Compounds with acrylamide polymers having oil displacement effect, and preparation method and application thereof

Abstract

The application relates to the polymer field and discloses a compound with an oil displacement acrylamide polymer and a preparation method and application thereof, the structure of the compound is shown in the following formula, wherein 1<=n1<=4, 5<=n2<=19, and n1 and n2 are integers. The polymer prepared from the compound has the characteristics of temperature viscosity increase and salt viscosity increase within a certain temperature and salinity range, can effectively resist compression of polymer molecular chains in a high-temperature and high-salinity environment, can keep high viscosity under high temperature and high salinity while improving temperature resistance and salt resistance, and the synthesized copolymer also has certain interfacial activity and the ability of emulsifying and dispersing crude oil.

Description

Technical Field

[0001] This invention relates to the field of polymers, specifically to a compound and an acrylamide polymer with oil displacement properties, as well as its preparation method and application. Background Technology

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

[0003] However, with the full utilization of high-quality resources in Class I and II reservoirs, the complex and demanding reservoir conditions pose new challenges to the development and innovation of chemical flooding technology. These include the high-temperature and high-salinity environment of Class III and above reservoirs; high-permeability and high-water-cut reservoir environments after chemical flooding; and heavy oil reservoir environments with low recovery rates. Existing research indicates that conventional chemical flooding agents have limited viscosity-increasing effects in these environments. Therefore, the reduction in the heavy oil / water mobility ratio and the expansion of the swept volume are small, failing to meet the needs of oilfield development. Conventional temperature- and salt-resistant polymers address the viscosity reduction problem of polymer solutions under high temperature and high salinity by increasing polymer chain rigidity and molecular weight, but the effect is limited. Chain rigidity can resist the effects of high temperature and high salinity to some extent, but it will worsen solubility. Simultaneously, the increase in polymer molecular weight is limited; otherwise, it will lead to easy mechanical degradation and poor shear resistance. Furthermore, introducing a small number of hydrophobic groups to form hydrophobically associated polymers is currently reported as a relatively effective method to increase the viscosity of the aqueous phase; however, the introduction of these hydrophobic groups results in poor solubility.

[0004] Therefore, preparing a polymer with temperature- and salt-induced viscosity-enhancing properties that can effectively resist the compression of polymer molecular chains under high temperature and high salinity environments, while improving temperature and salt resistance and maintaining high viscosity under high temperature and high salinity, is of great significance for improving the recovery rate of chemical flooding. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned problems existing in the prior art and to provide a compound and an acrylamide polymer with oil displacement function, as well as its preparation method and application. The compound contains long-chain alkane nonpolar groups, rigid groups (benzene ring and six-membered ring) and polar groups, and has great rigidity and steric hindrance effect, which can suppress molecular chain compression under high temperature and high mineralization. At the same time, it has a certain interfacial activity and can react with crude oil.

[0006] To achieve the above objectives, the present invention provides a compound, characterized in that the structure of the compound is as follows:

[0007]

[0008] Where 1≤n1≤4, 5≤n2≤19, and n1 and n2 are integers.

[0009] A second aspect of the present invention provides an application of the above-mentioned compound in the preparation of an acrylamide polymer with oil displacement properties.

[0010] A third aspect of the present invention provides a method for preparing the above-mentioned compound, characterized in that the method comprises:

[0011] (1) Under amidation reaction conditions, 6-hydroxy-1,2,3,4-tetrahydroquinoline was contacted with acryloyl chloride to carry out an amidation reaction;

[0012] (2) Under alkylation reaction conditions, glycols and bromoalkanes are mixed and subjected to an alkylation reaction; the glycol compound has the following structure: 1 ≤ n1 ≤ 4, and are integers; the structure of brominated alkanes is: 5 ≤ n² ≤ 19, and n is an integer;

[0013] (3) Under chlorination reaction conditions, the product of step (2) is contacted with thionyl chloride to carry out chlorination reaction;

[0014] (4) Under the etherification reaction conditions, the product of step (1) and the product of step (3) are mixed to carry out the etherification reaction.

[0015] A fourth aspect of the present invention provides a preparation of an acrylamide polymer with oil displacement function, characterized in that the polymer comprises structural unit I, structural unit C and structural unit D, wherein structural unit I is structural unit A and / or structural unit B, and the content of structural unit I is 85-98% by weight, based on the weight of the polymer; the content of structural unit C is 1-7.5% by weight; and the content of structural unit D is 1-7.5% by weight.

[0016] The structural unit A is The structural unit B is

[0017] The structural unit C is The structural unit D is

[0018] Wherein, R1 and R2 are H or methyl, M1 is hydrogen or alkali metal; R3 and R4 are each independently one of hydrogen or C4-C18 alkyl; 1≤n1≤4, 5≤n2≤19, and n1 and n2 are integers.

[0019] The fifth aspect of this invention provides a method for producing an acrylamide polymer with oil displacement effect, characterized in that the method comprises: under solution polymerization conditions, in the presence of an initiator, causing an alkenyl monomer in an alkenyl monomer solution to undergo a polymerization reaction, characterized in that the alkenyl monomer comprises monomer I', monomer C', and monomer D'; monomer I' is monomer A' and / or monomer B', and based on the total weight of the alkenyl monomer in the alkenyl monomer solution, the content of monomer I' is 85-98% by weight; the content of monomer C' is 1-7.5% by weight; and the content of monomer D' is 1-7.5% by weight.

[0020] The monomer A' is The monomer B' The monomer C' is The monomer D' is

[0021] Wherein, R1 and R2 are H or methyl, M1 is hydrogen or alkali metal; R3 and R4 are each independently one of hydrogen or C4-C18 alkyl; 1≤n1≤4, 5≤n2≤19, and n1 and n2 are integers.

[0022] A sixth aspect of the present invention provides an acrylamide polymer with oil displacement function, characterized in that the polymer is prepared by the method described above.

[0023] The seventh aspect of the present invention provides an application of the above-mentioned polymer in oil reservoir development as at least one of a modifier, oil displacement agent, profile improver, and viscosity reducer.

[0024] The above technical solution has achieved at least the following beneficial effects:

[0025] (1) The compounds prepared by this invention contain long-chain alkane nonpolar groups, rigid groups (benzene ring and six-membered ring) and polar groups, which have great rigidity and steric hindrance effect, can suppress molecular chain compression under high temperature and high mineralization, and at the same time have certain interfacial activity and can react with crude oil.

[0026] (2) The polymer prepared using the compound of the present invention exhibits temperature- and salt-induced viscosity-enhancing properties within a certain temperature and salinity range. It can effectively resist the compression of polymer molecular chains under high temperature and high salinity conditions, and while improving temperature and salt resistance, it can maintain high viscosity under high temperature and high salinity conditions. In addition, the synthesized copolymer also has certain interfacial activity and the ability to emulsify and disperse crude oil. It can be used as an oil displacement agent, thickener, profile improver, and viscosity reducer for polymer flooding in conventional reservoirs, high-temperature and high-salinity reservoirs, and ordinary heavy oil reservoirs. Detailed Implementation

[0027] 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.

[0028] In one aspect, the present invention provides a compound, characterized in that the structure of the compound is as follows:

[0029]

[0030] Wherein, 1≤n1≤4, 5≤n2≤19, and n1 and n2 are integers. For example, n1 can be 1, 2, 3 or 4; n2 can be 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 or 19. Preferably, 9≤n2≤17.

[0031] In this invention, the inventors discovered that the compound described in this invention has a rigid structure (benzene ring and six-membered ring) and long-chain alkane groups. Its rigidity and steric hindrance effect can increase the compressibility of the polymer chain under high temperature and high salinity conditions, and improve the temperature and salt resistance of the polymer.

[0032] A second aspect of the present invention provides an application of the above-mentioned compound in the preparation of an acrylamide polymer with oil displacement properties.

[0033] A third aspect of the present invention provides a method for preparing the above-mentioned compound, characterized in that the method comprises:

[0034] (1) Under amidation reaction conditions, 6-hydroxy-1,2,3,4-tetrahydroquinoline was contacted with acryloyl chloride to carry out an amidation reaction;

[0035] (2) Under alkylation reaction conditions, glycols and bromoalkanes are mixed and subjected to an alkylation reaction; the glycol compound has the following structure: 1 ≤ n1 ≤ 4, and are integers; the structure of brominated alkanes is: 5 ≤ n² ≤ 19, and n is an integer;

[0036] (3) Under chlorination reaction conditions, the product of step (2) is contacted with thionyl chloride to carry out chlorination reaction;

[0037] (4) Under the etherification reaction conditions, the product of step (1) and the product of step (3) are mixed to carry out the etherification reaction.

[0038] In this invention, the amount of each raw material used in the preparation of the compound is not particularly limited. Preferably, relative to 1 mol of 6-hydroxy-1,2,3,4-tetrahydroquinoline, the amount of acryloyl chloride is 0.5-1.5 mol, more preferably 0.8-1.2 mol. Further preferably, relative to 1 mol of glycol, the amount of bromoalkane is 0.8-1.5 mol, preferably 0.9-1.3 mol. More preferably, relative to 1 mol of the product of step (2), the amount of thionyl chloride is 0.8-2 mol, preferably 1-1.8 mol. Further preferably, in step (4), the molar ratio of the product of step (1) to the product of step (3) is 1:0.9-1.5.

[0039] Preferably, the glycol is selected from ethylene glycol, diethylene glycol, or triethylene glycol. More preferably, the bromoalkane is selected from 1-bromohexane, 1-bromoheptane, 1-bromooctane, 1-bromononane, 1-bromodecane, 1-bromoundecane, 1-bromododecane, 1-bromotridecane, 1-bromotetradecane, 1-bromopentadecane, bromohexadecane, 1-bromoheptadecane, 1-bromooctadecane, or bromoeicosane.

[0040] In this invention, the amidation reaction conditions in step (1) can be the reaction conditions commonly used in amidation reactions. Preferably, the amidation reaction conditions in step (1) include: a temperature of 0-35°C, preferably 10-25°C; and a time of 6-15h, preferably 8-10h.

[0041] In this invention, the alkylation reaction conditions in step (2) can be the reaction conditions commonly used in alkylation reactions. Preferably, the alkylation reaction conditions in step (2) include: a temperature of 0-35°C, preferably 15-30°C; and a time of 1.5-6h, preferably 2-4h.

[0042] In this invention, the chlorination reaction conditions in step (3) can be the reaction conditions commonly used in chlorination reactions. Preferably, the chlorination reaction conditions in step (3) include: a temperature of 60-90℃, preferably 65-75℃; and a time of 8-12h, preferably 10-11h.

[0043] In this invention, the etherification reaction conditions in step (4) can be the reaction conditions commonly used in etherification reactions. Preferably, the etherification reaction conditions in step (4) include: a temperature of 60-90℃, preferably 75-85℃; and a time of 2-10h, preferably 4-8h.

[0044] Preferably, the method further includes purifying at least one of the reaction products from steps (1), (3), and (4). In this invention, the method for purifying the reaction products is not particularly limited; for example, extraction and recrystallization can be used independently for purification. According to a specific embodiment of the invention, the purification is carried out as follows: the reaction product is quenched with water, then extracted with diethyl ether, and the extracted organic phase is dried with sodium sulfate. The dried product is then evaporated to dryness, and subsequently recrystallized with n-hexane and / or dichloromethane.

[0045] A fourth aspect of the present invention provides an acrylamide polymer with oil displacement effect, characterized in that the polymer comprises structural unit I, structural unit C, and structural unit D, wherein structural unit I is structural unit A and / or structural unit B, and the content of structural unit I is 85-98% by weight, based on the weight of the polymer; the content of structural unit C is 1-7.5% by weight; and the content of structural unit D is 1-7.5% by weight.

[0046] The structural unit A is The structural unit B is

[0047] The structural unit C is The structural unit D is

[0048] Wherein, R1 and R2 are H or methyl, M1 is hydrogen or alkali metal; R3 and R4 are each independently hydrogen or C4-C18 alkyl; 1≤n1≤4, 5≤n2≤19, and n1 and n2 are integers, for example, n1 can be 1, 2, 3 or 4; n2 can be 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 or 19.

[0049] Preferably, 9 ≤ n2 ≤ 17.

[0050] The polymer of this invention introduces different types of polar and nonpolar groups into the conventional acrylamide molecular chain, resulting in hydrogen bonding and nonpolar interactions between the molecular chains. The resulting polymer exhibits temperature- and salt-induced viscosity increases within a certain temperature and salinity range. This is because the long-chain alkane nonpolar groups in the compound can form nonpolar aggregates with the nonpolar groups in the long-chain alkyl disubstituted acrylamide, increasing the intermolecular forces and thus increasing the bulk viscosity, exhibiting temperature- and salt-induced viscosity increases. Simultaneously, the rigid groups and steric hindrance in the compound effectively resist the compression of the polymer molecular chain under high temperature and high salinity conditions, improving temperature and salt resistance while maintaining high viscosity at these conditions. Furthermore, the synthesized copolymer also possesses certain interfacial activity, exhibiting the ability to emulsify and disperse crude oil. The polymer of this invention exhibits good solubility at 20-85°C and a salinity of 500-50000 mg / L. It has good thickening ability in aqueous phase, can effectively improve mobility ratio and expand swept volume, and also has certain interfacial activity. It can emulsify and disperse crude oil and can be used as an oil displacement agent and profile improver for polymer flooding in conventional oil reservoirs, high-temperature and high-salinity oil reservoirs, and ordinary heavy oil reservoirs.

[0051] In this invention, structural unit I may not contain structural unit B. In this case, the content of structural unit B is 0% by weight of the content of structural unit I, and the content of structural unit A is 100% by weight of the content of structural unit I. Preferably, structural unit I contains structural unit B, and the content of structural unit B is 6-35% by weight of the content of structural unit I, preferably 8-30% by weight. Structural unit B can be obtained by hydrolyzing structural unit A (specific hydrolysis method is described later), or it can be obtained by introducing monomer B' during the preparation process. In order to obtain a polymer with the content of structural unit B meeting the above requirements, those skilled in the art can make appropriate selections.

[0052] In this invention, the alkyl group can be straight-chain or branched, preferably straight-chain. More preferably, it is butyl, pentyl, hexyl, heptyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, or octadecyl. Even more preferably, it is hexyl, heptyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, or octadecyl. Even more preferably, it is one of C6-C16 alkyl groups.

[0053] Preferably, the alkali metal is Na or K. More preferably, the polymer has a viscosity-average molecular weight of 6-15 million, and more preferably 8-14 million.

[0054] The fifth aspect of this invention provides a method for preparing an acrylamide polymer with oil displacement properties, characterized in that the method comprises: under solution polymerization conditions, in the presence of an initiator, causing an alkenyl monomer in an alkenyl monomer solution to undergo a polymerization reaction, characterized in that the alkenyl monomer comprises monomer I', monomer C', and monomer D'; monomer I' is monomer A' and / or monomer B', and based on the total weight of the alkenyl monomer in the alkenyl monomer solution, the content of monomer I' is 85-98% by weight; the content of monomer C' is 1-7.5% by weight; and the content of monomer D' is 1-7.5% by weight.

[0055] The monomer A' is The monomer B' The monomer C' is The monomer D' is

[0056] Wherein, R1 and R2 are H or methyl, M1 is hydrogen or alkali metal; R3 and R4 are each independently hydrogen or C4-C18 alkyl; 1≤n1≤4, 5≤n2≤19, and n1 and n2 are integers, for example, n1 can be 1, 2, 3 or 4; n2 can be 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 or 19.

[0057] In some embodiments of the present invention, R1 is H, R2 is H, R3 is hexyl, R4 is hexyl, M1 is Na, n1 is 2, and n2 is 9.

[0058] In some embodiments of the present invention, R1 is H, R2 is H, R3 is octyl, R4 is octyl, M1 is Na, M is Na, n1 is 3, and n2 is 15.

[0059] In some embodiments of the present invention, R1 is H, R2 is H, R3 is decyl, R4 is decyl, M1 is Na, n1 is 7, and n2 is 17.

[0060] In some embodiments of the present invention, R1 is H, R2 is H, R3 is dodecyl, R4 is dodecyl, M1 is Na, n1 is 3, and n2 is 15.

[0061] In some embodiments of the present invention, R1 is H, R2 is methyl, R3 is hexadecyl, R4 is hexadecyl, M1 is H, n1 is 3, and n2 is 15.

[0062] In this invention, the method may further include a hydrolysis step, in which the structural unit A provided by monomer A' is partially hydrolyzed into structural unit B. In this case, monomer B' may not need to be introduced into the alkenyl monomer solution. Alternatively, the method may exclude the hydrolysis step, in which case monomer B' may be introduced into the alkenyl monomer solution to obtain a polymer having structural unit B. It is understood that monomer B' can be introduced into the alkenyl monomer solution while the hydrolysis step is performed, provided that the following requirements are met under preferred conditions. Preferably, the content of monomer B' in the alkenyl monomer solution is such that the content of structural unit B in the polymer and the content of structural unit I satisfy the following requirements: structural unit I may not contain structural unit B, in which case the content of structural unit B is 0% by weight of the content of structural unit I, and the content of structural unit A is 100% by weight of the content of structural unit I. Preferably, structural unit I contains structural unit B, in which case the content of monomer B' in the alkenyl monomer solution is such that the content of structural unit B' in the polymer is 6-35% by weight, preferably 8-30% by weight; and the content of structural unit A is 65-94% by weight, preferably 70-92% by weight of the weight of structural unit I.

[0063] In this invention, the weight ratio of the alkenyl monomer to the solvent in the alkenyl monomer solution is 0.15-0.6:1. Preferably, the solvent in the alkenyl monomer solution is water, more preferably deionized water.

[0064] Preferably, the solution polymerization reaction is carried out under an inert atmosphere, more preferably under a nitrogen atmosphere. More preferably, the conditions for the solution polymerization reaction include: a temperature of 0-30°C, an initial pH of 5-12, and a time of 4-10 hours.

[0065] In this invention, the aforementioned pH value can be obtained by adding a pH adjuster to the polymerization system. The pH adjuster used to adjust the pH value can be any pH adjuster commonly used in the art, such as a base. The base can be a base containing an alkali metal element, such as sodium hydroxide and / or potassium hydroxide.

[0066] In this invention, the polymerization initiation method can be at least one of photoinitiation, thermal initiation, radiation initiation, and redox initiation. The photoinitiator is 2-hydroxy-2,2-dimethylacetophenone and / or 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylacetophenone.

[0067] In this invention, the amount of initiator used is the conventional amount. Those skilled in the art can select the initiator and the amount of initiator according to the actual situation. Preferably, the mass of the initiator is 0.0001-0.4% by weight of the total mass of the alkenyl monomer.

[0068] Preferably, the initiator is at least one of an azo initiator and a redox initiator; more preferably, it is an azo initiator and a redox initiator. In this invention, the initiator can be a compound commonly used in the art for initiating monomer free radical polymerization or copolymerization reactions.

[0069] In this invention, the amount of the azo initiator is the conventional amount. Those skilled in the art can select the azo initiator and its amount according to the actual situation. Preferably, the amount of the azo initiator is 0.0001-0.1% by weight of the total mass of the alkenyl monomer.

[0070] In this invention, the azo initiator is an aqueous solution with a mass concentration of 0.5-5%, and the amount of the azo initiator is the mass of the solute.

[0071] Preferably, the azo initiator is a water-soluble azo initiator, preferably at least one of 2,2'-azobis(2-amidinylpropane) dihydrochloride, 2,2'-azobis(2-imidazolinepropane) dihydrochloride, and 4,4'-azobis(4-cyanopentanoic acid).

[0072] In this invention, the amount of redox initiator used is the conventional amount. Those skilled in the art can select the redox initiator and its amount according to the actual situation. Preferably, the mass of the redox initiator is 0.0002-0.3% by weight of the total mass of the alkenyl monomer.

[0073] Preferably, the redox initiator includes an oxidant and a reducing agent.

[0074] In this invention, the amounts of oxidant and reducing agent are conventional. Those skilled in the art can select the amounts of oxidant and reducing agent according to the actual situation. Preferably, the mass ratio of oxidant to reducing agent is 0.1-1.5:1.

[0075] In this invention, the oxidant is an aqueous solution with a mass concentration of 0.5-5%, and the reducing agent is an aqueous solution with a mass concentration of 0.5-5%. The amounts of the oxidant and reducing agent are the mass of the solute.

[0076] More preferably, the reducing agent is at least one of inorganic reducing agents and organic reducing agents.

[0077] More preferably, the inorganic reducing agent is at least one selected from ferrous sulfate, ferrous ammonium sulfate, cuprous chloride, sodium thiosulfate, potassium thiosulfate, rongalite (sodium formaldehyde sulfoxylate), and sulfites.

[0078] More preferably, the sulfite is one of potassium sulfite, sodium sulfite, ammonium bisulfite, potassium bisulfite, and sodium bisulfite, and most preferably at least one of potassium bisulfite and sodium bisulfite.

[0079] More preferably, 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.

[0080] More preferably, the oxidant is at least one selected from benzoyl peroxide, hydrogen peroxide, tert-butyl hydroperoxide, 2,5-dimethyl-2,5-bis(hydrogen peroxide)hexane, and persulfate.

[0081] More preferably, at least one of ammonium persulfate, sodium persulfate, and potassium persulfate is used, and most preferably at least one of potassium persulfate and ammonium persulfate.

[0082] Preferably, the solution polymerization reaction further includes being carried out in the presence of a complexing agent.

[0083] In this invention, the complexing agent is used to reduce interference from impurities during the polymerization process and further increase the molecular weight. The amount of the complexing agent used is conventional; those skilled in the art can select the complexing agent and its amount according to actual conditions. Preferably, the amount of complexing agent added is 0.01-0.1% by weight of the total weight of the alkenyl monomer, more preferably 0.02-0.05% by weight.

[0084] Preferably, the complexing agent is at least one of disodium ethylenediaminetetraacetate (EDTA-2Na), sodium aminotriacetate, and diethylenetriaminepentacarboxylate; more preferably, the diethylenetriaminepentacarboxylate is pentasodium diethylenetriaminepentacarboxylate.

[0085] More preferably, the method further includes at least one of the following operations: granulation, hydrolysis or non-hydrolysis, drying, pulverization and sieving of the obtained product.

[0086] In this invention, the polymer prepared above is generally in gel form, and can be optionally granulated according to actual needs.

[0087] Preferably, the hydrolysis reaction is carried out under alkaline conditions. In this invention, when the initial pH of the polymerization reaction is high enough to maintain an alkaline environment during hydrolysis, it is not necessary to add alkali metal hydroxides to achieve an alkaline environment.

[0088] More preferably, the alkaline conditions are achieved by adding an alkali metal hydroxide.

[0089] In this invention, there is no particular limitation on the amount of alkali metal hydroxide added. Those skilled in the art can adjust it according to the needs of the reaction. Preferably, the amount of alkali metal hydroxide is 0.04-0.3g relative to each gram of monomer A'.

[0090] In this invention, the alkali metal hydroxide is a common one in the art that can provide alkaline conditions. Those skilled in the art can select the alkali metal hydroxide according to the actual situation. Preferably, the alkali metal hydroxide is NaOH and / or KOH.

[0091] The method for preparing the polymer according to the present invention may further include a hydrolysis step, wherein the hydrolysis results in a degree of hydrolysis of the polymer of 10-40%. "Degree of hydrolysis" refers to the percentage of the amount of structural unit A hydrolyzed into structural unit B, corresponding to the percentage of the molar amount of structural unit B relative to the total molar amount of structural unit A and structural unit B.

[0092] Preferably, the hydrolysis conditions include a temperature of 70-90℃ and a time of 2-24h.

[0093] According to a particularly preferred embodiment of the present invention, the structure of the compound is as follows:

[0094]

[0095] Where 1≤n1≤4, 15≤n2≤17, and n1 and n2 are integers.

[0096] According to a particularly preferred embodiment of the present invention, an acrylamide polymer with oil displacement function and a method for preparing the same include:

[0097] 1) Add monomers C' and D' to the aqueous solution and stir thoroughly to obtain a functional monomer mixture.

[0098] 2) Add acrylamide and / or monomer B' to the aqueous solution and stir to dissolve completely to obtain an acrylamide monomer solution.

[0099] 3) Add the functional monomer mixture to the acrylamide monomer solution, stir evenly to obtain the monomer mixture, adjust the temperature to 0℃ to 30℃, and adjust the pH to 5-12.

[0100] 4) After pouring the monomer mixture into the reactor, inert gas is introduced, followed by the addition of complex, azo, and redox initiator in sequence. Nitrogen is then introduced to ensure uniform mixing. After initiating polymerization, the reactor is sealed to carry out the reaction and obtain the polymer colloid.

[0101] 5) The colloid is removed and then granulated, hydrolyzed or not hydrolyzed, dried, pulverized and sieved to obtain an acrylamide copolymer.

[0102] A sixth aspect of the present invention provides an acrylamide polymer with oil displacement effect, characterized in that the polymer is prepared by the method described above.

[0103] The seventh aspect of the present invention provides an application of the above-mentioned polymer in oil reservoir development as at least one of a modifier, oil displacement agent, profile improver, and viscosity reducer.

[0104] The present invention will be described in detail below through embodiments. In the following embodiments,

[0105] Unless otherwise specified, all raw materials are commercially sourced.

[0106] The raw materials for preparing monomer D' were 6-hydroxytetrahydroquinoline, acryloyl chloride, ethylene glycol, diethylene glycol, triethylene glycol, bromodecane, bromohexadecane, bromooctadecane, pyridine, and thionyl chloride, which were purchased from Sigma-Aldrich.

[0107] Acrylamide crystals were purchased from Shandong Nuoer Biotechnology Co., Ltd.

[0108] N,N-dihexylacrylamide, N,N-dioctylacrylamide, N,N-didecylacrylamide, N,N-di(dodecyl)acrylamide, and N,N-di(hexadecyl)acrylamide in monomer C' are commercially available from Inokai Technology Co., Ltd.

[0109] The testing method is as follows:

[0110] 1) The residual monomer content of the polymer was determined with reference to the enterprise standard Q / SH1020 1572-2017 "Polyacrylamide for Oil Displacement" of China Petrochemical Corporation Shengli Oilfield Administration Bureau.

[0111] 2) Apparent viscosity was measured using a Brookfield viscometer in simulated water with a temperature of 20-85℃ and a mineralization of 5000-30000 mg / L.

[0112] 3) For interfacial tension testing, refer to the "rotation drop method" in the standard "SY / T 5370-2018 Method for Determination of Surface and Interfacial Tension" to measure the interfacial tension of the sample at 25℃.

[0113] 4) The viscosity-average molecular weight is calculated using the formula M = ([η] / K) according to the method 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.

[0114] 5) The method for determining water-insoluble matter includes the following steps:

[0115] ① Rinse the 25μm stainless steel filter screen with distilled water, place it in a dry weighing bottle, and dry it in a constant temperature drying oven at 120±2℃ for 2 hours.

[0116] ② Weigh 2.5g of sample, accurate to 0.0001g, and record it as W. Weigh 500g of 1000mg / L sodium chloride saline solution into an 800mL beaker to prepare a 5000mg / L polymer solution.

[0117] ③ Take out the weighing bottle, put it in a desiccator to cool for 30 minutes, and then weigh it to an accuracy of 0.0001g, which is recorded as W1.

[0118] ④ Insert the filter screen into the Gelman 2220 stainless steel aluminum membrane holder and connect it to the 600 mL Lilipore filter cartridge. Pour in the prepared 5000 mg / L polymer solution and filter under 0.2 MPa pressure. Rinse the beaker, stirring rod, and inner wall of the filter cartridge 3 to 4 times with about 500 mL of distilled water, and continue filtering the water.

[0119] ⑤ Remove the filter screen from the holder and place it in the weighing bottle from step ①. Dry it in a constant temperature drying oven at 120±2℃ for 2 hours. Remove the weighing bottle from the oven, place it in a desiccator to cool for 30 minutes, and then weigh it to an accuracy of 0.0001g. Record this as W2.

[0120] The formula for calculating insoluble matter is: Insoluble matter content = (W2 - W1) / W × 100%. Where W2 is the mass of (filter + insoluble matter + weighing bottle) in g; W1 is the mass of (filter + weighing bottle) in g; and W is the sample mass in g.

[0121] Example 1

[0122] (1) Monomer D' and its preparation method

[0123] 6-Hydroxytetrahydroquinoline (14.919 g, 100 mmol) was added to a dry three-necked flask and dissolved in 250 mL of anhydrous acetone. Potassium carbonate (14.511 g, 105 mmol) was then added, and the mixture was stirred at 25°C for 30 minutes. The entire system was then cooled to 0°C in an ice-water bath, and acryloyl chloride (9.956 g, 110 mmol) was slowly added dropwise while maintaining a constant temperature. After the addition was complete, the temperature was allowed to rise slowly to 25°C and stirred overnight. After the reaction was complete, the reaction mixture was quenched dropwise with water. The reaction product was extracted with diethyl ether (75 mL × 3), and the organic phase was dried over Na₂SO₄. The product was then recrystallized (using a mixture of n-hexane and dichloromethane in a 4:1 volume ratio) to obtain a white solid, IM₁ (14.633 g, 72 mmol).

[0124] At room temperature (25°C), diethylene glycol (25.469 g, 240 mmol) was added, followed by dissolution in 250 mL of anhydrous tetrahydrofuran. After complete dissolution, sodium hydride was added in three portions, totaling 6.8 g. The reaction was allowed to proceed for 30 minutes, followed by slow dropwise addition of bromodecane (55.295 g, 250 mmol). 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 (33.016 g, 134 mmol). A certain amount of pyridine (15.82 g, 200 mmol) was added, followed by slow dropwise addition of excess SOCl2 (23.792 g, 200 mmol). 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 weakly alkaline, and the mixture was washed five times with water. After rotary evaporation and drying, intermediate IM2 (19.862 g, 75 mmol) was obtained.

[0125] IM1 (14.633 g, 72 mmol) was dissolved in tetrahydrofuran (200 mL), potassium carbonate (11.056 g, 80 mmol) was added, and the mixture was stirred until homogeneous. The mixture was then heated to 75 °C, and intermediate IM2 (19.862 g, 75 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. The reaction system was then quenched with water, and the pH of the mixture was adjusted to 3 with dilute hydrochloric acid solution. The reaction product was extracted with diethyl ether (75 mL × 3), washed repeatedly with saturated sodium chloride, dried over Na2SO4, and recrystallized after rotary evaporation (the recrystallization solvent was a mixture of dichloromethane and petroleum ether in a volume ratio of 4:1) to obtain compound M1 (13.095 g, 41 mmol).

[0126] The reaction process is as follows: (1)

[0128] (2)

[0130] (3)

[0132]

[0133] The structural identification of M1 is as follows:

[0134] 1H NMR (300MHz, CDCl3) δ: 7.66 (dd, 1H), 6.99 (s, 1H), 6.84 (dd, 1H), 6.49 (t, 1H), 6.09 (dd, 1H), 5.75 (dd, 1H), 4.32(t, 2H), 3.78(t, 2H), 3.45-3.55(m, 6H), 3.19(t, 2H), 2.80(t, 2H), 1.80(m, 2H), 1.05(t, 3H).

[0135] 13 C NMR (75MHz, CDCl3) δ: 161.8, 153.2, 131.3, 130.2, 126.8, 117.1, 111.9, 111.3, 70.5, 70.2, 69.4, 66.7, 44.7, 27.4, 22.4, 15.2.

[0136] The results show that M1 has the structure shown in equation (1), where n1 = 2 and n2 = 9.

[0137] (2) Acrylamide polymers with oil displacement effect and their preparation methods

[0138] Add 1g of N,N-dihexylacrylamide and 4g of monomer D'(M1) to 40g of deionized water, and stir until homogeneous to obtain a functional monomer solution. Take 45g of acrylamide monomer and add it to 150g of water, stir until homogeneous, and then add it to the functional monomer solution. Make up the total weight with deionized water to 300g, adjust the pH to 6, and control the initial temperature at 0℃. Nitrogen gas was bubbled into the system for 20 minutes to remove oxygen. Then, 0.02 g of EDTA-2Na, 1 g of 0.25 wt% aqueous solution of 2,2-azobis(2-amidinepropane) dihydrochloride, 3 g of 0.2 wt% aqueous solution of ammonium persulfate, and 1 g of 0.6 wt% aqueous solution of sodium bisulfite were added to initiate polymerization. After the system became viscous, nitrogen bubbling was stopped, and the reaction continued for 4 hours. After polymerization was completed, the resulting colloid was granulated, and 5.2 g of sodium hydroxide was added to hydrolyze it at 70°C for 8 hours. The granules were then dried at 60°C until the solid content reached more than 89 wt%. The granules were then pulverized and sieved to obtain a 20-80 mesh polymer powder product.

[0139] The obtained polymer has a viscosity-average molecular weight of 11 million.

[0140] Based on the amount of feed, the resulting polymer contains structural units A, B, C, and D, with structural unit A accounting for 71.5% by weight, structural unit B accounting for 18.5% by weight, structural unit C accounting for 2.0% by weight, and structural unit D accounting for 8% by weight.

[0141] The residual monomer content, apparent viscosity, and interfacial tension of a 2000 mg / L polymer solution in simulated brine at 30℃ and 10000 mg / L mineralization, at 80℃ and 10000 mg / L mineralization, and at 80℃ and 20000 mg / L mineralization were determined. The results are shown in Table 1.

[0142] Example 2

[0143] (1) Monomer D' and its preparation method

[0144] At room temperature (25°C), triethylene glycol (36.041 g, 240 mmol) was added, followed by dissolution in 250 mL of anhydrous tetrahydrofuran. After complete dissolution, sodium hydride was added in five portions, totaling 7.4 g. The reaction was allowed to proceed for 30 minutes, followed by slow dropwise addition of hexadecane (85.495 g, 280 mmol). After the addition was complete, the reaction was continued for 3 hours. After the reaction was complete, the reaction system was quenched with water, and the solid was removed by filtration. Unreacted hexadecane was removed by vacuum distillation. The mixture was cooled to room temperature to obtain an intermediate (52.445 g, 140 mmol). A certain amount of pyridine (14.238 g, 180 mmol) was added, followed by slow dropwise addition of excess SOCl2 (21.412 g, 180 mmol). After the addition was complete, the mixture was reacted at 70°C for 10 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 weakly alkaline, and the mixture was washed six times with water. After rotary evaporation and drying, intermediate IM3 (31.444 g, 80 mmol) was obtained.

[0145] IM1 (14.633 g, 72 mmol) was dissolved in tetrahydrofuran (200 mL), potassium carbonate (11.747 g, 85 mmol) was added, and the mixture was stirred until homogeneous. The mixture was then heated to 75 °C, and intermediate IM2 (31.444 g, 80 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. The reaction system was then quenched with water, and the pH of the mixture was adjusted to 3 with dilute hydrochloric acid solution. The reaction product was extracted with diethyl ether (75 mL × 3), washed repeatedly with saturated sodium chloride, dried over Na2SO4, and recrystallized after rotary evaporation (the recrystallization solvent was a mixture of dichloromethane and petroleum ether in a volume ratio of 4:1) to obtain compound M2 (13.811 g, 38 mmol).

[0146] The reaction process is as follows: (1)

[0148] (2)

[0150]

[0151] The structural identification of M2 is as follows:

[0152] 1 H NMR (300MHz, CDCl3) δ: 7.64 (dd, 1H), 7.00 (s, 1H), 6.83 (dd, 1H), 6.47 (t, 1H), 6.08 (dd, 1H), 5.73 (dd, 1 H), 4.31 (t, 2H), 3.76 (t, 2H), 3.42-3.52 (m, 10H), 3.16 (t, 2H), 2.77 (t, 2H), 1.79 (m, 2H), 1.04 (t, 3H).

[0153] 13 C NMR (75MHz, CDCl3) δ: 161.6, 153.1, 131.1, 130.0, 126.7, 116.8, 111.8, 111.2, 70.3, 69.9, 66.5, 44.6, 27.2, 22.3, 15.1.

[0154] The results show that M2 has the structure shown in equation (1), where n1 = 3 and n2 = 15.

[0155] (2) Acrylamide polymers with oil displacement effect and their preparation methods

[0156] Add 2.5g of N,N-dioctylacrylamide and 3g of monomer D'(M2) to 40g of deionized water, and stir until homogeneous to obtain a functional monomer solution. Take 57.5g 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 6.5, and control the initial temperature at 5℃. Nitrogen gas was bubbled into the system for 20 minutes to remove oxygen. Then, 0.04 g of EDTA-2Na, 1 g of 0.25 wt% aqueous solution of 2,2-azobis(2-amidinepropane) dihydrochloride, 3.5 g of 0.2 wt% aqueous solution of ammonium persulfate, and 1.2 g of 0.6 wt% aqueous solution of sodium bisulfite were added to the system to initiate polymerization. After the system became viscous, nitrogen bubbling was stopped, and the reaction continued for 4 hours. After polymerization was completed, the resulting colloid was granulated, and 8.1 g of sodium hydroxide was added to hydrolyze it at 80°C for 6 hours. The granules were then dried at 60°C until the solid content reached more than 89 wt%. The granules were then pulverized and sieved to obtain a 20-80 mesh polymer powder product.

[0157] The obtained polymer has a viscosity-average molecular weight of 13.8 million.

[0158] Based on the amount of feed, the resulting polymer contains structural units A, B, C, and D, with structural unit A accounting for 68.4% by weight, structural unit B accounting for 22.8% by weight, structural unit C accounting for 4.0% by weight, and structural unit D accounting for 4.8% by weight.

[0159] The residual monomer content, apparent viscosity, and interfacial tension of a 2000 mg / L polymer solution in simulated brine at 30℃ and 10000 mg / L mineralization, at 80℃ and 10000 mg / L mineralization, and at 80℃ and 20000 mg / L mineralization were determined. The results are shown in Table 1.

[0160] Example 3

[0161] (1) Monomer D' and its preparation method

[0162] At room temperature (25°C), ethylene glycol (15.518 g, 250 mmol) was added, followed by dissolution in 250 mL of anhydrous tetrahydrofuran. After complete dissolution, sodium hydride was added in four portions, totaling 7.2 g. The reaction was allowed to proceed for 30 minutes, followed by slow dropwise addition of bromooctadecane (93.352 g, 280 mmol). 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 bromooctadecane was removed by vacuum distillation. The mixture was cooled to room temperature to obtain an intermediate (47.183 g, 150 mmol). A certain amount of pyridine (14.238 g, 180 mmol) was added, followed by slow dropwise addition of excess SOCl2 (23.792 g, 200 mmol). After the addition was complete, the mixture was reacted at 70°C for 10 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 weakly alkaline, and the mixture was washed five times with water. After rotary evaporation and drying, intermediate IM3 (28.305 g, 85 mmol) was obtained.

[0163] IM1 (14.633 g, 72 mmol) was dissolved in tetrahydrofuran (200 mL), potassium carbonate (12.438 g, 90 mmol) was added, and the mixture was stirred until homogeneous. The mixture was then heated to 75 °C, and intermediate IM4 (28.305 g, 85 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. The reaction system was then quenched with water, and the pH of the mixture was adjusted to 3 with dilute hydrochloric acid solution. The reaction product was extracted with diethyl ether (75 mL × 3), washed repeatedly with saturated sodium chloride, dried over Na2SO4, and recrystallized after rotary evaporation (the recrystallization solvent was a mixture of dichloromethane and petroleum ether in a volume ratio of 4:1) to obtain compound M3 (12.391 g, 45 mmol).

[0164] The reaction process is as follows: (1)

[0166] (2)

[0168]

[0169] The structural identification of M3 is as follows:

[0170] 1 H NMR (300MHz, CDCl3) δ: 7.63 (dd, 1H), 6.97 (s, 1H), 6.82 (dd, 1H), 6.46 (t, 1H), 6.07 (dd, 1H), 5.72 (d d, 1H), 4.30 (t, 2H), 3.74 (t, 2H), 3.45 (m, 2H), 3.17 (t, 2H), 2.76 (t, 2H), 1.77 (m, 2H), 1.03 (t, 3H).

[0171] 13 C NMR (75MHz, CDCl3) δ: 161.4, 153.0, 130.9, 130.1, 126.6, 116.9, 111.7, 110.9, 69.6, 69.2, 66.4, 44.4, 27.1, 22.2, 15.0.

[0172] The results show that M3 has the structure shown in equation (1), where n1 = 1 and n2 = 17.

[0173] (2) Acrylamide polymers with oil displacement effect and their preparation methods

[0174] Add 2g of N,N-didecylacrylamide and 4g of monomer D'(M3) to 40g of deionized water, and stir until homogeneous to obtain a functional monomer solution. Take 68g 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, 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 0.25 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 0.6 wt% aqueous solution of sodium bisulfite were added to initiate polymerization. After the system became viscous, nitrogen bubbling was stopped, and the reaction continued for 4 hours. After polymerization was completed, the resulting colloid was granulated, 9.62 g of sodium hydroxide was added, and the mixture was hydrolyzed at 75°C for 10 hours. It was then dried at 60°C until the solid content reached more than 89 wt%. The product was then pulverized and sieved to obtain a 20-80 mesh polymer powder.

[0175] The obtained polymer has a viscosity-average molecular weight of 13 million.

[0176] Based on the amount of feed, the resulting polymer contains structural units A, B, C, and D, with structural unit A accounting for 68.8% by weight, structural unit B accounting for 23.1% by weight, structural unit C accounting for 2.7% by weight, and structural unit D accounting for 5.4% by weight.

[0177] The residual monomer content, apparent viscosity, and interfacial tension of a 2000 mg / L polymer solution in simulated brine at 30℃ and 10000 mg / L mineralization, at 80℃ and 10000 mg / L mineralization, and at 80℃ and 20000 mg / L mineralization were determined. The results are shown in Table 1.

[0178] Example 4

[0179] Add 1.5g N,N-bis(dodecyl)acrylamide and 3.5g monomer D' (prepared according to step (1) in Example 2) to 40g deionized water, and stir until homogeneous to obtain a functional monomer solution. Take 70g acrylamide and 10g sodium acrylate and add them to 150g water, stir until homogeneous, and then add them to the functional monomer solution. Add deionized water to make up to a total weight of 300g, adjust the pH to 6, and control the initial temperature at 15℃. Nitrogen gas was bubbled into the system for 20 minutes to remove oxygen. Then, 0.03 g of EDTA-2Na, 1 g of 0.25 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 0.6 wt% aqueous solution of sodium bisulfite were added to the system to initiate polymerization. After the system became viscous, nitrogen bubbling was stopped, and the reaction continued for 4 hours. After polymerization was completed, the resulting colloid was granulated, dried at 60°C until the solid content reached more than 89 wt%, pulverized, and sieved to obtain a 20-80 mesh polymer dry powder product.

[0180] The obtained polymer has a viscosity-average molecular weight of 9.6 million.

[0181] Based on the amount of feed, the resulting polymer contains structural units A, B, C and D, with structural unit A accounting for 82.4% by weight, structural unit B accounting for 11.8% by weight, structural unit C accounting for 1.8% by weight and structural unit D accounting for 4.1% by weight.

[0182] The residual monomer content, apparent viscosity, and interfacial tension of a 2000 mg / L polymer solution in simulated brine at 30℃ and 10000 mg / L mineralization, at 80℃ and 10000 mg / L mineralization, and at 80℃ and 20000 mg / L mineralization were determined. The results are shown in Table 1.

[0183] Example 5

[0184] Add 3g of N,N-bis(hexadecyl)acrylamide and 2g of monomer D' (prepared according to step (1) in Example 2) to 40g of deionized water, and stir until homogeneous to obtain a functional monomer solution. Take 45g of acrylamide and 5g of methacrylic acid and add them to 150g of water, stir until homogeneous, and then add them to the functional monomer solution. Add deionized water to make up to a total weight of 300g, adjust the pH value to 6, and control the initial temperature at 15℃. Nitrogen gas was bubbled into the system for 20 minutes to remove oxygen. Then, 0.03 g of EDTA-2Na, 1 g of 0.25 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 0.6 wt% aqueous solution of sodium bisulfite were added to the system to initiate polymerization. After the system became viscous, nitrogen bubbling was stopped, and the reaction continued for 4 hours. After polymerization was completed, the resulting colloid was granulated, dried at 60°C until the solid content reached more than 89 wt%, pulverized, and sieved to obtain a 20-80 mesh polymer dry powder product.

[0185] The obtained polymer has a viscosity-average molecular weight of 8.4 million.

[0186] Based on the amount of feed, the resulting polymer contains structural units A, B, C, and D, with structural unit A accounting for 81.8% by weight, structural unit B accounting for 9.1% by weight, structural unit C accounting for 5.5% by weight, and structural unit D accounting for 3.6% by weight.

[0187] The residual monomer content, apparent viscosity, and interfacial tension of a 2000 mg / L polymer solution in simulated brine at 30℃ and 10000 mg / L mineralization, at 80℃ and 10000 mg / L mineralization, and at 80℃ and 20000 mg / L mineralization were determined. The results are shown in Table 1.

[0188] Comparative Example 1

[0189] Similar to Example 1, except that monomer D was not added. After obtaining the polymer dry powder, the resulting polymer contained structural unit A, structural unit B and structural unit C, calculated based on the amount of feed, wherein the content of structural unit A was 77.8% by weight, the content of structural unit B was 20.0% by weight, and the content of structural unit C was 2.2% by weight.

[0190] The residual monomer content, apparent viscosity, and interfacial tension of a 2000 mg / L polymer solution in simulated brine at 30℃ and 10000 mg / L mineralization, at 80℃ and 10000 mg / L mineralization, and at 80℃ and 20000 mg / L mineralization were determined. The results are shown in Table 1.

[0191] Table 1

[0192]

[0193] As shown in Table 1 above, the apparent viscosity of the polymers obtained in Examples 1-5 is higher than that in Comparative Example 1. Furthermore, the apparent viscosity of Examples 1-5 exhibits a temperature-increasing viscosity trend. When the mineralization is fixed at 10000 mg / L, the viscosity at 80°C is greater than that at 30°C, demonstrating a unique temperature-increasing viscosity. Simultaneously, at 80°C, even when the mineralization increases from 10000 mg / L to 20000 mg / L, the polymer solution still maintains a high viscosity, indicating good salt resistance at high mineralization levels. The introduction of the cyclic rigid long-chain monomer D enhances the rigidity of the polymer chain. Its steric hindrance effectively resists the compression of the polymer chain under high temperature and high salinity. Simultaneously, the nonpolar groups in the cyclic rigid long-chain monomer interact with the nonpolar groups in the N,N-dialkyl-substituted acrylamide, forming nonpolar aggregation regions in solutions with specific temperature and salinity. This results in the polymer exhibiting unique aqueous-phase temperature-induced thickening and salt-induced thickening properties under high temperature and high salinity. The water-insoluble matter data also shows that the water-insoluble matter in Examples 1-5 is <0.2%, meeting the solubility requirements of conventional polymers, indicating good solubility. Furthermore, the comparison of interfacial tension data shows that the polymers in Examples 1-5 have significantly better interfacial activity than the comparative examples, reducing interfacial tension and dispersing emulsified crude oil.

[0194] In this invention, conventional methods in the prior art can be used to test the content of each structural unit in the polymer, such as infrared spectroscopy, nuclear magnetic resonance, and the amount of monomers fed during polymerization. Preferably, the content of each structural unit in the polymer is determined by the amount of monomers fed. Specifically, the actual feeding ratio of each monomer participating in polymerization is determined by testing the content of unreacted monomers, thereby determining the content of each structural unit in the polymer. Furthermore, in this invention, when the content of each unreacted monomer in the polymer is tested to be 0.08% by weight or less, it indicates that all monomers have essentially participated in the polymerization reaction.

[0195] 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 structure of the compound is shown below: Equation (1) Where 1≤n1≤4, 5≤n2≤19, and n1 and n2 are integers.

2. The compound according to claim 1, wherein, 9≤n2≤17。 3. The use of the compound according to claim 1 or 2 in the preparation of acrylamide polymers with oil displacement function.

4. A method for preparing the compound according to claim 1 or 2, characterized in that, The method includes: (1) Under amidation reaction conditions, 6-hydroxy-1,2,3,4-tetrahydroquinoline was contacted with acryloyl chloride to carry out an amidation reaction; (2) Under alkylation reaction conditions, glycols and bromoalkanes are mixed and subjected to alkylation reaction; the glycol compound has the following structure: , 1≤n1≤4, and are integers; the structure of brominated alkanes is: , 5≤n2≤19, and are integers; (3) Under chlorination reaction conditions, the product of step (2) is contacted with thionyl chloride to carry out chlorination reaction; (4) Under the etherification reaction conditions, the compound obtained in step (1) and the compound obtained in step (3) are mixed and subjected to etherification reaction.

5. The method according to claim 4, wherein, The amount of acryloyl chloride used is 0.5-1.5 mol relative to 1 mol of 6-hydroxy-1,2,3,4-tetrahydroquinoline; And / or, relative to 1 mol of glycol, the amount of the bromoalkane is 0.8-1.5 mol; And / or, relative to 1 mol of the product of step (2), the amount of the substance of thionyl chloride is 0.8-2 mol; And / or, in step (4), the molar ratio of the product of step (1) to the product of step (3) is 1:0.9-1.5; And / or, the glycols are selected from ethylene glycol, diethylene glycol or triethylene glycol; And / or, the bromoalkane is selected from 1-bromohexane, 1-bromoheptane, 1-bromooctane, 1-bromononane, 1-bromodecane, 1-bromoundecane, 1-bromododecane, 1-bromotridecane, 1-bromotetradecane, 1-bromopentadecane, bromohexadecane, 1-bromoheptadecane, 1-bromooctadecane, or bromoeicosane; And / or, the amidation reaction conditions in step (1) include: a temperature of 0-35°C; and a time of 6-15 h; And / or, the alkylation reaction conditions in step (2) include: a temperature of 0-35°C; and a time of 1.5-6 h; And / or, the chlorination reaction conditions in step (3) include: a temperature of 60-90°C; and a time of 8-12 h; And / or, the etherification reaction conditions in step (4) include: a temperature of 60-90°C; and a time of 2-10 h; And / or, the method further includes: purifying at least one of the reaction products of steps (1), (3) and (4).

6. The method according to claim 5, wherein, The amount of acryloyl chloride used is 0.8-1.2 mol relative to 1 mol of 6-hydroxy-1,2,3,4-tetrahydroquinoline; And / or, relative to 1 mol of glycol, the amount of the bromoalkane is 0.9-1.3 mol; And / or, relative to 1 mol of the product of step (2), the amount of the substance of thionyl chloride is 1-1.8 mol; And / or, the amidation reaction conditions in step (1) include: a temperature of 10-25°C; and a time of 8-10 h; And / or, the alkylation reaction conditions in step (2) include: a temperature of 15-30°C; and a time of 2-4 hours; And / or, the chlorination reaction conditions in step (3) include: a temperature of 65-75°C; and a time of 10-11 h; And / or, the etherification reaction conditions in step (4) include: a temperature of 75-85°C and a time of 4-8h.

7. An acrylamide polymer with oil displacement properties, characterized in that, The polymer comprises structural unit I, structural unit C, and structural unit D, wherein structural unit I is structural unit A and / or structural unit B, and the content of structural unit I is 85-98% by weight, based on the weight of the polymer; the content of structural unit C is 1-7.5% by weight; and the content of structural unit D is 1-7.5% by weight. The structural unit A is The structural unit B is ; The structural unit C is The structural unit D is Wherein, R1 and R2 are H or methyl, M1 is hydrogen or alkali metal; R3 and R4 are each independently one of C4-C18 alkyl groups; 1≤n1≤4, 5≤n2≤19, and n1 and n2 are integers.

8. The polymer according to claim 7, wherein, The content of structural unit B is 6-35% by weight of the content of structural unit I. And / or, the C4-C18 alkyl group is a straight-chain alkyl group; And / or, the alkali metal is Na or K; And / or, 9≤n²≤17; And / or, R3 and R4 are each independently one of C6-C16 alkyl groups; And / or, the polymer has a viscosity-average molecular weight of 6-15 million.

9. The polymer according to claim 8, wherein, The content of structural unit B is 8-30% by weight of the content of structural unit I. And / or, the C4-C18 alkyl group is butyl, pentyl, hexyl, heptyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, or octadecyl; And / or, the polymer has a viscosity-average molecular weight of 8-14 million.

10. The polymer according to claim 9, wherein, The C4-C18 alkyl group is hexyl, heptyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, or octadecyl.

11. A method for preparing an acrylamide polymer with oil displacement properties, characterized in that, The method comprises: under solution polymerization conditions, in the presence of an initiator, causing an alkenyl monomer in a solution to undergo a polymerization reaction, characterized in that the alkenyl monomer comprises monomer I', monomer C', and monomer D'; monomer I' is monomer A' and / or monomer B', and based on the total weight of the alkenyl monomers in the solution, the content of monomer I' is 85-98% by weight; the content of monomer C' is 1-7.5% by weight; and the content of monomer D' is 1-7.5% by weight. The monomer A' is The monomer B' The monomer C' is The monomer D' is ; Wherein, R1 and R2 are H or methyl, M1 is hydrogen or alkali metal; R3 and R4 are each independently one of C4-C18 alkyl groups; 1≤n1≤4, 5≤n2≤19, and n1 and n2 are integers.

12. The method according to claim 11, wherein, The content of monomer B' in the alkenyl monomer solution is such that the content of structural unit B in the polymer is 6-35% by weight of the content of structural unit I; And / or, the C4-C18 alkyl group is a straight-chain alkyl group; And / or, the alkali metal is Na or K; And / or, 9≤n²≤17; And / or, R3 and R4 are each independently one of C6-C16 alkyl groups; And / or, the weight ratio of the alkenyl monomer to the solvent in the alkenyl monomer solution is 0.15-0.6:1; And / or, the solution polymerization reaction is carried out under an inert atmosphere; And / or, the conditions for the solution polymerization reaction include: a temperature of 0-30°C, an initial pH of 5-12, and a time of 4-10 h; And / or, the amount of the initiator is 0.0001-0.4% by weight of the total weight of the alkenyl monomer.

13. The method according to claim 12, wherein, The content of monomer B' in the alkenyl monomer solution is such that the content of structural unit B in the polymer is 8-30% by weight of the content of structural unit I. And / or, the C4-C18 alkyl group is butyl, pentyl, hexyl, heptyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, or octadecyl; And / or, the solvent in the alkenyl monomer solution is water; And / or, the solution polymerization reaction is carried out under a nitrogen atmosphere.

14. The method according to claim 11, wherein, The initiator is at least one of an azo initiator and a redox initiator.

15. The method according to claim 14, wherein, The azo initiator is a water-soluble azo initiator.

16. The method according to claim 15, wherein, The 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).

17. The method according to claim 15, wherein, The amount of the redox initiator is 0.0002-0.3% of the total weight of the alkenyl monomer.

18. The method according to claim 14, wherein, The redox initiator includes an oxidant and a reducing agent.

19. The method according to claim 18, wherein, The weight ratio of the oxidant to the reducing agent is 0.1-1.5:

1.

20. The method according to claim 18, wherein, The reducing agent is at least one of inorganic and organic reducing agents.

21. The method according to claim 20, wherein, The inorganic reducing agent is at least one of ferrous sulfate, ferrous ammonium sulfate, cuprous chloride, sodium thiosulfate, potassium thiosulfate, sodium hydroxide, and sulfites.

22. The method according to claim 21, wherein, The sulfite is one of potassium sulfite, sodium sulfite, ammonium bisulfite, potassium bisulfite, and sodium bisulfite.

23. The method according to claim 22, wherein, The sulfite is at least one of potassium bisulfite and sodium bisulfite.

24. The method of claim 20, 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.

25. The method according to claim 18, wherein, The oxidant is at least one selected from benzoyl peroxide, hydrogen peroxide, tert-butyl hydroperoxide, 2,5-dimethyl-2,5-bis(hydrogen peroxide)hexane, and persulfate.

26. The method of claim 25, wherein, The oxidant is at least one of ammonium persulfate, sodium persulfate, and potassium persulfate.

27. The method according to claim 26, wherein, The oxidant is at least one of potassium persulfate and ammonium persulfate.

28. The method according to claim 11, wherein, The monomer solution also contains a complexing agent.

29. The method according to claim 28, wherein, The amount of the complexing agent is 0.01-0.1% by weight of the total weight of the alkenyl monomer.

30. The method according to claim 29, wherein, The amount of the complexing agent is 0.02-0.05% of the total weight of the alkenyl monomer.

31. The method according to claim 28, wherein, The complexing agent is at least one of disodium ethylenediaminetetraacetate, sodium aminotriacetate, and diethylenetriaminepentacarboxylate.

32. The method according to claim 31, wherein, The diethylenetriamine pentacarboxylate is diethylenetriamine pentacarboxylate pentasodium.

33. The method according to any one of claims 11-32, wherein, The method further includes at least one of the following operations: granulation, hydrolysis or non-hydrolysis, drying, pulverization and sieving of the polymerization product.

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

35. The method according to claim 34, wherein, The alkaline conditions are achieved by adding an alkali metal hydroxide.

36. The method according to claim 35, wherein, The amount of the alkali metal hydroxide used is 0.04-0.3 g relative to each gram of monomer A'.

37. The method of claim 35, wherein, The alkali metal hydroxide is NaOH and / or KOH.

38. The method according to claim 34, wherein, Hydrolysis results in a degree of hydrolysis of the polymer of 10-40%.

39. The method according to claim 34, wherein, The hydrolysis conditions include a temperature of 70-90℃ and a time of 2-24h.

40. The use of the polymer according to any one of claims 7-10 as at least one of a modifier, displacement agent, profile improver, and viscosity reducer in oil reservoir development.

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