Compounds, polymers with high tack function and methods of making and using the same

Abstract

This invention relates to the field of petroleum extraction technology, and discloses a compound, a polymer with high viscosity, its preparation method, and its applications. The compound of this invention has the structure shown in formula (8). The polymer of this invention exhibits high viscoelasticity and high aqueous viscosity at 20-85℃ and a salinity of 500-50000 mg / L, effectively improving the mobility ratio, expanding the swept volume, and adjusting the profile. It can be used for polymer flooding to enhance oil recovery in conventional reservoirs, high-temperature and high-salinity reservoirs, and ordinary heavy oil reservoirs.

Description

Technical Field

[0001] This invention relates to the field of petroleum extraction technology, specifically to a compound, a polymer with high viscosity, its preparation method, and its application. Background Technology

[0002] Chemical flooding is a major technique for enhancing oil recovery in my country's medium-to-high permeability, high water-cut, heavy oil, and complex fault-block reservoirs. It includes conventional tertiary oil recovery technologies such as surfactants, polymers, and ternary / binary composite flooding. The main principle of polymer flooding is to increase the viscosity of the aqueous phase and improve the oil-water mobility ratio, primarily increasing the sweep efficiency of medium-to-low permeability layers. Simultaneously, the shear stress and viscoelasticity of the polymer solution can displace isolated or film-like residual oil, reducing blind residual oil.

[0003] However, with the full utilization of high-quality resources in Class I and II reservoirs, complex and demanding reservoir conditions have presented new challenges to the development and innovation of chemical flooding technology. These challenges include the high-temperature and high-salinity environment of Class III and above reservoirs; high-permeability and high-water-cut reservoir environments after chemical flooding; and heavy oil reservoir environments with low recovery rates. Existing research indicates that conventional chemical flooding agents have limited viscosity-enhancing effects in these environments. Therefore, the reduction in the heavy oil / water mobility ratio and the expansion of the swept volume are small, failing to meet the needs of oilfield development.

[0004] Therefore, developing a highly efficient aqueous phase viscosity-enhancing polymer is of great significance for improving the recovery rate of polymer flooding. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems existing in the prior art and provide a compound and its preparation method, a polymer with high viscosity and its preparation method and application. This compound simultaneously possesses benzene ring groups and long-chain alkane groups, exhibiting rigidity and steric hindrance, which can suppress molecular chain compression under high temperature and high mineralization conditions.

[0006] This compound, when copolymerized with acrylamide and N-alkyl-substituted acrylamide, can achieve temperature- and salt-induced viscosity enhancement within a certain temperature and salinity range. This is because the N-alkyl-substituted nonionic groups can form nonpolar aggregation regions with the alkane nonionic groups in the compound under certain temperature and salinity conditions, increasing the intermolecular forces. Simultaneously, the rigid structure (benzene ring, five-membered ring group) and steric hindrance of the compound effectively resist the compression of polymer chains under high temperature and high salinity conditions, improving temperature and salt resistance. The polymer of this invention exhibits high viscoelasticity and high aqueous viscosity at 20-85℃ and a salinity of 500-50000 mg / L, effectively improving the mobility ratio, expanding the swept volume, and adjusting the profile. It can be used for polymer flooding to enhance oil recovery in conventional reservoirs, high-temperature and high-salinity reservoirs, and ordinary heavy oil reservoirs.

[0007] To achieve the above objectives, a first aspect of the present invention provides a compound having the structure shown in formula (8):

[0008]

[0009] Where 4≤n≤19 (e.g., 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19).

[0010] A second aspect of the present invention provides a method for preparing the compound as described above, the method comprising the following steps:

[0011] (1) Under alkylation reaction conditions, ethylene glycol is successively reacted with sodium hydride and bromoalkane in a first contact and a second contact to obtain a structure such as HO-(CH2)2-O-(CH2). n -CH3 monosubstituted alcohol ethers;

[0012] (2) Under chlorination reaction conditions, the monosubstituted alcohol ether obtained in step (1) is subjected to a third contact with thionyl chloride to obtain a structure such as Cl-(CH2)2-O-(CH2). n -CH3 chloro alcohol ethers;

[0013] (3) Under amidation reaction conditions, 5-hydroxyindole is reacted with acryloyl chloride in a fourth contact to obtain amidated hydroxyindole;

[0014] (4) Under etherification reaction conditions, the chlorool ether obtained in step (2) is brought into a fifth contact with the amidated hydroxyindole obtained in step (3);

[0015] Preferably, the bromoalkane is selected from at least one of 1-bromobutane, 1-bromopentane, 1-bromohexane, 1-bromoheptane, 1-bromooctane, 1-bromononane, 1-bromodecane, 1-bromoundecane, 1-bromododecane, 1-bromotridecane, 1-bromotetradecane, 1-bromopentadecane, bromohexadecane, 1-bromoheptadecane, 1-bromooctadecane, and bromoeicosane.

[0016] The third aspect of the present invention provides a polymer containing structural unit P, structural unit C and structural unit D, characterized in that the structural unit P is structural unit A having the structure shown in formula (1) and / or structural unit B having the structure shown in formula (2), the structural unit C is structural unit having the structure shown in formula (3), and the structural unit D is structural unit having the structure shown in formula (4).

[0017]

[0018] In this configuration, R1 and R2 are each independently H or methyl, M1 is H or an alkali metal, and R3 is C6-C.18 Alkyl groups; 4 ≤ n ≤ 19 (e.g., 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19).

[0019] A fourth aspect of the present invention provides a method for preparing a polymer, the method comprising: under solution polymerization conditions, in the presence of an initiator, causing monomers to undergo a polymerization reaction to obtain a copolymer colloid; hydrolyzing the copolymer colloid or not hydrolyzing it; wherein the monomers include monomer P', monomer C' as shown in formula (7), monomer D' as shown in formula (8), and monomer P' being monomer A' as shown in formula (5) and / or monomer B' as shown in formula (6);

[0020]

[0021] In this configuration, R1 and R2 are each independently H or methyl, M1 is H or an alkali metal, and R3 is C6-C. 18 Alkyl groups, 4≤n≤19 (e.g., 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19).

[0022] A fifth aspect of the present invention provides a polymer prepared by the preparation method described above.

[0023] The sixth aspect of the present invention provides the use of the polymer as described above in oil displacement.

[0024] The beneficial effects obtained by the present invention through the above technical solution are as follows:

[0025] (1) The compound described in this invention contains long-chain alkane nonionic groups and rigid groups (benzene ring and five-membered ring), which have great rigidity and steric hindrance effect, and can suppress molecular chain compression under high temperature and high mineralization.

[0026] (2) The compounds of the present invention are subjected to free radical copolymerization with acrylamide and / or N-alkyl-substituted acrylamide to obtain polymers exhibiting temperature-induced and salt-induced viscosity-increasing properties. This is because, within a certain temperature and salinity range, the alkane groups in the compounds of the present invention can form nonpolar aggregate regions with the nonionic groups in the N-alkyl-substituted acrylamides, increasing the intermolecular forces and increasing the bulk viscosity. Simultaneously, as the temperature increases, more nonpolar aggregate regions are formed, exhibiting temperature-induced viscosity-increasing properties. Furthermore, as salinity increases, the hydration layer around the polymer molecules is disrupted, increasing the probability of nonpolar group aggregation and exhibiting salt-induced viscosity-increasing properties. At the same time, the rigid groups and steric hindrance effects in the compounds effectively resist the compression of polymer chains under high temperature and high salinity conditions, improving temperature and salt resistance while maintaining high viscosity at high temperatures and high salinity.

[0027] (3) The polymer of the present invention has high viscoelasticity and high viscosity in the aqueous phase under the conditions of 20-85℃ and 500-50000mg / L of salinity, especially under the conditions of 30-80℃ and 1000-20000mg / L of salinity. It has good viscosity-enhancing ability for the aqueous phase, can effectively improve the oil-water mobility ratio, expand the swept volume, and improve the profile. It can be used as an oil displacement agent and profile improver for polymer flooding to enhance the recovery rate in conventional oil reservoirs, high-temperature and high-salinity oil reservoirs and ordinary heavy oil reservoirs. Detailed Implementation

[0028] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0029] The first aspect of the present invention provides a compound having the structure shown in formula (8):

[0030]

[0031] Where 4≤n≤19 (e.g., 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19).

[0032] In this invention, n is an integer.

[0033] A second aspect of the present invention provides a method for preparing the compound as described above, the method comprising the following steps:

[0034] (1) Under alkylation reaction conditions, ethylene glycol is successively reacted with sodium hydride and bromoalkane in a first contact and a second contact to obtain a structure such as HO-(CH2)2-O-(CH2). n -CH3 monosubstituted alcohol ethers;

[0035] (2) Under chlorination reaction conditions, the monosubstituted alcohol ether obtained in step (1) is subjected to a third contact with thionyl chloride to obtain a structure such as Cl-(CH2)2-O-(CH2). n -CH3 chloro alcohol ethers;

[0036] (3) Under amidation reaction conditions, 5-hydroxyindole is reacted with acryloyl chloride in a fourth contact to obtain amidated hydroxyindole;

[0037] (4) Under etherification reaction conditions, the chlorool ether obtained in step (2) is brought into a fifth contact with the amidated hydroxyindole obtained in step (3);

[0038] Preferably, the bromoalkane is selected from at least one of 1-bromobutane, 1-bromopentane, 1-bromohexane, 1-bromoheptane, 1-bromooctane, 1-bromononane, 1-bromodecane, 1-bromoundecane, 1-bromododecane, 1-bromotridecane, 1-bromotetradecane, 1-bromopentadecane, bromohexadecane, 1-bromoheptadecane, 1-bromooctadecane, and bromoeicosane.

[0039] In this invention, 4≤n≤19 (e.g., 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19).

[0040] In this invention, n is an integer.

[0041] In this invention, there is no particular limitation on the amount of each raw material used in the preparation process of the compound.

[0042] In some embodiments of the present invention, the amount of sodium hydride used is 1-1.5 mol relative to 1 mol of ethylene glycol.

[0043] In some embodiments of the present invention, the amount of the brominated alkane is 0.8-1.5 mol relative to 1 mol of ethylene glycol, preferably 0.9-1.3 mol.

[0044] In some embodiments of the present invention, the amount of thionyl chloride used is 0.3-1.5 mol relative to 1 mol of ethylene glycol, preferably 0.4-1.2 mol.

[0045] In some embodiments of the present invention, the amount of acryloyl chloride used is 0.5-1.5 mol relative to 1 mol of 5-hydroxyindole, preferably 0.8-1.2 mol.

[0046] In some embodiments of the present invention, the amount of amidated hydroxyindole is 0.6-1.2 mol relative to 1 mol of the chloroethanol ether.

[0047] In some embodiments of the present invention, the bromoalkane is selected from at least one of 1-bromobutane, 1-bromopentane, 1-bromohexane, 1-bromoheptane, 1-bromooctane, 1-bromononane, 1-bromodecane, 1-bromoundecane, 1-bromododecane, 1-bromotridecane, 1-bromotetradecane, 1-bromopentadecanane, bromohexadecane, 1-bromoheptadecane, 1-bromooctadecane, and bromoeicosane.

[0048] In some embodiments of the present invention, in step (1), the alkylation reaction conditions include: a reaction temperature of 0-35°C, preferably 15-30°C.

[0049] In some embodiments of the present invention, the first contact time is 20-60 min, preferably 25-45 min.

[0050] In some embodiments of the present invention, the first contact is carried out in an organic solvent, preferably, the organic solvent is selected from at least one of tetrahydrofuran and ethylene glycol dimethyl ether.

[0051] In some embodiments of the present invention, step (1) includes: dissolving ethylene glycol in an organic solvent, adding sodium hydride thereto, and conducting a first contact under alkylation reaction conditions. Preferably, in order to prevent the release of hydrogen gas during the first contact reaction from being too violent, the sodium hydride may be added in 3-5 portions.

[0052] In some embodiments of the present invention, in step (1), the second contact time is 1.5-6 hours, preferably 2-4 hours.

[0053] In some embodiments of the present invention, step (1) includes: adding a brominated alkane to the reaction system after the first contact. The rate at which the brominated alkane is added can be selected within a wide range, as long as the reaction process in the second contact is prevented from being too vigorous. Preferably, the rate at which the brominated alkane is added is 10-20 mmol / min relative to 100 mmol of ethylene glycol.

[0054] In some embodiments of the present invention, step (1) further includes purification after the second contact. The purification method is not particularly limited; for example, extraction evaporation, recrystallization, column chromatography, etc., can be used for purification. According to a specific embodiment of the present invention, the purification includes: quenching the reaction system with water after the second contact, then filtering to remove the solid, removing unreacted brominated alkanes by vacuum distillation, and cooling to room temperature (20-25°C).

[0055] In some embodiments of the present invention, in step (2), the chlorination reaction conditions include: a reaction temperature of 60-90°C, preferably 65-75°C.

[0056] In some embodiments of the present invention, in step (2), the third contact time is 8-12 hours, preferably 10-11 hours.

[0057] In some embodiments of the present invention, step (2) includes adding thionyl chloride to the reaction system obtained in step (1). The rate of addition of the thionyl chloride can be selected within a wide range, as long as the reaction process of the third contact is not too vigorous. Preferably, the rate of addition of the thionyl chloride is 50-200 mmol / min relative to 1 mol of the monosubstituted alcohol ether.

[0058] In some embodiments of the present invention, in order to improve the reaction yield and neutralize the hydrogen chloride generated during the third contact (i.e., the chlorination reaction of thionyl chloride with a monosubstituted alcohol ether), the third contact is carried out in the presence of pyridine. Preferably, step (2) includes: sequentially adding pyridine and thionyl chloride to the reaction system obtained in step (1), and then carrying out the third contact under chlorination reaction conditions to obtain a chlorinated alcohol ether. Preferably, the amount of pyridine used is 0.8-1.6 mol relative to 1 mol of the monosubstituted alcohol ether.

[0059] In some embodiments of the present invention, step (2) further includes purification after the third contact. The purification method is not particularly limited; for example, extraction by rotary evaporation, recrystallization, column chromatography, etc., can be used for purification. According to a specific embodiment of the present invention, the purification includes: cooling the reaction system after the third contact to room temperature (20-25°C), allowing it to stand and separate into layers, taking the upper organic layer, adjusting the pH to 8-8.3, washing with water 5-6 times, and drying by rotary evaporation.

[0060] In some embodiments of the present invention, in step (3), the amidation reaction conditions include: a reaction temperature of 0-35°C, preferably 10-25°C.

[0061] In some embodiments of the present invention, in step (3), the fourth contact time is 6-15 hours, preferably 8-10 hours.

[0062] In some embodiments of the present invention, the fourth contact is carried out under stirring, and the stirring rate is selected using conventional techniques in the art. Those skilled in the art can select the rate according to the actual situation, and it will not be elaborated here.

[0063] In some embodiments of the present invention, the fourth contact is carried out in an organic solvent, preferably, the organic solvent is selected from at least one of tetrahydrofuran and ethylene glycol dimethyl ether.

[0064] In some embodiments of the present invention, step (3) includes: dissolving 5-hydroxyindole in an organic solvent, and then adding acryloyl chloride. The rate of addition of the acryloyl chloride can be selected within a wide range, as long as the reaction process of the fourth contact is prevented from being too vigorous. Preferably, the rate of addition of the acryloyl chloride is 80-150 mmol / min relative to 1 mol of 5-hydroxyindole. Preferably, the temperature at which the acryloyl chloride is added is 0-8°C.

[0065] In some embodiments of the present invention, in order to adjust the pH to alkaline, step (3) further includes: mixing 5-hydroxyindole and triethylamine at 10-35°C for 5-30 min before the fourth contact.

[0066] In some embodiments of the present invention, step (3) includes: mixing 5-hydroxyindole with triethylamine at 10-35°C for 5-30 min, then adding acryloyl chloride at 0-8°C, and then performing a fourth contact under amidation reaction conditions to obtain amidated hydroxyindole.

[0067] In some embodiments of the present invention, step (3) further includes purification after the fourth contact. The purification method is not particularly limited; for example, extraction, rotary evaporation, recrystallization, column chromatography, etc., can be used for purification. According to a specific embodiment of the present invention, the purification includes: quenching the reaction system with water after the fourth contact, then extracting with diethyl ether (preferably 75 mL × 3) to obtain an organic phase, drying the organic phase with Na₂SO₄, rotary evaporation, and recrystallization. Preferably, the recrystallization solvent is a mixture of dichloromethane and petroleum ether at a volume ratio of 4:1.

[0068] In some embodiments of the present invention, in step (4), the etherification reaction conditions include a reaction temperature of 60-90°C, preferably 75-85°C.

[0069] In some embodiments of the present invention, in step (4), the fifth contact time is 3-10 hours, preferably 4-9 hours.

[0070] In some embodiments of the present invention, the fifth contact is carried out in an organic solvent, preferably, the organic solvent is selected from at least one of tetrahydrofuran and ethylene glycol dimethyl ether.

[0071] In some embodiments of the present invention, in order to promote the etherification reaction and neutralize the hydrogen halide produced in the reaction, step (4) includes: dissolving the amidated hydroxyindole obtained in step (3) in an organic solvent, adding potassium carbonate, and then adding chloroethanol ether for a fifth contact. The amount of potassium carbonate used is 1.0-1.5 mol relative to 1 mol of amidated hydroxyindole.

[0072] In some embodiments of the present invention, step (4) further includes purification after the fifth contact. The purification method is not particularly limited; for example, extraction, rotary evaporation, recrystallization, or column chromatography can be used. According to a specific embodiment of the present invention, the purification includes: cooling the reaction system after the fourth contact to room temperature (20-25°C), then quenching the reaction system with water, adjusting the pH to 3 with dilute hydrochloric acid solution, extracting the system with diethyl ether to obtain an organic phase, washing the organic phase 3-5 times with saturated sodium chloride, drying the organic phase with Na2SO4, and recrystallizing after rotary evaporation. Preferably, the recrystallization solvent is a mixture of dichloromethane and petroleum ether at a volume ratio of 4:1.

[0073] In some embodiments of the present invention, the first contact, the second contact, the third contact, the fourth contact, and the fifth contact are carried out in an organic solvent. Preferably, the organic solvent is selected from at least one of tetrahydrofuran and ethylene glycol dimethyl ether.

[0074] According to a preferred embodiment of the present invention, the compound is prepared by the following method:

[0075] (1) Under alkylation reaction conditions, ethylene glycol is dissolved in an organic solvent, sodium hydride is added for the first contact, and then brominated alkanes are added for the second contact to obtain monosubstituted alcohol ethers;

[0076] (2) Pyridine and thionyl chloride were added sequentially to the monosubstituted alcohol ether obtained in step (1), and then a third contact was carried out under chlorination reaction conditions to obtain chlorinated alcohol ether, which was then purified.

[0077] (3) Dissolve hydroxyindole in an organic solvent, add triethylamine and mix at 10-35℃ for 5-30 min, then add acryloyl chloride dropwise in an ice-water bath at 0℃. After the dropwise addition is completed, carry out the fourth contact under amidation reaction conditions to obtain amidated hydroxyindole, and then purify the substance.

[0078] (4) The purified products of step (2) and step (3) are heated and refluxed at 60-90°C for 3-10 hours in the presence of potassium carbonate to obtain the compound.

[0079] The present invention does not particularly limit the method for purifying the reaction products in steps (2), (3), and (4). For example, extraction and recrystallization can be used independently for purification. In a preferred embodiment, the purification is carried out as follows: the above reaction products are quenched with water, then extracted with diethyl ether, and the organic phase obtained by extraction is dried with sodium sulfate. The dried product is then evaporated to dryness, and then recrystallized with n-hexane and / or dichloromethane.

[0080] The third aspect of the present invention provides a polymer containing structural unit P, structural unit C and structural unit D, characterized in that the structural unit P is structural unit A having the structure shown in formula (1) and / or structural unit B having the structure shown in formula (2), the structural unit C is structural unit having the structure shown in formula (3), and the structural unit D is structural unit having the structure shown in formula (4).

[0081]

[0082] In this configuration, R1 and R2 are each independently H or methyl, M1 is H or an alkali metal, and R3 is C6-C. 18 Alkyl groups (especially straight-chain alkyl groups) of C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18; 4 ≤ n ≤ 19 (e.g., 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19).

[0083] In this invention, n is an integer.

[0084] In some embodiments of the present invention, M1 is H, sodium, or potassium.

[0085] In some embodiments of the present invention, R1 is H, R2 is H, R3 is octyl, M1 is Na, and n is 15.

[0086] In some embodiments of the present invention, R1 is H, R2 is H, R3 is nonyl, M1 is Na, and n is 9.

[0087] In some embodiments of the present invention, R1 is H, R2 is H, R3 is dodecyl, M1 is Na, and n is 7.

[0088] In some embodiments of the present invention, R1 is H, R2 is methyl, R3 is tetradecyl, M1 is H, and n is 7.

[0089] In some embodiments of the present invention, R1 is H, R2 is H, R3 is hexadecyl, M1 is Na, and n is 15.

[0090] In some embodiments of the present invention, the content of the structural unit P is 85-99 wt% based on the total weight of the polymer, for example, it can be any one of 85 wt%, 86 wt%, 87 wt%, 88 wt%, 89 wt%, 90 wt%, 91 wt%, 92 wt%, 93 wt%, 94 wt%, 95 wt%, 96 wt%, 97 wt%, 98 wt%, 99 wt%, or a value within a range of any two of the above values. Preferably, the content of the structural unit P is 90-98 wt% based on the total weight of the polymer.

[0091] In some embodiments of the present invention, the content of structural unit B accounts for 10-35% by weight of the content of structural unit P, for example, it can be any one of 10% by weight, 11% by weight, 12% by weight, 13% by weight, 14% by weight, 15% by weight, 16% by weight, 17% by weight, 18% by weight, 19% by weight, 20% by weight, 21% by weight, 22% by weight, 23% by weight, 24% by weight, 25% by weight, 26% by weight, 27% by weight, 28% by weight, 29% by weight, 30% by weight, 31% by weight, 32% by weight, 33% by weight, 34% by weight, or a value within a range of any two of the above values. Preferably, the content of structural unit B accounts for 12-30% by weight of the content of structural unit P.

[0092] In some embodiments of the present invention, based on the total weight of the polymer, the total content of structural unit C and structural unit D is 1-15% by weight, for example, it can be any one of 1% by weight, 2% by weight, 3% by weight, 4% by weight, 5% by weight, 6% by weight, 7% by weight, 8% by weight, 9% by weight, 10% by weight, 11% by weight, 12% by weight, 13% by weight, 14% by weight, or a value within a range of any two of the above values. Preferably, based on the total weight of the polymer, the total content of structural unit C and structural unit D is 2-10% by weight.

[0093] In some embodiments of the present invention, the structural unit C accounts for 10-90% by weight of the total content of structural units C and D. For example, it can be any one of 10% by weight, 15% by weight, 20% by weight, 25% by weight, 30% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight, 80% by weight, 85% by weight, or 90% by weight, or a value within a range of any two of the above values. Preferably, the structural unit C accounts for 15-85% by weight of the total content of structural units C and D.

[0094] In some embodiments of the present invention, the structural unit D accounts for 10-90% by weight of the total content of structural unit C and structural unit D. For example, it can be any one of 10% by weight, 15% by weight, 20% by weight, 25% by weight, 30% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight, 80% by weight, 85% by weight, or 90% by weight, or a value within a range of any two of the above values. Preferably, the structural unit D accounts for 15-85% by weight of the total content of structural unit C and structural unit D.

[0095] In some embodiments of the present invention, the weight ratio of the structural unit P, the structural unit C, and the structural unit D is 1:(0.01-0.1):(0.01-0.1).

[0096] In some embodiments of the present invention, the polymer has a viscosity-average molecular weight of 8 million to 15 million.

[0097] In this invention, conventional methods in the prior art can be used to test the content of each structural unit in the polymer, such as infrared spectroscopy, nuclear magnetic resonance, and the amount of monomers fed during polymerization. Preferably, the content of each structural unit in the polymer is determined by the amount of monomers fed. Specifically, the actual feeding ratio of each monomer participating in polymerization is determined by testing the content of unreacted monomers, thereby determining the content of each structural unit in the polymer. Furthermore, in this invention, when the content of each unreacted monomer in the polymer is tested to be below 0.05% by weight, it indicates that all monomers have essentially participated in the polymerization reaction. Specifically, the content of the residual monomers is determined using liquid chromatography.

[0098] A fourth aspect of the present invention provides a method for preparing a polymer, the method comprising: under solution polymerization conditions, in the presence of an initiator, causing monomers to undergo a polymerization reaction to obtain a copolymer colloid; hydrolyzing the copolymer colloid or not hydrolyzing it; wherein the monomers include monomer P', monomer C' as shown in formula (7), monomer D' as shown in formula (8), and monomer P' being monomer A' as shown in formula (5) and / or monomer B' as shown in formula (6);

[0099]

[0100]

[0101] Wherein, R1 and R2 are H or methyl; M1 is H or an alkali metal; R3 is C6-C 18(e.g., C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18) alkyl (especially straight-chain alkyl); 4≤n≤19 (e.g., 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19).

[0102] In this invention, n is an integer.

[0103] In some embodiments of the present invention, M1 is H, sodium, or potassium.

[0104] In some embodiments of the present invention, R1 is H, R2 is H, R3 is octyl, M1 is Na, and n is 15.

[0105] In some embodiments of the present invention, R1 is H, R2 is H, R3 is nonyl, M1 is Na, and n is 9.

[0106] In some embodiments of the present invention, R1 is H, R2 is H, R3 is dodecyl, M1 is Na, and n is 7.

[0107] In some embodiments of the present invention, R1 is H, R2 is methyl, R3 is tetradecyl, M1 is H, and n is 7.

[0108] In some embodiments of the present invention, R1 is H, R2 is H, R3 is hexadecyl, M1 is Na, and n is 15.

[0109] In some embodiments of the present invention, based on the total weight of the monomers, the amount of monomer P' is 85-99 wt%, for example, it can be any one of 85 wt%, 86 wt%, 87 wt%, 88 wt%, 89 wt%, 90 wt%, 91 wt%, 92 wt%, 93 wt%, 94 wt%, 95 wt%, 96 wt%, 97 wt%, 98 wt%, 99 wt%, or a value within a range of any two of the above values. Preferably, based on the total weight of the monomers, the amount of monomer P' is preferably 90-98 wt%.

[0110] In some embodiments of the present invention, based on the total weight of the monomers, the total amount of monomer C' and monomer D' is 1-15% by weight, for example, it can be any one of 1% by weight, 2% by weight, 3% by weight, 4% by weight, 5% by weight, 6% by weight, 7% by weight, 8% by weight, 9% by weight, 10% by weight, 11% by weight, 12% by weight, 13% by weight, 14% by weight, or a value within the range of any two of the above values. Preferably, based on the total weight of the monomers, the total amount of monomer C' and monomer D' is preferably 2-10% by weight.

[0111] In some embodiments of the present invention, monomer C' accounts for 10-90% by weight of the total amount of monomers C' and D', for example, it can be any one of 10% by weight, 15% by weight, 20% by weight, 25% by weight, 30% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight, 80% by weight, 85% by weight, or a value within a range of any two of the above values. Preferably, monomer C' accounts for 15-85% by weight of the total amount of monomers C' and D'.

[0112] In some embodiments of the present invention, monomer D' accounts for 10-90% by weight of the total amount of monomer C' and monomer D', for example, it can be any one of 10% by weight, 15% by weight, 20% by weight, 25% by weight, 30% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight, 80% by weight, 85% by weight, or a value within a range of any two of the above values. Preferably, monomer D' accounts for 15-85% by weight of the total amount of monomer C' and monomer D'.

[0113] In some embodiments of the present invention, the monomer P' is monomer A' as shown in formula (5) and monomer B' as shown in formula (6), wherein the mass of monomer B' accounts for 10-35% by weight of monomer P', for example, it can be any one of 10% by weight, 11% by weight, 12% by weight, 13% by weight, 14% by weight, 15% by weight, 16% by weight, 17% by weight, 18% by weight, 19% by weight, 20% by weight, 21% by weight, 22% by weight, 23% by weight, 24% by weight, 25% by weight, 26% by weight, 27% by weight, 28% by weight, 29% by weight, 30% by weight, 31% by weight, 32% by weight, 33% by weight, 34% by weight, or a value within the range of any two of the above values. Preferably, the mass of monomer B' accounts for 12-30% by weight of monomer P'.

[0114] In this invention, the method may include a hydrolysis step, in which the structural unit A provided by monomer A' is partially hydrolyzed into structural unit B, in which case monomer B' may not be present in the monomer. Alternatively, the method may omit the hydrolysis step, in which case monomer B' may be present in the monomer, thereby obtaining a polymer having structural unit B. It should be understood that hydrolysis can be performed simultaneously with the presence of monomer B' in the monomer, or simultaneously with the absence of monomer B' in the monomer, as long as the content of structural unit B in the obtained polymer meets the requirements.

[0115] In some preferred embodiments of the present invention, the monomers include monomer A' as shown in formula (5), monomer C' as shown in formula (7), and monomer D' as shown in formula (8). Specifically, based on the total weight of the monomers, the amount of monomer A' is 85-99% by weight, preferably 90-98% by weight; based on the total weight of the monomers, the total amount of monomer C' and monomer D' is 1-15% by weight, preferably 2-10% by weight; monomer C' accounts for 10-90% by weight of the total amount of monomer C' and monomer D', preferably 15-85% by weight; and monomer D' accounts for 10-90% by weight of the total amount of monomer C' and monomer D', preferably 15-85% by weight.

[0116] In some preferred embodiments of the present invention, the monomers include monomer P', monomer C' as shown in formula (7), and monomer D' as shown in formula (8), wherein monomer P' is monomer A' and monomer B'. Based on the total weight of the monomers, the amount of monomer P' is 85-99% by weight, preferably 90-98% by weight; the amount of monomer B' is 10-35% by weight, preferably 12-30% by weight, of the amount of monomer P'. Based on the total weight of the monomers, the total amount of monomer C' and monomer D' is 1-15% by weight, preferably 2-10% by weight; monomer C' is 10-90% by weight, preferably 15-85% by weight, of the total amount of monomer C' and monomer D'; and monomer D' is 10-90% by weight, preferably 15-85% by weight, of the total amount of monomer C' and monomer D'.

[0117] In some embodiments of the present invention, the polymerization reaction is initiated by at least one of photoinitiation, thermal initiation, radiation initiation, and redox initiation.

[0118] The initiator described in this invention can be a commonly used initiator in the art, such as at least one of azo initiators, redox initiators, and photoinitiators. The amount of initiator used is the conventional amount, and those skilled in the art can select the initiator and the amount of initiator according to the actual situation.

[0119] In some embodiments of the present invention, the initiator is an azo initiator and / or a redox initiator.

[0120] In some embodiments of the present invention, the amount of the initiator is 0.0001-0.3% by weight of the total weight of the monomer, preferably 0.01-0.1% by weight.

[0121] In some embodiments of the present invention, the amount of the azo initiator is 0.0001-0.1% by weight of the total weight of the monomers.

[0122] In some embodiments of the present invention, the amount of the redox initiator is 0.0002-0.3% by weight of the total weight of the monomers.

[0123] In some embodiments of the present invention, the azo initiator is a water-soluble azo initiator.

[0124] In some embodiments of the present invention, the water-soluble azo initiator is at least one selected from 2,2'-azobis(2-amidinylpropane) dihydrochloride, 2,2'-azobis(2-imidazolinepropane) dihydrochloride, and 4,4'-azobis(4-cyanopentanoic acid).

[0125] In some embodiments of the present invention, the redox initiator includes an oxidant and a reducing agent;

[0126] In some embodiments of the present invention, the reducing agent is at least one of inorganic reducing agents and organic reducing agents.

[0127] In some embodiments of the present invention, the mass ratio of the oxidant to the reducing agent is (0.1-1):1.

[0128] In some embodiments of the present invention, the inorganic reducing agent is at least one of ferrous sulfate, ferrous ammonium sulfate, cuprous chloride, potassium sulfite, sodium sulfite, ammonium bisulfite, potassium bisulfite, sodium thiosulfate, potassium thiosulfate, and sodium bisulfite.

[0129] In some embodiments of the present invention, the organic reducing agent is at least one selected from N,N-dimethylethanolamine, N,N'-dimethylpiperazine, N,N,N',N'-tetramethylurea and N,N,N',N'-tetramethylethylenediamine.

[0130] In some embodiments of the present invention, the oxidant is at least one of benzoyl peroxide, hydrogen peroxide, tert-butyl hydroperoxide, 2,5-dimethyl-2,5-bis(hydrogen peroxide)hexane, ammonium persulfate, sodium persulfate, and potassium persulfate.

[0131] In some embodiments of the present invention, the photoinitiator is at least one of 2-hydroxy-2,2-dimethylacetophenone and 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylacetophenone.

[0132] In some embodiments of the present invention, the redox initiator is a persulfate oxidant and a sulfite reducing agent.

[0133] In some embodiments of the present invention, the persulfate oxidant is potassium persulfate and / or ammonium persulfate.

[0134] In some embodiments of the present invention, the sulfite may be, for example, potassium bisulfite and / or sodium bisulfite.

[0135] In some embodiments of the present invention, the persulfate oxidant is 0.01-0.1 parts by weight relative to 100 parts by weight of the monomer.

[0136] In some embodiments of the present invention, the sulfite reducing agent is 0.005-0.05 parts by weight relative to 100 parts by weight of the monomer.

[0137] In some embodiments of the present invention, the monomer undergoes polymerization in the form of a monomer solution. The amount of solvent used is not critical, as long as the solute is sufficiently dissolved. Preferably, the solvent for the monomer solution is water. More preferably, the total monomer content in the monomer solution can be 10-50% by weight, preferably 15-35% by weight. More preferably, the pH value of the monomer solution is 5-12, preferably 6-11.

[0138] In some embodiments of the present invention, the preparation method of the monomer solution can be a conventional technique in the art, for example: adding monomer C' and monomer D' to water, stirring until fully dissolved to obtain a functional monomer solution; adding monomer Q' to water, stirring thoroughly to obtain a monomer Q' solution; and mixing the functional monomer solution and the monomer Q' solution to obtain the monomer solution. Preferably, the method further includes adjusting the temperature of the obtained monomer solution to 0-30°C, and preferably adjusting the pH of the monomer solution to 5-12.

[0139] In some embodiments of the present invention, the conditions for the hydrolysis reaction include: a temperature of 70-90°C and a time of 2-24 hours.

[0140] In some embodiments of the present invention, the hydrolysis reaction is carried out under alkaline conditions. Preferably, the alkaline conditions can be achieved by adding an alkaline substance, preferably sodium hydroxide and / or potassium hydroxide. The amount of alkaline substance added is not particularly limited and can be adjusted by those skilled in the art according to the needs of the reaction. In some embodiments of the present invention, the alkaline substance can be added after the polymerization reaction or before the polymerization reaction.

[0141] In some embodiments of the present invention, the conditions for the solution polymerization reaction include: a temperature of 0-30°C, preferably 0-25°C; a time of 4-10 h; and a pH value of 5-12. The pH value can be adjusted using methods commonly used in the prior art, such as by adding alkaline substances like sodium hydroxide or acidic substances like acrylic acid or 2-acrylamido-2-methylpropanesulfonic acid.

[0142] In some embodiments of the present invention, the solution polymerization reaction is further subjected to an inert atmosphere. Preferably, the inert atmosphere is provided by nitrogen.

[0143] In some preferred embodiments of the present invention, the initiator is a composite initiator system composed of an azo initiator and a redox initiator. The conditions for the solution polymerization reaction include: the solution polymerization reaction is carried out under an inert atmosphere, at a temperature of 0-30°C, for a time of 4-10 hours, and at a pH value of 5-12. Preferably, the inert atmosphere can be provided by nitrogen. The pH value can be adjusted using methods commonly used in the prior art, such as by adding alkaline substances like sodium hydroxide or acidic substances like acrylic acid or 2-acrylamido-2-methylpropanesulfonic acid.

[0144] In some embodiments of the present invention, the solution polymerization reaction is further described as being carried out in the presence of a complexing agent. The complexing agent is added during the solution polymerization reaction to reduce interference from impurities during the polymerization process.

[0145] In some embodiments of the present invention, the complexing agent is at least one of ethylenediaminetetraacetic acid disodium salt (EDTA-2Na), sodium aminotriacetate, and diethylenetriaminepentacarboxylate.

[0146] In some embodiments of the present invention, the amount of the complexing agent is 0.01-0.1% by weight of the total weight of the monomers, preferably 0.02-0.05% by weight.

[0147] In some embodiments of the present invention, the method further includes granulating the copolymer colloid. The granulation can be performed before or after hydrolysis, with or without hydrolysis.

[0148] In some embodiments of the present invention, the method further includes granulating the copolymer colloid before or without hydrolysis.

[0149] In some embodiments of the present invention, the method further includes: pulverizing and sieving the copolymer colloid after hydrolysis or without hydrolysis.

[0150] In a preferred embodiment of the present invention, the preparation method includes:

[0151] 1) Add monomers C' and D' to deionized water, stir until fully dissolved, and obtain a functional monomer solution;

[0152] 2) Add monomer A' and / or monomer B' to deionized water and stir until homogeneous to obtain monomer P' solution;

[0153] 3) Add monomer P' solution to the functional monomer solution, stir thoroughly, adjust the pH to 5-12, and adjust the temperature to 0℃-30℃ to obtain the monomer solution;

[0154] 4) After pouring the monomer solution into the reactor, inert gas is bubbled in for 5-40 minutes. Then, the complex, azo initiator and redox initiator are added in sequence. Inert gas is bubbled in continuously. When the system begins to become viscous, the inert gas is stopped. After sealing, the solution polymerization reaction is carried out for 4-10 hours to obtain the copolymer colloid.

[0155] 5) The colloid is removed and then granulated, hydrolyzed or not hydrolyzed, dried, pulverized and sieved to obtain the polymer.

[0156] The fifth aspect of the present invention provides a polymer prepared by the method described above.

[0157] The sixth aspect of the present invention provides the application of the polymer as described above in oil displacement.

[0158] In some embodiments of the present invention, the application is an application in oil reservoir development.

[0159] In some embodiments of the present invention, the reservoir is a conventional reservoir, a high-temperature and high-salinity reservoir, or a common heavy oil reservoir.

[0160] In some embodiments of the present invention, the application is as a modulator / depressant.

[0161] In some embodiments of the present invention, the application is as a profile improver.

[0162] This invention introduces monomers C' and D' into the macromolecular chain of polyacrylamide simultaneously. The resulting polymer exhibits high viscosity under conditions of 20-85℃ and a salinity of 500-50000 mg / L, preferably 30-80℃ and a salinity of 1000-20000 mg / L. This effectively improves the oil-water mobility ratio and is suitable for use as a modifier and profile improver in conventional reservoirs, high-temperature and high-salinity reservoirs, and ordinary heavy oil reservoirs.

[0163] The present invention will be described in detail below through embodiments. In the following embodiments,

[0164] Unless otherwise specified, all raw materials are commercially sourced.

[0165] Acrylamide crystals (monomer A') were purchased from Shandong Nuoer Biotechnology Co., Ltd.

[0166] Sodium acrylate (monomer B') was purchased from Innocare Technology Co., Ltd.

[0167] N-hexylacrylamide, N-octylacrylamide, N-nonylacrylamide, N-dodecylacrylamide, N-tetradecylacrylamide, N-hexadecylacrylamide, and N-octadecylacrylamide as monomers C' are commercially available from Inokai Technology Co., Ltd.

[0168] The testing method is as follows:

[0169] 1) Determination of residual monomer content

[0170] Residual monomer A' content: The residual acrylamide (monomer A') content of the polymer was determined according to the enterprise standard Q / SH1020 1572-2017 "Polyacrylamide for Oil Displacement" of China Petrochemical Corporation Shengli Oilfield Administration Bureau.

[0171] Residual monomer B', C', and D' content: The method for determining the residual acrylamide content of polymers was based on the enterprise standard Q / SH10201572-2017 "Polyacrylamide for Oil Displacement" of China Petrochemical Corporation Shengli Oilfield Administration Bureau. The difference was that in the preparation method of the standard sample, acrylamide was replaced with monomers B', C', and D', respectively.

[0172] 2) Apparent viscosity was measured using a Brookfield viscometer in simulated water at temperatures of 30℃ and 80℃ and a mineralization of 10,000-20,000 mg / L.

[0173] 3) The viscosity-average molecular weight of the polymer is determined by the formula M = ([η] / K) as specified in GB / T 12005.10-92. 1 / α To calculate, where K = 4.75 × 10 -3 α=0.8, [η] is the intrinsic viscosity; the intrinsic viscosity was determined according to the enterprise standard Q / SH1020 1572-2017 "Polyacrylamide for Oil Displacement" of Shengli Oilfield Administration Bureau of China Petrochemical Corporation.

[0174] Unless otherwise specified, in the following preparation examples, embodiments and comparative examples, "room temperature" refers to 25°C.

[0175] Preparation Example 1

[0176] Preparation Example 1 is used to illustrate the monomer D' (compound M1) and its preparation method provided by the present invention.

[0177] At room temperature (25°C), ethylene glycol (6.207 g, 100 mmol) was added, followed by 100 mL of anhydrous tetrahydrofuran for dissolution. After complete dissolution, sodium hydride was added in three portions, with a total amount of 2.8 g. The reaction was allowed to proceed for 30 minutes. Then, hexadecane bromodiphenyl ether (33.587 g, 110 mmol) was slowly added dropwise (approximately 15 mmol / min). After the addition was complete, the reaction was continued for 2 hours. After the reaction was completed, the reaction system was quenched with water, and the solid was removed by filtration. Unreacted hexadecane bromodiphenyl ether was removed by vacuum distillation. The mixture was cooled to room temperature to obtain an intermediate (14.325 g, 50 mmol). Pyridine (6.328 g, 80 mmol) was added, followed by SOCl2 (8.922 g, 75 mmol) added dropwise at a slow rate (approximately 7.5 mmol / min). After the addition was complete, the reaction was allowed to proceed at 70°C for 10 hours. The reaction was stopped, cooled to room temperature, and allowed to stand to separate into layers. The upper organic layer was taken, the pH was adjusted to 8.3, washed 6 times with water, and dried by rotary evaporation to obtain intermediate IM1 (8.538 g, 28 mmol).

[0178] 5-Hydroxyindole (7,989 g, 60 mmol) was dissolved in 200 mL of anhydrous THF, followed by the addition of triethylamine (7.083 g, 70 mmol). The mixture was stirred at 25°C for 30 minutes. The mixture was then cooled to 0°C in an ice-water bath, and acryloyl chloride (6.336 g, 70 mmol) was slowly added dropwise (approximately 7.0 mmol / min) while maintaining a constant temperature. After the addition was complete, the mixture was allowed to slowly return to 25°C and stirred overnight (approximately 10 hours). After the reaction was complete, the reaction mixture was quenched dropwise with water. The reaction product was extracted with diethyl ether (75 mL × 3), and the organic phase was dried over Na₂SO₄. The product was then recrystallized (using a mixture of n-hexane and dichloromethane in a 4:1 volume ratio) to obtain a white solid IM₂ (4.68 g, 25 mmol).

[0179] IM2 (4.68 g, 25 mmol) was dissolved in tetrahydrofuran (200 mL), and potassium carbonate (4.416 g, 30 mmol) was added. After stirring and homogenization, the mixture was heated to 75 °C, and intermediate IM1 (8.538 g, 28 mmol) was added. The mixture was refluxed for 8 hours. After the reaction was completed, the mixture was allowed to cool to room temperature, and then the reaction system was quenched with water. The pH of the mixture was then adjusted to 3 with dilute hydrochloric acid solution. The reaction product was extracted with diethyl ether (75 mL × 3), washed four times with saturated sodium chloride, dried over Na2SO4, and recrystallized after rotary evaporation (the recrystallization solvent was a mixture of dichloromethane and petroleum ether in a volume ratio of 4:1) to obtain compound M1 (5.924 g, 13 mmol).

[0180] The reaction process is as follows: (1)

[0182] (2)

[0184] (3)

[0186]

[0187] The structural identification of M1 is as follows:

[0188] 1 H NMR (300MHz, CDCl3) δ: 7.95 (dd, 2H), 7.65 (dd, 1H), 6.61 (dd, 1H), 6.39 (dd, 1H), 6.32 (t, 1H), 6.09 (dd, 1H) ,6.03(dd,1H),4.32(t,2H),3.78(t,2H),3.36(t,2H),1.42-1.52(m,4H),1.26-1.30(m,24H),0.88(t,3H);

[0189] 13 C NMR (75MHz, CDCl3) δ: 165.2, 153.5, 131.9, 130.1, 127.4, 122.0, 115.9, 112.4, 111.8, 107.9, 70.7, 70.1, 69.4, 31.9, 30.1, 29.6, 22.8, 14.2.

[0190] As can be seen from the above results, M1 has the structure shown in equation (8), where n = 15.

[0191] Preparation Example 2

[0192] Preparation Example 2 is used to illustrate the monomer D' (compound M2) and its preparation method provided by the present invention.

[0193] At room temperature (25°C), ethylene glycol (6.207 g, 100 mmol) was added, followed by 100 mL of anhydrous tetrahydrofuran for dissolution. After complete dissolution, sodium hydride was added in three portions, with a total amount of 3.0 g. The reaction was allowed to proceed for 30 minutes. Then, bromodecane (22.118 g, 100 mmol) was slowly added dropwise (approximately 15 mmol / min). After the addition was complete, the reaction was continued for 2 hours. After the reaction was completed, the reaction system was quenched with water, and the solid was removed by filtration. Unreacted bromodecane was removed by vacuum distillation. The mixture was cooled to room temperature to obtain an intermediate (9.712 g, 48 mmol). Pyridine (4.746 g, 60 mmol) was added, followed by slow dropwise addition of SOCl2 (6.900 g, 58 mmol) (approximately 6.0 mmol / min). After the addition was complete, the reaction was allowed to proceed at 70°C for 10 hours. The reaction was stopped, cooled to room temperature, and allowed to stand to separate into layers. The upper organic layer was taken, the pH was adjusted to 8.3, washed 6 times with water, and dried by rotary evaporation to obtain intermediate IM3 (5.520 g, 25 mmol).

[0194] The preparation process of IM2 is the same as that in Preparation Example 1.

[0195] IM2 (4.493 g, 24 mmol) was dissolved in tetrahydrofuran (200 mL), and potassium carbonate (4.122 g, 28 mmol) was added. After stirring and homogenization, the mixture was heated to 75 °C, and intermediate IM3 (5.520 g, 25 mmol) was added. The mixture was refluxed for 8 hours. After the reaction was completed, the mixture was allowed to cool to room temperature, and then the reaction system was quenched with water. The pH of the mixture was then adjusted to 3 with dilute hydrochloric acid solution. The reaction product was extracted with diethyl ether (75 mL × 3), washed five times with saturated sodium chloride, dried over Na2SO4, and recrystallized after rotary evaporation (the recrystallization solvent was a mixture of dichloromethane and petroleum ether in a volume ratio of 4:1) to obtain compound M2 (4.458 g, 12 mmol).

[0196] The reaction process is as follows: (1)

[0198] (2)

[0200]

[0201] The structural identification of M2 is as follows:

[0202] 1H NMR (300MHz, CDCl3) δ: 7.94 (dd, 2H), 7.63 (dd, 1H), 6.59 (dd, 1H), 6.38 (dd, 1H), 6.30 (t, 1H), 6.08 (dd, 1H) ,6.00(dd,1H),4.31(t,2H),3.76(t,2H),3.35(t,2H),1.42-1.55(m,4H),1.25-1.31(m,12H),0.87(t,3H);

[0203] 13 C NMR (75MHz, CDCl3) δ: 165.1, 153.3, 131.8, 129.9, 127.3, 121.7, 115.8, 112.2, 111.7, 107.6, 70.5, 69.9, 69.2, 31.8, 30.0, 29.4, 22.6, 14.0.

[0204] As can be seen from the above results, M2 has the structure shown in equation (8), where n = 9.

[0205] Preparation Example 3

[0206] Preparation Example 3 is used to illustrate the monomer D' (compound M3) and its preparation method provided by the present invention.

[0207] At room temperature (25°C), ethylene glycol (6.207 g, 100 mmol) was added, followed by dissolution with 100 mL of anhydrous tetrahydrofuran. After complete dissolution, sodium hydride was added in three portions, totaling 2.64 g. The reaction was allowed to proceed for 30 minutes, followed by slow dropwise addition of n-octane bromide (21.24 g, 110 mmol) (approximately 10 mmol / min). After the addition was complete, the reaction was continued for 2 hours. After the reaction was complete, the reaction system was quenched with water, and then NaBr was removed by filtration. Unreacted n-octane bromide was removed by vacuum distillation. The mixture was cooled to room temperature to obtain an intermediate (11.563 g, 60 mmol). Pyridine (6.328 g, 80 mmol) was added, followed by slow dropwise addition of excess SOCl2 (9.992 g, 84 mmol) (approximately 8.0 mmol / min). The reaction was allowed to proceed at 70°C for 11 hours. The reaction was stopped, cooled to room temperature, and allowed to separate into layers. The upper organic layer was collected, the pH was adjusted to 8.3, and the mixture was washed six times with water. After rotary evaporation and drying, intermediate IM4 (6.746 g, 35 mmol) was obtained.

[0208] The preparation process of IM2 is the same as that in Preparation Example 1.

[0209] IM2 (5.616 g, 30 mmol) was dissolved in tetrahydrofuran (200 mL), and potassium carbonate (5.889 g, 40 mmol) was added. After stirring and homogenization, the mixture was heated to 75 °C, and intermediate IM4 (6.746 g, 35 mmol) was added. The mixture was refluxed for 8 hours. After the reaction was completed, the mixture was allowed to cool to room temperature, and then the reaction system was quenched with water. The pH of the mixture was then adjusted to 3 with dilute hydrochloric acid solution. The reaction product was extracted with diethyl ether (75 mL × 3), washed three times with saturated sodium chloride, dried over Na2SO4, and recrystallized after rotary evaporation (the recrystallization solvent was a mixture of dichloromethane and petroleum ether in a volume ratio of 4:1) to obtain compound M2 (5.496 g, 16 mmol).

[0210] The reaction process is as follows: (1)

[0212] (2)

[0214]

[0215] The structural identification of M3 is as follows:

[0216] 1 H NMR (300MHz, CDCl3) δ: 7.93 (dd, 2H), 7.64 (dd, 1H), 6.81 (dd, 1H), 6.37 (dd, 1H), 6.29 (t, 1H), 6.09 (dd, 1H) ,6.01(dd,1H),4.29(t,2H),3.75(t,2H),3.34(t,2H),1.40-1.50(m,4H),1.25-1.30(m,8H),0.86(t,3H);

[0217] 13 C NMR (75MHz, CDCl3) δ: 165.0, 153.2, 131.6, 129.8, 127.2, 121.8, 121.5, 115.6, 112.3, 111.5, 107.7, 70.6, 70.0, 69.1, 31.7, 29.9, 22.5, 13.9.

[0218] As can be seen from the above results, M3 has the structure shown in equation (8), where n = 7.

[0219] Example 1

[0220] This embodiment illustrates a high-viscosity functional polymer for oil displacement and its preparation method.

[0221] Add 2g of N-octylacrylamide and 2.5g of monomer D' (M1 in Preparation Example 1) to 40g of deionized water and stir until homogeneous to obtain a functional monomer solution. Take 45g of acrylamide monomer and add it to 150g of water, stir until homogeneous, and then add it to the functional monomer solution. Make up the total weight with deionized water to 300g, adjust the pH to 6, and control the initial temperature at 0℃. Nitrogen gas was bubbled into the system for 20 minutes to remove oxygen. Then, 0.02 g of EDTA-2Na, 1 g of 0.25 wt% aqueous solution of 2,2-azobis(2-amidinepropane) dihydrochloride, 3 g of 0.2 wt% aqueous solution of ammonium persulfate, and 1.5 g of 0.6 wt% aqueous solution of sodium bisulfite were added to initiate polymerization. After the system became viscous, nitrogen bubbling was stopped, and the reaction continued for 4 hours. After polymerization was completed, the resulting colloid was granulated, and 5.07 g of sodium hydroxide was added for hydrolysis at 70 °C for 8 hours. The granules were then dried at 60 °C until the solid content reached 89 wt%. The granules were pulverized and sieved to obtain the polymer dry powder product.

[0222] Based on the amount of feed and the content of residual acrylamide (content of residual monomer A'), monomer A was approximately completely converted into structural units; based on the amount of sodium hydroxide added, the content of structural unit A was 72.7% by weight and the content of structural unit B was 18.2% by weight, with the total weight of the polymer as the baseline.

[0223] Based on the amount of feed and the content of residual monomers C' and D', it is determined that monomers C' and D' are approximately completely converted into structural units.

[0224] The polymer has a viscosity-average molecular weight of 13 million.

[0225] The residual monomer A' content of the obtained polymer dry powder product was determined, as were the apparent viscosity of a 2000 mg / L polymer solution in simulated water at 30℃ and 10000 mg / L mineralization, the apparent viscosity of a 2000 mg / L polymer solution in simulated water at 80℃ and 10000 mg / L mineralization, and the apparent viscosity of a 2000 mg / L polymer solution in simulated water at 80℃ and 20000 mg / L mineralization. The results are shown in Table 1.

[0226] Example 2

[0227] This embodiment illustrates a high-viscosity functional polymer for oil displacement and its preparation method.

[0228] Add 2.5g of N-nonylacrylamide and 2.5g of monomer D' (M2 in Preparation Example 2) to 40g of deionized water and stir until homogeneous to obtain a functional monomer solution. Take 55g of acrylamide monomer and add it to 150g of water, stir until homogeneous, and then add it to the functional monomer solution. Make up the total weight with deionized water to 300g, adjust the pH to 6, and control the initial temperature at 0℃. Nitrogen gas was bubbled into the system for 20 minutes to remove oxygen. Then, 0.02 g of EDTA-2Na, 1 g of 0.25 wt% aqueous solution of 2,2-azobis(2-amidinepropane) dihydrochloride, 4.5 g of 0.2 wt% aqueous solution of ammonium persulfate, and 1.5 g of 0.6 wt% aqueous solution of sodium bisulfite were added to initiate polymerization. After the system became viscous, nitrogen bubbling was stopped, and the reaction continued for 4 hours. After polymerization was completed, the resulting colloid was granulated, and 5.58 g of sodium hydroxide was added for hydrolysis at 70 °C for 8 hours. The granules were then dried at 60 °C until the solid content reached 89 wt%. The granules were pulverized and sieved to obtain the polymer powder product.

[0229] Based on the amount of feed and the content of residual acrylamide (content of residual monomer A'), it was determined that monomer A was approximately completely converted into structural units; based on the amount of sodium hydroxide added, the content of structural unit A was 75.2% by weight and the content of structural unit B was 16.5% by weight, with the total weight of the polymer as the baseline.

[0230] Based on the amount of feed and the content of residual monomers C' and D', it is determined that monomers C' and D' are approximately completely converted into structural units.

[0231] The polymer has a viscosity-average molecular weight of 14.5 million.

[0232] The residual monomer A' content of the obtained polymer dry powder product was determined, as were the apparent viscosity of a 2000 mg / L polymer solution in simulated water at 30℃ and 10000 mg / L mineralization, the apparent viscosity of a 2000 mg / L polymer solution in simulated water at 80℃ and 10000 mg / L mineralization, and the apparent viscosity of a 2000 mg / L polymer solution in simulated water at 80℃ and 20000 mg / L mineralization. The results are shown in Table 1.

[0233] Example 3

[0234] This embodiment illustrates a high-viscosity functional polymer for oil displacement and its preparation method.

[0235] Add 1.5g of N-dodecylacrylamide and 1.5g of monomer D' (M3 in Preparation Example 3) to 40g of deionized water, and stir until homogeneous to obtain a functional monomer solution. Take 52g of acrylamide monomer and 13g of sodium acrylate and add them to 150g of water, stir until homogeneous, and then add them to the functional monomer solution. Add water with deionized water to bring the total weight to 300g, adjust the pH to 6, and control the initial temperature at 0℃. Purge the system with nitrogen for 20min to remove oxygen. Then add 0.02g of EDTA-2Na, 1g of 0.25wt% 2,2-azobis(2-amidinepropane) dihydrochloride aqueous solution, 3.5g of 0.2wt% ammonium persulfate aqueous solution, and 1.5g of 0.6wt% sodium bisulfite aqueous solution to initiate polymerization. After the system becomes viscous, stop purging with nitrogen and continue the reaction for 4 hours. After polymerization is complete, granulate the obtained colloid, dry it at 60℃ until the solid content reaches 89wt%, pulverize and sieve to obtain the polymer dry powder product.

[0236] Based on the amount of feed and the content of residual monomers A', B', C', and D', it is determined that monomers A', B', C', and D' are approximately completely converted into structural units.

[0237] The polymer has a viscosity-average molecular weight of 9.6 million.

[0238] The residual monomer A' content of the obtained polymer dry powder product was determined, as were the apparent viscosity of a 2000 mg / L polymer solution in simulated water at 30℃ and 10000 mg / L mineralization, the apparent viscosity of a 2000 mg / L polymer solution in simulated water at 80℃ and 10000 mg / L mineralization, and the apparent viscosity of a 2000 mg / L polymer solution in simulated water at 80℃ and 20000 mg / L mineralization. The results are shown in Table 1.

[0239] Example 4

[0240] This embodiment illustrates a high-viscosity functional polymer for oil displacement and its preparation method.

[0241] Add 1g of N-tetradecylacrylamide and 4g of monomer D' (M3 in Preparation Example 3) to 40g of deionized water, and stir until homogeneous to obtain a functional monomer solution. Take 60g of acrylamide monomer and 10g of methacrylic acid and add them to 150g of water, stir until homogeneous, and then add them to the functional monomer solution. Add water with deionized water to bring the total weight to 300g, adjust the pH to 6, and control the initial temperature at 5℃. Purge the system with nitrogen for 20min to remove oxygen. Then add 0.03g of EDTA-2Na, 1.0g of 0.25wt% 2,2-azobis(2-amidinepropane) dihydrochloride aqueous solution, 4g of 0.2wt% ammonium persulfate aqueous solution, and 1.5g of 0.6wt% sodium bisulfite aqueous solution to the system to initiate polymerization. After the system becomes viscous, stop purging with nitrogen and continue the reaction for 4 hours. After polymerization is complete, granulate the obtained colloid, dry it at 60℃ until the solid content reaches 89wt%, pulverize and sieve to obtain the polymer dry powder product.

[0242] Based on the amount of feed and the content of residual monomers A', B', C', and D', it is determined that monomers A', B', C', and D' are approximately completely converted into structural units.

[0243] The polymer has a viscosity-average molecular weight of 8.2 million.

[0244] The residual monomer A' content of the obtained polymer dry powder product was determined, as were the apparent viscosity of a 2000 mg / L polymer solution in simulated water at 30℃ and 10000 mg / L mineralization, the apparent viscosity of a 2000 mg / L polymer solution in simulated water at 80℃ and 10000 mg / L mineralization, and the apparent viscosity of a 2000 mg / L polymer solution in simulated water at 80℃ and 20000 mg / L mineralization. The results are shown in Table 1.

[0245] Example 5

[0246] This embodiment illustrates a high-viscosity functional polymer for oil displacement and its preparation method.

[0247] Add 3g of N-hexadecylacrylamide and 2g of monomer D' (M1 in Preparation Example 1) to 40g of deionized water, and stir until homogeneous to obtain a functional monomer solution. Take 65g of acrylamide monomer and add it to 150g of water, stir until homogeneous, and then add it to the functional monomer solution. Make up the total weight with deionized water to 300g, adjust the pH to 6.0, and control the initial temperature at 5℃. Nitrogen gas was bubbled into the system for 20 minutes to remove oxygen. Then, 0.03 g of EDTA-2Na, 1.0 g of 0.25% aqueous solution of 2,2-azobis(2-amidinepropane) dihydrochloride, 4.5 g of 0.2 wt% aqueous solution of ammonium persulfate, and 1.5 g of 0.6% aqueous solution of sodium bisulfite were added to initiate polymerization. After the system became viscous, nitrogen bubbling was stopped, and the reaction continued for 4 hours. After polymerization was completed, the resulting colloid was granulated, and 7.32 g of sodium hydroxide was added to hydrolyze it at 70°C for 6 hours. The granules were then dried at 60°C until the solid content reached more than 89%. The granules were then pulverized and sieved to obtain the polymer dry powder product.

[0248] Based on the feed rate and residual acrylamide content (residual monomer A' content), monomer A' was approximately completely converted into structural units. Based on the amount of sodium hydroxide added, and using the total weight of the polymer as a baseline, the content of structural unit A was 74.3% by weight, and the content of structural unit B was 18.6% by weight.

[0249] Based on the amount of feed and the content of residual monomers C' and D', it is determined that monomers C' and D' are approximately completely converted into structural units.

[0250] The polymer has a viscosity-average molecular weight of 11.5 million.

[0251] The residual monomer A' content of the obtained polymer dry powder product was determined, as were the apparent viscosity of a 2000 mg / L polymer solution in simulated water at 30℃ and 10000 mg / L mineralization, the apparent viscosity of a 2000 mg / L polymer solution in simulated water at 80℃ and 10000 mg / L mineralization, and the apparent viscosity of a 2000 mg / L polymer solution in simulated water at 80℃ and 20000 mg / L mineralization. The results are shown in Table 1.

[0252] Comparative Example 1

[0253] Same as Example 1, except that monomer D' is not added.

[0254] Based on the feed rate and residual acrylamide content (residual monomer A' content), monomer A' was approximately completely converted into structural units. Based on the amount of sodium hydroxide added, and using the total weight of the polymer as a baseline, the content of structural unit A was 76.6% by weight, and the content of structural unit B was 19.1% by weight.

[0255] Based on the amount of feed and the content of residual monomer C', it is determined that monomer C' is approximately completely converted into structural units.

[0256] The polymer has a viscosity-average molecular weight of 14 million.

[0257] The residual monomer A' content of the obtained polymer dry powder product was determined, as were the apparent viscosity of a 2000 mg / L polymer solution in simulated water at 30℃ and 10000 mg / L mineralization, the apparent viscosity of a 2000 mg / L polymer solution in simulated water at 80℃ and 10000 mg / L mineralization, and the apparent viscosity of a 2000 mg / L polymer solution in simulated water at 80℃ and 20000 mg / L mineralization. The results are shown in Table 1.

[0258] Table 1 Evaluation of basic properties of polymers

[0259]

[0260]

[0261] As shown in the table above, the apparent viscosity of Examples 1-5 is higher than that of the comparative example. Furthermore, the apparent viscosity of Examples 1-5 exhibits a temperature-increasing viscosity trend with increasing temperature. When the mineralization is fixed at 10000 mg / L, the viscosity at 80℃ is greater than that at 30℃, demonstrating a unique temperature-increasing viscosity. Simultaneously, at 80℃, even when the mineralization increases from 10000 mg / L to 20000 mg / L, the polymer solution maintains a high viscosity, indicating good salt resistance at high mineralization. This demonstrates that introducing cyclic rigid long-chain monomers into the system enhances the rigidity of the polymer chains. The steric hindrance effectively resists the compression of the polymer chains at high temperatures and high mineralization. Furthermore, the introduction of long-chain nonpolar groups provides intermolecular forces, forming nonpolar aggregation regions in the solution environment (at a certain temperature and mineralization), resulting in unique high-efficiency viscosity enhancement in the aqueous phase at high temperatures and high mineralization.

[0262] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A compound, characterized in that, The compound has the structure shown in formula (8): Equation (8) Where 7 ≤ n ≤ 19.

2. The method for preparing the compound according to claim 1, characterized in that, The preparation method includes the following steps: (1) Under alkylation reaction conditions, ethylene glycol is successively reacted with sodium hydride and bromoalkane in the first and second contacts to obtain a structure such as HO-(CH2)2-O-(CH2). n -CH3 monosubstituted alcohol ethers; (2) Under chlorination reaction conditions, the monosubstituted alcohol ether obtained in step (1) is subjected to a third contact with thionyl chloride to obtain a structure such as Cl-(CH2)2-O-(CH2). n -CH3 chloro alcohol ethers; (3) Under amidation reaction conditions, 5-hydroxyindole is reacted with acryloyl chloride in a fourth contact to obtain amidated hydroxyindole; (4) Under the etherification reaction conditions, the chlorool ether obtained in step (2) is subjected to a fifth contact with the amidated hydroxyindole obtained in step (3).

3. The preparation method according to claim 2, wherein, The bromoalkane is selected from at least one of 1-bromooctane, 1-bromononane, 1-bromodecane, 1-bromoundecane, 1-bromododecane, 1-bromotridecane, 1-bromotetradecane, 1-bromopentadecanane, bromohexadecane, 1-bromoheptadecane, 1-bromooctadecane, and bromoeicosane.

4. The preparation method according to claim 2, wherein, The amount of sodium hydride used is 1-1.5 mol relative to 1 mol of ethylene glycol; And / or, relative to 1 mol of ethylene glycol, the amount of the bromoalkane is 0.8-1.5 mol; And / or, relative to 1 mol of ethylene glycol, the amount of thionyl chloride used is 0.3-1.5 mol; And / or, relative to 1 mol of 5-hydroxyindole, the amount of acryloyl chloride used is 0.5-1.5 mol.

5. The preparation method according to claim 4, wherein, The amount of the bromoalkane is 0.9-1.3 mol relative to 1 mol of ethylene glycol; And / or, relative to 1 mol of ethylene glycol, the amount of thionyl chloride used is 0.4-1.2 mol; And / or, relative to 1 mol of 5-hydroxyindole, the amount of acryloyl chloride used is 0.8-1.2 mol.

6. The preparation method according to any one of claims 2-5, wherein, In step (1), the alkylation reaction conditions include: a reaction temperature of 0-35℃; And / or, the duration of the first contact is 20-60 minutes; And / or, in step (1), the second contact time is 1.5-6 hours; And / or, in step (2), the chlorination reaction conditions include: a reaction temperature of 60-90℃; And / or, in step (2), the duration of the third contact is 8-12 hours; And / or, in step (3), the amidation reaction conditions include: a reaction temperature of 0-35°C; And / or, in step (3), the fourth contact time is 6-15 hours; And / or, in step (4), the etherification reaction conditions typically include a reaction temperature of 60-90°C; And / or, in step (4), the fifth contact time is 3-10 hours.

7. The preparation method according to claim 6, wherein, In step (1), the alkylation reaction conditions include: a reaction temperature of 15-30℃; And / or, the duration of the first contact is 25-45 minutes; And / or, in step (1), the second contact time is 2-4 hours; And / or, in step (2), the chlorination reaction conditions include: a reaction temperature of 65-75℃; And / or, in step (2), the duration of the third contact is 10-11 hours; And / or, in step (3), the amidation reaction conditions include: a reaction temperature of 10-25°C; And / or, in step (3), the fourth contact time is 8-10 hours; And / or, in step (4), the etherification reaction conditions typically include a reaction temperature of 75-85°C; And / or, in step (4), the fifth contact time is 4-9 hours.

8. A polymer comprising structural unit P, structural unit C, and structural unit D, characterized in that, The structural unit P is structural unit A with the structure shown in equation (1) and / or structural unit B with the structure shown in equation (2), the structural unit C is structural unit with the structure shown in equation (3), and the structural unit D is structural unit with the structure shown in equation (4). Equation (1); Equation (2); Equation (3); Equation (4); In this configuration, R1 and R2 are each independently H or methyl, M1 is H or an alkali metal, and R3 is C6-C. 18 Alkyl groups; 7 ≤ n ≤ 19.

9. The polymer according to claim 8, wherein, M1 is H, sodium, or potassium; And / or, R1 is H, R2 is H, R3 is octyl, M1 is Na, and n is 15; Alternatively, R1 is H, R2 is H, R3 is nonyl, M1 is Na, and n is 9; Alternatively, R1 is H, R2 is H, R3 is dodecyl, M1 is Na, and n is 7; Alternatively, R1 is H, R2 is methyl, R3 is tetradecyl, M1 is H, and n is 7; Alternatively, R1 is H, R2 is H, R3 is hexadecyl, M1 is Na, and n is 15.

10. The polymer according to claim 8 or 9, wherein, Based on the total weight of the polymer, the content of the structural unit P is 85-99% by weight. And / or, the content of structural unit B accounts for 10-35% by weight of the content of structural unit P. And / or, the total content of structural unit C and structural unit D is 1-15% by weight. And / or, the structural unit C accounts for 10-90% by weight of the total content of structural units C and D. And / or, the structural unit D accounts for 10-90% by weight of the total content of structural unit C and structural unit D. And / or, the weight ratio of the structural unit P, the structural unit C, and the structural unit D is 1:(0.01-0.1):(0.01-0.1).

11. The polymer according to claim 10, wherein, Based on the total weight of the polymer, the content of the structural unit P is 90-98% by weight. And / or, the content of structural unit B accounts for 12-30% by weight of the content of structural unit P. And / or, the total content of structural unit C and structural unit D is 2-10% by weight%. And / or, the structural unit C accounts for 15-85% by weight of the total content of structural units C and D. And / or, the structural unit D accounts for 15-85% by weight of the total content of structural unit C and structural unit D.

12. A method for preparing a polymer, characterized in that, The method includes: under solution polymerization conditions, in the presence of an initiator, causing the monomer to undergo a polymerization reaction to obtain a copolymer colloid; hydrolyzing or not hydrolyzing the copolymer colloid; the monomer includes monomer P', monomer C' as shown in formula (7), monomer D' as shown in formula (8), and monomer P' is monomer A' as shown in formula (5) and / or monomer B' as shown in formula (6); Equation (5); Equation (6); Equation (7); Equation (8); Wherein, R1 and R2 are H or methyl; M1 is H or an alkali metal; R3 is C6-C 18 Alkyl group; 7 ≤ n ≤ 19.

13. The method according to claim 12, wherein, M1 is H, sodium, or potassium; And / or, R1 is H, R2 is H, R3 is octyl, M1 is Na, and n is 15; Alternatively, R1 is H, R2 is H, R3 is nonyl, M1 is Na, and n is 9; Alternatively, R1 is H, R2 is H, R3 is dodecyl, M1 is Na, and n is 7; Alternatively, R1 is H, R2 is methyl, R3 is tetradecyl, M1 is H, and n is 7; Alternatively, R1 is H, R2 is H, R3 is hexadecyl, M1 is Na, and n is 15.

14. The method according to claim 12, wherein, Based on the total weight of the monomers, the amount of monomer P' is 85-99% by weight. And / or, the total amount of said monomer C' and monomer D' is 1-15% by weight. And / or, the monomer C' accounts for 10-90% by weight of the total amount of monomer C' and monomer D'. And / or, the monomer D' accounts for 10-90% by weight of the total amount of monomer C' and monomer D'.

15. The method according to claim 14, wherein, The monomer P' is monomer A' as shown in formula (5) and monomer B' as shown in formula (6), and the mass of monomer B' accounts for 10-35% of the amount of monomer P' used.

16. The method of claim 14, wherein, Based on the total weight of the monomers, the amount of monomer P' is 90-98% by weight. And / or, the total amount of monomer C' and monomer D' is 2-10% by weight. And / or, the monomer C' accounts for 15-85% by weight of the total amount of monomer C' and monomer D'. And / or, the monomer D' accounts for 15-85% by weight of the total amount of monomer C' and monomer D'.

17. The method according to claim 15, wherein, The monomer P' is monomer A' as shown in formula (5) and monomer B' as shown in formula (6), and the mass of monomer B' accounts for 12-30% of the amount of monomer P' used.

18. The method according to claim 12, wherein, The initiator is at least one of azo initiators, redox initiators, and photoinitiators; And / or, the amount of the initiator is 0.0001-0.3% by weight of the total weight of the monomer.

19. The method according to claim 18, wherein, The amount of the azo initiator is 0.0001-0.1% of the total weight of the monomers.

20. The method according to claim 18, wherein, The amount of the redox initiator is 0.0002-0.3% of the total weight of the monomer.

21. The method according to claim 19, wherein, The azo initiator is a water-soluble azo initiator.

22. The method according to claim 21, wherein, The water-soluble azo initiator is at least one of 2,2'-azobis(2-amidinylpropane) dihydrochloride, 2,2'-azobis(2-imidazolinepropane) dihydrochloride, and 4,4'-azobis(4-cyanopentanoic acid).

23. The method according to claim 20, wherein, The redox initiator includes an oxidant and a reducing agent.

24. The method according to claim 23, wherein, The reducing agent is at least one of inorganic reducing agents and organic reducing agents.

25. The method according to claim 23, wherein, The mass ratio of the oxidant to the reducing agent is (0.1-1):

1.

26. The method according to claim 24, wherein, The inorganic reducing agent is at least one of ferrous sulfate, ferrous ammonium sulfate, cuprous chloride, potassium sulfite, sodium sulfite, ammonium bisulfite, potassium bisulfite, sodium thiosulfate, potassium thiosulfate, and sodium bisulfite.

27. The method according to claim 24, wherein, The organic reducing agent is at least one of N,N-dimethylethanolamine, N,N'-dimethylpiperazine, N,N,N',N'-tetramethylurea and N,N,N',N'-tetramethylethylenediamine.

28. The method according to claim 25, wherein, The oxidant is at least one of benzoyl peroxide, hydrogen peroxide, tert-butyl hydroperoxide, 2,5-dimethyl-2,5-bis(hydrogen peroxide)hexane, ammonium persulfate, sodium persulfate, and potassium persulfate.

29. The method according to claim 18, wherein, The photoinitiator is at least one of 2-hydroxy-2,2-dimethylacetophenone and 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylacetophenone.

30. The method according to claim 23, wherein, The redox initiator is a persulfate oxidant and a sulfite reducing agent.

31. The method according to claim 30, wherein, The persulfate oxidant is potassium persulfate and / or ammonium persulfate; And / or, the sulfite reducing agent is potassium bisulfite and / or sodium bisulfite; And / or, relative to 100 parts by weight of the monomer, the persulfate oxidant is 0.01-0.1 parts by weight; And / or, relative to 100 parts by weight of the monomer, the sulfite reducing agent is 0.005-0.05 parts by weight.

32. The method according to any one of claims 12-31, wherein, The conditions for the hydrolysis reaction include: a temperature of 70-90℃ and a time of 2-24 hours.

33. The method according to claim 32, wherein, The hydrolysis reaction is carried out under alkaline conditions.

34. The method according to claim 33, wherein, The alkaline conditions are achieved through alkaline substances.

35. The method according to claim 34, wherein, The alkaline substance is sodium hydroxide and / or potassium hydroxide.

36. The method according to claim 34, wherein, The conditions for the solution polymerization reaction include: temperature of 0-30℃; time of 4-10h; and pH value of 5-12. And / or, the conditions for the solution polymerization reaction further include: being carried out under an inert atmosphere.

37. The method according to claim 36, wherein, The conditions for the solution polymerization reaction include a temperature of 0-25℃.

38. The method according to claim 12, wherein, The conditions for the solution polymerization reaction also include: being carried out in the presence of a complexing agent.

39. The method according to claim 38, wherein, The complexing agent is at least one of EDTA-2Na, sodium triacetate, and diethylenetriaminepentacarboxylate.

40. The method according to claim 39, wherein, The amount of the complexing agent is 0.01-0.1% by weight of the total weight of the monomers. And / or, the method further includes: granulating the copolymer colloid before or without hydrolysis; And / or, the method further includes: pulverizing and sieving the copolymer colloid after hydrolysis or without hydrolysis.

41. The method according to claim 40, wherein, The amount of the complexing agent is 0.02-0.05% of the total weight of the monomers.

42. A polymer prepared by the preparation method according to any one of claims 12-41.

43. The use of the polymer according to any one of claims 8-11 and 42 in oil displacement.

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