Compound and titanium alloy high-temperature acidification corrosion inhibitor and application

Abstract

The application provides a compound and a high-temperature acidification corrosion inhibitor for titanium alloy and an application. The high-temperature acidification corrosion inhibitor for titanium alloy comprises a compound shown in formula I, a molybdate, a nitrate, an octylphenol polyoxyethylene ether and 2-methyl-3-butyn-2-ol in a mass ratio of 20-30:6-10:5-10:2-5:10-15, and the rest is a solvent; in the formula I, n is an integer of 6-12; the high-temperature acidification corrosion inhibitor for titanium alloy has a simple preparation method and a good high-temperature corrosion prevention effect.

Description

Technical Field

[0001] This invention belongs to the field of titanium alloy corrosion inhibitors, specifically relating to a compound and a high-temperature acidification corrosion inhibitor for titanium alloys and its application. Background Technology

[0002] In the field of oil and gas field development, titanium alloys are emerging materials. Their lightweight, high strength, excellent corrosion resistance, and high heat resistance have led to their widespread use in the automotive and aerospace industries. Titanium alloy tubing, casing, and drill pipes can completely replace nickel-based alloys and other special metal materials, becoming a key technology for oil production operations in harsh high-temperature and ultra-high-temperature environments, with broad application prospects. Under conditions such as humid atmospheres and seawater, titanium alloys exhibit far superior corrosion resistance compared to stainless steel, showing particularly strong resistance to pitting corrosion, acid corrosion, and stress corrosion. They also possess excellent resistance to alkalis, chlorides, chlorinated organic compounds, nitric acid, and sulfuric acid. However, titanium alloys have poor resistance to reducing oxygen, chromium salts, and hydrochloric acid, especially in high-temperature hydrochloric acid, where they corrode rapidly and are quickly consumed.

[0003] Corrosion inhibitors are one of the effective measures to control corrosion. CN116770310A describes the use of 80-90% solid phosphomolybdate and 10-20% sodium silicate to inhibit the corrosion of imported TC4 titanium alloy specimens in acid. At 140℃ and in 20% thickened acid, the lowest dynamic corrosion rate of the TC4 titanium alloy was 16.13 g / cm³. 2 However, solid phosphomolybdate is difficult to dissolve in hydrochloric acid, and the on-site acid preparation time is relatively long.

[0004] CN116180087A uses a dinitrobenzenemannish base, and in 20% pure hydrochloric acid at 25℃-100℃, reduces the corrosion rate of titanium alloy specimens to 10.86 g / cm³. 2 ·h.

[0005] CN117187814A uses precipitated salt, sodium polyepoxysuccinate, at 120℃ in 20% hydrochloric acid to control the static corrosion rate of titanium alloy to 1.15 g / cm³. 2 ·h.

[0006] Developing a high-temperature acidification corrosion inhibitor for titanium alloys that has stronger temperature resistance, better corrosion inhibition effect, and is convenient for on-site fracturing fluid preparation is an urgent problem to be solved in the field of corrosion inhibitors.

[0007] To better carry out acidizing operations, improve service capabilities, and promote the application of titanium alloy tubing in acidizing operations, it is of great significance to research and develop titanium alloy acidizing corrosion inhibitors suitable for high-temperature acidizing operations and improve the acidizing system. Summary of the Invention

[0008] To address the aforementioned problems, the present invention aims to provide a compound and a high-temperature acid corrosion inhibitor for titanium alloys, along with their applications. This high-temperature acid corrosion inhibitor for titanium alloys is simple to prepare and exhibits excellent high-temperature corrosion protection.

[0009] To achieve the above objectives, the present invention provides a compound having the structure shown in Formula I:

[0010]

[0011] In Equation I, n is an integer between 6 and 12.

[0012] The present invention also provides a method for preparing the compound represented by Formula I, which includes the following steps:

[0013] (1) Diethylenetriamine is subjected to an amidation reaction with a dicarboxylic acid compound, and then the temperature is raised to 200-220℃ for 6-8 hours to obtain an intermediate;

[0014] (2) The intermediate obtained in step (1) is reacted with chloroplatinic acid to prepare the compound shown in Formula I.

[0015] According to a specific embodiment of the present invention, preferably, in step (1), the temperature of the amidation reaction is 120-130°C.

[0016] According to a specific embodiment of the present invention, preferably, in step (1), the amidation reaction takes 4-6 hours.

[0017] According to a specific embodiment of the present invention, preferably, in step (1), the molar ratio of diethylenetriamine to dicarboxylic acid compound is 2.2-2.6:1.

[0018] According to a specific embodiment of the present invention, preferably, in step (2), the molar ratio of the intermediate to chloroplatinic acid is 1:2.0-2.4.

[0019] The present invention also provides a high-temperature acidification corrosion inhibitor for titanium alloys, the composition of which includes a compound of formula I in a mass ratio of 20-30:6-10:5-10:2-5:10-15, molybdate, nitrate, octylphenol polyoxyethylene ether, 2-methyl-3-butyn-2-ol, and the remainder being a solvent.

[0020] According to a specific embodiment of the present invention, preferably, the solvent is a polar solvent, more preferably, it includes one or a combination of two or more of water, methanol, and ethanol.

[0021] According to a specific embodiment of the present invention, preferably, in the titanium alloy high-temperature acidification corrosion inhibitor, the mass ratio of the compound represented by Formula I, molybdate, nitrate, octylphenol polyoxyethylene ether, 2-methyl-3-butyn-2-ol, and solvent is 20-30:6-10:5-10:2-5:10-15:30-57.

[0022] According to a specific embodiment of the present invention, preferably, the above-mentioned high-temperature acid corrosion inhibitor for titanium alloys is prepared by the following specific steps:

[0023] (1) Diethylenetriamine and diacid compounds (e.g., sebaceous acid) are subjected to an amidation reaction at 120-130℃ for 4-6 h, and then the temperature is raised to 200-220℃ for 6-8 h to obtain an intermediate. The molar ratio of diethylenetriamine to diacid compounds is 2.2-2.6:1.

[0024] (2) Then cool down to 100-120℃, add chloroplatinic acid, stir for 30-60 min, and after the reaction is complete, the compound shown in Formula I is obtained, with the molar ratio of chloroplatinic acid to intermediate being 2.0-2.4:1;

[0025] The reaction equation when n=8 in the product is used as an example. The reaction process is as follows:

[0026]

[0027] (3) Cool down to 50-60℃, add the compound shown in Formula I, molybdate, nitrate, octylphenol polyoxyethylene ether, 2-methyl-3-butyn-2-ol and solvent to obtain the high-temperature acidification corrosion inhibitor of the titanium alloy.

[0028] The present invention also provides the application of the above-mentioned titanium alloy high-temperature acidizing corrosion inhibitor in fracturing and acidizing operations, which includes the following steps: using the titanium alloy high-temperature acidizing corrosion inhibitor in fracturing and acidizing operations in oil and gas field development.

[0029] According to a specific embodiment of the present invention, preferably, the environment for the fracturing and acidizing operation in the oil and gas field development meets one or more of the following conditions:

[0030] (1) The temperature is 90-140℃;

[0031] (2) The hydrochloric acid concentration is 15-20 wt%;

[0032] (3) Pressure ≤ 16MPa;

[0033] (4) Rotation speed ≤ 60 rpm.

[0034] The high-temperature acidification corrosion inhibitor for titanium alloys of this invention has a simple preparation method and exhibits good anti-corrosion effect on titanium alloy steel sheets under harsh temperature and hydrochloric acid concentration conditions. Its corrosion inhibition performance and dissolution and dispersion performance meet the relevant requirements of SY / T5405-2019 "Test Methods and Evaluation Indicators for Performance of Corrosion Inhibitors for Acidification". This invention has the following characteristics:

[0035] Beneficial effects:

[0036] 1. The high-temperature acid corrosion inhibitor for titanium alloys of the present invention does not contain solid components and can be quickly dissolved in hydrochloric acid solution, which effectively improves the efficiency of on-site acid preparation.

[0037] 2. The high-temperature acidification corrosion inhibitor for titanium alloys of the present invention contains a large number of N and O adsorption groups, which promotes the adsorption of the corrosion inhibitor on the surface of titanium alloys.

[0038] 3. The high-temperature acid corrosion inhibitor for titanium alloys of the present invention contains high-valence organic metal ions. After being adsorbed on the surface of titanium alloys, it can effectively change the surface potential distribution of titanium alloys, increase the surface potential of titanium alloys, increase the resistance to hydrogen evolution reaction in strong acid systems, significantly improve the corrosion inhibition performance of the inhibitor, and significantly reduce the corrosion rate.

[0039] 4. The titanium alloy high-temperature acid fracturing corrosion inhibitor of the present invention has a simple production process, requires no special equipment, and can effectively reduce the safety and environmental risks caused by severe corrosion of titanium alloy tubing in acid fracturing fluid. Attached Figure Description

[0040] Figure 1 The image shows the infrared spectrum of the chloroplatinic acid cortex compound diimidazolin. Detailed Implementation

[0041] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0042] Example 1

[0043] This embodiment provides a high-temperature acidification corrosion inhibitor for titanium alloys, which is prepared by the following steps:

[0044] (1) Diethylenetriamine and sebaceous acid were dissolved in xylene (the mass of xylene was 1.5 times the total mass of diethylenetriamine and sebaceous acid), and amidation reaction was carried out at 120℃ for 4 h. Then the temperature was raised to 200℃ and the reaction was carried out for 6 h to obtain sebaceous diimidazoline intermediate. The molar ratio of diethylenetriamine to sebaceous acid was 2.2:1. Xylene and water generated in the reaction were collected and recycled through a reflux device and could be reused.

[0045] (2) Cool down to 120℃, add chloroplatinic acid, stir for 30 min, and after the reaction is complete, chloroplatinic acid sebum diimidazoline compound is obtained. The molar ratio of chloroplatinic acid to sebum diimidazoline intermediate is 2:1. Figure 1 The infrared spectrum of diimidazole chloroplatinic acid sebum is shown, where at 3409 cm⁻¹... -1 1652cm -1 1550cm -1 It has a strong absorption peak at 3409 cm⁻¹, among which 3409 cm⁻¹ has -1 The antisymmetric stretching vibration of NH is 1652 cm. -1 The peak at 1550 cm⁻¹ is the characteristic absorption peak of azazoline, representing the C=N double bond. -1 The presence of CN single bond stretching vibrations nearby confirms that this compound is a diimidazoline compound of chloroplatinic cortex.

[0046] (3) Cool down to 50°C, add chloroplatinic acid sebum diimidazoline compound, sodium molybdate, sodium nitrate, octylphenol polyoxyethylene ether, 2-methyl-3-butyn-2-ol and water in a mass ratio of 30:6:5:2:15:42 to obtain the high-temperature acidification corrosion inhibitor for the titanium alloy.

[0047] Example 2

[0048] This embodiment provides a high-temperature acidification corrosion inhibitor for titanium alloys, which is prepared by the following steps:

[0049] (1) Diethylenetriamine and octanoic acid were dissolved in xylene (the mass of xylene was 1.5 times the total mass of diethylenetriamine and octanoic acid), and amidation reaction was carried out at 120℃ for 5 h. Then the temperature was raised to 200℃ and the reaction was carried out for 8 h to obtain octanoic acid diimidazoline intermediate. The molar ratio of diethylenetriamine to octanoic acid was 2.4:1. Xylene and water generated in the reaction were collected and recovered by reflux device and could be reused.

[0050] (2) Cool down to 120℃, add chloroplatinic acid, stir for 40 min, and after the reaction is complete, chloroplatinic acid diimidazoline compound is obtained. The molar ratio of chloroplatinic acid to diimidazoline diimidazoline intermediate is 2:1.

[0051] (3) Cool down to 50°C and add chloroplatinic acid diimidazoline compound, sodium molybdate, sodium nitrate, octylphenol polyoxyethylene ether, 2-methyl-3-butyn-2-ol and ethanol in a mass ratio of 25:8:7:3:12:45 to obtain the high-temperature acidification corrosion inhibitor for the titanium alloy.

[0052] Example 3

[0053] This embodiment provides a high-temperature acidification corrosion inhibitor for titanium alloys, which is prepared by the following steps:

[0054] (1) Diethylenetriamine and azelaic acid were dissolved in xylene (the mass of xylene was 1.5 times the total mass of diethylenetriamine and azelaic acid) and subjected to an amidation reaction at 130°C for 6 h. Then the temperature was raised to 220°C and the reaction was carried out for 8 h to obtain azelaic acid diimidazoline intermediate. The molar ratio of diethylenetriamine to azelaic acid was 2.6:1. The xylene and the water generated in the reaction were collected and recovered by a reflux device and could be reused.

[0055] (2) Cool down to 120℃, add chloroplatinic acid, stir for 60 min, and after the reaction is complete, chloroplatinic acid azelaic acid diimidazoline compound is obtained. The molar ratio of chloroplatinic acid to azelaic acid diimidazoline intermediate is 2.1:1.

[0056] (3) Cool down to 60°C and add chloroplatinic azelaic acid diimidazoline compound, sodium molybdate, sodium nitrate, octylphenol polyoxyethylene ether, 2-methyl-3-butyn-2-ol and methanol in a mass ratio of 20:10:10:5:15:40 to obtain the high-temperature acidification corrosion inhibitor for the titanium alloy.

[0057] Example 4

[0058] This embodiment provides a high-temperature acidification corrosion inhibitor for titanium alloys, which is prepared by the following steps:

[0059] (1) Diethylenetriamine and dodecanoic acid were dissolved in xylene (the mass of xylene was 1.5 times the total mass of diethylenetriamine and dodecanoic acid) and subjected to an amidation reaction at 125°C for 5 h. Then the temperature was raised to 210°C and reacted for 7 h to obtain a dodecanoic acid diimidazoline intermediate. The molar ratio of diethylenetriamine to dodecanoic acid was 2.3:1. The xylene and the water generated in the reaction were collected and recovered by a reflux device and could be reused.

[0060] (2) Cool down to 110℃, add chloroplatinic acid, stir for 60 min, and after the reaction is complete, chloroplatinic acid dodecanoic acid diimidazoline compound is obtained. The molar ratio of chloroplatinic acid to dodecanoic acid diimidazoline intermediate is 2.2:1.

[0061] (3) Cool down to 50°C, add chloroplatinic dodecanoic acid diimidazoline compound, sodium molybdate, sodium nitrate, octylphenol polyoxyethylene ether, 2-methyl-3-butyn-2-ol and water in a mass ratio of 20:8:6:5:10:51 to obtain the high-temperature acidification corrosion inhibitor for the titanium alloy.

[0062] Example 5

[0063] This embodiment provides a high-temperature acidification corrosion inhibitor for titanium alloys, which is prepared by the following steps:

[0064] (1) Diethylenetriamine and tetradecanoic acid were dissolved in xylene (the mass of xylene was 1.5 times the total mass of diethylenetriamine and tetradecanoic acid) and subjected to an amidation reaction at 130°C for 6 h. Then the temperature was raised to 200°C and the reaction was carried out for 8 h to obtain a tetradecanoic acid diimidazoline intermediate. The molar ratio of diethylenetriamine to tetradecanoic acid was 2.5:1. The xylene and the water generated in the reaction were collected and recovered by a reflux device and could be reused.

[0065] (2) Cool down to 100℃, add chloroplatinic acid, stir for 60 min, and after the reaction is complete, chloroplatinic acid tetradecanoic acid diimidazoline compound is obtained. The molar ratio of chloroplatinic acid to tetradecanoic acid diimidazoline intermediate is 2.4:1.

[0066] (3) Cool down to 50°C and add chloroplatinic acid tetradecanoic acid diimidazoline compound, sodium molybdate, sodium nitrate, octylphenol polyoxyethylene ether, 2-methyl-3-butyn-2-ol and methanol in a mass ratio of 28:10:8:2:15:35 to obtain the high-temperature acidification corrosion inhibitor for the titanium alloy.

[0067] Comparative Example 1

[0068] This comparative example provides a corrosion inhibitor, which is prepared according to Example 1 in CN117187814A. The steps are as follows: A high-temperature corrosion inhibitor for titanium alloys (hereinafter referred to as corrosion inhibitor) is composed of 40% ammonium tungstate, 1.5% sodium hydroxide, 10% sodium polyoxysuccinate and 48.5% water: The solvent is placed in a beaker, sodium hydroxide is added and stirred evenly to form a stable first agent; ammonium tungstate is slowly added to the first agent and stirred for 10min-30min to completely dissolve the ammonium tungstate to form a second agent with a certain corrosion inhibition effect; sodium polyoxysuccinate is added to the second agent and stirred for 5min-10min until the whole is uniform and transparent. By utilizing the synergistic effect of sodium polyoxysuccinate and precipitated acid salt, a corrosion inhibitor that can effectively slow down corrosion is obtained.

[0069] Comparative Example 2

[0070] This comparative example provides a titanium corrosion inhibitor, which is prepared according to Example 1 in CN116180087A, and the steps are as follows:

[0071] Add 200 ml of ethanol, 18.31 g of 2,4-dinitroaniline, and 10 ml of 30% formaldehyde aqueous solution to a 500 ml three-necked flask equipped with an electric stirrer. Start the stirrer to dissolve the substances and control the temperature of the reaction solution to 15-35℃. Add 20 g of solid sodium hydroxide to the reaction solution and stir for 10 minutes. Then, add 10 g of cyclohexanone dropwise to the reaction solution and control the temperature of the reaction solution to 50-60℃. After adding all the raw materials, continue stirring and keep the reaction at the temperature for 12 hours to obtain an orange-red liquid. Concentrate the liquid to obtain a reddish-brown viscous oil.

[0072] Add 20g of the oily Mannich base prepared above, 40g of isopropanol, and 40g of N,N-dimethylformamide to a beaker to obtain 100g of titanium corrosion inhibitor.

[0073] Effect evaluation

[0074] The corrosion inhibitors obtained in Examples 1-5 and Comparative Examples 1-2 were evaluated for their effectiveness.

[0075] The effectiveness of the corrosion inhibitor was evaluated according to SY-T 5405-2019 "Test Methods and Evaluation Indicators for Corrosion Inhibitors Used in Acidification". The specific test results are shown in Table 1.

[0076] Table 1

[0077]

[0078]

[0079] As shown in Table 1, the high-temperature acid corrosion inhibitor for titanium alloys of the present invention can control the static corrosion rate of titanium alloys to 0.1 g / cm³ in 20% hydrochloric acid at 90°C. 2 Within h; at 120℃ and in 20% hydrochloric acid, the static corrosion rate of titanium alloy can be controlled to 0.2 g / cm³. 2 Within h; at 140℃ and in 20% hydrochloric acid, the static corrosion rate of titanium alloy can be controlled to 0.5 g / cm. 2 Within h, the high-temperature acidification corrosion inhibitor of the titanium alloy of the present invention has excellent corrosion inhibition effect.

Claims

1. A compound having the structure shown in Formula I: In Equation I, n is an integer between 6 and 12.

2. A method for preparing the compound according to claim 1, comprising the following steps: (1) Diethylenetriamine is subjected to an amidation reaction with a dicarboxylic acid compound, and then the temperature is raised to 200-220℃ and reacted for 6-8 hours to obtain an intermediate; (2) The intermediate obtained in step (1) is reacted with chloroplatinic acid to prepare the compound shown in Formula I.

3. The preparation method according to claim 2, wherein, In step (1), the temperature of the amidation reaction is 120-130℃.

4. The preparation method according to claim 2, wherein, In step (1), the molar ratio of diethylenetriamine to dicarboxylic acid compound is 2.2-2.6:

1.

5. The preparation method according to claim 2, wherein, In step (2), the molar ratio of the intermediate to chloroplatinic acid is 1:2.0-2.

4.

6. A high-temperature acid corrosion inhibitor for titanium alloys, comprising a compound of formula I in a mass ratio of 20-30:6-10:5-10:2-5:10-15, molybdate, nitrate, octylphenol polyoxyethylene ether, 2-methyl-3-butyn-2-ol, and the remainder being a solvent.

7. The application of the titanium alloy high-temperature acidizing corrosion inhibitor according to claim 6 in fracturing and acidizing operations, comprising the following steps: The titanium alloy high-temperature acidizing corrosion inhibitor is used in fracturing and acidizing operations in oil and gas field development.

8. The application according to claim 7, wherein, The ambient temperature for fracturing and acidizing operations in the oil and gas field development is 90-140℃. And / or, the hydrochloric acid concentration in the environment of the fracturing and acidizing operations in the oil and gas field development is 15-20 wt%.

9. The application according to claim 7, wherein, The environmental pressure for fracturing and acidizing operations in the oil and gas field development is ≤16MPa.

10. The application according to claim 7, wherein, The rotation speed in the environment for fracturing and acidizing operations in the oil and gas field development is ≤60 rpm.

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