CN118755468A - Acidizing corrosion inhibitor for oil and gas well fracturing and preparation method thereof - Google Patents

Abstract

The invention discloses an acidizing corrosion inhibitor for oil and gas well fracturing and a preparation method thereof, comprising the following components: o-methoxybenzaldehyde modified meso-tetramethyl-meso-tetra-aminophenyl cup [4] pyrrole, amphoteric organic ion salt, diazolidinyl urea, hydroxypropyl trimethyl ammonium chloride chitosan, bis (2-hydroxyethyl) amino (trimethylol) methane, lauryl hydroxyethyl imidazoline, urotropine, nonionic fluorocarbon surfactant, dodecyl trimethyl ammonium chloride, APG 1214 surfactant, cosolvent and water. The acidizing corrosion inhibitor has a small amount of use, a significant corrosion inhibition effect, good high temperature resistance, high cost performance, and safe and environmentally friendly use.

Description

Acidizing corrosion inhibitor for oil and gas well fracturing and preparation method thereof

Technical Field

The invention relates to the technical field of oilfield additives, and in particular to an acidizing corrosion inhibitor for oil and gas well fracturing and a preparation method thereof.

Background Art

In the process of oil and gas resource development, acid fracturing construction is one of the effective measures to increase and stabilize the production of oil and gas fields. However, high-concentration acid will cause serious corrosion to the oil well pipe and downhole metal equipment. In order to reduce the corrosion of acid, a certain proportion of acid corrosion inhibitor must be added to the acid. With the continuous development of oil and gas wells, the well temperature continues to rise, and the corrosion of acid to metal is intensified, which puts higher requirements on the performance of acid corrosion inhibitor.

Currently, the mainstream acidizing corrosion inhibitors on the market are mainly quinoline quaternary ammonium salts, pyridine quaternary ammonium salts, aldehyde ketoamine condensates, etc. They have more or less high content of toxic and harmful substances, cause serious environmental pollution, have complex production processes, do not conform to the green concept of energy conservation and environmental protection, are not very versatile, have high production costs, poor thermal stability, are prone to coking and stratification at high temperatures, have unstable solubility and dispersion properties, and may cause formation damage and other technical defects.

For example, the Chinese invention patent with the authorization announcement number CN104233310B discloses a composite imidazoline quaternary ammonium salt corrosion inhibitor and its preparation method that can be used in oil and gas wells, gathering and transportation systems, and water injection processes in oil fields. The slow-release agent contains, by mass percentage: 30wt% to 35wt% of alkyl acid imidazoline quaternary ammonium salt, 8wt% to 10wt% of nitrogen-containing organic polyphosphate, 1wt% to 2wt% of amphoteric surfactant, 0.5wt% to 1wt% of dispersant, 1wt% to 2wt% of cosolvent, and the balance is water. The corrosion inhibitor of the present invention has a corrosion inhibition rate of more than 70% under 50°C self-prepared simulated water with a dosage of 50ppm. However, its formula is complicated, the cost is high, and it is not conducive to environmental protection.

It can be seen that the development of an acidizing corrosion inhibitor for oil and gas well fracturing, which has a small usage amount, significant corrosion inhibition effect, good high temperature resistance, high cost performance, safe and environmentally friendly use, and its preparation method meets the market demand, has broad market value and application prospects, and is of great significance to promoting the development of the corrosion inhibitor field and acidizing fracturing construction technology.

Summary of the invention

The main purpose of the present invention is to provide an acidizing corrosion inhibitor for oil and gas well fracturing, which has small usage amount, significant corrosion inhibition effect, good high temperature resistance, high cost performance, safe use and environmental protection, and a preparation method thereof.

To achieve the above object, the present invention provides an acidizing corrosion inhibitor for oil and gas well fracturing, comprising the following components in weight percentage: 0.3wt%-0.6wt% of o-anisaldehyde modified meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole, 0.8wt%-1.2wt% of amphoteric organic ion salt, 0.1wt%-0.4wt% of diazolidinyl urea, 1wt%-3wt% of hydroxypropyltrimethylammonium chloride chitosan, 1wt%-3wt% of bis(2-hydroxyethyl)amino(trihydroxymethyl)methane, 0.2wt%-0.4wt% of lauryl hydroxyethyl imidazoline, 0.8wt%-1.2wt% of urotropine, 0.1wt%-1wt% of nonionic fluorocarbon surfactant, 4wt%-8wt% of dodecyltrimethylammonium chloride, 8wt%-25wt% of APG 1214 surfactant, 3wt%-5wt% of cosolvent, and the balance is water.

Preferably, the preparation method of the o-anisaldehyde modified meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole comprises the following steps: under the protection of inert gas, adding meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole into a three-necked reaction bottle, adding anhydrous ethanol with a mass 3-5 times that of meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole and stirring evenly, slowly dropping anhydrous ethanol solution of o-anisaldehyde while stirring, and dripping it within 1 hour. After dripping, stirring and reacting at 65-90° C. for 3-5 hours, cooling and filtering to obtain a filter cake, recrystallizing the filter cake with anhydrous ethanol for 3-5 times, and vacuum drying to obtain o-anisaldehyde modified meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole.

Preferably, the inert gas is any one of nitrogen, helium, neon and argon.

Preferably, the molar ratio of meso-tetramethyl-meso-tetra-p-aminophenylcalix[4]pyrrole to o-anisaldehyde is 1:4.

Preferably, the preparation method of the meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole is described in: Guo Yong, Shao Shijun, He Lijun, et al. Synthesis and Characterization of Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole [J]. Chemical Reagents, 2002(6):344-345.

Preferably, the mass percentage concentration of the anhydrous ethanol solution of o-anisaldehyde is 5wt%-10wt%.

Preferably, the amphoteric organic ion salt is at least one of hydroxypropane sulfonate pyridinium salt and 1-benzylpyridine-3-carboxylate; the number average molecular weight of the hydroxypropyltrimethylammonium chloride chitosan is 100,000, and the degree of substitution is 90%.

Preferably, the nonionic fluorocarbon surfactant is a fluorocarbon surfactant of model ZY-FC368, provided by Shanghai Ziyi Chemical Co., Ltd.

Preferably, the co-solvent is at least one of ethanol and methanol.

Another object of the present invention is to provide a method for preparing the acidizing corrosion inhibitor for oil and gas well fracturing, comprising the following steps: mixing the components uniformly according to weight percentage, vacuuming and degassing, and naturally standing for 1-3 hours to prepare the acidizing corrosion inhibitor for oil and gas well fracturing.

Due to the application of the above technical solution, the present invention has the following beneficial effects:

(1) The method for preparing the acidizing corrosion inhibitor for oil and gas well fracturing disclosed in the present invention only requires mixing the components uniformly according to weight percentage and then degassing. No special equipment is required, capital investment is small, energy consumption is low, preparation efficiency and finished product qualification rate are high, labor intensity is low, and environmental impact is small, which is suitable for continuous large-scale production.

(2) The acidizing corrosion inhibitor for oil and gas well fracturing disclosed in the present invention comprises the following components in percentage by weight: 0.3wt%-0.6wt% of o-anisaldehyde-modified meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole, 0.8wt%-1.2wt% of amphoteric organic ion salt, 0.1wt%-0.4wt% of diazolidinyl urea, 1wt%-3wt% of hydroxypropyltrimethylammonium chloride chitosan, 1wt%-3wt% of bis(2-hydroxyethyl)amino(trihydroxymethyl)methane, 0.2wt%-0.4wt% of lauryl hydroxyethyl imidazoline, 0.8wt%-1.2wt% of urotropine, 0.1wt%-1wt% of nonionic fluorocarbon surfactant, 4wt%-8wt% of dodecyltrimethylammonium chloride, 8wt%-25wt% of APG 1214 surfactant, 3wt%-5wt% of cosolvent, and the balance is water. Through the mutual cooperation between the components, the acidizing corrosion inhibitor has a small usage, significant corrosion inhibition effect, good high temperature resistance, high cost performance, and is safe and environmentally friendly to use.

(3) The acidizing corrosion inhibitor for oil and gas well fracturing disclosed in the present invention can effectively improve the surface activity, improve the dispersion uniformity and mutual compatibility of each component through the reasonable selection of component types and dosage ratios, thereby improving the stability of the corrosion inhibitor and making its corrosion inhibition effect more significant; by adding o-anisaldehyde to modify meso-tetramethyl-meso-tetraaminophenyl cup[4]pyrrole, the carbon-nitrogen double bonds, benzene rings and cuppyrrole introduced at the same time can enhance the adsorption capacity of the corrosion inhibitor molecules on the metal surface and enhance the corrosion inhibition effect; by cooperating with hydroxypropyltrimethylammonium chloride chitosan and dodecyltrimethylammonium chloride, the amount of acidizing corrosion inhibitor used is reduced, the corrosion inhibition effect is more significant, the high temperature resistance is better, and the cost performance is higher.

DETAILED DESCRIPTION

The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.

Example 1. An acidizing corrosion inhibitor for oil and gas well fracturing, comprising the following components in percentage by weight: 0.3 wt % of o-anisaldehyde-modified meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole, 0.8 wt % of amphoteric organic ion salt, 0.1 wt % of diazolidinyl urea, 1 wt % of hydroxypropyltrimethylammonium chloride chitosan, 1 wt % of bis(2-hydroxyethyl)amino(trihydroxymethyl)methane, 0.2 wt % of lauryl hydroxyethyl imidazoline, 0.8 wt % of urotropine, 0.1 wt % of nonionic fluorocarbon surfactant, 4 wt % of dodecyltrimethylammonium chloride, 8 wt % of APG 1214 surfactant, 3 wt % of cosolvent, and the balance being water.

The preparation method of o-anisaldehyde modified meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole comprises the following steps: under the protection of inert gas, adding meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole into a three-necked reaction bottle, adding anhydrous ethanol with a mass three times that of meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole and stirring evenly, slowly dropping anhydrous ethanol solution of o-anisaldehyde while stirring, and dripping it within 1 hour, and after dripping, continuing to stir and react at 65° C. for 3 hours, cooling, filtering and obtaining a filter cake, and filtration the filter cake with anhydrous ethanol. Recrystallize three times and vacuum dry to obtain o-anisaldehyde modified meso-tetramethyl-meso-tetraaminophenyl-calix[4]pyrrole; the inert gas is nitrogen; the molar ratio of meso-tetramethyl-meso-tetraaminophenyl-calix[4]pyrrole to o-anisaldehyde is 1:4; the preparation method of meso-tetramethyl-meso-tetraaminophenyl-calix[4]pyrrole, see: Guo Yong, Shao Shijun, He Lijun, et al. Synthesis and Characterization of Meso-tetramethyl-meso-tetraaminophenyl-calix[4]pyrrole [J]. Chemical Reagents, 2002 (6): 344-345. The presence of carbon-nitrogen double bond structure in the product was verified by infrared analysis, confirming the occurrence of the above modification reaction.

The mass percentage concentration of the anhydrous ethanol solution of o-anisaldehyde is 5wt%; the amphoteric organic ion salt is hydroxypropane sulfonate pyridinium salt; the non-ionic fluorocarbon surfactant is a fluorocarbon surfactant with model number ZY-FC368, provided by Shanghai Ziyi Chemical Co., Ltd.; the number average molecular weight of the hydroxypropyltrimethylammonium chloride chitosan is 100,000, and the degree of substitution is 90%; the cosolvent is ethanol.

A method for preparing the acidizing corrosion inhibitor for oil and gas well fracturing comprises the following steps: mixing the components uniformly according to weight percentage, vacuuming and degassing, and letting the mixture stand naturally for 1 hour to prepare the acidizing corrosion inhibitor for oil and gas well fracturing.

Example 2, an acidizing corrosion inhibitor for oil and gas well fracturing, comprising the following components in percentage by weight: 0.4wt% of o-anisaldehyde-modified meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole, 0.9wt% of amphoteric organic ion salt, 0.2wt% of diazolidinyl urea, 1.5wt% of hydroxypropyltrimethylammonium chloride chitosan, 1.5wt% of bis(2-hydroxyethyl)amino(trihydroxymethyl)methane, 0.25wt% of lauryl hydroxyethyl imidazoline, 0.9wt% of methenamine, 0.3wt% of nonionic fluorocarbon surfactant, 5wt% of dodecyltrimethylammonium chloride, 13wt% of APG 1214 surfactant, 3.5wt% of cosolvent, and the balance is water.

The preparation method of o-anisaldehyde modified meso-tetramethyl-meso-tetra-p-aminophenyl calix[4]pyrrole comprises the following steps: under the protection of inert gas, adding meso-tetramethyl-meso-tetra-p-aminophenyl calix[4]pyrrole into a three-necked reaction bottle, adding anhydrous ethanol with a mass 3.5 times that of meso-tetramethyl-meso-tetra-p-aminophenyl calix[4]pyrrole and stirring evenly, slowly dropping anhydrous ethanol solution of o-anisaldehyde while stirring, and dripping it within 1 hour, and then continuing to heat at 70°C after dripping. The reaction was continued with stirring for 3.5 hours, and the mixture was cooled and filtered to obtain a filter cake, which was recrystallized four times with anhydrous ethanol and dried in vacuo to obtain o-anisaldehyde-modified meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole; the inert gas was helium; the molar ratio of meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole to o-anisaldehyde was 1:4; the preparation method of meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole, see: Guo Yong, Shao Shijun, He Lijun, et al. Synthesis and Characterization of Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole [J]. Chemical Reagents, 2002(6):344-345.

The mass percentage concentration of the anhydrous ethanol solution of o-anisaldehyde is 7wt%; the amphoteric organic ion salt is 1-benzylpyridine-3-carboxylate; the non-ionic fluorocarbon surfactant is a fluorocarbon surfactant with model number ZY-FC368, provided by Shanghai Ziyi Chemical Co., Ltd.; the number average molecular weight of the hydroxypropyltrimethylammonium chloride chitosan is 100,000, and the degree of substitution is 90%; the cosolvent is methanol.

A method for preparing the acidizing corrosion inhibitor for oil and gas well fracturing comprises the following steps: mixing the components uniformly according to weight percentage, vacuuming and degassing, and letting the mixture stand naturally for 1.5 hours to prepare the acidizing corrosion inhibitor for oil and gas well fracturing.

Example 3, an acidizing corrosion inhibitor for oil and gas well fracturing, comprising the following components in percentage by weight: 0.45wt% of o-anisaldehyde-modified meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole, 1wt% of amphoteric organic ion salt, 0.25wt% of diazolidinyl urea, 2wt% of hydroxypropyltrimethylammonium chloride chitosan, 2wt% of bis(2-hydroxyethyl)amino(trihydroxymethyl)methane, 0.3wt% of lauryl hydroxyethyl imidazoline, 1wt% of urotropine, 0.7wt% of nonionic fluorocarbon surfactant, 6wt% of dodecyltrimethylammonium chloride, 18wt% of APG 1214 surfactant, 4wt% of cosolvent, and the balance is water.

The preparation method of o-anisaldehyde modified meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole comprises the following steps: under the protection of inert gas, adding meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole into a three-necked reaction bottle, adding anhydrous ethanol with a mass of 4 times that of meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole and stirring evenly, slowly dropping anhydrous ethanol solution of o-anisaldehyde while stirring, and dripping it within 1 hour, and after dripping, continuing to stir and react at 80° C. for 4 hours, cooling, filtering and obtaining a filter cake, recrystallizing the filter cake with anhydrous ethanol for 4 times, and vacuum drying to obtain o-anisaldehyde. Oxybenzaldehyde modified meso-tetramethyl-meso-tetraaminophenyl cup [4] pyrrole; the inert gas is neon; the molar ratio of the meso-tetramethyl-meso-tetraaminophenyl cup [4] pyrrole to o-anisaldehyde is 1:4; the preparation method of the meso-tetramethyl-meso-tetraaminophenyl cup [4] pyrrole, see: Guo Yong, Shao Shijun, He Lijun, et al. Synthesis and Characterization of Meso-tetramethyl-meso-tetraaminophenyl cup [4] pyrrole [J]. Chemical Reagents, 2002 (6): 344-345; the mass percentage concentration of the anhydrous ethanol solution of o-anisaldehyde is 8wt%.

The amphoteric organic ion salt is hydroxypropane sulfonic acid pyridinium salt; the nonionic fluorocarbon surfactant is a fluorocarbon surfactant with model number ZY-FC368, provided by Shanghai Ziyi Chemical Co., Ltd.; the number average molecular weight of the hydroxypropyltrimethylammonium chloride chitosan is 100,000, and the degree of substitution is 90%; the cosolvent is ethanol.

A method for preparing the acidizing corrosion inhibitor for oil and gas well fracturing comprises the following steps: mixing the components uniformly according to weight percentage, vacuuming and degassing, and letting the mixture stand naturally for 2 hours to prepare the acidizing corrosion inhibitor for oil and gas well fracturing.

Example 4, an acidizing corrosion inhibitor for oil and gas well fracturing, comprising the following components in weight percentage: 0.55wt% of o-anisaldehyde-modified meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole, 1.1wt% of amphoteric organic ion salt, 0.35wt% of diazolidinyl urea, 2.5wt% of hydroxypropyltrimethylammonium chloride chitosan, 2.5wt% of bis(2-hydroxyethyl)amino(trihydroxymethyl)methane, 0.35wt% of lauryl hydroxyethyl imidazoline, 1.1wt% of urotropine, 0.9wt% of nonionic fluorocarbon surfactant, 7.5wt% of dodecyltrimethylammonium chloride, 23wt% of APG 1214 surfactant, 4.5wt% of cosolvent, and the balance is water.

The preparation method of o-anisaldehyde modified meso-tetramethyl-meso-tetra-p-aminophenyl calix[4]pyrrole comprises the following steps: under the protection of inert gas, adding meso-tetramethyl-meso-tetra-p-aminophenyl calix[4]pyrrole into a three-necked reaction bottle, adding anhydrous ethanol with a mass 4.5 times that of meso-tetramethyl-meso-tetra-p-aminophenyl calix[4]pyrrole and stirring evenly, slowly dropping anhydrous ethanol solution of o-anisaldehyde while stirring, and dripping it within 1 hour, and then heating it at 85°C after dripping it. The reaction was continued with stirring for 4.5 hours, and the mixture was cooled and filtered to obtain a filter cake. The filter cake was recrystallized from anhydrous ethanol for 5 times and dried in vacuo to obtain o-anisaldehyde-modified meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole; the inert gas was argon; the molar ratio of meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole to o-anisaldehyde was 1:4; the preparation method of meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole, see: Guo Yong, Shao Shijun, He Lijun, et al. Synthesis and Characterization of Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole [J]. Chemical Reagents, 2002(6):344-345; the mass percentage concentration of the anhydrous ethanol solution of o-anisaldehyde was 9wt%.

The amphoteric organic ion salt is a mixture of hydroxypropane sulfonate pyridinium salt and 1-benzylpyridine-3-carboxylate in a mass ratio of 3:5; the non-ionic fluorocarbon surfactant is a fluorocarbon surfactant with model number ZY-FC368, provided by Shanghai Ziyi Chemical Co., Ltd.; the number average molecular weight of the hydroxypropyltrimethylammonium chloride chitosan is 100,000, and the degree of substitution is 90%; the cosolvent is a mixture of ethanol and methanol in a mass ratio of 1:2.

A method for preparing the acidizing corrosion inhibitor for oil and gas well fracturing comprises the following steps: mixing the components uniformly according to weight percentage, vacuuming and degassing, and letting the mixture stand naturally for 2.5 hours to prepare the acidizing corrosion inhibitor for oil and gas well fracturing.

Example 5, an acidizing corrosion inhibitor for oil and gas well fracturing, comprising the following components in weight percentage: 0.6wt% of o-anisaldehyde-modified meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole, 1.2wt% of amphoteric organic ion salt, 0.4wt% of diazolidinyl urea, 3wt% of hydroxypropyltrimethylammonium chloride chitosan, 3wt% of bis(2-hydroxyethyl)amino(trihydroxymethyl)methane, 0.4wt% of lauryl hydroxyethyl imidazoline, 1.2wt% of urotropine, 1wt% of nonionic fluorocarbon surfactant, 8wt% of dodecyltrimethylammonium chloride, 25wt% of APG 1214 surfactant, 5wt% of cosolvent, and the balance is water.

The preparation method of o-anisaldehyde modified meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole comprises the following steps: under the protection of inert gas, adding meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole into a three-necked reaction bottle, adding anhydrous ethanol with a mass 5 times that of meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole and stirring evenly, slowly dropping anhydrous ethanol solution of o-anisaldehyde while stirring, and dripping it within 1 hour, after dripping, continuing to stir and react at 90° C. for 5 hours, cooling, filtering to obtain a filter cake, recrystallizing the filter cake with anhydrous ethanol for 5 times, and vacuum drying to obtain o-anisaldehyde. Oxybenzaldehyde modified meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole; the inert gas is nitrogen; the molar ratio of meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole to o-anisaldehyde is 1:4; the preparation method of meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole, see: Guo Yong, Shao Shijun, He Lijun, et al. Synthesis and Characterization of Meso-tetramethyl-meso-tetraaminophenylcalix[4]pyrrole [J]. Chemical Reagents, 2002(6):344-345; the mass percentage concentration of the anhydrous ethanol solution of o-anisaldehyde is 10wt%.

The amphoteric organic ion salt is hydroxypropane sulfonic acid pyridinium salt; the nonionic fluorocarbon surfactant is a fluorocarbon surfactant with model number ZY-FC368, provided by Shanghai Ziyi Chemical Co., Ltd.; the number average molecular weight of the hydroxypropyltrimethylammonium chloride chitosan is 100,000, and the degree of substitution is 90%; the cosolvent is ethanol.

A method for preparing the acidizing corrosion inhibitor for oil and gas well fracturing comprises the following steps: mixing the components uniformly according to weight percentage, vacuuming and degassing, and naturally standing for 3 hours to prepare the acidizing corrosion inhibitor for oil and gas well fracturing.

Comparative Example 1

An acidizing corrosion inhibitor for oil and gas well fracturing and a preparation method thereof, which is basically the same as Example 1, except that meso-tetramethyl-meso-tetra-p-aminophenylcalix[4]pyrrole is used instead of o-anisaldehyde to modify meso-tetramethyl-meso-tetra-p-aminophenylcalix[4]pyrrole.

Comparative Example 2

An acidizing corrosion inhibitor for oil and gas well fracturing and a preparation method thereof are substantially the same as those in Example 1, except that diazolidinyl urea and hydroxypropyltrimethylammonium chloride chitosan are not added.

In order to further illustrate the beneficial technical effects of the acidizing corrosion inhibitor for oil and gas well fracturing involved in each embodiment of the present invention, the relevant performance tests were carried out on the acidizing corrosion inhibitor for oil and gas well fracturing involved in Examples 1-5 and Comparative Examples 1-2. The test results are shown in Table 1. The test method is as follows:

(1) According to the experimental method of corrosion rate in the petroleum and natural gas industry standard SY/5405-1996 "Performance Test Method and Evaluation Index of Acidizing Inhibitors", each acidizing corrosion inhibitor sample was tested. The corrosion rate of N80 steel sheet at different temperatures was tested in 20% HCl solution. The experimental time was 4h, and the test temperature was 90℃ and 140℃. The addition amount of corrosion inhibitor was 1wt%.

(2) According to the experimental method for the solubility and dispersibility of corrosion inhibitors in the petroleum and natural gas industry standard SY/5405-1996 "Performance Test Methods and Evaluation Indicators for Acidizing Inhibitors", the solubility and dispersibility of each acidizing corrosion inhibitor sample was tested after being placed in a 20% HCl solution for 7 days.

Table 1

It can be seen from Table 1 that the acidizing corrosion inhibitor for oil and gas well fracturing disclosed in each embodiment of the present invention has a better corrosion inhibition effect than the comparative product, and has good solubility and dispersibility; the addition of o-anisaldehyde-modified meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole, diazolidinyl urea and hydroxypropyltrimethylammonium chloride chitosan is beneficial to improving the above properties.

The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims (9)

1. The acidizing corrosion inhibitor for oil and gas well fracturing is characterized by comprising the following components in percentage by weight: 0.3 to 0.6 weight percent of o-methoxybenzaldehyde modified meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole, 0.8 to 1.2 weight percent of amphoteric organic ion salt, 0.1 to 0.4 weight percent of diazolidinyl urea, 1 to 3 weight percent of hydroxypropyl trimethyl ammonium chloride chitosan, 1 to 3 weight percent of bis (2-hydroxyethyl) amino (trimethylol) methane, 0.2 to 0.4 weight percent of lauryl hydroxyethyl imidazoline, 0.8 to 1.2 weight percent of urotropine, 0.1 to 1 weight percent of nonionic fluorocarbon surfactant, 4 to 8 weight percent of dodecyl trimethyl ammonium chloride, 8 to 25 weight percent of APG 1214 surfactant, 3 to 5 weight percent of cosolvent and the balance of water.

2. The acidizing corrosion inhibitor for oil and gas well fracturing according to claim 1, wherein the preparation method of o-methoxybenzaldehyde modified meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole comprises the following steps: under the protection of inert gas, adding the meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole into a three-port reaction bottle, adding absolute ethyl alcohol with the mass 3-5 times of that of the meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole, uniformly stirring, slowly dropwise adding absolute ethyl alcohol solution of o-methoxybenzaldehyde while stirring, dropwise adding the absolute ethyl alcohol solution within 1 hour, continuously stirring at 65-90 ℃ for reaction for 3-5 hours after dropwise adding, cooling, suction filtering to obtain a filter cake, recrystallizing the filter cake with absolute ethyl alcohol for 3-5 times, and vacuum drying to obtain the o-methoxybenzaldehyde modified meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole.

3. The acidizing corrosion inhibitor for oil and gas well fracturing according to claim 2, wherein the inert gas is any one of nitrogen, helium, neon and argon.

4. The acidizing corrosion inhibitor for oil and gas well fracturing according to claim 2, wherein the molar ratio of meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole to o-methoxybenzaldehyde is 1:4.

5. The acidizing corrosion inhibitor for oil and gas well fracturing according to claim 2, wherein the mass percentage concentration of the absolute ethanol solution of o-methoxybenzaldehyde is 5-10 wt%.

6. The acidizing corrosion inhibitor for oil and gas well fracturing according to claim 1, wherein the amphoteric organic ion salt is at least one of pyridinium hydroxy propane sulfonate and 1-benzyl pyridine-3-carboxylate; the hydroxypropyl trimethyl ammonium chloride chitosan has a number average molecular weight of 10 ten thousand and a substitution degree of 90%.

7. The acidizing corrosion inhibitor for oil and gas well fracturing according to claim 1, wherein the nonionic fluorocarbon surfactant is a fluorocarbon surfactant of model ZY-FC 368.

8. The acidizing corrosion inhibitor for oil and gas well fracturing according to claim 1, wherein the cosolvent is at least one of ethanol and methanol.

9. A method of preparing an acidizing corrosion inhibitor for oil and gas well fracturing according to any one of claims 1 to 8, comprising the steps of: and uniformly mixing the components according to the weight percentage, vacuumizing, defoaming, and naturally standing for 1-3 hours to prepare the acidizing corrosion inhibitor for oil and gas well fracturing.