Atomized agent and method for viscosity reduction and cold production of thick oil

Abstract

The application provides an atomized agent and a method for thickened oil viscosity reduction and cold production, and relates to the technical field of oil production.The atomized agent comprises the following components in parts by weight: 3-10 parts of a surfactant, and 1-3 parts of a dispersant; the surfactant comprises alkyl benzene sulfonate, a non-ionic surfactant and imidazole quaternary ammonium salt surfactant in a mass ratio of (50-65):(20-40):(10-15); wherein the non-ionic surfactant is obtained by the reaction of a fatty alcohol polyoxyethylene ether and guaiacol glycidyl ether. The atomized agent has good compatibility with nitrogen, good temperature resistance and salt resistance, can be used for the viscosity reduction of super-thickened oil, and can be used for the thickened oil cold production by mixing with nitrogen and atomization, so that the oil recovery can be efficiently improved.

Description

Technical Field

[0001] This application relates to the field of oil production technology, and in particular to an atomizing agent and a method for cold production of heavy oil with reduced viscosity. Background Technology

[0002] Chemical viscosity reduction in cold oil recovery involves significantly reducing the viscosity of heavy oil using viscosity reducers (mainly surfactants), followed by conventional oil recovery methods. However, ordinary viscosity reducers cannot effectively contact heavy oil and struggle to penetrate and disperse it within the reservoir under reservoir conditions, thus limiting their ability to improve oil recovery. Furthermore, ordinary viscosity reducers have a narrow applicability and are ineffective for extra-heavy oils. Nitrogen-assisted chemical viscosity reduction addresses this by using nitrogen to carry the viscosity reducer into the formation and porous media, allowing it to dissolve in the crude oil and effectively reduce its viscosity, enhance its fluidity, and improve oil recovery. However, research on nitrogen-assisted chemical viscosity reduction is currently limited. Patent CN111577228A provides a nitrogen atomization dispersion method for heavy oil cold recovery, using a dedicated atomization device to mix and atomize additives such as viscosity reducers and foaming agents with nitrogen, then injecting the mixture into the formation along with the nitrogen gas to achieve cold oil recovery. However, it uses ordinary viscosity reducers and foaming agents, which have poor compatibility with nitrogen and poor stability of the atomized droplets. In addition, ordinary viscosity reducers and foaming agents have poor temperature and salt resistance, resulting in limited improvement in crude oil recovery.

[0003] Therefore, there is currently a lack of a chemical additive that can be combined with nitrogen to achieve efficient cold extraction of heavy oil. Summary of the Invention

[0004] In order to overcome the defects and deficiencies in the existing technology, this application provides an atomizing agent and a method for cold extraction of heavy oil with reduced viscosity. The atomizing agent of this application has good compatibility with nitrogen and excellent temperature and salt resistance. It can be used to reduce the viscosity of extra-heavy oil. When mixed with nitrogen and atomized for cold extraction of heavy oil, it can achieve efficient improvement in crude oil recovery.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows: According to one aspect of this application, an atomizing agent is provided, comprising, by weight, the following components: 3-10 parts of surfactant and 1-3 parts of dispersant; wherein the surfactant comprises alkylbenzene sulfonate, nonionic surfactant, and imidazole quaternary ammonium salt surfactant in a mass ratio of (50-65):(20-40):(10-15); wherein... The nonionic surfactant is obtained by reacting fatty alcohol polyoxyethylene ether with guaiacol glycidyl ether.

[0006] This application selects three surfactants for compound use. This system has good compatibility with nitrogen and can form stable atomized droplets. After being injected into the formation together with nitrogen, the droplets diffuse rapidly with the nitrogen, covering a large area. This can effectively reduce the viscosity of heavy oil, fundamentally improve the fluidity of heavy oil, and increase crude oil recovery.

[0007] Furthermore, the nonionic surfactant is prepared by the following method: Add fatty alcohol polyoxyethylene ether and alkaline catalyst to a reaction vessel, stir and heat to 90-100℃, vacuum dehydrate for 30-40 min, then heat to 110-120℃, slowly add guaiacol glycidyl ether, keep the reaction temperature for 3-5 h after the addition is complete, cool to below 70℃, add glacial acetic acid to neutralize, filter, and the nonionic surfactant is obtained.

[0008] Furthermore, the preparation process of the above-mentioned nonionic surfactant includes the following limitations: The general structural formula of the fatty alcohol polyoxyethylene ether is: Where R represents a straight-chain or branched alkyl group with 12 to 18 carbon atoms, and n represents the number of additions to ethylene oxide, where n is an integer from 9 to 16; for example, the fatty alcohol polyoxyethylene ether can be dodecyl alcohol polyoxyethylene ether (9), tetradecyl alcohol polyoxyethylene ether (9), hexadecyl alcohol polyoxyethylene ether (9), octadecyl alcohol polyoxyethylene ether (9), dodecyl alcohol polyoxyethylene ether (10), tetradecyl alcohol polyoxyethylene ether (10), hexadecyl alcohol polyoxyethylene ether (10), octadecyl alcohol polyoxyethylene ether (10), dodecyl alcohol polyoxyethylene ether (16), tetradecyl alcohol polyoxyethylene ether (16), hexadecyl alcohol polyoxyethylene ether (16), octadecyl alcohol polyoxyethylene ether (16), etc., where the values ​​of 9, 10, 16, etc. in parentheses are the above-mentioned n; The molar ratio of the fatty alcohol polyoxyethylene ether and the guaiacol glycidyl ether is 1:(0.8~1.2). The alkaline catalyst is sodium hydroxide or potassium hydroxide, and the amount of catalyst used is 0.1 to 0.5% of the total mass of fatty alcohol polyoxyethylene ether and guaiacol glycidyl ether.

[0009] Furthermore, the alkylbenzene sulfonate is selected from alkylbenzene sulfonates of C18 to C30, such as octadecylbenzene sulfonate, eicosylbenzene sulfonate, dodecylbenzene sulfonate, tetradecylbenzene sulfonate, hexadecylbenzene sulfonate, octadecylbenzene sulfonate, triadecylbenzene sulfonate, etc., or it can be a combination of several, such as octadecyl / eicosylbenzene sulfonate, twentidecyl / twentidecylbenzene sulfonate, dodecyl / twentidecylbenzene sulfonate, tetradecyl / twentidecylbenzene sulfonate, hexadecyl / octadecylbenzene sulfonate, octadecyl / triadecylbenzene sulfonate; the salt is any one or a combination of sodium salt, potassium salt, and ammonium salt.

[0010] In a further embodiment, the imidazole quaternary ammonium salt surfactant is selected from any one or a combination of several of 1-dodecyl-3-methylimidazolium bromide, 1-tetradecyl-3-methylimidazolium chloride, 1-tetradecyl-3-methylimidazolium bromide, 1-tetradecyl-3-methylimidazolium hydrogen sulfate, 1-hexadecyl-3-methylimidazolium nitrate, and 1-octadecyl-3-methylimidazolium chloride.

[0011] This application provides the above-mentioned nonionic surfactant for use in combination with alkylbenzene sulfonate and imidazole quaternary ammonium salt surfactants. Compared with ordinary polyoxyethylene ether nonionic surfactants, the resulting system has better compatibility with nitrogen, is not easily broken under nitrogen atomization shear, has strong stability, and can significantly reduce the viscosity of heavy oil and improve the fluidity of heavy oil after entering the formation, thereby increasing the oil recovery rate. In addition, the nonionic surfactant can improve the system's resistance to high temperature and high salt.

[0012] Furthermore, the dispersant comprises dispersant A, which is selected from any one or a combination of several of stearic acid, sodium stearate, and zinc acetate.

[0013] In a further embodiment, the dispersant further comprises dispersant B, which is xylitol; the mass ratio of dispersant A to dispersant B is (70-100):(0-30).

[0014] The addition of dispersant A can improve the dispersibility of the components in the system and enhance the stability of the atomized droplets, thereby helping to improve crude oil recovery. In addition, studies have found that the combination of xylitol and dispersant A not only helps to further improve the stability of the atomized droplets, but also enhances the salt tolerance.

[0015] In a further embodiment, the atomizing agent also contains 1-3 parts of modified nanocellulose, which is obtained by modification with an aminosilane coupling agent and a hydroxyl-containing diallyl ether compound. The specific preparation method is as follows: (1) The aminosilane coupling agent is hydrolyzed in an alkaline solution with a pH of 8-10 at a mass ratio of 20-30 times, and then added to the ethanol dispersion of nanocellulose (mass concentration 5-10%) at a mass ratio of 1:(1-5). The mixture is reacted overnight at 60-70°C, and then washed with alcohol, water, and dried to obtain aminosilane coupling agent modified nanocellulose. (2) Mix aminosilane coupling agent modified nanocellulose with hydroxyl-containing diallyl ether compound, heat to 140-150℃, add hexamethylene diisocyanate and react for 2-3 hours to obtain the product.

[0016] Preferably, the above-mentioned preparation process of modified nanocellulose includes the following limitations: The aminosilane coupling agent is selected from at least one of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, and N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane; The hydroxyl-containing diallyl ether compound is selected from glycerol-A,A'-diallyl ether and / or 2,2-bis(allyloxymethyl)-1-butanol; The mass ratio of nanocellulose, aminosilane coupling agent, hydroxyl-containing diallyl ether compound, and hexamethylene diisocyanate is 1:(1.1~1.25):(0.85~0.95):(0.2~0.5); The alkaline solution is either sodium hydroxide solution or potassium hydroxide solution.

[0017] The addition of modified nanocellulose to the system in this application can further enhance the atomization system's resistance to agglomeration and sedimentation, and extend its underground migration distance. In addition, the addition of modified nanocellulose can also help improve the system's resistance to high temperature and high salinity, making it suitable for the development of high temperature and high salinity reservoirs.

[0018] According to another aspect of this application, a method for using the above-mentioned atomizing agent for viscosity reduction and cold extraction of heavy oil is provided, comprising the following steps: The atomizing agent is mixed with water to obtain a diluted solution. The diluted solution is then mixed with nitrogen and atomized before being injected into the formation. After injecting nitrogen, a slug is placed, the well is shut in, the well is allowed to simmer, and then the well is started for production.

[0019] Furthermore, the mass ratio of the atomizing agent to water is 1:(4-10), and the volume ratio of the atomizing agent to nitrogen is (0.01-0.05):1.

[0020] Furthermore, the water is any one of clean water, tap water, formation water, or mineralized water.

[0021] Furthermore, the injection rate of the diluent is 1–10 t / d, and the nitrogen injection rate is 3–5 × 10⁻⁶ t / d. 4 sm 3 / d.

[0022] Furthermore, the nitrogen injection rate in the nitrogen post-slug is 8–12 × 10⁻⁶. 4 sm 3 / d.

[0023] Furthermore, the well-sealing time is 10 to 14 days.

[0024] Furthermore, the above application method can be applied to heavy oil reservoirs with reservoir temperatures above 150℃, salinity not exceeding 300,000 mg / L, and crude oil viscosity exceeding 10,000 mPa·s.

[0025] Compared with the prior art, this application has the following beneficial effects: 1. The atomizing agent of this application has good compatibility with nitrogen and excellent temperature and salt resistance. It can be used to reduce the viscosity of extra-heavy oil. When mixed with nitrogen and atomized for cold extraction of heavy oil, it can achieve efficient improvement in crude oil recovery.

[0026] 2. The atomizing agent of this application selects three surfactants for compound use. This system has good compatibility with nitrogen and can form stable atomized droplets. After being injected into the formation together with nitrogen, it diffuses rapidly with nitrogen, covering a large area. It can effectively reduce the viscosity of heavy oil, fundamentally improve the fluidity of heavy oil, and improve crude oil recovery.

[0027] 3. The addition of modified nanocellulose to the atomizing agent in this application can further enhance the atomization system's resistance to agglomeration and sedimentation, extend the underground migration distance, and will not affect the foam performance of the system. In addition, the addition of modified nanocellulose also helps to improve the system's resistance to high temperature and high salt, making it suitable for the development of high temperature and high salt reservoirs. Attached Figure Description

[0028] Figure 1 This is the infrared spectrum of the nonionic surfactant in Example 1 of this application; Figure 2 This is the 1H NMR spectrum of the nonionic surfactant in Example 1 of this application. Detailed Implementation

[0029] To more clearly illustrate the overall concept of this application, a detailed description is provided below with reference to the accompanying drawings and embodiments. Numerous specific details are set forth in the following description to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described to avoid confusion with the invention.

[0030] Before further describing specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below; it should also be understood that the terminology used in the embodiments of the present invention is for describing specific embodiments and not for limiting the scope of protection of the present invention. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or according to the conditions recommended by the respective manufacturers. Preparation methods that do not specify specific methods are generally prepared using equipment or conventional methods well known in the art.

[0031] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0032] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. In addition to the specific methods, apparatus, and materials used in the embodiments, based on the knowledge of the prior art possessed by one of ordinary skill in the art and the description of this invention, any prior art methods, apparatus, and materials similar to or equivalent to those described, apparatus, and materials in the embodiments of this invention may be used to implement the present invention.

[0033] Unless otherwise specified, in the following embodiments, reagents or instruments whose manufacturers are not indicated are all conventional products that can be purchased commercially.

[0034] Unless otherwise stated, the experimental methods, detection methods and preparation methods disclosed in this invention all adopt conventional techniques in this technical field.

[0035] The present application will be further described below by way of specific embodiments.

[0036] Example 1 This embodiment provides an atomizing agent, which, by weight, comprises the following components: 3 parts surfactant and 1 part sodium stearate; The surfactant comprises sodium octadecylbenzenesulfonate, a nonionic surfactant, and 1-tetradecyl-3-methylimidazolium chloride in a mass ratio of 50:40:10; wherein, The nonionic surfactant was prepared by the following method: dodecyl alcohol polyoxyethylene ether (9) and sodium hydroxide were added to a reaction vessel, stirred and heated to 90°C, vacuum dehydrated for 30 min, then heated to 110°C, and guaiacol glycidyl ether was slowly added dropwise. After the addition was complete, the reaction was kept at the temperature for 3 h, cooled to below 70°C, neutralized with glacial acetic acid, and filtered to obtain the nonionic surfactant; the mass ratio of dodecyl alcohol polyoxyethylene ether (9), sodium hydroxide, and guaiacol glycidyl ether was 1:0.8:0.1. The reaction equations for the above nonionic surfactants are as follows: .

[0037] The structure of the obtained nonionic surfactant was identified.

[0038] like Figure 1 As shown, 2925cm -1 2855cm -1 The nearby peaks are the CH stretching vibration peaks in dodecyl alcohol polyoxyethylene ether, 1500-1600 cm⁻¹. -1 The presence of characteristic peaks in the benzene ring skeleton of guaiacol glycidyl ether indicates the successful preparation of a nonionic surfactant. For example... Figure 2 As shown, the peaks with chemical shifts of 6.8–7.0 ppm represent hydrogen atoms in the benzene ring skeleton, and the peaks with chemical shifts of 1.2–1.5 ppm represent hydrogen atoms on the methylene group in dodecyl alcohol polyoxyethylene ether. The combination of infrared spectroscopy and proton NMR spectroscopy confirms the successful preparation of the nonionic surfactant.

[0039] Example 2 This embodiment provides another atomizing agent, which, by weight, comprises the following components: 10 parts surfactant and 3 parts zinc acetate; The surfactant comprises sodium triacontylbenzenesulfonate, a nonionic surfactant, and 1-dodecyl-3-methylimidazole bromide in a mass ratio of 65:20:15; wherein, The nonionic surfactant was prepared by the following method: octadecyl alcohol polyoxyethylene ether (16) and sodium hydroxide were added to a reaction vessel, stirred and heated to 100°C, vacuum dehydrated for 40 min, then heated to 120°C, and guaiacol glycidyl ether was slowly added dropwise. After the addition was complete, the reaction was kept at the temperature for 5 h, cooled to below 70°C, neutralized with glacial acetic acid, and filtered to obtain the nonionic surfactant; the mass ratio of octadecyl alcohol polyoxyethylene ether (16), sodium hydroxide, and guaiacol glycidyl ether was 1:1.2:0.5.

[0040] Example 3 The difference from Example 2 is that the dispersant includes zinc acetate and xylitol in a mass ratio of 70:30.

[0041] Example 4 The difference from Example 2 is that the dispersant includes zinc acetate and xylitol in a mass ratio of 50:50.

[0042] Example 5 The difference from Example 2 is that the atomizing agent also includes 1 part of modified nanocellulose, which is prepared by the following method: γ-aminopropyltrimethoxysilane is hydrolyzed in 20 times its mass of sodium hydroxide solution at pH 10, and then added to an ethanol dispersion of nanocellulose (mass concentration 5%) at a mass ratio of 1:1. The mixture is reacted overnight at 60°C, then washed with alcohol, water, and dried to obtain aminosilane coupling agent modified nanocellulose; the aminosilane coupling agent modified nanocellulose is mixed with 2,2-bis(allyloxymethyl)-1-butanol, heated to 140°C, and hexamethylene diisocyanate is added and reacted for 2 hours to obtain the final product; the mass ratio of nanocellulose, γ-aminopropyltrimethoxysilane, 2,2-bis(allyloxymethyl)-1-butanol, and hexamethylene diisocyanate is 1:1.1:0.85:0.2.

[0043] Example 6 The difference from Example 2 is that the atomizing agent also includes 3 parts of modified nanocellulose, which is prepared by the following method: γ-aminopropyltrimethoxysilane is hydrolyzed in 20 times its mass of sodium hydroxide solution at pH 10, and then added to an ethanol dispersion of nanocellulose (mass concentration 10%) at a mass ratio of 1:5. The mixture is reacted overnight at 70°C, then washed with alcohol, water, and dried to obtain aminosilane coupling agent modified nanocellulose; the aminosilane coupling agent modified nanocellulose is mixed with 2,2-bis(allyloxymethyl)-1-butanol, heated to 150°C, and hexamethylene diisocyanate is added and reacted for 2 hours to obtain the final product; the mass ratio of nanocellulose, γ-aminopropyltrimethoxysilane, 2,2-bis(allyloxymethyl)-1-butanol, and hexamethylene diisocyanate is 1:1.25:0.95:0.5.

[0044] Example 7 The difference from Example 5 is that the modified nanocellulose is replaced with an equal amount of aminosilane coupling agent modified nanocellulose.

[0045] Example 8 The difference from Example 5 is that the modified nanocellulose is replaced with an equal amount of nanocellulose.

[0046] Comparative Example 1 The difference from Example 2 is that the surfactant includes sodium triacontylbenzenesulfonate, a nonionic surfactant, and 1-dodecyl-3-methylimidazole bromide in a mass ratio of 45:45:10, and the preparation method of the nonionic surfactant is the same as in Example 2.

[0047] Comparative Example 2 The difference from Example 2 is that the surfactant includes sodium triacontylbenzenesulfonate and a nonionic surfactant in a mass ratio of 65:20, and the preparation method of the nonionic surfactant is the same as in Example 2.

[0048] Comparative Example 3 The difference from Example 2 is that the surfactant includes sodium triacontylbenzenesulfonate and 1-dodecyl-3-methylimidazole bromide in a mass ratio of 65:15.

[0049] Comparative Example 4 The difference from Example 2 is that the nonionic surfactant in the surfactant is octadecyl alcohol polyoxyethylene ether (16).

[0050] Comparative Example 5 The difference from Example 2 is that the nonionic surfactant in the surfactant is prepared according to the preparation method provided in Example 1 of patent CN111203150A.

[0051] Experimental Example 1 The following tests were performed on the atomizing agents used in the above embodiments and comparative examples: (1) Viscosity reduction performance: Crude oil with initial viscosity of 15180 mPa.s and 54300 mPa.s (50℃) was used. The atomizing agent was added to tap water to prepare a 0.3% sample. The sample was mixed with crude oil at a mass ratio of 2:1. The viscosity reduction rate A / B was tested with reference to Q / SH10201519—2016 "General Technical Conditions for Heavy Oil Viscosity Reducers".

[0052] (2) High temperature resistance: The atomizing agent was mixed with tap water to prepare a 0.3% sample. After aging at 150℃ for 72h, the viscosity reduction rate C of crude oil at 54300mPa.s was tested according to the method in (1) above.

[0053] (3) Salt resistance: The simulated formation water with a total salinity of 300,000 mg / L and the atomizing agent were used to prepare a 0.3% sample. The viscosity reduction rate D of crude oil at 54,300 mPa·s was tested according to the method in (1) above.

[0054] The results are shown in Table 1 below.

[0055] Table 1. Atomizing Agent Performance

[0056] As shown in the table, the atomizing agent provided in this application has a high viscosity reduction rate for extra-heavy oil and excellent high-temperature and high-salinity resistance, making it suitable for the development of high-temperature and high-salinity oil reservoirs. Compared with Example 2, the proportions of the three surfactants in Comparative Example 1 were changed, only two surfactants were used in combination in Comparative Examples 2 and 3, a conventional nonionic surfactant was used in Comparative Example 4, and an existing nonionic surfactant was used in Comparative Example 5. The high-temperature and high-salinity resistance of these surfactants decreased. This indicates that the three surfactants in this application work synergistically to effectively reduce the viscosity of heavy oil, thereby achieving crude oil recovery, and also improving the high-temperature and high-salinity resistance of the system.

[0057] Furthermore, in Example 3, zinc acetate and xylitol were used as dispersants, which improved the salt resistance to a certain extent. This indicates that the combination of the two dispersants in a specific ratio can also improve the salt resistance of the system to a certain degree. In Examples 5 and 6, the addition of modified nanocellulose improved both the high temperature resistance and salt resistance of the system, while the high temperature and salt resistance of the systems obtained in Examples 7 and 8 showed almost no improvement. This demonstrates that the addition of specific modified nanocellulose to the system in this application has the effect of improving the high temperature and salt resistance of the system.

[0058] Experimental Example 2 In the above embodiments and comparative examples, the atomizing agent and tap water were mixed at a mass ratio of 1:10, and then mixed with nitrogen gas (at a volume ratio of atomizing agent to nitrogen gas of 1:0.05) and atomized to obtain nitrogen droplets. The particle size D of the droplets was tested at 0 min. 50 (0), and particle size D at 60 min 50 (60) Calculate the particle size change rate using the following formula: ; The total mass M of the nitrogen droplets after atomization and the deposition mass m after 60 minutes were measured, and the deposition rate was calculated using the following formula: .

[0059] The test results are shown in Table 2 below.

[0060] Table 2. Atomized droplet size

[0061] As shown in the table above, the nitrogen droplets formed after mixing and atomizing the atomizing agent provided in this application with nitrogen gas exhibit relatively low particle size change and sedimentation rate within 60 minutes, demonstrating good stability. Compared to the examples, the nitrogen droplets formed in Comparative Examples 1-5 show increased particle size change and sedimentation rate. This indicates that the three surfactants in this application work synergistically to help form stable nitrogen droplets with nitrogen gas, which facilitates rapid diffusion with nitrogen gas in the formation, thereby expanding the swept area and improving oil recovery. Furthermore, the nitrogen droplets formed in Examples 3, 5, and 6 show improved stability compared to Example 2. This indicates that adding xylitol as a dispersant and adding modified nanocellulose can improve the stability of nitrogen droplets to a certain extent, further enhancing oil recovery.

[0062] Experimental Example 3 The atomizing agents prepared in the above examples and comparative examples were used for viscosity reduction and cold recovery of heavy oil, as follows: An oil reservoir in a certain oilfield has a burial depth of 1500–1800 m, a permeability of 44–75 mD, and a crude oil viscosity of 5800–15600 mPa·s. The atomizing agent from Example 2 above was diluted with water to form a 10% diluent, which was then mixed with nitrogen (the volume ratio of atomizing agent to nitrogen was 0.03:1) and atomized before being injected into the formation. The injection rate of the diluent was 5 t / d, the injection volume was 10 t, and the nitrogen injection rate was 5 × 10⁻⁶ m / d. 4 sm 3 / d, injection volume is 5×10 4 sm 3 Then, nitrogen was injected into the post-slug plug at a rate of 5 × 10⁻⁶. 4 sm 3 / d, injection volume is 10×10 4 sm 3 After injection, the well was shut in and left to simmer for 10 days before resuming production. The oilfield currently produces 1.43 tons of crude oil per day, with a peak production of 6.64 tons per day after the project. During the effective production period, it operated for 187 days, producing a cumulative total of 561 tons of oil, achieving good development results.

[0063] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, this application is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of this application without departing from the scope of this application should be within the protection scope of this application.

Claims

1. An atomizing agent, characterized in that, By weight, it comprises the following components: 3-10 parts surfactant and 1-3 parts dispersant; wherein the surfactant comprises alkylbenzene sulfonate, nonionic surfactant, and imidazole quaternary ammonium salt surfactant in a mass ratio of (50-65):(20-40):(10-15); The preparation method of the nonionic surfactant includes the following steps: Add fatty alcohol polyoxyethylene ether and alkaline catalyst into a reaction vessel, stir and heat to 90-100℃, dehydrate under vacuum, then heat to 110-120℃, slowly add guaiacol glycidyl ether, keep the reaction temperature for 3-5 hours after the addition is complete, cool to below 70℃, add glacial acetic acid to neutralize, filter, and the nonionic surfactant is obtained.

2. The atomizing agent according to claim 1, characterized in that, The alkylbenzene sulfonate is selected from C18 to C30 alkylbenzene sulfonates.

3. The atomizing agent according to claim 1, characterized in that, The imidazole quaternary ammonium salt surfactant is selected from any one or a combination of several of the following: 1-dodecyl-3-methylimidazolium bromide, 1-tetradecyl-3-methylimidazolium chloride, 1-tetradecyl-3-methylimidazolium bromide, 1-tetradecyl-3-methylimidazolium hydrogen sulfate, 1-hexadecyl-3-methylimidazolium nitrate, and 1-octadecyl-3-methylimidazolium chloride.

4. The atomizing agent according to claim 1, characterized in that, The dispersant is selected from any one or a combination of several of stearic acid, sodium stearate, and zinc acetate.

5. The atomizing agent according to any one of claims 1-4, characterized in that, The atomizing agent also contains 1 to 3 parts of modified nanocellulose.

6. The atomizing agent according to claim 5, characterized in that, The modified nanocellulose was obtained by modification with an aminosilane coupling agent and a hydroxyl-containing diallyl ether compound.

7. A method for using the atomizing agent according to any one of claims 1-6 for cold extraction of heavy oil with reduced viscosity, characterized in that, Includes the following steps: The atomizing agent is mixed with water to obtain a diluted solution. The diluted solution is then mixed with nitrogen and atomized before being injected into the formation. After injecting nitrogen, a slug is placed, the well is shut in, the well is shut in and allowed to simmer, and then the well is started for production.

8. The method according to claim 7, characterized in that, The mass ratio of the atomizing agent to water is 1:(4-10).

9. The method according to claim 7, characterized in that, The volume ratio of atomizing agent to nitrogen is (0.01~0.05):1.

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