Acid-gas-resistant corrosion inhibitor as well as preparation method and application thereof

Abstract

The invention relates to the technical field of corrosion inhibitors and preparation thereof, in particular to an acid-gas-resistant corrosion inhibitor and a preparation method and application thereof, and the acid-gas-resistant corrosion inhibitor is obtained according to the following method: uniformly mixing a required amount of first polymer and a required amount of second polymer, and compounding to obtain the acid-gas-resistant corrosion inhibitor, the first polymer is a linear imidazoline polymer prepared by reacting imidazoline with dicarboxylic acid and halogenated alkane, and the second polymer is a cationic linear structure imidazoline polymer prepared by reacting imidazoline with a chlorine-containing compound, guanidine hydrochloride and primary amine. According to the corrosion inhibitor, n imidazoline rings in molecules of the first polymer are adsorbed on a stainless steel pipe, the adsorption capacity and the scouring resistance of the corrosion inhibitor are improved, the adsorbability of imidazoline is improved through the second polymer, meanwhile, a primary amine hydrophobic group is introduced, the hydrophobic capacity of imidazoline is improved, a guanidine structure is introduced into an imidazoline structure, and the corrosion inhibitor has the advantages that the corrosion inhibitor is more environmentally friendly; therefore, the product has a strong bactericidal effect and can be widely applied to corrosion protection, sterilization and scale inhibition of oil and gas wells.

Description

Technical Field

[0001] The invention relates to the technical field of corrosion inhibitors and preparation thereof, and is an acid gas resistant corrosion inhibitor and a preparation method and application thereof. Background Art

[0002] CO2-H2S corrosion has always been a thorny problem and research hotspot in the oil industry. The equipment and pipeline corrosion failure caused by CO2-H2S corrosion has caused huge economic losses and serious social consequences, so the research on inhibiting CO2-H2S corrosion has far-reaching economic and social effects. Especially in the process of oil field development and pipeline network gathering and transportation, corrosion, scaling, and bacterial growth are common problems at present. If they are not effectively controlled, they will have a serious impact on oil field production.

[0003] Imidazoline corrosion inhibitors have excellent corrosion inhibition performance. As the mass concentration of the corrosion inhibitor increases, the corrosion inhibition rate increases. When the mass concentration of N-alkylbenzimidazolinium cationic corrosion inhibitor is 50mg / L, the corrosion inhibition rate reaches 97.15%. In recent years, there have been many studies on the use of imidazoline corrosion inhibitors to treat CO2-H2S corrosion problems. The purpose of corrosion inhibition is achieved by forming a monomolecular adsorption film on the surface of the metal through contact with the acidic medium, thereby reducing its potential.

[0004] The Chinese patent document with publication number CN116497359A discloses an acid gas corrosion inhibitor, which includes 10-15 parts of phosphine carboxylic acid, 20-30 parts of mercaptobenzothiazole, 10-20 parts of benzotriazole, 15-30 parts of sulfonated lignin, 10-15 parts of ammonium benzoate, and 1-10 parts of distilled water, which are sequentially added into a stirred kettle for preheating, stirring, heating, and cooling. However, the above prior art is to add the corrosion inhibitor, scale inhibitor, and bactericide after simple compounding, which not only leads to a relatively high cost of the agent, but also the compatibility between the products is also a major technical difficulty to be solved.

[0005] Therefore, it is necessary to develop an anti-acid gas corrosion inhibitor with excellent corrosion protection, sterilization and scale inhibition effects for use in oil field development. Summary of the invention

[0006] The present invention provides an acid gas resistant corrosion inhibitor and a preparation method and application thereof, which overcome the deficiencies of the above-mentioned prior art and can effectively solve the problems of high cost and incompatibility of the existing imidazoline corrosion inhibitors, which lead to poor product performance.

[0007] One of the technical solutions of the present invention is achieved through the following measures: a method for preparing an anti-acidic gas corrosion inhibitor is carried out according to the following method: the required amounts of a first polymer and a second polymer are uniformly mixed and compounded, wherein the first polymer is a linear imidazoline polymer prepared by reacting imidazoline with a dicarboxylic acid and a halogenated alkane, and the second polymer is a cationic linear structure imidazoline polymer prepared by reacting imidazoline with a chlorine-containing compound, guanidine hydrochloride and a primary amine.

[0008] The following is a further optimization and / or improvement of one of the above-mentioned technical solutions: The first polymer is obtained according to the following method: S1, mixing a required amount of dicarboxylic acid and polyamine and reacting them to obtain an intermediate 1; S2, mixing the intermediate 1 with a required amount of dicarboxylic acid and reacting them to obtain the intermediate 2; S3, mixing the intermediate 2 with a required amount of halogenated alkane and reacting them to obtain a first polymer.

[0009] In the above step S1, the molar ratio of dicarboxylic acid to polyamine is 0.9 to 1.1:0.9 to 1.1, the reaction temperature is 250° C. to 300° C., and the reaction time is 9 h to 11 h, wherein the polyamine is polyethylene polyamine.

[0010] In the above step S2, the molar ratio of the intermediate 1 to the dicarboxylic acid is 0.9 to 1.1:0.9 to 1.1, the reaction temperature is 145° C. to 155° C., and the reaction time is 2.5 h to 3.5 h.

[0011] In the above step S3, the halogenated alkane is one of dodecane bromide, hexadecane bromide, dodecane chloride and hexadecane chloride.

[0012] The second polymer is obtained according to the following method: S11, reacting a required amount of the intermediate 1 obtained in step S1 with a chlorine-containing compound to obtain an intermediate 3; S12, mixing the intermediate three with a required amount of guanidine hydrochloride and a primary amine and reacting them to obtain a second polymer.

[0013] In the above step S11, the molar ratio of the intermediate 1 to the chlorine-containing compound is 0.9 to 1.1:0.9 to 1.1, the reaction temperature is 70° C. to 100° C., the reaction time is 2.5 h to 3.5 h, and the chlorine-containing compound is 1,4-dichlorobenzyl.

[0014] In the above step S12, the molar ratio of intermediate three to guanidine hydrochloride and primary amine is 0.9 to 1.1:1.5 to 2:1.5 to 2, the reaction temperature is 145°C to 155°C, the reaction time is 3.5h to 4.5h, and the primary amine is one of dodecyl primary amine, tetradecyl primary amine, hexadecyl primary amine and octadecyl primary amine.

[0015] The second technical solution of the present invention is achieved through the following measures: an anti-acidic gas corrosion inhibitor is obtained by a preparation method of the anti-acidic gas corrosion inhibitor.

[0016] The third technical solution of the present invention is achieved through the following measures: application of an anti-acid gas corrosion inhibitor in corrosion protection, sterilization and scale inhibition of oil and gas wells.

[0017] In the present invention, n imidazoline rings are adsorbed on the stainless steel pipe in the molecule of the first polymer, which improves the adsorption capacity and erosion resistance of the corrosion inhibitor. The second polymer increases the adsorption of imidazoline and introduces primary amine hydrophobic groups to improve the hydrophobicity of imidazoline. A guanidine structure is also introduced into the imidazoline structure, so that the product has a strong bactericidal effect and can be widely used in corrosion protection, sterilization and scale inhibition of oil and gas wells. DETAILED DESCRIPTION

[0018] The present invention is not limited by the following embodiments, and specific implementation methods can be determined according to the technical scheme of the present invention and actual conditions. Unless otherwise specified, the various chemical reagents and chemicals mentioned in the present invention are all known and commonly used chemical reagents and chemicals in the prior art.

[0019] The present invention will be further described below in conjunction with embodiments: Example 1: The preparation method of the anti-acidic gas corrosion inhibitor is carried out according to the following method: the required amounts of a first polymer and a second polymer are uniformly mixed and compounded, wherein the first polymer is a linear imidazoline polymer prepared by reacting imidazoline with a dicarboxylic acid and a halogenated alkane, and the second polymer is a cationic linear structure imidazoline polymer prepared by reacting imidazoline with a chlorine-containing compound, guanidine hydrochloride and a primary amine.

[0020] Example 2: As an optimization of the above example, the first polymer is obtained according to the following method: S1, mixing a required amount of dicarboxylic acid and polyamine and reacting them to obtain an intermediate 1; S2, mixing the intermediate 1 with a required amount of dicarboxylic acid and reacting them to obtain the intermediate 2; S3, mixing the intermediate 2 with a required amount of halogenated alkane and reacting them to obtain a first polymer.

[0021] The chemical reaction mechanism for obtaining intermediate 1 in the present invention is as follows: The chemical reaction mechanism to obtain intermediate 2 is as follows: The chemical reaction mechanism for obtaining the first polymer is as follows: Example 3: As an optimization of the above example, in step S1, the molar ratio of dicarboxylic acid to polyamine is 0.9 to 1.1:0.9 to 1.1, the reaction temperature is 250°C to 300°C, the reaction time is 9h to 11h, and the polyamine is polyethylene polyamine.

[0022] Example 4: As an optimization of the above example, in step S2, the molar ratio of intermediate 1 to dicarboxylic acid is 0.9 to 1.1:0.9 to 1.1, the reaction temperature is 145°C to 155°C, and the reaction time is 2.5h to 3.5h.

[0023] Embodiment 5: As an optimization of the above embodiment, in step S3, the halogenated alkane is one of brominated dodecane, brominated hexadecane, chlorododecane and chlorohexadecane.

[0024] Example 6: As an optimization of the above example, the second polymer is obtained according to the following method: S11, reacting a required amount of the intermediate 1 obtained in step S1 with a chlorine-containing compound to obtain an intermediate 3; S12, mixing the intermediate three with a required amount of guanidine hydrochloride and a primary amine and reacting them to obtain a second polymer.

[0025] The chemical reaction mechanism for obtaining intermediate three in the present invention is as follows: The chemical reaction mechanism to obtain the second polymer is as follows: Example 7: As an optimization of the above example, in step S11, the molar ratio of intermediate 1 to the chlorine-containing compound is 0.9 to 1.1:0.9 to 1.1, the reaction temperature is 70°C to 100°C, the reaction time is 2.5h to 3.5h, and the chlorine-containing compound is 1,4-dichlorobenzyl.

[0026] Example 8: As an optimization of the above example, in step S12, the molar ratio of intermediate three to guanidine hydrochloride and primary amine is 0.9 to 1.1:1.5 to 2:1.5 to 2, the reaction temperature is 145°C to 155°C, the reaction time is 3.5h to 4.5h, and the primary amine is one of dodecyl primary amine, tetradecyl primary amine, hexadecyl primary amine and octadecyl primary amine.

[0027] Example 9: The anti-acidic gas corrosion inhibitor obtained by the preparation method of the anti-acidic gas corrosion inhibitor.

[0028] Example 10: Application of the anti-acid gas corrosion inhibitor in oil and gas well corrosion protection, sterilization and scale inhibition.

[0029] Example 11: The preparation method of the anti-acid gas corrosion inhibitor is carried out according to the following method: In the first step, 146 kg (1 kmol) of adipic acid and 878 kg (1 kmol) of polyethylene polyamine (molecular weight 439) were added to the reactor, mixed evenly, and then the temperature was slowly raised to 280°C, and refluxed for 10 hours to obtain intermediate 1; In the second step, the intermediate 1 is mixed evenly with 146 kg (1 kmol) of adipic acid, and the temperature is controlled at 150° C. for 3 h to obtain the intermediate 2. Step 3: Add 249 kg (1 kmol) of bromododecane to the intermediate 2, and react at 80°C for 4 hours to obtain the first polymer. Step 4: Take 1024 kg of intermediate 1, add 175 kg (1 kmol) of 1,4-dichlorobenzyl, and react at 80°C for 3 hours to prepare intermediate 3; Step 5: Add 191 kg guanidine hydrochloride (2 kmol) and 429 kg hexadecyl primary amine (2 kmol) to the intermediate 3, and react at 150°C for 4 hours to prepare a second polymer; In the sixth step, the first polymer and the second polymer are mixed in a mass ratio of 1:1, and stirred evenly to obtain an anti-acid gas corrosion inhibitor.

[0030] Example 12: The difference between the preparation method of the anti-acid gas corrosion inhibitor and Example 11 is that: In the fifth step, 429 kg of hexadecyl primary amine was replaced with 370.6 kg of dodecyl primary amine; The rest of the process is the same.

[0031] Example 13: The difference between the preparation method of the anti-acid gas corrosion inhibitor and that of Example 11 is that: In the second step, 146 kg of adipic acid was replaced with 174 kg of suberic acid; The rest of the process is the same.

[0032] Example 14: The difference between the preparation method of the acid gas corrosion inhibitor and that of Example 11 is that: In the third step, 249 kg of dodecane bromide is replaced with 205 kg of dodecane chloride; The rest of the process is the same.

[0033] Example 15: The difference between the preparation method of the anti-acid gas corrosion inhibitor and that of Example 11 is that: In the third step, 249 kg of dodecane bromide is replaced with 261 kg of hexadecane chloride; The rest of the process is the same.

[0034] The performance test and evaluation of the anti-acid gas corrosion inhibitor obtained according to Examples 11 to 15 are as follows: (1) Evaluation of bactericidal performance According to SY / T5890 "Bactericide Performance Evaluation Method", the bactericidal effect of the anti-acidic gas corrosion inhibitor on sulfate-reducing bacteria, iron bacteria and saprophytic bacteria was determined by using the extinction dilution method. The dosing concentration of the anti-acidic gas corrosion inhibitor of the present invention is 1%.

[0035] Comparative Example 1: Using a monoguanidine fungicide.

[0036] ((Bacteria test bottle SRB (sulfate reducing bacteria) readings, IB (iron bacteria) readings, TGB (saprophytic bacteria) readings) The experimental results are shown in Table 1.

[0037] Table 1 .

[0038] It can be seen from Table 1 that the bactericidal performance of the acid gas resistant corrosion inhibitor of the present invention is slightly better than that of the monoguanidine bactericide on the market.

[0039] (2) Corrosion inhibition experiment Referring to the SYT5273 standard for the performance evaluation method of corrosion inhibitors for oilfield produced water reinjection water, six 1L stoppered bottles were taken, and oilfield water source well water and 1% of an acidic gas corrosion inhibitor (Examples 11 to 15) were added to make the volume 1L, and the prepared N80 hanging plate (with an outer size of 40mm×13mm×2mm, a round hole was drilled in the middle of one end 5mm away from the edge, and the surface area was 12cm 2 ), CO2 and H2S were introduced to saturation to simulate the working conditions in acidic oil and gas wells. The samples were placed in a constant temperature oven at 90°C for 14 days, and the coupons were taken out. After cleaning the corrosion products on the surface of the coupons, they were dried with cold air and weighed. The corrosion rate of the steel coupons was calculated according to formula (1). The results are shown in Table 2.

[0040] Formula (1) Among them, γ cis the corrosion rate, in mm / a; ω0 is the initial mass of the coupon, in g; ω1 is the mass of the coupon at the end of the experiment, in g; S is the surface area of ​​the coupon, in cm 2 ; t is the reaction time, in h; ρ is g / cm 3 .

[0041] Blank Example: CO2 and H2S were introduced into the water source well of the oil field until saturation, and the anti-acid gas corrosion inhibitor of the present invention was not added. The remaining steps were consistent with the above steps. The results are shown in Table 2.

[0042] Comparative Example 1: using oleic acid imidazoline corrosion inhibitor.

[0043] Table 2 .

[0044] It can be seen from Table 2 that the anti-acid gas corrosion inhibitor of the present invention has excellent corrosion inhibition performance, and its corrosion inhibition performance is better than that of oleic acid imidazoline.

[0045] Corrosion and sterilization tests show that the anti-acidic gas corrosion inhibitor of the present invention has good corrosion inhibition effect under simulated working conditions, with a corrosion inhibition rate lower than 0.05 mm / a, which is much lower than the corresponding industry standard. The sterilization rate meets the industry standard, and has good protective function for the inner wall of the casing in the annular space and the outer wall of the oil and gas pipeline in the acidic environment, thereby extending the service life and ensuring safe production in the oil field.

[0046] In summary, in the molecule of the first polymer of the present invention, n imidazoline rings are adsorbed on the stainless steel pipe, which improves the adsorption capacity and erosion resistance of the corrosion inhibitor. The second polymer increases the adsorption of imidazoline and introduces primary amine hydrophobic groups to improve the hydrophobicity of imidazoline. A guanidine structure is also introduced into the imidazoline structure, so that the product has a strong bactericidal effect and can be widely used in corrosion protection, sterilization, and scale inhibition of oil and gas wells.

[0047] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A method for preparing an acid gas corrosion inhibitor, characterized in that The method is as follows: the required amounts of a first polymer and a second polymer are uniformly mixed and then compounded, wherein the first polymer is a linear imidazoline polymer prepared by reacting imidazoline with a dicarboxylic acid and a halogenated alkane, and the second polymer is a cationic linear structure imidazoline polymer prepared by reacting imidazoline with a chlorine-containing compound, guanidine hydrochloride and a primary amine.

2. The method for preparing the anti-acid gas corrosion inhibitor according to claim 1, characterized in that The first polymer is obtained according to the following method: S1, mixing a required amount of dicarboxylic acid and polyamine and reacting them to obtain an intermediate 1; S2, mixing the intermediate 1 with a required amount of dicarboxylic acid and reacting them to obtain the intermediate 2; S3, mixing the intermediate 2 with a required amount of halogenated alkane and reacting them to obtain a first polymer.

3. The method for preparing the anti-acid gas corrosion inhibitor according to claim 2, characterized in that In step S1, the molar ratio of dicarboxylic acid to polyamine is 0.9 to 1.1:0.9 to 1.1, the reaction temperature is 250° C. to 300° C., and the reaction time is 9 h to 11 h, wherein the polyamine is polyethylene polyamine.

4. The method for preparing the anti-acid gas corrosion inhibitor according to claim 2 or 3, characterized in that In step S2, the molar ratio of intermediate 1 to dicarboxylic acid is 0.9 to 1.1:0.9 to 1.1, the reaction temperature is 145° C. to 155° C., and the reaction time is 2.5 h to 3.5 h.

5. The method for preparing the anti-acidic gas corrosion inhibitor according to claim 4, characterized in that In step S3, the halogenated alkane is one of dodecane bromide, hexadecane bromide, dodecane chloride, and hexadecane chloride.

6. The method for preparing the anti-acid gas corrosion inhibitor according to claim 2, 3 or 5, characterized in that The second polymer is obtained as follows: S11, reacting a required amount of the intermediate 1 obtained in step S1 with a chlorine-containing compound to obtain an intermediate 3; S12, mixing the intermediate three with a required amount of guanidine hydrochloride and a primary amine and reacting them to obtain a second polymer.

7. The method for preparing the anti-acidic gas corrosion inhibitor according to claim 6, characterized in that In step S11, the molar ratio of the intermediate 1 to the chlorine-containing compound is 0.9 to 1.1:0.9 to 1.1, the reaction temperature is 70° C. to 100° C., the reaction time is 2.5 h to 3.5 h, and the chlorine-containing compound is 1,4-dichlorobenzyl.

8. The method for preparing the anti-acid gas corrosion inhibitor according to claim 6, characterized in that In step S12, the molar ratio of intermediate three to guanidine hydrochloride and primary amine is 0.9 to 1.1:1.5 to 2:1.5 to 2, the reaction temperature is 145°C to 155°C, the reaction time is 3.5h to 4.5h, and the primary amine is one of dodecyl primary amine, tetradecyl primary amine, hexadecyl primary amine and octadecyl primary amine.

9. An anti-acidic gas corrosion inhibitor obtained according to the preparation method according to any one of claims 1 to 8.

10. Use of the anti-acid gas corrosion inhibitor according to claim 9 in corrosion protection, sterilization and scale inhibition of oil and gas wells.

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