CN111978945A

CN111978945A - Viscosity reduction auxiliary agent for thickened oil, preparation method and application thereof

Info

Publication number: CN111978945A
Application number: CN202010905405.5A
Authority: CN
Inventors: 张欢乐; 王耀国
Original assignee: Ningbo Fengcheng Advanced Energy Materials Research Institute Co Ltd
Current assignee: Ningbo Fengcheng Advanced Energy Materials Research Institute Co Ltd
Priority date: 2020-09-01
Filing date: 2020-09-01
Publication date: 2020-11-24
Anticipated expiration: 2040-09-01
Also published as: CN111978945B

Abstract

The application discloses a thick oil viscosity reduction auxiliary agent, which comprises an acrylamide-styrene copolymer and a lamellar material; the acrylamide-styrene copolymer is obtained by in-situ polymerization of an acrylamide monomer and a styrene monomer on the sheet material; the sheet material comprises at least one of graphene oxide, montmorillonite and molybdenum disulfide. The viscosity reduction auxiliary agent for the thick oil can effectively improve the viscosity reduction efficiency of the thick oil viscosity reducer.

Description

Viscosity reduction auxiliary agent for thickened oil, preparation method and application thereof

Technical Field

The application relates to a viscosity reducing auxiliary agent for thick oil, a preparation method thereof and a viscosity reducing agent containing the viscosity reducing auxiliary agent for thick oil, belonging to the field of viscosity reduction of thick oil.

Background

With the rapid development of science and technology, the oil consumption in China is obviously increased, the oil resources are more and more tense, and the exploitation of thick oil is imperative in order to relieve the problem of lack of oil resources. It is estimated that the heavy oil resource is about 250 hundred million tons in China, and accounts for 28 percent of the total geological reserves of petroleum. However, the recovery of thick oil is not a simple matter, and China faces a great challenge in the aspect of thick oil development.

The viscosity reduction method commonly used in China and outside in the process of thick oil exploitation comprises a heating method, a thin oil mixing method, thick oil modification viscosity reduction and a chemical agent viscosity reduction method. The emulsifying viscosity reducer is added during the steam flooding of the thickened oil, is a relatively new thickened oil exploitation technology, the main component of the emulsifying viscosity reducer is a surfactant, and the thickened oil in the stratum is changed from a water-in-oil emulsifying state into an emulsifying state taking water as an external phase by reducing the interfacial tension of oil and water, so that the viscosity of the thickened oil is greatly reduced, and the recovery ratio is obviously improved.

The viscosity reducer for the oil-soluble thick oil in the existing viscosity reducer has a good viscosity reducing effect, but has higher operation cost, is less applied in an oil field, is more favored by the oil field, but has the problems of high content of active ingredients, higher cost, unsatisfactory viscosity reducing effect and the like, so that the application of the viscosity reducer in the oil field is limited, and therefore, a novel efficient viscosity reducer for the thick oil is urgently needed to be developed to solve the problems encountered in the thick oil exploitation.

Disclosure of Invention

According to one aspect of the application, the viscosity reduction auxiliary agent for the thick oil is provided, and can effectively improve the viscosity reduction efficiency of the thick oil viscosity reducer.

The thickened oil viscosity reduction auxiliary agent comprises acrylamide-styrene copolymer and a lamellar material;

the acrylamide-styrene copolymer is obtained by in-situ polymerization of an acrylamide monomer and a styrene monomer on the sheet material;

the sheet material comprises at least one of graphene oxide, montmorillonite and molybdenum disulfide.

According to the thick oil viscosity reduction auxiliary agent, the introduction of the amide group is beneficial to the formation of hydrogen bonds between graphene oxide and asphaltene colloid and other polar substances, and secondly, the network space structure of polyacrylamide is easy to carry active substance molecules. The active substances enter between the flaky molecules of colloid and asphaltene by virtue of strong hydrogen bond forming capability and permeation and dispersion effects, so that the active substances can effectively and intelligently react with the original active substances, and the viscosity of the crude oil is reduced; the introduction of styrene is beneficial to the reduction of the polarity of a polymer, so that a polyacrylamide molecular chain is more stretched and is convenient for carrying active substances, and secondly, asphalt and colloid in thickened oil contain a large number of functional groups with benzene ring structures, and the introduction of benzene rings can more intelligently find the functional groups, so that the viscosity reduction effect is reduced and improved. The unique lamellar structure of the graphene oxide can insert carried active molecules into the thick oil block more easily, so that the effects of dispersion and emulsification are exerted, the viscosity of the thick oil is reduced, the graphene oxide has certain rigidity and strength, if the active molecules have the effect of dispersing the thick oil, asphalt colloid in the thick oil block can not be polymerized again after dispersion to cause the viscosity to be improved again, and if the active molecules have the effect of emulsifying and viscosity reduction, the rigidity of the graphene oxide can also make the oil-in-water emulsion more stable, and the stability of the emulsion is improved.

Optionally, the particle size of the thickened oil viscosity reduction auxiliary agent measured by dynamic light scattering is 10-500 nm at a temperature of 20 ℃ and a concentration of 0.005%.

Optionally, the particle size of the heavy oil viscosity reduction auxiliary agent measured by dynamic light scattering has an upper limit independently selected from 500nm, 450nm, 400nm, 350nm, 300nm, 250nm, 200nm, 150nm, 100nm and 50nm, and a lower limit independently selected from 10nm, 450nm, 400nm, 350nm, 300nm, 250nm, 200nm, 150nm, 100nm and 50 nm.

Optionally, the mass ratio of the acrylamide monomer to the styrene monomer to the sheet material is 0.1-10: 0.001 to 1.

Preferably, the mass ratio of the acrylamide monomer to the styrene monomer to the sheet material is 0.5-10: 0.1-5: 0.005-0.1.

Further preferably, the mass ratio of the acrylamide monomer to the styrene monomer to the sheet material is 1-5: 0.5-5: 0.005-0.05.

According to another aspect of the application, a preparation method of the thick oil viscosity reducer is provided, and the method is simple in process, easy to control and capable of realizing large-scale preparation.

The method comprises the following steps:

adding an initiator into a solution containing a lamellar material, an acrylamide monomer and a styrene monomer, and carrying out polymerization reaction to obtain the thick oil viscosity reducer.

Optionally, the initiator is a water soluble initiator.

Optionally, the water-soluble initiator is selected from at least one of potassium persulfate, ammonium persulfate, azobisisobutyramidine hydrochloride, and azobisisobutyrimidazoline hydrochloride.

Optionally, the solution containing the sheet material, the acrylamide monomer and the styrene monomer further comprises a solvent;

the solvent is at least one selected from water, ethanol, polyethylene glycol, glycerol and toluene.

Optionally, the ratio of the mass of the initiator to the total mass of the propionamide monomer and the styrene monomer is 0.01-1: 0.2-20.

Preferably, the ratio of the mass of the initiator to the total mass of the propionamide monomer and the styrene monomer is 0.05-1: 1-20.

Further, the ratio of the mass of the initiator to the total mass of the propionamide monomer and the styrene monomer is 0.05-0.5: 1-5.

Alternatively, the method for preparing the solution containing the sheet material, the acrylamide monomer and the styrene monomer comprises the following steps:

and mixing the solution containing the sheet material with a solution containing an acrylamide monomer and a styrene monomer to obtain the solution containing the sheet material, the acrylamide monomer and the styrene monomer.

Optionally, the solution containing the sheet material further comprises a solvent;

the solvent is selected from water.

Optionally, the concentration of the sheet material in the solution containing the sheet material is 100-5000 mg/L.

Alternatively, the upper limit of the concentration of the sheet material in the solution containing the sheet material is independently selected from 5000mg/L, 4500mg/L, 4000mg/L, 3500mg/L, 3000mg/L, 2500mg/L, 2000mg/L, 1500mg/L, 1000mg/L, 500mg/L, 300mg/L, and the lower limit is independently selected from 4500mg/L, 4000mg/L, 3500mg/L, 3000mg/L, 2500mg/L, 2000mg/L, 1500mg/L, 1000mg/L, 500mg/L, 300mg/L, 100 mg/L.

Optionally, the solution containing the propionamide monomer and the styrene monomer further comprises a solvent;

the solvent is at least one selected from ethanol, methanol, glycerol, toluene and hexane.

Optionally, the mass ratio of the acrylamide monomer to the styrene monomer to the solvent is 0.1-10: 5 to 100.

Preferably, the mass ratio of the acrylamide monomer to the styrene monomer to the solvent is 0.5-10: 0.1-5: 10 to 50.

Further preferably, the mass ratio of the acrylamide monomer to the styrene monomer to the solvent is 1-5: 0.5-5: 20 to 50.

Optionally, the mass ratio of the solution containing the sheet material to the solution containing the acrylamide monomer and the styrene monomer is 10: 1-50: 1.

alternatively, the upper limit of the mass ratio of the solution containing the sheet material to the solution containing the acrylamide monomer and the styrene monomer is independently selected from 50: 1. 45, and (2) 45: 1. 40: 1. 35: 1. 30: 1. 25: 1. 20: 1. 15: 1, the lower limit is independently selected from 10: 1. 45, and (2) 45: 1. 40: 1. 35: 1. 30: 1. 25: 1. 20: 1. 15: 1.

optionally, the initiator is added in a manner that: and (3) carrying out inactive atmosphere replacement on the solution containing the lamellar material, the acrylamide monomer and the styrene monomer, stirring, heating to 30-60 ℃, and adding the initiator.

Alternatively, the conditions of the polymerization reaction are: the reaction temperature is 70-95 ℃, and the reaction time is 1-6 hours.

According to another aspect of the application, the thick oil viscosity reducer is obtained by compounding the thick oil viscosity reducer auxiliary agent and a surfactant, can be used for viscosity reduction of ultra-thick oil, and can effectively improve the viscosity reduction efficiency of the viscosity reducer as the viscosity reducer auxiliary agent. The following problems are solved: 1) in the prior art, the PAM/GO composite material is synthesized in a fixed proportion and is only used for oil displacement, but the effect is not ideal, and the material is not related to the field of viscosity reduction of thick oil; 2) in the prior art, the viscosity reduction performance of the terpolymer esterified substance-comb polymer is improved by adjusting the proportion of each monomer component, but the viscosity reduction effect of the polymer directly used for reducing the viscosity of the thick oil is not ideal, and is only 70 percent at most; 3) the two materials are directly used for viscosity reduction of thick oil, have large molecular size, are difficult to enter the inside of thick oil molecules, and play a role in thick oil with high viscosity.

The thick oil viscosity reducer comprises a surfactant and a thick oil viscosity reduction auxiliary agent;

the viscosity reducer auxiliary agent is at least one selected from the viscosity reducer auxiliary agent and the viscosity reducer auxiliary agent prepared by the method.

Optionally, the surfactant is selected from at least one of an anionic surfactant, a nonionic surfactant, and a zwitterionic surfactant;

the anionic surfactant is selected from at least one of sulfonate anionic surfactant and sulfate anionic surfactant;

the nonionic surfactant is selected from at least one of polyoxyethylene type nonionic surfactants and polyhydric alcohol type nonionic surfactants;

the zwitterionic surfactant is selected from at least one of betaine surfactant and amino acid surfactant.

Optionally, the mass ratio of the surfactant to the thick oil viscosity reduction auxiliary agent is 10-100: 0.1 to 10.

Preferably, the mass ratio of the surfactant to the thick oil viscosity reduction auxiliary agent is 10-50: 0.1 to 5.

Further preferably, the mass ratio of the surfactant to the thick oil viscosity reduction auxiliary agent is 20-50: 0.1 to 0.5.

Optionally, the thick oil viscosity reducer is prepared into an aqueous solution for use;

in the aqueous solution, the concentration of the thickened oil viscosity-reducing auxiliary agent in the aqueous solution is 0.001-0.1 wt%.

Preferably, in the aqueous solution, the concentration of the thick oil viscosity reduction auxiliary agent in the aqueous solution is 0.001-0.01 wt%.

Further preferably, in the aqueous solution, the concentration of the thick oil viscosity reduction auxiliary agent in the aqueous solution is 0.002-0.005 wt%.

Optionally, the method for using the thick oil viscosity reducer comprises the following steps:

and mixing the aqueous solution with the thick oil to reduce the viscosity of the thick oil.

Alternatively, the viscosity of the thick oil at 50 ℃ is not less than 1320mPa · s.

The beneficial effects that this application can produce include:

1) the thick oil viscosity reduction auxiliary agent provided by the application has a nanoscale size, and is compounded with other active substances such as an emulsifier to obtain a novel thick oil viscosity reduction agent.

2) The thick oil viscosity reducer provided by the application can be used for viscosity reduction of super-thick oil, and can effectively improve the viscosity reduction efficiency of the viscosity reducer as a viscosity reducer auxiliary agent

3) The preparation method of the viscosity-reducing auxiliary agent for thickened oil is simple in process, easy to control and capable of realizing large-scale preparation.

Drawings

FIG. 1 is a graph of the infrared spectrum of sample 1 prepared in example 1;

fig. 2 is a dynamic light scattering particle size distribution diagram of sample 1 prepared in example 1.

Detailed Description

The present application will be described in detail with reference to examples, but the present application is not limited to these examples.

The raw materials in the examples of the present application were all purchased commercially, unless otherwise specified.

Graphene oxide was purchased from hexite materials science and technology ltd, changzhou.

The analysis method in the examples of the present application is as follows:

particle size analysis was performed using a malvern ZSE nano-particle size potentiometer.

Viscosity analysis was performed using a boehler fly DV2TLVTJ0 rotational viscometer.

Infrared analysis was performed using a Nicolet is50 model Infrared spectrometer.

EXAMPLE 1 preparation of viscosity-reducing adjuvant for thickened oils

1) Diluting a graphene oxide sheet material to 1000mg/L by using pure water according to the solid content provided by a manufacturer, and uniformly stirring;

2) carrying out ultrasonic shearing on the graphene oxide laminar material diluent, wherein the ultrasonic frequency is 40kHZ, and the ultrasonic time is 2h, so that the size of the graphene oxide laminar material reaches the nano level (small size can easily enter between laminar molecules of colloid and asphaltene, and the laminar structure has certain strength and can be easily embedded into a space network structure of thick oil), thereby obtaining a laminar nano material solution;

3) 1g of styrene and 2g of acrylamide were added to 20g of ethanol and stirred rapidly until completely dissolved (mechanical stirring speed: 300 revolutions per minute, stirring time: 10 minutes) (where the amount of AM is much less than in the prior art), a monomer solution is obtained;

4) adding the monomer solution obtained in the step 3) into the lamella nano material solution, and uniformly stirring to obtain a mixed solution; wherein the lamellar nanomaterial solution: the mass ratio of the monomer solution is 20: 1;

5) introducing nitrogen to replace air in the flask, wherein the nitrogen introducing speed is as follows: 3m/s, time: 30 minutes;

6) keeping the stirring speed at 500 r/min, starting heating, adding 0.1g of potassium persulfate when the temperature of the system is raised to 30 ℃, continuously heating to 70 ℃, and reacting for 5 hours;

7) and 5) cooling the reaction liquid obtained in the step 5) to room temperature to obtain a novel thick oil viscosity reducer auxiliary agent based on graphene oxide, and recording as a sample 1.

EXAMPLE 2 preparation of viscosity-reducing adjuvant for thickened oils

1) Diluting the graphene oxide sheet material to 500mg/L by using pure water according to the solid content provided by a manufacturer, and uniformly stirring;

2) carrying out ultrasonic shearing on the graphene oxide laminar material diluent, wherein the ultrasonic frequency is 40kHZ, and the ultrasonic time is 2h, so that the size of the laminar material reaches the nano level (the small size can more easily enter between laminar molecules of colloid and asphaltene, and the laminar structure has certain strength and can be easily embedded into a space net structure of thick oil), thereby obtaining a laminar nano material solution;

3) 0.5g of styrene and 2g of acrylamide were added to 50g of ethanol and stirred rapidly until completely dissolved (mechanical stirring speed: 800 revolutions per minute, stirring time: 30 minutes) (where the amount of AM is much less than in the prior art);

4) adding the monomer solution obtained in the step 3) into the lamella nano material solution, and uniformly stirring to obtain a mixed solution; wherein the lamellar nanomaterial solution: the mass ratio of the monomer solution is 30: 1;

5) introducing nitrogen to replace air in the flask, wherein the nitrogen introducing speed is as follows: 5m/s, time: 20 minutes;

6) keeping the stirring speed at 800 r/min, starting heating, adding 0.3g of potassium persulfate when the temperature of the system is raised to 60 ℃, continuously heating to 90 ℃, and reacting for 3 h;

7) and 5) cooling the reaction liquid obtained in the step 5) to room temperature to obtain a novel thick oil viscosity reducer auxiliary agent based on graphene oxide, and recording as a sample 2.

EXAMPLE 3 preparation of viscosity-reducing adjuvant for thickened oils

1) Diluting the montmorillonite sheet material to 1000mg/L with pure water according to the solid content provided by a manufacturer, and uniformly stirring;

2) carrying out ultrasonic shearing on the montmorillonite sheet material diluent, wherein the ultrasonic frequency is 40kHZ, and the ultrasonic time is 0.5h, so that the size of the montmorillonite sheet material reaches the nano level (the small size is easier to enter between colloid and asphaltene sheet molecules, and the sheet structure has certain strength and can be easily embedded into a space net structure of thick oil), thereby obtaining a sheet nano material solution;

3) 2g of styrene and 1.5g of acrylamide were added to 30g of ethanol, and the mixture was rapidly stirred until completely dissolved (mechanical stirring speed: 500 rpm, stirring time: 30 minutes) (where the amount of AM is much less than in the prior art), a monomer solution is obtained;

4) adding the monomer solution obtained in the step 3) into the lamella nano material solution, and uniformly stirring to obtain a mixed solution; wherein the lamellar nanomaterial solution: the mass ratio of the monomer solution is 40: 1;

6) keeping the stirring speed at 500 r/min, starting heating, adding 0.05g of potassium persulfate when the temperature of the system is raised to 30 ℃, continuously heating to 70 ℃, and reacting for 3 hours;

7) and (3) cooling the reaction liquid obtained in the step 5) to room temperature to obtain a novel thick oil viscosity reducer auxiliary agent based on graphene oxide, and recording the auxiliary agent as a sample 3.

EXAMPLE 4 preparation of viscosity-reducing adjuvant for thickened oils

1) Diluting the molybdenum disulfide sheet material to 3000mg/L by pure water according to the solid content provided by a manufacturer, and uniformly stirring;

2) carrying out ultrasonic shearing on the diluted solution of the molybdenum disulfide sheet material, wherein the ultrasonic frequency is 40kHZ, and the ultrasonic time is 0.5h, so that the size of the molybdenum disulfide sheet material reaches the nano level (small size can more easily enter between sheet molecules of colloid and asphaltene, and then the sheet structure has certain strength and can also be easily embedded into a space network structure of thick oil), and obtaining a sheet nano material solution;

3) 1g of styrene and 2g of acrylamide were added to 20g of ethanol and stirred rapidly until completely dissolved (mechanical stirring speed: 500 rpm, stirring time: 30 minutes) (where the amount of AM is much less than in the prior art), a monomer solution is obtained;

6) keeping the stirring speed at 800 r/min, starting heating, adding 0.3g of potassium persulfate when the temperature of the system is raised to 30 ℃, continuously heating to 80 ℃, and reacting for 5 hours;

7) and (3) cooling the reaction liquid obtained in the step 5) to room temperature to obtain a novel thick oil viscosity reducer auxiliary agent based on graphene oxide, and recording as a sample 4.

Example 5 characterization of sample 1

The infrared test was performed on the samples prepared in examples 1 to 4, which are represented by sample 1, and the test results are shown in fig. 1. FIG. 1 is an IR spectrum of example 1, 3334cm in FIG. 1^-1、3185cm^-1-NH of the group corresponding to the peak₂Vibration, 2934cm^-1Peak to peak-CH of the corresponding group₂Vibration, 1644cm^-1Vibration of peak corresponding group-C ═ O, 1601cm^-1、1593cm^-1The peak corresponds to the vibration of the benzene ring skeleton of the group. The characteristic peaks in the ir spectra of the other samples are similar to those in fig. 1, differing only in the intensity of the peaks.

And respectively carrying out dynamic light scattering test on the solution of the samples 1-4 to test the particle size. The test method comprises the following steps: and preparing a solution with the concentration of 50mg/L and carrying out a dynamic light scattering test. Typical test results are shown in fig. 2, corresponding to example 1. FIG. 2 shows that the particle size distribution of sample 1 is around 300 nm.

EXAMPLE 6 preparation of viscosity reducer for thickened oils

1) Dissolving 0.2g of anionic surfactant fatty alcohol-polyoxyethylene ether sodium sulfate in 100mL of stratum simulation water; according to the standard Q/SH 10201519-2013 method, the composition of the stratum simulation water is as follows: 3.0% NaCl, 0.3% CaCl₂。

2) Adding 1mL of sample 1 (the heavy oil viscosity reducer auxiliary agent with the mass fraction of 0.2 wt%) into the solution obtained in the step 1), wherein the concentration of the auxiliary agent in the mixed solution is about 0.002 wt%, and obtaining a novel viscosity reducer which is marked as viscosity reducer 1.

EXAMPLE 7 preparation of viscosity reducer for thickened oils

1) Dissolving 0.2g of amphoteric surfactant cocoamidopropyl hydroxysultaine in 100mL of stratum simulation water; according to the standard Q/SH 10201519-2013 method, the composition of the stratum simulation water is as follows: 3.0% NaCl, 0.3% CaCl₂。

2) And (2) adding 2mL of a sample 2 (the heavy oil viscosity reducer auxiliary agent with the mass fraction of 0.1% by weight) into the solution obtained in the step 1), wherein the concentration of the auxiliary agent in the mixed solution is about 0.002% by weight, thus obtaining a novel viscosity reducer, which is marked as viscosity reducer 2.

EXAMPLE 8 preparation of viscosity reducer for thickened oils

1) Dissolving 90.3g of non-surfactant fatty alcohol-polyoxyethylene ether MOA in 100mL of formation simulation water; according to the standard Q/SH 10201519-2013 method, the composition of the stratum simulation water is as follows: 3.0% NaCl, 0.3% CaCl₂。

2) And (2) adding 0.5mL of a sample 3 (the heavy oil viscosity reducer auxiliary agent with the mass fraction of 0.5 wt%) into the solution obtained in the step 1), wherein the concentration of the auxiliary agent in the mixed solution is about 0.0025 wt%, so as to obtain a novel viscosity reducer, which is marked as viscosity reducer 3.

Comparative example 1

Dissolving 0.2g of anionic surfactant sodium alcohol ether sulfate in 100mL of formation simulation water, and marking as a viscosity reducer D1; according to the standard Q/SH 10201519-2013 method, the composition of the stratum simulation water is as follows: 3.0% NaCl, 0.3% CaCl₂。

Comparative example 2

Dissolving 0.2g of amphoteric surfactant cocoamidopropyl hydroxysultaine in 100mL of formation simulation water, and marking as a viscosity reducer D2; according to the standard Q/SH 10201519-2013 method, the composition of the stratum simulation water is as follows: 3.0% NaCl, 0.3% CaCl₂。

Comparative example 3

Dissolving 90.3g of non-surfactant fatty alcohol-polyoxyethylene ether MOA in 100mL of formation simulation water, and marking as a viscosity reducer D3; according to the standard Q/SH 10201519-2013 method, the composition of the stratum simulation water is as follows: 3.0% NaCl, 0.3% CaCl₂。

Example 9 Performance testing of thickened oil viscosity reducer

The following viscosity reduction methods for heavy oil were all performed according to the standard Q/SH 10201519-2013 method:

although the present application has been described with reference to a few embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the application as defined by the appended claims.

Claims

1. The viscosity-reducing auxiliary agent for the thick oil is characterized by comprising an acrylamide-styrene copolymer and a lamellar material;

2. The viscosity-reducing additive for thick oil according to claim 1, wherein the particle size of the viscosity-reducing additive for thick oil is 10-500 nm as measured by dynamic light scattering at a temperature of 20 ℃ and a concentration of 0.005%.

3. The viscosity-reducing auxiliary agent for thickened oil according to claim 1, wherein the mass ratio of the acrylamide monomer to the styrene monomer to the lamellar material is 0.1-10: 0.001 to 1.

4. The method for preparing the thick oil viscosity reduction aid according to any one of claims 1 to 3, which is characterized by comprising the following steps:

adding an initiator into a solution containing a lamellar material, an acrylamide monomer and a styrene monomer, and carrying out polymerization reaction to obtain the viscous oil viscosity reduction auxiliary agent.

5. The method of claim 4, wherein the initiator is a water-soluble initiator.

6. The method according to claim 5, wherein the water-soluble initiator is at least one selected from the group consisting of potassium persulfate, ammonium persulfate, azobisisobutyramidine hydrochloride, and azobisisobutyrimidazoline hydrochloride.

7. The method according to claim 4, wherein the solution containing the sheet material, the acrylamide monomer and the styrene monomer further comprises a solvent;

8. The preparation method according to claim 4, wherein the ratio of the mass of the initiator to the total mass of the propionamide monomer and the styrene monomer is 0.01-1: 0.2-20;

preferably, the preparation method of the solution containing the sheet material, the acrylamide monomer and the styrene monomer comprises the following steps:

mixing the solution containing the sheet material with a solution containing an acrylamide monomer and a styrene monomer to obtain the solution containing the sheet material, the acrylamide monomer and the styrene monomer;

preferably, the solution containing the sheet material further comprises a solvent;

the solvent is selected from water;

preferably, the concentration of the lamellar material in the solution containing lamellar material is 100-5000 mg/L;

preferably, the solution containing the propionamide monomer and the styrene monomer further comprises a solvent;

the solvent is at least one selected from ethanol, methanol, glycerol, toluene and hexane;

preferably, the mass ratio of the acrylamide monomer to the styrene monomer to the solvent is 0.1-10: 5-50;

preferably, the mass ratio of the solution containing the sheet material to the solution containing the acrylamide monomer and the styrene monomer is 10: 1-50: 1;

preferably, the initiator is added in the following manner: carrying out inactive atmosphere replacement on a solution containing a lamellar material, an acrylamide monomer and a styrene monomer, stirring, heating to 30-60 ℃, and adding the initiator;

preferably, the polymerization conditions are: the reaction temperature is 70-95 ℃, and the reaction time is 1-6 hours.

9. The viscosity reducer for the thick oil is characterized by comprising a surfactant and a viscosity reducing auxiliary agent for the thick oil;

the viscosity reducer auxiliary agent is at least one selected from the viscosity reducer auxiliary agent according to any one of claims 1 to 3 and the viscosity reducer auxiliary agent prepared by the method according to any one of claims 4 to 8.

10. The viscosity reducer for thick oil according to claim 9, wherein the surfactant is at least one selected from the group consisting of an anionic surfactant, a nonionic surfactant, and a zwitterionic surfactant;

the zwitterionic surfactant is selected from at least one of betaine type surfactant and amino acid type surfactant;

preferably, the mass ratio of the surfactant to the thick oil viscosity reduction auxiliary agent is 10-100: 0.1 to 10;

preferably, the thick oil viscosity reducer is prepared into an aqueous solution for use;

in the aqueous solution, the concentration of the thickened oil viscosity-reducing auxiliary agent in the aqueous solution is 0.001-0.1 wt%;

preferably, the method for using the thick oil viscosity reducer comprises the following steps:

and mixing the aqueous solution with the viscous oil viscosity reduction auxiliary agent to reduce the viscosity of the viscous oil viscosity reduction auxiliary agent.