A high-temperature acidizing corrosion inhibitor for oil fields, its preparation method and application

Abstract

The present invention relates to the technical field of corrosion inhibitors, and discloses a high-temperature acidizing corrosion inhibitor for oil fields, its preparation method and application. The present invention uses (S)-1-amino-3-chloro-2-propanol hydrochloride, aldehyde group compounds such as terephthalaldehyde, succinic anhydride, quinoline, etc. as raw materials, and through Schiff base, acid anhydride esterification and quaternization reactions, a new type of high-temperature acidizing corrosion inhibitor for oil fields is prepared. The corrosion inhibitor of the present invention contains multiple betaine groups, which can form strong coordination complex and other interactions with steel sheets, enabling the corrosion inhibitor to adhere well to the surface of steel sheets, forming a stable organic small molecule hydrophobic film, inhibiting the contact between corrosion inhibitor media such as hydrochloric acid and the surface of steel sheets, and playing an excellent corrosion inhibition role. And this corrosion inhibitor contains multiple benzene rings, biphenyl, quinoline and other structures, has good thermal stability, and has good practical applications in the anti-corrosion and corrosion inhibition of equipment such as oil pipes in oil field exploitation and high-temperature wells.

Description

Technical Field

[0001] The present invention relates to the technical field of corrosion inhibitors, and specifically to a high-temperature acidizing corrosion inhibitor for oil fields, its preparation method and application. Background Technique

[0002] During the exploitation of oil and gas wells, the fracturing acidizing technology is an effective method to increase the production of oil and gas. During the fracturing acidizing construction process, due to the injection of a large amount of acid solution, corrosion will occur to the metal pipes of oil and gas wells and downhole metals and other equipment. In order to reduce the corrosion of acid solution to the metal equipment of oil and gas wells, it is necessary to add a corrosion inhibitor to the fracturing acid solution.

[0003] Currently, the acidizing corrosion inhibitors for oil fields mainly include imidazoline, triazole, quaternary ammonium salt, etc. Among them, betaine corrosion inhibitor is an amphoteric surfactant with excellent performance, having good anti-corrosion and corrosion inhibition, and is widely used in oil field exploitation, metal anti-corrosion, etc. Patent CN111137991 B discloses a corrosion and scale inhibition bactericide and its application, a corrosion and scale inhibition bactericide composed of a betaine-type amphoteric surfactant, cetyl dimethyl (2-sulfite) ethyl ammonium and a lignin derivative, having good corrosion inhibition, scale removal and antibacterial properties. However, the corrosion and scale inhibition bactericide of this patent does not show good high-temperature resistance and cannot meet the actual application of corrosion inhibitors in high-temperature reservoir exploitation and other aspects. Summary of the Invention

[0004] The technical problem solved by the present invention is: to provide a high-temperature acidizing corrosion inhibitor for oil fields with good temperature resistance and high anti-corrosion and corrosion inhibition performance.

[0005] Technical Solution: A high-temperature acidizing corrosion inhibitor for oil fields includes the following structural formula;

[0006]

[0007] Furthermore, the preparation method of the high-temperature acidizing corrosion inhibitor for oil fields includes:

[0008] (1). Add ethanol, (S)-1-amino-3-chloro-2-propanol hydrochloride, and sodium hydroxide to a container, stir and then add an aldehyde compound, stir and react at 50-65 °C for 6-10 h, add water for dilution, extract with ethyl acetate, dry the organic phase with anhydrous sodium sulfate, filter and then distill under reduced pressure, dissolve the product in ethanol, and perform recrystallization to obtain intermediate A.

[0009] (2), Add tetrahydrofuran, intermediate A, succinic anhydride, and 4-dimethylaminopyridine into a container, stir and react at 40 - 50 °C for 18 - 24 h, add water and sodium hydroxide, adjust the pH to 9 - 10, add saturated sodium chloride solution, extract with ethyl acetate, dry the organic phase with anhydrous sodium sulfate, filter and then distill under reduced pressure. Dissolve the product in an ethanol aqueous solution and perform recrystallization to obtain intermediate B.

[0010] (3), Add ethanol, intermediate B, and quinoline into a container, stir and react at 75 - 80 °C for 36 - 48 h, distill under reduced pressure. Dissolve the product in an ethanol aqueous solution and perform recrystallization to obtain a high-temperature acidizing corrosion inhibitor for oil fields.

[0011] Furthermore, in (1), the molar ratio of (S)-1-amino-3-chloro-2-propanol hydrochloride, sodium hydroxide, and aldehyde compound is (2 - 3.3):(2 - 3.3):1.

[0012] Furthermore, the aldehyde compound is terephthalaldehyde, 4,4'-biphenyldialdehyde, or benzene-1,3,5-tricarbaldehyde.

[0013] Furthermore, in (2), the molar ratio of intermediate A, succinic anhydride, and 4-dimethylaminopyridine is 1:(2.4 - 3.6):(0.12 - 0.16).

[0014] Furthermore, in (3), the molar ratio of intermediate B and quinoline is 1:(2.4 - 3.6).

[0015] Furthermore, the application of the high-temperature acidizing corrosion inhibitor for oil fields in oil field anti-corrosion and corrosion inhibition.

[0016] The technical effects of the present invention are as follows: The present invention uses (S)-1-amino-3-chloro-2-propanol hydrochloride, aldehyde compounds such as terephthalaldehyde, succinic anhydride, quinoline, etc. as raw materials, and prepares a new type of high-temperature acidizing corrosion inhibitor for oil fields through Schiff base, acid anhydride esterification, and quaternization reactions.

[0017] The corrosion inhibitor of the present invention contains multiple betaine groups, which can form strong coordination complex and other interactions with the steel sheet, enabling the corrosion inhibitor to adhere well to the surface of the steel sheet, form a stable organic small molecule hydrophobic film, inhibit the contact between corrosion inhibitor media such as hydrochloric acid and the surface of the steel sheet, and play an excellent corrosion inhibition role. And this corrosion inhibitor contains multiple benzene rings, biphenyl, quinoline and other structures, has good thermal stability, the corrosion inhibitor will not undergo thermal decomposition at high temperatures, enabling the corrosion inhibitor to still maintain good structural stability, and the corrosion inhibition efficiency decreases very little, with excellent anti-corrosion and corrosion inhibition performance. It has good practical applications in the anti-corrosion and corrosion inhibition of oil field exploitation, tubing and other equipment in high-temperature wells. Specific embodiments

[0018] To make the technical solutions and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below.

[0019] Example 1

[0020] (1) Add 30 mL of ethanol, 20 mmol of (S)-1-amino-3-chloro-2-propanol hydrochloride (CAS No. 34839-13-9), and 20 mmol of sodium hydroxide to a container. After stirring, add 10 mmol of terephthalaldehyde, stir and react at 65 °C for 6 h, add water for dilution, extract with ethyl acetate, dry the organic phase with anhydrous sodium sulfate, filter, and then distill under reduced pressure. The product is dissolved in ethanol and recrystallized to obtain intermediate A. The reaction formula is:

[0021]

[0022] (2) Add 40 mL of tetrahydrofuran, 10 mmol of intermediate A, 24 mmol of succinic anhydride, and 1.2 mmol of 4-dimethylaminopyridine to a container. Stir and react at 40 °C for 24 h, add 20 mL of water and sodium hydroxide, adjust the pH to 9, add saturated sodium chloride solution, extract with ethyl acetate, dry the organic phase with anhydrous sodium sulfate, filter, and then distill under reduced pressure. The product is dissolved in an ethanol aqueous solution and recrystallized to obtain intermediate B. The reaction formula is:

[0023]

[0024] (3) Add 20 mL of ethanol, 20 mmol of intermediate B, and 48 mmol of quinoline to a container. Stir and react at 75 °C for 48 h, distill under reduced pressure, dissolve the product in an ethanol aqueous solution, and recrystallize to obtain a high-temperature acidification inhibitor for oil fields. The reaction formula is:

[0025]

[0026] Example 2

[0027] (1) Add 40 mL of ethanol, 20 mmol of (S)-1-amino-3-chloro-2-propanol hydrochloride, and 20 mmol of sodium hydroxide to a container. After stirring, add 10 mmol of 4,4'-biphenyldicarboxaldehyde, stir and react at 60 °C for 8 h, add water for dilution, extract with ethyl acetate, dry the organic phase with anhydrous sodium sulfate, filter, and then distill under reduced pressure. The product is dissolved in ethanol and recrystallized to obtain intermediate A. The structural formula is:

[0028]

[0029] (2) Add 60 mL of tetrahydrofuran, 10 mmol of intermediate A, 24 mmol of succinic anhydride, and 1.2 mmol of 4-dimethylaminopyridine into a container. Stir and react at 50 °C for 24 h. Add 20 mL of water and sodium hydroxide to adjust the pH to 9. Add saturated sodium chloride solution and extract with ethyl acetate. Dry the organic phase with anhydrous sodium sulfate, filter, and then distill under reduced pressure. Dissolve the product in an ethanol aqueous solution and perform recrystallization to obtain intermediate B. The structural formula is:

[0030] (3) Add 30 mL of ethanol, 20 mmol of intermediate B, and 48 mmol of quinoline into a container. Stir and react at 80 °C for 36 h. Distill under reduced pressure. Dissolve the product in an ethanol aqueous solution and perform recrystallization to obtain a high-temperature acidizing corrosion inhibitor for oil fields. The structural formula is:

[0031] Example 3

[0032] (1) Add 40 mL of ethanol, 33 mmol of (S)-1-amino-3-chloro-2-propanol hydrochloride, and 33 mmol of sodium hydroxide into a container. After stirring, add 10 mmol of benzene-1,3,5-tricarbaldehyde. Stir and react at 50 °C for 10 h. Add water for dilution and extract with ethyl acetate. Dry the organic phase with anhydrous sodium sulfate, filter, and then distill under reduced pressure. Dissolve the product in ethanol and perform recrystallization to obtain intermediate A. The structural formula is:

[0033]

[0034] (2) Add 60 mL of tetrahydrofuran, 10 mmol of intermediate A, 36 mmol of succinic anhydride, and 1.6 mmol of 4-dimethylaminopyridine into a container. Stir and react at 50 °C for 24 h. Add 20 mL of water and sodium hydroxide to adjust the pH to 10. Add saturated sodium chloride solution and extract with ethyl acetate. Dry the organic phase with anhydrous sodium sulfate, filter, and then distill under reduced pressure. Dissolve the product in an ethanol aqueous solution and perform recrystallization to obtain intermediate B. The structural formula is:

[0035] (3) Add 30 mL of ethanol, 20 mmol of intermediate B, and 72 mmol of quinoline into a container. Stir and react at 80 °C for 48 h. Distill under reduced pressure. Dissolve the product in an ethanol aqueous solution and perform recrystallization to obtain a high-temperature acidizing corrosion inhibitor for oil fields. The structural formula is:

[0036] Comparative Example 1 Use the intermediate B prepared in Example 1 as a corrosion inhibitor.

[0037] Comparative Example 2 Use the intermediate B prepared in Example 2 As a corrosion inhibitor.

[0038] Comparative Example 3 used Intermediate B prepared in Example 3 As a corrosion inhibitor.

[0039] Comparative Example 4

[0040] (1) Add 30 mL of ethanol, 10 mmol of (S)-1-amino-3-chloro-2-propanol hydrochloride, and 20 mmol of sodium hydroxide to a container. After stirring, add 10 mmol of phthalaldehyde, stir and react at 65 °C for 6 h, add water for dilution, extract with ethyl acetate, dry the organic phase with anhydrous sodium sulfate, filter, and then distill under reduced pressure. Dissolve the product in ethanol and perform recrystallization to obtain Intermediate A. The structural formula is:

[0041]

[0042] (2) Add 40 mL of tetrahydrofuran, 10 mmol of Intermediate A, 12 mmol of succinic anhydride, and 1.2 mmol of 4-dimethylaminopyridine to a container. Stir and react at 40 °C for 24 h, add 20 mL of water and sodium hydroxide, adjust the pH to 9, add saturated sodium chloride solution, extract with ethyl acetate, dry the organic phase with anhydrous sodium sulfate, filter, and then distill under reduced pressure. Dissolve the product in an ethanol aqueous solution and perform recrystallization to obtain Intermediate B. The structural formula is:

[0043] (3) Add 20 mL of ethanol, 20 mmol of Intermediate B, and 24 mmol of quinoline to a container. Stir and react at 75 °C for 48 h, distill under reduced pressure, dissolve the product in an ethanol aqueous solution, and perform recrystallization to obtain the corrosion inhibitor. The structural formula is:

[0044] According to SY / T 5405-1996 "Test Methods and Evaluation Indexes for Acidizing Corrosion Inhibitors", test the anti-corrosion and corrosion inhibition performance of the corrosion inhibitor. The test sample is an N80 steel sheet. Before the test, polish the N80 steel sheet, clean it to remove oil, and dry it. The corrosion medium is a hydrochloric acid solution with a mass fraction of 20%. The mass fraction of the corrosion inhibitor in the corrosion medium is 3%. The test temperature is 25 - 150 °C, and a condenser reflux tube is installed during the test. Calculate the corrosion rate V and the corrosion inhibition efficiency n after corrosion.

[0045] V = (M - M1) / (S×t); M is the initial mass of the N80 steel sheet sample, M1 is the mass of the N80 steel sheet after corrosion and removal of corrosion products. S is the surface area of the N80 steel sheet sample. s is the corrosion time.

[0046] n = (V1 - V0) / V0 × 100%. V1 is the corrosion rate when the corrosion inhibitor is added. V0 is the corrosion rate without the corrosion inhibitor.

[0047] Table 1 Corrosion Inhibition Efficiency Test of Corrosion Inhibitor

[0048]

[0049] After testing, the high-temperature acidizing corrosion inhibitors prepared in Examples 1 - 3 have a corrosion inhibition efficiency of 92.0 - 99.3% at room temperature of 25°C, and also reach 85.7 - 94.4% at high temperature of 150°C. This is mainly because the corrosion inhibitor contains multiple betaine groups, which can form strong coordination complexation and other interactions with the steel sheet, with a large binding ability and strong adsorption performance, enabling the corrosion inhibitor to adhere well to the surface of the steel sheet, forming a stable organic small molecule hydrophobic film, inhibiting the contact between corrosion inhibitor media such as hydrochloric acid and the surface of the steel sheet, and playing an excellent corrosion inhibition role. And this corrosion inhibitor contains multiple benzene rings, biphenyl, quinoline and other structures, with good thermal stability. The corrosion inhibitor will not undergo thermal decomposition at high temperature, enabling the corrosion inhibitor to still maintain good structural stability, with a very small decrease in corrosion inhibition efficiency and excellent anti-corrosion and corrosion inhibition performance.

[0050] In Comparative Examples 1, 2, and 3, Intermediate B is used as the corrosion inhibitor, which does not contain betaine groups, has poor coordination complexation and other interactions with the surface of the steel sheet, and is difficult to form a stable organic small molecule hydrophobic film on the surface of the steel sheet, resulting in a very low corrosion inhibition efficiency.

[0051] The corrosion inhibitor in Comparative Example 4 only contains one betaine group, has poor coordination complexation and other interactions with the surface of the steel sheet, and has a relatively low corrosion inhibition efficiency.

[0052] The above has described a specific embodiment of the present invention in detail, but the content described is only a preferred embodiment of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the application of the present invention should still fall within the scope covered by the patent of the present invention.

Claims

1. A high-temperature acidizing corrosion inhibitor for oil fields, characterized in that, The high-temperature acidizing corrosion inhibitor for oil fields has the following structural formula; ； ； 。 2. A preparation method of a high-temperature acidizing corrosion inhibitor for oil fields as described in claim 1, characterized in that, The preparation method includes: (1) Add ethanol, (S)-1-amino-3-chloro-2-propanol hydrochloride, and sodium hydroxide into a container. After stirring, add the aldehyde compound, stir and react, add water for dilution, extract with ethyl acetate, and perform recrystallization to obtain intermediate A; The structural formula of the intermediate A is , or ; (2) Add tetrahydrofuran, intermediate A, succinic anhydride, and 4-dimethylaminopyridine to a container, stir and react, add water and sodium hydroxide to adjust the pH to 9-10, add saturated sodium chloride solution, extract with ethyl acetate, and perform recrystallization to obtain intermediate B; the structural formula of the intermediate B is 、 or ; (3) Add ethanol, intermediate B, and quinoline into a container, stir and react, perform vacuum distillation, and perform recrystallization to obtain the high-temperature acidizing corrosion inhibitor for oil fields; The aldehyde compound is terephthalaldehyde, 4,4'-biphenyldialdehyde, or benzene-1,3,5-tricarbaldehyde.

3. The preparation method of the high-temperature acidizing corrosion inhibitor for oil fields according to claim 2, wherein, In the step (1), the molar ratio of (S)-1-amino-3-chloro-2-propanol hydrochloride, sodium hydroxide, and the aldehyde compound is (2 - 3.3):(2 - 3.3):

1.

4. The preparation method of the high-temperature acidizing corrosion inhibitor for oil fields according to claim 2, characterized in that, In the step (1), the reaction is carried out at 50 - 65 °C for 6 - 10 h.

5. The preparation method of the high-temperature acidizing corrosion inhibitor for oil fields according to claim 2, characterized in that, In the step (2), the molar ratio of intermediate A, succinic anhydride, and 4-dimethylaminopyridine is 1:(2.4 - 3.6):(0.12 - 0.16).

6. The preparation method of the high-temperature acidizing corrosion inhibitor for oil fields according to claim 2, characterized in that, In the step (2), the reaction is carried out at 40 - 50 °C for 18 - 24 h.

7. The preparation method of the high-temperature acidizing corrosion inhibitor for oil fields according to claim 2, characterized in that, In the step (3), the molar ratio of intermediate B and quinoline is 1:(2.4 - 3.6).

8. The preparation method of the high-temperature acidizing corrosion inhibitor for oil fields according to claim 2, characterized in that In the step (3), the reaction is carried out at 75 - 80 °C for 36 - 48 h.

9. Application of the high-temperature acidizing corrosion inhibitor for oil fields as described in claim 1 in oil field anti-corrosion and corrosion inhibition.

Images