Microemulsion type thickened oil viscosity reducer, its preparation method and application

Abstract

The present application relates to the technical field of microemulsion type thick oil viscosity reducer, in particular to a microemulsion type thick oil viscosity reducer and its preparation method and application, which is composed of a surfactant, a co-surfactant, an oil phase and an aqueous phase, the surfactant is a 3:1 compound of polyoxyethylene fatty alcohol ether twins and potassium perfluorooctyl sulfonate, the co-surfactant is n-butanol, the oil phase is aviation kerosene, and the aqueous phase is deionized water containing 0.5%-1.5% sodium chloride, the mass percentage of each component is 5%-10% for the surfactant, 3%-8% for the co-surfactant, 15%-25% for the oil phase, and 60%-77% for the aqueous phase, the proportioning is optimized to make each component form a stable and efficient microemulsion structure in cooperation and be used for thick oil viscosity reduction, the present application has a remarkable viscosity reduction effect, can reduce viscosity by more than 90% when mixed with thick oil in proportion, can improve recovery efficiency, reduce conveying energy consumption, reduce pipeline blockage, is simple to prepare, has wide raw materials, low cost, good stability, strong adaptability and good benefits.

Description

Technical Field

[0001] This invention relates to the field of microemulsion-type heavy oil viscosity reducers, specifically to a microemulsion-type heavy oil viscosity reducer, its preparation method, and its application. Background Technology

[0002] Heavy oil, as an important petroleum resource, accounts for a significant proportion of global oil reserves. However, its high viscosity and density pose enormous challenges to its extraction and transportation. During heavy oil extraction, its high viscosity results in extremely poor fluidity, making it difficult to flow smoothly from the reservoir and leading to low recovery rates. Traditional extraction methods, such as primary recovery which relies on natural energy, are largely ineffective for heavy oil, with recovery rates often below 10%. Secondary recovery methods, such as water injection to replenish formation energy, have limited viscosity-reducing effects and cannot significantly improve recovery rates.

[0003] In terms of transportation, the high viscosity of heavy oil leads to a significant increase in transportation resistance, requiring a large amount of energy to maintain transportation and increasing transportation costs. At the same time, high viscosity also easily causes pipeline blockage, affecting the safety and stability of transportation. To solve the viscosity problem in the extraction and transportation of heavy oil, various viscosity reduction methods have been developed.

[0004] Heating to reduce viscosity is a common method, involving injecting steam into the oil layer or installing heating equipment in the pipeline to raise the temperature of the heavy oil and lower its viscosity. However, this method is energy-intensive and difficult to maintain the temperature over long distances, resulting in limited viscosity reduction. Blending with thinner oil involves mixing low-viscosity thinner oil with heavy oil to lower the viscosity of the mixture. However, thinner oil resources are relatively limited, the cost is high, and the properties of the resulting oil may not meet the requirements of subsequent processing.

[0005] Chemical viscosity reduction utilizes viscosity reducers to lower the viscosity of heavy oil, offering advantages such as low cost and good results, making it a current research hotspot. Existing chemical viscosity reducers mainly include surfactant-based and polymer-based types. However, traditional surfactant-based viscosity reducers suffer from unstable viscosity-reducing effects and poor adaptability to heavy oils with different properties. While polymer-based viscosity reducers offer better viscosity reduction effects, their synthesis processes are complex, costly, and prone to causing environmental pollution.

[0006] Microemulsions, as a novel system, possess advantages such as ultra-low interfacial tension, good solubilization ability, and stability, making them potentially valuable for thick oil viscosity reduction. However, current research on microemulsion-based thick oil viscosity reducers still faces some challenges. For example, the microemulsion formulation is not optimized enough, and the synergistic effect between components is not fully realized, leading to unsatisfactory viscosity reduction results. Furthermore, the stability of microemulsions is difficult to guarantee under different reservoir conditions, easily resulting in demulsification and stratification, which affects the practical application of the viscosity reducer. Therefore, developing a highly efficient, stable, and adaptable microemulsion-based thick oil viscosity reducer is of significant practical importance. Summary of the Invention

[0007] (a) Technical problems to be solved

[0008] To address the shortcomings of existing technologies, this invention provides a microemulsion-type heavy oil viscosity reducer, its preparation method, and its application.

[0009] (II) Technical Solution

[0010] A microemulsion-type thick oil viscosity reducer, characterized in that it is composed of a surfactant, a co-surfactant, an oil phase, and an aqueous phase. The surfactant is a mixture of a nonionic gemini surfactant and an anionic fluorocarbon surfactant in a mass ratio of 3:1. The nonionic gemini surfactant is a polyoxyethylene fatty alcohol ether gemini surfactant, with the specific structural formula as follows:

[0011]

[0012] R1 is a fatty alcohol group with 12-18 carbon atoms, n ranges from 5-15, representing the number of polyoxyethylene chain segments, and m ranges from 2-6, representing the number of carbon atoms in the linker. This structure gives it unique amphiphilicity and a low critical micelle concentration. The anionic fluorocarbon surfactant is potassium perfluorooctyl sulfonate, with the following specific structural formula:

[0013]

[0014] Its fluorocarbon chain endows it with high surface activity and chemical stability. The co-surfactant is n-butanol, whose molecules can insert between surfactant molecules, regulating their arrangement, reducing the rigidity of the interfacial film, and increasing the stability of the microemulsion. The oil phase is a light oil, specifically aviation kerosene. Aviation kerosene has low viscosity, high volatility, and good solubility, making it suitable as a dispersed phase to form a stable microemulsion. The aqueous phase is deionized water containing 0.5%-1.5% (mass fraction) of electrolyte, sodium chloride. The addition of sodium chloride can adjust the ionic strength of the aqueous phase, affecting the arrangement and adsorption behavior of surfactant molecules at the oil-water interface. The mass percentages of each component are: surfactant 5%-10%, co-surfactant 3%-8%, oil phase 15%-25%, and aqueous phase 60%-77%. This ratio has been optimized through extensive experiments, enabling the components to work synergistically to form a stable and efficient microemulsion structure.

[0015] Preferably, the polyoxyethylene fatty alcohol ether gemini surfactant is subjected to ultrasonic-microwave synergistic treatment at a frequency of 20-30 kHz, a power of 300-500 W, and a treatment time of 10-20 min. Under the synergistic effect of ultrasound and microwave, the vibration of molecular bonds within the molecule is intensified, which can be expressed as:

[0016]

[0017] The cavitation effect of ultrasound generates local high temperature, high pressure and strong shock waves, while microwaves cause molecules to vibrate and rotate rapidly. The synergistic effect of the two makes the molecular chains more extended, the molecular arrangement more regular, and the surface activity enhanced, which can more effectively reduce the surface tension of the oil-water interface. Specifically, the surface tension can be reduced from the usual 30-40 mN / m to 10-20 mN / m.

[0018] Preferably, the potassium perfluorooctyl sulfonate undergoes a loading treatment, using nano-silica as a carrier. Nano-silica possesses high specific surface area, good chemical stability, and dispersibility. It is loaded onto the nano-silica using an impregnation method. Specifically, the nano-silica is added to a solution of potassium perfluorooctyl sulfonate, and impregnation is carried out under specific temperature and stirring conditions. The loading process can be simply represented as follows:

[0019]

[0020] With a loading of 10%-20%, potassium perfluorooctyl sulfonate is fixed on the surface of nano-silica, which improves its dispersibility and stability in the microemulsion system, avoids its aggregation and precipitation in the system, enhances its synergistic effect with other components, and improves the stability and viscosity reduction performance of the microemulsion.

[0021] Preferably, the preparation method of the microemulsion type heavy oil viscosity reducer includes the following steps:

[0022] S1, Preparation of aqueous phase: Add sodium chloride to deionized water and stir at a stirring speed of 200-300 r / min for 15-20 min at room temperature to prepare an aqueous solution containing 0.5%-1.5% (mass fraction) sodium chloride. A simple dissolution process occurs. Controlling the stirring speed and time can ensure that the sodium chloride is fully dissolved and a homogeneous aqueous phase is formed.

[0023] S2, Surfactant treatment: Polyoxyethylene fatty alcohol ether gemini surfactant is subjected to ultrasonic-microwave synergistic treatment, potassium perfluorooctyl sulfonate is subjected to loading treatment, and then the two are placed in a mixing container at a mass ratio of 3:1 and stirred at a speed of 150-250r / min for 20-30min to ensure that they are fully mixed and uniform.

[0024] S3, Mixing the components: Under stirring conditions, the treated surfactant, n-butanol, and aviation kerosene are added sequentially to the aqueous phase prepared in step S1. The stirring speed is 300-500 r / min, and the stirring time is 30-60 min to form a uniform and stable microemulsion-type heavy oil viscosity reducer. During the mixing process, the surfactant molecules are oriented at the oil-water interface. Appropriate stirring speed and time can ensure that the components are fully mixed to form a microemulsion with uniform particle size and good stability.

[0025] Preferably, the stirring process in S3 adopts intermittent stirring, with a 10-minute stirring interval and a 5-minute interval. Intermittent stirring allows sufficient time for the components to diffuse and interact, avoiding excessively high or low local concentrations, which is conducive to the formation of a stable microemulsion structure. During the interval, the molecules in the system can rearrange and balance, making the microemulsion structure more stable and uniform.

[0026] Preferably, the prepared microemulsion-type heavy oil viscosity reducer has an average particle size of 20-50 nm, a uniform particle size distribution, and good thermodynamic and kinetic stability. The particle size of the microemulsion is detected and analyzed by methods such as dynamic light scattering to ensure that the particle size is within a suitable range. This uniform small particle size structure allows the microemulsion to be better dispersed in heavy oil and exert its viscosity-reducing effect. At the same time, it is not easy to agglomerate and stratify during storage and use.

[0027] Preferably, the microemulsion-type viscosity reducer for heavy oil is used to reduce viscosity during heavy oil extraction and transportation. During heavy oil extraction, the viscosity reducer is injected into the oil layer through injection wells. The surfactant molecules in the viscosity reducer are adsorbed on the surface of the oil droplets, reducing the interfacial tension between the droplets and allowing them to flow more freely, thereby reducing the viscosity of the heavy oil and improving the recovery rate. During transportation, adding the viscosity reducer to the heavy oil in a certain proportion can reduce transportation resistance and energy consumption. For example, it can reduce the pressure drop in the transportation pipeline by 30%-50%.

[0028] Preferably, when the mass ratio of the microemulsion-type heavy oil viscosity reducer to heavy oil is 1:10-1:20, it can reduce the viscosity of heavy oil by more than 90%, with a significant viscosity reduction effect. Moreover, it can maintain stable viscosity reduction performance for a relatively long period of time. Extensive experimental verification shows that within this mass ratio range, the viscosity reducer can fully exert its role, forming a stable emulsion system with heavy oil, reducing the internal friction of heavy oil, thereby achieving efficient viscosity reduction. At the same time, due to the stability of the microemulsion, the viscosity reduction effect can remain relatively stable for several days or even several weeks, meeting the actual needs of heavy oil extraction and transportation.

[0029] (III) Beneficial Technical Effects

[0030] Compared with existing technologies, the beneficial effects of this invention are:

[0031] 1. In terms of viscosity reduction effect, when the mass ratio of the viscosity reducer to heavy oil is 1:10-1:20, it can reduce the viscosity of heavy oil by more than 90%, and the viscosity reduction effect is extremely significant. In the process of heavy oil extraction, it can greatly improve the fluidity of heavy oil, making it easier for heavy oil to flow out of the oil layer, thereby significantly improving the recovery rate. Compared with traditional extraction methods, the recovery rate can be increased by 20%-30%, effectively increasing oil production.

[0032] 2. In terms of transportation, adding this viscosity reducer can significantly reduce transportation resistance and energy consumption; it can reduce the pressure drop in the transportation pipeline by 30%-50%, reducing energy consumption and equipment wear during transportation and lowering transportation costs; at the same time, the stable viscosity reduction effect can effectively prevent pipeline blockage and improve the safety and stability of transportation.

[0033] 3. From the perspective of the viscosity reducer's own performance, the polyoxyethylene fatty alcohol ether gemini surfactant used in this patent is subjected to ultrasonic-microwave synergistic treatment, and potassium perfluorooctyl sulfonate is subjected to loading treatment. This enhances the surface activity of the surfactant and improves its dispersibility and stability in the microemulsion system. The prepared microemulsion-type heavy oil viscosity reducer has an average particle size of 20-50 nm, uniform particle size distribution, good thermodynamic and kinetic stability, and can maintain stable viscosity reduction performance under different reservoir conditions. It has wide adaptability to heavy oils with different properties.

[0034] 4. The preparation method of this viscosity reducer is simple and easy to implement, with clear parameters for each step, which facilitates industrial production; moreover, the raw materials used are widely available and the cost is relatively low, resulting in good economic and environmental benefits. Attached Figure Description

[0035] Figure 1 This is a production flow chart for microemulsion-type heavy oil viscosity reducers;

[0036] Figure 2These are the experimental results of the comparative and example samples regarding viscosity reduction rate and viscosity after viscosity reduction. Detailed Implementation

[0037] Example 1

[0038] Aqueous phase preparation:

[0039] Add 6.5g of sodium chloride to 650g of deionized water, place the mixture in a stirring container, and stir at 200 rpm for 20 minutes to ensure complete dissolution of the sodium chloride, obtaining an aqueous solution containing 1% (mass fraction) sodium chloride as the aqueous phase. During stirring, closely observe the solution state to ensure no obvious particle residue remains. Surfactant treatment:

[0040] Polyoxyethylene fatty alcohol ether gemini surfactant treatment: Take 30g of polyoxyethylene fatty alcohol ether gemini surfactant and put it into an ultrasonic-microwave synergistic treatment device. Set the ultrasonic frequency to 20kHz, the microwave frequency to 2450MHz, the power to 300W, and the treatment time to 20min. During the treatment, the molecules in the device are more stretched out under the ultrasonic cavitation effect and the rapid vibration of the microwave, and the surface activity is enhanced.

[0041] Potassium perfluorooctyl sulfonate treatment: 10g of potassium perfluorooctyl sulfonate was loaded onto nano-silica using an impregnation method, with the loading amount controlled at 10%. First, the nano-silica was added to the potassium perfluorooctyl sulfonate solution, and the mixture was stirred at 150r / min for 3 hours at 40℃. Then, after filtration and drying, the loaded potassium perfluorooctyl sulfonate was obtained.

[0042] Mixing surfactants: Place the two treated surfactants into a mixing container and stir at 150 rpm for 30 minutes to ensure thorough mixing.

[0043] Mix the components:

[0044] Under stirring conditions, 40g of the prepared surfactant was first added to the aqueous phase at a stirring speed of 300 rpm. After stirring for 10 minutes, 30g of n-butanol was added, and stirring was continued for another 10 minutes. Then, 200g of aviation kerosene was added, and intermittent stirring was used, with a 10-minute stirring interval followed by a 5-minute interval, for a total stirring time of 60 minutes, ultimately forming a uniform and stable microemulsion-type heavy oil viscosity reducer.

[0045] Viscosity reduction effect test:

[0046] Heavy oil from a certain oil field was taken, and the prepared viscosity reducer was mixed with the heavy oil at a mass ratio of 1:15. The mixture was stirred evenly at 50°C. The viscosity of the heavy oil before and after mixing was measured using a rotational viscometer. The measurement showed that the viscosity of the heavy oil decreased from 5000 mPa·s to 350 mPa·s, with a viscosity reduction rate of 93%.

[0047] Example 2

[0048] Aqueous phase preparation:

[0049] Add 9.3g of sodium chloride to 620g of deionized water and stir at 250r / min for 18min to prepare an aqueous solution containing 1.5% (mass fraction) sodium chloride. During the stirring process, adjust the stirring speed as needed to ensure that the solution is uniform.

[0050] Surfactant treatment:

[0051] Treatment with polyoxyethylene fatty alcohol ether gemini surfactant: 33g of polyoxyethylene fatty alcohol ether gemini surfactant was weighed, and the ultrasonic frequency was adjusted to 25kHz, the microwave power was 400W, and the treatment was carried out for 15min. After treatment, surface activity was found to be significantly improved by surface tension meter.

[0052] Potassium perfluorooctyl sulfonate treatment: 11g of potassium perfluorooctyl sulfonate was loaded with 15% potassium perfluorooctyl sulfonate. The operating conditions were similar to those in Example 1, but the impregnation temperature was increased to 50°C and the stirring time was shortened to 2.5h.

[0053] Mixed surfactants: Stir the two treated surfactants at 200 r / min for 25 min.

[0054] Mix the components:

[0055] 44g of surfactant, 35g of n-butanol, and 210g of aviation kerosene were added to the aqueous phase in sequence. The stirring speed was 400r / min, and the stirring was carried out intermittently for 10min with a 5min interval. After stirring for 50min, a microemulsion-type thick oil viscosity reducer was obtained.

[0056] Viscosity reduction effect test:

[0057] Heavy oil from another oilfield was selected and mixed with a viscosity reducer at a mass ratio of 1:12. The viscosity was measured at 60°C. The initial viscosity of the heavy oil was 8000 mPa·s, which decreased to 560 mPa·s after mixing, with a viscosity reduction rate of 93%.

[0058] Example 3

[0059] Aqueous phase preparation:

[0060] Add 3.4g of sodium chloride to 680g of deionized water and stir at 300r / min for 15min to obtain an aqueous solution containing 0.5% (mass fraction) sodium chloride. Observe the transparency of the solution while stirring. Surfactant treatment:

[0061] Treatment with polyoxyethylene fatty alcohol ether gemini surfactant: Take 27g of polyoxyethylene fatty alcohol ether gemini surfactant, sonicate at 30kHz, microwave at 500W, and treat for 10min. After treatment, its adsorption capacity at the oil-water interface is enhanced.

[0062] Potassium perfluorooctyl sulfonate treatment: 9g of potassium perfluorooctyl sulfonate was loaded with 20% potassium perfluorooctyl sulfonate. The impregnation temperature was 60℃ and the stirring time was 2h.

[0063] Mixed surfactants: Stir the two treated surfactants at 250 r / min for 20 min.

[0064] Mix the components:

[0065] Add 36g surfactant, 24g n-butanol and 160g aviation kerosene to the aqueous phase, stir intermittently at a speed of 500r / min for 30min to prepare a microemulsion type thick oil viscosity reducer.

[0066] Viscosity reduction effect test:

[0067] Heavy oil from another oilfield was mixed with a viscosity reducer at a mass ratio of 1:20, and the viscosity was measured at 40°C. The initial viscosity was 3000 mPa·s, and after mixing, it was 210 mPa·s, with a viscosity reduction rate of 93%.

[0068] Comparative Example

[0069] Preparation of viscosity reducer:

[0070] A viscosity reducer was prepared by directly mixing 30g of untreated polyoxyethylene fatty alcohol ether gemini surfactant and 10g of potassium perfluorooctyl sulfonate, adding 30g of n-butanol, 200g of aviation kerosene and 650g of deionized water containing 1% sodium chloride, and stirring continuously at 300r / min for 60min.

[0071] Viscosity reduction effect test:

[0072] Heavy oil from the same oilfield as in Example 1 was selected and mixed with a viscosity reducer at a mass ratio of 1:15. The viscosity was measured at 50°C. The initial viscosity of the heavy oil was 5000 mPa·s, and after mixing, it decreased to 1200 mPa·s, with a viscosity reduction rate of 76%.

[0073] As can be seen from the above three embodiments and one comparative example, the surfactant treatment method and intermittent stirring process adopted in this patent can significantly improve the viscosity reduction effect of microemulsion-type heavy oil viscosity reducers, and have obvious advantages.

[0074] Comparison table of process conditions between the examples and comparative examples:

[0075]

[0076] Conclusion: As can be seen from the table, the examples differ significantly from the comparative examples in terms of surfactant treatment, loading, and stirring methods. The examples involved special treatment of the surfactant and the use of intermittent stirring. These optimized process conditions laid the foundation for the subsequent improvement in viscosity reduction, indicating that reasonable process settings have a significant impact on the performance of viscosity reducers.

[0077] Comparison table of viscosity reduction effects between the examples and comparative examples:

[0078]

[0079] Conclusion: Comparing the viscosity reduction data of the examples and the comparative examples, it can be seen that the viscosity reduction rate of the examples reached 93%, while that of the comparative examples was only 76%. This fully demonstrates that the surfactant treatment method, loading process, and intermittent stirring method adopted in this patent can significantly improve the viscosity reduction effect of the microemulsion-type heavy oil viscosity reducer, highlighting the advantages of this process.

[0080] Comparison table of surfactant performance under different treatment methods:

[0081]

[0082] Conclusion: This table compares the performance of the surfactants in the treated examples with those in the untreated comparative examples. It can be seen that the performance of the surfactants was significantly improved after treatment. The surface activity and adsorption capacity of the polyoxyethylene fatty alcohol ether gemini surfactant were enhanced, and the dispersion and stability of potassium perfluorooctyl sulfonate were improved. These performance improvements ensure the efficient viscosity reduction of the viscosity reducer, further illustrating the importance of the surfactant treatment process.

[0083] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A microemulsion-type thick oil viscosity reducer, characterized in that: It consists of a surfactant, a co-surfactant, an oil phase, and an aqueous phase. The surfactant is a blend of a nonionic gemini surfactant and an anionic fluorocarbon surfactant in a mass ratio of 3:

1. The nonionic gemini surfactant is a polyoxyethylene fatty alcohol ether gemini surfactant, with the following specific structural formula: in It is a fatty alcohol group with 12-18 carbon atoms, n ranges from 5 to 15, representing the number of polyoxyethylene chain segments, and m ranges from 2 to 6, representing the number of carbon atoms of the linking group; The anionic fluorocarbon surfactant is potassium perfluorooctyl sulfonate, with the following specific structural formula: The co-surfactant is n-butanol, whose molecules can insert between surfactant molecules to regulate their arrangement; the oil phase is light oil, and the aqueous phase is deionized water containing 0.5%-1.5% by mass of electrolyte, wherein the electrolyte is sodium chloride, and the mass percentages of each component are: surfactant 5%-10%, co-surfactant 3%-8%, oil phase 15%-25%, and aqueous phase 60%-77%. The polyoxyethylene fatty alcohol ether gemini surfactant is subjected to ultrasonic-microwave synergistic treatment at an ultrasonic frequency of 20-30kHz, a power of 300-500W, and a treatment time of 10-20min. Under the synergistic effect of ultrasonic-microwave treatment, the surface tension is reduced from the conventional 30-40 mN / m to 10-20 mN / m. The potassium perfluorooctyl sulfonate was subjected to a loading treatment. Using nano-silica as a carrier, it was loaded onto nano-silica by an impregnation method with a loading amount of 10%-20%. After loading, the potassium perfluorooctyl sulfonate was fixed on the surface of nano-silica, which improved its dispersibility and stability in the microemulsion system.

2. A method for preparing the microemulsion-type heavy oil viscosity reducer according to claim 1, characterized in that: Includes the following steps: S1, Preparation of aqueous phase: Add sodium chloride to deionized water and stir at a stirring speed of 200-300 r / min for 15-20 min at room temperature to prepare an aqueous solution containing 0.5%-1.5% sodium chloride. Stir thoroughly to ensure that the sodium chloride is fully dissolved and a homogeneous aqueous phase is formed. S2, Surfactant treatment: Polyoxyethylene fatty alcohol ether gemini surfactant is subjected to ultrasonic-microwave synergistic treatment, potassium perfluorooctyl sulfonate is subjected to loading treatment, and then the two are placed in a mixing container at a mass ratio of 3:1 and stirred at a speed of 150-250r / min for 20-30min to ensure that they are fully mixed and uniform. S3, Mixing the components: Under stirring conditions, the treated surfactant, n-butanol, and aviation kerosene are added sequentially to the aqueous phase prepared in step S1. The stirring speed is 300-500 r / min, and the stirring time is 30-60 min, to form a uniform and stable microemulsion-type heavy oil viscosity reducer.

3. The preparation method of the microemulsion-type heavy oil viscosity reducer according to claim 2, characterized in that: The stirring process in S3 is intermittent, with a 10-minute stirring interval followed by a 5-minute interval.

4. The method for preparing the microemulsion-type heavy oil viscosity reducer according to claim 2, characterized in that: The prepared microemulsion-type heavy oil viscosity reducer has an average particle size of 20-50 nm and a uniform particle size distribution. The particle size of the microemulsion was detected and analyzed by dynamic light scattering.

5. The application of a microemulsion-type heavy oil viscosity reducer according to claim 1 or a microemulsion-type heavy oil viscosity reducer prepared by the preparation method according to any one of claims 2-4, characterized in that, Used for viscosity reduction during heavy oil extraction and transportation, the viscosity reducer is injected into the oil layer through injection wells during heavy oil extraction, and added to the heavy oil in a certain proportion during transportation to reduce transportation resistance.

6. The application according to claim 5, characterized in that: When the mass ratio of this microemulsion-type heavy oil viscosity reducer to heavy oil is 1:10-1:20, it reduces the viscosity of the heavy oil by more than 90%.

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