Compound, polymer with oil displacement function and preparation method and application thereof

Abstract

This invention relates to the field of petroleum extraction technology, and discloses a compound, a polymer with oil displacement function, its preparation method, and its application. The compound of this invention has the structure shown in formula (8); the polymer of this invention has good solubility at 20-95℃ and a salinity of 500-50000 mg / L, exhibits good viscosity-enhancing effect on the aqueous phase at high temperatures, can improve the mobility ratio, effectively expand the swept volume, and has good temperature resistance. Simultaneously, it can emulsify and disperse crude oil, reduce interfacial tension, and can be used for polymer flooding to improve oil recovery in conventional reservoirs, high-temperature and high-salinity reservoirs, and ordinary heavy oil reservoirs.

Description

Compounds, polymers with oil displacement function, their preparation methods and applications Technical Field

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

[0002] Heavy oil development methods include thermal recovery and cold recovery. Currently, the waterflood recovery rate of heavy oil is only 5-30%, significantly lower than that of light oil. Emulsification viscosity reduction is one of the main methods to improve the recovery rate of heavy oil waterflooding. Currently used viscosity reducers for heavy oil are mainly small molecule surfactants, which are prone to fingering during underground migration, resulting in a small effective swept volume. Polymer and viscosity reducer compound systems have a significant effect on improving the recovery rate, but the chemical agents in the compound system undergo chromatographic separation during formation migration, making it difficult to fully realize the synergistic effect.

[0003] Traditional acrylamide polymers can increase the viscosity of displacement fluids, but they cannot interact with heavy oils and therefore do not have a viscosity-reducing effect. Existing technologies include copolymerizing acrylamide with diisodecyl polyoxyethylene ether maleate diester and aromatic polyoxyethylene ether acrylate to obtain polymeric surfactants. While these surfactants have a viscosity-reducing effect and a certain viscosity, their active monomers are acrylate monomers, which undergo severe hydrolysis at temperatures above 70°C, rendering them unusable.

[0004] Developing a polymer that exhibits good viscosity enhancement in the aqueous phase under high temperature and high salinity conditions, along with good surface and interfacial activity, can improve the oil-water mobility ratio, emulsify and disperse crude oil, reduce interfacial tension, and enhance oil displacement through synergistic effects. This is of great significance for improving oil recovery. Summary of the Invention

[0005] The purpose of this invention is to overcome the aforementioned problems in the prior art and provide a compound and its preparation method, a polymer with oil displacement function and its preparation method and application. This compound simultaneously possesses hydrophilic polyoxyethylene ether, lipophilic long-chain alkane, and benzene ring groups. The interfacial activity can be controlled by adjusting the lengths of the hydrophilic and lipophilic segments. Furthermore, the benzene ring groups of the compound can undergo π-π interactions with heavy oil molecules, emulsifying and dispersing ordinary heavy oil (50-1000 mPa·s), exhibiting excellent crude oil dispersion ability and improving oil displacement efficiency. When the compound of this invention is copolymerized with acrylamide monomer and long-chain monomers containing sulfonic acid groups, the resulting polymer exhibits good solubility at 20-95℃ and a salinity of 500-50000 mg / L. It also shows good viscosity-enhancing effect in the aqueous phase at high temperatures, improving the mobility ratio, effectively expanding the swept volume, exhibiting high viscosity retention over aging, and good temperature resistance. Simultaneously, it can emulsify and disperse crude oil, reducing interfacial tension, and can be used for polymer flooding to enhance oil recovery in conventional reservoirs, high-temperature and high-salinity reservoirs, and ordinary heavy oil reservoirs.

[0006] To achieve the above objectives, a first aspect of the present invention provides a compound having the structure shown in formula (8):

[0007]

[0008] Where R5 is H or methyl, 1≤n1≤12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12); 1≤n2≤19 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19).

[0009] A second aspect of the present invention provides a method for preparing a compound, the method comprising the following steps:

[0010] (1) Under alkylation reaction conditions, glycol compounds are sequentially reacted with sodium hydride and brominated alkanes in the first and second contacts to obtain structures such as HO-(CH2-CH2-O). n1 -(CH2) n2 -CH3 intermediate 1;

[0011] (2) Under chlorination reaction conditions, the intermediate 1 is subjected to a third contact with thionyl chloride to obtain a structure with the following formula: Cl-(CH2-CH2-O) n1 -(CH2) n2 -CH3 intermediate 2;

[0012] (4) Under etherification reaction conditions, the intermediate 2 is brought into a fourth contact with an acrylonitrile-based substance;

[0013] The acryloylaniline substance is 4-hydroxy-2-methylacryloylaniline or 4-hydroxy-2-acryloylaniline;

[0014] Preferably, the glycol compound is at least one selected from ethylene glycol, propylene glycol, diethylene glycol, 1,2-butanediol, 2,3-butanediol, triethylene glycol, tetraethylene triethylene glycol, pentaethylene glycol, hexaethylene glycol, octaethylene glycol, and dodecaethylene glycol.

[0015] Preferably, the brominated alkane is at least one selected from bromoethane, bromopropane, 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.

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

[0017]

[0018] In this configuration, R1, R2, and R3 are each independently H or methyl, M1 and M2 are each independently H or alkali metal, and R4 is C8-C. 18 Alkyl group, R5 is H or methyl, 1≤n1≤12 (e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12); 1≤n2≤19 (e.g. 1, 2, 3, 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:

[0020] Under solution polymerization conditions, in the presence of an initiator, the monomers undergo polymerization to obtain a copolymer colloid; the copolymer colloid is then hydrolyzed, with or without hydrolysis; the monomers include monomer Q', monomer C' as shown in formula (7), monomer D' as shown in formula (8), and monomer Q' is monomer A' as shown in formula (5) and / or monomer B' as shown in formula (6);

[0021]

[0022]

[0023] In this configuration, R1, R2, and R3 are each independently H or methyl, M1 and M2 are each independently H or alkali metal, and R4 is C8-C. 18 The alkyl group, R5 being H or methyl, 1≤n1≤12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12); 1≤n2≤19 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19). A fifth aspect of the invention provides a polymer prepared by the preparation method described above.

[0024] The sixth aspect of the present invention provides the use of the polymer as described above in polymer flooding for oil displacement.

[0025] The beneficial effects of the present invention through the above technical solution include:

[0026] (1) The compound of the present invention has a hydrophilic polyoxyethylene ether long chain, a lipophilic alkyl long chain, and a benzene ring group. The interfacial activity can be controlled by adjusting the length of the polyoxyethylene ether segment and the alkyl long chain segment.

[0027] (2) The polymer prepared by the preparation method of the present invention (preferably by free radical aqueous solution) has the functions of water phase thickening and emulsifying and dispersing crude oil. On the one hand, the polymer contains long-chain alkane sulfonic acid groups with large side groups, which enhances the rigidity of the polymer chain. At the same time, its steric hindrance can effectively resist the compression of the polymer chain under high temperature and high salinity, enhance the temperature and salt resistance, inhibit hydrolysis at high temperature, and have good long-term aging stability. On the other hand, the polymer introduces structural units containing polyoxyethylene ether and long-chain alkanes with emulsifying and dispersing crude oil and controllable interfacial activity, which can emulsify and disperse crude oil, reduce oil-water interfacial tension, and improve oil displacement efficiency.

[0028] (3) The polymer of the present invention has good solubility at 20-95℃ and a salinity of 500-50000mg / L. It has good viscosity-enhancing effect on the aqueous phase at high temperature, can improve the mobility ratio, effectively expand the swept volume, and can emulsify and disperse crude oil, reduce interfacial tension. It can be used for polymer flooding to improve the recovery rate in conventional oil reservoirs, high-temperature and high-salinity oil reservoirs and ordinary heavy oil reservoirs. Detailed Implementation

[0029] 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.

[0030] The first aspect of the present invention provides a compound having the structure shown in formula (8):

[0031]

[0032] Where R5 is H or methyl, 1≤n1≤12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12); 1≤n2≤19 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19).

[0033] In this invention, n1 and n2 are both integers.

[0034] A second aspect of the present invention provides a method for preparing a compound, the method comprising the following steps:

[0035] (1) Under alkylation reaction conditions, glycol compounds are sequentially reacted with sodium hydride and brominated alkanes in the first and second contacts to obtain structures such as HO-(CH2-CH2-O). n1 -(CH2) n2 -CH3 intermediate 1;

[0036] (2) Under chlorination reaction conditions, the intermediate 1 is subjected to a third contact with thionyl chloride to obtain a structure with the following formula: Cl-(CH2-CH2-O) n1 -(CH2) n2 -CH3 intermediate 2;

[0037] (3) Under etherification reaction conditions, the intermediate 2 is brought into a fourth contact with an acrylonitrile-like substance;

[0038] The acryloylaniline substance is 4-hydroxy-2-methylacryloylaniline or 4-hydroxy-2-acryloylaniline;

[0039] Preferably, the glycol compound is at least one selected from ethylene glycol, propylene glycol, diethylene glycol, 1,2-butanediol, 2,3-butanediol, triethylene glycol, tetraethylene triethylene glycol, pentaethylene glycol, hexaethylene glycol, octaethylene glycol, and dodecaethylene glycol.

[0040] Preferably, the brominated alkane is at least one selected from bromoethane, bromopropane, 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.

[0041] In this invention, 1≤n1≤12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12); 1≤n2≤19 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19).

[0042] In this invention, n1 and n2 are both integers.

[0043] In this invention, there is no particular limitation on the amount of each raw material used in the preparation process of the compound.

[0044] In some embodiments of the present invention, the amount of sodium hydride used is 1-1.5 mol relative to 1 mol of glycol compound.

[0045] In some embodiments of the present invention, the amount of the bromoalkane is 0.8-1.5 mol relative to 1 mol of glycol compound, preferably 0.9-1.3 mol.

[0046] In some embodiments of the present invention, the amount of thionyl chloride used is 1.2-2.5 mol relative to 1 mol of intermediate 1, preferably 1.3-2 mol.

[0047] In some embodiments of the present invention, the amount of the acryloylaniline substance used relative to 1 mol of intermediate 2 is 0.6-1 mol, preferably 0.7-0.9 mol. In some embodiments of the present invention, in step (1), the alkylation reaction conditions include: a reaction temperature of 10-40°C, preferably 15-25°C.

[0048] In some embodiments of the present invention, in step (1), the first contact time is 20-60 min, preferably 25-45 min.

[0049] In some embodiments of the present invention, in step (1), the second contact time is 2-4 hours, preferably 2-3 hours.

[0050] In some embodiments of the present invention, the first contact is carried out in an organic solvent, preferably selected from tetrahydrofuran and / or ethylene glycol dimethyl ether. The amount of the organic solvent used is not particularly limited, as long as it is sufficient to dissolve glycol compounds.

[0051] In some embodiments of the present invention, step (1) includes: dissolving a glycol compound in an organic solvent, adding sodium hydride thereto, and conducting a first contact under alkylation reaction conditions. Preferably, to prevent the release of hydrogen gas during the first contact reaction from being too vigorous, the sodium hydride may be added in multiple portions, such as 3-5 times. There is no particular limitation on the amount added each time, as long as the reaction process during the first contact is prevented from being too vigorous.

[0052] In some embodiments of the present invention, step (1) includes adding a brominated alkane to the reaction system after the first contact. It should be understood that, to avoid an overly vigorous reaction, the brominated alkane is added slowly to the reaction system after the first contact, and those skilled in the art can control the addition rate of the brominated alkane according to the actual situation. Preferably, the addition rate of the brominated alkane is 10-20 mmol / min relative to 100 mmol of glycol compounds.

[0053] 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).

[0054] In some embodiments of the present invention, in step (2), the chlorination reaction conditions include: a reaction temperature of 60-85°C, preferably 70-80°C.

[0055] In some embodiments of the present invention, in step (2), the third contact time is 8-12 hours, preferably 10-11 hours.

[0056] In some embodiments of the present invention, step (2) includes adding thionyl chloride to the reaction system obtained in step (1). It should be understood that, to avoid an overly vigorous reaction, thionyl chloride is added slowly dropwise to the reaction system after the first contact. Those skilled in the art can control the addition rate of the thionyl chloride according to the actual situation. Preferably, the addition rate of the thionyl chloride is 50-200 mmol / min relative to 1 mol of intermediate 1.

[0057] In some embodiments of the present invention, in order to improve the reaction yield and neutralize the hydrogen chloride generated during the third contact process (i.e., when thionyl chloride reacts with intermediate 1 in a chlorination reaction), 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 intermediate 2. Preferably, the amount of pyridine used is 1-3 mol relative to 1 mol of intermediate 1.

[0058] 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.

[0059] In some embodiments of the present invention, in step (3), the etherification reaction conditions include: a reaction temperature of 60-90°C, preferably 75-85°C.

[0060] In some embodiments of the present invention, in step (3), the fourth contact time is 5-10 hours, preferably 6-8 hours.

[0061] In some embodiments of the present invention, the acryloylaniline substance undergoes a fourth contact with intermediate 2 in the form of a solution. The solvent for the acryloylaniline substance solution can be a commonly used organic solvent in the art, such as tetrahydrofuran. The amount of the organic solvent is not particularly limited, as long as it is sufficient to dissolve the acryloylaniline substance. Preferably, to promote the etherification reaction between the phenolic hydroxyl group in the acryloylaniline substance and intermediate 2, and to neutralize the hydrogen halide produced in the reaction, the acryloylaniline substance solution also contains potassium carbonate. The amount of potassium carbonate is 1.2-2 mol relative to 1 mol of acryloylaniline substance.

[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 based on actual conditions, and this will not be elaborated further. In some embodiments of the present invention, step (3) further includes purification after the fourth contact. The purification methods are 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: 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 (preferably 75 mL × 3) 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.

[0063] In some embodiments of the present invention, the first contact, the second contact, the third contact, and the fourth contact are carried out in an organic solvent, preferably, the organic solvent is selected from tetrahydrofuran and / or ethylene glycol dimethyl ether.

[0064] The third aspect of the present invention provides a polymer with oil displacement function, the polymer containing structural unit Q, structural unit C and structural unit D, wherein structural unit Q is structural unit A having the structure shown in formula (1) and / or structural unit B having the structure shown in formula (2), structural unit C is structural unit having the structure shown in formula (3), and structural unit D is structural unit having the structure shown in formula (4).

[0065]

[0066] In this configuration, R1, R2, and R3 are each independently H or methyl, M1 and M2 are each independently H or alkali metal, and R4 is C8-C. 18 Alkyl groups (especially straight-chain alkyl groups) of C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, and C18, where R5 is H or methyl, and 1 ≤ n1 ≤ 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12); 1 ≤ n2 ≤ 19 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, and 19).

[0067] In this invention, n1 and n2 are both integers.

[0068] In some embodiments of the present invention, the alkali metal is Na and / or K.

[0069] In some embodiments of the present invention, R1 is H, R2 is H, R3 is H, M1 is Na, M2 is H, R4 is dodecyl, R5 is H, n1 = 1, and n2 = 15.

[0070] In some embodiments of the present invention, R1 is H, R2 is H, R3 is H, M1 is Na, M2 is H, R4 is tetradecyl, R5 is H, n1 = 5, and n2 = 9.

[0071] In some embodiments of the present invention, R1 is H, R2 is H, R3 is H, M1 is Na, M2 is H, R4 is hexadecyl, R5 is CH3, n1 = 12, and n2 = 2.

[0072] In some embodiments of the present invention, R1 is H, R2 is H, R3 is H, M1 is Na, M2 is H, R4 is hexadecyl, R5 is H, n1 = 5, and n2 = 9.

[0073] In some embodiments of the present invention, R1 is H, R2 is CH3, R3 is H, M1 is H, M2 is H, R4 is hexadecyl, R5 is H, n1 = 5, and n2 = 9.

[0074] In some embodiments of the present invention, the content of the structural unit Q is 80-98% by weight, based on the total weight of the polymer. For example, it can be any one of 80% by weight, 81% by weight, 82% by weight, 83% by weight, 84% by weight, 85% by weight, 86% by weight, 87% by weight, 88% by weight, 89% by weight, 90% by weight, 91% by weight, 92% by weight, 93% by weight, 94% by weight, 95% by weight, 96% by weight, 97% by weight, or a value within a range of any two of the above values. Preferably, the content of the structural unit Q is 85-95% by weight, based on the total weight of the polymer.

[0075] In some embodiments of the present invention, the content of structural unit B accounts for 6-35% by weight of the content of structural unit Q, for example, it can be any one of 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, 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 9-30% by weight of the content of structural unit Q.

[0076] 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 2-20% by weight, for example, it can be any one of 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, 15% by weight, 16% by weight, 17% by weight, 18% by weight, 19% by weight, and 20% 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 5-15% by weight.

[0077] In some embodiments of the present invention, the structural unit C accounts for 20-50% by weight of the total content of the structural units C and D. For example, it can be any one of 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, 35% by weight, 36% by weight, 37% by weight, 38% by weight, 39% by weight, 40% by weight, 41% by weight, 42% by weight, 43% by weight, 44% by weight, 45% by weight, 46% by weight, 47% by weight, 48% by weight, 49% by weight, or 50% by weight. Preferably, the structural unit C accounts for 25-45% by weight of the total content of the structural units C and D.

[0078] In some embodiments of the present invention, the structural unit D accounts for 50-80% by weight of the total content of the structural unit C and the structural unit D. For example, it can be any one of 50% by weight, 51% by weight, 52% by weight, 53% by weight, 54% by weight, 55% by weight, 56% by weight, 57% by weight, 58% by weight, 59% by weight, 60% by weight, 61% by weight, 62% by weight, 63% by weight, 64% by weight, 65% by weight, 66% by weight, 67% by weight, 68% by weight, 69% by weight, 70% by weight, 71% by weight, 72% by weight, 73% by weight, 74% by weight, 75% by weight, 76% by weight, 77% by weight, 78% by weight, 79% by weight, and 80% by weight, or a value within a range of any two of the above values. Preferably, the structural unit D accounts for 55-75% by weight of the total content of the structural unit C and the structural unit D.

[0079] In some embodiments of the present invention, the polymer has a viscosity-average molecular weight of 5 million to 12 million.

[0080] 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, the content of each unreacted monomer in the polymer is found to be below 0.05% by weight, indicating that almost all monomers participate in the polymerization reaction. Specifically, the content of the residual monomers is determined using liquid chromatography.

[0081] A fourth aspect of the present invention provides a method for preparing a polymer, the method comprising:

[0082] Under solution polymerization conditions, in the presence of an initiator, the monomers are polymerized to obtain a copolymer colloid; the copolymer colloid is then hydrolyzed, with or without hydrolysis; the monomers include monomer Q', monomer C' as shown in formula (7), and monomer D' as shown in formula (8), wherein monomer Q' is monomer A' as shown in formula (5) and / or monomer B' as shown in formula (6);

[0083]

[0084] In this configuration, R1, R2, and R3 are each independently H or methyl, M1 and M2 are each independently H or alkali metal, and R4 is C8-C. 18 Alkyl groups (especially straight-chain alkyl groups) of C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, and C18, where R5 is H or methyl, and 1 ≤ n1 ≤ 12 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12); 1 ≤ n2 ≤ 19 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, and 19).

[0085] In this invention, n1 and n2 are both integers.

[0086] In some embodiments of the present invention, the alkali metal is Na and / or K.

[0087] In some embodiments of the present invention, R1 is H, R2 is H, R3 is H, M1 is Na, M2 is H, R4 is dodecyl, R5 is H, n1 = 1, and n2 = 15.

[0088] In some embodiments of the present invention, R1 is H, R2 is H, R3 is H, M1 is Na, M2 is H, R4 is tetradecyl, R5 is H, n1 = 5, and n2 = 9.

[0089] In some embodiments of the present invention, R1 is H, R2 is H, R3 is H, M1 is Na, M2 is H, R4 is hexadecyl, R5 is CH3, n1 = 12, and n2 = 2.

[0090] In some embodiments of the present invention, R1 is H, R2 is H, R3 is H, M1 is Na, M2 is H, R4 is hexadecyl, R5 is H, n1 = 5, and n2 = 9.

[0091] In some embodiments of the present invention, R1 is H, R2 is CH3, R3 is H, M1 is H, M2 is H, R4 is hexadecyl, R5 is H, n1 = 5, and n2 = 9.

[0092] In some embodiments of the present invention, based on the total weight of the monomers, the amount of monomer Q' is 80-98% by weight, for example, it can be any one of 80% by weight, 81% by weight, 82% by weight, 83% by weight, 84% by weight, 85% by weight, 86% by weight, 87% by weight, 88% by weight, 89% by weight, 90% by weight, 91% by weight, 92% by weight, 93% by weight, 94% by weight, 95% by weight, 96% by weight, 97% by weight, 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 Q' is 85-95% by weight.

[0093] In some embodiments of the present invention, the amount of monomer B' accounts for 6-35% by weight of the amount of monomer Q', for example, it can be any one of 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, 30 wt%, 31 wt%, 32 wt%, 33 wt%, 34 wt%, 35 wt%, or a value within a range of any two of the above values. Preferably, the amount of monomer B' accounts for 9-30% by weight of the amount of monomer Q'.

[0094] 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 2-20% by weight, for example, it can be any one of 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, and 20% 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 5-15% by weight.

[0095] In some embodiments of the present invention, the amount of monomer C' is 20-50% by weight of the total amount of monomer C' and monomer D', for example, it can be any one of 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, 35% by weight, 36% by weight, 37% by weight, 38% by weight, 39% by weight, 40% by weight, 41% by weight, 42% by weight, 43% by weight, 44% by weight, 45% by weight, 46% by weight, 47% by weight, 48% by weight, 49% by weight, or a value within a range of any two of the above values. Preferably, the amount of monomer C' is 25-45% by weight of the total amount of monomer C' and monomer D'.

[0096] In some embodiments of the present invention, the amount of monomer D' accounts for 50-80% by weight of the total amount of monomer C' and monomer D'. For example, it can be any one of 50% by weight, 51% by weight, 52% by weight, 53% by weight, 54% by weight, 55% by weight, 56% by weight, 57% by weight, 58% by weight, 59% by weight, 60% by weight, 61% by weight, 62% by weight, 63% by weight, 64% by weight, 65% by weight, 66% by weight, 67% by weight, 68% by weight, 69% by weight, 70% by weight, 71% by weight, 72% by weight, 73% by weight, 74% by weight, 75% by weight, 76% by weight, 77% by weight, 78% by weight, 79% by weight, and 80% by weight, or a value within a range of any two of the above values. Preferably, the amount of monomer D' accounts for 55-75% by weight of the total amount of monomer C' and monomer D'.

[0097] 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.

[0098] 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 80-98% by weight, preferably 85-95% by weight; based on the total weight of the monomers, the total amount of monomer C' and monomer D' is 2-20% by weight, preferably 5-15% by weight; monomer C' accounts for 20-50% by weight of the total amount of monomer C' and monomer D', preferably 25-45% by weight; and monomer D' accounts for 50-80% by weight of the total amount of monomer C' and monomer D', preferably 55-75% by weight.

[0099] In some preferred embodiments of the present invention, the monomers include monomer Q', monomer C' as shown in formula (7), and monomer D' as shown in formula (8), wherein monomer Q' is monomer A' as shown in formula (5) and monomer B' as shown in formula (6). Based on the total weight of the monomers, the amount of monomer Q' is 80-98% by weight, preferably 85-95% by weight; the amount of monomer B' is 6-35% by weight, preferably 9-30% by weight; and the amount of monomer A' is 65-94% by weight, preferably 70-91% by weight. Based on the total weight of the monomers, the total amount of monomer C' and monomer D' is 2-20% by weight, preferably 5-15% by weight; monomer C' is 20-50% by weight, preferably 25-45% by weight; and monomer D' is 50-80% by weight, preferably 55-75% by weight.

[0100] 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 15-40% by weight.

[0101] 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 adjusting the pH of the monomer solution to 5-12.

[0102] In this invention, the polymerization reaction is initiated by at least one of photoinitiation, thermal initiation, radiation initiation, and initiation by adding an initiator.

[0103] 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.

[0104] In some embodiments of the present invention, the initiator is at least one of an azo initiator, a redox initiator, and a photoinitiator.

[0105] 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 monomers.

[0106] 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.

[0107] 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 monomer.

[0108] In some embodiments of the present invention, the azo initiator is a water-soluble azo initiator.

[0109] 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).

[0110] In some embodiments of the present invention, the redox initiator includes an oxidant and a reducing agent;

[0111] In some embodiments of the present invention, the reducing agent is at least one of inorganic reducing agents and organic reducing agents.

[0112] In some embodiments of the present invention, the mass ratio of the oxidant to the reducing agent is (0.1-1):1.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] In some embodiments of the present invention, the redox initiator is a persulfate oxidant and a sulfite reductant. Preferably, relative to 100 parts by weight of the monomer, the persulfate oxidant is 0.01-0.1 parts by weight, and the sulfite reductant is 0.005-0.05 parts by weight. More preferably, the persulfate oxidant is potassium persulfate and / or ammonium persulfate. More preferably, the sulfite is potassium bisulfite and / or sodium bisulfite.

[0118] In some embodiments of the present invention, the conditions for the hydrolysis reaction include: a temperature of 60-90°C and a time of 2-24 hours, preferably 8-20 hours.

[0119] In some embodiments of the present invention, the hydrolysis reaction can be 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.

[0120] In some embodiments of the present invention, the conditions for the solution polymerization reaction include: a temperature of 0-30°C, a time of 4-10 hours, 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 an alkaline substance like sodium hydroxide or an acidic substance like acrylic acid.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] 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 0.02-0.08% by weight.

[0125] 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.

[0126] In some embodiments of the present invention, the method further includes granulating the copolymer colloid before or without hydrolysis.

[0127] In some embodiments of the present invention, the method further includes: pulverizing and sieving the copolymer colloid after hydrolysis or without hydrolysis.

[0128] In a preferred embodiment of the present invention, the method includes:

[0129] 1) Add monomers C' and D' to deionized water, stir until fully dissolved, and obtain a functional monomer solution;

[0130] 2) Add monomer A' and / or monomer B' to deionized water and stir until homogeneous to obtain monomer Q' solution;

[0131] 3) Add the functional monomer solution to the monomer Q' solution, stir thoroughly, adjust the pH to 5-12, and adjust the temperature to 0℃-30℃ to obtain the monomer solution;

[0132] 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. After the system temperature rises by 0.3-0.5℃, the inert gas is stopped. After sealing, the solution polymerization reaction is carried out for 4-10 hours to obtain the copolymer colloid.

[0133] 5) The colloid is removed and then granulated, hydrolyzed or not hydrolyzed, dried, pulverized and sieved to obtain the polymer.

[0134] A fifth aspect of the present invention provides a polymer prepared by the method described above.

[0135] The sixth aspect of the present invention provides the application of the polymer as described above in polymer flooding for oil displacement.

[0136] In some embodiments of the present invention, the application is an application in oil reservoir development.

[0137] 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.

[0138] In some embodiments of the present invention, the application is as a modulator / depressant.

[0139] This invention introduces a sulfonic acid structure with long-chain alkanes into the macromolecular chain of polyacrylamide, and introduces a structure containing hydrophilic polyoxyethylene ether, hydrophobic long-chain alkanes, and benzene ring groups with controllable surface and interfacial activity. The resulting polymer exhibits both aqueous phase thickening and strong oil dispersing ability under conditions of 20-95℃ and a salinity of 500-50000 mg / L. It can emulsify and disperse crude oil, reduce interfacial tension, and has a high aging viscosity retention rate. It is suitable for use as a modifier in conventional reservoirs, high-temperature and high-salinity reservoirs, and ordinary heavy oil reservoirs.

[0140] The present invention will be described in detail below through embodiments. In the following embodiments,

[0141] Unless otherwise specified, all raw materials are commercially sourced.

[0142] Acrylamide crystals (i.e. monomer A') were purchased from Shandong Nuoer Biotechnology Co., Ltd.

[0143] Sodium acrylate and methacrylic acid (i.e. monomer B') were purchased from Sigma-Aldrich.

[0144] Monomers C1', C2', and C3' were prepared according to Examples 1, 4, and 5 of patent CN105461598B, "Acrylamide Monomers, Acrylamide Copolymers and Their Preparation Methods and Applications." The structure of monomer C1' is shown in formula (7), where R3 is H and R4 is C.12 H 25 M2 is H; the structural formula of monomer C2' is shown in formula (7), R3 is H, and R4 is C. 14 H 29 M2 is H; the structural formula of monomer C3' is shown in formula (7), R3 is H, and R4 is C. 16 H 33 M2 is H.

[0145] The testing method is as follows:

[0146] 1) Determination of residual monomer content

[0147] 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.

[0148] 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.

[0149] 2) Apparent viscosity was measured using a Brookfield viscometer in simulated water at 20°C and 5000 mg / L of mineralization, and in simulated water at 95°C and 30000 mg / L of mineralization.

[0150] 3) The oil dispersibility is determined according to Q / SH1020 1957-2008 "Technical Conditions for Active Polymers for Oil Displacement". The specific method is as follows: ① Add polymer to brine with a salinity of 10000 mg / L to prepare a test solution with a polymer concentration of 1500 mg / L.

[0151] ②According to the ratio of sample solution to crude oil of 3:1, take 30 mL of the test solution and inject it into a clean, dry stoppered graduated test tube. During the injection process, keep the syringe needle below the liquid surface.

[0152] ③ Pour 10 mL of a specific crude oil (viscosity 100 mPa·s) into the above-mentioned stoppered graduated test tube.

[0153] ④ Hold the stoppered graduated test tube firmly with your hand and shake it up and down 50 times. Observe the effect of the sample solution on the crude oil. The crude oil is considered to be completely dispersed as qualified. Record the volume of the mixed solution V1.

[0154] ⑤ Place the stoppered graduated test tube in a 70℃ oven and let it stand for 24 hours. Measure the volume V2 of the precipitated solution. The oil dispersion ability F is calculated as F = (V1 - V2) / V1 × 100%. Perform three parallel determinations and take the average value as the result.

[0155] 4) For interfacial tension testing, refer to the "rotation drop method" in the standard SY / T 5370-2018 "Methods for Determination of Surface and Interfacial Tension" to measure the interfacial tension of the sample at 25℃.

[0156] 5) The viscosity-average molecular weight of the polymer is determined according to 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.

[0157] 6) The aging viscosity retention rate was determined according to Q / SH1020 1957-2008 "Technical Conditions for Active Polymers for Oil Displacement". The determination method is as follows:

[0158] ① A polymer solution with a polymer concentration of 5000 mg / L was prepared by dissolving the polymer in simulated saline with a mineralization of 5727 mg / L and a total calcium and magnesium ion concentration of 108 mg / L. 60 g of the polymer solution with a concentration of 5000 mg / L was added to a 400 mL beaker, and 140 g of simulated saline (mineralization of 5727 mg / L and total calcium and magnesium ion concentration of 108 mg / L) was added. The mixture was stirred on a magnetic stirrer at a speed of (300±20) r / min to obtain a test solution with a polymer concentration of 1500 mg / L. The apparent viscosity at 70 °C was measured and recorded as η1.

[0159] ② Dispense 180 mL of the test solution into 6 ampoules and connect the ampoules to the evacuation manifold. Freeze the manifold and ampoules together, then place them in a cold trap and connect it to the evacuation device. Evacuate to 13.3 Pa, then thaw at room temperature. Repeat this process twice. Then, purge the manifold and ampoules with nitrogen. Once the ampoule pressure reaches the atmospheric pressure of the day, seal the ampoules with a flame-sealing device and store them in a 70°C oven.

[0160] ③ After 3 months of heat aging, remove the ampoule and measure the apparent viscosity, recording it as η2. Aging viscosity retention rate = η2 / η1 × 100%. η1 is the apparent viscosity of the sample before heat aging, in mPa·s, and η2 is the apparent viscosity of the sample before heat aging, in mPa·s.

[0161] Unless otherwise specified, in the following preparation examples, embodiments and comparative examples, "room temperature" refers to 25°C.

[0162] Preparation Example 1

[0163] This preparation example illustrates monomer D' (compound M1) and its preparation method.

[0164] At 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 allowed to continue for 2 hours. After the reaction was complete, 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).

[0165] 4-Hydroxy-2-acrylanilide (3.264 g, 20 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 naturally to room temperature, and then the reaction system was quenched with water. The pH was then adjusted to 3 with dilute hydrochloric acid solution. The reaction product was extracted with diethyl ether (75 mL × 3). The organic phase was washed three times with saturated sodium chloride, and then dried with Na2SO4. After rotary evaporation, the organic phase was recrystallized (the recrystallization solvent was a mixture of dichloromethane and petroleum ether in a volume ratio of 4:1) to give compound M1 (6.043 g, 14 mmol).

[0166] The reaction process is as follows:

[0167] (1)

[0168]

[0169] (2)

[0170]

[0171] The structural identification results of M1 are as follows:

[0172] 1 H NMR (300MHz, CDCl3) δ: 9.20 (s, 1H), 7.68 (dd, 2H), 6.82 (dd, 2H), 6.48 (t, 1H), 6.07 (dd, 1H), 5.73 (d d,1H),4.30(t,2H),3.76(t,2H),3.34(t,2H),1.45-1.55(m,4H),1.25-1.32(m,24H),0.87(t,3H);

[0173] 13 C NMR (75MHz, CDCl3) δ: 166.6, 154.9, 131.0, 129.0, 126.7, 122.1, 114.5, 70.6, 69.9, 69.2, 31.8, 29.9, 29.5, 29.2, 22.5, 14.0.

[0174] As can be seen from the above results, M1 has the structure shown in equation (8), where R5 is H, n1 = 1, and n2 = 15.

[0175] Preparation Example 2

[0176] The preparation examples illustrate the monomer D' (compound M2) and its preparation method provided by the present invention.

[0177] At 25°C, pentaethylene glycol (23.828 g, 100 mmol) was added, followed by dissolution with 100 mL of anhydrous tetrahydrofuran. After complete dissolution, sodium hydride was added in five portions, totaling 3.12 g. The reaction was allowed to proceed for 30 minutes. Then, bromodecane (25.436 g, 115 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 complete, 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 (17.034 g, 45 mmol). A certain amount of pyridine (6.249 g, 79 mmol) was added, followed by slow dropwise addition of excess SOCl2 (8.565 g, 72 mmol) (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 collected, the pH was adjusted to 8.3, and the mixture was washed 6 times with water. After rotary evaporation and drying, intermediate IM2 (11.909 g, 30 mmol) was obtained.

[0178] 4-Hydroxy-2-acrylanilide (4.080 g, 25 mmol) was dissolved in tetrahydrofuran (200 mL), and potassium carbonate (4.422 g, 32 mmol) was added. After stirring and homogenization, the mixture was heated to 75 °C, and intermediate IM2 (11.909 g, 30 mmol) was added. The mixture was refluxed for 8 hours. After the reaction was completed, the mixture was allowed to cool naturally to room temperature, and then the reaction system was quenched with water. The pH was then adjusted to 3 with dilute hydrochloric acid solution. The reaction product was extracted with diethyl ether (75 mL × 3). The organic phase was washed three times with saturated sodium chloride, and then dried with Na2SO4. After rotary evaporation, the organic phase was recrystallized (the recrystallization solvent was a mixture of dichloromethane and petroleum ether in a volume ratio of 4:1) to give compound M2 (8.379 g, 16 mmol).

[0179] The reaction process is as follows:

[0180] (1)

[0181]

[0182] (2)

[0183] The structural identification results of M2 are as follows:

[0184] 1 H NMR (300MHz, CDCl3) δ: 9.23 (s, 1H), 7.70 (dd, 2H), 6.83 (dd, 2H), 6.49 (t, 1H), 6.09 (dd, 1H), 5.75 (dd, 1H), 4.31(t,2H),3.79(t,2H),3.53(t,16H),3.37(m,2H),1.42-1.52(m,4H),1.23-1.30(m,12H),0.88(t,3H);

[0185] 13 C NMR (75MHz, CDCl3) δ: 166.8, 155.0, 131.2, 129.1, 126.8, 122.4, 114.6, 70.7, 70.1, 69.4, 32.0, 30.1, 29.8, 29.4, 22.8, 14.2.

[0186] As can be seen from the above results, M2 has the structure shown in equation (8), where R5 is H, n1 = 5, and n2 = 9.

[0187] Preparation Example 3

[0188] At 25°C, dodecaethylene glycol (54.665 g, 100 mmol) was added, and 100 mL of anhydrous tetrahydrofuran was added to dissolve it. After complete dissolution, sodium hydride was added in four portions, with a total amount of sodium hydride added being 2.88 g. The reaction was allowed to proceed for 30 minutes, followed by the slow dropwise addition of bromopropane (14.75 g, 120 mmol) (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 bromopropane was removed by vacuum distillation. The mixture was cooled to room temperature to obtain an intermediate (35.52 g, 60 mmol). A certain amount of pyridine (6.960 g, 88 mmol) was added, and excess SOCl2 (11.42 g, 96 mmol) was added dropwise at a slow rate (approximately 7.5 mmol / min). After the addition was complete, the mixture was reacted 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 IM3 (24.29 g, 40 mmol) was obtained.

[0189] 4-Hydroxy-2-methylacrylanilide (5.316 g, 30 mmol) was dissolved in tetrahydrofuran (200 mL), potassium carbonate (6.219 g, 45 mmol) was added, and the mixture was stirred until homogeneous. The mixture was then heated to 75 °C, and intermediate IM1 (24.29 g, 40 mmol) was added. The mixture was refluxed for 8 hours. After the reaction was completed, the mixture was allowed to cool naturally to room temperature, and the reaction system was quenched with water. The pH was then adjusted to 3 with dilute hydrochloric acid solution. The reaction product was extracted with diethyl ether (75 mL × 3). The organic phase was washed three times with saturated sodium chloride, and then dried with Na2SO4. After rotary evaporation, the organic phase was recrystallized (the recrystallization solvent was a mixture of dichloromethane and petroleum ether in a volume ratio of 4:1) to give compound M3 (11.967 g, 16 mmol).

[0190] The reaction process is as follows:

[0191] (1)

[0192]

[0193] (2)

[0194]

[0195] The structural identification of M3 is as follows:

[0196] 1H NMR (300MHz, CDCl3) δ: 9.53 (s, 1H), 7.71 (dd, 2H), 6.86 (dd, 2H), 5.78 (s, 1H), 5.71 (s, 1H), 4 .32(t,2H),3.78(t,2H),3.52(t,44H),3.36(t,2H),1.99(s,3H),1.50(m,2H),0.98(t,3H);

[0197] 13 C NMR (75MHz, CDCl3) δ: 163.9, 155.2, 141.4, 129.3, 122.5, 118.2, 114.5, 71.2, 70.5, 69.4, 27.5, 19.6, 10.3.

[0198] The results above show that M3 has the structure shown in formula (8), where R5 is a methyl group, n1 = 12, and n2 = 2.

[0199] Example 1

[0200] This embodiment is used to illustrate the polymer and its preparation method of the present invention.

[0201] Add 2g of monomer C1' and 3g 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 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, 0.03 g of EDTA-2Na, 1 g of 0.5 wt% aqueous solution of 2,2-azobis(2-amidinepropane) dihydrochloride, 5 g of 0.2 wt% aqueous solution of ammonium persulfate, and 1.5 g of 1.0 wt% aqueous solution of sodium bisulfite were added to the system to initiate polymerization. Nitrogen bubbling was stopped after the system temperature rose by 0.5 °C, and the reaction continued for 4 hours. After polymerization was completed, the resulting colloid was granulated, 5.67 g of sodium hydroxide was added and mixed evenly, and then hydrolyzed at 70 °C for 8 hours. After drying at 60 °C until the solid content reached 89 wt%, the product was pulverized and sieved to obtain the polymer dry powder product, i.e., the polymer.

[0202] 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 69.9% by weight, and the content of structural unit B was 20.1% by weight.

[0203] 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.

[0204] The results of residual monomer A' content, aging viscosity retention rate, oil dispersibility, and interfacial tension of the polymer dry powder products are shown in Table 1. The apparent viscosity of the 2000 mg / L polymer solution in simulated water at 25℃ and 5000 mg / L mineralization, and the apparent viscosity of the 2000 mg / L polymer solution in simulated water at 95℃ and 30000 mg / L mineralization are also shown in Table 1.

[0205] The polymer has a viscosity-average molecular weight of 10.5 million.

[0206] Example 2

[0207] This embodiment illustrates a polymer that emulsifies and disperses crude oil and its preparation method.

[0208] Add 2g of monomer C2' and 4.5g of monomer D' (M2 in Preparation Example 2) to 40g of deionized water, and stir until homogeneous to obtain a functional monomer solution. Take 50g of acrylamide 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 5℃. Nitrogen gas was bubbled into the system for 20 minutes to remove oxygen. Then, 0.03 g of EDTA-2Na, 1 g of 0.5 wt% aqueous solution of 2,2-azobis(2-amidinepropane) dihydrochloride, 5 g of 0.2 wt% aqueous solution of ammonium persulfate, and 1.5 g of 1.0 wt% aqueous solution of sodium bisulfite were added to the system to initiate polymerization. Nitrogen bubbling was stopped after the system temperature was increased by 0.5 °C, and the reaction continued for 4 hours. After polymerization was completed, the resulting colloid was granulated, 4.51 g of sodium hydroxide was added and mixed evenly, and then hydrolyzed at 70 °C for 8 hours. After drying at 60 °C until the solid content reached 89 wt%, the product was pulverized and sieved to obtain the polymer dry powder product.

[0209] The residual monomer A' content, oil dispersibility, and interfacial tension of the obtained polymer dry powder products are shown in Table 1. The apparent viscosity of the 2000 mg / L polymer solution in simulated water at 25℃ and 5000 mg / L mineralization, and the apparent viscosity of the 2000 mg / L polymer solution in simulated water at 95℃ and 30000 mg / L mineralization are also shown in Table 1.

[0210] 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 14.2% by weight.

[0211] 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.

[0212] The polymer has a viscosity-average molecular weight of 11.8 million.

[0213] The results of the apparent viscosity, residual monomer A' content, aging viscosity retention rate, oil dispersibility, and interfacial tension of the polymer dry powder products are shown in Table 1.

[0214] Example 3

[0215] This embodiment illustrates a polymer that emulsifies and disperses crude oil and its preparation method.

[0216] Add 3g of monomer C3' and 6g of monomer D' (M3 in Preparation Example 3) to 50g of deionized water, and stir until homogeneous to obtain a functional monomer solution. Take 81g of acrylamide and add it to 150g of water, add 9.12g of sodium hydroxide, 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 12, and control the initial temperature at 10℃. Nitrogen gas was bubbled into the system for 20 minutes to remove oxygen. Then, 0.03 g of EDTA-2Na, 1 g of 0.5 wt% aqueous solution of 2,2-azobis(2-amidinepropane) dihydrochloride, 5 g of 0.2 wt% aqueous solution of ammonium persulfate, and 1.5 g of 1.0 wt% aqueous solution of sodium bisulfite were added to the system to initiate polymerization. Nitrogen bubbling was stopped after the system temperature was raised by 0.3 °C, and the reaction continued for 4 hours. After polymerization was completed, the resulting colloid was granulated, hydrolyzed at 70 °C for 10 hours, dried at 60 °C until the solid content reached 89 wt%, pulverized, and sieved to obtain the polymer dry powder product.

[0217] 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 72.0% by weight and the content of structural unit B was 18.0% by weight, with the total weight of the polymer as the baseline.

[0218] 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.

[0219] The polymer has a viscosity-average molecular weight of 8.6 million.

[0220] The residual monomer A' content, aging viscosity retention rate, oil dispersibility, and interfacial tension of the obtained polymer dry powder products are shown in Table 1. The apparent viscosity of the 2000 mg / L polymer solution in simulated water at 25℃ and 5000 mg / L mineralization, and the apparent viscosity of the 2000 mg / L polymer solution in simulated water at 95℃ and 30000 mg / L mineralization are also shown in Table 1.

[0221] Example 4

[0222] This embodiment illustrates a polymer that emulsifies and disperses crude oil and its preparation method.

[0223] Add 2g of monomer C3' and 4g of monomer D' (M2 in Preparation Example 2) to 40g of deionized water, and stir until homogeneous to obtain a functional monomer solution. Add 40g of acrylamide and 5g of sodium acrylate to 150g of water, stir until homogeneous, and then add to the functional monomer solution. Add 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 0.03g of EDTA-2Na, 1g of 0.5wt% 2,2-azobis(2-amidinepropane) dihydrochloride aqueous solution, 5g of 0.2wt% ammonium persulfate aqueous solution, and 1.5g of 1.0wt% sodium bisulfite aqueous solution to the system to initiate polymerization. Stop purging nitrogen after the system temperature rises by 0.4℃, 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.

[0224] 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.

[0225] The polymer has a viscosity-average molecular weight of 7.5 million.

[0226] The residual monomer A' content, aging viscosity retention rate, oil dispersibility, and interfacial tension of the obtained polymer dry powder products are shown in Table 1. The apparent viscosity of the 2000 mg / L polymer solution in simulated water at 25℃ and 5000 mg / L mineralization, and the apparent viscosity of the 2000 mg / L polymer solution in simulated water at 95℃ and 30000 mg / L mineralization are also shown in Table 1.

[0227] Example 5

[0228] This embodiment illustrates a polymer that emulsifies and disperses crude oil and its preparation method.

[0229] Add 3g of monomer C3' and 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 58g of acrylamide and 6g 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 0℃. Purge the system with nitrogen for 20min to remove oxygen. Then add 0.05g of EDTA-2Na, 1g of 0.5wt% 2,2-azobis(2-amidinylpropane) dihydrochloride aqueous solution, 5g of 0.2wt% ammonium persulfate aqueous solution, and 1.5g of 1.0wt% sodium bisulfite aqueous solution to the system to initiate polymerization. After the system temperature rises by 0.5℃, 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.

[0230] 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 almost completely converted into structural units.

[0231] The polymer has a viscosity-average molecular weight of 6.8 million.

[0232] The residual monomer A' content, aging viscosity retention rate, oil dispersibility, and interfacial tension of the obtained polymer dry powder products are shown in Table 1. The apparent viscosity of the 2000 mg / L polymer solution in simulated water at 25℃ and 5000 mg / L mineralization, and the apparent viscosity of the 2000 mg / L polymer solution in simulated water at 95℃ and 30000 mg / L mineralization are also shown in Table 1.

[0233] Comparative Example 1

[0234] Similar to Example 1, except that monomer D' is not added.

[0235] 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 21.4% by weight.

[0236] 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.

[0237] The polymer has a viscosity-average molecular weight of 16.5 million.

[0238] The residual monomer A' content, aging viscosity retention rate, oil dispersibility, and interfacial tension of the obtained polymer dry powder products are shown in Table 1. The apparent viscosity of the 2000 mg / L polymer solution in simulated water at 25℃ and 5000 mg / L mineralization, and the apparent viscosity of the 2000 mg / L polymer solution in simulated water at 95℃ and 30000 mg / L mineralization are also shown in Table 1.

[0239] Table 1

[0240]

[0241] As shown in the table above, the polymers obtained in Examples 1-5 have significantly higher aqueous phase viscosities at 25°C and 95°C than those in Comparative Example 1. This indicates that the introduction of rigid sulfonic acid monomers and monomers containing polyoxyethylene ethers and long-chain alkane segments into the polymers enhances the rigidity of the polymer chains. Simultaneously, their steric hindrance effectively resists the compression of the polymer chains under high temperature and high salinity, thus achieving efficient viscosity enhancement in the aqueous phase. Furthermore, Examples 1-5 exhibit significantly higher crude oil dispersion capabilities and lower interfacial tension than the Comparative Example. This demonstrates that the introduction of hydrophilic polyoxyethylene ether segments and hydrophobic long-chain monomers (monomer D') with adjustable interfacial activity enables the polymers of this invention to disperse and emulsify crude oil. The crude oil dispersion capabilities of Examples 1-5 are significantly higher than those of Comparative Example 1, exhibiting excellent interfacial activity.

[0242] 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): Formula (8) where R5 is H or methyl, 1≤n1≤12; 1≤n2≤19.

2. A method for preparing the compound according to claim 1, characterized in that, The method includes the following steps: (1) Under alkylation reaction conditions, glycol compounds are sequentially contacted with sodium hydride and brominated alkane substances in a first contact and a second contact to obtain a structure such as HO-(CH2-CH2-O). n1 -(CH2) n2 (2) Under chlorination reaction conditions, the intermediate 1 is subjected to a third contact with thionyl chloride to obtain a structure with the following formula: Cl-(CH2-CH2-O) n1 -(CH2) n2 -CH3 intermediate 2; (3) Under etherification reaction conditions, the intermediate 2 is subjected to a fourth contact with an acrylonitrile; wherein the acrylonitrile is 4-hydroxy-2-methylacrylonitrile or 4-hydroxy-2-acrylonitrile; wherein the glycol compound is ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, heptaethylene glycol, octaethylene glycol, nonaethylene glycol, decaethylene glycol, undecaethylene glycol and dodecaethylene glycol. At least one of glycols; wherein the brominated alkane is at least one of bromoethane, 1-bromopropane, 1-bromobutane, 1-bromopentane, 1-bromohexane, 1-bromoheptane, 1-bromooctane, 1-bromononane, 1-bromodecane, 1-bromoundecane, 1-bromododecane, 1-bromotridecane, 1-bromotetradecane, 1-bromopentadecane, 1-bromohexadecane, 1-bromoheptadecane, 1-bromooctadecane, 1-bromononadecane, and 1-bromoeicosane.

3. The method according to claim 2, wherein, The amount of sodium hydride used is 1-1.5 mol relative to 1 mol of glycol compound; and / or, the amount of bromoalkane used is 0.8-1.5 mol relative to 1 mol of glycol compound; and / or, the amount of thionyl chloride used is 1.2-2.5 mol relative to 1 mol of intermediate 1; and / or, the amount of acrylonitrile used is 0.6-1 mol relative to 1 mol of intermediate 2.

4. The method according to claim 3, wherein, The amount of sodium hydride used is 1-1.5 mol relative to 1 mol of glycol compound; and / or, the amount of bromoalkane used is 0.9-1.3 mol relative to 1 mol of glycol compound; and / or, the amount of thionyl chloride used is 1.3-2 mol relative to 1 mol of intermediate 1; and / or, the amount of acrylonitrile used is 0.7-0.9 mol relative to 1 mol of intermediate 2.

5. The method according to any one of claims 2-4, wherein, In step (1), the alkylation reaction conditions include a reaction temperature of 10-40℃; and / or, in step (2), the chlorination reaction conditions include a reaction temperature of 60-85℃; and / or, in step (3), the etherification reaction conditions include a reaction temperature of 60-90℃; and / or, in step (1), the first contact time is 20-60 min; and / or, in step (1), the second contact time is 2-4 h; and / or, in step (2), the third contact time is 8-12 h; and / or, in step (3), the fourth contact time is 5-10 h.

6. The method according to claim 5, wherein, In step (1), the alkylation reaction conditions include a reaction temperature of 15-25℃; and / or, in step (2), the chlorination reaction conditions include a reaction temperature of 70-80℃; and / or, in step (3), the etherification reaction conditions include a reaction temperature of 75-85℃; and / or, in step (1), the first contact time is 25-45 min; and / or, in step (1), the second contact time is 2-3 h; and / or, in step (2), the third contact time is 10-11 h; and / or, in step (3), the fourth contact time is 6-8 h.

7. A polymer with oil displacement function, the polymer containing structural unit Q, structural unit C and structural unit D, characterized in that, The structural unit Q is structural unit A with the structure shown in equation (1) and / or structural unit B with the structure shown in equation (2), structural unit C is structural unit with the structure shown in equation (3), and 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, R2, and R3 are each independently H or methyl, M1 and M2 are each independently H or alkali metal, and R4 is C8-C. 18 Alkyl group, R5 is H or methyl, 1≤n1≤12; 1≤n2≤19.

8. The polymer according to claim 7, wherein, The alkali metal is Na and / or K.

9. The polymer according to claim 7, wherein, R1 is H, R2 is H, R3 is H, M1 is Na, M2 is H, R4 is dodecyl, R5 is H, n1=1, n2=15; or, R1 is H, R2 is H, R3 is H, M1 is Na, M2 is H, R4 is tetradecyl, R5 is H, n1=5, n2=9; or, R1 is H, R2 is H, R3 is H, M1 is Na, M2 is H, R4 is hexadecyl, R5 is CH3, n1=12, n2=2; or, R1 is H, R2 is H, R3 is H, M1 is Na, M2 is H, R4 is hexadecyl, R5 is H, n1=5, n2=9; or, R1 is H, R2 is CH3, R3 is H, M1 is H, M2 is H, R4 is hexadecyl, R5 is H, n1=5, n2=9.

10. The polymer according to any one of claims 7-9, wherein, Based on the total weight of the polymer, the content of structural unit Q is 80-98% by weight; and / or, the content of structural unit B accounts for 6-35% by weight of the content of structural unit Q; and / or, based on the total weight of the polymer, the total content of structural unit C and structural unit D is 2-20% by weight; and / or, structural unit C accounts for 20-50% by weight of the total content of structural unit C and structural unit D; and / or, structural unit D accounts for 50-80% by weight of the total content of structural unit C and structural unit D.

11. The polymer according to claim 10, wherein, Based on the total weight of the polymer, the content of structural unit Q is 85-95% by weight; and / or, the content of structural unit B is 9-30% by weight of structural unit Q; and / or, based on the total weight of the polymer, the total content of structural unit C and structural unit D is 5-15% by weight; and / or, structural unit C accounts for 25-45% by weight of the total content of structural unit C and structural unit D; and / or, structural unit D accounts for 55-75% 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 monomers to undergo a polymerization reaction to obtain a copolymer colloid; and then hydrolyzing the copolymer colloid, with or without hydrolysis; wherein the monomers include monomer Q', monomer C' as shown in formula (7), monomer D' as shown in formula (8), and monomer Q' is monomer A' as shown in formula (5) and / or monomer B' as shown in formula (6); Equation (5); Equation (6); Equation (7); Formula (8); wherein R1, R2, and R3 are each independently H or methyl, M1 and M2 are each independently H or alkali metal, and R4 is C8-C 18 Alkyl group, R5 is H or methyl, 1≤n1≤12; 1≤n2≤19.

13. The method according to claim 12, wherein, The alkali metal is Na and / or K.

14. The method according to claim 12, wherein, R1 is H, R2 is H, R3 is H, M1 is Na, M2 is H, R4 is dodecyl, R5 is H, n1=1, n2=15; or, R1 is H, R2 is H, R3 is H, M1 is Na, M2 is H, R4 is tetradecyl, R5 is H, n1=5, n2=9; or, R1 is H, R2 is H, R3 is H, M1 is Na, M2 is H, R4 is hexadecyl, R5 is CH3, n1=12, n2=2; or, R1 is H, R2 is H, R3 is H, M1 is Na, M2 is H, R4 is hexadecyl, R5 is H, n1=5, n2=9; or, R1 is H, R2 is CH3, R3 is H, M1 is H, M2 is H, R4 is hexadecyl, R5 is H, n1=5, n2=9.

15. The method according to any one of claims 12-14, wherein, Based on the total weight of the monomers, the amount of monomer Q' used is 80-98% by weight.

16. The method according to claim 15, wherein, Based on the total weight of the monomers, the amount of monomer Q' used is 85-95% by weight.

17. The method according to claim 15, wherein, The amount of monomer B' is 6-35% by weight of the amount of monomer Q'; and / or, based on the total weight of the monomers, the total amount of monomers C' and D' is 2-20% by weight; and / or, the amount of monomer C' is 20-50% by weight of the total amount of monomers C' and D'; and / or, the amount of monomer D' is 50-80% by weight of the total amount of monomers C' and D''.

18. The method according to claim 17, wherein, Based on the total weight of the monomers, the amount of monomer B' is 9-30% of the amount of monomer Q'; and / or, based on the total weight of the monomers, the total amount of monomers C' and D' is 5-15%; and / or, the amount of monomer C' is 25-45%; and / or, the amount of monomer D' is 55-75%.

19. The method according to claim 12, wherein, The initiator is at least one of an azo initiator, a redox initiator, and a photoinitiator; and / or, the amount of the initiator is 0.0001-0.3% by weight of the total weight of the monomer.

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

21. The method according to claim 19, wherein, The amount of the redox initiator is 0.0002-0.3% of the total weight of the monomer.

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

23. The method according to claim 22, 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).

24. The method according to claim 19, wherein, The redox initiator includes an oxidant and a reducing agent.

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

26. The method according to claim 24, wherein, The mass ratio of the oxidant to the reducing agent is (0.1-1):

1.

27. The method according to claim 24, 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.

28. The method according to claim 25, 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.

29. The method according to claim 25, 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.

30. The method according to claim 19, wherein, The photoinitiator is at least one of 2-hydroxy-2,2-dimethylacetophenone and 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylacetophenone.

31. The method according to claim 24, wherein, The redox initiator is an oxidant and a reducing agent, wherein the oxidant is at least one of ammonium persulfate, sodium persulfate, and potassium persulfate, and the reducing agent is at least one of potassium sulfite, sodium sulfite, ammonium bisulfite, potassium bisulfite, and sodium bisulfite.

32. The method according to claim 31, wherein, The oxidant is 0.01-0.1 parts by weight and the reducing agent is 0.005-0.05 parts by weight relative to 100 parts by weight of the monomer.

33. The method according to claim 12, wherein, The conditions for the hydrolysis reaction include: a temperature of 60-90℃ and a time of 2-24h.

34. The method according to claim 12, wherein, The hydrolysis reaction is carried out under alkaline conditions.

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

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

37. The method according to claim 12, wherein, The conditions for the solution polymerization reaction include: a temperature of 0-30°C, a time of 4-10 h, and a pH value of 5-12; and / or, the conditions for the solution polymerization reaction further include: being carried out under an inert atmosphere; and / or, the conditions for the solution polymerization reaction further include: being carried out in the presence of a complexing agent.

38. The method according to claim 37, wherein, The complexing agent is at least one of EDTA-2Na, sodium triacetate, and diethylenetriaminepentacarboxylate.

39. The method according to claim 37, 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 or without hydrolysis.

40. The method according to claim 39, wherein, The amount of the complexing agent is 0.02-0.08% 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 or without hydrolysis.

41. A polymer prepared by the method according to any one of claims 12-40.

42. The use of the polymer according to any one of claims 7-11 and 41 in polymer flooding for oil displacement.

43. The application according to claim 42, wherein, The application refers to the use of polymers in conventional oil reservoirs, high-temperature and high-salinity oil reservoirs, and ordinary heavy oil reservoirs for polymer flooding.

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