Compounds, methods of making the same, and acrylamide copolymers, methods of making the same, and uses thereof

Abstract

This invention relates to the field of petroleum extraction technology, and discloses a compound and its preparation method, an acrylamide copolymer and its preparation method and application. The compound has the structure shown in formula (1): wherein M is H, sodium, potassium or NH4; 1≤n1≤12, 1≤n2≤19; the compound simultaneously has hydrophilic polyoxyethylene ether and sulfonic acid groups, as well as hydrophobic alkyl long chains, and the interfacial activity can be controlled by adjusting the length of the hydrophilic and hydrophobic segments;

Description

Technical Field

[0001] This invention relates to the field of petroleum extraction technology, specifically to a compound and its preparation method, and an acrylamide copolymer and its preparation method and application. Background Technology

[0002] Chemical flooding is a primary technique for enhancing oil recovery in oil reservoirs, encompassing conventional tertiary oil recovery technologies such as surfactant flooding, polymer flooding, 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 low-to-medium permeability layers. Simultaneously, the shear stress and viscoelasticity of the polymer solution can displace isolated or film-like residual oil, reducing blind residual oil. Surfactant flooding can reduce the interfacial tension between rock, oil, and water, lowering residual oil saturation and improving wash-in efficiency. Binary flooding, combining polymers and surfactants, can improve the oil-water mobility ratio while increasing wash-in efficiency and enhancing oil recovery. However, during formation migration, chromatographic separation exists, making it difficult to fully realize the synergistic effect.

[0003] CN110734526A and CN110511329A use acrylamide and 2-acrylamido-2-methylbenzenesulfonic acid to undergo free radical solution polymerization with diisotridecyl polyoxyethylene ether maleate diester and aromatic polyoxyethylene ether acrylate, respectively, to obtain polymeric surfactants. Although they have a viscosity-reducing effect and a certain viscosity, their active monomers are acrylate monomers, which are severely hydrolyzed at temperatures above 70°C and cannot be used.

[0004] With the full utilization of high-quality resources in Class I and II oil reservoirs, the 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; the high-permeability and high-water-cut reservoir environment after chemical flooding; and the environment of heavy oil reservoirs with low recovery rates. Existing research indicates that existing chemical agents have a limited effect on reducing the heavy oil / water mobility ratio and expanding the swept volume, and their limited functionality no longer meets the needs of oilfield development.

[0005] Therefore, developing functional polymers with certain thickening and interfacial tension reduction properties is of great significance for improving oil recovery. Summary of the Invention

[0006] The purpose of this invention is to overcome the aforementioned problems in the prior art and provide a compound and its preparation method, as well as an acrylamide copolymer, its preparation method, and its applications. This compound simultaneously possesses hydrophilic polyoxyethylene ether and sulfonic acid groups, and hydrophobic alkyl long chains. The interfacial activity can be controlled by adjusting the lengths of the hydrophilic and hydrophobic segments.

[0007] To achieve the above objectives, a first aspect of the present invention provides a compound having the structure shown in formula (1):

[0008]

[0009] Where M is H, Na, K or NH4; 1≤n1≤12, 1≤n2≤19.

[0010] A second aspect of the present invention provides a method for preparing a compound, wherein the preparation method includes:

[0011] (1) Under amidation reaction conditions, sulfonated ethanolamine compounds are reacted with acrylic acid compounds;

[0012] (2) Under alkylation reaction conditions, glycol compounds are reacted with bromoalkane substances to obtain ether intermediate products, and then under chlorination reaction conditions, the ether intermediate products are contacted with thionyl chloride to obtain intermediate compounds with the structure shown in formula (10).

[0013]

[0014] Where, 1≤n1≤12, 1≤n2≤19;

[0015] (3) Under etherification reaction conditions, the product obtained in step (1) is brought into contact with the product obtained in step (2) to obtain the compound shown in formula (1).

[0016] A third aspect of the present invention provides a compound prepared by the aforementioned preparation method.

[0017] A fourth aspect of the present invention provides an acrylamide copolymer, wherein the acrylamide copolymer contains structural unit A, structural unit C and structural unit D;

[0018] The structural unit A has the structure shown in equation (2), the structural unit C has the structure shown in equation (3), and the structural unit D has the structure shown in equation (4).

[0019]

[0020] Where R1 is H or methyl; M is H, sodium, potassium or NH4; 1≤n1≤12, 1≤n2≤19.

[0021] A fifth aspect of the present invention provides a method for preparing an acrylamide copolymer, wherein the method comprises:

[0022] (1) Under solution polymerization conditions, in the presence of an initiator, an aqueous solution of alkenyl monomers is subjected to polymerization to obtain a copolymer colloid; the alkenyl monomers include alkenyl monomer A' having the structure shown in formula (6), alkenyl monomer C' having the structure shown in formula (7), and alkenyl monomer D' having the structure shown in formula (8);

[0023]

[0024] Wherein, R1 is H or methyl; M is H, sodium, potassium or NH4; 1≤n1≤12, 1≤n2≤19;

[0025] (2) The copolymer colloid is granulated, hydrolyzed or not hydrolyzed, dried, crushed and sieved to obtain the acrylamide copolymer.

[0026] The sixth aspect of the present invention provides an acrylamide copolymer prepared by the preparation method described above.

[0027] The seventh aspect of the present invention provides the application of the aforementioned acrylamide copolymer as one or more of a modifier, thickener, profile improver and viscosity reducer in oil reservoir development.

[0028] Through the above technical solutions, the compounds and their preparation methods, polymers and their preparation methods, and applications provided by the present invention achieve the following beneficial effects:

[0029] The compound provided by this invention simultaneously possesses hydrophilic polyoxyethylene ether, sulfonic acid groups, and hydrophobic alkane long chains. By adjusting the lengths of the hydrophilic and hydrophobic segments, the interfacial activity can be controlled.

[0030] This monomer is copolymerized with acrylamide and monomers containing rigid structures, introducing a cyclic rigid structure, sulfonic acid monomers, and large side groups with steric hindrance into the ordinary acrylamide polymer structure. This enhances the rigidity of the polymer chain. Simultaneously, its steric hindrance effectively resists the compression of the polymer chain under high temperature and high salinity, improving its temperature resistance, salt resistance, and shear resistance. It exhibits good solubility at 20-95℃ and salinity of 500-50000 mg / L, improving the mobility ratio and effectively expanding the swept volume. Furthermore, by controlling the lengths of the hydrophilic polyoxyethylene ether long chain and the hydrophobic alkane long chain, crude oil can be emulsified and dispersed, reducing interfacial tension. Ordinary heavy oil (50-1000 mPa·s) can be emulsified and dispersed into small droplets, improving oil displacement efficiency. 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. Detailed Implementation

[0031] 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.

[0032] As previously stated, a first aspect of the present invention provides a compound having the structure shown in formula (1):

[0033]

[0034] Where M is H, sodium, potassium or NH4; 1≤n1≤12, 1≤n2≤19.

[0035] According to the present invention, in a preferred embodiment, 1≤n1≤12, 1≤n2≤19, and are integers.

[0036] The inventors of this invention have discovered that when a compound simultaneously contains a hydrophilic polyoxyethylene ether long chain, a sulfonic acid group, and a hydrophobic alkane long chain group, the compound can exhibit good surface / interface activity by adjusting the lengths of the hydrophilic and hydrophobic segments, thus enabling the compound and the polymer prepared therefrom to have good surface / interface activity.

[0037] Furthermore, the inventors of this invention have discovered that when this compound is copolymerized with a monomer containing a rigid cyclic structure and sulfonic acid groups, and with acrylamide, the polymer's salt resistance and shear strength are increased. Its steric hindrance can inhibit hydrolysis at high temperatures, improving the polymer's temperature and salt resistance. Simultaneously, it imparts excellent surface / interfacial activity to the polymer, enabling it to interact with crude oil or ordinary heavy oil, dispersing and emulsifying crude oil, reducing surface / interfacial tension, and improving oil displacement efficiency.

[0038] A second aspect of the present invention provides a method for preparing a compound, wherein the preparation method includes:

[0039] (1) Under amidation reaction conditions, sulfonated ethanolamine compounds are reacted with acrylic acid compounds;

[0040] (2) Under alkylation reaction conditions, glycol compounds are reacted with bromoalkane substances to obtain ether intermediate products, and then under chlorination reaction conditions, the ether intermediate products are contacted with thionyl chloride to obtain intermediate compounds with the structure shown in formula (10).

[0041]

[0042] Where, 1≤n1≤12, 1≤n2≤19;

[0043] (3) Under etherification reaction conditions, the product obtained in step (1) is brought into contact with the product obtained in step (2) to obtain the compound shown in formula (1).

[0044] According to the present invention, the amount of the acrylic acid compound is 0.5-1.5 mol, preferably 0.8-1.2 mol, relative to 1 mol of the ethanolamine compound.

[0045] According to the present invention, relative to 1 mol of glycol, the amount of the bromoalkane is 0.8-1.5 mol, preferably 0.9-1.3 mol, and the amount of thionyl chloride is 0.6-1.5 mol, preferably 0.8-1.3 mol.

[0046] According to the present invention, the acrylic compound is selected from at least one of acrylic acid, acryloyl chloride and acrylic anhydride.

[0047] According to the present invention, the glycol compound is selected from at least one of 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.

[0048] According to the present invention, the bromoalkane is selected from at least one of 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, 1-bromohexadecane, 1-bromoheptadecane, 1-bromooctadecane, and bromoeicosane.

[0049] According to the present invention, in step (1), the amidation reaction conditions include: pH value of 8.5-11.5, preferably 9-10; reaction temperature of 5-75℃, preferably 10-65℃; and reaction time of 6-15 hours, preferably 8-10 hours.

[0050] According to the present invention, in step (2), the alkylation reaction conditions include: a reaction temperature of 10-40°C, preferably 15-25°C, and a reaction time of 1-5 hours, preferably 2-4 hours.

[0051] According to the present invention, in step (2), the chlorination reaction conditions include: a reaction temperature of 60-85°C, preferably 70-80°C; and a reaction time of 6-12 hours, preferably 8-12 hours, and preferably 10-11 hours.

[0052] According to the present invention, in step (3), the etherification reaction conditions include: pH value of 8.5-11.5, preferably 9-10; reaction temperature of 60-90℃, preferably 75-85℃; and reaction time of 2-10 hours, preferably 3-9 hours.

[0053] A third aspect of the present invention provides a compound prepared by the preparation method described above.

[0054] A fourth aspect of the present invention provides an acrylamide copolymer, wherein the acrylamide copolymer contains structural unit A, structural unit C and structural unit D;

[0055] The structural unit A has the structure shown in equation (2), the structural unit C has the structure shown in equation (3), and the structural unit D has the structure shown in equation (4).

[0056]

[0057] Where R1 is H or methyl; M is H, sodium, potassium or NH4; 1≤n1≤12, 1≤n2≤19.

[0058] According to the present invention, in a preferred embodiment, the acrylamide copolymer further comprises structural unit B, which has the structure shown in formula (5);

[0059]

[0060] R2 is H or methyl; M1 is H, sodium, or potassium.

[0061] According to the present invention, R1 and R2 may be the same or different, each being H or methyl; M1 is H, sodium or potassium; M is H, sodium, potassium or NH4; 1≤n1≤12, 1≤n2≤19.

[0062] According to the present invention, in a preferred embodiment, R1 is H, R2 is H, M1 is Na, M is H, n1 = 1, and n2 = 15;

[0063] And / or, R1 is H, R2 is methyl, M1 is H, M is Na, n1 = 5, n2 = 9;

[0064] And / or, R1 is H, R2 is methyl, M1 is H, M is NH4, n1 = 12, n2 = 2.

[0065] According to the present invention, based on the total weight of the acrylamide copolymer, the total content of structural unit A and structural unit B is 85-98% by weight, preferably 87-97% by weight; wherein the content of structural unit B accounts for 10-35% by weight of the total content of structural unit A and structural unit B, preferably 12-30% by weight.

[0066] According to the present invention, based on the total weight of the acrylamide copolymer, the total content of structural unit C and structural unit D is 2-15% by weight, preferably 3-13% by weight; wherein, structural unit C accounts for 10-90% by weight of the total content of structural unit C and structural unit D, preferably 20-50% by weight.

[0067] According to the present invention, the viscosity-average molecular weight of the acrylamide copolymer is 3 million to 15 million, preferably 4.5 million to 13 million.

[0068] A fifth aspect of the present invention provides a method for preparing an acrylamide copolymer, wherein the method comprises:

[0069] (1) Under solution polymerization conditions, in the presence of an initiator, an aqueous solution of alkenyl monomers is subjected to polymerization to obtain a copolymer colloid; the alkenyl monomers include alkenyl monomer A' having the structure shown in formula (6), alkenyl monomer C' having the structure shown in formula (7), and alkenyl monomer D' having the structure shown in formula (8);

[0070]

[0071] Wherein, R1 is H or methyl; M is H, sodium, potassium or NH4; 1≤n1≤12; 1≤n2≤19;

[0072] (2) The copolymer colloid is granulated, hydrolyzed, dried, crushed and sieved to obtain the acrylamide copolymer.

[0073] According to the present invention, in a preferred embodiment, the alkenyl monomer further includes an alkenyl monomer B' with the structure shown in formula (9);

[0074]

[0075] In this case, R2 is H or methyl; M1 is H, sodium or potassium.

[0076] According to the present invention, R1 and R2 may be the same or different, each being H or methyl; M1 is H, sodium or potassium; M is H, sodium, potassium or NH4; 1≤n1≤12, 1≤n2≤19.

[0077] According to the present invention, in a preferred embodiment, R1 is H, R2 is H, M1 is Na, M is H, n1 = 1, and n2 = 15;

[0078] And / or, R1 is H, R2 is methyl, M1 is H, M is Na, n1 = 5, n2 = 9;

[0079] And / or, R1 is H, R2 is methyl, M1 is H, M is NH4, n1 = 12, n2 = 2.

[0080] According to the present invention, based on the total weight of the alkenyl monomers, the total amount of alkenyl monomer A' and alkenyl monomer B' is 85-98% by weight; preferably 87-97% by weight; wherein the amount of alkenyl monomer B' accounts for 10-35% by weight of the total amount of alkenyl monomer A' and alkenyl monomer B', preferably 12-30% by weight.

[0081] According to the present invention, based on the total weight of the alkenyl monomers, the total amount of alkenyl monomer C' and alkenyl monomer D' is 2-15% by weight, preferably 3-13% by weight; wherein, the amount of alkenyl monomer C' accounts for 10-90% by weight of the total amount of alkenyl monomer C' and alkenyl monomer D', preferably 20-50% by weight; and the amount of alkenyl monomer D' accounts for 10-90% by weight of the total amount of alkenyl monomer C' and alkenyl monomer D', preferably 50-80% by weight.

[0082] According to the present invention, the conditions for the solution polymerization reaction include: a temperature of 0°C to 30°C, a time of 4-10 hours, and a pH value of 5-12; preferably, the conditions for the solution polymerization reaction further include: being carried out under an inert atmosphere; 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 an alkaline substance such as sodium hydroxide.

[0083] According to the present invention, the solution polymerization reaction further includes 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. The complexing agent is used to reduce interference from impurities during the polymerization process. The complexing agent is at least one selected from disodium ethylenediaminetetraacetate (EDTA-2Na), sodium aminotriacetate, and diethylenetriaminepentacarboxylate, and the amount of the complexing agent added is 0.01-0.1% by weight of the total weight of the alkenyl monomer mixture, preferably 0.02-0.05% by weight.

[0084] According to the present invention, the polymerization initiation method is at least one of photoinitiation, thermal initiation, radiation initiation, and initiation by adding an initiator; the initiator can be at least one of the initiators commonly used in the art in the prior art, such as: azo initiators, redox initiators, and photoinitiators; the amount of initiator used is the conventional amount, and technicians can select the initiator and the amount of initiator according to the actual situation.

[0085] The amount of the azo initiator is 0.0001-0.1% of the total mass of the monomer mixture, and the amount of the redox initiator is 0.0002-0.3% of the total mass of the monomer mixture; the azo initiator is a water-soluble azo initiator; the redox initiator includes an oxidant and a reducing agent, and the reducing agent is at least one of an inorganic reducing agent and an organic reducing agent; and the mass ratio of the oxidant to the reducing agent is (0.1-1.5):1.

[0086] 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); the oxidant is at least one selected from benzoyl peroxide, hydrogen peroxide, tert-butyl hydroperoxide, 2,5-dimethyl-2,5-bis(hydroperoxide)hexane, ammonium persulfate, sodium persulfate, and potassium persulfate; the inorganic reducing agent is at least one selected from ferrous sulfate, ferrous ammonium sulfate, cuprous chloride, and ferrous sulfate. At least one of potassium sulfate, sodium sulfite, ammonium bisulfite, potassium bisulfite, sodium thiosulfate, potassium thiosulfate, sodium thiosulfate, sodium dithiosulfate, and sodium bisulfite; 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; the photoinitiator is at least one of 2-hydroxy-2,2-dimethylacetophenone and 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylphenylacetone.

[0087] In this invention, the initiator of the redox system is preferably a persulfate oxidant and a sulfite reductant. The persulfate oxidant may be, for example, potassium persulfate, ammonium persulfate, etc. The sulfite may be, for example, potassium bisulfite, sodium bisulfite, etc. Preferably, relative to 100 parts by weight of the monomer mixture, the persulfate oxidant is 0.01-0.1 parts by weight; the sulfite reductant is 0.005-0.05 parts by weight.

[0088] In this invention, the hydrolysis reaction can be carried out under alkaline conditions. These alkaline conditions can be achieved by adding substances such as sodium hydroxide granules. There is no particular limitation on the amount of alkaline substance added, and those skilled in the art can adjust it according to the needs of the reaction. Preferably, the conditions for the hydrolysis reaction include: a temperature of 70-90°C and a time of 2-24 hours.

[0089] Preferably, after granulation, the reaction product is hydrolyzed, dried, pulverized, and sieved to obtain an acrylamide copolymer.

[0090] A preferred embodiment provided by the present invention:

[0091] Methods for preparing acrylamide copolymers include:

[0092] 1) Add monomer C' and monomer D' to deionized water, stir until fully dissolved, and obtain the first functional monomer solution;

[0093] 2) Add acrylamide monomer to a portion of deionized water and stir until homogeneous to obtain an acrylamide monomer solution;

[0094] 3) Add the first functional monomer solution to the acrylamide monomer solution. Preferably, add monomer B'. After stirring thoroughly, adjust the pH value to obtain the second monomer mixture and adjust the reaction temperature.

[0095] 4) After pouring the second monomer mixed solution into the reactor, inert gas is bubbled in, followed by the addition of complex, azo, and redox initiator in sequence. Nitrogen is bubbled in again to mix the mixture evenly. After initiating polymerization, the reactor is sealed to carry out the reaction and obtain polymer colloid.

[0096] 5) The colloid is removed and then granulated, hydrolyzed or not hydrolyzed, dried, pulverized and sieved to obtain an acrylamide copolymer.

[0097] The sixth aspect of the present invention provides an acrylamide copolymer prepared by the preparation method described above.

[0098] The seventh aspect of the present invention provides the application of the aforementioned acrylamide copolymer as one or more of a modifier, thickener, profile improver and viscosity reducer in oil reservoir development.

[0099] This invention introduces rigid cyclic sulfonic acid monomers, tunable polyoxyethylene ether chains with surface-active functions, and large side groups of alkyl chains into the macromolecular chain of polyacrylamide. The resulting acrylamide copolymer exhibits aqueous phase thickening under conditions of 20-95℃ and a salinity of 500-50000 mg / L, while also emulsifying and dispersing crude oil. It can disperse ordinary heavy oil (50-1000 mPa·s) into small droplets, reducing interfacial tension. It is suitable for use as a modifier, thickener, profile improver, or viscosity reducer in conventional reservoirs, high-temperature and high-salinity reservoirs, and ordinary heavy oil reservoirs.

[0100] The present invention will be described in detail below through embodiments.

[0101] In the following examples and comparative examples:

[0102] Acrylamide crystals were purchased from Shandong Nuoer Biotechnology Co., Ltd.

[0103] The monomer C' was prepared according to Example 1 of the acrylamide monomer and its preparation method disclosed in CN105461599B.

[0104] Specifically:

[0105] A condenser, thermometer, constant pressure funnel, drying tube, and mechanical stirrer were installed on a four-necked flask. 16g of acrylonitrile was then placed in the flask, along with 7.23g of camphene and 1.14g of acetic anhydride, and stirred until homogeneous. The mixture was cooled to approximately 0°C in an ice-salt bath. 7g of 104.5% fuming sulfuric acid was placed in the constant pressure funnel and slowly added dropwise, controlling the reaction temperature to be below 10°C. After the addition was complete, the temperature was maintained below 10°C for 30 minutes, then increased to 40°C and reacted for 12 hours, producing a large amount of precipitate. The mixture was then cooled to below 10°C, filtered, washed, and dried to obtain a white solid, namely, the compound with the structure shown below.

[0106]

[0107] The testing method is as follows:

[0108] 1) The residual acrylamide content and shear viscosity retention rate were determined according to the enterprise standard Q / SH1020 1572-2017 "Polyacrylamide for Oil Displacement" of China Petrochemical Corporation Shengli Oilfield Administration.

[0109] 2) Apparent viscosity was measured using a Brookfield viscometer in simulated water with a temperature of 20℃-95℃ and a mineralization of 5000-30000 mg / L.

[0110] 3) The oil dispersibility is determined according to Q / SH1020 1957-2008, and the specific methods include:

[0111] ① Add the polymer to a saline solution with a mineralization of 10000 mg / L to prepare a test solution with a concentration of 1500 mg / L.

[0112] 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.

[0113] ③ Inject 10 mL of the specific crude oil into the above-mentioned stoppered graduated test tube.

[0114] 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.

[0115] 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.

[0116] 4) The interfacial tension of the sample is measured by the "rotation drop method" in the standard "SY / T 5370-2018 Method for Determination of Surface and Interfacial Tension".

[0117] Preparation Example 1

[0118] This preparation example illustrates the compounds and their preparation methods provided by the present invention.

[0119] (1) Sodium 1-hydroxy-2-aminoethanesulfonate (16.2989 g, 100 mmol) was added to a dry three-necked flask, followed by 250 mL of anhydrous THF for dissolution. Then, triethylamine (11.1301 g, 110 mmol) was added. After stirring and dissolving at room temperature (25 °C), the entire system was cooled to 0 °C in a saline bath. Acryloyl chloride (9.0521 g, 110 mmol) was slowly added dropwise. After the addition was complete, stirring was continued for 30 min. After the reaction was completed in 8 hours, the temperature was naturally raised to room temperature (25 °C). Water (100 mL) was added dropwise to quench the reaction system. The reaction product was then extracted with diethyl ether (75 mL × 3) and the organic phase was dried with Na2SO4. After rotary drying, the product was recrystallized (the recrystallization solvent was a mixture of n-hexane and dichloromethane in a volume ratio of 4:1) to obtain a white solid IM1, namely, sodium 2-acrylamido-1-hydroxyethanesulfonate (12.5966 g, 58 mmol).

[0120] The reaction process is as follows:

[0121]

[0122] (2) At room temperature (25°C), ethylene glycol (9.699 g, 156 mmol) was added, followed by 100 mL of anhydrous tetrahydrofuran for dissolution. After complete dissolution, sodium hydride (4.488 g, 187 mmol) was added in three portions, and the reaction was allowed to proceed for 30 minutes. Then, hexadecane bromodiphenyl ether (49.160 g, 161 mmol) was slowly added dropwise. 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 (28.65 g, 100 mmol). Pyridine (11.865 g, 150 mmol) was added, followed by slow dropwise addition of SOCl2 (17.84 g, 150 mmol). After the addition was complete, the mixture was reacted at 70°C until no more HCl and SO2 were released. 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 weakly alkaline, washed with water 5-6 times, and dried by rotary evaporation to obtain intermediate IM2 (18.296, 60 mmol).

[0123] The reaction process is as follows:

[0124]

[0125] (3) Sodium 2-acrylamido-1-hydroxyethanesulfonate (12.5966 g, 58 mmol) was dissolved in tetrahydrofuran (200 mL), potassium carbonate (8.8050 g, 64 mmol) was added, the mixture was stirred until homogeneous, and then heated to 75 °C under reflux. IM2 (18.296 g, 60 mmol) was added, and 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 of the mixed phase was then adjusted to 9 with dilute sodium hydroxide solution. The reaction product was extracted with diethyl ether (75 mL × 3), repeatedly washed with saturated sodium chloride solution, and the organic phase was dried with Na2SO4. After rotary evaporation, the product was recrystallized (the recrystallization solvent was a mixture of dichloromethane and petroleum ether in a volume ratio of 4:1) to obtain compound M1 (12.9828 g, 28 mmol).

[0126] The reaction process is as follows:

[0127]

[0128] M1 has the structure shown in equation (1), where n1 = 1, n2 = 15, and M is Na.

[0129] The structural identification of M1 is as follows:

[0130] 1 H NMR (300MHz, CDCl3) δ: 8.44 (s, 1H), 6.46 (dd, 1H), 6.06 (dd, 1H), 5.72 (dd, 1H), 5. 43(t,1H),3.30-3.70(m,8H),1.41-1.55(m,4H),1.24-2.32(m,24H),0.87(t,3H);

[0131] 13 C NMR (75MHz, CDCl3) δ: 166.9, 131.2, 126.9, 106.1, 70.5, 66.2, 41.1, 31.8, 29.5, 22.6, 14.0.

[0132] Preparation Example 2:

[0133] This preparation example illustrates the compounds and their preparation methods provided by the present invention.

[0134] (1) The intermediate was prepared in the same manner as in Preparation Example 1, that is, the steps for preparing sodium 2-enamido-1-hydroxyethanesulfonate were exactly the same as in Preparation Example 1.

[0135] (2) At room temperature (25°C), add pentaethylene glycol (47.656 g, 200 mmol), add 100 mL of anhydrous tetrahydrofuran to dissolve it, and after complete dissolution, add sodium hydride (5.28 g, 220 mmol) in 4 portions. React for 30 minutes, then slowly add bromodecane (44.457 g, 201 mmol). After the addition is complete, continue the reaction for 2 hours. After the reaction is complete, quench the reaction system with water, then filter to remove the solid, remove unreacted bromodecane by vacuum distillation, and cool to room temperature to obtain an intermediate (36.701 g, 116.67 mmol). Add a certain amount of pyridine (16.611 g, 210 mmol), and slowly add excess SOCl2 (24.983 g, 210 mmol). After the addition is complete, react at 70°C until no more HCl and SO2 are released. The reaction was stopped, cooled to room temperature, and allowed to stand to separate the layers. The upper organic layer was collected, the pH was adjusted to weakly alkaline, and the mixture was washed with water 5-6 times. After rotary evaporation and drying, intermediate IM3 (27.789 g, 70 mmol) was obtained.

[0136] The reaction process is as follows:

[0137]

[0138] (3) Sodium 2-acrylamido-1-hydroxyethanesulfonate (12.5966 g, 58 mmol) was dissolved in tetrahydrofuran (200 mL), potassium carbonate (8.8050 g, 64 mmol) was added, the mixture was stirred evenly, and then heated to 75 °C under reflux. IM3 (27.789 g, 70 mmol) was added, and 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 of the mixed phase was then adjusted to 3 with dilute hydrochloric acid solution. The reaction product was extracted with diethyl ether (75 mL × 3), repeatedly washed with saturated sodium chloride solution, and the organic phase was dried with Na2SO4. After rotary evaporation, the product was recrystallized (the recrystallization solvent was a mixture of dichloromethane and petroleum ether in a volume ratio of 4:1) to obtain compound M2 (16.672 g, 30 mmol).

[0139] The reaction process is as follows:

[0140]

[0141] M2 has the structure shown in equation (1), where n1 = 5, n2 = 9, and M is H.

[0142] The structural identification of M2 is as follows:

[0143] 1H NMR (300MHz, CDCl3) δ: 8.41 (s, 1H), 6.48 (dd, 1H), 6.09 (dd, 1H), 5.74 (dd, 1H), 5.4 2(t,1H),3.35-3.70(m,24H),1.40-1.55(m,5H),1.20-1.35(m,12H),0.88(t,3H);

[0144] 13 C NMR (75MHz, CDCl3) δ: 166.8, 131.0, 126.9, 106.1, 70.5, 66.1, 41.2, 31.7, 29.4, 22.8, 14.0.

[0145] Preparation Example 3:

[0146] This preparation example illustrates the compounds and their preparation methods provided by the present invention.

[0147] (1) Sodium 1-hydroxy-2-aminoethanesulfonate (16.2989 g, 100 mmol) was added to a dry three-necked flask, followed by 250 mL of anhydrous THF for dissolution. Then, triethylamine (11.1301 g, 110 mmol) was added and stirred at room temperature (25 °C) to dissolve. The entire system was then cooled to 0 °C in a saline bath. Acryloyl chloride (9.0521 g, 110 mmol) was slowly added dropwise. After the addition was complete, stirring was continued for 30 min. After the reaction was completed in 8 hours, the temperature was naturally raised to room temperature (25 °C). Ammonia water (100 mL, 15% concentration) was added dropwise to quench the reaction system. The reaction product was then extracted with diethyl ether (75 mL × 3) and the organic phase was dried with Na2SO4. After rotary drying, the product was recrystallized (the recrystallization solvent was a mixture of n-hexane and dichloromethane in a volume ratio of 4:1) to obtain a white solid IM1, which was ammonium 2-acrylamido-1-hydroxyethanesulfonate (7.8517 g, 37 mmol).

[0148] (2) At room temperature (25°C), add dodecaethylene glycol (63.79 g, 116.7 mmol), dissolve in 100 mL of anhydrous tetrahydrofuran, and after complete dissolution, add sodium hydride (3.072 g, 128 mmol) in three portions, reacting for 30 minutes. Then, slowly add bromopropane (14.75 g, 120 mmol) dropwise. After the addition is complete, continue the reaction for 2 hours. After the reaction is complete, quench the reaction system with water, then filter to remove the solid, remove unreacted bromopropane by vacuum distillation, and cool to room temperature to obtain an intermediate (41.2 g, 70 mmol). Add a certain amount of pyridine (8.305 g, 105 mmol), and slowly add excess SOCl2 (12.49 g, 105 mmol) dropwise. After the addition is complete, react at 70°C until no more HCl and SO2 are released. Stop the reaction, cool to room temperature, allow to stand and separate into layers, take the upper organic layer, adjust the pH to weakly alkaline, and wash with water 5-6 times. After rotary evaporation and drying, intermediate IM4 (24.3 g, 40 mmol) was obtained;

[0149]

[0150] (3) Sodium 2-acrylamido-1-hydroxyethanesulfonate (7.8517 g, 37 mmol) was dissolved in tetrahydrofuran (200 mL), potassium carbonate (6.910 g, 50 mmol) was added, the mixture was stirred until homogeneous, and then heated to 75 °C under reflux. IM4 (24.3 g, 40 mmol) was added, and 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 of the mixed phase was then adjusted to 9 with dilute sodium hydroxide solution. The reaction product was extracted with diethyl ether (75 mL × 3), repeatedly washed with saturated sodium chloride solution, and the organic phase was dried with Na2SO4. After rotary evaporation, the product was recrystallized (the recrystallization solvent was a mixture of dichloromethane and petroleum ether in a volume ratio of 4:1) to obtain compound M3 (15.659 g, 20 mmol).

[0151] The reaction process is as follows:

[0152]

[0153] M3 has the structure shown in equation (1), where n1 = 12, n2 = 2, and M is NH4.

[0154] The structural identification of M3 is as follows:

[0155] 1H NMR (300MHz, CDCl3) δ: 8.43 (s, 1H), 6.47 (dd, 1H), 6.07 (dd, 1H), 5.71 (dd, 1H), 5.40 (t, 1H), 3.30-3.60 (m, 52H), 1.45-1.50 (m, 3H), 0.97 (t, 3H);

[0156] 13 C NMR (75MHz, CDCl3) δ: 166.6, 130.9, 126.7, 106.4, 70.3, 66.0, 41.4, 27.4, 10.3.

[0157] Example 1

[0158] This embodiment is intended to illustrate the acrylamide copolymer prepared according to the present invention.

[0159] Add 1g of monomer C' to 40g of deionized water. The structural formula is:

[0160] 3g of monomer D' (M1 in Preparation Example 1) was stirred until homogeneous to obtain a functional monomer solution.

[0161] Add 40g of monomer A'acrylamide to 150g of water, stir until dissolved, then add to the functional monomer solution. Add deionized water to bring the total weight to 300g, adjust the pH to 6.0, and control the initial temperature at 0℃. Purge the system with nitrogen for 20 minutes to remove oxygen. Then add 0.03g of EDTA-2Na, 1.0g of 0.25% 2,2′-azobis(2-amidinepropane) dihydrochloride aqueous solution, 5g of 0.2% ammonium persulfate aqueous solution, and 1.5g of 0.6% 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 resulting colloid, add 3.38g of sodium hydroxide, and hydrolyze at 70℃ for 8 hours. Dry at 60℃ until the solid content reaches over 89%, then pulverize and sieve to obtain the polymer dry powder product, i.e., the acrylamide copolymer.

[0162] Based on the calculation of the feed amount, the prepared acrylamide copolymer contains structural unit A, structural unit B, structural unit C and structural unit D; wherein, structural unit B is obtained by reacting part of structural unit A with sodium hydroxide; and based on the total weight of the acrylamide copolymer, the content of structural unit A is 77.3 wt%, the content of structural unit B is 13.6 wt%, the content of structural unit C is 2.3 wt%, and the content of structural unit D is 6.8 wt%.

[0163] The apparent viscosity, residual monomer content, shear viscosity retention, oil dispersion ability for 100 mPa·s, 500 mPa·s, and 1000 mPa·s heavy oil, and interfacial tension of the obtained polymer dry powder products are shown in Table 1.

[0164] Example 2

[0165] This embodiment is intended to illustrate the acrylamide copolymer prepared according to the present invention.

[0166] Add 2.5g of monomer C' to 40g of deionized water. The structural formula is:

[0167] 2.5g of monomer D' (M2 in Preparation Example 2) was stirred until homogeneous to obtain a functional monomer solution.

[0168] Add 45g of monomer A'acrylamide and 15g of monomer B'sodium acrylate to 150g of water, stir until dissolved, and then add to the functional monomer solution. Add deionized water to bring the total weight to 300g, adjust the pH to 6.0, and control the initial temperature at 5℃. Purge the system with nitrogen for 20 minutes to remove oxygen. Then add 0.03g of EDTA-2Na, 1.0g of 0.25% aqueous solution of 2,2′-azobis(2-amidinylpropane) dihydrochloride, 5g of 0.2% aqueous solution of ammonium persulfate, and 1.5g of 0.6% aqueous solution of sodium bisulfite 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 resulting colloid, dry it at 60℃ until the solid content reaches over 89%, pulverize and sieve to obtain the polymer dry powder product, i.e., the acrylamide copolymer.

[0169] Based on the amount of feed, the prepared acrylamide copolymer contains structural unit A, structural unit B, structural unit C and structural unit D; and based on the total weight of the acrylamide copolymer, the content of structural unit A is 69.3% by weight, the content of structural unit B is 23.1% by weight, the content of structural unit C is 3.8% by weight, and the content of structural unit D is 3.8% by weight.

[0170] The apparent viscosity, residual monomer content, shear viscosity retention, oil dispersion ability for 100 mPa·s, 500 mPa·s, and 1000 mPa·s heavy oil, and interfacial tension of the obtained polymer dry powder products are shown in Table 1.

[0171] Example 3

[0172] This embodiment is intended to illustrate the acrylamide copolymer prepared according to the present invention.

[0173] Add 1g of monomer C' to 50g of deionized water. The structural formula is:

[0174] 2.5g of monomer D' (M3 in Preparation Example 3) was stirred until homogeneous to obtain a functional monomer solution.

[0175] Add 45g of monomer A'acrylamide to 150g of water, stir until dissolved, then add to the functional monomer solution. Add deionized water to bring the total weight to 300g, adjust the pH to 6.0, and control the initial temperature at 15℃. Purge the system with nitrogen for 20 minutes to remove oxygen. Then add 0.03g of EDTA-2Na, 1.0g of 0.25% 2,2′-azobis(2-amidinepropane) dihydrochloride aqueous solution, 5g of 0.2% ammonium persulfate aqueous solution, and 1.5g of 0.6% 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 resulting colloid, add 6.34g of sodium hydroxide, and hydrolyze at 70℃ for 8 hours. Dry at 60℃ until the solid content reaches over 89%, then pulverize and sieve to obtain the polymer dry powder product, i.e., the acrylamide copolymer.

[0176] Based on the amount of feed, the prepared acrylamide copolymer contains structural unit A, structural unit B, structural unit C and structural unit D; and based on the total weight of the acrylamide copolymer, the content of structural unit A is 69.6% by weight, the content of structural unit B is 23.1% by weight, the content of structural unit C is 2.1% by weight, and the content of structural unit D is 5.2% by weight.

[0177] The apparent viscosity, residual monomer content, shear viscosity retention, oil dispersion ability for 100 mPa·s, 500 mPa·s, and 1000 mPa·s heavy oil, and interfacial tension of the obtained polymer dry powder products are shown in Table 1.

[0178] Example 4

[0179] This embodiment is intended to illustrate the acrylamide copolymer prepared according to the present invention.

[0180] Add 1.5g of monomer C' to 40g of deionized water. The structural formula is:

[0181] 5.5g of monomer D' (M2 in Preparation Example 2) was stirred until homogeneous to obtain a functional monomer solution.

[0182] Add 70g of monomer A' acrylamide to 150g of water, add 9.85g of sodium hydroxide, stir until dissolved, then add to the functional monomer solution. Add deionized water to bring the total weight to 300g, adjust the pH to 12.0, and control the initial temperature at 5℃. Purge the system with nitrogen for 20 minutes to remove oxygen. Then add 0.03g of EDTA-2Na, 1.0g of 0.25% 2,2′-azobis(2-amidinylpropane) dihydrochloride aqueous solution, 5g of 0.2% ammonium persulfate aqueous solution, and 1.5g of 0.6% 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 resulting colloid, keep it at 70℃ for 10 hours, dry it at 60℃ until the solid content reaches over 89%, pulverize and sieve to obtain the polymer dry powder product, i.e., the acrylamide copolymer.

[0183] Based on the calculation of the feed amount, the prepared acrylamide copolymer contains structural unit A, structural unit B, structural unit C and structural unit D; wherein, structural unit B is obtained by reacting a portion of structural unit A with sodium hydroxide; and based on the total weight of the acrylamide copolymer, the content of structural unit A is 68.3% by weight, the content of structural unit B is 22.7% by weight, the content of structural unit C is 1.9% by weight, and the content of structural unit D is 7.1% by weight.

[0184] The apparent viscosity, residual monomer content, shear viscosity retention, oil dispersion ability for 100 mPa·s, 500 mPa·s, and 1000 mPa·s heavy oil, and interfacial tension of the obtained polymer dry powder products are shown in Table 1.

[0185] Example 5

[0186] This embodiment is used to illustrate the oil displacement polymer prepared according to the present invention.

[0187] Add 1g of monomer C' to 40g of deionized water. The structural formula is:

[0188] 3g of monomer D' (M2 in Preparation Example 2) was stirred until homogeneous to obtain a functional monomer solution.

[0189] Add 70g of monomer A'acrylamide and 12g of monomer B'methacrylic acid to 150g of water, stir until dissolved, and then add to the functional monomer solution. Add deionized water to bring the total weight to 300g, adjust the pH to 6.0, and control the initial temperature at 10℃. Purge the system with nitrogen for 20 minutes to remove oxygen. Then add 0.03g of EDTA-2Na, 1.0g of 0.25% 2,2′-azobis(2-amidinylpropane) dihydrochloride aqueous solution, 5g of 0.2% ammonium persulfate aqueous solution, and 1.5g of 0.6% 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 resulting colloid, dry it at 60℃ until the solid content reaches over 89%, pulverize and sieve to obtain the polymer dry powder product, i.e., the oil-displacing polymer.

[0190] Based on the amount of feed, the acrylamide copolymer contains structural unit A, structural unit B, structural unit C, and structural unit D; and based on the total weight of the oil-displacing polymer, the content of structural unit A is 81.4% by weight, the content of structural unit B is 13.9% by weight, the content of structural unit C is 1.2% by weight, and the content of structural unit D is 3.5% by weight.

[0191] The apparent viscosity, residual monomer content, shear viscosity retention, oil dispersion ability for 100 mPa·s, 500 mPa·s, and 1000 mPa·s heavy oil, and interfacial tension of the obtained polymer dry powder products are shown in Table 1.

[0192] Comparative Example 1

[0193] Acrylamide copolymers were prepared using the same method as in Example 1, except that monomer D' (M1 in Preparation Example 1) was not added.

[0194] Based on the amount of feed, the prepared acrylamide copolymer contains structural unit A, structural unit B, and structural unit C; wherein structural unit B is obtained by reacting a portion of structural unit A with sodium hydroxide; and based on the total weight of the acrylamide copolymer, the content of structural unit A is 83.0 wt%, the content of structural unit B is 14.6 wt%, and the content of structural unit C is 2.4 wt%.

[0195] The apparent viscosity, residual monomer content, shear viscosity retention, oil dispersion ability for 100 mPa·s, 500 mPa·s, and 1000 mPa·s heavy oil, and interfacial tension of the obtained polymer dry powder products are shown in Table 1.

[0196] Comparative Example 2

[0197] Acrylamide copolymers were prepared using the same method as in Example 2, except that monomer D' (M2 in Preparation Example 2) was not added.

[0198] Based on the amount of feed, the prepared acrylamide copolymer contains structural unit A, structural unit B, and structural unit C; and based on the total weight of the acrylamide copolymer, the content of structural unit A is 72.0% by weight, the content of structural unit B is 24.0% by weight, and the content of structural unit C is 4.0% by weight.

[0199] The apparent viscosity, residual monomer content, shear viscosity retention, oil dispersion ability for 100 mPa·s, 500 mPa·s, and 1000 mPa·s heavy oil, and interfacial tension of the obtained polymer dry powder products are shown in Table 1.

[0200] Comparative Example 3

[0201] Acrylamide copolymers were prepared using the same method as in Example 3, except that monomer D' (M3 in Preparation Example 3) was not added.

[0202] Based on the amount of feed, the prepared acrylamide copolymer contains structural unit A, structural unit B, and structural unit C; wherein structural unit B is obtained by reacting a portion of structural unit A with sodium hydroxide; and based on the total weight of the acrylamide copolymer, the content of structural unit A is 73.3% by weight, the content of structural unit B is 24.5% by weight, and the content of structural unit C is 2.2% by weight.

[0203] The apparent viscosity, residual monomer content, shear viscosity retention, oil dispersion ability for 100 mPa·s, 500 mPa·s, and 1000 mPa·s heavy oil, and interfacial tension of the obtained polymer dry powder products are shown in Table 1.

[0204] Table 1

[0205]

[0206]

[0207] The data in the table above shows that:

[0208] (1) The apparent viscosity and shear viscosity retention of the polymers obtained in Examples 1-5 are much higher than those in Comparative Example 1, indicating that the introduction of a cyclic rigid structure into the system enhances the rigidity of the polymer chain. At the same time, the introduction of sulfonic acid groups with steric hindrance can effectively resist the compression of the polymer chain under high temperature and high mineralization. While having the effect of water phase thickening, the shear resistance is also significantly improved.

[0209] (2) Meanwhile, the crude oil dispersion ability of Examples 1-5 is much higher than that of Comparative Example 1, indicating that the introduction of hydrophilic polyoxyethylene ether long chain and lipophilic alkyl long chain, and by controlling the length of hydrophilic and lipophilic segments, can make the polymer have excellent surface / interfacial activity and disperse emulsified crude oil.

[0210] 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. An acrylamide copolymer, characterized in that, The acrylamide copolymer contains structural unit A, structural unit C and structural unit D; The structural unit A has the structure shown in formula (2), the structural unit C has the structure shown in formula (3), and the structural unit D is provided by the compound shown in M1, M2 or M3; Equation (2); Equation (3); ； ； ； Where R1 is H or methyl; M is sodium.

2. The copolymer according to claim 1, wherein, The acrylamide copolymer also contains structural unit B, which has the structure shown in formula (5); Equation (5); R2 is H or methyl; M1 is H, sodium, or potassium.

3. The copolymer according to claim 2, wherein, R1 is H, R2 is methyl, M1 is H, and M is Na.

4. The copolymer according to any one of claims 1-3, wherein, Based on the total weight of the acrylamide copolymer, the total content of structural unit A and structural unit B is 85-98% by weight; wherein, the content of structural unit B accounts for 10-35% by weight of the total content of structural unit A and structural unit B. Based on the total weight of the acrylamide copolymer, the total content of structural unit C and structural unit D is 2-15% by weight; wherein, structural unit C accounts for 10-90% by weight of the total content of structural unit C and structural unit D.

5. The copolymer according to claim 4, wherein, Based on the total weight of the acrylamide copolymer, the total content of structural unit A and structural unit B is 87-97% by weight; wherein, the content of structural unit B accounts for 12-30% by weight of the total content of structural unit A and structural unit B. Based on the total weight of the acrylamide copolymer, the total content of structural unit C and structural unit D is 3-13% by weight; wherein, structural unit C accounts for 20-50% by weight of the total content of structural unit C and structural unit D.

6. The copolymer according to claim 1, wherein, The structural unit D is provided by the compound shown in M1; ； Where M represents sodium.

7. The copolymer according to claim 1, wherein, The method for preparing the compound includes: (1) Under amidation reaction conditions, sulfonated ethanolamine compounds are reacted with acrylic acid compounds; (2) Under alkylation reaction conditions, glycol compounds are reacted with bromoalkane substances to obtain ether intermediate products, and then under chlorination reaction conditions, the ether intermediate products are contacted with thionyl chloride to obtain intermediate compounds with structures as shown in formula (10), formula (11) or formula (12). Equation (10); , Equation (11); Equation (12); (3) Under the etherification reaction conditions, the product obtained in step (1) is brought into contact with the product obtained in step (2) to obtain the compound shown in M1, M2 or M3.

8. The copolymer according to claim 7, wherein, The amount of the acrylic acid compound used is 0.5-1.5 mol relative to 1 mol of the sulfonated ethanolamine compound; And / or, relative to 1 mol of the glycol, the amount of the bromoalkane is 0.8-1.5 mol, and the amount of the thionyl chloride is 0.6-1.5 mol; And / or, the glycol compound is selected from ethylene glycol, pentaethylene glycol or dodecaethylene glycol; And / or, the bromoalkane is selected from bromopropane, 1-bromodecane or 1-bromohexadecane.

9. The copolymer according to claim 8, wherein, The amount of the acrylic acid compound used is 0.8-1.2 mol relative to 1 mol of the sulfonated ethanolamine compound; And / or, relative to 1 mol of the glycol, the amount of the bromoalkane is 0.9-1.3 mol, and the amount of the thionyl chloride is 0.8-1.3 mol.

10. The copolymer according to claim 7, wherein, The acrylic compound is selected from at least one of acrylic acid, acryloyl chloride, and acrylic anhydride.

11. The copolymer according to claim 7, wherein, In step (1), the amidation reaction conditions include: a reaction temperature of 5-75°C and a reaction time of 6-15 hours; And / or, in step (2), the alkylation reaction conditions include: a reaction temperature of 10-40°C and a reaction time of 1-5 hours; And / or, in step (2), the chlorination reaction conditions include: a reaction temperature of 60-85°C and a reaction time of 6-12 hours; And / or, in step (3), the etherification reaction conditions include: pH value of 8.5-11.5, reaction temperature of 60-90℃, and reaction time of 2-10 hours.

12. The copolymer according to claim 11, wherein, In step (1), the amidation reaction conditions include: a reaction temperature of 10-65℃ and a reaction time of 8-10 hours; And / or, in step (2), the alkylation reaction conditions include: a reaction temperature of 15-25°C and a reaction time of 2-4 hours; And / or, in step (2), the chlorination reaction conditions include: a reaction temperature of 70-80°C and a reaction time of 8-11 hours; And / or, in step (3), the etherification reaction conditions include: pH value of 9-10, reaction temperature of 75-85℃, and reaction time of 3-9 hours.

13. A method for preparing the acrylamide copolymer according to any one of claims 1-12, characterized in that, The preparation method includes: (1) Under solution polymerization conditions, in the presence of an initiator, an aqueous solution of alkenyl monomers is subjected to polymerization to obtain a copolymer colloid; the alkenyl monomers include alkenyl monomers A' having the structure shown in formula (6), alkenyl monomers C' having the structure shown in formula (7), and alkenyl monomers D' provided by compounds shown in M1, M2, or M3; Equation (6); Equation (7); ； ； ； Wherein, R1 is H or methyl; M is sodium; (2) The copolymer colloid is granulated, hydrolyzed or not hydrolyzed, dried, crushed and sieved to obtain the acrylamide copolymer.

14. The preparation method according to claim 13, wherein, The alkenyl monomer also includes the alkenyl monomer B' with the structure shown in formula (9); Equation (9); In this case, R2 is H or methyl; M1 is H, sodium or potassium.

15. The preparation method according to claim 14, wherein, R1 is H, R2 is methyl, M1 is H, and M is Na.

16. The preparation method according to claim 14, wherein, Based on the total weight of the alkenyl monomers, the total amount of alkenyl monomer A' and alkenyl monomer B' is 85-98% by weight; wherein, the amount of alkenyl monomer B' accounts for 10-35% by weight of the total amount of alkenyl monomer A' and alkenyl monomer B'. And / or, based on the total weight of the alkenyl monomers, the total amount of alkenyl monomer C' and alkenyl monomer D' is 2-15% by weight; wherein the amount of alkenyl monomer C' accounts for 10-90% by weight of the total amount of alkenyl monomer C' and alkenyl monomer D'.

17. The preparation method according to claim 16, wherein, Based on the total weight of the alkenyl monomers, the total amount of alkenyl monomer A' and alkenyl monomer B' is 87-97% by weight; wherein, the amount of alkenyl monomer B' accounts for 12-30% by weight of the total amount of alkenyl monomer A' and alkenyl monomer B'. And / or, based on the total weight of the alkenyl monomers, the total amount of alkenyl monomer C' and alkenyl monomer D' is 3-10% by weight; wherein the amount of alkenyl monomer C' accounts for 20-50% by weight of the total amount of alkenyl monomer C' and alkenyl monomer D'.

18. The preparation method according to claim 13, wherein, The conditions for the solution polymerization reaction include: a temperature of 0°C to 30°C, a time of 4-10 hours, and a pH of 5-12. And / or, the hydrolysis conditions include: a temperature of 70-90°C and a time of 2-24 hours.

19. The preparation method according to claim 18, wherein, The conditions for the solution polymerization reaction also include: being carried out under an inert atmosphere.

20. The preparation method according to claim 13, wherein, The initiator includes at least one of azo initiators, redox initiators, and photoinitiators; And / or, the conditions for the solution polymerization reaction further include: being carried out in the presence of a complexing agent; wherein the complexing agent includes one or more of disodium ethylenediaminetetraacetate, sodium aminotriacetate, and diethylenetriaminepentacarboxylate; and the amount of the complexing agent is 0.01-0.1 by weight based on the total weight of the alkenyl monomer.

21. The use of an acrylamide copolymer according to any one of claims 1-12 as one or more of a modifier, thickener, profile improver and viscosity reducer in oil reservoir development.

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