Waterproof lock high temperature resistant and high salt resistant fracturing thickening agent and preparation method thereof

Abstract

The present application relates to the technical field of oil and gas stimulation, and is a water-lock-proof high-temperature-resistant and high-salt-resistant fracturing thickening agent and a preparation method thereof, wherein the former is obtained by the following method: mixing acrylamide hydrophilic monomers, sodium acrylate hydrophilic monomers and polymerizable monomers containing amphiphilic groups to obtain a mixed solution A; dissolving fluorine-substituted unsaturated monomers containing sulfonic acid groups in water to obtain an aqueous solution B; dissolving a low-temperature composite initiator in water to obtain an aqueous solution C; simultaneously adding the aqueous solution B and the aqueous solution C into the mixed solution A to react, and then cutting, drying, crushing and sieving the obtained colloidal product to obtain the water-lock-proof high-temperature-resistant and high-salt-resistant fracturing thickening agent. By simultaneously introducing the polymerizable monomers containing amphiphilic groups and the fluorine-substituted unsaturated monomers containing sulfonic acid groups into the fracturing thickening agent, the present application not only greatly improves the high-temperature resistance and high-salt resistance of the thickening agent before gel breaking, but also has the characteristics of good water-lock-proof performance, small dosage, sufficient temperature resistance and shear resistance.

Description

Technical Field

[0001] This invention relates to the field of oil and gas production enhancement technology, and is a waterproof, high-temperature resistant, and high-salt fracturing thickener and its preparation method. Background Technology

[0002] Hydraulic fracturing, as a crucial technology for enhancing unconventional resources such as tight oil and shale oil and gas, has been widely applied and achieved significant success both domestically and internationally, making a substantial contribution to increasing global oil and gas reserves and production. Fracturing fluid, as the key working fluid in hydraulic fracturing, directly determines the efficiency and effectiveness of fracturing operations. Thickeners, as important main agents in fracturing fluids, are crucial for ensuring the overall performance of the fracturing fluid system. Due to their advantages such as good drag reduction, strong thickening ability, low residue content, and insensitivity to bacteria, synthetic polymers have become one of the mainstream directions for the research and application of fracturing fluid thickeners. However, as the development of unconventional oil and gas resources continues to delve deeper into complex formations with high water content, high temperature, and high salinity, traditional fracturing fluid systems based on synthetic polymers face numerous problems that urgently need to be addressed. On the one hand, high water cut conditions lead to severe problems in actual oil and gas production, such as significant water-locking damage, poor adaptability of traditional fracturing fluids, and a significant decline in production well productivity, even resulting in shutdown. On the other hand, due to the effects of high temperature and high salinity, traditional fracturing fluid systems generally face problems such as poor temperature resistance, insufficient proppant carrying capacity, and high construction costs. To address these issues, scientists and engineers have conducted extensive research and development, significantly improving the overall performance of fracturing fluids.

[0003] Chinese patent document CN104927830B discloses a waterproof fracturing fluid and its preparation method. It combines a specific ratio of hydroxypropyl guar gum, soda ash, clay stabilizer, bactericide, waterproofing agent (a mixture of hexadecyl dimethyl ammonium bromide, octylphenol polyoxyethylene ether, and fluorocarbon surfactant), and water to address the water-locking effect caused by the inability of traditional fracturing fluids to effectively reduce the surface tension of the filtrate and the interfacial tension between oil and water, thereby improving the permeability of the oil and gas phases. After reacting with an aqueous solution of borax or an organic boron solution, this waterproof fracturing fluid can achieve a drainage rate of 90% to 93% and reduce the core damage rate to 17% to 14%.

[0004] Chinese patent document CN107345129A discloses a waterproofing agent and its preparation method. The method involves using cyclohexane as a solvent, glyceryl monostearate and hexadecyltriethylammonium bromide as emulsifiers, ammonium persulfate as an initiator, and ammonium metavanadate and neodymium oxide as catalysts to polymerize acrylamide with liquid polybutadiene to form a highly active surfactant. β-sitosterol is used as a surfactant additive, and γ-aminopropyltriethoxysilane is used to improve the structural properties and increase the adhesion to the reservoir. The surface tension of a 1% aqueous solution is as low as 18.7 mN / m, and the interfacial tension is as low as 0.31 mN / m.

[0005] Chinese patent document CN113528099A discloses a waterproofing agent and its preparation method. By combining nonionic surfactant, anionic surfactant, amphoteric surfactant, low carbon alcohol and water, it can reduce the surface tension to 22.2 mN / m, reduce the oil-water interfacial tension to 5.8×10-3 mN / m, and change the contact angle of clean water on the rock surface from 52.9° to 73.9°.

[0006] Chinese patent document CN114890920B discloses a waterproofing agent and its preparation method. It is prepared by reacting 8-aminonaphthalene-1,3,6-trisulfonic acid disodium salt with bromododecane in a mixed solvent composed of formic acid, formaldehyde and methanol. It has the characteristics of wide availability of raw materials, simple preparation process, no pollution and no by-products. The surface tension of the waterproofing agent is less than 27 mN / m and the interfacial tension is less than 0.08 mN / m at a concentration of 0.5 wt%. Chinese patent CN114958330B discloses a waterproofing interlocking agent for fracturing and its preparation method. It is prepared by synergistic combination of sodium p-perfluorononenoxybenzenesulfonate, perfluorooctyl sulfonyl polyoxyethylene ether, and sodium dodecylbenzenesulfonate in the presence of formate and chloride salts. It has the characteristics of low surface tension, strong hydrophobicity, strong temperature resistance, strong chemical stability, and strong surface interaction with rocks. The surface tension is less than 27 mN / m and the hydrophilic contact angle is 108.2°, which is suitable for waterproofing interlocking in sensitive tight gas reservoirs.

[0007] Chinese patent document CN115872892B discloses a drilling waterproofing lock monomer, a drilling waterproofing lock, its preparation method, and its application. It prepares a high-molecular-weight surfactant through the polymerization reaction of monomers containing alkenylamide, alkenylsulfonic acid, and alkenylsiloxane structural units with a self-made waterproofing lock monomer containing benzene ring structural units. The hydrophobicity, rigidity, and steric hindrance of the benzene ring enhance the salt and temperature resistance of the waterproofing lock. The hydrolysis of the siloxane unit strengthens its adsorption to reservoir rocks. The dipole interaction between the imidazole ionic liquid unit and water molecules enhances surface activity and the ability to alter rock wettability. At a dosage of 0.5%, the surface tension at room temperature is as low as 17.35 mN / m, the oil-water interfacial tension is as low as 0.30 mN / m, and the hydrophilic contact angle at 80°C can reach 57.28°. However, the patent does not address whether the obtained waterproofing sealant is suitable for fracturing thickeners and its related performance in fracturing, and the hydrophilic contact angle (still maintained under strong hydrophilic conditions) indicates that its wetting improvement ability is limited, and it also does not address the related performance of temperature resistance and shear resistance.

[0008] Chinese patent document CN115947891B discloses a temperature- and salt-resistant, fast-dissolving polyacrylamide, its preparation method, and its applications. It modifies polyacrylamide by introducing a benzene-ring-containing rigid, temperature- and salt-resistant monomer and a fluorine-containing cationic hydrophobic monomer onto acrylamide monomer and sodium acrylate monomer. Narrowly distributed, low- to medium-molecular-weight polyacrylamide is prepared using a rapid-dissolving synthesis technology and ATRP polymerization. Under clean water conditions, 0.03% powder can viscous within 48 seconds, with a mineralization of 100,000 mg / L (calcium and magnesium ions 20,000 mg / L) and a maximum viscosity of 13.57-27.75 mPa·s at room temperature for 0.1%-0.3% powder. However, this patent does not address properties beneficial for waterproofing, such as the surface tension, oil-water interfacial tension, and contact angle of the broken-up liquid after delamination.

[0009] Chinese patent document CN116285936B discloses a high-temperature resistant, salt-resistant, and fast-dissolving fracturing fluid thickener and its preparation method. This method modifies polyacrylamide by introducing carboxylic acid-containing monomers, salt-resistant monomers containing benzenesulfonic acid or benzoic acid groups, and fluorinated cationic hydrophobic monomers into the polyacrylamide molecular structure. The carboxylic acid or sulfonic acid-containing monomers improve the thickener's solubility and salt resistance, the monomers containing benzene ring groups improve the thickener's temperature resistance and shear strength, and the fluorinated cationic hydrophobic monomers improve the thickener's viscosity and temperature resistance and shear strength. Under clean water conditions, 0.03% powder can form a viscous layer within 47 seconds. At a mineralization of 120,000 mg / L (calcium and magnesium ions 10,000 mg / L) and at room temperature, the viscosity of 0.1%-0.2% powder reaches a maximum of 15.49-27.86 mPa·s. However, the patent does not address properties beneficial to waterproof locks, such as the surface tension of the debonded liquid after debonding, the oil-water interfacial tension, and the contact angle.

[0010] Zhang Peng et al. of China Oilfield Services Co., Ltd. prepared a fluorine-free surfactant using high fatty acids and diethanolamine as raw materials, and combined it with cationic surfactant and organosilicon defoamer to form a new type of fluorine-free waterproof lock agent. When the dosage is 0.5%, the surface tension of the aqueous solution is less than 15mN / m, which can change the contact angle of hydrophilic sandstone surface from 34.4° to 85.3°. At the same time, it has good temperature and salt resistance (Zhang Peng et al., Development and performance evaluation of new waterproof lock agent for low-permeability reservoirs, Petrochemical Application, 2023, 42(12)). Jin Jiafeng et al. from China University of Petroleum (East China) prepared a waterproof locking agent FWB by using high-hydrogen-content block silicone oil as the main agent and compounding it with organosilicon surfactants, defoamers and other additives. When the amount added is 1.0%, the surface tension can be reduced to 22.28 mN / m, the hydrophilic contact angle of the core surface can be changed from 29° to 120°, and the core permeability recovery rate can be increased to 89.3% (Jin Jiafeng et al., Research and evaluation of new block silicone oil waterproof locking agent, Xinjiang Petroleum and Natural Gas, 2023, 19(03)).

[0011] Chu Qi of Sinopec Petroleum Engineering Technology Research Institute Co., Ltd. synthesized a waterproof lock agent SMFS-1 using alginic acid, hydroxyethyl ethylenediamine, epichlorohydrin and pentaerythritol as raw materials. When the amount is increased by 0.3%, the surface tension can be reduced to 25mN / m, the hydrophilic contact angle of the core surface can be changed from 38.97° to 81.62°, and the core permeability recovery rate can be increased to more than 80% (Chu Qi, An environmentally friendly non-foaming waterproof lock agent, Drilling Fluids and Completion Fluids, 2023, 19(03)). Chen Zhihao et al. from Yangtze University prepared a small-sized core-shell structured fluorinated nanoemulsion waterproofing agent M916 using nonylphenol polyoxyethylene ether, methyl isobutyl methanol, white oil and poly(methyl-3,3,3-trifluoropropylsiloxane) as raw materials. It can achieve deep waterproofing, change the wetting of the rock surface to neutral, and increase the core permeability recovery rate to 92.43% (Chen Zhihao et al., Research and application of nanoemulsion waterproofing agent for tight low-pressure gas reservoirs, Modern Chemical Industry, 2023, 152(09)).

[0012] Gong Hongliang of China Oilfield Services Corporation prepared a waterproofing lock agent FR-101 using methyl isobutyl acrylate, methacrylic acid and butyl 2-acrylate as raw materials. When the dosage is 1.2%, the surface tension can be reduced to 23.8 mN / m, which can change the surface wettability of the core thin section from hydrophilic to neutral wettability, and make the core permeability recovery rate reach more than 90% (Gong Hongliang, Preparation and performance evaluation of high efficiency waterproofing lock agent for drilling in low-permeability offshore oilfields, Chemical and Biological Engineering, 2023, 40(10)).

[0013] He Yiming of Yanchang Oilfield Co., Ltd. also prepared an emulsion waterproofing lock agent FRT-2 using methyl isobutyl acrylate, acrylic acid and butyl acrylate as raw materials. When the amount is increased by 1.0%, the surface tension can be reduced to 25mN / m, which can change the hydrophilic contact angle of the core surface from 39.6° to 91.3° and reduce the core water lock damage rate to below 20% (He Yiming, Research on a new type of emulsion waterproofing lock agent suitable for low permeability gas reservoirs, Chemical Engineer, 2024, 344(05)).

[0014] Cao Weijia et al. from Northeast Petroleum University prepared a short-chain fluorocarbon quaternary ammonium salt surfactant by reacting perfluorohexylsulfonyl fluoride, N,N-dimethylethylenediamine, and ethyl bromoacetate. They then compounded it with alkylbenzene sulfonate (ABS), sodium α-alkenyl sulfonate (A°S), and fatty alcohol oxyethylene ether sulfate (AES) to form a waterproofing lock agent. When the dosage was 0.5%, the oil-water interfacial tension of the aqueous solution could reach 0.299 mN / m and the surface tension could reach 20.23 mN / m. The contact angle of the hydrophilic surface could be changed from 28.097° to 67.225° (Cao Weijia et al., Performance Evaluation of Waterproofing Lock Agent Formulation in Low-Permeability Tight Gas Reservoirs, Petrochemical Technology, 2024).

[0015] In summary, the existing patents and published studies mainly involve compounding individual waterproofing agents with other substances to form fracturing fluid systems. These systems suffer from problems such as insufficient waterproofing and locking effects due to chromatographic separation risks, inadequate compatibility and synergy, and poor high-temperature and high-salt resistance. Consequently, they also result in low overall drainage rates, high reservoir damage rates, and large dosages. The studies do not address the issue of introducing monomers containing both high-salt and high-temperature resistant, waterproofing and locking groups into fracturing thickeners through special molecular structure design, thereby directly endowing them with waterproofing and locking functions and significantly improving their high-temperature and high-salt resistance. Summary of the Invention

[0016] This invention provides a waterproof, high-temperature resistant, and high-salt-resistant fracturing thickener and its preparation method, overcoming the shortcomings of the prior art. It can effectively solve the problems of weak waterproof and locking performance of existing compound fracturing fluid thickeners, large dosage under high temperature and high salt conditions, and insufficient temperature and shear resistance in existing compound fracturing fluid systems.

[0017] One of the technical solutions of this invention is achieved through the following measures: a waterproof, high-temperature resistant, and high-salt-resistant thickener, the raw materials of which include acrylamide hydrophilic monomer, sodium acrylate hydrophilic monomer, polymerizable monomer containing amphiphilic groups, and fluorinated unsaturated monomer containing sulfonic acid groups, wherein the mass ratio of acrylamide hydrophilic monomer, sodium acrylate hydrophilic monomer, polymerizable monomer containing amphiphilic groups, and fluorinated unsaturated monomer containing sulfonic acid groups is 1:0.15 to 0.3:0.02 to 0.08:0.003 to 0.008.

[0018] The following are further optimizations and / or improvements to one of the above-mentioned technical solutions:

[0019] The aforementioned polymerizable monomers containing amphiphilic groups are one or more of long-chain alkyl sulfonic acids or sulfonates, and N-alkyl-substituted acrylamides. The structural formula of the polymerizable monomers containing amphiphilic groups is as follows:

[0020]

[0021] Wherein, R1 is an amide group substituted with N-long-chain alkyl and short-chain alkyl sulfonic acid or sulfonate, and R2 is an amide group monosubstituted or disubstituted with N-long-chain alkyl.

[0022] The above R1 structure is:

[0023]

[0024] Where n is an integer from 11 to 19.

[0025] The above R2 structure is:

[0026]

[0027] Where n is an integer from 11 to 19.

[0028] The structural formula of the above-mentioned fluorinated unsaturated monomer containing sulfonic acid groups is as follows:

[0029]

[0030] One of them, where m is an integer from 0 to 1 and n is an integer from 4 to 9.

[0031] The above-mentioned waterproof, high-temperature resistant, and high-salt fracturing thickener is obtained according to the following method:

[0032] S1, dissolve the required amounts of acrylamide hydrophilic monomer, sodium acrylate hydrophilic monomer, and polymerizable monomer containing amphiphilic groups in water in sequence and mix and stir evenly to obtain a mixed solution A with a total monomer mass concentration of 18% to 28%.

[0033] S2, dissolve the required amount of fluorine-substituted unsaturated monomer containing sulfonic acid groups in water to obtain an aqueous solution B with a mass concentration of 2%;

[0034] S3, dissolve the required amount of low-temperature composite initiator in water until homogeneous to obtain an aqueous solution C with a mass concentration of 2.0%;

[0035] S4. After adjusting the pH of mixed solution A to 9 to 10 with a pH adjuster, mixed solution A and aqueous solution B are refrigerated for 25 min and then the temperature is lowered to -5℃. Then, aqueous solution B and aqueous solution C are added to mixed solution A at a rate of 0.2 mL / min. After initiating the polymerization reaction for 3.5 h to 4.5 h, a colloidal product is obtained.

[0036] S5, after chopping, drying, pulverizing and sieving the colloidal product, a waterproof, high-temperature resistant and high-salt-resistant thickener is obtained.

[0037] In step S4 above, the pH adjuster is one or more of sodium bicarbonate, sodium hydroxide, potassium hydroxide, citric acid, and glacial acetic acid, and the polymerization reaction temperature is -5℃ to 25℃.

[0038] In step S4 above, the low-temperature composite initiator is a mixture of sodium bisulfite, sodium persulfate and inorganic compound oxidant in a volume ratio of 1:1.2:0.12, wherein the volume ratio of the low-temperature composite initiator to mixed solution A is 1:300, and the inorganic compound oxidant is one or more of cerium ammonium sulfate and cerium ammonium nitrate.

[0039] The molecular weight range of the above-mentioned waterproof, high-temperature resistant, and high-salt fracturing thickener is 9.6 million Daltons to 16 million Daltons, and the size of the waterproof, high-temperature resistant, and high-salt fracturing thickener is ≥80 mesh.

[0040] The second technical solution of the present invention is achieved through the following measures: a method for preparing a waterproof, high-temperature resistant, and high-salt-resistant fracturing thickener, which is carried out according to the following method:

[0041] S1, dissolve the required amounts of acrylamide hydrophilic monomer, sodium acrylate hydrophilic monomer, and polymerizable monomer containing amphiphilic groups in water in sequence and mix and stir evenly to obtain a mixed solution A with a total monomer mass concentration of 18% to 28%.

[0042] S2, dissolve the required amount of fluorine-substituted unsaturated monomer containing sulfonic acid groups in water to obtain an aqueous solution B with a mass concentration of 2%;

[0043] S3, dissolve the required amount of low-temperature composite initiator in water until homogeneous to obtain an aqueous solution C with a mass concentration of 2.0%;

[0044] S4. After adjusting the pH of mixed solution A to 9 to 10 with a pH adjuster, mixed solution A and aqueous solution B are refrigerated for 25 min and then the temperature is lowered to -5℃. Then, aqueous solution B and aqueous solution C are added to mixed solution A at a rate of 0.2 mL / min. After initiating the polymerization reaction for 3.5 h to 4.5 h, a colloidal product is obtained.

[0045] S5, after chopping, drying, pulverizing and sieving the colloidal product, a waterproof, high-temperature resistant and high-salt-resistant thickener is obtained.

[0046] This invention introduces polymerizable monomers containing amphiphilic groups and fluorinated unsaturated monomers containing sulfonic acid groups into fracturing thickeners, which not only significantly improves the high temperature resistance and high salt resistance of the thickener before gel breaking, but also has the characteristics of good waterproofing and locking performance, low dosage, and sufficient temperature resistance and shear resistance. Detailed Implementation

[0047] This invention is not limited to the following embodiments, and specific implementation methods can be determined according to the technical solutions and actual conditions of this invention. Unless otherwise specified, all chemical reagents and chemical products mentioned in this invention are well-known and commonly used chemical reagents and chemical products in the prior art; unless otherwise specified, all percentages in this invention are mass percentages; unless otherwise specified, all solutions in this invention are aqueous solutions with water as the solvent, for example, hydrochloric acid solution is an aqueous solution of hydrochloric acid.

[0048] The present invention will be further described below with reference to embodiments:

[0049] Example 1: This waterproof, high-temperature resistant, and high-salt-resistant cracking thickener contains acrylamide hydrophilic monomer, sodium acrylate hydrophilic monomer, polymerizable monomer containing amphiphilic groups, and fluorinated unsaturated monomer containing sulfonic acid groups. The mass ratio of acrylamide hydrophilic monomer, sodium acrylate hydrophilic monomer, polymerizable monomer containing amphiphilic groups, and fluorinated unsaturated monomer containing sulfonic acid groups is 1:0.15 to 0.3:0.02 to 0.08:0.003 to 0.008.

[0050] This invention introduces both amphiphilic polymerizable monomers and fluorinated unsaturated monomers containing sulfonic acid groups into fracturing thickeners. This significantly improves the thickener's high-temperature and high-salt resistance before gel breaking, while simultaneously endowing it with a dual function of water-locking after gel breaking. It also addresses the problems of weak water-locking performance, high dosage under high-temperature and high-salt conditions, and insufficient temperature and shear resistance in existing compound fracturing fluid systems. This allows for effective fracturing at 150,000 mg / L salinity (10,000 mg / L calcium and magnesium ions) with 1.2% thickener at 180°C for 170 seconds. -1 After shearing for 2 hours under the specified conditions, the viscosity was 68 mPa·s, the surface tension of the gelling liquid was as low as 19.6 mN / m, and the oil-water interfacial tension was as low as 0.6892 mN / m. The contact angle of the hydrophilic surface could be changed from 58.4℃ to 92.5℃.

[0051] Example 2: As an optimization of the above example, the polymerizable monomer containing amphiphilic groups is one or more of long-chain alkyl sulfonic acid or sulfonate, and N-alkyl-substituted acrylamide, and the structural formula of the polymerizable monomer containing amphiphilic groups is:

[0052]

[0053] Wherein, R1 is an amide group substituted with N-long-chain alkyl and short-chain alkyl sulfonic acid or sulfonate, and R2 is an amide group monosubstituted or disubstituted with N-long-chain alkyl.

[0054] Example 3: As an optimization of the above examples, the R1 structure is as follows:

[0055]

[0056] Where n is an integer from 11 to 19.

[0057] Example 4: As an optimization of the above examples, the R2 structure is as follows:

[0058]

[0059] Where n is an integer from 11 to 19.

[0060] Example 5: As an optimization of the above examples, the structural formula of the fluorinated unsaturated monomer containing sulfonic acid groups is as follows:

[0061]

[0062] One of them, where m is an integer from 0 to 1 and n is an integer from 4 to 9.

[0063] Example 6: As an optimization of the above examples, a waterproof, high-temperature resistant, and high-salt fracturing thickener was obtained according to the following method:

[0064] S1, dissolve the required amounts of acrylamide hydrophilic monomer, sodium acrylate hydrophilic monomer, and polymerizable monomer containing amphiphilic groups in water in sequence and mix and stir evenly to obtain a mixed solution A with a total monomer mass concentration of 18% to 28%.

[0065] S2, dissolve the required amount of fluorine-substituted unsaturated monomer containing sulfonic acid groups in water to obtain an aqueous solution B with a mass concentration of 2%;

[0066] S3, dissolve the required amount of low-temperature composite initiator in water until homogeneous to obtain an aqueous solution C with a mass concentration of 2.0%;

[0067] S4. After adjusting the pH of mixed solution A to 9 to 10 with a pH adjuster, mixed solution A and aqueous solution B are refrigerated for 25 min and then the temperature is lowered to -5℃. Then, aqueous solution B and aqueous solution C are added to mixed solution A at a rate of 0.2 mL / min. After initiating the polymerization reaction for 3.5 h to 4.5 h, a colloidal product is obtained.

[0068] S5, after chopping, drying, pulverizing and sieving the colloidal product, a waterproof, high-temperature resistant and high-salt-resistant thickener is obtained.

[0069] Example 7: As an optimization of the above example, in step S4, the pH adjuster is one or more of sodium bicarbonate, sodium hydroxide, potassium hydroxide, citric acid, and glacial acetic acid, and the polymerization reaction temperature is -5°C to 25°C.

[0070] Example 8: As an optimization of the above example, in step S4, the low-temperature composite initiator is a mixture of sodium bisulfite, sodium persulfate and inorganic compound oxidant in a volume ratio of 1:1.2:0.12, wherein the volume ratio of the low-temperature composite initiator to the mixed solution A is 1:300, and the inorganic compound oxidant is one or more of cerium ammonium sulfate and cerium ammonium nitrate.

[0071] Example 9: As an optimization of the above example, the molecular weight of the waterproof, high temperature resistant and high salt resistant fracturing thickener ranges from 9.6 million Daltons to 16 million Daltons, and the size of the waterproof, high temperature resistant and high salt resistant fracturing thickener is ≥80 mesh.

[0072] Example 10: The preparation method of this waterproof, high-temperature resistant, and high-salt fracturing thickener is characterized by the following method:

[0073] S1, dissolve the required amounts of acrylamide hydrophilic monomer, sodium acrylate hydrophilic monomer, and polymerizable monomer containing amphiphilic groups in water in sequence and mix and stir evenly to obtain a mixed solution A with a total monomer mass concentration of 18% to 28%.

[0074] S2, dissolve the required amount of fluorine-substituted unsaturated monomer containing sulfonic acid groups in water to obtain an aqueous solution B with a mass concentration of 2%;

[0075] S3, dissolve the required amount of low-temperature composite initiator in water until homogeneous to obtain an aqueous solution C with a mass concentration of 2.0%;

[0076] S4. After adjusting the pH of mixed solution A to 9 to 10 with a pH adjuster, mixed solution A and aqueous solution B are refrigerated for 25 min and then the temperature is lowered to -5℃. Then, aqueous solution B and aqueous solution C are added to mixed solution A at a rate of 0.2 mL / min. After initiating the polymerization reaction for 3.5 h to 4.5 h, a colloidal product is obtained.

[0077] S5, after chopping, drying, pulverizing and sieving the colloidal product, a waterproof, high-temperature resistant and high-salt-resistant thickener is obtained.

[0078] Example 11: This waterproof, high-temperature resistant, and high-salt-resistant fracturing thickener was obtained according to the following method:

[0079] S1, Acrylamide, sodium acrylate, and sodium 2-acrylamido-2-methyltetradecyl sulfonate are mixed in a mass ratio of 1:0.15:0.02 and then diluted with water in a 1000mL beaker to prepare a mixed solution A with a total monomer mass concentration of 26%.

[0080] S2, Prepare an aqueous solution B with a mass concentration of 2% by mixing sodium 7-acryloylamino-5-perfluorooxy-1,3-naphthalenedisulfonate and acrylamide at a mass ratio of 0.003:1;

[0081] S3, Dissolve 2.0 mL of low-temperature composite initiator in water until homogeneous to obtain an aqueous solution C with a mass concentration of 2.0%;

[0082] S4. After adjusting the pH of mixed solution A to 9 with sodium bicarbonate, mixed solution A and aqueous solution B were refrigerated for 25 min and then the temperature was lowered to -5℃. Aqueous solutions B and C were then added to mixed solution A at a rate of 0.2 mL / min. An electronic thermometer was inserted to monitor the reaction temperature. The polymerization reaction was initiated for 4 h. When the temperature reached its maximum and then dropped, the change was no more than 1℃. The reaction was then completed, and a colloidal product was obtained.

[0083] S5, after the colloidal product is chopped into small particles of about 5mm, dried at 95℃, pulverized, and sieved through an 80-mesh sieve, a waterproof, high-temperature resistant, and high-salt-resistant thickener with a mesh size ≥80 is obtained, denoted as FNK-1.

[0084] The viscosity-average molecular weight of the waterproof, high-temperature resistant, and high-salt-resistant thickener (FNK-1) obtained in Example 11 was determined to be 16 million Daltons using an Ubbelohde viscometer (0.55 mm capillary inner diameter) according to the standard GB / T 12005.10-1992 Determination of Molecular Weight of Polyacrylamide.

[0085] Example 12:

[0086] The method described in Example 11 was followed, except that the mass ratio of acrylamide, sodium acrylate, sodium 2-acrylamido-2-methyltetradecyl sulfonate, and sodium 7-acrylamido-5-perfluorooxy-1,3-naphthalenedisulfonate was 1:0.15:0.02:0.008, resulting in a waterproof, high-temperature resistant, and high-salt fracturing-resistant thickener with a mesh size ≥80, denoted as FNK-2. The viscosity-average molecular weight of the waterproof, high-temperature resistant, and high-salt fracturing-resistant thickener (FNK-2) obtained in Example 12 was determined to be 15.23 million Daltons using an Ubbelohde viscometer (0.55 mm capillary inner diameter) according to the standard GB / T 12005.10-1992 "Determination of Molecular Weight of Polyacrylamide".

[0087] Example 13:

[0088] The method of Example 11 was followed, except that the mass ratio of acrylamide, sodium acrylate, sodium 2-acrylamido-2-methyltetradecyl sulfonate, and sodium 7-acrylamido-5-perfluorooxy-1,3-naphthalenedisulfonate was 1:0.15:0.08:0.003, resulting in a waterproof, high-temperature resistant, and high-salt fracturing-resistant thickener with a mesh size ≥80, denoted as FNK-3. The viscosity-average molecular weight of the waterproof, high-temperature resistant, and high-salt fracturing-resistant thickener (FNK-3) obtained in Example 13 was determined to be 13.21 million Daltons using an Ubbelohde viscometer (0.55 mm capillary inner diameter) according to the standard GB / T 12005.10-1992 "Determination of Molecular Weight of Polyacrylamide".

[0089] Example 14

[0090] The method of Example 11 was followed, except that the mass ratio of acrylamide, sodium acrylate, sodium 2-acrylamido-2-methyltetradecyl sulfonate, and sodium 7-acrylamido-5-perfluorooxy-1,3-naphthalenedisulfonate was 1:0.15:0.08:0.008, resulting in a waterproof, high-temperature resistant, and high-salt fracturing-resistant thickener with a mesh size ≥80, designated FNK-4. The viscosity-average molecular weight of the waterproof, high-temperature resistant, and high-salt fracturing-resistant thickener (FNK-4) obtained in Example 14 was determined to be 12.47 million Daltons using an Ubbelohde viscometer (0.55 mm capillary inner diameter) according to the standard GB / T 12005.10-1992 "Determination of Molecular Weight of Polyacrylamide".

[0091] Example 15

[0092] The method of Example 11 was followed, except that the mass ratio of acrylamide, sodium acrylate, sodium 2-acrylamido-2-methyltetradecyl sulfonate, and sodium 7-acrylamido-5-perfluorooxy-1,3-naphthalenedisulfonate was 1:0.3:0.02:0.003, resulting in a waterproof, high-temperature resistant, and high-salt fracturing-resistant thickener with a mesh size ≥80, denoted as FNK-5. The viscosity-average molecular weight of the waterproof, high-temperature resistant, and high-salt fracturing-resistant thickener (FNK-5) obtained in Example 15 was determined to be 14.28 million Daltons using an Ubbelohde viscometer (0.55 mm capillary inner diameter) according to the standard GB / T 12005.10-1992 "Determination of Molecular Weight of Polyacrylamide".

[0093] Example 16

[0094] The method of Example 11 was followed, except that the mass ratio of acrylamide, sodium acrylate, sodium 2-acrylamido-2-methyltetradecyl sulfonate, and sodium 7-acrylamido-5-perfluorooxy-1,3-naphthalenedisulfonate was 1:0.3:0.02:0.008, resulting in a waterproof, high-temperature resistant, and high-salt fracturing-resistant thickener with a mesh size ≥80, designated FNK-6. The viscosity-average molecular weight of the waterproof, high-temperature resistant, and high-salt fracturing-resistant thickener (FNK-6) obtained in Example 16 was determined to be 13.45 million Daltons using an Ubbelohde viscometer (0.55 mm capillary inner diameter) according to the standard GB / T 12005.10-1992 "Determination of Molecular Weight of Polyacrylamide".

[0095] Example 17

[0096] The method of Example 11 was followed, except that the mass ratio of acrylamide, sodium acrylate, sodium 2-acrylamido-2-methyltetradecyl sulfonate, and sodium 7-acrylamido-5-perfluorooxy-1,3-naphthalenedisulfonate was 1:0.3:0.08:0.003, resulting in a waterproof, high-temperature resistant, and high-salt fracturing-resistant thickener with a mesh size ≥80, designated FNK-7. The viscosity-average molecular weight of the waterproof, high-temperature resistant, and high-salt fracturing-resistant thickener (FNK-7) obtained in Example 17 was determined to be 11.25 million Daltons using an Ubbelohde viscometer (0.55 mm capillary inner diameter) according to the standard GB / T 12005.10-1992 "Determination of Molecular Weight of Polyacrylamide".

[0097] Example 18

[0098] The method of Example 11 was followed, except that the mass ratio of acrylamide, sodium acrylate, sodium 2-acrylamido-2-methyltetradecyl sulfonate, and sodium 7-acrylamido-5-perfluorooxy-1,3-naphthalenedisulfonate was 1:0.3:0.08:0.008, resulting in a waterproof, high-temperature resistant, and high-salt fracturing-resistant thickener with a mesh size ≥80, designated FNK-8. The viscosity-average molecular weight of the waterproof, high-temperature resistant, and high-salt fracturing-resistant thickener (FNK-8) obtained in Example 18 was determined to be 10.42 million Daltons using an Ubbelohde viscometer (0.55 mm capillary inner diameter) according to the standard GB / T 12005.10-1992 "Determination of Molecular Weight of Polyacrylamide".

[0099] Example 19

[0100] The procedure was carried out according to Example 11, except that sodium 2-acrylamido-2-methyltetradecyl sulfonate was replaced with N-dodecylacrylamide to obtain a waterproof, high-temperature resistant, and high-salt fracturing-resistant thickener with a mesh size ≥80, denoted as FNK-9. The viscosity-average molecular weight of the waterproof, high-temperature resistant, and high-salt fracturing-resistant thickener (FNK-9) obtained in Example 19 was determined to be 15.38 million Daltons using an Ubbelohde viscometer (0.55 mm capillary inner diameter) according to the standard GB / T 12005.10-1992 "Determination of Molecular Weight of Polyacrylamide".

[0101] Example 20

[0102] The procedure was carried out according to Example 18, except that sodium 2-acrylamido-2-methyltetradecyl sulfonate was replaced with N-dodecylacrylamide to obtain a waterproof, high-temperature resistant, and high-salt fracturing-resistant thickener with a mesh size ≥80, denoted as FNK-10. The viscosity-average molecular weight of the waterproof, high-temperature resistant, and high-salt fracturing-resistant thickener FNK-10 obtained in Example 20 was determined to be 9.6 million Daltons using an Ubbelohde viscometer (0.55 mm capillary inner diameter) according to the standard GB / T 12005.10-1992 "Determination of Molecular Weight of Polyacrylamide".

[0103] Example 21

[0104] The procedure was carried out according to Example 11, except that sodium 7-acrylamido-5-perfluorooxy-1,3-naphthalenedisulfonate was replaced with sodium 7-vinyl-5-perfluorooxy-1,3-naphthalenedisulfonate, resulting in a waterproof, high-temperature resistant, and high-salt fracturing-resistant thickener with a mesh size ≥80, denoted as FNK-11. The viscosity-average molecular weight of the waterproof, high-temperature resistant, and high-salt fracturing-resistant thickener (FNK-11) obtained in Example 21 was determined to be 15.62 million Daltons using an Ubbelohde viscometer (0.55 mm capillary inner diameter) according to the standard GB / T 12005.10-1992 "Determination of Molecular Weight of Polyacrylamide".

[0105] Example 22

[0106] The procedure was carried out according to Example 18, except that sodium 7-acrylamido-5-perfluorooxy-1,3-naphthalenedisulfonate was replaced with sodium 7-vinyl-5-perfluorooxy-1,3-naphthalenedisulfonate, resulting in a waterproof, high-temperature resistant, and high-salt fracturing-resistant thickener with a mesh size ≥80, denoted as FNK-12. The viscosity-average molecular weight of the waterproof, high-temperature resistant, and high-salt fracturing-resistant thickener (FNK-12) obtained in Example 22 was determined to be 9.96 million Daltons using an Ubbelohde viscometer (0.55 mm capillary inner diameter) according to the standard GB / T12005.10-1992 "Determination of Molecular Weight of Polyacrylamide".

[0107] Comparative Example 1

[0108] The procedure was followed according to Example 11, except that sodium 7-acrylamido-5-perfluorooxy-1,3-naphthalenedisulfonate was not added, resulting in a salt fracturing thickener with a mesh size ≥ 80 mesh, denoted as DNK-1. The viscosity-average molecular weight of the salt fracturing thickener (DNK-1) obtained in Comparative Example 1 was determined to be 17.23 million Daltons using an Ubbelohde viscometer (0.55 mm capillary inner diameter) according to the standard GB / T 12005.10-1992 "Determination of Molecular Weight of Polyacrylamide".

[0109] Comparative Example 2

[0110] The procedure was carried out according to Example 18, except that sodium 7-acrylamido-5-perfluorooxy-1,3-naphthalenedisulfonate was not added, resulting in a salt fracturing thickener with a mesh size ≥80, denoted as DNK-2. The viscosity-average molecular weight of the salt fracturing thickener (DNK-2) obtained in Comparative Example 2 was determined to be 11.21 million Daltons using an Ubbelohde viscometer (0.55 mm capillary inner diameter) according to the standard GB / T 12005.10-1992 "Determination of Molecular Weight of Polyacrylamide".

[0111] The test methods for thickener performance are as follows:

[0112] (1) Tack time

[0113] Accurately weigh the calculated amount of thickener powder into a 500mL beaker pre-filled with an appropriate amount of brine (total mineralization 150000mg / L, of which calcium and magnesium ion content is 10000mg / L). Dissolve the thickener using a high-speed stirrer at room temperature and a speed of 400±50rad / min. When the thickener forms a string when picked up with a glass rod, record the corresponding time, which is the thickening time.

[0114] (2) Viscosity and viscosity release rate

[0115] Prepare salt water solutions with thickener concentrations of 0.6% and 1.2% according to the method in (1), and use a six-speed rotational viscometer at 100 r / min (170 s). -1 The viscosity values ​​were tested at different dissolution times, and the viscosity release rate was calculated using the following formula. When the viscosity was below 10 mPa·s, a capillary viscometer was used to test the kinematic viscosity of the product.

[0116]

[0117] In the formula, V R The viscosity before stabilization is in mPa·s; V F For the final stable viscosity, mPa·s; R V Viscosity release rate, %.

[0118] (3) Temperature resistance and shear resistance

[0119] Using the RS6000 advanced rheometer PZ38 coaxial cylindrical rotor system at 180℃ for 170s -1 The obtained thickener aqueous solution was subjected to a temperature resistance and shear resistance test. The viscosity change curve over time was recorded and the final stable viscosity value was recorded. The duration from heating to the end of the test was 2 hours.

[0120] (4) Debriding performance

[0121] 100g of thickener aqueous solution was weighed and placed into a metal sealed container, and 0.03% ammonium persulfate (APS) was added. After sealing and aging at 180℃ for different times, the container was taken out and tested according to the industry standard SY / T 5107-2016 "Performance Evaluation Method of Water-based Fracturing Fluid". The viscosity, surface tension, oil-water interfacial tension and residue content of the breaker fluid were tested at room temperature. The oil-water interfacial tension of the breaker fluid was tested with kerosene as the oil phase.

[0122] The tackification time and viscosity release rate at different concentrations of the waterproof, high-temperature resistant, and high-salt fracturing thickeners prepared in Examples 11 to 22 and Comparative Examples 1 to 2 were tested using the above method at a mineralization of 150,000 mg / L (calcium and magnesium ions contained in 10,000 mg / L). The results are shown in Table 1. Table 1 shows that the waterproof, high-temperature resistant, and high-salt fracturing thickeners (FNK-1, FNK-9, and FNK-11) obtained by introducing fluorinated unsaturated monomers containing sulfonic acid groups in Examples 11, 19, and 21, at mass concentrations of 0.6% and 1.2%, have stable viscosities at these concentrations that are at least 8 mPa·s and 17 mPa·s higher, respectively, than the salt-resistant fracturing thickener obtained in Comparative Example 1 (DNK-1, without the introduction of fluorinated unsaturated monomers containing sulfonic acid groups). The waterproof, high-temperature resistant, and high-salt fracturing thickeners (FNK-8, FNK-10, and FNK-12) obtained by introducing fluorine-substituted unsaturated monomers containing sulfonic acid groups in Examples 18, 20, and 22, have stable viscosities at mass concentrations of 0.6% and 1.2% respectively, which are at least 8 mPa·s and 17 mPa·s higher than the salt fracturing thickener obtained in Comparative Example 2 (DNK-2, without the introduction of fluorine-substituted unsaturated monomers containing sulfonic acid groups).

[0123] The temperature and shear resistance of the salt fracturing thickeners obtained in Examples 11, 18, 19, 20, 21, 22 and Comparative Examples 1 to 2 were tested at 180°C with a mineralization of 150,000 mg / L (calcium and magnesium ions contained in 10,000 mg / L) using the above method. The results are shown in Table 2.

[0124] As shown in Table 2, the water-resistant, high-temperature resistant, and high-salt fracturing thickeners (FNK-1, FNK-9, and FNK-11) obtained by introducing fluorine-substituted unsaturated monomers containing sulfonic acid groups in Examples 11, 19, and 21 have a temperature-resistant and shear-resistant stable viscosity at an addition of 1.2% of the water-resistant, high-temperature resistant, and high-salt fracturing thickener, which is at least 14 mPa·s higher than the salt-resistant fracturing thickener (DNK-1, without the introduction of fluorine-substituted unsaturated monomers containing sulfonic acid groups) obtained in Comparative Example 1.

[0125] The waterproof, high-temperature resistant, and high-salt fracturing resistant thickeners (FNK-8, FNK-10, and FNK-12) obtained by introducing fluorine-substituted unsaturated monomers containing sulfonic acid groups in Examples 18, 20, and 22, have a temperature and shear stability viscosity at an addition of 1.2% of the waterproof, high-temperature resistant, and high-salt fracturing resistant thickener, which is at least 10 mPa·s higher than that of the salt fracturing resistant thickener obtained in Comparative Example 2 (DNK-2, without the introduction of fluorine-substituted unsaturated monomers containing sulfonic acid groups).

[0126] The above method was used to test the gel breaking performance of the waterproof, high-temperature resistant, and high-salt fracturing thickeners obtained in Examples 11, 18, 19, 20, 21, and 22, and the salt fracturing thickeners obtained in Comparative Examples 1 and 2, at a mineralization of 150,000 mg / L (calcium and magnesium ions containing 10,000 mg / L) and 180℃. The results are shown in Table 3. As can be seen from Table 3, the waterproof, high-temperature resistant, and high-salt fracturing thickeners (FNK-1, FNK-8, FNK-9, FNK-...) obtained by introducing fluorinated unsaturated monomers containing sulfonic acid groups in Examples 11, 18, 19, 20, 21, and 22... 10. FNK-11 and FNK-12, with a 1.2% mass concentration of waterproof, high-temperature resistant, and high-salt fracturing thickener, have a breaking viscosity and residue content comparable to the salt fracturing thickeners (DNK-1 and DNK-2, without the introduction of fluorine-substituted unsaturated monomers containing sulfonic acid groups) obtained in Comparative Examples 1 and 2; while the surface tension and oil-water interfacial tension of the breaking liquid are significantly lower than those in Comparative Examples 1 and 2, and the contact angle is significantly higher than that in Comparative Examples 1 and 2. The lowest surface tension of the breaking liquid can reach 19.24 mN / m, and the lowest oil-water interfacial tension can reach 0.6892 mN / m, which can change the contact angle of the hydrophilic surface from 58.4°C to 92.5°C.

[0127] The above data results indicate that by introducing fluorine-substituted unsaturated monomers containing sulfonic acid groups into the fracturing thickener, the waterproofing performance and high-temperature and high-salt resistance of the fracturing thickener of this invention are significantly improved.

[0128] In summary, by simultaneously introducing a polymerizable monomer containing amphiphilic groups and a fluorinated unsaturated monomer containing sulfonic acid groups into the fracturing thickener, this invention not only significantly improves the high temperature and high salt resistance of the thickener before gel breaking, but also features good waterproofing and locking properties, low dosage, and sufficient temperature and shear resistance.

[0129] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

[0130] Table 1

[0131]

[0132] Table 2

[0133] project Viscosity (mPa·s) project Viscosity (mPa·s) Example 11 57 Example 18 68 Example 19 48 Example 20 55 Example 21 52 Example 22 59 Comparative Example 1 34 Comparative Example 2 45

[0134] Table 3

[0135]

Claims

1. A waterproof, high-temperature resistant, and high-salt-resistant thickener for fracturing, characterized in that... The raw materials include acrylamide hydrophilic monomer, sodium acrylate hydrophilic monomer, polymerizable monomer containing amphiphilic groups, and fluorinated unsaturated monomer containing sulfonic acid groups. The mass ratio of acrylamide hydrophilic monomer, sodium acrylate hydrophilic monomer, polymerizable monomer containing amphiphilic groups, and fluorinated unsaturated monomer containing sulfonic acid groups is 1:0.15 to 0.3:0.02 to 0.08:0.003 to 0.

008.

2. The waterproof, high-temperature resistant, and high-salt-resistant thickener according to claim 1, characterized in that... The polymerizable monomer containing amphiphilic groups is one or more of long-chain alkyl sulfonic acids or sulfonates, or N-alkyl-substituted acrylamides, and the structural formula of the polymerizable monomer containing amphiphilic groups is: Wherein, R1 is an amide group substituted with N-long-chain alkyl and short-chain alkyl sulfonic acid or sulfonate, and R2 is an amide group monosubstituted or disubstituted with N-long-chain alkyl.

3. The waterproof, high-temperature resistant, and high-salt-resistant thickener according to claim 2, characterized in that... The R1 structure is: Where n is an integer from 11 to 19.

4. The waterproof, high-temperature resistant, and high-salt-resistant thickener according to claim 2 or 3, characterized in that... The R2 structure is: Where n is an integer from 11 to 19.

5. The waterproof, high-temperature resistant, and high-salt-resistant thickener according to any one of claims 1 to 4, characterized in that... The structural formula of the fluorinated unsaturated monomer containing a sulfonic acid group is: One of them, where m is an integer from 0 to 1 and n is an integer from 4 to 9.

6. The waterproof, high-temperature resistant, and high-salt-resistant thickener according to claim 5, characterized in that... It is obtained using the following method: S1, dissolve the required amounts of acrylamide hydrophilic monomer, sodium acrylate hydrophilic monomer, and polymerizable monomer containing amphiphilic groups in water in sequence and mix and stir evenly to obtain a mixed solution A with a total monomer mass concentration of 18% to 28%. S2, dissolve the required amount of fluorine-substituted unsaturated monomer containing sulfonic acid groups in water to obtain an aqueous solution B with a mass concentration of 2%; S3, dissolve the required amount of low-temperature composite initiator in water until homogeneous to obtain an aqueous solution C with a mass concentration of 2.0%; S4. After adjusting the pH of mixed solution A to 9 to 10 with a pH adjuster, mixed solution A and aqueous solution B are refrigerated for 25 min and then the temperature is lowered to -5℃. Then, aqueous solution B and aqueous solution C are added to mixed solution A at a rate of 0.2 mL / min. After initiating the polymerization reaction for 3.5 h to 4.5 h, a colloidal product is obtained. S5, after chopping, drying, pulverizing and sieving the colloidal product, a waterproof, high-temperature resistant and high-salt-resistant thickener is obtained.

7. The waterproof, high-temperature resistant, and high-salt-resistant fracturing thickener according to claim 6, characterized in that... In step S4, the pH adjuster is one or more of sodium bicarbonate, sodium hydroxide, potassium hydroxide, citric acid, and glacial acetic acid, and the polymerization reaction temperature is -5℃ to 25℃.

8. The waterproof, high-temperature resistant, and high-salt-resistant thickener according to claim 6 or 7, characterized in that... In step S4, the low-temperature composite initiator is a mixture of sodium bisulfite, sodium persulfate and inorganic compound oxidant in a volume ratio of 1:1.2:0.12, wherein the volume ratio of the low-temperature composite initiator to mixed solution A is 1:300, and the inorganic compound oxidant is one or more of cerium ammonium sulfate and cerium ammonium nitrate.

9. The waterproof, high-temperature resistant, and high-salt-resistant thickener according to claim 6, 7, or 8, characterized in that... The molecular weight range of the waterproof, high-temperature resistant, and high-salt-resistant fracturing thickener is 9.6 million to 16 million Daltons, and the size of the waterproof, high-temperature resistant, and high-salt-resistant fracturing thickener is ≥80 mesh.

10. A method for preparing a waterproof, high-temperature resistant, and high-salt-resistant fracturing thickener according to claims 1 to 5, 7, 8, or 9, characterized in that... Perform the following steps: S1, dissolve the required amounts of acrylamide hydrophilic monomer, sodium acrylate hydrophilic monomer, and polymerizable monomer containing amphiphilic groups in water in sequence and mix and stir evenly to obtain a mixed solution A with a total monomer mass concentration of 18% to 28%. S2, dissolve the required amount of fluorine-substituted unsaturated monomer containing sulfonic acid groups in water to obtain an aqueous solution B with a mass concentration of 2%; S3, dissolve the required amount of low-temperature composite initiator in water until homogeneous to obtain an aqueous solution C with a mass concentration of 2.0%; S4. After adjusting the pH of mixed solution A to 9 to 10 with a pH adjuster, mixed solution A and aqueous solution B are refrigerated for 25 min and then the temperature is lowered to -5℃. Then, aqueous solution B and aqueous solution C are added to mixed solution A at a rate of 0.2 mL / min. After initiating the polymerization reaction for 3.5 h to 4.5 h, a colloidal product is obtained. S5, after chopping, drying, pulverizing and sieving the colloidal product, a waterproof, high-temperature resistant and high-salt-resistant thickener is obtained.

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