Preparation method of high-temperature-resistant corrosion inhibitor for inhibiting multiple corrosion factors

Abstract

The invention discloses a preparation method of a high-temperature-resistant corrosion inhibitor for inhibiting multiple corrosion factors, which comprises the following steps: step 1, adding 3-5g of deoxidant into a 100mL beaker, adding 20mL of tap water, stirring for 10-20 minutes at the rotating speed of 400r / min until the deoxidant is uniformly dissolved, and standing aside for later use; 2, 15-25 g of phenylalanine imidazoline erucamide is added into a beaker with the volume of 250 mL, 10-15 g of triazinyl polyether bithiophene imidazoline, 1-3 g of polyglycerol fatty acid ester and 40-70 mL of tap water are added, stirring is conducted for 15-20 min at the rotating speed of 500 r / min, and the mixture is placed aside for use; slowly adding the solution in the step 1 into the solution in the step 2, and continuously stirring for 20-30 minutes at the rotating speed of 400r / min to obtain a final product. The corrosion inhibition effect in a multi-factor corrosion environment is improved.

Description

Technical Field

[0001] The invention relates to the technical field of petroleum exploitation, in particular to a method for preparing a high temperature corrosion inhibitor capable of suppressing multiple corrosion factors. Background Art

[0002] In the middle and late stages of oilfield development, as the degree of recovery increases, the water content of the formation continues to rise, and the number of oil wells with corrosion is also on the rise. In oil and gas production, CO2 and H2S are often associated corrosive gases. In the coexistence system of H2S and CO2, the two gases interact with each other. Even low concentrations of H2S will have a significant impact on CO2 corrosion, which can change the composition of corrosion products, thereby increasing the risk of corrosion, promoting local corrosion, and seriously affecting the reliability and service life of oil and gas field gathering and transportation systems. In addition, Cl - , Ca 2+ Mg 2+ Plasma, dissolved oxygen in the produced fluid, and sulfate-reducing bacteria will accelerate local corrosion. Due to the numerous corrosion influencing factors and the complex corrosion environment system at the oil and gas field development site, serious damage will be caused to the pipeline, and even unpredictable corrosion results will be caused.

[0003] In view of the corrosion of oil and gas fields caused by multiple factors such as CO2, H2S, O2, and SRB bacteria, the main anti-corrosion methods are the use of high-nickel-based alloy steel, coatings, and corrosion inhibitors. Among them, the use of high-nickel-based alloy steel is expensive and increases the cost of oil field development, and the main problem of coatings is that the use conditions are limited and they are easy to fall off. Adding corrosion inhibitors is a simple, effective, and inexpensive chemical anti-corrosion method in metal corrosion protection, and is widely used in oil extraction and gathering and transportation processes.

[0004] At present, the corrosion inhibition effect of conventional corrosion inhibitors is not ideal in an environment where multiple corrosive factors coexist, such as multiple corrosive gases, high concentrations of sulfate-reducing bacteria, high mineralization, high temperature and high pressure. It is particularly important to study an efficient corrosion inhibitor that can inhibit multiple corrosion factors.

[0005] Therefore, in order to solve the above problems, a method for preparing a high-temperature corrosion inhibitor that inhibits multiple corrosion factors is proposed. Edible green raw materials phenylalanine and erucic acid are selected, and imidazoline is modified by introducing benzene rings and long alkyl carbon chains to obtain non-toxic imidazoline amide to improve the hydrophobic shielding ability. The desulfurization, sterilization and high temperature and high pressure resistance capabilities are improved by introducing triazine groups to synthesize thiophene imidazoline. Finally, deoxidizers and non-ionic surfactants are added for compounding to further improve the antioxidant and corrosion inhibition properties. Summary of the invention

[0006] The object of the present invention is to provide a method for preparing a high temperature corrosion inhibitor for inhibiting multiple corrosion factors, the preparation method comprising the following steps:

[0007] Step 1: Add 3-5g of deoxidizer into a 100mL beaker, the deoxidizer is one of sodium thiosulfate or sodium bisulfite, add 20mL of tap water, stir at 400r / min for 10-20min until dissolved evenly, and set aside for use;

[0008] Step 2: Add 15-25g of phenylalanine imidazoline erucic acid amide into a 250mL beaker, add 10-15g of triazine polyether bithiphene imidazoline, 1-3g of polyglycerol fatty acid ester and 40-70mL of tap water respectively, wherein the polyglycerol fatty acid ester is one of decapolyglycerol oleate or decapolyglycerol stearate, stir at a speed of 500r / min for 15-20min, and set aside for use;

[0009] The preparation method of the phenylalanine imidazoline erucic acid amide is:

[0010] Step 21: Weigh 15-20 g of phenylalanine, 25-35 mL of tetraethylenepentamine, and 15-25 mL of water-carrying agent xylene in sequence, add them into a three-necked flask, install a reflux condenser, heat to 110-130° C. while stirring, react for 4-5 hours, and separate the large amount of water generated from the reaction system;

[0011] Step 22: Continue to raise the temperature to 210-230°C and react for 3-4 hours to obtain a crude product;

[0012] Step 23: The crude product is transferred to a distillation flask, and is subjected to rotary evaporation using a rotary evaporator to remove excess water and solvent xylene to obtain a crude phenylalanine imidazoline product;

[0013] Step 24: Dissolve 25-35 mL of erucic acid in 25-35 mL of ethanol, transfer all the crude phenylalanine imidazoline product in step 23 into a four-necked flask, add 15-25 mL of water-carrying agent xylene, heat to 120-140° C. under stirring, turn on the reflux condenser, slowly drop erucic acid into the four-necked flask from the dropping funnel, and react for 1.5-3 hours to obtain a white viscous liquid;

[0014] Step 25: The liquid product is transferred to a distillation flask, and is subjected to rotary evaporation using a rotary evaporator to remove excess water and solvent xylene to obtain phenylalanine imidazoline erucamide.

[0015] The preparation method of the triazine-based polyether bithiphene imidazoline:

[0016] Step 26: Weigh 8-12 g of 2-thiophenecarboxylic acid, 15-25 mL of tetraethylenepentamine, and 15-25 mL of water-carrying agent xylene, add them into a three-necked flask, install a reflux condenser, heat to 110-130° C. under stirring, react for 4-5 hours, and separate the large amount of water generated from the reaction system;

[0017] Step 27: Continue to raise the temperature to 210-230° C., react for 3-4 hours to obtain a crude product, transfer the crude product to a distillation flask, and use a rotary evaporator to remove excess water and solvent xylene to obtain a crude thiophene imidazoline product;

[0018] Step 28: Place 1.5-3.0 g of cyanuric chloride and 20-30 mL of acetone into a four-necked flask, place in a cooling water bath, maintain the temperature at 0-5°C and stir to make it dissolve evenly, dissolve 3-5 g of polyethylene glycol methyl ether 500 in 15-20 mL of acetone, slowly add dropwise into the flask using a dropping funnel, and stir and react at low temperature for 2-3 hours;

[0019] Step 29: Raise the temperature to 40-50°C, slowly add 5-7 g of thiophene imidazoline dissolved in 10 mL of acetone into the flask through a dropping funnel, and react for 3-4 hours under stirring; turn on the reflux condenser, raise the temperature to 90-105°C, adjust the pH to 7-8 with sodium carbonate, dissolve 3-5 g of polyethylene glycol methyl ether 500 in 15-20 mL of acetone, and slowly add dropwise into the flask with a dropping funnel, and react for 5-6 hours;

[0020] Step 210: The liquid product is transferred to a distillation flask, acetone is removed by vacuum distillation, and the obtained crude product is dissolved in dichloromethane, and allowed to stand to separate into layers, and the upper clear liquid is taken and vacuum distilled again to obtain a white viscous liquid triazine polyether bithiphene imidazoline.

[0021] Step 3: Slowly add the solution in step 1 to the solution in step 2, and continue stirring at 400 r / min for 20-30 min to obtain the final product.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The innovation of the present invention lies in the synthesis and compounding of multi-component imidazoline derivatives, the synthesis of green and environmentally friendly phenylalanine imidazoline erucic acid amide to improve water solubility, the introduction of triazine groups to synthesize bithiphene imidazoline, the improvement of sulfur removal, sterilization and temperature and salt resistance, and the compounding of the two with deoxidizers and non-ionic surfactants to further improve the corrosion inhibition effect in a multi-factor corrosion environment.

[0024] 2. The phenylalanine imidazoline erucic acid amide synthesized by the present invention is prepared by a two-step method by introducing the green raw material phenylalanine containing a benzene ring and the long-chain erucic acid extracted from rapeseed oil. The introduction of the benzene ring structure or the extension of the alkyl carbon chain can improve the water solubility, maintain the effectiveness of the adsorption film for a long time, and improve the corrosion inhibition effect.

[0025] 3. The triazine-based polyether bithiophene imidazoline synthesized by the present invention introduces a triazine group to improve the desulfurization and sterilization capabilities. The bithiophene imidazoline structure improves the high temperature and high pressure resistance of the corrosion inhibitor through double thiophene rings and imidazoline rings.

[0026] 4. The present invention introduces a reducing agent, namely sodium thiosulfate or sodium bisulfite, and utilizes the reducing agent to undergo a redox reaction with oxygen to achieve a deoxygenation effect.

[0027] 5. The present invention introduces nonionic surfactant polyglycerol fatty acid ester or compound, and utilizes its more hydrophilic hydroxyl groups and good emulsification and dispersion effects to further improve the water solubility and stability of the product in an acidic environment, thereby improving the corrosion inhibition effect in a multi-factor complex corrosion environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The molecular structural formula of phenylalanine imidazoline erucic acid amide of the present invention;

[0029] Figure 2 The molecular structure formula of the triazine-based polyether bithiophene imidazoline of the present invention is;

[0030] Figure 3 It is a structural schematic diagram of infrared spectrum detection of the present invention;

[0031] Figure 4 2 is a schematic diagram of the water quality detection structure of Experimental Example 2 of the present invention;

[0032] Figure 5 It is a graph showing the evaluation results of Test Example 2 of the present invention. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Embodiment 1:

[0035] 1. Preparation method of high temperature corrosion inhibitor:

[0036] Step 1: Add 4g sodium thiosulfate into a 100mL beaker, add 20mL tap water, and stir at 400r / min for 15min until it is evenly dissolved;

[0037] Step 2: Add 14 g of phenylalanine imidazoline erucamide into a 250 mL beaker, add 14 g of triazine polyether bithiphene imidazoline, 2 g of decaglycerol oleate, and 46 mL of tap water, respectively, and stir at 500 r / min for 15 min;

[0038] Step 3: Slowly add the solution in step 1 to the solution in step 2, and continue stirring at 400 r / min for 20 min to obtain the final product.

[0039] 2. Preparation method of phenylalanine imidazoline erucic acid amide:

[0040] Step 21: Weigh 15.5 g of phenylalanine, 25 mL of tetraethylenepentamine, and 16 mL of water-carrying agent xylene, add them into a three-necked flask, install a reflux condenser, heat to 115° C. under stirring, react for 4 hours, and separate the large amount of water generated from the reaction system;

[0041] Step 22: Continue heating to 210°C and react for 3 hours to obtain a crude product;

[0042] Step 23: The crude product is transferred to a distillation flask, and is subjected to rotary evaporation using a rotary evaporator to remove excess water and solvent xylene to obtain a crude phenylalanine imidazoline product;

[0043] Step 24: Dissolve 27 mL of erucic acid in 28 mL of ethanol, transfer all the crude product in step 3 into a four-necked flask, add 20 mL of water-carrying agent xylene, raise the temperature to 125° C. under stirring, turn on the reflux condenser, slowly drop erucic acid into the four-necked flask from the dropping funnel, and react for 2 hours to obtain a white viscous liquid;

[0044] Step 25: The liquid product is transferred to a distillation flask, and is subjected to rotary evaporation using a rotary evaporator to remove excess water and solvent xylene to obtain phenylalanine imidazoline erucamide.

[0045] 3. Preparation method of triazine-based polyether bithiphene imidazoline:

[0046] Step 26: Weigh 8.5 g of 2-thiophenecarboxylic acid, 15 mL of tetraethylenepentamine, and 15 mL of water-carrying agent xylene, add them into a three-necked flask, install a reflux condenser, heat to 120° C. under stirring, react for 4.5 hours, and separate the large amount of water generated from the reaction system;

[0047] Step 27: Continue to raise the temperature to 220° C. and react for 3 hours to obtain a crude product, transfer the crude product to a distillation flask, and use a rotary evaporator to remove excess water and solvent xylene to obtain a crude thiophene imidazoline product;

[0048] Step 28: Place 1.85 g of cyanuric chloride and 18 mL of acetone into a four-necked flask, place it in a cooling water bath, maintain the temperature at 3-5°C and stir to make it dissolve evenly; dissolve 3.5 g of polyethylene glycol methyl ether 500 in 10 mL of acetone, slowly add it dropwise into the flask using a dropping funnel, and keep stirring at low temperature for 2 hours.

[0049] Step 29: Raise the temperature to 45°C, slowly add 6 g of thiophene imidazoline dissolved in 10 mL of acetone into the flask through a dropping funnel, and react for 3.5 hours under stirring; turn on the reflux condenser, raise the temperature to 100°C, adjust the pH to 7-8 with sodium carbonate, dissolve 3.5 g of polyethylene glycol methyl ether 500 in 15 mL of acetone, and slowly add it dropwise into the flask with a dropping funnel, and react for 5 hours.

[0050] Step 210: The liquid product is transferred to a distillation flask, acetone is removed by vacuum distillation, and the obtained crude product is dissolved in dichloromethane, and allowed to stand to separate into layers, and the upper clear liquid is taken and vacuum distilled again to obtain a white viscous liquid triazine polyether bithiphene imidazoline.

[0051] Embodiment 2:

[0052] 1. Preparation method of high temperature corrosion inhibitor:

[0053] Step 1: Add 4.5 g of sodium thiosulfate into a 100 mL beaker, add 20 mL of tap water, and stir at 400 r / min for 15 min until evenly dissolved.

[0054] Step 2: Add 17 g of phenylalanine imidazoline erucamide into a 250 mL beaker, and add 12 g of triazine polyether bithiphene imidazoline, 1.5 g of decapolyglycerol stearate, and 45 mL of tap water, respectively, and stir at 500 r / min for 15 min.

[0055] Step 3: Slowly add the solution in step 1 to the solution in step 2, and continue stirring at 400 r / min for 20 min to obtain the final product.

[0056] 2. Preparation method of phenylalanine imidazoline erucic acid amide:

[0057] Step 21: Weigh 16 g of phenylalanine, 25 mL of tetraethylenepentamine, and 17 mL of water-carrying agent xylene, add them into a three-necked flask, install a reflux condenser, heat to 120° C. under stirring, react for 4.5 hours, and separate the large amount of water generated from the reaction system;

[0058] Step 22: Continue heating to 215°C and react for 3 hours to obtain a crude product;

[0059] Step 23: The crude product is transferred to a distillation flask, and is subjected to rotary evaporation using a rotary evaporator to remove excess water and solvent xylene to obtain a crude phenylalanine imidazoline product;

[0060] Step 24: Dissolve 27.5 mL of erucic acid in 28 mL of ethanol, transfer all the crude product in step 3 into a four-necked flask, add 20 mL of water-carrying agent xylene, heat to 125°C with stirring, turn on the reflux condenser, slowly drop erucic acid into the four-necked flask from the dropping funnel, and react for 2.5 hours to obtain a white viscous liquid;

[0061] Step 25: The liquid product is transferred to a distillation flask, and is subjected to rotary evaporation using a rotary evaporator to remove excess water and solvent xylene to obtain phenylalanine imidazoline erucamide.

[0062] 3. Preparation method of triazine-based polyether bithiphene imidazoline

[0063] Step 26: Weigh 8.5 g of 2-thiophenecarboxylic acid, 15 mL of tetraethylenepentamine, and 15 mL of water-carrying agent xylene, add them into a three-necked flask, install a reflux condenser, heat to 120° C. under stirring, react for 4.5 hours, and separate the large amount of water generated from the reaction system;

[0064] Step 27: Continue to raise the temperature to 220° C. and react for 3 hours to obtain a crude product; transfer the crude product to a distillation flask, and use a rotary evaporator to remove excess water and solvent xylene to obtain a crude thiophene imidazoline product;

[0065] Step 28: Place 1.85 g of cyanuric chloride and 18 mL of acetone into a four-necked flask, place it in a cooling water bath, maintain the temperature at 3-5°C and stir to make it dissolve evenly; dissolve 3.5 g of polyethylene glycol methyl ether 500 in 10 mL of acetone, slowly add it dropwise into the flask using a dropping funnel, and keep stirring at low temperature for 2 hours.

[0066] Step 29: Raise the temperature to 45°C, slowly add 6 g of thiophene imidazoline dissolved in 10 mL of acetone into the flask through a dropping funnel, and react for 3.5 hours under stirring; turn on the reflux condenser, raise the temperature to 100°C, adjust the pH to 7-8 with sodium carbonate, dissolve 3.5 g of polyethylene glycol methyl ether 500 in 15 mL of acetone, and slowly add it dropwise into the flask with a dropping funnel, and react for 5 hours.

[0067] Step 210: The liquid product is transferred to a distillation flask, acetone is removed by vacuum distillation, and the obtained crude product is dissolved in dichloromethane, and allowed to stand to separate into layers, and the upper clear liquid is taken and vacuum distilled again to obtain a white viscous liquid triazine polyether bithiphene imidazoline.

[0068] Embodiment 3:

[0069] 1. Preparation method of high temperature corrosion inhibitor

[0070] Step 1: Add 3.5g sodium bisulfite into a 100mL beaker, add 20mL tap water, and stir at 400r / min for 15min until evenly dissolved.

[0071] Step 2: Add 15.3 g of phenylalanine imidazoline erucamide into a 250 mL beaker, and add 12 g of triazine polyether bithiphene imidazoline, 2.2 g of decaglycerol oleate, and 47 mL of tap water, respectively, and stir at 500 r / min for 15 min.

[0072] Step 3: Slowly add the solution in step 1 to the solution in step 2, and continue stirring at 400 r / min for 20 min to obtain the final product.

[0073] 2. Preparation method of phenylalanine imidazoline erucic acid amide:

[0074] Step 21: Weigh 17.1 g of phenylalanine, 25 mL of tetraethylenepentamine, and 17 mL of water-carrying agent xylene, add them into a three-necked flask, install a reflux condenser, heat to 120° C. under stirring, react for 4.5 hours, and separate the large amount of water generated from the reaction system;

[0075] Step 22: Continue heating to 215°C and react for 3 hours to obtain a crude product;

[0076] Step 23: The crude product is transferred to a distillation flask, and is evaporated using a rotary evaporator to remove excess water and solvent xylene to obtain a crude phenylalanine imidazoline product.

[0077] Step 24: Dissolve 28 mL of erucic acid in 28 mL of ethanol, transfer all the crude product in step 3 into a four-necked flask, add 20 mL of water-carrying agent xylene, raise the temperature to 125°C with stirring, turn on the reflux condenser, slowly add erucic acid from the dropping funnel into the four-necked flask, and react for 2.5 hours to obtain a white viscous liquid.

[0078] Step 25: The liquid product was transferred to a distillation flask and evaporated using a rotary evaporator to remove excess water and solvent xylene to obtain the attached Figure 1 Phenylalanine imidazoline erucamide shown.

[0079] 3. Preparation method of triazine-based polyether bithiphene imidazoline:

[0080] Step 26: Weigh 10.2 g of 2-thiophenecarboxylic acid, 19 mL of tetraethylenepentamine, and 18 mL of water-carrying agent xylene, add them into a three-necked flask, install a reflux condenser, heat to 120° C. under stirring, react for 5 hours, and separate the large amount of water generated from the reaction system;

[0081] Step 27: Continue to raise the temperature to 225° C. and react for 3.5 hours to obtain a crude product; transfer the crude product to a distillation flask, and use a rotary evaporator to remove excess water and solvent xylene to obtain a crude thiophene imidazoline product.

[0082] Step 28: Place 2.05 g of cyanuric chloride and 20 mL of acetone into a four-necked flask, place it in a cooling water bath, maintain the temperature at 1-3°C and stir to make it dissolve evenly; dissolve 3.9 g of polyethylene glycol methyl ether 500 in 10 mL of acetone, slowly add it dropwise into the flask using a dropping funnel, and stir and react at low temperature for 2.5 hours.

[0083] Step 29: Raise the temperature to 50°C, slowly add 7.5 g of thiophene imidazoline dissolved in 10 mL of acetone into the flask through a dropping funnel, and react for 3.5 hours under stirring; turn on the reflux condenser, raise the temperature to 100°C, adjust the pH to 7-8 with sodium carbonate, dissolve 3.9 g of polyethylene glycol methyl ether 500 in 15 mL of acetone, and slowly add it dropwise into the flask using a dropping funnel, and react for 5.5 hours.

[0084] Step 210: The liquid product is transferred to a distillation flask, acetone is removed by vacuum distillation, and the obtained crude product is dissolved in dichloromethane, allowed to stand to separate, and the supernatant is taken and vacuum distilled again to obtain the attached Figure 2 The white viscous liquid triazine polyether bithiophene imidazoline is shown. Figure 2 Where N=12.

[0085] Embodiment 4:

[0086] 1. Preparation method of high temperature corrosion inhibitor

[0087] Step 1: Add 3g of sodium bisulfite into a 100mL beaker, add 20mL of tap water, and stir at 400r / min for 15min until evenly dissolved.

[0088] Step 2: Add 20 g of phenylalanine imidazoline erucamide into a 250 mL beaker, and add 15 g of triazine polyether bithiphene imidazoline, 1 g of decaglycerol stearate, and 46 mL of tap water, respectively, and stir at 500 r / min for 15 min.

[0089] Step 3: Slowly add the solution in step 1 to the solution in step 2, and continue stirring at 400 r / min for 20 min to obtain the final product.

[0090] 2. Preparation method of phenylalanine imidazoline erucic acid amide

[0091] Step 21: Weigh 18.3 g of phenylalanine, 25 mL of tetraethylenepentamine, and 17 mL of water-carrying agent xylene, add them into a three-necked flask, install a reflux condenser, heat to 130° C. under stirring, react for 5 hours, and separate the large amount of water generated from the reaction system;

[0092] Step 22: Continue heating to 220°C and react for 3.5 hours to obtain a crude product;

[0093] Step 23: The crude product is transferred to a distillation flask, and is evaporated using a rotary evaporator to remove excess water and solvent xylene to obtain a crude phenylalanine imidazoline product.

[0094] Step 24: Dissolve 28 mL of erucic acid in 30 mL of ethanol, transfer all the crude product in step 3 into a four-necked flask, add 20 mL of water-carrying agent xylene, raise the temperature to 130°C with stirring, turn on the reflux condenser, slowly add erucic acid from the dropping funnel into the four-necked flask, and react for 3 hours to obtain a white viscous liquid.

[0095] Step 25: The liquid product is transferred to a distillation flask, and is subjected to rotary evaporation using a rotary evaporator to remove excess water and solvent xylene to obtain phenylalanine imidazoline erucamide.

[0096] 3. Preparation method of triazine-based polyether bithiphene imidazoline

[0097] Step 26: Weigh 11.5 g of 2-thiophenecarboxylic acid, 20 mL of tetraethylenepentamine, and 20 mL of water-carrying agent xylene, add them into a three-necked flask, install a reflux condenser, heat to 125° C. under stirring, react for 5 hours, and separate the large amount of water generated from the reaction system;

[0098] Step 27: Continue to raise the temperature to 230° C. and react for 4 hours to obtain a crude product; transfer the crude product to a distillation flask, and use a rotary evaporator to remove excess water and solvent xylene to obtain a crude thiophene imidazoline product.

[0099] Step 28: Place 2.4 g of cyanuric chloride and 25 mL of acetone into a four-necked flask, place it in a cooling water bath, maintain the temperature at 0-2°C and stir to make it dissolve evenly; dissolve 4.5 g of polyethylene glycol methyl ether 500 in 15 mL of acetone, slowly add it dropwise into the flask using a dropping funnel, and stir and react at low temperature for 2.5 hours.

[0100] Step 29: Raise the temperature to 50°C, slowly add 6.5 g of thiophene imidazoline dissolved in 10 mL of acetone into the flask through a dropping funnel, and react for 4 hours under stirring; turn on the reflux condenser, raise the temperature to 105°C, adjust the pH to 7-8 with sodium carbonate, dissolve 4.5 g of polyethylene glycol methyl ether 500 in 20 mL of acetone, and slowly add it dropwise into the flask with a dropping funnel, and react for 5.5 hours.

[0101] Step 20: The liquid product is transferred to a distillation flask, acetone is removed by vacuum distillation, and the obtained crude product is dissolved in dichloromethane, and allowed to stand to separate into layers, and the supernatant is taken and vacuum distilled again to obtain a white viscous liquid triazine polyether bithiophene imidazoline.

[0102] Embodiment 5:

[0103] 1. Preparation method of high temperature corrosion inhibitor:

[0104] Step 1: Add 4g of sodium bisulfite into a 100mL beaker, add 20mL of tap water, and stir at 400r / min for 15min until evenly dissolved.

[0105] Step 2: Add 15 g of phenylalanine imidazoline erucamide into a 250 mL beaker, and add 10 g of triazine polyether bithiphene imidazoline, 3 g of decaglycerol oleate, and 48 mL of tap water, respectively, and stir at 500 r / min for 15 min.

[0106] Step 3: Slowly add the solution in step 1 to the solution in step 2, and continue stirring at 400 r / min for 20 min to obtain the final product.

[0107] 2. Preparation method of phenylalanine imidazoline erucic acid amide

[0108] Step 21: Weigh 19.3 g of phenylalanine, 30 mL of tetraethylenepentamine, and 20 mL of water-carrying agent xylene, add them into a three-necked flask, install a reflux condenser, heat to 130° C. under stirring, react for 5 hours, and separate the large amount of water generated from the reaction system;

[0109] Step 22: Continue to raise the temperature to 225°C and react for 4 hours to obtain a crude product;

[0110] Step 23: The crude product is transferred to a distillation flask, and is evaporated using a rotary evaporator to remove excess water and solvent xylene to obtain a crude phenylalanine imidazoline product.

[0111] Step 24: Dissolve 30 mL of erucic acid in 30 mL of ethanol, transfer all the crude product in step 3 into a four-necked flask, add 25 mL of water-carrying agent xylene, raise the temperature to 130°C with stirring, turn on the reflux condenser, slowly add erucic acid from the dropping funnel into the four-necked flask, and react for 2.5 hours to obtain a white viscous liquid.

[0112] Step 25: The liquid product is transferred to a distillation flask, and is subjected to rotary evaporation using a rotary evaporator to remove excess water and solvent xylene to obtain phenylalanine imidazoline erucamide.

[0113] 3. Preparation method of triazine-based polyether bithiphene imidazoline

[0114] Step 26: Weigh 8.5 g of 2-thiophenecarboxylic acid, 15 mL of tetraethylenepentamine, and 15 mL of water-carrying agent xylene, add them into a three-necked flask, install a reflux condenser, heat to 120° C. under stirring, react for 4.5 hours, and separate the large amount of water generated from the reaction system;

[0115] Step 27: Continue to raise the temperature to 220° C. and react for 3 hours to obtain a crude product; transfer the crude product to a distillation flask, and use a rotary evaporator to remove excess water and solvent xylene to obtain a crude thiophene imidazoline product.

[0116] Step 28: Place 1.85 g of cyanuric chloride and 18 mL of acetone into a four-necked flask, place it in a cooling water bath, maintain the temperature at 3-5°C and stir to make it dissolve evenly; dissolve 3.5 g of polyethylene glycol methyl ether 500 in 10 mL of acetone, slowly add it dropwise into the flask using a dropping funnel, and keep stirring at low temperature for 2 hours.

[0117] Step 29: Raise the temperature to 45°C, slowly add 6 g of thiophene imidazoline dissolved in 10 mL of acetone into the flask through a dropping funnel, and react for 3.5 hours under stirring; turn on the reflux condenser, raise the temperature to 100°C, adjust the pH to 7-8 with sodium carbonate, dissolve 3.5 g of polyethylene glycol methyl ether 500 in 15 mL of acetone, and slowly add it dropwise into the flask with a dropping funnel, and react for 5 hours.

[0118] Step 210: The liquid product is transferred to a distillation flask, acetone is removed by vacuum distillation, and the obtained crude product is dissolved in dichloromethane, and allowed to stand to separate into layers, and the upper clear liquid is taken and vacuum distilled again to obtain a white viscous liquid triazine polyether bithiphene imidazoline.

[0119] Comparative Example 1:

[0120] The CO2 corrosion inhibitor was prepared according to the preparation method of Example 1 in the patent CN107699900 B of "A CO2 corrosion inhibitor for oil and gas field gathering and transportation pipeline and preparation method thereof".

[0121] Comparative Example 2:

[0122] A water-soluble liquid corrosion inhibitor for CO2 corrosion resistance is used in a block of Dagang Oilfield.

[0123] Test Example 1:

[0124] In order to verify the molecular structure of the high temperature corrosion inhibitor of the present invention, the present invention conducted infrared spectroscopy detection on the high temperature corrosion inhibitor in the study. The infrared spectroscopy and nuclear magnetic resonance detection results are as follows: Figure 3 As shown;

[0125] from Figure 3 It can be seen that at 717.35cm-1 , 1114.08cm -1 , 1630.12cm -1 , 1660.94cm -1 , 2905.46cm -1 , 2954.71cm -1 , 3479.03cm-1 and other strong absorption peaks appear near. -1 Nearby is the stretching vibration peak of the thiophene group, 1114.08 cm -1 Nearby is the stretching vibration peak of the polyether group, 1630.12 cm -1 Nearby is the stretching vibration peak of the triazine group, 1660.94 cm -1 Nearby is the stretching vibration peak of the imidazoline group, 2905.46cm -1 Nearby is the bending vibration absorption of phenylalanine, 2954.71cm -1 Nearby is the bending vibration absorption peak of the erucic acid amide group, 3479.03cm -1 Nearby is the stretching vibration peak of amino group -NH2.

[0126] The above results show that the molecular structure of the high temperature corrosion inhibitor contains thiophene, polyether, triazine, imidazoline, phenylalanine, erucic acid amide, amino group structures, etc., which is consistent with the above molecular structure.

[0127] Test Example 2:

[0128] In this test, for water quality with two different corrosion conditions in a block of Dagang Oilfield, the corrosion inhibition effects of the corrosion inhibitors prepared in Examples 1-5 and Comparative Examples 1 and 2 were compared and evaluated, and the evaluation standard was implemented in accordance with Q / BGBH 0024-2023.

[0129] Test conditions: corrosion inhibitor dosage 150 mg / L, temperature 120°C, CO2 partial pressure 8 MPa, rotation speed 150 r / min, test time 5 days.

[0130] Water quality conditions are as follows Figure 4 As shown in the figure, H2S concentration is measured by the sulfide content in water. The detection standard is based on HJ / T 60-2000. The other indicators are based on SY / T 5523-2016. The evaluation results are shown in the attached figure. Figure 5 As shown;

[0131] By the attached Figure 4 , 5 It can be seen that the water-soluble corrosion inhibitor provided in Examples 1-5 has an obvious dynamic corrosion inhibition effect on two types of multi-factor highly corrosive water in a block of Dagang Oilfield under high temperature and high pressure conditions. It is a high-temperature corrosion inhibitor that is resistant to multi-factor corrosion and can be promoted on a large scale.

[0132] Utilizing the technical solution described in the present invention, or those skilled in the art designing a similar technical solution inspired by the technical solution of the present invention to achieve the above-mentioned technical effects, all fall within the protection scope of the present invention.

Claims

1. A method for preparing a high temperature corrosion inhibitor for inhibiting multiple corrosion factors, characterized in that: The preparation method comprises the following steps: Step 1: Add 3-5g of deoxidizer into a 100mL beaker, add 20mL of tap water, stir at 400r / min for 10-20min until dissolved evenly, and set aside for later use; Step 2: Add 15-25g of phenylalanine imidazoline erucic acid amide into a 250mL beaker, add 10-15g of triazine polyether bithiophene imidazoline, 1-3g of polyglycerol fatty acid ester and 40-70mL of tap water respectively, stir at 500r / min for 15-20min, and set aside for use; Step 3: Slowly add the solution in step 1 to the solution in step 2, and continue stirring at 400 r / min for 20-30 min to obtain the final product.

2. The method for preparing a high temperature corrosion inhibitor for inhibiting multiple corrosion factors according to claim 1, characterized in that: The deoxidizer in step 1 is one of sodium thiosulfate or sodium bisulfite.

3. The method for preparing a high temperature corrosion inhibitor for inhibiting multiple corrosion factors according to claim 1, characterized in that: The polyglycerol fatty acid ester in step 2 is one of decaglycerol oleate or decaglycerol stearate.

4. The method for preparing a high temperature corrosion inhibitor for inhibiting multiple corrosion factors according to claim 1, characterized in that: The preparation method of phenylalanine imidazoline erucic acid amide in step 2 is: Step 21: Weigh 15-20 g of phenylalanine, 25-35 mL of tetraethylenepentamine, and 15-25 mL of water-carrying agent xylene in sequence, add them into a three-necked flask, install a reflux condenser, heat to 110-130° C. while stirring, react for 4-5 hours, and separate the large amount of water generated from the reaction system; Step 22: Continue to raise the temperature to 210-230°C and react for 3-4 hours to obtain a crude product; Step 23: The crude product is transferred to a distillation flask, and is subjected to rotary evaporation using a rotary evaporator to remove excess water and solvent xylene to obtain a crude phenylalanine imidazoline product; Step 24: Dissolve 25-35 mL of erucic acid in 25-35 mL of ethanol, transfer all the crude phenylalanine imidazoline product in step 23 into a four-necked flask, add 15-25 mL of water-carrying agent xylene, heat to 120-140° C. under stirring, turn on the reflux condenser, slowly drop erucic acid into the four-necked flask from the dropping funnel, and react for 1.5-3 hours to obtain a white viscous liquid; Step 25: The liquid product is transferred to a distillation flask, and is subjected to rotary evaporation using a rotary evaporator to remove excess water and solvent xylene to obtain phenylalanine imidazoline erucamide.

5. The method for preparing a high temperature corrosion inhibitor for inhibiting multiple corrosion factors according to claim 1, characterized in that: The preparation method of triazine-based polyether bithiphene imidazoline in step 2: Step 26: Weigh 8-12 g of 2-thiophenecarboxylic acid, 15-25 mL of tetraethylenepentamine, and 15-25 mL of water-carrying agent xylene, add them into a three-necked flask, install a reflux condenser, heat to 110-130° C. under stirring, react for 4-5 hours, and separate the large amount of water generated from the reaction system; Step 27: Continue to raise the temperature to 210-230° C., react for 3-4 hours to obtain a crude product, transfer the crude product to a distillation flask, and use a rotary evaporator to remove excess water and solvent xylene to obtain a crude thiophene imidazoline product; Step 28: Place 1.5-3.0 g of cyanuric chloride and 20-30 mL of acetone into a four-necked flask, place in a cooling water bath, maintain the temperature at 0-5°C and stir to make it dissolve evenly, dissolve 3-5 g of polyethylene glycol methyl ether 500 in 15-20 mL of acetone, slowly add dropwise into the flask using a dropping funnel, and stir and react at low temperature for 2-3 hours; Step 29: Raise the temperature to 40-50°C, slowly add 5-7 g of thiophene imidazoline dissolved in 10 mL of acetone into the flask through a dropping funnel, and react for 3-4 hours under stirring; turn on the reflux condenser, raise the temperature to 90-105°C, adjust the pH to 7-8 with sodium carbonate, dissolve 3-5 g of polyethylene glycol methyl ether 500 in 15-20 mL of acetone, and slowly add dropwise into the flask with a dropping funnel, and react for 5-6 hours; Step 210: The liquid product is transferred to a distillation flask, acetone is removed by vacuum distillation, and the obtained crude product is dissolved in dichloromethane, and allowed to stand to separate into layers, and the upper clear liquid is taken and vacuum distilled again to obtain a white viscous liquid triazine polyether bithiphene imidazoline.

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