Compound for scale and corrosion inhibitor and scale and corrosion inhibitor

Abstract

The invention provides a compound for a scale and corrosion inhibitor and the scale and corrosion inhibitor. Compound for scale and corrosion inhibitor has structure as shown in formula I: # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the field of oilfield chemical agents, and particularly relates to a novel compound for a high-temperature water-soluble scale and corrosion inhibitor for a sulfur-containing gas field and a novel high-temperature scale and corrosion inhibitor for a sulfur-containing gas field containing the compound for a scale and corrosion inhibitor. Background Art

[0002] In the oil and gas production industry, due to the presence of components such as H2S, CO2, and inorganic salts, problems such as scaling, corrosion, and blockage of oil and gas field gathering pipelines and wellbores will occur, especially in the production of sulfur-containing gas fields. Sulfur-containing gas fields are one of the harshest corrosion environments in the oil and gas exploitation process. Highly toxic and strongly corrosive H2S will cause corrosion to the metal materials of downhole pipe strings and surface gathering and transportation equipment. In the process of oil and gas development, measures need to be taken to control corrosion and scaling problems. With the continuous progress of oil and gas resource exploitation technology, oil and gas development is advancing towards deeper and ultra-deeper layers, and the well depth and temperature records are constantly reaching new highs, making it difficult to control downhole corrosion in sulfur-containing gas fields.

[0003] Adding corrosion inhibitors and scale inhibitors is currently one of the most common practices, which has the characteristics of simple operation, low cost, and remarkable effects. Existing corrosion inhibitors usually have many problems when used at high temperatures: on the one hand, they degrade due to the decrease in their own stability; on the other hand, they desorb due to the decrease in the adsorption effect between the corrosion inhibitor and the metal. The effect of existing corrosion inhibitors usually drops sharply with the increase in temperature. Therefore, existing corrosion inhibitors generally have the problem that their effects at high temperatures are difficult to meet the usage requirements.

[0004] In summary, there is a current need to study high-temperature resistant scale and corrosion inhibitors suitable for sulfur-containing gas fields. Summary of the Invention

[0005] The purpose of the present invention is to provide a scale and corrosion inhibitor that can be applied to sulfur-containing gas fields and has high-temperature resistance performance, with excellent anti-corrosion / scale formation effects at high temperatures.

[0006] To achieve the above purpose, the present invention provides a compound for a scale and corrosion inhibitor, which has the structure shown in Formula I:

[0007]

[0008] The compound for a scale and corrosion inhibitor can be applied to the production of sulfur-containing gas fields, can be quickly adsorbed on the metal surface and is not easily denatured at high temperatures, and has excellent anti-corrosion / scale formation performance at high temperatures.

[0009] According to a specific embodiment of the present invention, preferably, R1 is selected from one of substituted or unsubstituted alkyl, aminoalkyl; more preferably, R1 is selected from one of them.

[0010] According to a specific embodiment of the present invention, preferably, R2 is selected from one of H and substituted or unsubstituted aryl; preferably, R2 is selected from one of the following. According to a specific embodiment of the present invention, preferably, R3 is selected from a substituted or unsubstituted heteroatom-containing five- or six-membered ring; preferably, R3 is selected from one of the following.

[0011] The present invention also provides a method for preparing a scale and corrosion inhibitor, which comprises the following steps:

[0012] Mix an aldehyde, a polyamine, a ketone and a first polar solvent to obtain a first mixture; wherein, the molar ratio of the aldehyde, the polyamine and the ketone is 1.0-1.2:0.5:1.0-1.2; the volume of the first polar solvent is 3-5 times the total volume of the aldehyde, the polyamine and the ketone;

[0013] Adjust the pH of the first mixture to 2-6, and then carry out a first heating reaction under the protection of an inert gas, and carry out a first purification treatment on the product obtained from the first heating reaction to remove the remaining reactants to obtain an intermediate product;

[0014] Mix a second polar solvent, sodium 2-hydroxy-3-chloropropyl phosphate (HCP) and the intermediate product to obtain a second mixture; wherein, the mass ratio of the second polar solvent, sodium 2-hydroxy-3-chloropropyl phosphate (HCP) and the intermediate product is 100:0.5-1:5-10;

[0015] Carry out a second heating reaction on the second mixture, and remove the solid precipitate in the product obtained from the second heating reaction, thereby preparing a scale and corrosion inhibitor.

[0016] The method for preparing a scale and corrosion inhibitor provided by the present invention can simply and quickly prepare a scale and corrosion inhibitor containing a compound for a scale and corrosion inhibitor having the structure shown in the above formula I.

[0017] According to a specific embodiment of the present invention, preferably, the polyamine includes at least one of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine.

[0018] According to a specific embodiment of the present invention, preferably, the aldehyde includes one of cinnamaldehyde, formaldehyde and benzaldehyde.

[0019] According to a specific embodiment of the present invention, preferably, the ketone includes one of 2-acetylthiazole, 1-acetylimidazole and 3-acetylpyridine.

[0020] According to a specific embodiment of the present invention, preferably, the first solvent includes at least one of absolute ethanol, deionized water, dimethyl sulfoxide, and N,N-dimethylformamide; more preferably, the first solvent is absolute ethanol.

[0021] According to a specific embodiment of the present invention, preferably, the second polar solvent includes at least one of absolute ethanol, deionized water, dimethyl sulfoxide, and N,N-dimethylformamide.

[0022] According to a specific embodiment of the present invention, preferably, the reagent used for pH adjustment of the first mixture is hydrochloric acid; further, based on the mass of hydrochloric acid being 100%, the mass concentration of HCl in hydrochloric acid is 5-20%.

[0023] According to a specific embodiment of the present invention, preferably, the temperature of the first heating reaction is 70-100 °C.

[0024] According to a specific embodiment of the present invention, preferably, the time of the first heating reaction is 4-10 h.

[0025] According to a specific embodiment of the present invention, preferably, the temperature of the second heating reaction is 75-95 °C.

[0026] According to a specific embodiment of the present invention, preferably, the time of the second heating reaction is 5-24 h.

[0027] According to a specific embodiment of the present invention, preferably, the first purification treatment of the product obtained from the first heating reaction includes: rotary evaporation and concentration of the product obtained from the first heating reaction until the solvent is completely volatilized, and then using a third polar solvent and an antisolvent to remove the remaining reactants, wherein the volume ratio of the third polar solvent to the antisolvent is 1:2-5;

[0028] More preferably, the temperature of rotary evaporation and concentration is 40-70 °C;

[0029] More preferably, using a third polar solvent and an antisolvent to remove the remaining reactants includes: adding a third polar solvent, then removing the solid precipitate, and then adding an antisolvent, and after stirring and mixing, performing ice bath extraction to remove the remaining reactants;

[0030] More preferably, the third polar solvent includes at least one of absolute ethanol, deionized water, dimethyl sulfoxide, and N,N-dimethylformamide;

[0031] More preferably, the antisolvent includes at least one of ether, ethyl acetate, methyl acetate, and acetone;

[0032] More preferably, the mass ratio of the product after rotary evaporation and concentration until the solvent is completely volatilized to the mass of the third polar solvent is 1:5-15.

[0033] According to a specific embodiment of the present invention, preferably, the method further includes:

[0034] Mixing the product obtained by removing the solid precipitate from the product obtained in the second-step heating reaction with a fourth polar solvent and optionally an auxiliary agent to prepare a scale and corrosion inhibitor;

[0035] More preferably, the fourth polar solvent includes at least one of absolute ethanol, deionized water, dimethyl sulfoxide, and N,N-dimethylformamide;

[0036] More preferably, the auxiliary agent includes at least one of potassium iodide, 2-methyl-3-butyn-2-ol, propargyl alcohol, and β-cyclodextrin;

[0037] More preferably, based on the mass of the product obtained by removing the solid precipitate from the product obtained in the second-step heating reaction being 100%, the mass of the polar solvent is more than 30%;

[0038] More preferably, based on the mass of the product obtained by removing the solid precipitate from the product obtained in the second-step heating reaction being 100%, the mass of the auxiliary agent is 5-15%.

[0039] The scale and corrosion inhibitor prepared by the preparation method of the scale and corrosion inhibitor provided by the present invention has water solubility, can be applied to sulfur-containing gas fields, and has excellent high-temperature resistance and anti-corrosion / scale formation performance.

[0040] The present invention provides a scale and corrosion inhibitor, which contains the compound for the scale and corrosion inhibitor provided by the present invention.

[0041] According to a specific embodiment of the present invention, preferably, the scale and corrosion inhibitor further includes a polar solvent;

[0042] More preferably, the polar solvent includes at least one of absolute ethanol, deionized water, dimethyl sulfoxide, and N,N-dimethylformamide;

[0043] According to a specific embodiment of the present invention, preferably, the scale and corrosion inhibitor further includes an auxiliary agent;

[0044] More preferably, the auxiliary agent includes at least one of potassium iodide, 2-methyl-3-butyn-2-ol, propargyl alcohol, and β-cyclodextrin.

[0045] In a specific embodiment of the present invention, there is provided a scale and corrosion inhibitor prepared by using the preparation method of the scale and corrosion inhibitor provided by the present invention.

[0046] The scale and corrosion inhibitor provided by the present invention has water solubility, can be applied to sulfur-containing gas fields, and has excellent high-temperature resistance and anti-corrosion / scale formation performance.

[0047] The present invention also provides the application of the above scale and corrosion inhibitor in the development of sulfur-containing gas fields.

[0048] According to the specific implementation embodiments of the present invention, preferably, the application environmental temperature of the scale and corrosion inhibitor is 0 - 180 °C.

[0049] The compound for the scale and corrosion inhibitor provided by the present invention has excellent water solubility, can be rapidly adsorbed on the metal surface, and is not easily denatured at high temperatures. The scale and corrosion inhibitor provided by the present invention contains the compound for the scale and corrosion inhibitor provided by the present invention, has excellent high-temperature resistance performance and mixed anti-corrosion / scale inhibition effect, and can effectively achieve the protection of electrochemical corrosion of downhole strings in sulfur-containing gas fields and reduce the scale formation amount. Compared with the prior art, it has the following beneficial effects:

[0050] 1. The scale and corrosion inhibitor provided by the present invention has good corrosion inhibition performance and can meet the corrosion inhibition efficiency requirements at extremely low dosages; for example, in some embodiments, at a dosage of 100 ppm and a temperature of 80 °C, the corrosion inhibition efficiency can still reach more than 98%.

[0051] 2. The scale and corrosion inhibitor provided by the present invention also has good corrosion inhibition performance under high-temperature conditions; for example, in some embodiments, at a dosage of 1500 ppm and a high temperature of 180 °C, the corrosion inhibition efficiency can still reach more than 93%.

[0052] 3. The scale and corrosion inhibitor provided by the present invention has good scale inhibition performance; for example, in some embodiments, at a dosage of 100 ppm, the scale inhibition efficiency can reach more than 98%.

[0053] 4. The scale and corrosion inhibitor provided by the present invention also has good scale inhibition performance under high-temperature conditions; for example, in some embodiments, at a dosage of 1500 ppm and a high temperature of 180 °C, the scale inhibition efficiency can still reach more than 81%. Description of the Drawings

[0054] Figure 1 It is the Fourier transform infrared spectroscopy characterization diagram of the intermediate product in Example 5 of the present invention.

[0055] Figure 2 It is the Fourier transform infrared spectroscopy characterization diagram of the final product in Example 5 of the present invention.

[0056] Figure 3 It is the nuclear magnetic resonance spectroscopy characterization diagram of the intermediate product in Example 5 of the present invention.

[0057] Figure 4 It is the nuclear magnetic resonance spectroscopy characterization diagram of the final product in Example 5 of the present invention.

[0058] Figure 5 It is the thermogravimetric analysis diagram of the final product in Examples 5 - 8 of the present invention. Detailed Implementation Modes

[0059] For a clearer understanding of the technical features, objectives, and beneficial effects of the present invention, the technical solution of the present invention will be described in detail below, but it should not be construed as a limitation on the implementable scope of the present invention.

[0060] Example 1

[0061] This example provides a scale and corrosion inhibitor, and its preparation method includes the following steps:

[0062] Add the reactants cinnamaldehyde, diethylenetriamine, and 1-acetylimidazole into the reaction vessel in a molar ratio of 1.0:0.5:1.0, add anhydrous ethanol with a volume three times that of the reactants to obtain a first mixture, adjust the pH of the first mixture to 2 using concentrated hydrochloric acid, continuously introduce nitrogen into the reaction vessel, and heat it stably at 70 °C for 4 hours to achieve the first heating reaction. After the reaction system cools down, rotary evaporate and concentrate the mixture at 50 °C until the solvent completely evaporates.

[0063] Add anhydrous ethanol (the mass of anhydrous ethanol is 10 times the mass of the product after rotary evaporation and filtration) to the product after rotary evaporation and concentration, then remove the solid precipitate, and then add ethyl acetate (the volume ratio of anhydrous ethanol to ethyl acetate is 1:5). After stirring and mixing, perform ice bath extraction to remove the excess reactants to obtain an intermediate product.

[0064] Mix deionized water, 2-hydroxy-3-chloropropyl phosphate sodium (HCP), and the intermediate product in a mass ratio of 100:0.5:5 to obtain a second mixture, heat the second mixture stably at 80 °C for 5 hours to achieve the second heating reaction, and filter to remove the solid precipitate in the solution to obtain the final product.

[0065] Add deionized water with a mass of 40% of the final product to the final product to obtain the scale and corrosion inhibitor.

[0066] In the first heating reaction:

[0067]

[0068] In the second heating reaction:

[0069]

[0070] The final product contains a scale and corrosion inhibitor compound with the following structural formula:

[0071]

[0072] Example 2

[0073] This embodiment provides a scale and corrosion inhibitor, and its preparation method includes the following steps:

[0074] Add the reactants cinnamaldehyde, tetraethylenepentamine, and 2-acetylthiazole into a reaction vessel in a molar ratio of 1.2:0.5:1.1, add anhydrous ethanol with a volume three times that of the reactants to obtain a first mixture, adjust the pH of the first mixture to 4 using concentrated hydrochloric acid, continuously introduce nitrogen into the reaction vessel, and heat it steadily at 80 °C for 6 hours to achieve the first heating reaction. After the reaction system cools down, rotary evaporate and concentrate the mixture at 50 °C until the solvent completely evaporates.

[0075] Add anhydrous ethanol (the mass of anhydrous ethanol is 10 times the mass of the product after rotary evaporation and filtration) to the product after rotary evaporation and concentration, then remove the solid precipitate, and then add ethyl acetate (the volume ratio of anhydrous ethanol to ethyl acetate is 1:5). After stirring and mixing, perform ice bath extraction to remove the excess reactants to obtain an intermediate product.

[0076] Mix deionized water, 2-hydroxy-3-chloropropyl phosphate sodium (HCP) and the intermediate product in a mass ratio of 100:0.5:10 to obtain a second mixture, heat the second mixture steadily at 80 °C for 5 hours to achieve the second heating reaction, and filter to remove the solid precipitate in the solution to obtain the final product.

[0077] Add deionized water accounting for 40% of the mass of the final product and 10% of potassium iodide additive to the final product to obtain the scale and corrosion inhibitor.

[0078] In the first heating reaction:

[0079]

[0080]

[0081] In the second heating reaction:

[0082]

[0083] The final product contains a scale and corrosion inhibitor compound with the following structural formula:

[0084]

[0085] Example 3

[0086] This embodiment provides a scale and corrosion inhibitor, and its preparation method includes the following steps:

[0087] The reactants cinnamaldehyde, tetraethylenepentamine, and 2-acetylthiazole were added to a reaction vessel in a molar ratio of 1.0:0.5:1.0, and anhydrous ethanol with a volume three times that of the reactants was added to obtain a first mixture. The pH of the first mixture was adjusted to 6 using concentrated hydrochloric acid. Nitrogen was continuously introduced into the reaction vessel, and the mixture was heated at 80 °C for 8 hours to achieve the first heating reaction. After the reaction system cooled, the mixture was rotary evaporated at 50 °C until the solvent completely evaporated.

[0088] Anhydrous ethanol (the mass of anhydrous ethanol was 10 times the mass of the product after rotary evaporation and filtration) was added to the product after rotary evaporation and concentration, and then the solid precipitate was removed. Ethyl acetate (the volume ratio of anhydrous ethanol to ethyl acetate was 1:5) was added, and after stirring and mixing, it was extracted in an ice bath to remove the excess reactants, obtaining an intermediate product.

[0089] Deionized water, 2-hydroxy-3-chloropropyl phosphate sodium (HCP), and the intermediate product were mixed in a mass ratio of 100:0.5:10 to obtain a second mixture. The second mixture was heated at 80 °C for 5 hours to achieve the second heating reaction, and the solid precipitate in the solution was removed by filtration to obtain the final product.

[0090] Deionized water with a mass of 40% of the final product and 10% of propargyl alcohol auxiliary were added to the final product to obtain a scale and corrosion inhibitor.

[0091] In the first heating reaction:

[0092]

[0093]

[0094] In the second heating reaction:

[0095]

[0096] The final product contains a scale and corrosion inhibitor compound with the following structural formula:

[0097]

[0098] Example 4

[0099] This example provides a scale and corrosion inhibitor, and its preparation method includes the following steps:

[0100] The reactants cinnamaldehyde, tetraethylenepentamine, and 3-acetylpyridine were added to a reaction vessel in a molar ratio of 1.2:0.5:1.1. Anhydrous ethanol with a volume three times that of the reactants was added to obtain a first mixture. The pH of the first mixture was adjusted to 4 using concentrated hydrochloric acid. Nitrogen was continuously introduced into the reaction vessel, and the mixture was heated at 80 °C for 6 hours to achieve the first heating reaction. After the reaction system cooled, the mixture was rotary evaporated at 50 °C until the solvent completely evaporated.

[0101] Anhydrous ethanol (the mass of anhydrous ethanol was 10 times the mass of the product after rotary evaporation and filtration) was added to the product after rotary evaporation and concentration. Then, the solid precipitate was removed. Ethyl acetate (the volume ratio of anhydrous ethanol to ethyl acetate was 1:5) was added, and after stirring and mixing, it was extracted in an ice bath to remove the excess reactants, obtaining an intermediate product.

[0102] Deionized water, 2-hydroxy-3-chloropropyl phosphate sodium (HCP), and the intermediate product were mixed in a mass ratio of 100:0.5:10 to obtain a second mixture. The second mixture was heated at 90 °C for 5 hours to achieve the second heating reaction. The solid precipitate in the solution was removed by filtration to obtain the final product.

[0103] Deionized water with a mass of 40% of the final product and 10% of the β-cyclodextrin additive were added to the final product to obtain the scale and corrosion inhibitor.

[0104] In the first heating reaction:

[0105]

[0106]

[0107] In the second heating reaction:

[0108]

[0109] The final product contains a compound for scale and corrosion inhibitor with the following structural formula:

[0110]

[0111] Example 5

[0112] This example provides a scale and corrosion inhibitor, and its preparation method includes the following steps:

[0113] The reactants cinnamaldehyde, tetraethylenepentamine, and 2-acetylthiazole were added to a reaction vessel in a molar ratio of 1.0:0.5:1.0. Anhydrous ethanol with a volume three times that of the reactants was added to obtain a first mixture. The pH of the first mixture was adjusted to 4 using concentrated hydrochloric acid. Nitrogen was continuously introduced into the reaction vessel, and the mixture was heated at 80 °C for 6 hours to achieve the first heating reaction. After the reaction system cooled, the mixture was rotary evaporated at 50 °C until the solvent completely evaporated.

[0114] Anhydrous ethanol (the mass of anhydrous ethanol was 10 times the mass of the product after rotary evaporation and filtration) was added to the product after rotary evaporation and concentration. Then, the solid precipitate was removed. Ethyl acetate (the volume ratio of anhydrous ethanol to ethyl acetate was 1:5) was added, and after stirring and mixing, it was extracted in an ice bath to remove the excess reactants, obtaining an intermediate product.

[0115] Deionized water, 2-hydroxy-3-chloropropyl phosphate sodium (HCP), and the intermediate product were mixed in a mass ratio of 100:0.5:10 to obtain a second mixture. The second mixture was heated at 80 °C for 5 hours to achieve the second heating reaction. The solid precipitate in the solution was removed by filtration to obtain the final product.

[0116] Deionized water with a mass of 40% of the final product and 10% of the β-cyclodextrin additive were added to the final product to obtain the scale and corrosion inhibitor.

[0117] In the first heating reaction:

[0118]

[0119]

[0120] In the second heating reaction:

[0121]

[0122] The final product contains a compound for scale and corrosion inhibitor with the following structural formula:

[0123]

[0124] Example 6

[0125] This example provides a scale and corrosion inhibitor, and its preparation method includes the following steps:

[0126] The reactants benzaldehyde, tetraethylenepentamine, and 2-acetylthiazole were added to a reaction vessel in a molar ratio of 1.1:0.5:1.1. Anhydrous ethanol with a volume three times that of the reactants was added to obtain a first mixture. The pH of the first mixture was adjusted to 4 using concentrated hydrochloric acid. Nitrogen was continuously introduced into the reaction vessel, and the mixture was heated at 75 °C for 6 hours to achieve the first heating reaction. After the reaction system cooled, the mixture was rotary evaporated at 50 °C until the solvent completely evaporated.

[0127] Anhydrous ethanol (the mass of anhydrous ethanol was 10 times the mass of the product after rotary evaporation and filtration) was added to the product after rotary evaporation and concentration. Then, the solid precipitate was removed. Ethyl acetate (the volume ratio of anhydrous ethanol to ethyl acetate was 1:3) was added, and after stirring and mixing, it was extracted in an ice bath to remove the excess reactants, obtaining an intermediate product.

[0128] Deionized water, sodium 2-hydroxy-3-chloropropyl phosphate (HCP), and the intermediate product were mixed in a mass ratio of 100:0.5:10 to obtain a second mixture. The second mixture was heated at 80 °C for 5 hours to achieve the second heating reaction. The solid precipitate in the solution was removed by filtration to obtain the final product.

[0129] Deionized water accounting for 40% of the mass of the final product, 5% propargyl alcohol additive, and 5% β-cyclodextrin additive were added to the final product to obtain the scale and corrosion inhibitor.

[0130] In the first heating reaction:

[0131]

[0132]

[0133] In the second heating reaction:

[0134]

[0135] The final product contains a compound for scale and corrosion inhibitor with the following structural formula:

[0136]

[0137] Example 7

[0138] This example provides a scale and corrosion inhibitor, and its preparation method includes the following steps:

[0139] Add the reactants formaldehyde solution (aqueous formaldehyde solution with a formaldehyde mass concentration of 37%), tetraethylenepentamine, and 2-acetylthiazole to the reaction vessel in a molar ratio of formaldehyde:tetraethylenepentamine:2-acetylthiazole of 1.0:0.5:1.0. Add anhydrous ethanol with a volume three times that of the reactants to obtain a first mixture. Adjust the pH of the first mixture to 4 using concentrated hydrochloric acid. Continuously introduce nitrogen into the reaction vessel and heat it steadily at 90 °C for 6 hours to achieve the first heating reaction. After the reaction system cools down, rotary evaporate and concentrate the mixture at 50 °C until the solvent completely evaporates.

[0140] Add anhydrous ethanol (the mass of anhydrous ethanol is 10 times the mass of the product after rotary evaporation and filtration) to the product after rotary evaporation and concentration, then remove the solid precipitate. Add ethyl acetate (the volume ratio of anhydrous ethanol to ethyl acetate is 1:5), stir and mix, and then perform ice bath extraction to remove excess reactants to obtain an intermediate product.

[0141] Mix deionized water, 2-hydroxy-3-chloropropyl phosphate sodium (HCP) with the intermediate product in a mass ratio of 100:1:10 to obtain a second mixture. Heat the second mixture steadily at 80 °C for 5 hours to achieve the second heating reaction. Filter to remove the solid precipitate in the solution to obtain the final product.

[0142] Add deionized water accounting for 40% of the mass of the final product, 5% potassium iodide additive, and 5% β-cyclodextrin additive to the final product to obtain the scale and corrosion inhibitor.

[0143] In the first heating reaction:

[0144]

[0145] In the second heating reaction:

[0146]

[0147]

[0148] The final product contains a compound for scale and corrosion inhibitor with the following structural formula:

[0149]

[0150] Example 8

[0151] This example provides a scale and corrosion inhibitor, and its preparation method includes the following steps:

[0152] The reactants cinnamaldehyde, tetraethylenepentamine, and 2-acetylthiazole were added to a reaction vessel in a molar ratio of 1.2:0.5:1.2. Anhydrous ethanol with a volume three times that of the reactants was added to obtain a first mixture. The pH of the first mixture was adjusted to 6 using concentrated hydrochloric acid. Nitrogen was continuously introduced into the reaction vessel, and the mixture was heated at 80 °C for 10 hours to achieve the first heating reaction. After the reaction system cooled, the mixture was rotary evaporated at 50 °C until the solvent completely evaporated.

[0153] Dimethyl sulfoxide was added to the product after rotary evaporation and concentration (the mass of anhydrous ethanol was 10 times the mass of the product after rotary evaporation and filtration), and then the solid precipitate was removed. Ethyl acetate was added (the volume ratio of dimethyl sulfoxide to ethyl acetate was 1:5), and after stirring and mixing, it was extracted in an ice bath to remove the excess reactants, obtaining an intermediate product.

[0154] Dimethyl sulfoxide, sodium 2-hydroxy-3-chloropropyl phosphate (HCP), and the intermediate product were mixed in a mass ratio of 100:0.5:10 to obtain a second mixture. The second mixture was heated at 80 °C for 5 hours to achieve the second heating reaction, and the solid precipitate in the solution was removed by filtration to obtain the final product.

[0155] Dimethyl sulfoxide accounting for 40% of the mass of the final product, 5% potassium iodide additive, and 5% β-cyclodextrin additive were added to the final product to obtain the scale and corrosion inhibitor.

[0156] In the first heating reaction:

[0157]

[0158] In the second heating reaction:

[0159]

[0160]

[0161] The final product contains a compound for scale and corrosion inhibitor with the following structural formula:

[0162]

[0163] Example 9

[0164] This example provides a scale and corrosion inhibitor, and its preparation method includes the following steps:

[0165] The reactants cinnamaldehyde, tetraethylenepentamine, and 2-acetylthiazole were added to a reaction vessel in a molar ratio of 1.2:0.5:1.2. Anhydrous ethanol with a volume three times that of the reactants was added to obtain a first mixture. The pH of the first mixture was adjusted to 6 using concentrated hydrochloric acid. Nitrogen was continuously introduced into the reaction vessel, and the mixture was heated at 80 °C for 10 hours to achieve the first heating reaction. After the reaction system cooled, the mixture was rotary evaporated at 50 °C until the solvent completely evaporated.

[0166] Dimethyl sulfoxide was added to the product after rotary evaporation and concentration (the mass of anhydrous ethanol was 10 times the mass of the product after rotary evaporation and filtration), and then the solid precipitate was removed. Ethyl acetate was added (the volume ratio of dimethyl sulfoxide to ethyl acetate was 1:5), and after stirring and mixing, it was extracted in an ice bath to remove the excess reactants, obtaining an intermediate product.

[0167] Dimethyl sulfoxide, 2-hydroxy-3-chloropropyl sodium phosphate (HCP), and the intermediate product were mixed in a mass ratio of 100:0.5:10 to obtain a second mixture. The second mixture was heated at 80 °C for 5 hours to achieve the second heating reaction. The solid precipitate in the solution was removed by filtration to obtain the final product.

[0168] Dimethyl sulfoxide accounting for 40% of the mass of the final product, 5% of the 2-methyl-3-butyn-2-ol auxiliary agent, and 5% of the β-cyclodextrin auxiliary agent were added to the final product to obtain the scale and corrosion inhibitor.

[0169] In the first heating reaction:

[0170]

[0171] In the second heating reaction:

[0172]

[0173]

[0174] The final product contains a compound for the scale and corrosion inhibitor with the following structural formula:

[0175]

[0176] Product performance detection test:

[0177] Test example 1:

[0178] The scale and corrosion inhibition performance of the scale and corrosion inhibitors provided in Examples 1 - 8 was tested under normal pressure.

[0179] The specific test process is as follows: The scale and corrosion inhibitors provided in Examples 1-8 were respectively subjected to corrosion tests on water samples containing H2S and CO2. The corrosion experiment process was carried out with reference to Section 3, "Determination Method of Atmospheric Static Corrosion Rate and Corrosion Inhibition Rate", of the Petroleum Industry Standard SY / T 5273-2000 "Evaluation Method of Corrosion Inhibitors for Produced Water in Oilfields". Among them, the material of the test piece is the BG110SS seamless steel pipe material used for wellbore tubing. The corrosion test medium is an aqueous solution containing 50,000 ppm NaCl, 1,000 ppm H2S, and 300 ppm CO2. The use concentration of the scale and corrosion inhibitor is 100 ppm (calculated based on the total mass of the corrosion test medium being 100%). The temperature environment is 80 °C, and the oxygen environment is anaerobic. After corrosion for 72 h under the above conditions, the corrosion rate r corr and the corrosion inhibition rate η were determined according to the mass difference of the test piece before and after the test.

[0180] Among them, the annual corrosion rate r corr is determined by the following formula:

[0181]

[0182] In the formula: r corr is the uniform corrosion rate, with the unit of millimeters per year (mm / a); Δm is the weight loss of the hanging piece, with the unit of grams (g); s is the exposed area of the hanging piece, with the unit of square centimeters (cm 2 ); t is the experimental time, with the unit of hours (h); ρ is the relative density of the hanging piece, with the unit of grams per cubic centimeter (g / cm 3 ).

[0183] Among them, the corrosion inhibition rate η is determined by the following formula:

[0184]

[0185] In the formula: η is the corrosion inhibition rate, %; Δm0 is the weight loss of the hanging piece in the blank test, with the unit of grams (g); Δm1 is the weight loss of the hanging piece after adding the corrosion inhibitor, with the unit of grams (g).

[0186] The corrosion inhibition rates of the samples of the scale and corrosion inhibitors provided in Examples 1-8 were statistically analyzed, and the results are shown in Table 1:

[0187] Table 1

[0188] Example Temperature / °C Corrosion Inhibition Rate / % Blank 80 — 1 80 84.7 2 80 97.1 3 80 92.6 4 80 90.4 5 80 97.6 6 80 93.1 7 80 88.2 8 80 98.0 9 80 92.8

[0189] As can be seen from Table 1, the scale and corrosion inhibitor provided by the present invention has good corrosion inhibition performance at 80 °C, and the corrosion inhibition efficiency can reach more than 80%. In better examples, the corrosion inhibition efficiency can reach 98%.

[0190] Test Example 2:

[0191] The corrosion inhibition performance of the scale and corrosion inhibitors provided in Examples 1 - 8 was tested under high temperature and high pressure.

[0192] The specific test process was as follows: The scale and corrosion inhibitors provided in Examples 1 - 8 were respectively subjected to corrosion tests in a high temperature and high pressure environment containing H2S and CO2. The corrosion experiment process was carried out with reference to the American Society for Testing and Materials standard ASTM G111 "Standard Guide for Corrosion Tests in High Temperature or High Pressure Environment, or Both". Among them, the material of the test piece was the BG110SS seamless steel pipe material used for wellbore tubing. The corrosion test medium was an aqueous solution containing 50000 ppm NaCl, 1000 ppm H2S, and 300 ppm CO2. The use concentration of the scale and corrosion inhibitor was 1500 ppm (calculated based on the total mass of the corrosion test medium being 100%). The partial pressure of H2S was 0.5 MPa, the partial pressure of CO2 was 3.0 MPa, the total pressure was 10 MPa, the temperature environment was 180 °C, and the oxygen environment was anoxic. After corrosion for 72 h under the above conditions, the corrosion inhibition rate η was determined according to the method of Test Example 1.

[0193] The corrosion inhibition rates of the samples of the scale and corrosion inhibitors provided in Examples 1 - 8 under high temperature and high pressure were statistically analyzed, and the results are shown in Table 2:

[0194] Table 2

[0195] Example Temperature / °C Corrosion Inhibition Rate / % Blank 180 — 1 180 46.2 2 180 74.8 3 180 76.2 4 180 67.5 5 180 93.3 6 180 82.4 7 180 87.5 8 180 92.5 9 180 79.9

[0196] As can be seen from Table 2, the scale and corrosion inhibitor provided by the present invention has good corrosion inhibition performance at a high temperature of 180 °C, and the corrosion inhibition efficiency can reach more than 45%. In better examples, the corrosion inhibition efficiency can reach more than 93%.

[0197] Test Example 3:

[0198] The scale inhibition performance of the scale and corrosion inhibitors provided in Examples 1 - 8 was tested.

[0199] The specific test process was as follows: The static scale inhibition experiment was used to evaluate the scale inhibition performance of the scale and corrosion inhibitors provided in Examples 1 - 8. The static scale inhibition experiment process was carried out with reference to the static scale inhibition experiment process in accordance with Section A.3.3 "Scale Inhibition Rate of CaCO3 Scale" of the PetroChina Enterprise Standard Q / SY 126 - 2014 "Technical Specification for Corrosion Inhibitors and Scale Inhibitors for Oilfield Water Treatment". Among them, the use concentration of the scale and corrosion inhibitor was 100 ppm, and the calcium ion content was determined by the EDTA titration method.

[0200] The scale inhibition performance was expressed by the scale inhibition rate X (%), and was determined according to the following formula:

[0201]

[0202] Wherein: V1 is the volume of the EDTA standard solution consumed after adding the scale inhibitor, in milliliters (mL); V0 is the volume of the EDTA standard solution consumed for titrating the blank sample solution 1, in milliliters (mL); V is the volume of the EDTA standard solution consumed for titrating the blank sample solution 2, in milliliters (mL);

[0203] The scale inhibition rates of the samples of the scale and corrosion inhibitors provided in Examples 1 - 8 were statistically analyzed, and the results are shown in Table 3 as follows:

[0204] Table 3

[0205] Example Temperature / °C Scale Inhibition Rate / % Blank Sample 1 50 — Blank Sample 2 50 — 1 50 91.1 2 50 97.4 3 50 96.5 4 50 97.2 5 50 95.3 6 50 98.1 7 50 92.3 8 50 94.6 9 50 95.0

[0206] It can be seen from Table 3 that the scale and corrosion inhibitor provided by the present invention has good scale inhibition performance, and the scale inhibition efficiency can reach more than 90%, and in better examples, the scale inhibition efficiency can reach more than 98%.

[0207] Test Example 4:

[0208] The scale inhibition performance of the scale and corrosion inhibitors provided in Examples 1 - 8 was tested at a high temperature of 180°C.

[0209] The specific test process is as follows: The static scale inhibition experiment was used to evaluate the scale inhibition performance of the scale and corrosion inhibitors provided in Examples 1 - 8 at a high temperature of 180°C. The process of the static scale inhibition experiment was carried out with reference to the process of the static scale inhibition experiment in accordance with Section A.3.3 "Scale Inhibition Rate of CaCO3 Scale" of the Technical Specification for Corrosion and Scale Inhibitors for Oilfield Water Treatment Q / SY 126 - 2014 of PetroChina Enterprise Standard; among them, when performing step a) of Section 3.3.1, the following adjustments were made, specifically as follows: Take 200 mL of distilled water in a 250 mL volumetric flask, accurately add 6.00 mL of CaCl solution, accurately add 7.5 mL of the scale and corrosion inhibitor solution, let it stand for 10 min, then add 6.00 mL of Na2CO3 solution drop by drop while shaking, dilute to the scale with distilled water, shake well, put the above solution into a 500 mL hydrothermal reaction kettle, cover the sealing cover, place it in a water bath at 50°C ± 1°C, keep it at a constant temperature for half an hour, open the bottle cap to release gas after the temperature is balanced, then tighten the bottle cap again, and let it stand in an oven at 180°C ± 5°C for 16 h.

[0210] Among them, the use concentration of the scale and corrosion inhibitor is 1500 ppm, and the calcium ion content is determined by the EDTA titration method.

[0211] The scale inhibition performance is expressed by the scale inhibition rate X (%), and is determined according to the following formula:

[0212]

[0213] Where: V1 is the volume of the EDTA standard solution consumed after adding the scale inhibitor, in milliliters (mL); V0 is the volume of the EDTA standard solution consumed for titrating the blank 1 sample solution, in milliliters (mL); V is the volume of the EDTA standard solution consumed for titrating the blank 2 sample solution, in milliliters (mL).

[0214] The scale inhibition rates of the samples of the scale and corrosion inhibitors provided in Examples 1 - 8 were statistically analyzed, and the results are shown in Table 4 as follows:

[0215] Table 4

[0216] Example Temperature / °C Scale Inhibition Rate / % Blank Sample 1 180 — Blank Sample 2 180 — 1 180 52.1 2 180 71.6 3 180 69.1 4 180 78.2 5 180 79.0 6 180 81.3 7 180 73.3 8 180 78.9 9 180 77.8

[0217] As can be seen from Table 4, the scale and corrosion inhibitor provided by the present invention has good scale inhibition performance at high temperatures. At 180 °C, in the better examples, the scale inhibition efficiency can reach 81.3%.

[0218] Test Example 5:

[0219] The intermediate product and the final product in Example 5 were respectively characterized by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy, and the results are as Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 shown.

[0220] Figure 1 It is the Fourier transform infrared spectroscopy characterization diagram of the intermediate product in Example 5. Figure 1 Among them, the small and sharp absorption peaks at 1300.15 cm -1 , 1349.97 cm -1 , and 1384.29 cm -1 are attributed to the stretching vibration of the C-H bond in the alkyl group. The small and sharp peak at 1492.48 cm -1 is attributed to the deformation vibration of the C-N bond. The strong absorption peak near 1598.2 cm -1 is attributed to the stretching vibration of N-H. The absorption peak at 762.49 cm -1 is attributed to the stretching vibration peak of C-S. 700.61 cm -1 is attributed to the out-of-plane bending vibration of the phenyl C-H bond. The stretching vibration peak of the carbonyl C=O is located at 1690 cm -1 -1750 cm -1 , which merges with the characteristic peak of N-H into a broad and strong peak. The broad frequency absorption band at 2819.31 cm -1 is attributed to the torsional vibration of C=N. The broad frequency strong absorption band at 3411.81 cm -1 is attributed to the stretching vibration of O-H. Figure 31H NMR spectrum characterization diagram of the intermediate in Example 5. Figure 3 In Figure 3 , 1H NMR (DMSO, 400 MHz), the proton peak of secondary amine -NH is at 1.83 ppm, the proton peaks of methylene in -NH-CH2-CH2-NH- are at chemical shifts of 2.65 ppm and 2.67 ppm, the proton peaks on the phenyl are at 7.23 ppm - 7.31 ppm, the proton peaks of -CH=CH- on the thiazole ring are at chemical shifts of 8.14 ppm - 8.21 ppm, the chemical shift of -CH=CH- connected to the phenyl is at 6.5 ppm, and the proton peaks of methine are at chemical shifts of 3.41 ppm - 3.45 ppm.

[0221] Figure 2 Fourier transform infrared spectrum characterization diagram of the final product in Example 5. Figure 2 In Figure 2 , the small and sharp absorption peaks at 1294.32 cm -1 、1351.98 cm -1 、1384.40 cm -1 are attributed to the stretching vibration of C-H bonds in alkyl groups, the small and sharp peak at 1493.48 cm -1 is attributed to the deformation vibration of C-N bonds, the strong absorption peak near 1599.38 cm -1 is attributed to the stretching vibration of N-H, the absorption peak at 765.14 cm -1 is attributed to the stretching vibration peak of C-S, the absorption peak at 702.17 cm -1 is attributed to the out-of-plane bending vibration of phenyl C-H bonds, the stretching vibration peak of carbonyl C=O is at 1690 - 1750 cm -1 , which merges with the characteristic peak of N-H into a broad and strong peak, the broadband absorption band at 2800 cm -1 is attributed to the torsional vibration of C=N, and the peak becomes weak due to the quaternization reaction, the broadband strong absorption band at 3414.56 cm -1 is attributed to the stretching vibration of O-H. The characteristic absorption peak at 1080.84 cm -1 is attributed to the introduction of P=O stretching vibration, the absorption at 937.24 cm -1 is attributed to the introduced P-O-C bending vibration, the C-Cl absorption peak at 873.55 cm -1 is almost invisible, attributed to the conversion of C-Cl bonds to C-N bonds due to the quaternization reaction. Figure 4 1H NMR spectrum characterization diagram of the final product in Example 5. Figure 4Among them, 1H NMR (DMSO, 400 MHz): the chemical shift at 1.23 ppm is the proton peak of -N-CH2-C- introduced into HCP; the chemical shift at 1.84 ppm is the proton peak of secondary amine -NH; the chemical shift at 1.91 ppm is the proton peak of -OH introduced into HCP; the chemical shifts at 2.64 ppm - 2.88 ppm are the proton peaks of methylene in -NH-CH2-CH2-NH-; the chemical shifts at 3.01 ppm - 3.38 ppm are the proton peaks of methine; the chemical shift at 6.52 ppm is the proton peak of -CH=CH-; the chemical shifts at 7.32 ppm - 7.42 ppm are the proton peaks on the phenyl group; the chemical shifts at 7.66 ppm - 7.68 ppm are the proton peaks of -CH=CH- on the thiazole ring.

[0222] Thermogravimetric analysis was performed on the final products in Examples 5 - 8, and the results are as Figure 5 shown. In Example 7, obvious weight loss occurred at 190 °C, attributed to the thermal decomposition reaction of the compound, and obvious weight loss occurred again at 270 °C, attributed to the secondary thermal decomposition of the sample; in Example 5, obvious weight loss occurred at 268 °C, attributed to the thermal decomposition reaction of the compound; in Example 6, obvious weight loss occurred at 249 °C, attributed to the thermal decomposition reaction of the compound; in Example 8, obvious weight loss occurred at 266 °C, attributed to the thermal decomposition reaction of the compound. Thermal analysis shows that the final products in Examples 5 - 8 have excellent thermal stability.

[0223] Thus, specific embodiments of the subject matter have been described. Other embodiments are within the scope of the appended claims. In some cases, the acts recited in the claims can be performed in a different order and still achieve the desired result. Additionally, the processes depicted in the figures are not necessarily in the particular order or sequential order shown to achieve the desired result.

Claims

1. A compound for scale and corrosion inhibitor, which has the structure shown in Formula I:

2. The compound for scale and corrosion inhibitor according to claim 1, wherein R1 is selected from one of substituted or unsubstituted alkyl, aminoalkyl; Preferably, R1 is selected from one of them.

3. The compound for scale and corrosion inhibitor according to claim 1, wherein, R2 is selected from one of H and substituted or unsubstituted aryl; Preferably, R2 is selected from one of them.

4. The compound for scale and corrosion inhibitor according to claim 1, wherein R3 is selected from substituted or unsubstituted five - or six - membered heterocyclic rings containing heteroatoms; Preferably, R3 is selected from one of them.

5. A preparation method of a scale and corrosion inhibitor, which comprises the following steps: Mix aldehyde, polyamine, ketone and a first polar solvent to obtain a first mixture; wherein, the molar ratio of aldehyde, polyamine, ketone is 1.0 - 1.2:0.5:1.0 - 1.2; the volume of the first polar solvent is 3 - 5 times the total volume of aldehyde, polyamine and ketone; Adjust the pH of the first mixture to 2 - 6, then carry out the first heating reaction under the protection of inert gas, and carry out the first purification treatment on the product obtained from the first heating reaction to remove the remaining reactants to obtain an intermediate product; Mix a second polar solvent, sodium 2 - hydroxy - 3 - chloropropyl phosphate and the intermediate product to obtain a second mixture; wherein, the mass ratio of the second polar solvent, sodium 2 - hydroxy - 3 - chloropropyl phosphate and the intermediate product is 100:0.5 - 1:5 - 10; Carry out the second heating reaction on the second mixture, and remove the solid precipitate in the product obtained from the second heating reaction, thereby preparing the scale and corrosion inhibitor.

6. According to the preparation method described in claim 5, wherein, The polyamine includes at least one of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine; and / or The aldehyde includes one of cinnamaldehyde, formaldehyde and benzaldehyde; and / or The ketone includes one of 2 - acetylthiazole, 1 - acetylimidazole and 3 - acetylpyridine.

7. According to the preparation method described in claim 5, wherein, The first solvent includes at least one of absolute ethanol, deionized water, dimethyl sulfoxide, N,N - dimethylformamide; and / or The second polar solvent includes at least one of absolute ethanol, deionized water, dimethyl sulfoxide, N,N - dimethylformamide.

8. The preparation method according to claim 5, wherein The reagent used for pH adjustment of the first mixture is hydrochloric acid; preferably, based on the mass of hydrochloric acid being 100%, the mass concentration of HCl in hydrochloric acid is 5 - 20%.

9. According to the preparation method described in claim 5, wherein, The temperature of the first heating reaction is 70 - 100 °C; The time of the first heating reaction is 4 - 10 h.

10. According to the preparation method described in claim 5, wherein, The temperature of the second heating reaction is 75 - 95 °C; The time of the second heating reaction is 5 - 24 h.

11. The preparation method according to claim 5, wherein, Carrying out the first purification treatment on the product obtained from the first heating reaction includes: rotary evaporation and concentration of the product obtained from the first heating reaction until the solvent completely volatilizes, and then using a third polar solvent and an anti - solvent to remove the remaining reactants; wherein, the volume ratio of the solvent and the anti - solvent is 1:2 - 5; Preferably, the third polar solvent includes at least one of absolute ethanol, deionized water, dimethyl sulfoxide, N,N - dimethylformamide; Preferably, the anti - solvent includes at least one of ether, ethyl acetate, methyl acetate, acetone; Preferably, the ratio of the mass of the product after rotary evaporation and concentration until the solvent is completely volatilized to the mass of the third polar solvent is 1:5 - 15; Preferably, using the third polar solvent and the anti-solvent to remove the remaining reactants includes: adding the third polar solvent, then removing the solid precipitate, and then adding the anti-solvent, stirring and mixing, and extracting with ice bath to remove the remaining reactants.

12. The preparation method according to claim 5, wherein, This method further includes: Mixing the product obtained by removing the solid precipitate from the product obtained in the second step of the heating reaction with a fourth polar solvent and optionally an auxiliary agent to prepare a scale and corrosion inhibitor; Preferably, the fourth polar solvent includes at least one of absolute ethanol, deionized water, dimethyl sulfoxide, and N,N-dimethylformamide; Preferably, the auxiliary agent includes at least one of potassium iodide, 2-methyl-3-butyn-2-ol, propargyl alcohol, and β-cyclodextrin; Preferably, based on the mass of the product obtained by removing the solid precipitate from the product obtained in the second step of the heating reaction being 100%, the mass of the polar solvent is more than 30%; Preferably, based on the mass of the product obtained by removing the solid precipitate from the product obtained in the second step of the heating reaction being 100%, the mass of the auxiliary agent is 5 - 15%.

13. A scale and corrosion inhibitor, which contains the compound for scale and corrosion inhibitor according to any one of claims 1 - 4.

14. The scale and corrosion inhibitor according to claim 13, wherein, This scale and corrosion inhibitor further includes a polar solvent; Preferably, the fourth polar solvent includes at least one of absolute ethanol, deionized water, dimethyl sulfoxide, and N,N-dimethylformamide.

15. The scale and corrosion inhibitor according to claim 13, wherein, This scale and corrosion inhibitor further includes an auxiliary agent; Preferably, the auxiliary agent includes at least one of potassium iodide, 2-methyl-3-butyn-2-ol, propargyl alcohol, and β-cyclodextrin.

16. The scale and corrosion inhibitor according to claim 13, wherein, This scale and corrosion inhibitor is prepared by using the preparation method of the scale and corrosion inhibitor according to any one of claims 11 - 13.

17. The application of the scale and corrosion inhibitor according to any one of claims 13 - 16 in the development of sulfur-containing gas fields; Preferably, the application environment temperature of the scale and corrosion inhibitor is 0 - 180°C.

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