Acidification corrosion inhibitor as well as preparation method, application and use method thereof

Abstract

The invention provides an acidizing corrosion inhibitor as well as a preparation method, application and a use method thereof, and relates to the technical field of chemical additives, the acidizing corrosion inhibitor comprises vanillyl alcohol and lauryl trimethyl ammonium bromide, and further comprises one or two of piperazine-1, 4-bis-ethanesulfonic acid and polyoxazoline. All chemical components used in the formula are easy to obtain and low in price; vanillyl alcohol is derived from vanillin, is a bio-based aromatic compound, and is green and environment-friendly; the vanillyl alcohol, the lauryl trimethyl ammonium bromide, the piperazine-1, 4-bis-ethanesulfonic acid and the polyoxazoline are biodegradable chemical substances, are environment-friendly and non-toxic, and have no negative influence on the environment and human life; the acidizing corrosion inhibitor has good solubility in an acidizing corrosive solution, has stability and high efficiency at high temperature, and is still stable and very effective at the high temperature up to 150 DEG C.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical additives, and in particular to an acidification corrosion inhibitor and a preparation method, application and use method thereof. Background Art

[0002] Many oil wells are located in rock formations containing materials such as calcium carbonate, dolomite, and siderite, which hinder the flow of oil during extraction. A technique called oil well acidizing is often used to optimize oil production, particularly in carbonate and sandstone reservoirs, by dissolving or expanding these rock formations to improve flow. For example, during carbonate acidizing, a strong acid solution (typically 15wt% HCl) is injected into a carbonate wellbore to etch the rock matrix, forming channels called wormholes, thereby enhancing oil flow. The carbonates react with the acid solution to produce a chloride brine, water, and carbon dioxide. This method effectively alleviates the problem of low wellbore permeability by creating new flow channels or expanding existing channels. While this method improves oil extraction efficiency, it also carries the risk of corrosion because the wellbore tubing is made of metal. Common steel grades used in oil well construction include API N80, L80, J55, and Super-13. The acidizing process exacerbates corrosion of metal components within the wellbore and the equipment used for acidizing. Summary of the Invention

[0003] The problem solved by the present invention is how to solve the problem of corrosion of metal parts and equipment during the acidification process.

[0004] In order to solve the above problems, the present invention provides an acidification corrosion inhibitor and its preparation method, application and use method.

[0005] In a first aspect, the present invention provides an acidification corrosion inhibitor comprising vanillyl alcohol and lauryltrimethylammonium bromide, and further comprising one or two of piperazine-1,4-bisethanesulfonic acid and polyoxazoline.

[0006] Optionally, the concentration of vanillyl alcohol is 0.1 to 0.14 g / mL, the concentration of lauryltrimethylammonium bromide is 0.034 to 0.06 g / mL, the concentration of piperazine-1,4-bisethanesulfonic acid is 0.05 to 0.07 g / mL, and the concentration of polyoxazoline is 0.08 to 0.1 g / mL.

[0007] Optionally, methanol and potassium iodide are also included.

[0008] Optionally, the concentration of potassium iodide is 0.08 to 0.1 g / mL.

[0009] Optionally, water, ethanol and potassium iodide are also included.

[0010] Optionally, the volume ratio of ethanol to water is 11 to 12, and the concentration of potassium iodide is 0.08 to 0.1 g / mL.

[0011] In a second aspect, the present invention provides a method for preparing an acidification corrosion inhibitor as described in any of the above items, comprising dissolving potassium iodide in a solvent, adding vanillin and lauryltrimethylammonium bromide in sequence and dissolving them completely, adding one or two of piperazine-1,4-bisethanesulfonic acid and polyoxazoline and dissolving them completely to obtain an acidification corrosion inhibitor.

[0012] Optionally, the solvent is a mixture of water and ethanol or methanol.

[0013] In a third aspect, the present invention provides a use of the acid corrosion inhibitor as described in any one of the above items for inhibiting metal acid corrosion.

[0014] In a fourth aspect, the present invention provides a method for using the acidification corrosion inhibitor as described in any of the above items, wherein the acidification corrosion inhibitor is added to a 15wt.% to 28wt.% HCl solution used for acidifying metals, so that the volume fraction of the acidification corrosion inhibitor is 2.5% to 3.5%.

[0015] The acidification corrosion inhibitor of the present invention and its preparation method, application and use method have the following beneficial effects: the acidification corrosion inhibitor includes vanillyl alcohol and lauryltrimethylammonium bromide, and also includes one or two of piperazine-1,4-bisethanesulfonic acid and polyoxazoline. All chemical components used in the formula are easily available and inexpensive. Vanillyl alcohol is derived from vanillin and is a bio-based aromatic compound that is green and environmentally friendly. Vanillyl alcohol, lauryltrimethylammonium bromide, piperazine-1,4-bisethanesulfonic acid and polyoxazoline are all biodegradable chemical substances, are environmentally friendly and non-toxic, and have no negative impact on the environment and human life. The acid corrosion inhibitor has good solubility in acid corrosive solutions, and is stable and highly effective at high temperatures. It is still stable and very effective at high temperatures up to 150°C. After immersion of low carbon steel in 15wt.% and 28wt.% HCl solutions at 95°C for 6 hours, the acid corrosion inhibition efficiency exceeds 97%. After immersion of low carbon steel in 15wt.% and 28wt.% HCl solutions at 150°C for 3 hours, the acid corrosion inhibition efficiency reaches 99% and 97%, respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a bar graph showing the corrosion rate of T95 carbon steel under different formulations after being immersed in a 15 wt.% HCl solution at 95°C for 6 hours in the effect example;

[0017] Figure 2This is a bar chart showing the inhibition efficiency of T95 carbon steel under different formulations after being immersed in a 15 wt.% HCl solution at 95°C for 6 hours in the effect example;

[0018] Figure 3 This is a bar graph showing the corrosion rate of T95 carbon steel under different formulations after being immersed in a 28 wt.% HCl solution at 95°C for 6 hours in the effect example;

[0019] Figure 4 This is a bar chart showing the inhibition efficiency of T95 carbon steel under different formulations after being immersed in a 28 wt.% HCl solution at 95°C for 6 hours in the effect example;

[0020] Figure 5 This is a bar graph showing the corrosion rate of T95 carbon steel under different formulations after being immersed in a 15 wt.% HCl solution at 150°C for 6 hours in the effect example;

[0021] Figure 6 This is a bar chart showing the inhibition efficiency of T95 carbon steel under different formulations after being immersed in a 15 wt.% HCl solution at 150°C for 6 hours in the effect example;

[0022] Figure 7 This is a bar graph showing the corrosion rates of T95 carbon steel in different concentrations of F9 formulations and commercial inhibitor CI after being immersed in 15 wt.% and 28 wt.% HCl solutions at 150°C for 3 hours in the effect examples;

[0023] Figure 8 This is a bar graph showing the inhibition efficiency of T95 carbon steel in different concentrations of F9 formulations and commercial inhibitor CI after being immersed in 15wt.% and 28wt.% HCl solutions at 150°C for 3 hours in the effect examples;

[0024] Figure 9 (a) is a photo of the T95 carbon steel sample before corrosion;

[0025] Figure 9 (b) is a corrosion photograph of a T95 carbon steel sample after being immersed in a 28 wt.% HCl solution at 95°C without an inhibitor for 6 hours;

[0026] Figure 9 (c) is a corrosion photograph of a T95 carbon steel sample after being immersed in a 95°C, 28 wt.% HCl solution containing 3% by volume of F9 for 6 hours;

[0027] Figure 9 (d) is a corrosion photograph of a T95 carbon steel sample after being immersed in a 15 wt.% HCl solution at 95°C containing 3% by volume of F9 for 6 hours;

[0028] Figure 9(e) is a corrosion photograph of a T95 carbon steel sample after being immersed in a 15 wt.% HCl solution at 95°C containing 3% by volume of a commercial inhibitor CI for 6 hours. DETAILED DESCRIPTION

[0029] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein. Instead, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0030] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs. The terms used in the present invention description are only for the purpose of describing specific embodiments and are not intended to limit the present invention;

[0031] As used herein, the term "including" and its variations are open-ended, i.e., "including but not limited to"; the term "based on" means "based at least in part on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments." Definitions of other terms are provided in the following description.

[0032] In related technologies, the use of corrosion inhibitors is crucial during acidizing operations to enhance oil and gas production or recover hydrocarbons from depleted wells. Corrosion inhibitors are synthetic or natural compounds that, when added in small quantities to a corrosive solution, can reduce the rate of metal corrosion. Corrosion inhibitor technology is crucial to minimizing metal corrosion during the acidizing process. Selecting the appropriate corrosion inhibitor depends on factors such as the strength of the acid, the type of steel, the contact time, and the well temperature. The inhibitor's susceptibility to thermal decomposition and its effectiveness at high temperatures are important considerations in inhibitor selection.

[0033] Acidification corrosion inhibitors are divided into two categories: organic and polymer-based. Organic corrosion inhibitors include acetylenic alcohols, aromatic aldehydes, allylphenols, amines, amides, nitrogen-containing heterocyclic compounds (such as imidazoline, nitriles, imine salts, triazoles, pyridine and its derivatives or salts, quinoline derivatives, thiourea derivatives, thiocysteamine, thiocyanates, quaternary ammonium salts, and condensation products of aldehydes and amines. For polymer-based corrosion inhibitors, they include diethylamine and 1,4-dichlorobutane, morpholine and 1,4-dichlorobutene, diethylamine and epichlorohydrin, 4-vinylpyridine and benzyl chloride, 4-vinylpyridine and bromobutyl, 4-vinylpyridine and iodoethane, p-vinylpyridine and benzoyl peroxide quaternized methyl iodide, p-vinylpyridine and benzoyl peroxide mixture. Propargyl alcohol, chitosan / silver nanoparticle complexes, biopolymer-based dextran graft copolymers, random copolymers (containing diallylmethylamine and N1,N1-diallyl-N1-methyl-N6,N6,N6-tripropylhexane-1,6-diammonium dibromide units + potassium iodide), carboxymethyl cellulose / silver nanocomposites, and polypropylene glycol. These compounds inhibit corrosion through an adsorption mechanism, that is, they adhere to the metal surface to form a protective layer. However, some of these compounds and formulations have problems such as high toxicity, non-biodegradability, loss of inhibitory properties due to decomposition and degradation at high temperatures (especially above 90°C), and high prices due to the rigorous synthesis process.

[0034] Propynol is an effective steel corrosion inhibitor. In most formulations, organic compounds act synergistically with propynol. For example, propynol-formaldehyde mixtures, propynol-propylene mixtures, and propynol-benzoquinoline chloride formulations have been reported as highly effective acidification inhibitors. However, propynol has a median lethal dose (LD50) of 20 mg / kg, classifying it as acutely toxic Category 3 (oral) and Category 2 (inhalation), and has adverse effects on the environment and human health. It can cause severe skin burns, drowsiness or dizziness, and potentially damage organs, particularly the eyes. Amines, especially alkanolamines (a common amine component in most disclosures), react with acidic gases to form corrosive substances. The use of imidazoline compounds also presents challenges, as most are non-biodegradable. Polymers, particularly natural polymers, are attractive for a variety of applications, including acidification corrosion inhibition, due to their multiple adsorption sites, environmental friendliness, non-toxicity, and cost-effectiveness. However, many polymers are unsuitable for acidification conditions because they readily degrade at high temperatures, potentially leading to blockage of flow channels.

[0035] In addition to the toxicity issues discussed above, we also discovered a serious research gap in our previous report that requires urgent attention. The study revealed that there is almost no information available on acidizing inhibitors that can be used at temperatures ≥150°C. As shallow oil wells are depleted, offshore oil and gas drilling activities continue to advance to further offshore areas and deeper underwater to find hydrocarbons in low-risk areas. As a result, wellbore temperatures are rising (most wells are currently ≥150°C), however, existing acidizing inhibitors are difficult to work in environments with temperatures ≥150°C, which causes current corrosion inhibitors to lose their inhibitory performance.

[0036] According to the Paris Committee (PARCOM) regulations and the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), all chemicals, including corrosion inhibitors, must meet specific criteria: (i) a biodegradation rate of at least 70% within 28 days, (ii) a median lethal dose (LD50) value of at least 3000 mg / L, and (iii) a bioaccumulation (log Po / w) value of less than 3. Therefore, there is a great demand for effective, low-cost, and environmentally friendly acid corrosion inhibitors.

[0037] In response to the problems existing in the above-mentioned related technologies, this embodiment provides an acidification corrosion inhibitor and its preparation method, application and use method.

[0038] An acidification corrosion inhibitor provided by an embodiment of the present invention includes vanillyl alcohol and lauryltrimethylammonium bromide, and also includes one or two of piperazine-1,4-bisethanesulfonic acid and polyoxazoline.

[0039] In this embodiment, all chemical components used in the formulation are easily available and inexpensive; vanillyl alcohol is derived from vanillin, a bio-based aromatic compound that is green and environmentally friendly; vanillyl alcohol, lauryltrimethylammonium bromide, piperazine-1,4-bisethanesulfonic acid, and polyoxazoline are all biodegradable chemicals that are environmentally friendly and non-toxic, and have no negative impact on the environment and human life; the acid corrosion inhibitor has good solubility in acid corrosive solutions, and is stable and highly effective at high temperatures, and remains stable and very effective at high temperatures up to 150°C. After a 3% (v / v) acid corrosion inhibitor is in 15wt.% and 28wt.% HCl solutions, the acid corrosion inhibition efficiency of mild steel exceeds 97% after immersion at 95°C for 6 hours. After a 3% (v / v) acid corrosion inhibitor is in 15wt.% and 28wt.% HCl solutions, the acid corrosion inhibition efficiency reaches 99% and 97%, respectively, after immersion at 150°C for 3 hours on mild steel.

[0040] Specifically, the chemical formula of vanillyl alcohol is as follows:

[0041]

[0042] The chemical formula of lauryltrimethylammonium bromide is as follows:

[0043]

[0044] The chemical formula of piperazine-1,4-bisethanesulfonic acid is as follows:

[0045]

[0046] The chemical formula of polyoxazoline is as follows:

[0047]

[0048] Optionally, the concentration of vanillyl alcohol is 0.1 to 0.14 g / mL, the concentration of lauryltrimethylammonium bromide is 0.034 to 0.06 g / mL, the concentration of piperazine-1,4-bisethanesulfonic acid is 0.05 to 0.07 g / mL, and the concentration of polyoxazoline is 0.08 to 0.1 g / mL.

[0049] Optionally, methanol and potassium iodide are also included.

[0050] In this optional embodiment, methanol is used as a solvent to dissolve vanillin, lauryl trimethylammonium bromide, piperazine-1,4-bisethanesulfonic acid and polyoxazoline. Potassium iodide is a key component of acid corrosion inhibitor and can synergistically inhibit corrosion. Potassium iodide and Fe 3+ The metal ions form stable complexes (such as [FeI4] - ), which can reduce the catalytic corrosion of free metal ions to acids (such as HCl); potassium iodide also serves as a stabilizer for acidification corrosion inhibitors, which can inhibit the decomposition and failure of vanillyl alcohol, lauryltrimethylammonium bromide, piperazine-1,4-bisethanesulfonic acid and polyoxazoline in high temperature acidic environments.

[0051] Optionally, the concentration of potassium iodide is 0.08 to 0.1 g / mL.

[0052] Optionally, water, ethanol and potassium iodide are also included.

[0053] In this alternative embodiment, a mixture of water and ethanol is used as a solvent to dissolve vanillyl alcohol, lauryltrimethylammonium bromide, piperazine-1,4-bisethanesulfonic acid and polyoxazoline.

[0054] Optionally, the volume ratio of ethanol to water is 11 to 12, and the concentration of potassium iodide is 0.08 to 0.1 g / mL.

[0055] Another embodiment of the present invention provides a method for preparing an acid corrosion inhibitor as described in any of the above items, comprising dissolving potassium iodide in a solvent, adding vanillin and lauryltrimethylammonium bromide in sequence and dissolving them completely, adding one or both of piperazine-1,4-bisethanesulfonic acid and polyoxazoline and dissolving them completely to obtain an acid corrosion inhibitor.

[0056] In this embodiment, the preparation procedure is simple, convenient and easy to prepare.

[0057] Optionally, the solvent is a mixture of water and ethanol or methanol.

[0058] Another embodiment of the present invention provides a use of the acid corrosion inhibitor as described in any one of the above items for inhibiting metal acid corrosion.

[0059] In this embodiment, the acid corrosion inhibitor is stable and highly effective at high temperatures, and remains stable and very effective at high temperatures up to 150°C. After immersing mild steel in 15wt.% and 28wt.% HCl solutions at 95°C for 6 hours, the acid corrosion inhibition efficiency exceeds 97%. After immersing mild steel in 15wt.% and 28wt.% HCl solutions at 150°C for 3 hours, the acid corrosion inhibition efficiency reaches 99% and 97%, respectively.

[0060] Another embodiment of the present invention provides a method for using the acidification corrosion inhibitor as described above, wherein the acidification corrosion inhibitor is added to a 15wt.% to 28wt.% HCl solution used for acidifying metals, so that the volume fraction of the acidification corrosion inhibitor is 2.5% to 3.5%.

[0061] The present invention is further described below with reference to specific embodiments.

[0062] Example 1

[0063] Acidification corrosion inhibitors were prepared according to the formulas and preparation steps of each group in Table 1.

[0064]

[0065]

[0066]

[0067] Effect embodiment

[0068] The corrosion rates of the acidified corrosion inhibitors prepared in each group of Example 1 were calculated using the weight loss method. T95 steel samples were used. The chemical composition (by mass percentage) of T95 steel is C: 0.35, P: 0.030, Mo: 0.85, Si: 0.45, S: 0.010, Cr: 1.50, Mn: 1.20, Ni: 0.99, and the remainder is Fe. The steel samples were obtained from Corrtest Instrument Co., Ltd. in Wuhan, China.

[0069] The dimensions of the T95 steel samples were: 8 cm in length, 2.8 cm in width, and 0.6 cm in thickness, with a surface area of ​​28.88 cm² or 4.48 in². The sample surfaces were pretreated according to ASTM G1-90. To achieve a mirror finish, the samples were wet-polished with silicon carbon paper (400 to 1200 grit). The samples were then rinsed with tap water and acetone to remove any residue that may have been generated during the polishing process. The samples were then dried in a sample dryer at 40°C and stored in a waterless desiccator until ready for use.

[0070] The weight loss experiment used a 200 ml PTFE-lined stainless steel autoclave. First, the PTFE-lined stainless steel autoclave was filled with 150 ml of the test solution, which was a 15 wt.% HCl solution. The acidified corrosion inhibitors prepared in each group of Example 1 were added to the HCl solution at a volume ratio of 3%. The HCl solution without the acidified corrosion inhibitor was used as the control (Blank) group. Two pre-weighed T95 samples were completely immersed in the test solution, and the autoclave was carefully sealed. They were then placed in an oven maintained at 95°C for 6 hours. After the experiment, the oven was closed and allowed to cool naturally to room temperature. The corroded samples were then removed and immersed in an acid pickling solution (50 g sodium hydroxide + 200 g zinc powder, prepared with distilled water to make a 1000 ml solution) for 10 minutes. They were gently wiped under tap water and acetone, blown dry with hot air, and reweighed. The corrosion rate (CR, mm / y) was calculated using Formula 1:

[0071]

[0072] Wherein, ΔW, ρ, A and t represent the average weight loss (mg), density (g·cm -3 ), surface area (cm 2 ) and exposure time (h).

[0073] The inhibitory efficiency (IE, %) of the formulation was estimated by Equation 2:

[0074]

[0075] Among them, C R(blank)is the corrosion rate of the control (Blank) group, C R(inhibited) is the corrosion rate of the acidified corrosion inhibitor group.

[0076] The corrosion rate calculation results are as follows: Figure 1 As shown, after the formal 6-hour exposure, it took more than 7 hours for the system to cool to room temperature and remove the samples. This cooling time was not included in the corrosion rate calculation. Figure 1 As can be seen, after immersing T95 carbon steel in a 15wt.% HCl solution without an inhibitor for 6 hours, the metal's corrosion rate reached a high of 641.22 mm / y. This means that performing an acidizing operation without a corrosion inhibitor would be disastrous. All formulations (F1 to F11) reduced the metal's corrosion rate. For formulations F6, F9, F10, and F11, the corrosion rates were all below 23 mm / y, indicating strong acidizing corrosion inhibition.

[0077] The inhibitory efficiency of the formula is as follows Figure 2 As shown in the figure, the protection efficiencies of F1, F2, F3, F4, and F5 were relatively low, at 37.95%, 46.97%, 58.89%, and 32.11%, respectively. However, F6, F7, F8, F9, F10, and F11 provided excellent protection for the T95 sample. F6, F7, F8, F9, F10, and F11 reduced the corrosion rate of the metal sample from 641.22 mm / y to 22.81 mm / y, 30.05 mm / y, 52.5 mm / y, 18.45 mm / y, 14.97 mm / y, and 22.94 mm / y, respectively. The corresponding corrosion inhibition efficiencies were 96.44%, 95.31%, 91.81%, 97.12%, 97.67%, and 96.42%, respectively. All of these inhibition efficiencies exceeded 95%, indicating strong inhibition performance against acidic corrosion.

[0078] A Teflon-lined stainless steel autoclave was filled with 150 ml of the test solution, a 28 wt.% HCl solution. The acidified corrosion inhibitors prepared in groups F6, F9, F10, and F11 of Example 1 were added to the HCl solution at a volume ratio of 3%. The HCl solution without the acidified corrosion inhibitor served as the control (Blank) group, and the HCl solution with the commercial inhibitor CI served as the CI group. Two pre-weighed T95 samples were completely immersed in the test solution, and the autoclaves were carefully sealed. They were then placed in an oven maintained at 95°C for different 6-hour periods. After the experiment, the ovens were closed and allowed to cool naturally to room temperature. The corroded samples were then removed and immersed in an acid wash solution (50 g sodium hydroxide + 200 g zinc powder, prepared in distilled water to a 1000 ml solution) for 10 minutes. The samples were then gently wiped with tap water and acetone, dried with hot air, and reweighed. The corrosion rate (CR, mm / y) was calculated by Equation 1, and the inhibition efficiency (IE, %) of the formulation was estimated by Equation 2.

[0079] Among them, the commercial inhibitor CI is a commercial inhibitor currently used by one of the world's leading oil and gas companies. It is composed of propargyl alcohol, potassium iodide (KI), sodium dodecyl sulfate (SDS), methanol and water.

[0080] The corrosion rate calculation results are as follows: Figure 3 As shown, after the formal 6-hour exposure, it took more than 7 hours for the system to cool to room temperature and remove the samples. This cooling time was not included in the corrosion rate calculation. Figure 3 It can be seen that the formulations and CI of groups F6, F9, F10, and F11 all significantly reduced the corrosion rate. The presence of F6, F9, F10, F11, and CI reduced the corrosion rate in the acid solution from 978.83 mm / y to 13.88 mm / y, 11.76 mm / y, 13.07 mm / y, 22.68 mm / y, and 22.81 mm / y, respectively. The corrosion rates were all below 23 mm / y, indicating strong inhibition of acid corrosion.

[0081] The inhibitory efficiency of the formula is as follows Figure 4 As shown in the figure, groups F6, F7, F9, F10, and F11 performed well compared to CI. The inhibition efficiency of F6 (98.58%), F9 (98.80%), and F10 (98.67%) was slightly higher than that of CI, and the inhibition performance of acid corrosion was stronger, which means that these formulations, especially F6, F9, and F10, can replace CI as an acid corrosion inhibitor.

[0082] A Teflon-lined stainless steel autoclave was filled with 150 ml of the test solution, a 15 wt.% HCl solution. The acidified corrosion inhibitors prepared in groups F9 and F10 of Example 1 were added to the HCl solution at a volume ratio of 3%. The HCl solution without the acidified corrosion inhibitor served as the control (Blank) group, and the HCl solution with the commercial inhibitor CI served as the CI group. Two pre-weighed T95 samples were completely immersed in the test solution, and the autoclaves were carefully sealed. The samples were then placed in separate ovens maintained at 150°C for 6 hours. After the experiment, the ovens were closed and allowed to cool naturally to room temperature. The corroded samples were then removed and immersed in an acid wash solution (50 g sodium hydroxide + 200 g zinc powder, prepared in distilled water to a 1000 ml solution) for 10 minutes. The samples were gently wiped with tap water and acetone, dried with hot air, and reweighed. The corrosion rate (CR, mm / y) was calculated using Equation 1, and the inhibition efficiency (IE, %) of the formulation was estimated using Equation 2.

[0083] The corrosion rate calculation results are as follows: Figure 5 As shown, after the formal 6-hour exposure, it took more than 7 hours for the system to cool to room temperature and remove the samples. This cooling time was not included in the corrosion rate calculation. Figure 5 It can be seen that the corrosion rate of metals inhibited by commercial inhibitor CI and group F9 formula in acid solution is between 236.61mm / y and 262.21mm / y. The inhibition efficiency of the formula is as follows: Figure 6 As shown, the inhibition efficiency ranged from 67.52% to 70.68%.

[0084] A Teflon-lined stainless steel autoclave was filled with 150 ml of test solution. The test solutions were 15 wt.% and 28 wt.% HCl solutions, respectively. The acidified corrosion inhibitor prepared in Group F9 of Example 1 was added to the HCl solutions at 2% and 3% by volume, respectively. HCl solutions without the acidified corrosion inhibitor served as controls (Blank). The commercial inhibitor CI was added to the HCl solutions at 2% and 3% by volume, respectively, serving as CI groups. Two pre-weighed T95 samples were completely immersed in the test solutions, and the autoclaves were carefully sealed. The samples were then placed in an oven maintained at 150°C for 3 hours. After the experiment, the ovens were closed and allowed to cool naturally to room temperature. The corroded samples were then removed and immersed in an acid wash solution (50 g of sodium hydroxide and 200 g of zinc powder, prepared in distilled water to a 1000 ml solution) for 10 minutes. The samples were then gently wiped with tap water and acetone, dried with hot air, and reweighed. The corrosion rate (CR, mm / y) was calculated by Equation 1, and the inhibition efficiency (IE, %) of the formulation was estimated by Equation 2.

[0085] The corrosion rate calculation results are as follows: Figure 7As shown, the inhibitory efficiency of the formula is as Figure 8 As shown, after the formal 6-hour exposure, it took more than 7 hours for the system to cool to room temperature and remove the samples. This cooling time was not included in the corrosion rate calculation. Figure 7 and Figure 8 As can be seen, 2wt.% and 3wt.% F9 concentrations effectively protected the metal from corrosion. A 3% volume ratio F9 formulation was a better corrosion inhibitor for T95 carbon steel in a 28wt.% HCl solution at 150°C. This concentration of F9 provided 98.67% and 96.61% inhibition efficiencies in 15wt.% HCl and 28wt.% HCl solutions, respectively, compared to 98.56% and 94.68% for 3% volume ratio CI, demonstrating strong inhibition of acidified corrosion.

[0086] like Figure 9 As shown, the photos of T95 carbon steel samples, (a) before corrosion; (b) corrosion after immersion in a 95℃, 28wt.% HCl solution without inhibitor for 6 hours; (c) corrosion after immersion in a 95℃, 28wt.% HCl solution containing 3% volume ratio F9 for 6 hours; (d) corrosion after immersion in a 95℃, 15wt.% HCl solution containing 3% volume ratio F9 for 6 hours; (e) corrosion after immersion in a 95℃, 15wt.% HCl solution containing 3% volume ratio commercial inhibitor (CI) for 6 hours. It can be seen that only the T95 carbon steel sample in (b) is severely corroded, and the inhibitors in (c), (d) and (e) have stronger inhibitory performance in acid corrosion.

[0087] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. An acidification corrosion inhibitor, characterized in that: The invention comprises vanillyl alcohol and lauryltrimethylammonium bromide, and further comprises one or two of piperazine-1,4-bisethanesulfonic acid and polyoxazoline.

2. The acidification corrosion inhibitor according to claim 1, characterized in that The concentration of the vanillyl alcohol is 0.1 to 0.14 g / mL, the concentration of the lauryltrimethylammonium bromide is 0.034 to 0.06 g / mL, the concentration of the piperazine-1,4-bisethanesulfonic acid is 0.05 to 0.07 g / mL, and the concentration of the polyoxazoline is 0.08 to 0.1 g / mL.

3. The acidification corrosion inhibitor according to claim 1, characterized in that Also included are methanol and potassium iodide.

4. The acidification corrosion inhibitor according to claim 3, characterized in that The concentration of the potassium iodide is 0.08 to 0.1 g / mL.

5. The acidification corrosion inhibitor according to claim 1, characterized in that Also includes water, ethanol and potassium iodide.

6. The acidification corrosion inhibitor according to claim 5, characterized in that The volume ratio of the ethanol to the water is 11 to 12, and the concentration of the potassium iodide is 0.08 to 0.1 g / mL.

7. A method for preparing the acidification corrosion inhibitor according to any one of claims 1 to 6, characterized in that: Potassium iodide is dissolved in a solvent, vanillyl alcohol and lauryltrimethylammonium bromide are added in sequence and dissolved completely, and one or two of piperazine-1,4-bisethanesulfonic acid and polyoxazoline are added and dissolved completely to obtain an acidification corrosion inhibitor.

8. The method for preparing the acidification corrosion inhibitor according to claim 7, characterized in that: The solvent is a mixture of water and ethanol or methanol.

9. Use of the acidic corrosion inhibitor according to any one of claims 1 to 6 for inhibiting metal acidic corrosion.

10. A method for using the acidification corrosion inhibitor according to any one of claims 1 to 6, characterized in that: The acidification corrosion inhibitor is added to a 15 wt.% to 28 wt.% HCl solution used for acidifying metals, so that the volume fraction of the acidification corrosion inhibitor is 2.5% to 3.5%.

Images