Preparation method and application of triazine-based complex acidizing corrosion inhibitor
Patent Information
- Application Number
- CN202611140483.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-30
- Publication Date
- 2026-08-28
AI Technical Summary
[0006]本发明的目的在于提供一种三嗪基复合酸化缓蚀剂及其制备方法，以解决现有酸化缓蚀剂在高温环境下缓蚀性能不足、吸附膜稳定性差的问题
。
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Figure CN122648070A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the fields of applied chemistry and corrosion protection technology in oil and gas fields, specifically to the preparation and application of a triazine-based composite acidification corrosion inhibitor. Background Technology
[0002] In the process of oil and gas field development, acidizing is an important measure to improve reservoir permeability and promote the production of oil and gas wells. However, while the acid reacts with the formation rocks, it also causes severe corrosion to metal equipment such as well tubing and casing. The corrosion problem is even more prominent under complex conditions such as high acidity, high temperature and high salinity.
[0003] Currently used acidizing corrosion inhibitors, such as imidazoline, Mannich bases, and heterocyclic compounds, generally exhibit good corrosion inhibition effects under medium and low temperature conditions. However, they are prone to thermal desorption, decomposition, or adsorption film instability in high-temperature environments, leading to a significant decrease in corrosion inhibition rate. Furthermore, single-component corrosion inhibitors often suffer from problems such as non-dense adsorption films, narrow applicable temperature ranges, and large dosages, making it difficult to meet the needs of acidizing operations in deep, high-temperature oil and gas reservoirs.
[0004] Domestically and internationally, the temperature resistance of corrosion inhibitors is mainly enhanced through the molecular structure design and synergistic compounding technology of triazine compounds. Among them, triazine compounds, due to their cyclic structure rich in nitrogen atoms, can serve as good adsorption sites on metal surfaces. By compounding modified triazine derivatives with alkynol synergists, a highly efficient acidification corrosion inhibitor is formed, which further enhances the ability of the corrosion inhibitor to reduce the corrosion rate. At the same time, this compounding system can form a dense mixed adsorption film, avoiding the defects of the non-dense film of single-component corrosion inhibitors, thus achieving a synergistic effect.
[0005] Therefore, we synthesized a triazine derivative corrosion inhibitor main agent through molecular design, which has multiple active adsorption sites and good temperature resistance. Then, we compounded it with an alkynyl alcohol synergist, so that the composite corrosion inhibitor with the synergist has a high corrosion inhibition rate, good temperature resistance and dense adsorption film formation ability. Summary of the Invention
[0006] The purpose of this invention is to provide a triazine-based composite acid corrosion inhibitor and its preparation method, so as to solve the problems of insufficient corrosion inhibition performance and poor adsorption film stability of existing acid corrosion inhibitors under high temperature environment.
[0007] To achieve the above objectives, the present invention adopts the following technical solution: the triazine-based composite acid corrosion inhibitor is composed of corrosion inhibitor main component C1 and synergist 1,1,3-triphenyl-2-propynyl alcohol. The structural formula of corrosion inhibitor main component C1 is as follows: .
[0008] To achieve the above objectives, the present invention provides a method for preparing a triazine-based composite acid corrosion inhibitor, comprising the following steps: S1. Under ice bath and stirring conditions, 0.11 mol n-octylamine was slowly added dropwise to 100 mL of toluene solution containing 0.10 mol cyanuric chloride, the pH was adjusted to 8-9, and the reaction was carried out at 0-5℃ for 6 hours; after the reaction was completed, a white solid intermediate 1 was obtained after post-treatment. S2. Dissolve 0.10 mol of intermediate 1 in 150 mL of acetone, heat to 45-50 °C, add a water-acetone mixed solution containing 0.11 mol of 2-amino-1,3,4-thiadiazole and sodium hydroxide, reflux for 6 hours to obtain a light white solid intermediate 2. S3. Add 0.01 mol of intermediate 2 in portions to 40 mL of n-heptane solution containing 0.02 mol of N,N-dimethyl-1,3-propanediamine, and stir at 20-25 °C for 2 hours. After the reaction is complete, filter, wash and dry to obtain the target corrosion inhibitor C1. S4. Mix the corrosion inhibitor main agent C1 obtained in step S3 with the synergist 1,1,3-triphenyl-2-propynyl alcohol (hereinafter referred to as TPP) and stir for 30 minutes to obtain triazine-based composite acid corrosion inhibitor (hereinafter referred to as CT-1).
[0009] Preferably, the molar ratio of cyanuric chloride to n-octylamine in step S1 is 1:1.1.
[0010] Preferably, the solution used to adjust the pH in step S1 is a sodium carbonate solution, and the pH of the system is adjusted to 8-9.
[0011] Preferably, the molar ratio of intermediate 1 to 2-amino-1,3,4-thiadiazole and sodium hydroxide in step S2 is 1:1.1:1.1.
[0012] Preferably, the molar ratio of intermediate 2 to N,N-dimethyl-1,3-propanediamine in step S3 is 1:2.
[0013] Preferably, the mass ratio of the corrosion inhibitor main agent C1 to the synergist 1,1,3-triphenyl-2-propynyl alcohol in step S4 is 7:3.
[0014] Furthermore, the present invention also provides a triazine-based composite acid corrosion inhibitor, obtained by the above preparation method.
[0015] Furthermore, the amount of corrosion inhibitor added according to the present invention is 0.5% to 1.5% of the total mass of the acid solution.
[0016] Furthermore, the present invention also provides the application of the above-mentioned triazine-based composite acidizing corrosion inhibitor in oil and gas well acidizing operations.
[0017] The reaction formula of this invention is as follows: .
[0018] The beneficial effects of this invention are as follows: The triazine ring structure can form a dense protective film on the metal surface, which prevents further corrosion of the metal by isolating it from the corrosive medium; the thiadiazole ring contains nitrogen, sulfur, and other heteroatoms that readily provide lone pairs of electrons, enabling it to form a stable chemisorption film on the metal surface through polar functional groups, enhancing the binding force between the corrosion inhibitor molecules and the metal matrix; furthermore, the thiadiazole ring has good thermal stability, effectively protecting the metal from corrosion in high-temperature acidic environments; the long-chain alkanes also form on the metal surface... The hydrophobic layer plays a role in corrosion inhibition. By introducing long-chain alkanes, the coverage area of molecules on the metal surface is increased, improving the density of the corrosion-inhibiting film. The long-chain alkanes also work synergistically with the triazine ring and thiadiazole ring to achieve the corrosion inhibition effect. The alkynyl group and benzene ring structure in the synergist 1,1,3-triphenyl-2-propynol have a good filling effect. At the same time, 1,1,3-triphenyl-2-propynol also has a good synergistic effect, which can fill the gaps between C1 molecules, making the corrosion-inhibiting film more dense and providing better corrosion inhibition for the metal. Attached Figure Description
[0019] Figure 1 This is a synthesis circuit diagram of corrosion inhibitor main agent C1 in Example 1 of the present invention; Figure 2 This is a graph showing the variation of corrosion inhibition rate of the corrosion inhibitor under different compounding ratios in Example 2 of the present invention; Figure 3 The infrared spectrum of corrosion inhibitor C1 in Example 4 of this invention; Figure 4 This is a graph showing the corrosion inhibition performance of corrosion inhibitor CT-1 in Example 5 of the present invention at different temperatures; Figure 5 The electrochemical impedance spectroscopy and polarization curve of corrosion inhibitor CT-1 in 15% HCl solution in Example 6 of the present invention are shown, where (a) is the Nyquist plot, (b) is the Bode plot, and (c) is the polarization curve. Figure 6 The initial (equilibrium) adsorption configurations of C1 and TPP with different ratios on the Fe(110) surface in Example 7 of the present invention are (a) 1:9 (b) 3:7 (c) 5:5 (d) 7:3 (e) 9:1, where (A) is the initial adsorption configuration diagram and (B) is the equilibrium adsorption configuration diagram. Figure 7 This is a graph showing the adsorption energy variation of different ratios in Example 7 of the present invention; Figure 8 The images are SEM images of the surface of N80 steel before and after corrosion in Example 8 of the present invention, where (a) is the blank group, (b) is the group with C1 added, and (c) is the group with CT-1 added. Figure 9 The above are the surface EDS energy dispersive spectra of N80 steel before and after corrosion in Example 8 of this invention; Figure 10 The images show the three-dimensional AFM morphology of the N80 steel surface before and after corrosion in Example 8 of the present invention, where (a) is the blank group, (b) is the group with C1 added, and (c) is the group with CT-1 added. Figure 11 This is a test diagram of the surface contact angle of N80 steel before and after corrosion in Example 8 of the present invention. Detailed Implementation
[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this invention are only for explaining this invention and are not intended to limit this invention. Any product that is the same as or similar to this invention, derived by any person under the guidance of this invention or by combining features of this invention with other prior art, falls within the protection scope of this invention.
[0021] For any experimental steps or conditions not specified in the examples, they can be performed according to the conventional experimental steps or conditions described in the prior art; for reagents and other instruments whose manufacturers are not specified, they are all conventional reagent products that can be obtained commercially.
[0022] Example 1: Synthesis of corrosion inhibitor main agent C1, the synthesis route is as follows: Figure 1 As shown: S1. Under ice bath and stirring conditions, 0.11 mol n-octylamine was slowly added dropwise to 100 mL of toluene solution containing 0.10 mol cyanuric chloride, the pH was adjusted to 8-9, and the reaction was carried out at 0-5℃ for 6 hours; after the reaction was completed, a white solid intermediate 1 was obtained after post-treatment. S2. Dissolve 0.10 mol of intermediate 1 in 150 mL of acetone, heat to 45-50 °C, add a water-acetone mixed solution containing 0.11 mol of 2-amino-1,3,4-thiadiazole and sodium hydroxide, reflux for 6 hours to obtain a light white solid intermediate 2. S3. Add 0.01 mol of intermediate 2 in portions to 40 mL of n-heptane solution containing 0.02 mol of N,N-dimethyl-1,3-propanediamine, and stir at 20-25 °C for 2 hours. After the reaction is complete, filter, wash and dry to obtain the target corrosion inhibitor C1.
[0023] Example 2: Screening of synergists. Corrosion inhibitor main component C1 and synergist TPP were compounded at different mass ratios to investigate their effect on corrosion inhibition performance. Corrosion inhibitors with C1:TPP mass ratios of 1:9, 3:7, 5:5, 7:3, and 9:1 were prepared, with C1 and TPP used alone as controls. A 4-hour weight loss experiment was conducted on N80 steel sheets in a 15% hydrochloric acid solution at 90℃ with a total inhibitor addition of 1.0 wt%. The results are shown in [Figure number missing]. Figure 2 The corrosion inhibition rate was highest when C1:TPP = 7:3, reaching 87.6%, which was significantly higher than that of using C1 or TPP alone, indicating a significant synergistic effect between the two.
[0024] Example 3: Preparation of composite corrosion inhibitor CT-1: The corrosion inhibitor main agent C1 and the synergist 1,1,3-triphenyl-2-propynyl alcohol are mixed evenly at a mass ratio of 7:3 and stirred at room temperature for 30 minutes.
[0025] Example 4: Structural characterization of the corrosion inhibitor. The infrared spectrum of the main component C1 of the corrosion inhibitor synthesized in Example 1 is shown below. Figure 3 As shown in the figure, 3257cm -1 The absorption peak for the NH stretching vibration is located at 2924-2856 cm⁻¹. -1 The peak at 1507 cm⁻¹ represents the stretching vibration of the CH bond in the alkyl chain. -1 The peak at 1362 cm⁻¹ represents the stretching vibration of the C=N double bond. -1 The peak at 575 cm⁻¹ is a characteristic peak of the CN bond. -1 The peak at this location is a characteristic peak of the CS bond.
[0026] Example 5: Evaluation of the corrosion inhibition performance of the corrosion inhibitor, examining the corrosion inhibition performance of CT-1 at different temperatures; Experimental conditions: Corrosive medium was 15wt% hydrochloric acid, CT-1 addition was 1.5wt%, temperatures were set at 90℃, 120℃ and 150℃ respectively, corrosion time was 4h, the test piece was N80 carbon steel, and the corrosion inhibition rate was calculated using the weight loss method. The results are shown in […]. Figure 4 As can be seen, CT-1 can maintain an effective corrosion inhibition effect at all test temperatures, demonstrating good adaptability.
[0027] Example 6: Electrochemical testing of the corrosion inhibitor. The corrosion inhibition behavior of CT-1 was evaluated using electrochemical methods. The tests were conducted on a CH660e electrochemical workstation using a three-electrode system: the working electrode was N80 carbon steel, the reference electrode was a saturated Ag / AgCl electrode, and the auxiliary electrode was a platinum sheet electrode. The electrolyte was a 15% HCl solution with 1.5 wt% CT-1 added. The test temperature was 25℃. The potentiodynamic polarization curve scan range was open circuit potential ±500 mV, and the scan rate was 1 mV / s. The electrochemical impedance spectroscopy test frequency range was 10... -2 ~10 5Hz, AC signal amplitude 10mV; simultaneously tested blank solution as a control, results as follows Figure 5 As shown: the polarization curve results show that after adding CT-1, the corrosion current density is significantly reduced and the corrosion potential shift is less than 85mV, indicating that CT-1 is a hybrid corrosion inhibitor; the impedance spectrum fitting data show that after adding CT-1, the charge transfer resistance is significantly increased and the corrosion inhibition efficiency can reach more than 98%, proving that it can form a high-resistance protective film on the metal surface.
[0028] Example 7: Molecular dynamics simulation to reveal the synergistic mechanism of C1 and TPP. The simulation system was constructed using Material Studio software; the Fe(110) crystal plane size was 29.79 Å × 29.79 Å, the solution layer contained 425 water molecules, 75 chloride ions, and 10 corrosion inhibitor molecules, and the total system size was 29.79 Å × 29.79 Å × 73.82 Å, with a vacuum layer thickness of 15 Å; the simulation was performed using the Forcite module, with the following parameters: Compass II force field, NVT ensemble, temperature 298 K, time step 1 fs, and a total of 2 million simulation steps. Figure 6 The adsorption model is shown in the figure for different mixing ratios of corrosion inhibitor C1 and TPP. As can be seen from the figure, when the C1 ratio is low, fewer corrosion inhibitor molecules are adsorbed on the Fe(110) surface, resulting in a sparse film with large gaps. As the C1 ratio increases to 5:5, the film coverage improves. When C1:TPP = 7:3, C1 molecules are adsorbed parallel to the Fe(110) surface to form a basic protective layer, and the small TPP molecules just fill the gaps between C1 molecules, forming the densest and most complete mixed adsorption film. When the ratio is further increased to 9:1, the film density decreases slightly due to insufficient TPP content and incomplete gap filling. The adsorption energy under different mixing ratios is further calculated, and the results are shown in the figure. Figure 7 The absolute value of the adsorption energy increases with the increase of the number of C1 molecules. When the compound ratio is 1:9 to 7:3, the adsorption energy shows a linear increasing trend, indicating that the optimal ratio is reached at 7:3. At this ratio, the corrosion inhibition effect is the most obvious and the adsorption film of the corrosion inhibitor is the most dense.
[0029] Example 8: Microscopic morphology analysis. The film formation effect of CT-1 on the surface of N80 steel was observed by SEM, EDS, AFM, and contact angle testing. N80 steel sheets were immersed in 15% hydrochloric acid solution at 90℃ for 4 hours, and 1.5wt% CT-1 was added. The blank control was the same treatment without corrosion inhibitor. SEM results are shown below. Figure 8 The surface of the blank steel sheet (a) is covered with corrosion pits and cracks, while the surface of the steel sheet (b) with added CT-1 is smooth and flat; EDS energy dispersive spectroscopy is as follows. Figure 9As shown, after adding CT-1, the C element content increased from 4.91% to 8.33%, while the Cl element content decreased from 2.04% to 0.05%, indicating that CT-1 formed a dense adsorption film on the steel sheet surface, effectively blocking Cl. - Erosion; AFM three-dimensional morphology as Figure 10 As shown, the surface of the blank steel sheet (a) is highly undulating with a roughness Ra of 231 nm, while the surface of the steel sheet (b) with added CT-1 is smoother, with the roughness Ra decreasing to 19.7 nm; the contact angle test results are as follows. Figure 11 As shown, the contact angle of the blank steel sheet (a) is 32°, indicating hydrophilicity; the contact angle of the steel sheet (b) with added CT-1 increases to 93°, indicating strong hydrophobicity. The above results indicate that CT-1 can form a dense, hydrophobic protective film on the surface of N80 steel, effectively slowing down corrosion.
[0030] Comparative Example 1: A method for preparing and utilizing a triazine-based composite acid corrosion inhibitor, differing from Example 1 in that the main corrosion inhibitor C1 is not added, and only the synergist TPP is used. A corrosion weight loss experiment was conducted on N80 steel sheets at 1.0 wt% in a 15% hydrochloric acid solution at 90°C for 4 hours.
[0031] Comparative Example 2: A method for preparing and utilizing a triazine-based composite acid corrosion inhibitor, differing from Example 1 in that the synergist TPP is not added, and only the main corrosion inhibitor C1 is used. A corrosion weight loss experiment was conducted on N80 steel sheets at 1.0 wt% in a 15% hydrochloric acid solution at 90°C for 4 hours.
[0032] Performance testing Corrosion inhibition performance test: Using 15% hydrochloric acid as the corrosion medium and N80 carbon steel, the corrosion inhibition performance of Examples 2-3 and Comparative Examples 1-2 was determined by corrosion plate test at 90℃ for 4 hours. The amount of corrosion inhibitor was 1.0 wt%. The results are shown in Table 1.
[0033] Table 1: Corrosion Inhibition Performance Test; ; As shown in Table 1, the corrosion inhibition rate of Comparative Example 2 using only the main corrosion inhibitor C1 was 71.51%, and the corrosion inhibition rate of Comparative Example 1 using only the synergist TPP was 85.00%. However, in Example 2, the corrosion inhibition rate reached 87.6% after C1 and TPP were mixed in a 7:3 ratio. The corrosion inhibition effect was significantly better than that of using either component alone, indicating that there is a significant synergistic effect between the main corrosion inhibitor C1 and the synergist TPP.
[0034] Temperature resistance test: Using 15% hydrochloric acid as the corrosion medium and N80 carbon steel, the corrosion inhibition performance of Example 1 was determined by a 4-hour corrosion test at 120℃ and 150℃. The amount of corrosion inhibitor was 1.5wt%. The results are shown in Table 2.
[0035] Table 2 Temperature resistance performance test; ; As shown in Table 2, the triazine-based composite acid corrosion inhibitor of the present invention can effectively inhibit the corrosion of N80 steel in hydrochloric acid in a wide temperature range of 90~150℃, exhibiting good temperature resistance.
[0036] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. The selection and detailed description of these embodiments in this specification are intended to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.
Claims
1. A method for preparing a triazine-based composite acid corrosion inhibitor, characterized in that... This corrosion inhibitor is a compound of corrosion inhibitor main agent C1 and synergist 1,1,3-triphenyl-2-propynyl alcohol; The corrosion inhibitor main component C1 is prepared by a stepwise substitution reaction of cyanuric chloride, n-octylamine, 2-amino-1,3,4-thiadiazole, and N,N-dimethyl-1,3-propanediamine, and its chemical structural formula is as follows: The triazine-based composite acid corrosion inhibitor is prepared as follows: S1. Under ice bath and stirring conditions, 0.11 mol n-octylamine was slowly added dropwise to 100 mL of toluene solution containing 0.10 mol cyanuric chloride, the pH was adjusted to 8-9, and the reaction was carried out at 0-5℃ for 6 hours; after the reaction was completed, a white solid intermediate 1 was obtained after post-treatment. S2. Dissolve 0.10 mol of intermediate 1 in 150 mL of acetone, heat to 45-50 °C, add a water-acetone mixed solution containing 0.11 mol of 2-amino-1,3,4-thiadiazole and sodium hydroxide, reflux for 6 hours to obtain a light white solid intermediate 2. S3. Add 0.01 mol of intermediate 2 in portions to 40 mL of n-heptane solution containing 0.02 mol of N,N-dimethyl-1,3-propanediamine, and stir at 20-25 °C for 2 hours. After the reaction is complete, filter, wash and dry to obtain the target corrosion inhibitor C1. S4. Mix the corrosion inhibitor main agent C1 obtained in step S3 with the synergist 1,1,3-triphenyl-2-propynyl alcohol (hereinafter referred to as TPP) and stir for 30 min to obtain triazine-based composite acid corrosion inhibitor (hereinafter referred to as CT-1).
2. The preparation method of a triazine-based composite acid corrosion inhibitor according to claim 1, characterized in that... The molar ratio of cyanuric chloride to n-octylamine in step S1 is 1:1.
1.
3. In the preparation method of the triazine-based composite acid corrosion inhibitor according to claim 1, the solution for adjusting the pH in step S1 is a sodium carbonate solution, and the pH of the system is adjusted to 8-9.
4. The preparation method of a triazine-based composite acid corrosion inhibitor according to claim 1, characterized in that... In step S2, the molar ratio of intermediate 1 to 2-amino-1,3,4-thiadiazole and sodium hydroxide is 1:1.1:1.
1.
5. The preparation method of a triazine-based composite acid corrosion inhibitor according to claim 1, characterized in that... The molar ratio of intermediate 2 to N,N-dimethyl-1,3-propanediamine in step S3 is 1:
2.
6. The preparation method of a triazine-based composite acid corrosion inhibitor according to claim 1, characterized in that... The mass ratio of the corrosion inhibitor main agent C1 to the synergist 1,1,3-triphenyl-2-propynyl alcohol is 7:
3.
7. The application of the triazine-based composite acid corrosion inhibitor according to claim 1, characterized in that... The corrosion inhibitor is added to oil and gas well acidizing operations to inhibit corrosion of metal equipment.
8. The application according to claim 7, characterized in that, The amount of corrosion inhibitor added is 0.5% to 1.5% of the total mass of the acid solution.
9. The application according to claim 7 or 8, characterized in that... The acid solution is a 15% hydrochloric acid solution by mass, the metal equipment is made of N80 carbon steel, and the temperature of the oil and gas well acidizing operation is 90℃~150℃.