Double-tailed hydrophobic association polymer oil-displacing agent with benzene ring structure and preparation method of oil-displacing agent

Abstract

The invention relates to a double-tailed hydrophobic associated polymer oil-displacing agent with a benzene ring structure and a preparation method thereof. The oil-displacing agent is formed by copolymerizing three monomers, namely acrylamide, 2-allyl methylamino sodium ethanesulfonate and a hydrophobic monomer double-tailed long-chain alkyl methyl (p-3-carboxyl acrylamide benzyl) ammonium chloride with the benzene ring structure. The preparation method comprises the following steps: firstly adding distilled water, then adding acrylamide, 2-allyl methylamino sodium ethanesulfonate and a hydrophobic monomer double-tailed long-chain alkyl methyl (p-3-carboxyl acrylamide benzyl) ammonium chloride with a benzene ring structure, supplementing water, adjusting the total concentration, introducing N2 to remove oxygen, adding an initiator, and reacting at a certain temperature to prepare the terpolymer. The prepared polymer oil-displacing agent has good water solubility, temperature resistance and shearing resistance, shows good salt resistance in saline water with the mineralization degree larger than or equal to 30000 mg / L and shows a good oil-displacing effect in a heterogeneous core oil-displacing experiment, and the crude oil recovery rate can be increased by 10% or above.

Description

Technical Field

[0001] The present invention relates to an oil recovery auxiliary agent, in particular to a hydrophobic associating polymer oil-displacing agent containing a cyclic structure and a double-tailed hydrophobic group, specifically a double-tailed hydrophobic associating polymer oil-displacing agent with a benzene ring structure. The present invention also relates to a preparation method of the double-tailed hydrophobic associating polymer oil-displacing agent with a benzene ring structure. Background Art

[0002] About 60% of the crude oil in the already exploited reservoirs cannot be further exploited using conventional oil recovery technology. Polymer flooding is widely used due to its simple oil recovery mechanism, obvious oil recovery effect, relatively mature technology, simple oil recovery process, and convenient operation. It has been widely used in oil fields and other fields and has achieved significant water reduction and oil increase effects, playing an important role in stabilizing the production of old oil fields. However, as the conditions for oil reservoir exploitation become increasingly harsh, the partially hydrolyzed polyacrylamide (HPAM) currently used is difficult to apply to such reservoirs. In order to improve the temperature and salt resistance of polymers and meet the conditions of high temperature and high salt reservoirs, domestic and foreign scholars have developed many temperature and salt resistant polymers in recent years, among which hydrophobic associating polymers are one of the products. Hydrophobic associating water-soluble polymers are water-soluble polymers formed by introducing a very small amount of hydrophobic groups into the hydrophilic main chain of the polymer. In aqueous solution, the hydrophobic groups interact with each other to form a spatial network structure, showing good viscosity enhancement, temperature resistance, salt resistance and shear resistance (Chen Hong, Li Erxiao, Ye Zhongbin, et al. Interaction between hydrophobic associating polyacrylamide and gemini surfactants [J]. Acta Physico-Chimica Sinica, 2011, 27(3): 671-676.). At present, hydrophobic associating polymers have been used in some Class II and Class III reservoirs to a certain extent and have achieved good results.

[0003] Related patent literature: CN102391418A discloses a water-soluble hydrophobic associating polymer oil-displacing agent for oil reservoir flooding to enhance crude oil recovery and its synthesis method. It is water-soluble, increases the viscosity of the solution, and exhibits good temperature resistance, salt resistance and shear resistance. Its technical solution: The oil-displacing agent is a ternary polymer composed of acrylamide, sodium acrylate, and N, N-diallyl oleyl imide; the mass percentages of the monomers used are: AM 53.5-59.9, NaAA 40-45, and DNDA 0.1-1.5. The synthesis method thereof is as follows: the prepared DNDA is added into a flask, and then OP-10 emulsifier and water are added, and after stirring and emulsifying, AM, acrylic acid and NaOH are added to prepare a 10-25% solution, and the pH is adjusted to 7.5-11, and N2 is passed for 20 minutes, and then an initiator is added and N2 is passed for 10-20 minutes, and the reaction is carried out at 30-70°C for 4-12 hours; finally, the AM / NaAA / DNDA polymer is obtained by washing, crushing and drying. The polymer exhibits good temperature and salt resistance, can improve crude oil recovery rate, and is used for oil field reservoir flooding. CN102391849A discloses an imidazole polymer oil-displacing agent for oil field reservoir flooding to improve crude oil recovery rate and a synthesis method thereof. The technical scheme is as follows: the oil displacement agent is a ternary polymer composed of acrylamide AM, sodium acrylate NaAA, and N-allylimidazole NAI; the raw material components used are AM 63.5-70%, NaAA 28.7-36%, and NAI 0.5-1.3%. The synthesis method is as follows: firstly, the prepared NAI is added into a flask, and then AM, acrylic acid, emulsifier OP-10 and NaOH are added to prepare a solution with a total monomer mass concentration of 10-20%, and nitrogen is passed through for 30 minutes; then an initiator is added, and N2 is continuously passed through for 10-20 minutes, and the reaction is carried out at a temperature of 30-60°C for 4-12 hours; finally, the AM / NaAA / NAI ternary polymer is obtained by washing with anhydrous ethanol, crushing, and drying. The viscosity, temperature resistance, salt resistance, and shear resistance of the polymer are greatly increased, and the crude oil recovery rate can be well improved, and the polymer can be used for crude oil exploitation in oil fields. CN103641950A discloses an anionic hydrophobically associated partially hydrolyzed polyacrylamide. The preparation method of the anionic hydrophobically associated partially hydrolyzed polyacrylamide is to first prepare a hydrophobic monomer-octyl acrylate. Then, it is synthesized with anionic monomers 2-acrylamido-2-methylpropanesulfonic acid, acrylic acid and acrylamide to synthesize anionic hydrophobically associated partially hydrolyzed polyacrylamide. The anionic hydrophobically associated partially hydrolyzed polyacrylamide can be used as an oil displacement agent in the tertiary oil recovery process. Compared with existing polyacrylamide and hydrophobically associated polymers, anionic hydrophobically associated partially hydrolyzed polyacrylamide has better temperature resistance, salt resistance and shear resistance, and can be used as an tertiary oil recovery oil displacement agent to improve crude oil recovery, especially under high temperature and high salt conditions. CN103059217A discloses a temperature-resistant and salt-resistant hydrophobically associated polymer oil displacement agent and a preparation method.The preparation scheme is as follows: the mass is in grams, the monomer mass percentage is 57.0-59.8% acrylamide AM, 39.3-40.0% sodium acrylate NaAA, 0.1-0.2% N-allylphenylacetamide NAPA, and 0.1-3.5% N,N-dimethyl-N-allyl hexadecyl ammonium chloride AHAC; the preparation method is to add NAPA, AHAC and an emulsifier into a reactor, add water to emulsify completely; then add NaAA and AM, adjust the pH to 7, add an initiator, and after reaction, wash, crush, and dry to obtain a polymer product. The polymer has water solubility, high viscosity increasing ability, and heat resistance and shear resistance. The viscosity retention rate of a 0.1wt% solution at 100°C reaches 91.3%, and it can increase the recovery rate of simulated crude oil by 16.6%.

[0004] The hydrophobic associating polymer synthesized by the above technology has certain temperature and salt resistance, and has good viscosity increasing ability below the mineralization degree of 30000 mg / L, but its salt resistance is poor when the mineralization degree is ≥30000 mg / L. Summary of the invention

[0005] The purpose of the present invention is to provide a double-tailed hydrophobic associating polymer oil-displacing agent with a benzene ring structure, which has good performance, good viscosity increasing ability under high temperature and high salinity, and good shear resistance, can achieve a higher recovery rate, and can meet the technical requirements of a polymer oil-displacing agent with a wide range of uses on the market, thereby ensuring the smooth progress of oil production in high-temperature and high-salinity oil fields, and solving the problems that the existing hydrophobic associating polymers have poor temperature and salt resistance in brine with high salinity (mineralization ≥30000 mg / L), are easily hydrolyzed underground, and have a low crude oil recovery rate.

[0006] To this end, another object of the present invention is to provide a method for preparing a double-tailed hydrophobic associating polymer oil-displacing agent with a benzene ring structure.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0008] A (water-soluble) double-tailed hydrophobic associating polymer oil-displacing agent with a benzene ring structure, the technical scheme of which is that it is composed of acrylamide AM, 2-allylmethylaminoethylsulfonic acid sodium AMES-Na and a double-tailed long-chain alkylmethyl (p-3-carboxyacrylamide benzyl) ammonium chloride DC with a benzene ring structure hydrophobic monomer n MCABAC is copolymerized by three monomers, and the structural formula of the polymer oil displacement agent is as follows:

[0009]

[0010] In the above structural formula, x, y, and z are the molar percentage ranges of the structural units: x = 69.5% to 84.9%, y = 15% to 30%, z = 0.1% to 0.5%, x + y + z = 100%, wherein n = 8, 10, 12, or 14. The long-chain alkyl group is selected from alkanes with the same carbon number.

[0011] In the double-tailed hydrophobic associating polymer oil-displacing agent with a benzene ring structure, the molar fractions of each monomer are as follows (i.e., the oil-displacing agent is made of the following molar fractions of monomers): 69.5 to 84.9 parts of acrylamide AM, 15 to 30 parts of 2-allylmethylaminoethylsulfonic acid sodium AMES-Na, and a double-tailed long-chain alkylmethyl (p-3-carboxyacrylamide benzyl) ammonium chloride DC n MCABAC 0.1~0.5 parts.

[0012] The preparation method of the above-mentioned 2-allylmethylaminoethanesulfonic acid sodium AMES-Na comprises the following process steps: in a (500mL) three-necked flask equipped with a thermometer, a reflux condenser with a Soxhlet extractor and a magnetic rotor, adding an appropriate amount of anhydrous ethanol as a solvent, adding 65-95g of 2-chloroethylsulfonic acid sodium at room temperature (temperature is 23-25°C), then slowly adding 30-43g of N-methylallylamine under stirring, adding 0.15-0.21g of inhibitor methylhydroquinone, and charging 32-47g of an acid binding agent wrapped with filter paper into the Soxhlet extractor, raising the temperature to reflux, reacting at a constant temperature for 20-25 hours, and removing the solvent and excess N-methylallylamine by reduced pressure distillation using a rotary evaporator to obtain 2-allylmethylaminoethanesulfonic acid sodium AMES-Na.

[0013] The above hydrophobic monomer with benzene ring structure has double tail long chain alkyl methyl (p-3-carboxy acrylamide benzyl) ammonium chloride DC nThe preparation method of MCABAC comprises the following process steps: (1) adding an appropriate amount of anhydrous ethanol as a solvent to a three-necked flask (500 mL) equipped with a thermometer, a reflux condenser and a magnetic rotor, adding 90 to 130 g of a double-tailed long-chain alkylmethyl tertiary amine at room temperature (23 to 25° C.) and with magnetic stirring on, then slowly adding 30 to 45 g of p-aminobenzyl chloride under stirring, raising the temperature to reflux, reacting at constant temperature for 10 to 15 hours, removing the solvent by reduced pressure distillation using a rotary evaporator, and then recrystallizing using acetone to obtain double-tailed long-chain alkylmethyl (4-aminobenzyl) ammonium chloride; (2) adding 100 to 250 mL of anhydrous ethanol as a solvent to a three-necked flask (500 mL) equipped with a thermometer, a reflux condenser and a magnetic rotor, and then slowly adding 100 to 250 mL of anhydrous ethanol as a solvent to obtain double-tailed long-chain alkylmethyl (4-aminobenzyl) ammonium chloride; and (3) adding 100 to 250 mL of anhydrous ethanol as a solvent to a three-necked flask (500 mL) equipped with a thermometer, a reflux condenser and a magnetic rotor. 0mL) three-necked flask, add an appropriate amount of anhydrous ethanol as a solvent, add 70-110g of double-tailed long-chain alkylmethyl (4-aminobenzyl) ammonium chloride at room temperature (temperature is 23-25°C) and with magnetic stirring turned on, then slowly add 15-25g of maleic anhydride under stirring, raise the temperature to 60-70°C, and react at constant temperature for 6-8 hours to obtain a reaction solution, add a pH regulator to the reaction solution to adjust the pH value of the reaction solution to neutral, then use a rotary evaporator to remove the solvent under reduced pressure, and then use anhydrous ethanol to separate and purify, so as to obtain a hydrophobic monomer double-tailed long-chain alkylmethyl (p-3-carboxyacrylamide benzyl) ammonium chloride DC with a benzene ring structure. n MCABAC.

[0014] The preparation method of the double-tailed hydrophobic associating polymer oil-displacing agent with a benzene ring structure comprises the following process steps: firstly, 1000-1500 mole parts of distilled water are added into a reactor, and 69.5-84.9 mole parts of acrylamide AM, 15-30 mole parts of 2-allylmethylaminoethylsulfonic acid sodium AMES-Na, an emulsifier, a double-tailed long-chain alkyl methyl (p-3-carboxyacrylamide benzyl) ammonium chloride DC are added in sequence under stirring. n MCABAC 0.1-0.5 molar parts, and then distilled water is added to control the total mass percentage concentration of the reaction monomers to be between 15% and 30% (the total mass percentage concentration of the reaction monomers is the mass percentage concentration of the above three monomers combined, the same below), and after stirring evenly (stirring the solution until the solution is a nearly transparent homogeneous system), N2 is passed for 30-35 minutes, and then an initiator is added, and N2 is continued to be passed. The reaction is carried out under nitrogen protection at 30-60° C. for 4-10 hours. The above reaction monomers are the above three monomers; after the reaction, the obtained gel product is washed with anhydrous ethanol, and the product is crushed and dried to obtain AM / AMES / DC n MCABAC terpolymer, the terpolymer is a double-tailed hydrophobic associating polymer oil displacement agent with a benzene ring structure.

[0015] In the above technical scheme, the preferred technical scheme may be that the initiator is a composite initiator, including an oxidation-reduction system initiator and a water-soluble azo initiator. In the oxidation-reduction system initiator, the oxidant is potassium persulfate or ammonium persulfate, the reductant is sodium bisulfite, and the molar ratio of the oxidant to the reductant is 1:1 to 1.5; the water-soluble azo initiator is one or a combination of azobisisobutylamidine hydrochloride (V-50), azobisisobutylimidazoline hydrochloride (VA-044), and azobis(N-2-carboxyethyl-2-methylpropionamidine) hydrate (VA-057), and the ratio is arbitrary when combined; in the composite initiator, the mass ratio of the oxidation-reduction system initiator to the water-soluble azo initiator is 1:1 to 2.

[0016] In the above technical solution, the preferred technical solution can also be that the above hydrophobic monomer with a benzene ring structure has a double-tail long-chain alkyl methyl (p-3-carboxyacrylamide benzyl) ammonium chloride DC n In MCABAC, the long-chain alkyl group can be selected from decyl groups, and the double-tailed long-chain alkyl methyl tertiary amine is didecyl methyl tertiary amine; step (2) finally obtains didecyl methyl (p-3-carboxyacrylamide benzyl) ammonium chloride DC with a benzene ring structure. 10 MCABAC, see Example 1.

[0017] The above hydrophobic monomer with benzene ring structure has double tail long chain alkyl methyl (p-3-carboxy acrylamide benzyl) ammonium chloride DC n In MCABAC, the long-chain alkyl group can also be dodecyl, and the double-tail long-chain alkyl methyl tertiary amine is didodecyl methyl tertiary amine; step (2) finally obtains didodecyl methyl (p-3-carboxyacrylamide benzyl) ammonium chloride DC with a benzene ring structure. 12 MCABAC, see Example 2.

[0018] In the above technical scheme, a preferred technical scheme can also be that the acid binding agent can be potassium carbonate or sodium carbonate, etc.; the pH value adjusting agent can be a sodium hydroxide aqueous solution with a mass percentage concentration of 20%; the emulsifier can be hexadecyltrimethylammonium bromide, and the amount of hexadecyltrimethylammonium bromide added is 0.06% to 0.1% of the total mass of the reaction solution. The emulsifier can also be OP-10, etc.; the amount of initiator added is 0.05% to 0.2% of the total mass of the reaction monomers, and the total mass of the reaction monomers is the total mass of the three monomers described above.

[0019] Among the above technical solutions, a preferred technical solution may also be Embodiment 1 of the present invention.

[0020] The polymer oil displacement agent of the present invention is composed of acrylamide AM, 2-allylmethylaminoethylsulfonic acid sodium AMES-Na and a hydrophobic monomer with a benzene ring structure and a double-tailed long-chain alkylmethyl (p-3-carboxylacrylamide benzyl) ammonium chloride DC. n Preparation method: Add distilled water into the reactor, and then add acrylamide AM, 2-allylmethylaminoethylsulfonic acid sodium AMES-Na, emulsifier hexadecyltrimethylammonium bromide, hydrophobic monomer with benzene ring structure double-tail long-chain alkylmethyl (p-3-carboxyacrylamide benzyl) ammonium chloride DC. n MCABAC, then add distilled water, stir until it becomes a nearly transparent solution, pass nitrogen to deoxygenate, add initiator, and react at a certain temperature to obtain AM / AMES / DC n The MCABAC terpolymer is the polymer oil-displacing agent. The present invention introduces a double hydrophobic chain and a benzene ring structure into the polymer chain, thereby improving the viscosity-increasing ability and salt resistance of the polymer, and increases the rigidity of the molecular chain by introducing a ring structure, thereby improving the thermal stability and shear resistance of the polymer. Sulfonic acid groups are introduced into the molecular chain to improve the water solubility and salt resistance of the polymer, meeting the actual construction needs of injection water with a mineralization of ≥30000mg / L on site. The polymer oil-displacing agent prepared by the present invention has good water solubility, and shows good temperature and salt resistance in salt water with a mineralization of ≥30000mg / L. The oil displacement experiment shows a good oil displacement effect, and the crude oil recovery rate is increased by more than 10%.

[0021] Compared with the prior art, the present invention has the following effects: (1) the introduction of double hydrophobic long chains and benzene rings into the hydrophobic monomer greatly enhances the rigidity of the polymer molecular chain and increases the hydrophobic association between copolymer molecules, thereby greatly increasing the viscosity, shear resistance and rheological properties of the polymer, and greatly improving the temperature resistance of the polymer; (2) the introduction of sulfonic acid groups improves the salt resistance of the polymer; (3) the polymer exhibits good temperature resistance, salt resistance and shear thinning resistance, and effectively improves the crude oil recovery rate.

[0022] Referring to the experimental (test) part of the present invention below, in summary, the present invention provides a (water-soluble) double-tailed hydrophobic associating polymer oil-displacing agent with a benzene ring structure, which has good performance, good viscosity increasing ability at high temperature and high salinity, and good shear resistance, achieving a higher recovery rate, and can meet the technical requirements of polymer oil-displacing agents with a wide range of uses on the market, thereby ensuring the smooth progress of oil production in high-temperature and high-salinity oil fields, and solving the problems of poor temperature and salt resistance of existing hydrophobic associating polymers in brine with high salinity (mineralization ≥30000 mg / L), easy hydrolysis underground, and low crude oil recovery rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is the infrared spectrum of the copolymer (oil-displacing agent) synthesized (prepared) in Example 1 of the present invention.

[0024] Figure 2 Graph showing the relationship between the apparent viscosity of the copolymer (oil displacing agent) synthesized in Example 1 of the present invention and the change in concentration.

[0025] Figure 3 Graph showing the relationship between the apparent viscosity of the copolymer (oil displacing agent) synthesized in Example 1 of the present invention and the change in temperature.

[0026] Figure 4 The figure is a relationship diagram of the apparent viscosity of the copolymer (oil displacement agent) synthesized in Example 1 of the present invention as a function of the salinity.

[0027] Figure 5 Graph showing the relationship between the apparent viscosity of the copolymer (oil displacing agent) synthesized in Example 1 of the present invention and the shear rate.

[0028] Figure 6 This is a diagram of the oil displacement efficiency of the copolymer (oil displacement agent) synthesized in Example 1 of the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described in conjunction with the embodiments below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on this embodiment, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of the present invention.

[0030] Example 1: The (water-soluble) hydrophobic associating polymer oil-displacing agent with a benzene ring structure is prepared from the following monomers in molar fractions (copolymerized from three monomers): 78.46 parts of acrylamide AM, 21.17 parts of 2-allylmethylaminoethylsulfonic acid sodium AMES-Na, and a hydrophobic monomer with a benzene ring structure and a double-tailed long-chain alkylmethyl (p-3-carboxyacrylamidobenzyl) ammonium chloride DC n MCABAC 0.37 parts. The structural formula of the polymer oil displacement agent is as follows:

[0031]

[0032] In the above structural formula, x, y, and z are the molar percentage ranges of the structural unit: x=78.46%, y=21.17%, z=0.37%, x+y+z=100%, wherein n=8, 10, 12, or 14. In this embodiment, n=8. The above hydrophobic monomer with a benzene ring structure has a double-tailed long-chain alkylmethyl (p-3-carboxyacrylamide benzyl) ammonium chloride DC nIn MCABAC, the long-chain alkyl group is a decyl group, and the double-tailed long-chain alkyl methyl tertiary amine is a didecylmethyl tertiary amine; the following step (1) finally obtains didecylmethyl (4-aminobenzyl) ammonium chloride; the following step (2) finally obtains didecylmethyl (p-3-carboxyacrylamidobenzyl) ammonium chloride DC, a hydrophobic monomer with a benzene ring structure 10 MCABAC.

[0033] The preparation method of the above-mentioned 2-allylmethylaminoethanesulfonic acid sodium AMES-Na comprises the following process steps: adding 180 mL of anhydrous ethanol as a solvent to a 500 mL three-necked flask equipped with a thermometer, a reflux condenser with a Soxhlet extractor and a magnetic rotor, adding 77 g of sodium 2-chloroethylsulfonate at a temperature of 25° C., then slowly adding 35 g of N-methylallylamine under stirring, adding 0.18 g of methylhydroquinone as an inhibitor, and charging 38 g of potassium carbonate wrapped with filter paper into the Soxhlet extractor, raising the temperature to reflux, reacting at a constant temperature for 23 hours, and removing the solvent and excess N-methylallylamine by reduced pressure distillation using a rotary evaporator to obtain 2-allylmethylaminoethanesulfonic acid sodium AMES-Na.

[0034] The above hydrophobic monomer with benzene ring structure has double tail long chain alkyl methyl (p-3-carboxy acrylamide benzyl) ammonium chloride DC 10 The preparation method of MCABAC comprises the following process steps: (1) adding 200 mL of anhydrous ethanol as a solvent to a 500 mL three-necked flask equipped with a thermometer, a reflux condenser and a magnetic rotor, adding 90 g of didecylmethyl tertiary amine at a temperature of 25° C. and with magnetic stirring turned on, then slowly adding 35 g of p-aminobenzyl chloride under stirring, raising the temperature to reflux, reacting at constant temperature for 14 hours, removing the solvent by reduced pressure distillation using a rotary evaporator, and then recrystallizing using acetone to obtain didecylmethyl (4-aminobenzyl) ammonium chloride; (2) adding 18 0mL of anhydrous ethanol is used as a solvent, 85g of didecylmethyl (4-aminobenzyl) ammonium chloride is added under the condition of 25°C and magnetic stirring is turned on, and then 21g of maleic anhydride is slowly added under stirring, the temperature is raised to 70°C, and the reaction is carried out at a constant temperature for 7 hours to obtain a reaction solution, a pH regulator is added to the reaction solution to adjust the pH value of the reaction solution to neutral, the pH regulator is a sodium hydroxide aqueous solution with a mass percentage concentration of 20%, and then the solvent is removed by reduced pressure distillation using a rotary evaporator, and then separated and purified using anhydrous ethanol to obtain a hydrophobic monomer didecylmethyl (p-3-carboxyacrylamide benzyl) ammonium chloride DC with a benzene ring structure. 10 MCABAC.

[0035] The preparation method of the double-tailed hydrophobic associating polymer oil-displacing agent with a benzene ring structure comprises the following process steps: firstly, 1000 mole parts of distilled water are added into a reactor, and 78.46 mole parts of acrylamide AM, 21.17 mole parts of 2-allylmethylaminoethanesulfonic acid sodium AMES-Na, emulsifier hexadecyltrimethylammonium bromide (the amount of emulsifier hexadecyltrimethylammonium bromide added is 0.08% of the total mass of the reaction solution), hydrophobic monomer with a benzene ring structure didecylmethyl (p-3-carboxyacrylamidobenzyl) ammonium chloride DC are added in sequence under stirring. 10 MCABAC 0.37 mole parts, and then distilled water is added to control the total mass percentage concentration of the reaction monomers to 20%. After stirring evenly, N2 is passed through to deoxygenate for 30 minutes, and then 0.1% of the initiator of the total mass of the reaction monomers is added, and N2 is continued to be passed through, and the reaction is carried out under nitrogen protection at 45°C for 8 hours. The above reaction monomers are the three monomers mentioned above; after the reaction, the obtained gel product is washed with anhydrous ethanol, and the product is crushed and dried to obtain AM / AMES / DC 10 MCABAC terpolymer, the terpolymer is a double-tailed hydrophobic associating polymer oil-displacing agent with a benzene ring structure (that is, the polymer oil-displacing agent of the present invention).

[0036] The above-mentioned initiator is a composite initiator, including an oxidation-reduction system initiator and a water-soluble azo initiator. In the oxidation-reduction system initiator, the oxidant is potassium persulfate, the reductant is sodium bisulfite, and the molar ratio of the oxidant to the reductant is 1:1. The water-soluble azo initiator is azobisisobutylimidazoline hydrochloride (VA-044). In the composite initiator, the mass ratio of the oxidation-reduction system initiator to the water-soluble azo initiator is 1:1.6.

[0037] Preparation of comparative example: In order to facilitate the experimental part of the present invention, AM / AMES / DC 10 The MCABAC terpolymer is abbreviated as PAAD (ie, the polymer oil displacement agent of the present invention). Under the same conditions, acrylamide AM and acrylic acid AA are used to synthesize partially hydrolyzed polyacrylamide HPAM (comparative example).

[0038] Example 2: The hydrophobic associating polymer oil displacement agent with a benzene ring structure double tail of the present invention is prepared from the following monomers in molar fractions (copolymerized from three monomers): 81.22 parts of acrylamide AM, 18.51 parts of 2-allylmethylaminoethylsulfonic acid sodium AMES-Na, and 2-methyl-3-carboxy-acrylamide-benzyl long-chain alkyl methyl ammonium chloride DC n MCABAC 0.27 parts. The structural formula of the polymer oil-displacing agent is the same as that of Example 1.

[0039] In the above structural formula, x, y, and z are the molar percentage ranges of the structural unit: x=81.22%, y=18.51%, z=0.27%, x+y+z=100%, wherein n=8, 10, 12, 14. In this embodiment, n=10. The above hydrophobic monomer with a benzene ring structure has a double-tailed long-chain alkylmethyl (p-3-carboxyacrylamide benzyl) ammonium chloride DC n In MCABAC, the long-chain alkyl group is dodecyl, and the double-tail long-chain alkyl methyl tertiary amine is didodecyl methyl tertiary amine; the following step (1) finally obtains didodecyl methyl (4-aminobenzyl) ammonium chloride; the following step (2) finally obtains didodecyl methyl (p-3-carboxyacrylamidobenzyl) ammonium chloride DC, a hydrophobic monomer with a benzene ring structure 12 MCABAC.

[0040] The preparation method of the above-mentioned 2-allylmethylaminoethanesulfonic acid sodium AMES-Na comprises the following process steps: adding 200 mL of anhydrous ethanol as a solvent to a 500 mL three-necked flask equipped with a thermometer, a reflux condenser with a Soxhlet extractor and a magnetic rotor, adding 85 g of sodium 2-chloroethylsulfonate at a temperature of 25° C., then slowly adding 38 g of N-methylallylamine under stirring, adding 0.19 g of methylhydroquinone as an inhibitor, and charging 42 g of potassium carbonate wrapped with filter paper into the Soxhlet extractor, raising the temperature to reflux, reacting at a constant temperature for 25 hours, and removing the solvent and excess N-methylallylamine by reduced pressure distillation using a rotary evaporator to obtain 2-allylmethylaminoethanesulfonic acid sodium AMES-Na.

[0041] The above hydrophobic monomer with benzene ring structure didodecylmethyl (p-3-carboxyacrylamide benzyl) ammonium chloride DC 12The preparation method of MCABAC comprises the following process steps: (1) adding 200 mL of anhydrous ethanol as a solvent to a 500 mL three-necked flask equipped with a thermometer, a reflux condenser and a magnetic rotor, adding 110 g of didodecylmethyl tertiary amine at a temperature of 25° C. and with magnetic stirring turned on, then slowly adding 37 g of p-aminobenzyl chloride under stirring, raising the temperature to reflux, reacting at constant temperature for 14 hours, removing the solvent by reduced pressure distillation using a rotary evaporator, and then recrystallizing using acetone to obtain didodecylmethyl (4-aminobenzyl) ammonium chloride; (2) adding 100 g of didodecylmethyl tertiary amine to a 500 mL three-necked flask equipped with a thermometer, a reflux condenser and a magnetic rotor, and then 80 mL of anhydrous ethanol is used as a solvent, 85 g of didodecylmethyl (4-aminobenzyl) ammonium chloride is added under the condition of 25° C. and magnetic stirring is turned on, then 19 g of maleic anhydride is slowly added under stirring, the temperature is raised to 65° C., and the reaction is carried out at a constant temperature for 8 hours to obtain a reaction solution, a pH regulator is added to the reaction solution to adjust the pH value of the reaction solution to neutral, the pH regulator is a sodium hydroxide aqueous solution with a mass percentage concentration of 20%, and then the solvent is removed by reduced pressure distillation using a rotary evaporator, and then separated and purified using anhydrous ethanol to obtain a hydrophobic monomer didodecylmethyl (p-3-carboxyacrylamide benzyl) ammonium chloride DC with a benzene ring structure. 12 MCABAC.

[0042] The preparation method of the double-tailed hydrophobic associating polymer oil-displacing agent with a benzene ring structure comprises the following process steps: firstly, 1200 mole parts of distilled water are added into a reactor, and 81.22 mole parts of acrylamide AM, 18.51 mole parts of 2-allylmethylaminoethanesulfonic acid sodium AMES-Na, emulsifier hexadecyltrimethylammonium bromide (the amount of emulsifier hexadecyltrimethylammonium bromide added is 0.08% of the total mass of the reaction solution), hydrophobic monomer didodecylmethyl (p-3-carboxyacrylamide benzyl) ammonium chloride DC with a benzene ring structure are added in sequence under stirring. 12 0.27 mole of MCABAC, and then distilled water was added to control the total mass percentage concentration of the reaction monomers to 25%, and after stirring evenly, N2 was passed through to deoxygenate for 30 minutes; then 0.2% of the initiator of the total mass of the reaction monomers was added, and N2 was continued to be passed through, and the reaction was carried out under nitrogen protection at 55°C for 6 hours. The above reaction monomers are the three monomers mentioned above; after the reaction, the obtained gel product was washed with anhydrous ethanol, and the product was crushed and dried to obtain AM / AMES / DC 12 MCABAC terpolymer, the terpolymer is a hydrophobic associating polymer oil-displacing agent with a benzene ring double tail (that is, the polymer oil-displacing agent of the present invention).

[0043] The above-mentioned initiator is a composite initiator, including an oxidation-reduction system initiator and a water-soluble azo initiator. In the above-mentioned oxidation-reduction system initiator, the oxidant is ammonium persulfate, the reductant is sodium bisulfite, and the molar ratio of the oxidant to the reductant is 1:1.2. The above-mentioned water-soluble azo initiator is a combination of azobisisobutylamidine hydrochloride (V-50) and azobis(N-2-carboxyethyl-2-methylpropionamidine) hydrate (VA-057), and the mass ratio of V-50 to VA-057 is 1.5:1. In the composite initiator, the mass ratio of the oxidation-reduction system initiator to the water-soluble azo initiator is 1:1.7.

[0044] The following is the experimental (test) part of the present invention:

[0045] Experiment 1: AM / AMES / DC 10 Structural characterization of the MCABAC terpolymer oil-displacing agent (ie, the polymer oil-displacing agent of the present invention).

[0046] The structure of the polymer PAAD (i.e., the polymer oil displacement agent of the present invention) prepared in Example 1 was analyzed as follows: The FTIR spectrum of the polymer is as follows: Figure 1 Shown: 3338cm -1 -NH (antisymmetric) stretching vibration absorption peak; 3197cm -1 is the stretching vibration absorption peak of -NH (symmetric); 2926cm -1 and 2851cm -1 They are the asymmetric and symmetric stretching vibration absorption peaks of methylene respectively; 1650cm -1 It is -C=O stretching vibration absorption peak; 1609cm -1 Benzene ring skeleton vibration absorption peak; 1450cm -1 The absorption peaks are the in-plane bending vibration absorption peaks of methylene and the vibration absorption peaks of benzene skeleton; 1417 cm -1 is the absorption peak of amide CN stretching vibration; 1349cm -1 The CN stretching vibration absorption peaks of amine and quaternary ammonium salt are at 1318 cm -1 is the CO stretching vibration absorption peak of carboxylic acid; 1185cm -1 and 1039cm -1 -SO3 characteristic absorption peak; 854cm -1 It is the absorption peak of the out-of-plane bending vibration of the benzene ring. The infrared spectrum confirms that the product contains structures such as -CONH2, -SO3, -CH2-, -CH3, -COO-, -C6H4-, tertiary amine, and quaternary ammonium salt. From the infrared spectrum data, it can be proved that the target product is AM / AMES / DC 10 MCABAC terpolymer.

[0047] Experiment 2: AM / AMES / DC 10 Viscosity test experiment of MCABAC ternary copolymer oil displacing agent (i.e., polymer oil displacing agent of the present invention).

[0048] At room temperature (25±1°C), the apparent viscosities of the polymer PAAD (i.e., the polymer oil displacement agent of the present invention) and HPAM solution (prepared with distilled water) prepared in Example 1 with different concentrations were measured using a NDJ-5S digital rotational viscometer to investigate the changes in the apparent viscosities of the two solutions with the polymer concentration. Figure 2 .Depend on Figure 2 It can be seen that at 1000 mg / L, the two polymers PAAD and HPAM can reach 51.3 mPa·s and 27.3 mPa·s respectively, at 2000 mg / L, they can reach 257.6 mPa·s and 117.2 mPa·s respectively, and at 4000 mg / L, they can reach 1357 mPa·s and 257.8 mPa·s respectively. The results show that compared with HPAM, when the concentration exceeds 1000 mg / L, the synthesized polymer (i.e., the polymer oil-displacing agent of the present invention, the same below) exhibits better viscosity-increasing ability.

[0049] Experiment 3: AM / AMES / DC 10 Experimental test on the temperature resistance of the MCABAC ternary copolymer oil-displacing agent (i.e., the polymer oil-displacing agent of the present invention).

[0050] The polymer PAAD (i.e., the polymer oil-displacing agent of the present invention) and HPAM prepared in Example 1 were prepared into 2000 mg / L aqueous solutions with distilled water, and the apparent viscosity of the two polymer solutions was measured at 25°C to 90°C as a function of temperature. Figure 3 .Depend on Figure 3 It can be seen that the apparent viscosity of the two polymer solutions gradually decreases with the increase of temperature, and PAAD shows better temperature resistance. When the temperature reaches 90℃, the apparent viscosity of PAAD and HPAM solutions are 135.4mPa·s and 37.5mPa·s respectively. Compared with the viscosity at 25℃, the viscosity retention rates of the two polymers are 52.56% and 32.00% respectively; the results show that compared with HPAM, the synthesized polymer shows better temperature resistance.

[0051] Experiment 4: AM / AMES / DC 10 Experimental test on salt resistance of MCABAC ternary copolymer oil-displacing agent (i.e., polymer oil-displacing agent of the present invention).

[0052] PAAD (i.e., the polymer oil-displacing agent of the present invention) and HPAM prepared in Example 1 were prepared into 2000 mg / L aqueous solutions using mixed brine of different concentrations (the ratio of various salts in the mixed brine was NaCl:KCl:CaCl2:MgCl2=7:2:0.6:0.4, mass ratio). The apparent viscosities of the two polymer solutions were measured at 25°C. Figure 4 .Depend on Figure 4 It can be seen that when the mineralization of the brine increases, the apparent viscosity of the two polymers increases first and then decreases. PAAD shows better salt resistance, showing salt thickening phenomenon below the mineralization of 5000mg / L, while HPAM shows salt thickening phenomenon below the mineralization of 3000mg / L. When the content of brine increases to 50000mg / L, the apparent viscosity of PAAD and HPAM solutions are 106.7mPa·s and 14.5mPa·s, respectively, and their viscosity retention rates are 41.42% and 12.37%, respectively; the results show that compared with HPAM, the synthesized polymer shows better salt resistance.

[0053] Experiment 5: AM / AMES / DC 10 Shear resistance test experiment of MCABAC ternary copolymer oil-displacing agent (ie, polymer oil-displacing agent of the present invention).

[0054] The polymer PAAD (i.e., the polymer oil displacement agent of the present invention) prepared in Example 1 was prepared into a target solution of 2000 mg / L using distilled water and 10000 mg / L composite brine, and the HPAM was prepared into a target solution of 2000 mg / L using distilled water. The polymer solutions were sheared at different speeds. The shear resistance of the two polymer solutions was investigated. Figure 5 .Depend on Figure 5 It can be seen that the apparent viscosity of the two polymer solutions decreases with the increase of shear rate. When the shear speed is 3500r / min, the apparent viscosity of the polymer PAAD in distilled water and salt water is 205.1mPa·s and 114.7mPa·s, respectively, and the apparent viscosity of HPAM is 73.1mPa·s; the viscosity retention rate of PAAD in two water qualities is 79.62% and 50.57%, respectively, and the viscosity retention rate of HPAM is 62.37%; when the speed reaches 17000r / min, the apparent viscosity of the polymer PAAD in distilled water and salt water is 99.2mPa·s and 52.1mPa·s, respectively, and the apparent viscosity of HPAM is 13.2mPa·s; the viscosity retention rate of PAAD in two water qualities is 38.51% and 22.97%, respectively, and the viscosity retention rate of HPAM is 11.26%. The results show that compared with HPAM, the synthesized polymer exhibits better shear resistance.

[0055] Experiment 6: AM / AMES / DC10 Indoor core flooding experiment of MCABAC terpolymer oil-displacing agent (i.e., polymer oil-displacing agent of the present invention).

[0056] The polymer PAAD prepared in Example 1 (i.e., the polymer oil-displacing agent of the present invention) was prepared into a 2000 mg / L aqueous solution using a mixed brine with a salinity of 30000 mg / L (the ratio of various salts in the brine was NaCl: KCl: CaCl2: MgCl2 = 7:2:0.6:0.4, mass ratio), a simulated reservoir temperature of 70°C, a simulated oil viscosity of 80.7 mPa·s, and a three-layer heterogeneous core of 4.5×4.5×30.0 cm. The average water permeability was about 1273×10 -3 μm 2 . The core saturated with simulated oil was displaced with brine at an injection rate of 1 mL / min. When the instantaneous water content exceeded 70%, polymer flooding was performed with an injection volume of 0.3 PV, followed by subsequent water flooding until the three instantaneous water content reached 95%. The final recovery was calculated. The same method was used for water flooding until the three instantaneous water content reached 95%. The experimental results show that the final recovery rate of water flooding is 30.52%, and the final recovery rate of polymer flooding is 47.55%. Through indoor oil recovery experiments, it was calculated that the polymer can increase the recovery rate by 17.03%. The polymer has a good oil recovery effect under high temperature and high mineralization.

[0057] In summary, the polymer oil-displacing agent prepared by the above embodiments of the present invention has good viscosity, temperature resistance and shear resistance; it shows good salt resistance in mixed brine with a salinity of ≥30000 mg / L; the indoor oil displacement experiment shows a good oil displacement effect, which can increase the crude oil recovery rate by more than 10%. The present invention provides a (water-soluble) double-tailed hydrophobic associating polymer oil-displacing agent with a benzene ring structure, which has good performance, good viscosity-increasing ability at high temperature and high salinity, and good shear resistance, achieves a high recovery rate, and can meet the technical requirements of the polymer oil-displacing agent with a wide range of use in the market, thereby ensuring the smooth progress of oil exploitation in high-temperature and high-salinity oil fields, and solving the problems that the existing hydrophobic associating polymer has poor temperature and salt resistance in brine with high salinity (mineralization ≥30000 mg / L), is easily hydrolyzed underground, and has a low crude oil recovery rate.

Claims

1. A double-tailed hydrophobic associating polymer oil-displacing agent with a benzene ring structure, characterized in that It is composed of acrylamide AM, 2-allylmethylaminoethylsulfonic acid sodium AMES-Na and a hydrophobic monomer with a benzene ring structure and a double-tailed long-chain alkylmethyl (p-3-carboxyacrylamide benzyl) ammonium chloride DC n MCABAC is copolymerized by three monomers, and the structural formula of the polymer oil displacement agent is as follows: In the above structural formula, x, y, and z are the molar percentage ranges of the structural units: x=69.5% to 84.9%, y=15% to 30%, z=0.1% to 0.5%, x+y+z=100%, wherein n=8, 10, 12, or 14.

2. The double-tailed hydrophobic associating polymer oil-displacing agent with a benzene ring structure according to claim 1, characterized in that The molar fractions of each monomer are as follows: 69.5-84.9 parts of acrylamide AM, 15-30 parts of 2-allylmethylaminoethylsulfonate AMES-Na, and a hydrophobic monomer with a benzene ring structure, a double-tailed long-chain alkylmethyl (p-3-carboxyacrylamide benzyl) ammonium chloride DC n MCABAC 0.1~0.5 parts.

3. The betaine type hydrophobically associating polymer oil-displacing agent having a cyclic structure according to claim 1 or 2, characterized in that The preparation method of 2-allylmethylaminoethanesulfonic acid sodium AMES-Na comprises the following process steps: adding an appropriate amount of anhydrous ethanol as a solvent to a three-necked flask equipped with a thermometer, a reflux condenser with a Soxhlet extractor and a magnetic rotor, adding 65-95 g of sodium 2-chloroethylsulfonate at room temperature, then slowly adding 30-43 g of N-methylallylamine under stirring, adding 0.15-0.21 g of methylhydroquinone as an inhibitor, and charging 32-47 g of an acid binding agent wrapped with filter paper into the Soxhlet extractor, raising the temperature to reflux, reacting at a constant temperature for 20-25 hours, and removing the solvent and excess N-methylallylamine by reduced pressure distillation using a rotary evaporator to obtain 2-allylmethylaminoethanesulfonic acid sodium AMES-Na.

4. The double-tailed hydrophobic associating polymer oil-displacing agent with a benzene ring structure according to claim 1 or 2, characterized in that The above hydrophobic monomer with benzene ring structure has double tail long chain alkyl methyl (p-3-carboxy acrylamide benzyl) ammonium chloride DC n The preparation method of MCABAC comprises the following process steps: (1) adding an appropriate amount of anhydrous ethanol as a solvent to a three-necked flask equipped with a thermometer, a reflux condenser and a magnetic rotor, adding 90 to 130 g of a double-tailed long-chain alkylmethyl tertiary amine at room temperature and with magnetic stirring on, then slowly adding 30 to 45 g of p-aminobenzyl chloride under stirring, raising the temperature to reflux, reacting at constant temperature for 10 to 15 hours, removing the solvent by reduced pressure distillation using a rotary evaporator, and then recrystallizing using acetone to obtain double-tailed long-chain alkylmethyl (4-aminobenzyl) ammonium chloride; (2) adding 10 to 20 g of methyl 4-aminobenzyl ammonium chloride to a three-necked flask equipped with a thermometer, a reflux condenser and a magnetic rotor. In a bottle, add an appropriate amount of anhydrous ethanol as a solvent, add 70-110g of double-tailed long-chain alkylmethyl (4-aminobenzyl) ammonium chloride at room temperature and with magnetic stirring turned on, then slowly add 15-25g of maleic anhydride under stirring, raise the temperature to 60-70°C, react at constant temperature for 6-8 hours, and obtain a reaction solution. Add a pH adjuster to the reaction solution to adjust the pH value of the reaction solution to neutral, then use a rotary evaporator to remove the solvent under reduced pressure, and then use anhydrous ethanol to separate and purify, so as to obtain a hydrophobic monomer double-tailed long-chain alkylmethyl (p-3-carboxyacrylamide benzyl) ammonium chloride DC with a benzene ring structure. n MCABAC.

5. The double-tailed hydrophobic associating polymer oil-displacing agent with a benzene ring structure according to claim 1, characterized in that The preparation method comprises the following process steps: firstly, 1000-1500 mole parts of distilled water are added into a reactor, and then 69.5-84.9 mole parts of acrylamide AM, 15-30 mole parts of 2-allylmethylaminoethylsulfonic acid sodium AMES-Na, an emulsifier, and a double-tailed long-chain alkyl methyl (p-3-carboxyacrylamide benzyl) ammonium chloride DC are added in sequence under stirring. n MCABAC 0.1-0.5 molar parts, and then distilled water is added to control the total mass percentage concentration of the reaction monomers to be between 15% and 30%, and stirred evenly, and N2 is passed for 30-35 minutes, and then an initiator is added, and N2 is continued to be passed, and the reaction is carried out under nitrogen protection at 30-60°C for 4-10 hours. The above reaction monomers are the three monomers mentioned above; after the reaction, the obtained gel product is washed with anhydrous ethanol, and the product is crushed and dried to obtain AM / AMES / DC n MCABAC terpolymer is a double-tailed hydrophobic associating polymer oil displacement agent with a benzene ring structure.

6. The double-tailed hydrophobic associating polymer oil-displacing agent with a benzene ring structure according to claim 5, characterized in that The above-mentioned initiator is a composite initiator, including an oxidation-reduction system initiator and a water-soluble azo initiator. In the oxidation-reduction system initiator, the oxidant is potassium persulfate or ammonium persulfate, the reductant is sodium bisulfite, and the molar ratio of the oxidant to the reductant is 1:1 to 1.5; the water-soluble azo initiator is one or a combination of azobisisobutylamidine hydrochloride V-50, azobisisobutylimidazoline hydrochloride VA-044, and azobis(N-2-carboxyethyl-2-methylpropionamidine) hydrate VA-057, and the ratio of the combination is arbitrary; in the composite initiator, the mass ratio of the oxidation-reduction system initiator to the water-soluble azo initiator is 1:1 to 2.

7. The double-tailed hydrophobic associating polymer oil-displacing agent with a benzene ring structure according to claim 3, characterized in that The above acid binding agent is potassium carbonate or sodium carbonate.

8. The double-tailed hydrophobic associating polymer oil-displacing agent with a benzene ring structure according to claim 4, characterized in that The pH value adjusting agent is a sodium hydroxide aqueous solution with a mass percentage concentration of 20%; The above hydrophobic monomer with benzene ring structure has double tail long chain alkyl methyl (p-3-carboxy acrylamide benzyl) ammonium chloride DC n In MCABAC, the long-chain alkyl group is selected from decyl, and the double-tailed long-chain alkyl methyl tertiary amine is didecyl methyl tertiary amine; step (2) finally obtains didecyl methyl (p-3-carboxyacrylamide benzyl) ammonium chloride DC with a benzene ring structure. 10 MCABAC; or, The above hydrophobic monomer with benzene ring structure has double tail long chain alkyl methyl (p-3-carboxy acrylamide benzyl) ammonium chloride DC n In MCABAC, the long-chain alkyl group is dodecyl, and the double-tail long-chain alkyl methyl tertiary amine is didodecyl methyl tertiary amine; step (2) finally obtains didodecyl methyl (p-3-carboxyacrylamide benzyl) ammonium chloride DC with a benzene ring structure. 12 MCABAC.

9. The double-tailed hydrophobic associating polymer oil-displacing agent with a benzene ring structure according to claim 5, characterized in that The emulsifier is hexadecyltrimethylammonium bromide, and the amount of hexadecyltrimethylammonium bromide added is 0.06% to 0.1% of the total mass of the reaction solution; the amount of the initiator added is 0.05% to 0.2% of the total mass of the reaction monomers, and the total mass of the reaction monomers is the total mass of the three monomers mentioned above.

10. A method for preparing the double-tailed hydrophobic associating polymer oil-displacing agent with a benzene ring structure as claimed in claim 1, characterized in that The method comprises the following process steps: firstly, 1000-1500 mole parts of distilled water are added into a reactor, and then 69.5-84.9 mole parts of acrylamide AM, 15-30 mole parts of 2-allylmethylaminoethylsulfonic acid sodium AMES-Na, an emulsifier, and a double-tailed long-chain alkyl methyl (p-3-carboxyacrylamide benzyl) ammonium chloride DC are added in sequence under stirring. n MCABAC 0.1-0.5 molar parts, and then distilled water is added to control the total mass percentage concentration of the reaction monomers to be between 15% and 30%, and stirred evenly, and N2 is passed for 30-35 minutes, and then an initiator is added, and N2 is continued to be passed, and the reaction is carried out under nitrogen protection at 30-60°C for 4-10 hours. The above reaction monomers are the three monomers mentioned above; after the reaction, the obtained gel product is washed with anhydrous ethanol, and the product is crushed and dried to obtain AM / AMES / DC n MCABAC terpolymer is a double-tailed hydrophobic associating polymer oil displacement agent with a benzene ring structure.

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