High-temperature acidizing corrosion inhibitor as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of oil exploitation, and particularly relates to a high-temperature acidizing corrosion inhibitor and a preparation method and application thereof. The preparation method comprises the following steps: sequentially adding 1-aza-18-crown ether-6, methanol, a reducing agent and benzaldehyde-2, 4-sodium disulfonate into a reactor, uniformly stirring, adjusting the pH value to 2-3 by using hydrochloric acid, heating, and carrying out heat preservation reaction; 2, 3-dimethoxybenzyl chloride is added into the reactor, sodium hydroxide is used for adjusting the pH to be 8-9, heating reflux and reduced pressure distillation are carried out to obtain a viscous solid, cyclohexane is used for recrystallization to obtain a solid, the solid is dried overnight at 105 DEG C, and the product high-temperature acidizing corrosion inhibitor is obtained. Based on 1 mole part of the 1-aza-18-crown ether-6, the dosage of the benzaldehyde-2, 4-sodium disulfonate is 0.8-1.2 mole parts, and the dosage of the 2, 3-dimethoxy benzyl chloride is 0.8-1.2 mole parts, and the dosage of the 2, 3-dimethoxy benzyl chloride is 0.8-1.2 mole parts. The acidizing corrosion inhibitor has the advantages of high temperature resistance and good corrosion inhibition effect.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum extraction, and in particular relates to a high-temperature acidizing corrosion inhibitor and a preparation method and application thereof. Background Art

[0002] In the process of oil and gas well exploitation, fracturing and acidizing technology is a very effective measure to increase production. Its principle is to inject acid fracturing fluid into the formation through the oil well tubing. The acid fracturing fluid reacts with the limestone and other components in the formation to generate soluble substances. At the same time, under the action of high pressure, the porosity of the formation is increased. When the soluble substances are discharged from the formation with the acid, the permeability of the oil-producing layer is improved, thereby achieving the purpose of increasing production.

[0003] In this process, the acid used mainly includes strong acids such as hydrochloric acid and hydrofluoric acid. The corrosion of acid on metal will not only damage the ground equipment and downhole pipelines, but also the large amount of corroded iron ions will form iron oxide precipitation under certain conditions, affecting the acidizing effect. Sometimes it may also lead to reduced strength and thinning of the wall thickness of the equipment, which may eventually cause perforation and rupture of the equipment, causing serious economic losses. Therefore, adding corrosion inhibitors to the acid fracturing fluid is a necessary anti-corrosion measure.

[0004] Acidizing corrosion inhibitor is a chemical substance or a mixture of several chemical substances that exists in the environment in an appropriate concentration and form and can prevent or slow down corrosion. It can minimize the corrosion of acid on equipment, extend the life of pipelines, and ensure the smooth progress of acidizing construction. The quality of acidizing corrosion inhibitor is related to the success or failure of acidizing construction.

[0005] CN104449653A discloses an acidified corrosion inhibitor and its preparation and application; according to the composition by weight: add 23-25 ​​parts of ketone, 24-26 parts of aldehyde and 9-11 parts of acid to the reactor in sequence, adjust the pH of the reaction liquid system to 4, start the agitator, gradually heat up to 100°C, keep constant temperature for 30 minutes, add 6-21 parts of alcoholamine to the reactor, keep constant temperature at 100°C for 2 hours, wait for the material to cool, add 35-37 parts of alcohol, remove from the reactor, and obtain the product. However, the corrosion inhibitor has complex components, and the product is Mannich base, which has poor water solubility, so a large amount of ethanol is added as a solvent, which increases the cost, and ethanol is flammable and volatile, and its vapor can form an explosive mixture with air.

[0006] CN113278409B discloses a high temperature acidification corrosion inhibitor, which belongs to the field of oil and gas field mining anti-corrosion technology. The corrosion inhibitor includes a corrosion inhibitor main agent, an auxiliary agent A and an auxiliary agent B. The mass ratio of the corrosion inhibitor main agent, the auxiliary agent A and the auxiliary agent B is 10:3:1. The corrosion inhibitor main agent, the auxiliary agent A and the auxiliary agent B are mixed to form a corrosion inhibitor, and ethanol is used to dissolve the corrosion inhibitor solution. The preparation method of the corrosion inhibitor main agent is: cyanoguanidine, 4-(((4-chloropyridin-2-yl)oxy)methyl)benzonitrile and potassium hydroxide are reacted in a solvent ethylene glycol monoethyl ether at 120°C for 2 hours to generate a product 6-(4-(((4-chloropyridin-2-yl)oxy)methyl)benzonitrile)1,3,5-triazine-2,4, diamine, which is the corrosion inhibitor main agent. Auxiliary agent B is made by reacting the raw materials N, N-dimethylamine and oxalic acid at a temperature of 90°C for 6 hours in the presence of a catalyst. However, the invention adds 5wt% corrosion inhibitor to 20wt% hydrochloric acid solution at 180℃, and the corrosion rate is greater than 50g / (m 2 h), the corrosion inhibition effect needs to be improved. Summary of the invention

[0007] The present invention aims at the above-mentioned deficiencies of the prior art and provides a high temperature acidizing corrosion inhibitor and a preparation method and application thereof. The acidizing corrosion inhibitor of the present invention has the advantages of high temperature resistance and good corrosion inhibition effect.

[0008] In order to achieve the above objectives:

[0009] In a first aspect, the present invention discloses a method for preparing a high temperature acidizing corrosion inhibitor, and the specific steps of the preparation method are as follows:

[0010] (1) adding 1-aza-18-crown-6, methanol, a reducing agent, and sodium benzaldehyde-2,4-disulfonate to a reactor in sequence, stirring evenly, adjusting the pH to 2-3 with hydrochloric acid, and heating and keeping the reaction;

[0011] (2) Add 2,3-dimethoxybenzyl chloride to the above reactor, adjust the pH to 8-9 with sodium hydroxide, heat to reflux, and distill under reduced pressure to obtain a viscous solid, which is recrystallized with cyclohexane to obtain a solid, and dried at 105° C. overnight to obtain a high-temperature acidified corrosion inhibitor product.

[0012] In the present invention, preferably, based on 1 mole of 1-aza-18-crown-6, the amounts of sodium benzaldehyde-2,4-disulfonate and 2,3-dimethoxybenzyl chloride are 0.8-1.2 and 0.8-1.2 mole parts, respectively.

[0013] More preferably, based on 1 mole of 1-aza-18-crown-6, the amounts of sodium benzaldehyde-2,4-disulfonate and 2,3-dimethoxybenzyl chloride are 0.9-1.1 and 0.9-1.1 mole parts, respectively.

[0014] In the present invention, preferably, the mass ratio of methanol to 1-aza-18-crown-6 in step (1) is 20-30:1.

[0015] In the present invention, preferably, the reducing agent in step (1) is one of sodium borohydride, sodium triacetoxyborohydride and sodium cyanoborohydride.

[0016] More preferably, the reducing agent is one of sodium triacetoxyborohydride and sodium cyanoborohydride.

[0017] In the present invention, preferably, the mass ratio of the reducing agent to 1-aza-18-crown ether-6 is 0.2-0.8:1.

[0018] In the present invention, preferably, the temperature of the heating and heat preservation reaction in step (1) is 50-60° C. and the time is 1-4 h.

[0019] In the present invention, preferably, the heating reflux time in step (2) is 12-48h.

[0020] The reaction equation for the synthesis of the high temperature acidification corrosion inhibitor of the present invention is as follows:

[0021]

[0022] In another aspect, the present invention discloses a high temperature acidizing corrosion inhibitor, wherein the molecular structure of the acidizing corrosion inhibitor is as follows:

[0023]

[0024] The third object of the present invention is to disclose the application of the above-mentioned high temperature acidizing corrosion inhibitor in oil field acidizing fracturing.

[0025] The high temperature acidification corrosion inhibitor molecule of the present invention contains quaternary ammonium salt, which has strong positive charge and can be adsorbed on the metal surface, so that the whole molecule forms a protective film on the metal surface. The 2,3-dimethoxybenzyl group is a hydrophobic structure, which can slow down the approach of the acidic water phase to the metal surface; the crown ether can encapsulate the iron ions, so that the iron ions generated by corrosion cannot flow away with the acid solution, thereby preventing further corrosion. The S and O of the sulfonic acid group have lone pairs of electrons, which can be adsorbed on the metal surface through various ways such as electrostatic adsorption and the formation of coordination bonds, forming a more solid protective film.

[0026] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0027] (1) The high temperature acidification corrosion inhibitor of the present invention is suitable for different temperature ranges and has good corrosion inhibition effect from 60-180°C;

[0028] (2) The high temperature acidification corrosion inhibitor of the present invention has a good corrosion inhibition effect. When 5 wt % of the corrosion inhibitor is added to a 20 wt % hydrochloric acid solution at 180°C, the corrosion rate is less than 15 g / (m 2 ·h); When 6wt% of corrosion inhibitor is added to 12wt% hydrochloric acid + 3wt% hydrofluoric acid solution at 180℃, the corrosion rate is less than 22g / (m 2 h). DETAILED DESCRIPTION

[0029] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0030] The present invention will be further described below in conjunction with specific embodiments:

[0031] Example 1

[0032] (1) Add 20 mmol of 1-aza-18-crown ether-6, 105.2 g of methanol, 1.05 g of sodium borohydride, and 16 mmol of sodium benzaldehyde-2,4-disulfonate into a reactor in sequence, stir evenly, adjust the pH to 2-3 with hydrochloric acid, heat to 50°C, and keep the reaction warm for 2 h.

[0033] (2) Add 16 mmol 2,3-dimethoxybenzyl chloride to the above reactor, adjust the pH to 8-9 with sodium hydroxide, heat and reflux for 12 hours, and distill under reduced pressure to obtain a viscous solid, which is recrystallized with cyclohexane to obtain a solid, and dried at 105° C. overnight to obtain a high-temperature acidified corrosion inhibitor product.

[0034] Example 2

[0035] (1) Add 20 mmol of 1-aza-18-crown ether-6, 107 g of methanol, 1.83 g of sodium borohydride, and 24 mmol of sodium benzaldehyde-2,4-disulfonate into a reactor in sequence, stir evenly, adjust the pH to 2-3 with hydrochloric acid, heat to 55°C, and keep the reaction warm for 3 hours.

[0036] (2) Add 17 mmol 2,3-dimethoxybenzyl chloride to the above reactor, adjust the pH to 8-9 with sodium hydroxide, heat and reflux for 24 hours, and distill under reduced pressure to obtain a viscous solid, which is recrystallized with cyclohexane to obtain a solid, and dried at 105° C. overnight to obtain a high-temperature acidified corrosion inhibitor.

[0037] Example 3

[0038] (1) Add 20 mmol of 1-aza-18-crown ether-6, 118 g of methanol, 1.96 g of sodium borohydride, and 17 mmol of sodium benzaldehyde-2,4-disulfonate into a reactor in sequence, stir evenly, adjust the pH to 2-3 with hydrochloric acid, heat to 60°C, and keep the temperature for reaction for 1 hour.

[0039] (2) Add 24 mmol 2,3-dimethoxybenzyl chloride to the above reactor, adjust the pH to 8-9 with sodium hydroxide, heat and reflux for 32 hours, and distill under reduced pressure to obtain a viscous solid, which is recrystallized with cyclohexane to obtain a solid, and dried at 105° C. overnight to obtain a high-temperature acidified corrosion inhibitor product.

[0040] Example 4

[0041] (1) Add 20 mmol of 1-aza-18-crown ether-6, 152 g of methanol, 2.14 g of sodium borohydride, and 23 mmol of sodium benzaldehyde-2,4-disulfonate into a reactor in sequence, stir evenly, adjust the pH to 2-3 with hydrochloric acid, heat to 52°C, and keep the reaction warm for 4 hours.

[0042] (2) Add 18 mmol of 2,3-dimethoxybenzyl chloride to the above reactor, adjust the pH to 8-9 with sodium hydroxide, heat and reflux for 36 hours, and distill under reduced pressure to obtain a viscous solid. Recrystallize with cyclohexane to obtain a solid, and dry at 105° C. overnight to obtain a high-temperature acidified corrosion inhibitor product.

[0043] Example 5

[0044] (1) Add 20 mmol of 1-aza-18-crown ether-6, 157.8 g of methanol, 3.33 g of sodium triacetoxyborohydride, and 16 mmol of sodium benzaldehyde-2,4-disulfonate into a reactor in sequence, stir evenly, adjust the pH to 2-3 with hydrochloric acid, heat to 55°C, and keep the temperature for 2 hours.

[0045] (2) Add 22 mmol of 2,3-dimethoxybenzyl chloride to the above reactor, adjust the pH to 8-9 with sodium hydroxide, heat and reflux for 18 hours, and distill under reduced pressure to obtain a viscous solid. Recrystallize with cyclohexane to obtain a solid, and dry at 105° C. overnight to obtain a high-temperature acidified corrosion inhibitor product.

[0046] Example 6

[0047] (1) Add 20 mmol of 1-aza-18-crown ether-6, 144 g of methanol, 4.21 g of sodium triacetoxyborohydride, and 21 mmol of sodium benzaldehyde-2,4-disulfonate into a reactor in sequence, stir evenly, adjust the pH to 2-3 with hydrochloric acid, heat to 60°C, and keep the temperature for reaction for 2 h.

[0048] (2) Add 19 mmol 2,3-dimethoxybenzyl chloride to the above reactor, adjust the pH to 8-9 with sodium hydroxide, heat and reflux for 42 hours, and distill under reduced pressure to obtain a viscous solid, which is recrystallized with cyclohexane to obtain a solid, and dried at 105° C. overnight to obtain a high-temperature acidified corrosion inhibitor product.

[0049] Example 7

[0050] (1) Add 20 mmol of 1-aza-18-crown ether-6, 125 g of methanol, 3.3 g of sodium cyanoborohydride, and 19 mmol of sodium benzaldehyde-2,4-disulfonate into a reactor in sequence, stir evenly, adjust the pH to 2-3 with hydrochloric acid, heat to 55°C, and keep the reaction warm for 4 hours.

[0051] (2) Add 20 mmol of 2,3-dimethoxybenzyl chloride to the above reactor, adjust the pH to 8-9 with sodium hydroxide, heat and reflux for 45 hours, and distill under reduced pressure to obtain a viscous solid, which is recrystallized with cyclohexane to obtain a solid, and dried at 105° C. overnight to obtain a high-temperature acidified corrosion inhibitor product.

[0052] Example 8

[0053] (1) Add 20 mmol of 1-aza-18-crown ether-6, 135 g of methanol, 3.4 g of sodium cyanoborohydride, and 20 mmol of sodium benzaldehyde-2,4-disulfonate into a reactor in sequence, stir evenly, adjust the pH to 2-3 with hydrochloric acid, heat to 60°C, and keep the temperature for reaction for 3 hours.

[0054] (2) Add 21 mmol of 2,3-dimethoxybenzyl chloride to the above reactor, adjust the pH to 8-9 with sodium hydroxide, heat and reflux for 48 hours, and distill under reduced pressure to obtain a viscous solid. Recrystallize with cyclohexane to obtain a solid, and dry at 105° C. overnight to obtain a high-temperature acidified corrosion inhibitor.

[0055] Example 9 Corrosion Rate Test

[0056] The static corrosion rate at normal pressure and the dynamic corrosion rate at high temperature and high pressure were determined with reference to the method in SY / T 5405-2019 “Performance Test Method and Evaluation Method of Corrosion Inhibitors for Acidification”. The different test parameters are shown in Tables 1 and 2, and the test results are shown in Table 3.

[0057] A comparative experiment was conducted using the acidified corrosion inhibitor HJ-1 from Shandong Juxin New Materials Co., Ltd.

[0058] Table 1 Conditions for determining static corrosion rate at normal pressure

[0059]

[0060] Table 2 High temperature and high pressure dynamic corrosion rate measurement conditions

[0061]

[0062] Table 3 Corrosion rate test results

[0063]

[0064] From Table 2 we can see that:

[0065] (1) When 5 wt% of corrosion inhibitor is added to 20 wt% hydrochloric acid solution at 180°C, the corrosion rate is less than 15 g / (m 2 ·h); while the corrosion rate of the acidified corrosion inhibitor HJ-1 of Shandong Juxin New Materials Co., Ltd. is 61g / (m 2 h), which is significantly higher than that of the present invention.

[0066] (2) When 6 wt% of corrosion inhibitor was added to 12 wt% hydrochloric acid + 3 wt% hydrofluoric acid solution at 180°C, the corrosion rate was less than 22 g / (m 2 ·h). The corrosion rate of the acidified corrosion inhibitor HJ-1 of Shandong Juxin New Materials Co., Ltd. is 66g / (m 2 h), which is significantly higher than that of the present invention.

[0067] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0068] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0069] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for preparing a high temperature acidification corrosion inhibitor, characterized in that: The specific steps of the preparation method are as follows: (1) adding 1-aza-18-crown-6, methanol, a reducing agent, and sodium benzaldehyde-2,4-disulfonate to a reactor in sequence, stirring evenly, adjusting the pH to 2-3 with hydrochloric acid, and heating and keeping the reaction; (2) Add 2,3-dimethoxybenzyl chloride to the above reactor, adjust the pH to 8-9 with sodium hydroxide, heat to reflux, and distill under reduced pressure to obtain a viscous solid, recrystallize with cyclohexane to obtain a solid, and dry at 105° C. overnight to obtain a product high-temperature acidification corrosion inhibitor; In the present invention, preferably, based on 1 mole of 1-aza-18-crown-6, the amounts of sodium benzaldehyde-2,4-disulfonate and 2,3-dimethoxybenzyl chloride are 0.8-1.2 and 0.8-1.2 mole parts, respectively.

2. The method for preparing a high temperature acidification corrosion inhibitor according to claim 1, characterized in that: Based on 1 mole of 1-aza-18-crown-6, the amounts of sodium benzaldehyde-2,4-disulfonate and 2,3-dimethoxybenzyl chloride are 0.9-1.1 and 0.9-1.1 mole parts respectively.

3. The method for preparing a high temperature acidification corrosion inhibitor according to claim 1, characterized in that: The mass ratio of methanol to 1-aza-18-crown ether-6 in step (1) is 20-30:

1.

4. The method for preparing a high temperature acidification corrosion inhibitor according to claim 1, characterized in that: The reducing agent described in step (1) is one of sodium borohydride, sodium triacetoxyborohydride and sodium cyanoborohydride.

5. The method for preparing a high temperature acidification corrosion inhibitor according to claim 1, characterized in that: The reducing agent is one of sodium triacetoxyborohydride and sodium cyanoborohydride.

6. The method for preparing a high temperature acidification corrosion inhibitor according to claim 1 or 4, characterized in that: The mass ratio of the reducing agent to 1-aza-18-crown ether-6 is 0.2-0.8:

1.

7. The method for preparing a high temperature acidification corrosion inhibitor according to claim 1, characterized in that: The temperature of the heating and heat preservation reaction in step (1) is 50-60° C. and the time is 1-4 hours.

8. The method for preparing a high temperature acidification corrosion inhibitor according to claim 1, characterized in that: The heating reflux time described in step (2) is 12-48h.

9. A high temperature acidification corrosion inhibitor, characterized in that: The molecular structural formula of the acidifying corrosion inhibitor is as follows:

10. Use of the high temperature acidizing corrosion inhibitor according to claim 9 in oil field acidizing fracturing.

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