for reaction is one or a mixture of more of methanol, absolute ethyl alcohol, isopropanol and N, N-dimethylformamide.

The invention also provides a preparation method of the novel Mannich base type acidizing corrosion inhibitor, wherein n (aldehyde) n (methyl aryl ketone) m (unsaturated enamine) = 0.9-1.55: 0.95-1.20: 49.5-115, the pH of a reaction medium is = 2-6, the reaction time is 5-10 hours, and the reaction temperature is 55-95 ℃.

Further, n (aldehyde) n (methyl aryl ketone) m (unsaturated enamine) = 0.95-1.25: 0.95-1.15: 54.2-106.9; the pH of the reaction medium is = 4-5; the reaction time is 6-9 hours; the reaction temperature is 60-80 ℃.

Further, the method comprises the following steps: taking 35-55 mL of 95% ethanol and 4.72-6.2 g of unsaturated amine, adjusting the pH of a reaction mixture to be 2-6 by using concentrated hydrochloric acid-95% ethanol (V/V =1: 1), adding 5.7-17.3 g of methyl arone under stirring at room temperature, dropwise adding 4.06-5.1 g of 37% formaldehyde solution, glyoxal or paraformaldehyde powder after uniformly stirring, heating to 55-95 ℃, reacting for 5-10 h, and cooling to obtain the product.

The invention has the following beneficial effects:

1) the novel Mannich base type acidizing corrosion inhibitor has the characteristics of small dosage, strong corrosion resistance, good compatibility with other oil and gas field additives and the like, can be applied to the field of acidizing and fracturing of conventional exploitation of crude oil, and can be used by being compounded with a surfactant and various auxiliaries, so that the corrosion inhibition effect is better;

2) the reaction condition is mild, and a one-pot preparation process is adopted;

3) the molecular structure and relative composition of the acidizing corrosion inhibitor can be designed according to the composition of the acidizing medium and the temperature of the corrosion medium.

Detailed Description

In order that the objects and advantages of the invention will be more clearly understood, the invention is further described in detail below with reference to examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The invention provides a preparation method of a novel Mannich base type acidizing corrosion inhibitor, which has the following preparation experimental principle:

wherein: r = phenyl, naphthyl, anthryl, phenanthryl, benzylidene, and the like; r₁= allyl, benzyl, methyl, ethyl; r₂= allyl, H; and at least one of R1 and R2 is allyl.

Example 1

And a mechanical stirrer, a reflux condenser pipe and a constant-pressure dropping funnel are installed. The reaction mixture was adjusted to pH =4 using concentrated hydrochloric acid-95% ethanol (V/V =1: 1) using 35mL of 95% ethanol and 4.858g of diallylamine, 6g of acetophenone was added with stirring at room temperature, and after stirring uniformly, 4.06g of 37% formaldehyde solution was added dropwise. Heating to 65 ℃, reacting for 9h, and cooling to obtain the product No. 1.

Example 2

And a mechanical stirrer, a reflux condenser pipe and a constant-pressure dropping funnel are installed. The reaction mixture was adjusted to pH =2 using concentrated hydrochloric acid-95% ethanol (V/V =1: 1) using 40mL of 95% ethanol and 4.858g of diallylamine, 6g of cyclohexanone was added with stirring at room temperature, and after stirring, 4.06g of 37% formaldehyde solution was added dropwise. Heating to 78 deg.C, reacting for 9h, and cooling to obtain product No. 2.

Example 3

And a mechanical stirrer, a reflux condenser pipe and a constant-pressure dropping funnel are installed. The reaction mixture was adjusted to pH =3 using concentrated hydrochloric acid-95% ethanol (V/V =1: 1) using 50mL of 95% ethanol and 4.858g of diallylamine, 7.31g of benzylidene acetone was added with stirring at room temperature, and after stirring uniformly, 4.71g of 37% formaldehyde solution was added dropwise. Heating to 55 deg.C, reacting for 9h, and cooling to obtain product # 3.

Example 4

And a mechanical stirrer, a reflux condenser pipe and a constant-pressure dropping funnel are installed. 50mL of 95% ethanol and 4.858g of diallylamine were added, the reaction mixture was adjusted to pH =5 with concentrated HCl-95% ethanol (V/V =1: 1), 7.31g of benzalacetone was added with stirring at room temperature, and after stirring, 4.47g of a 37% formaldehyde solution was added dropwise. Heating to 55 deg.C, reacting for 8h, and cooling to obtain product No. 4.

And (3) performance detection:

evaluation conditions of the acidizing corrosion inhibitor: the amount of the acidified corrosion inhibitor added is 1%, and N80 coupon is corroded for 4 hours at 90 ℃ with 15% hydrochloric acid, and the results are shown in Table 1.

TABLE 1 evaluation results of acidizing Corrosion inhibitors

The foregoing is only a preferred embodiment of the present invention, and it should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be construed as the protection scope of the present invention.