Scale and swelling inhibitor and preparation method thereof

Abstract

The invention relates to the technical field of oil and gas field development chemistry, and discloses a scale and swelling inhibitor and a preparation method thereof.The preparation method of the scale and swelling inhibitor comprises the steps that acrylamide, dimethyl diallyl ammonium chloride and modified 2-aminobenzene-1, 3, 5-tricarboxylic acid are sequentially added into deionized water, stirring is conducted at the speed of 200-300 r / min till even dispersion is achieved, and the scale and swelling inhibitor is obtained. The preparation method comprises the following steps: firstly, adding the modified sulfonated silica sol, continuously stirring for 40-50 minutes to obtain a pre-polymerized solution, then introducing nitrogen for 20-30 minutes, heating to 55-60 DEG C, dropwise adding azobis (isobutylamidine hydrochloride) at the speed of 1-2 mL / min, carrying out heat preservation reaction for 4-6 hours after dropwise adding, and cooling to room temperature after the reaction is finished to obtain the scale-inhibiting and anti-swelling agent. The scale and swelling inhibitor is efficient and environment-friendly, and has good scale inhibition, swelling prevention, temperature resistance and washing resistance.

Description

Technical Field

[0001] This invention relates to the field of chemical technology for oil and gas field development, specifically to a scale inhibitor and anti-swelling agent and its preparation method. Background Technology

[0002] In oil and gas field fracturing operations, two key problems often arise after fracturing fluid is injected into the formation: First, incompatibility between the fracturing fluid and formation water leads to the precipitation of inorganic salts such as calcium carbonate and barium sulfate, forming scale that blocks formation pores and wellbore equipment, reducing reservoir permeability. Second, the aqueous phase in the fracturing fluid causes the hydration and expansion of reservoir clay minerals (such as montmorillonite), blocking rock pores and reducing oil and gas flow capacity. Traditional solutions mainly employ two approaches: one is to add single-function scale inhibitors and swelling inhibitors separately. This approach suffers from complex dosing procedures, high operating costs, and the potential for antagonistic interactions between different agents, leading to a decrease in overall treatment effectiveness. The other approach uses physically compounded bifunctional agents, simply mixing scale inhibitors and swelling inhibitors. However, this approach suffers from poor stability, is prone to stratification, and its functions are merely additive without synergistic effects. Under complex formation conditions such as high temperature and high salinity, one function often fails while the other is significantly reduced. Therefore, avoiding this phenomenon is crucial to solving the problem. For example, Chinese invention patent CN113980665B discloses a phosphorus-free nanoscale inhibitor and its preparation method. The preparation process of this invention is simple, contains no phosphorus, has no environmental pollution, and has high scale inhibition efficiency, but its anti-swelling performance and temperature resistance need to be improved. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, the present invention aims to provide a scale inhibitor and anti-swelling agent and its preparation method. The scale inhibitor and anti-swelling agent of the present invention is highly efficient and environmentally friendly, and has good scale inhibition, anti-swelling, temperature resistance and water washing resistance.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a scale inhibitor and anti-swelling agent, comprising the following weight components: 12-15 parts by weight of acrylamide, 6-8 parts by weight of dimethyl diallyl ammonium chloride, 0.5-0.8 parts by weight of modified sulfonated silica sol, 1-3 parts by weight of modified 2-aminobenzene-1,3,5-tricarboxylic acid, 0.08-0.12 parts by weight of azobisisobutyramidine hydrochloride, and 70-80 parts by weight of deionized water.

[0005] Furthermore, the preparation method of the modified sulfonated silica sol is as follows: Step 1: Add (3-mercaptopropyl)trimethoxysilane to deionized water and sonicate for 20-30 min. Then, slowly add 30% hydrogen peroxide solution at a rate of 3-4 drops / min while stirring. After the addition is complete, adjust the pH of the solution to 6.0 with 1 mol / L hydrochloric acid. Stir continuously at room temperature for 24-28 h. After the reaction is complete, add anhydrous sodium sulfite to the system and stir for 30-35 min. Dialyze using an 8000-10000 Da dialysis bag for 5-7 days, using deionized water as the dialysis fluid and changing the water 3-4 times a day. Freeze-dry at -75 to -85℃ for 48-72 h to obtain sulfonated silica sol. Step 2: Add 45-50 mL of anhydrous ethanol and 15-20 mL of deionized water to the reactor, mix to prepare a solution, then add 0.8-0.9 g of sulfonated silica sol, sonicate for 35-45 min, then add 0.65-0.72 g of γ-methacryloyloxypropyltrimethoxysilane, and adjust the pH of the system to 4 with 1 mol / L hydrochloric acid. Stir and reflux at 55-65℃ for 6-8 h. After the reaction is complete, dialyze using an 8000-10000 Da dialysis bag, using anhydrous ethanol as the dialysate, changing the ethanol 3-4 times a day. Freeze-dry at -75 to -85℃ for 48-72 h to obtain the modified sulfonated silica sol.

[0006] Furthermore, in step one, the ratio of deionized water, (3-mercaptopropyl)trimethoxysilane, 30% hydrogen peroxide solution, and anhydrous sodium sulfite is 3-4g:1-1.1g:6-6.1g:6-6.1g.

[0007] Furthermore, the dialysis time in step two is 2-3 days.

[0008] Furthermore, the method for preparing the modified 2-aminobenzene-1,3,5-tricarboxylic acid is as follows: S1: Add ammonium thiocyanate to acetonitrile solvent, mix well, and slowly add 4-vinylbenzoyl chloride dropwise while stirring at room temperature. After the addition is complete, stir the reaction for 4-6 hours. After the reaction is complete, filter, remove the solvent by rotary evaporation, concentrate under reduced pressure, and purify to obtain intermediate 1. S2: Add intermediate 1,2-aminophenyl-1,3,5-carboxylic acid to N,N-dimethylformamide solvent, stir and mix, then add triethylamine, and react at 40-50℃ for 8-12 h. After the reaction is completed, cool the reaction solution to room temperature, and slowly pour in deionized water while stirring. Filter, wash, recrystallize, and dry to obtain modified 2-aminophenyl-1,3,5-tricarboxylic acid.

[0009] Furthermore, the ratio of acetonitrile, ammonium thiocyanate, and 4-vinylbenzoyl chloride in S1 is 20-30 mL: 1.1-1.2 g: 1.6-1.7 g.

[0010] Further, the ratio of N,N-dimethylformamide, intermediate 1,2-aminobenzene-1,3,5-carboxylic acid, triethylamine, and deionized water in S2 is 25-35mL:1.7-1.8g:2.5-2.6g:0.8-0.85g:150-160mL.

[0011] Further, the preparation method of the scale inhibitor and anti-swelling agent is as follows: Acrylamide, dimethyl diallyl ammonium chloride, and modified 2-aminobenzene-1,3,5-tricarboxylic acid are added sequentially to deionized water and stirred at a speed of 200-300 r / min until uniformly dispersed. Then, modified sulfonated silica sol is added and stirring is continued for 40-50 min to obtain a prepolymer solution. Nitrogen gas is then introduced for 20-30 min, and the temperature is raised to 55-60℃. Azobisisobutyramidine hydrochloride is added dropwise at a rate of 1-2 mL / min. After the addition is completed, the reaction is kept at the temperature for 4-6 h. After the reaction is completed, the solution is cooled to room temperature to obtain the scale inhibitor and anti-swelling agent.

[0012] Compared with the prior art, the present invention has the following beneficial technical effects: This invention uses a free radical copolymerization reaction to copolymerize acrylamide, dimethyl diallyl ammonium chloride, modified 2-aminobenzene-1,3,5-tricarboxylic acid, and modified sulfonated silica sol to obtain a scale inhibitor and anti-swelling agent.

[0013] The modified 2-aminophenyl-1,3,5-tricarboxylic acid molecule has multiple carboxyl groups in its molecular structure. These strong chelating groups can react with Ca in water. 2+ Mg 2+The scale-forming cations form stable water-soluble complexes, preventing these ions from combining with anions such as carbonate and sulfate to form scale. Their aromatic ring structure can embed into the lattice of growing scale crystals, causing lattice distortion and preventing the formation of dense, firm scale. The sulfonic acid groups on the modified sulfonated silica sol can further disperse the formed microcrystals through electrostatic repulsion and steric hindrance, preventing their aggregation and deposition. The synergistic effect of these two factors enhances the scale inhibition performance of the scale inhibitor. The quaternary ammonium salt groups in dimethyl diallyl ammonium chloride can strongly adsorb onto the negatively charged clay mineral surface through electrostatic interactions, effectively inhibiting the hydration, swelling, and dispersion of clay. Furthermore, the aromatic amide structure can prevent water molecules from entering the interlayer through hydrophobic interactions. This invention enhances the anti-swelling performance of scale inhibitors and anti-swelling agents. The inorganic siloxane backbone in the modified sulfonated silica sol significantly increases the glass transition temperature and thermal decomposition temperature of the organic polymer chain, preventing chain breakage or degradation at high temperatures. The rigid benzene ring structure also enhances the thermal stability of the polymer backbone, thus improving the temperature resistance of the scale inhibitor and anti-swelling agent. As a multifunctional crosslinking monomer, the modified sulfonated silica sol can form a three-dimensional interpenetrating network structure with the organic molecular chain. This crosslinking structure reduces the solubility of the polymer chain in water, enabling it to resist the shearing and scouring of high-speed fluids and enhancing the water wash resistance of the scale inhibitor and anti-swelling agent. Furthermore, the scale inhibitor and anti-swelling agent of this invention does not contain phosphorus, heavy metals, or highly toxic substances, making it scientifically sound, environmentally friendly, and easy to use. Attached Figure Description

[0014] Figure 1 It is the synthesis reaction formula for modified sulfonated silica sol; Figure 2 It is the synthetic reaction formula for modified 2-aminobenzene-1,3,5-tricarboxylic acid. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] Example 1 (1) Add 1g of (3-mercaptopropyl)trimethoxysilane to 3g of deionized water, sonicate for 20min, and then slowly add 6g of 30% hydrogen peroxide solution at a rate of 3s / drop under stirring. After the addition is complete, adjust the pH of the solution to 6.0 with 1mol / L hydrochloric acid. Stir continuously at room temperature for 24h. After the reaction is complete, add 6g of anhydrous sodium sulfite to the system, stir for 30min, dialyze for 5 days using an 8000Da dialysis bag, use deionized water as the external dialysis solution, change the water 3 times a day, freeze dry at -75℃ for 48h to obtain sulfonated silica sol. (2) Add 45 mL of anhydrous ethanol and 15 mL of deionized water to the reactor, mix to prepare a solution, then add 0.8 g of sulfonated silica sol, sonicate for 35 min, then add 0.65 g of γ-methacryloyloxypropyltrimethoxysilane, and adjust the pH of the system to 4 with 1 mol / L hydrochloric acid. Stir and reflux at 55 °C for 6 h. After the reaction, dialyze for 2 days using an 8000 Da dialysis bag, using anhydrous ethanol as the dialysate, changing the ethanol 3 times a day. Freeze-dry at -75 °C for 48 h to obtain the modified sulfonated silica sol, as shown below. Figure 1 As shown; (3) Add 1.1g of ammonium thiocyanate to 20mL of acetonitrile solvent, mix well, and slowly add 1.6g of 4-vinylbenzoyl chloride dropwise while stirring at room temperature. After the addition is complete, stir the reaction for 4h. After the reaction is complete, filter, remove the solvent by rotary evaporation, concentrate under reduced pressure, and purify to obtain intermediate 1. (4) Add 1.7 g of intermediate 1 and 2.5 g of 2-aminophenyl-1,3,5-carboxylic acid to 25 mL of N,N-dimethylformamide solvent, stir and mix, then add 0.8 g of triethylamine, and react at 40 °C for 8 h. After the reaction is complete, cool the reaction solution to room temperature, and slowly pour in 150 mL of deionized water while stirring. Filter, wash, recrystallize, and dry to obtain modified 2-aminophenyl-1,3,5-tricarboxylic acid, as shown below. Figure 2 As shown; (5) 12 parts by weight of acrylamide, 6 parts by weight of dimethyl diallyl ammonium chloride and 1 part by weight of modified 2-aminobenzene-1,3,5-tricarboxylic acid were added sequentially to 70 parts by weight of deionized water and stirred at 200 r / min until uniformly dispersed. Then, 0.5 parts by weight of modified sulfonated silica sol were added and stirred for 40 min to obtain a prepolymer solution. Nitrogen gas was then introduced for 20 min and the temperature was raised to 55°C. 0.08 parts by weight of azobisisobutyramidine hydrochloride was added dropwise at a rate of 1 mL / min. After the addition was completed, the reaction was kept at the temperature for 4 h. After the reaction was completed, the solution was cooled to room temperature to obtain a scale inhibitor and anti-swelling agent.

[0017] Example 2 (1) Add 1.1g of (3-mercaptopropyl)trimethoxysilane to 4g of deionized water, disperse by ultrasonication for 30min, and then slowly add 6.1g of 30% hydrogen peroxide solution at a rate of 4s / drop under stirring. After the addition is complete, adjust the pH of the solution to 6.0 with 1mol / L hydrochloric acid. Stir continuously at room temperature for 28h. After the reaction is complete, add 6.1g of anhydrous sodium sulfite to the system, stir for 35min, dialyze with a 10000Da dialysis bag for 7 days, use deionized water as the external dialysis solution, change the water 4 times a day, freeze dry at -85℃ for 72h to obtain sulfonated silica sol; (2) Add 50 mL of anhydrous ethanol and 20 mL of deionized water to the reactor, mix to prepare a solution, then add 0.9 g of sulfonated silica sol, sonicate for 45 min, then add 0.72 g of γ-methacryloyloxypropyltrimethoxysilane, and adjust the pH of the system to 4 with 1 mol / L hydrochloric acid. Stir and reflux at 65 °C for 8 h. After the reaction is completed, use a 10000 Da dialysis bag for 3 days, use anhydrous ethanol as the dialysis fluid, change the ethanol 4 times a day, freeze dry at -85 °C for 72 h to obtain modified sulfonated silica sol. (3) Add 1.2g of ammonium thiocyanate to 30mL of acetonitrile solvent, mix well, and slowly add 1.7g of 4-vinylbenzoyl chloride dropwise while stirring at room temperature. After the addition is complete, stir the reaction for 6h. After the reaction is complete, filter, remove the solvent by rotary evaporation, concentrate under reduced pressure, and purify to obtain intermediate 1. (4) Add 1.8 g of intermediate 1 and 2.6 g of 2-aminophenyl-1,3,5-carboxylic acid to 35 mL of N,N-dimethylformamide solvent, stir and mix, then add 0.85 g of triethylamine, react at 50 °C for 12 h, after the reaction is completed, cool the reaction solution to room temperature, and slowly pour in 160 mL of deionized water while stirring, filter, wash, recrystallize and dry to obtain modified 2-aminophenyl-1,3,5-tricarboxylic acid; (5) 15 parts by weight of acrylamide, 8 parts by weight of dimethyl diallyl ammonium chloride and 3 parts by weight of modified 2-aminobenzene-1,3,5-tricarboxylic acid were added sequentially to 80 parts by weight of deionized water and stirred at 300 r / min until uniformly dispersed. Then, 0.8 parts by weight of modified sulfonated silica sol were added and stirred for another 50 min to obtain a prepolymer solution. Nitrogen gas was then introduced for 30 min and the temperature was raised to 60°C. 0.12 parts by weight of azobisisobutyramidine hydrochloride was added dropwise at a rate of 2 mL / min. After the addition was completed, the reaction was kept at the temperature for 6 h. After the reaction was completed, the solution was cooled to room temperature to obtain a scale inhibitor and anti-swelling agent.

[0018] Example 3 (1) Add 1.05g of (3-mercaptopropyl)trimethoxysilane to 3.5g of deionized water, disperse by ultrasonication for 25min, and then slowly add 6.05g of 30% hydrogen peroxide solution at a rate of 3s / drop under stirring. After the addition is complete, adjust the pH of the solution to 6.0 with 1mol / L hydrochloric acid. Stir continuously at room temperature for 26h. After the reaction is complete, add 6.05g of anhydrous sodium sulfite to the system, stir for 33min, dialyze with a 9000Da dialysis bag for 6 days, use deionized water as the external dialysis solution, change the water 3 times a day, freeze dry at -80℃ for 60h to obtain sulfonated silica sol; (2) Add 48 mL of anhydrous ethanol and 18 mL of deionized water to the reactor, mix to prepare a solution, then add 0.85 g of sulfonated silica sol, sonicate for 40 min, then add 0.68 g of γ-methacryloyloxypropyltrimethoxysilane, and adjust the pH of the system to 4 with 1 mol / L hydrochloric acid. Stir and reflux at 50 °C for 7 h. After the reaction is completed, dialyze for 2 days using a 9000 Da dialysis bag, using anhydrous ethanol as the dialysate, changing the ethanol 3 times a day, and freeze-dry at -80 °C for 60 h to obtain modified sulfonated silica sol. (3) Add 1.15g of ammonium thiocyanate to 25mL of acetonitrile solvent, mix well, and slowly add 1.65g of 4-vinylbenzoyl chloride dropwise while stirring at room temperature. After the addition is complete, stir the reaction for 5h. After the reaction is complete, filter, remove the solvent by rotary evaporation, concentrate under reduced pressure, and purify to obtain intermediate 1. (4) Add 1.75 g of intermediate 1 and 2.55 g of 2-aminophenyl-1,3,5-carboxylic acid to 30 mL of N,N-dimethylformamide solvent, stir and mix, then add 0.82 g of triethylamine, react at 45 °C for 10 h, after the reaction is completed, cool the reaction solution to room temperature, and slowly pour in 155 mL of deionized water while stirring, filter, wash, recrystallize and dry to obtain modified 2-aminophenyl-1,3,5-tricarboxylic acid; (5) 13 parts by weight of acrylamide, 7 parts by weight of dimethyl diallyl ammonium chloride and 2 parts by weight of modified 2-aminobenzene-1,3,5-tricarboxylic acid were added sequentially to 75 parts by weight of deionized water and stirred at 250 r / min until uniformly dispersed. Then, 0.6 parts by weight of modified sulfonated silica sol were added and stirred for 45 min to obtain a prepolymer solution. Nitrogen gas was then introduced for 25 min and the temperature was raised to 58°C. 0.1 parts by weight of azobisisobutyramidine hydrochloride was added dropwise at a rate of 1 mL / min. After the addition was completed, the reaction was kept at the temperature for 5 h. After the reaction was completed, the solution was cooled to room temperature to obtain a scale inhibitor and anti-swelling agent.

[0019] Example 4 (1) Add 1.02 g of (3-mercaptopropyl)trimethoxysilane to 3.2 g of deionized water, disperse by ultrasonication for 22 min, and then slowly add 6.02 g of 30% hydrogen peroxide solution at a rate of 3 s / drop under stirring. After the addition is complete, adjust the pH of the solution to 6.0 with 1 mol / L hydrochloric acid. Stir continuously at room temperature for 25 h. After the reaction is complete, add 6.02 g of anhydrous sodium sulfite to the system, stir for 32 min, dialyze with an 8000 Da dialysis bag for 5 days, use deionized water as the external dialysis solution, change the water 3 times a day, freeze dry at -78℃ for 54 h to obtain sulfonated silica sol; (2) Add 46 mL of anhydrous ethanol and 16 mL of deionized water to the reactor, mix to prepare a solution, then add 0.82 g of sulfonated silica sol, sonicate for 38 min, then add 0.66 g of γ-methacryloyloxypropyltrimethoxysilane, and adjust the pH of the system to 4 with 1 mol / L hydrochloric acid. Stir and reflux at 58 °C for 6 h. After the reaction is completed, dialyze for 2 days using an 8000 Da dialysis bag, using anhydrous ethanol as the dialysate, changing the ethanol 3 times a day, and freeze-dry at -78 °C for 54 h to obtain modified sulfonated silica sol. (3) Add 1.12 g of ammonium thiocyanate to 22 mL of acetonitrile solvent, mix well, and slowly add 1.62 g of 4-vinylbenzoyl chloride dropwise while stirring at room temperature. After the addition is complete, stir the reaction for 4 h. After the reaction is complete, filter, remove the solvent by rotary evaporation, concentrate under reduced pressure, and purify to obtain intermediate 1. (4) Add 1.72 g of intermediate 1 and 2.52 g of 2-aminophenyl-1,3,5-carboxylic acid to 28 mL of N,N-dimethylformamide solvent, stir and mix, then add 0.81 g of triethylamine, react at 42 °C for 9 h, after the reaction is completed, cool the reaction solution to room temperature, and slowly pour in 152 mL of deionized water while stirring, filter, wash, recrystallize and dry to obtain modified 2-aminophenyl-1,3,5-tricarboxylic acid; (5) 13 parts by weight of acrylamide, 6 parts by weight of dimethyl diallyl ammonium chloride and 2 parts by weight of modified 2-aminobenzene-1,3,5-tricarboxylic acid were added sequentially to 72 parts by weight of deionized water and stirred at 200 r / min until uniformly dispersed. Then, 0.6 parts by weight of modified sulfonated silica sol were added and stirred for 42 min to obtain a prepolymer solution. Nitrogen gas was then introduced for 22 min and the temperature was raised to 56°C. 0.09 parts by weight of azobisisobutyramidine hydrochloride was added dropwise at a rate of 1 mL / min. After the addition was completed, the reaction was kept at the temperature for 4 h. After the reaction was completed, the solution was cooled to room temperature to obtain a scale inhibitor and anti-swelling agent.

[0020] Example 5 (1) Add 1.08 g of (3-mercaptopropyl)trimethoxysilane to 3.8 g of deionized water, disperse by ultrasonication for 28 min, and then slowly add 6.08 g of 30% hydrogen peroxide solution at a rate of 4 s / drop under stirring. After the addition is complete, adjust the pH of the solution to 6.0 with 1 mol / L hydrochloric acid. Stir continuously at room temperature for 27 h. After the reaction is complete, add 6.08 g of anhydrous sodium sulfite to the system, stir for 34 min, dialyze with a 10000 Da dialysis bag for 7 days, use deionized water as the external dialysis solution, change the water 4 times a day, freeze dry at -82℃ for 66 h to obtain sulfonated silica sol; (2) Add 49 mL of anhydrous ethanol and 19 mL of deionized water to the reactor, mix to prepare a solution, then add 0.88 g of sulfonated silica sol, sonicate for 42 min, then add 0.7 g of γ-methacryloyloxypropyltrimethoxysilane, and adjust the pH of the system to 4 with 1 mol / L hydrochloric acid. Stir and reflux at 62 °C for 8 h. After the reaction is completed, dialyze for 3 days using a 10000 Da dialysis bag, using anhydrous ethanol as the dialysate, changing the ethanol 4 times a day, and freeze-dry at -82 °C for 66 h to obtain modified sulfonated silica sol. (3) Add 1.18 g of ammonium thiocyanate to 28 mL of acetonitrile solvent, mix well, and slowly add 1.68 g of 4-vinylbenzoyl chloride dropwise while stirring at room temperature. After the addition is complete, stir the reaction for 6 h. After the reaction is complete, filter, remove the solvent by rotary evaporation, concentrate under reduced pressure, and purify to obtain intermediate 1. (4) Add 1.78 g of intermediate 1 and 2.58 g of 2-aminophenyl-1,3,5-carboxylic acid to 33 mL of N,N-dimethylformamide solvent, stir and mix, then add 0.84 g of triethylamine, react at 48 °C for 11 h, after the reaction is completed, cool the reaction solution to room temperature, and slowly pour in 158 mL of deionized water while stirring, filter, wash, recrystallize and dry to obtain modified 2-aminophenyl-1,3,5-tricarboxylic acid; (5) 14 parts by weight of acrylamide, 8 parts by weight of dimethyl diallyl ammonium chloride and 3 parts by weight of modified 2-aminobenzene-1,3,5-tricarboxylic acid were added sequentially to 78 parts by weight of deionized water and stirred at 300 r / min until uniformly dispersed. Then, 0.7 parts by weight of modified sulfonated silica sol were added and stirred for 48 min to obtain a prepolymer solution. Nitrogen gas was then introduced for 28 min and the temperature was raised to 59°C. 0.11 parts by weight of azobisisobutyramidine hydrochloride was added dropwise at a rate of 2 mL / min. After the addition was completed, the reaction was kept at the temperature for 6 h. After the reaction was completed, the solution was cooled to room temperature to obtain a scale inhibitor and anti-swelling agent.

[0021] Comparative Example 1 The main difference between this comparative example and Example 5 is that no modified 2-aminobenzene-1,3,5-tricarboxylic acid is added.

[0022] Comparative Example 2 The main difference between this comparative example and Example 5 is that no modified sulfonated silica sol is added.

[0023] Performance testing (1) Scale inhibition performance test: The scale inhibition rate of the scale inhibitors and anti-swelling agents prepared in Examples 1-5 and Comparative Examples 1-2 on calcium carbonate was tested according to the standard SY / T5673-2020. The test results are shown in Table 1.

[0024] Table 1: Scale Inhibition Performance Test Group Scale inhibition rate (%) Example 1 94.35 Example 2 95.32 Example 3 94.92 Example 4 94.68 Example 5 95.11 Comparative Example 1 73.24 Comparative Example 2 84.69 As can be seen from Table 1, the scale inhibitors and anti-swelling agents prepared in Examples 1-5 have good scale inhibition performance.

[0025] (2) Anti-swelling performance test: According to the SY / T5971-2016 standard, 0.5g of sodium bentonite and 10mL of the scale inhibitor and anti-swelling agent prepared in Examples 1-5 and Comparative Examples 1-2 were added to centrifuge tubes respectively, mixed thoroughly, allowed to stand at room temperature for 2h, centrifuged, and the swelling volume of sodium bentonite was measured and recorded as V1; according to the above method, the scale inhibitor and anti-swelling agent prepared in Examples 1-5 and Comparative Examples 1-2 were replaced with deionized water, and the swelling volume of sodium bentonite was measured and recorded as V2; according to the above method, the scale inhibitor and anti-swelling agent prepared in Examples 1-5 and Comparative Examples 1-2 were replaced with kerosene, and the swelling volume of sodium bentonite was measured and recorded as V0; the anti-swelling rate was calculated according to the formula Anti-swelling rate = (V2-V1) / (V2-V0)×100%. The test results are shown in Table 2.

[0026] Table 2: Anti-swelling performance test Group Anti-expansion rate (%) Example 1 97.2 Example 2 98.0 Example 3 97.5 Example 4 97.3 Example 5 97.8 Comparative Example 1 90.2 Comparative Example 2 87.6 As can be seen from Table 2, the scale inhibitors and anti-swelling agents prepared in Examples 1-5 have good anti-swelling properties.

[0027] (3) Temperature resistance test: Weigh 3.2g of the scale inhibitor and anti-swelling agent prepared in Examples 1-5 and Comparative Examples 1-2 respectively, add 96.8g of deionized water, stir and dissolve evenly to prepare a working solution with a mass concentration of 0.8%, and place it in an oven at 80℃, 100℃ and 120℃ for 24h respectively. Then take it out and cool it to room temperature. Test the anti-swelling rate of the cooled working solution according to the test method in test method (2). The test results are shown in Table 3.

[0028] Table 3: Temperature Resistance Test

[0029] As can be seen from Table 3, the scale inhibitors and anti-swelling agents prepared in Examples 1-5 have good temperature resistance.

[0030] (4) Water wash resistance test: According to the SY / T5971-2016 standard, the supernatant after centrifugation in test method (2) was taken with a pipette, 10 mL of deionized water was added, and the mixture was thoroughly mixed. The mixture was allowed to stand at room temperature for 2 hours, centrifuged, and the above steps were repeated twice. The expansion volume of sodium bentonite in water was measured and recorded as V3. V1 was the scale inhibitor and anti-swelling agent prepared in Examples 1-5 and Comparative Examples 1-2 that was added to the centrifuge tube in test method (2), 0.5 g of sodium bentonite and 10 mL of scale inhibitor and anti-swelling agent prepared in Examples 1-5 and Comparative Examples 1-2 were thoroughly mixed, allowed to stand at room temperature for 2 hours, centrifuged, and the expansion volume of sodium bentonite was measured. The water wash resistance rate was calculated according to the formula water wash resistance rate = (V1 / V3) × 100%. The test results are shown in Table 4.

[0031] Table 4: Water Wash Resistance Test Group Washing resistance (%) Example 1 86.94 Example 2 88.10 Example 3 87.49 Example 4 87.26 Example 5 87.76 Comparative Example 1 79.54 Comparative Example 2 75.23 As can be seen from Table 4, the scale inhibitors and anti-swelling agents prepared in Examples 1-5 have good water wash resistance.

[0032] The comparison shows that Comparative Example 1, without the addition of modified 2-aminobenzene-1,3,5-tricarboxylic acid, lacks several carboxylate groups, which affects the Ca... 2+ Mg 2+ The loss of scale-forming cation chelation and lattice distortion effects, coupled with the absence of strong hydrophobic adsorption provided by the aromatic amide structure and the rigid benzene ring skeleton, weakens the adsorption capacity for hydrogen bonds formed on the surface of clay minerals. The thermal stability of the polymer molecular chain also decreases, leading to a decline in the scale inhibition, anti-swelling, temperature resistance, and water washability of Comparative Example 1. Comparative Example 2, lacking modified sulfonated silica sol, lacks polymerizable nano-silica sol crosslinking points, making it unable to form a slight three-dimensional network structure. The adsorption film is easily detached, resulting in weak adsorption. Furthermore, it lacks the scale inhibition and dispersion ability of sulfonic acid groups for scale particles and the thermal stability of the siloxane skeleton. Therefore, the scale inhibition, anti-swelling, temperature resistance, and water washability of Comparative Example 2 also decline.

[0033] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0034] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0035] Those skilled in the art should understand that the above descriptions are merely several specific embodiments of the present invention, and not all embodiments.

Claims

1. An antiscalant and anti-sweller, characterized in that, It comprises the following weight components: 12-15 parts by weight of acrylamide, 6-8 parts by weight of dimethyl diallyl ammonium chloride, 0.5-0.8 parts by weight of modified sulfonated silica sol, 1-3 parts by weight of modified 2-aminobenzene-1,3,5-tricarboxylic acid, 0.08-0.12 parts by weight of azobisdimethylamidinium hydrochloride, 70-80 parts by weight of deionized water.

2. The scale and swell control agent of claim 1, wherein The preparation method of the modified sulfonated silica sol is: Step one: add (3-mercaptopropyl) trimethoxysilane to deionized water, ultrasonic dispersion for 20-30 min, then slowly drop 30% mass fraction hydrogen peroxide solution at a speed of 3-4 s / drop under stirring, after dropping, adjust the pH of the solution to 6.0 with 1 mol / L hydrochloric acid, continue stirring at room temperature for 24-28 h, after the reaction is completed, add anhydrous sodium sulfite to the system, stir for 30-35 min, use 8000-10000 Da dialysis bag to dialyze for 5-7 days, use deionized water as the dialysis external solution, change water 3-4 times a day, freeze-dry at-75 to-85℃ for 48-72 h to obtain sulfonated silica sol; Step two: add 45-50 mL of anhydrous ethanol and 15-20 mL of deionized water to the reactor to prepare a solution, then add 0.8-0.9 g of sulfonated silica sol, ultrasonic treatment for 35-45 min, then add 0.65-0.72 g of γ-methacryloyloxypropyltrimethoxysilane, and adjust the pH of the system to 4 with 1 mol / L hydrochloric acid, stir and reflux at 55-65℃ for 6-8 h, after the reaction is completed, dialyze using an 8000-10000 Da dialysis bag, use anhydrous ethanol as the dialysis external solution, change ethanol 3-4 times a day, freeze-dry at-75 to-85℃ for 48-72 h to obtain modified sulfonated silica sol.

3. The scale and corrosion inhibitor of claim 2, wherein, The amount ratio of deionized water, (3-mercaptopropyl) trimethoxysilane, 30% mass fraction hydrogen peroxide solution, and anhydrous sodium sulfite in step one is (3-4 g):(1-1.1 g):(6-6.1 g):(6-6.1 g).

4. The scale and corrosion inhibitor of claim 2, wherein, The dialysis time in step two is 2-3 days.

5. The scale and corrosion inhibitor of claim 1, wherein, The preparation method of the modified 2-aminobenzene-1,3,5-tricarboxylic acid is: S1: add ammonium thiocyanate to acetonitrile solvent, mix uniformly, slowly drop 4-vinylbenzoyl chloride under stirring at room temperature, after dropping, stir for 4-6 h, after the reaction is completed, filter, remove the solvent by rotary evaporation, concentrate under reduced pressure, purify to obtain intermediate 1; S2: add intermediate 1 and 2-aminobenzene-1,3,5-carboxylic acid to N,N-dimethylformamide solvent, stir and mix, then add triethylamine, react at 40-50℃ for 8-12 h, after the reaction is completed, cool the reaction liquid to room temperature, slowly pour into deionized water under stirring, filter, wash, recrystallize, dry to obtain modified 2-aminobenzene-1,3,5-tricarboxylic acid.

6. The scale and corrosion inhibitor of claim 5, wherein, The amount ratio of acetonitrile, ammonium thiocyanate, 4-vinylbenzoyl chloride in S1 is (20-30 mL):(1.1-1.2 g):(1.6-1.7 g).

7. The scale and corrosion inhibitor of claim 5, wherein The amount ratio of N,N-dimethylformamide, intermediate 1, 2-amino benzene-1,3,5-carboxylic acid, triethylamine, deionized water in S2 is (25-35 mL):(1.7-1.8 g):(2.5-2.6 g):(0.8-0.85 g):(150-160 mL).

8. A process for the preparation of the scale and corrosion inhibitor as claimed in any one of claims 1 to 7, wherein said process comprises the steps of: The preparation method of the scale and swelling inhibitor is as follows: acrylamide, dimethyl diallyl ammonium chloride and modified 2-amino benzene-1,3,5-tricarboxylic acid are sequentially added into deionized water, and stirred at a speed of 200-300 r / min until uniformly dispersed, then modified sulfonated silica sol is added, and continues to be stirred for 40-50 min to obtain a prepolymer solution, then nitrogen is passed for 20-30 min, and the temperature is raised to 55-60 ℃, and azobisdimethylaminoformamidine hydrochloride is added dropwise at a speed of 1-2 mL / min, after the dropwise addition is completed, the reaction is preserved for 4-6 h, after the reaction is completed, the temperature is cooled to room temperature, and the scale and swelling inhibitor is obtained.

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