Oil-in-water nanoemulsion loaded with corrosion inhibitor, its preparation method and application

Abstract

The present invention relates to the field of corrosion inhibitors, and discloses an oil-in-water nanoemulsion loaded with a corrosion inhibitor, a preparation method thereof, and an application thereof. The nanoemulsion loaded with the corrosion inhibitor comprises a main corrosion inhibitor, a surfactant, a solvent oil, and water; wherein, the main corrosion inhibitor is an oil-soluble corrosion inhibitor. By means of the nanoemulsion loaded with the corrosion inhibitor, the main corrosion inhibitor is encapsulated by the nanoemulsion to improve its water solubility, greatly improve the diffusion performance and effective content of the corrosion inhibitor in an aqueous medium, improve the corrosion inhibition effect, and have significant advantages under the condition of coexistence of oil and water. At the same time, the flash point of the nanoemulsion loaded with the corrosion inhibitor provided by the present invention is greatly increased compared with the flash point of the original corrosion inhibitor, improving the safety and stability of the corrosion inhibitor during use.

Description

Technical Field

[0001] The present invention relates to the field of corrosion inhibitors, and particularly to an oil-in-water nanoemulsion loaded with a corrosion inhibitor, a preparation method thereof, and an application thereof. Background Art

[0002] In the field of oil and gas gathering and transportation, the pipeline transportation medium is mostly a mixture of highly corrosive oil, water, gas, etc. Therefore, it is generally necessary to add a corrosion inhibitor to control corrosion. Oil-soluble corrosion inhibitors are widely used in the field of oil and gas gathering and transportation due to their wide variety of substances and excellent corrosion inhibition effects.

[0003] However, oil-soluble corrosion inhibitors currently generally have the following problems: First, since oil-soluble corrosion inhibitor products usually use substances such as alkanes, aromatics, and alcohols as solvents (CN103450865A), and the content of the solvent is generally higher than 50 wt%. The use of a large amount of solvent not only increases the production raw material cost, but also increases the safety risk of the entire industrial chain. Especially for the oil and gas industry, a series of related problems such as storage, use, and environmental protection will be faced. Because essentially these organic solvents generally have the defect of low flash point. For example, the flash point of No. 0 diesel is usually 55°C, while the temperature at the natural gas wellhead is generally around 80°C. In addition, organic solvents also face a series of problems such as volatility, toxicity, and post-treatment.

[0004] Secondly, safely and efficiently transporting natural gas is a basic prerequisite for the natural gas gathering and transportation system. The inside of the pipeline must be kept clean, and the generation of sediments should be avoided. However, the actual industrial production application shows that the probability of deposition and even blockage in the pipeline due to the use of some oil-soluble corrosion inhibitors has increased significantly. This is because many oil-soluble corrosion inhibitor main agents themselves are viscous pastes (products sold on the market are generally diluted with oil to reduce viscosity). Under the complex working conditions of the pipeline, due to the fundamental property of poor dispersion in water, the main agent and the oil phase may separate. With the discharge of some other solid particles and oilfield chemicals in the gas well, the corrosion inhibitor main agent undergoes intricate physical and chemical interactions with these discharged substances, ultimately resulting in deposition and even blockage.

[0005] Finally, when oil-soluble corrosion inhibitors are applied in gas fields with associated condensate oil, an important production problem is faced. In the field of oil and gas gathering and transportation, the corrosion of metal materials mainly occurs at the position where the pipeline accumulates liquid. This is because the presence of accumulated liquid (water) will accelerate the electrochemical mass transfer process of corrosion. Therefore, the corrosion control of the water phase is the main purpose of the corrosion inhibitor. However, since organic corrosion inhibitors are more easily dissolved and dispersed in the "oil phase", under conventional dosing concentrations, especially when applied to the working environment of oil-water coexistence, the effective content in the water phase is insufficient, thereby resulting in poor anti-corrosion effect.

[0006] In addition, the prior art also has problems such as low flash point, high volatility, strong odor of organic solvents, and poor control effect of water phase corrosion under the condition of coexistence of oil and water. Therefore, how to improve the dispersibility, compatibility and stability of corrosion inhibitors in pipelines while avoiding the introduction of components with high viscosity is an important problem that urgently needs to be solved in natural gas gathering and transportation. However, there is no effective method in the prior art to quickly and directly disperse oil-soluble corrosion inhibitors in water. Summary of the Invention

[0007] The object of the present invention is to overcome the problems of low anti-corrosion efficiency, poor dispersibility, insufficient safety and stability of oil-based corrosion inhibitors in gas field water in the prior art, and to provide an oil-in-water type nanoemulsion loaded with corrosion inhibitors, its preparation method and application. The nanoemulsion loaded with corrosion inhibitors can improve the water solubility and diffusibility of oil-soluble corrosion inhibitors while ensuring the anti-corrosion effect of the corrosion inhibitors, and at the same time improve the safety and stability of the corrosion inhibitor product itself.

[0008] To achieve the above object, in the first aspect of the present invention, an oil-in-water type nanoemulsion loaded with corrosion inhibitors is provided. The nanoemulsion loaded with corrosion inhibitors includes a main corrosion inhibitor, a surfactant, a solvent oil and water; wherein, the main corrosion inhibitor is an oil-soluble corrosion inhibitor.

[0009] Preferably, the particle size of the nanoemulsion loaded with corrosion inhibitors is 20 - 500 nm, preferably 20 - 100 nm.

[0010] In the second aspect of the present invention, a preparation method of the above-mentioned oil-in-water type nanoemulsion loaded with corrosion inhibitors is provided, including the following steps:

[0011] (1) Provide a mixed solution containing a main corrosion inhibitor, a surfactant and a solvent oil;

[0012] (2) Under the condition of stirring, add water to the mixed solution for emulsification to obtain the nanoemulsion loaded with corrosion inhibitors;

[0013] Wherein, the main corrosion inhibitor is an oil-soluble corrosion inhibitor.

[0014] In the third aspect of the present invention, an oil-in-water type nanoemulsion loaded with corrosion inhibitors prepared by the above-mentioned preparation method is provided.

[0015] In the fourth aspect of the present invention, the application of the oil-in-water type nanoemulsion loaded with corrosion inhibitors described in the first aspect and the third aspect in the gathering and transportation of petroleum and natural gas is provided.

[0016] Through the above technical solution, the present invention aims at the disadvantages of poor water solubility and poor diffusion efficiency in the aqueous phase of oil-soluble corrosion inhibitors. By loading the corrosion inhibitor nanoemulsion, the main corrosion inhibitor is encapsulated by the nanoemulsion to improve its water solubility, greatly increase the effective content of the corrosion inhibitor in the aqueous phase in the oil-water coexistence environment, improve the corrosion inhibition performance, and has significant advantages in the corrosion control of metal materials under the oil-water distribution conditions. At the same time, the flash point of the corrosion inhibitor-loaded nanoemulsion provided by the present invention is greatly increased compared with the flash point of the original corrosion inhibitor, improving the safety and stability of the corrosion inhibitor during use.

[0017] The present invention uses the low-energy method to prepare the corrosion inhibitor-loaded nanoemulsion, with flexible reactions, simple and controllable reaction conditions, and low costs. Brief Description of the Drawings

[0018] Figure 1 is the appearance diagram of the corrosion inhibitor-loaded nanoemulsion diluted by different multiples in simulated gas field water;

[0019] Figure 2 is the comparison of the dispersion states of the corrosion inhibitor DS1 in Comparative Example 1 and the corrosion inhibitor-loaded nanoemulsion S1 in Example 1 in water. Detailed Embodiments

[0020] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0021] The first aspect of the present invention provides an oil-in-water type corrosion inhibitor-loaded nanoemulsion, and the corrosion inhibitor-loaded nanoemulsion includes a main corrosion inhibitor, a surfactant, a solvent oil, and water; wherein, the main corrosion inhibitor is an oil-soluble corrosion inhibitor.

[0022] Oil-soluble corrosion inhibitors have a relatively large solubility in the oil phase, and their hydrophilic-lipophilic balance value (HLB) is generally 1-7, making it difficult to disperse uniformly in gas field water. An emulsion is a dispersion system formed by dispersing one liquid in the form of liquid droplets in another immiscible liquid, which can be divided into two types: oil-in-water (O / W) and water-in-oil (W / O). According to the present invention, in the nanoemulsion loaded with the corrosion inhibitor, the emulsion droplet structure is such that the oil droplets of the mixture of the main corrosion inhibitor and the solvent oil are the core (dispersion phase), the surfactant is the oil-water interfacial film, and water is the continuous phase. The oil-soluble corrosion inhibitor is wrapped in the droplet core to form an O / W type nanoemulsion, thereby achieving a high degree of dispersion of the oil-soluble corrosion inhibitor to improve its water solubility and stability. The nanoemulsion after encapsulation still has excellent corrosion inhibition performance and can be used for corrosion control of metal materials. As Figure 1 shown, the nanoemulsion loaded with the corrosion inhibitor provided by this application can be diluted with water in any proportion, has good dispersibility in water, and is conducive to on-site filling.

[0023] According to a preferred embodiment of the present invention, the emulsion particle size of the nanoemulsion loaded with the corrosion inhibitor is 20-500 nm, preferably 20-100 nm. In the above preferred case, because the droplet size is extremely small, there will be no phenomena such as stratification and floating even after standing at room temperature for several months, and the stability is better.

[0024] According to a preferred embodiment of the present invention, the mass ratio of the main corrosion inhibitor, surfactant and solvent oil is (0-0.2):(0.2-1):1, preferably (0.08-0.15):(0.3-0.5):1. Adopting the above preferred embodiment is conducive to the stability of the final product.

[0025] According to a preferred embodiment of the present invention, the mass ratio of the solvent oil to water is not higher than 0.5. Preferably, the mass ratio of the solvent oil to water is 0.25-0.45. In the above preferred case, it helps the nanoemulsion of the corrosion inhibitor to maintain a high kinetic stability.

[0026] In the present invention, the selection range of the main corrosion inhibitor is relatively wide and can be selected from any commonly used oil-soluble corrosion inhibitor according to actual needs. According to a preferred embodiment of the present invention, the main corrosion inhibitor is selected from at least one of polyamine compounds, pyridine compounds, imidazoline compounds, quinoline compounds and rosin derivatives; further preferably, the main corrosion inhibitor is an imidazoline compound and / or a rosin derivative; more preferably, it is the sulfur-containing oleic acid imidazoline described in Example 1 of ZL200610073121.4. In the above preferred case, it is beneficial to improve the corrosion inhibition effect.

[0027] According to a preferred embodiment of the present invention, the solvent oil is a polar and / or non-polar oil substance, preferably a hydrocarbon mineral oil and / or an ester vegetable oil, and further preferably at least one of gas oil, paraffin oil, diesel oil, peanut oil, rapeseed oil, isopropyl myristate, decane, and octane.

[0028] According to the present invention, there is no special limitation on the specific selection of the surfactant, as long as it can reduce the surface tension of the liquid phase. Preferably, the surfactant is a non-ionic surfactant containing a polyoxyethylene group; further preferably, it is at least one of the alkylphenol polyoxyethylene ether series (such as nonylphenol polyoxyethylene (9.7) ether), CE series (such as C12E4, C12E10), Span (such as Span80), and Tween (such as Tween80); more preferably, it is Tween80 and / or Span80.

[0029] According to a preferred embodiment of the present invention, the surfactant is a mixture of Tween80 and Span80, wherein the mass ratio of Tween80 to Span80 is 1.5 - 2.5:1; preferably 1.8 - 2.2:1.

[0030] The second aspect of the present invention provides a method for preparing the above oil-in-water type nanoemulsion loaded with a corrosion inhibitor, comprising the following steps:

[0031] (1) Provide a mixed solution containing a main corrosion inhibitor, a surfactant, and a solvent oil;

[0032] (2) Under stirring conditions, add water to the mixed solution to carry out an emulsification reaction to obtain the nanoemulsion loaded with the corrosion inhibitor;

[0033] Wherein, the main corrosion inhibitor is an oil-soluble corrosion inhibitor.

[0034] In the present invention, a low-energy emulsification method is used to prepare the nanoemulsion loaded with the corrosion inhibitor, and emulsification is achieved through the energy of the system itself. The operation is simple and industrial production can be realized. The nanoemulsion loaded with the corrosion inhibitor obtained by the above method is more uniform. The present invention uses the low-energy method to prepare the nanoemulsion loaded with the corrosion inhibitor, which can improve the safety, stability of the corrosion inhibitor product itself while ensuring the anti-corrosion effect of the corrosion inhibitor, and at the same time can improve its water solubility and diffusibility.

[0035] In the present invention, the types of selection of the main corrosion inhibitor, the surfactant, and the solvent oil are the same as the selection scope and dosage in the above nanoemulsion loaded with the corrosion inhibitor, and will not be elaborated here.

[0036] According to a preferred embodiment of the present invention, the manner of providing the mixed solution includes: first, uniformly mixing the main corrosion inhibitor and the solvent oil, and then adding the surfactant. Adopting the above preferred embodiment is beneficial to the full mixing of the materials.

[0037] According to a preferred embodiment of the present invention, in step (2), water is added to the mixed solution by means of dropping; adopting the above preferred embodiment can better control the addition rate of water. Preferably, relative to 100 mL of the mixed solution, the dropping rate is not higher than 5 mL / min, and more preferably 0.5 - 2 mL / min. At the above preferred dropping rate, it is beneficial to experience key phase states such as bicontinuous phase / liquid crystal phase during the emulsification process, and ultimately beneficial to the formation of nanoemulsions with smaller particle sizes.

[0038] According to a preferred embodiment of the present invention, the temperature of the emulsification reaction is 30 - 60 °C, preferably 40 - 70 °C. In the present invention, before step (2), the mixed solution and water are preheated to the emulsification reaction temperature respectively, and then emulsification is carried out. Preferably, the preheating time is 5 - 15 min.

[0039] According to a preferred embodiment of the present invention, the stirring rate is 50 - 600 rpm, and more preferably 50 - 200 rpm. Those skilled in the art can understand that higher stirring speeds can be adopted, but from the perspective of energy consumption, at the above preferred stirring rate, uniform mixing of the materials can be achieved with lower energy consumption.

[0040] The third aspect of the present invention provides an oil-in-water type nanoemulsion loaded with a corrosion inhibitor prepared by the above preparation method.

[0041] The fourth aspect of the present invention provides the application of the above oil-in-water type nanoemulsion loaded with a corrosion inhibitor in the gathering and transportation of oil and gas.

[0042] In a typical surface gathering and transportation system of a sulfur-containing natural gas field, the nanoemulsion loaded with a corrosion inhibitor is continuously injected through an injection pump at the natural gas wellhead to control the corrosion of metal materials such as pipelines and equipment.

[0043] According to a preferred embodiment of the present invention, the injection amount of the nanoemulsion loaded with a corrosion inhibitor is 0.17 - 0.66 L per ten thousand cubic meters of gas volume.

[0044] According to the present invention, the nanoemulsion loaded with corrosion inhibitor prepared by the above preparation method is light blue to milky white. When in use, the aqueous agent can be directly added to the required water medium or diluted with water in any proportion and then used. The nanoemulsion loaded with corrosion inhibitor can be rapidly dispersed in water. When in the oil and gas gathering and transportation pipeline, due to its excellent aqueous phase dispersibility, it can increase the effective content of the corrosion inhibitor in the aqueous phase at the conventional dosing concentration, and improve the anti-corrosion effect in the oil and gas gathering and transportation pipeline.

[0045] The present invention will be described in detail below through examples.

[0046] In the following examples, the particle size of the emulsion was measured by a laser particle size analyzer (DLS);

[0047] The corrosion rate was measured by the corrosion coupon method;

[0048] The rosin imidazoline quaternary ammonium salt compound in Example 1 was the rosin imidazoline quaternary ammonium salt compound obtained in Example 1 of Patent ZL201710262166.4;

[0049] CT2-19 was the sulfur-containing imidazoline obtained in Example 1 of Patent ZL200610073121.4.

[0050] Example 1

[0051] Take 0.8 g of oil-soluble corrosion inhibitor (rosin imidazoline quaternary ammonium salt compound) and 10 g of liquid paraffin oil, and stir and mix evenly. To the above mixture, add 5 g of mixed surfactant (Tween80:Span80 = 1.5), and continue to stir evenly to obtain a mixed oil phase. Preheat the mixed oil phase and 24 g of deionized water to 40 °C in a constant temperature water bath, keep it for 10 min, and then gradually add the deionized water to the mixed oil phase while maintaining stirring at 50 rpm, with a dropping rate of 1 mL / min, and naturally cool to room temperature to prepare a nanoemulsion S1 loaded with corrosion inhibitor. The test results are shown in Table 1, and the dispersion effect in water at a dosing amount of 3000 ppm is as Figure 2 shown, and the dispersibility is good.

[0052] Comparative Example 1

[0053] Mix the oil-soluble corrosion inhibitor and liquid paraffin oil described in Example 1 in a mass ratio of 1:4 and use it directly, denoted as DS1. The test results are shown in Table 1, and the dispersion effect in water at a dosing amount of 3000 ppm is as Figure 2 shown, and the corrosion inhibitor floats on the water surface or suspends in water in the form of large oil beads.

[0054] Example 2

[0055] Take 1.5 g of oil-soluble corrosion inhibitor (CT2-19) and 10 g of solvent oil (diesel), and stir and mix them evenly. Add 3 g of mixed surfactant (Tween80:Span80 = 2.2) to the above mixture, and continue to stir evenly to obtain a mixed oil phase. Preheat the mixed oil phase and 40 g of deionized water to 70 °C in a constant temperature water bath, keep it for 10 min, then gradually add the deionized water to the mixed oil phase under the condition of stirring at 200 rpm, with a dropping rate of 0.5 mL / min, and naturally cool to room temperature to prepare nanoemulsion S2 loaded with corrosion inhibitor. The test results are shown in Table 1.

[0056] Example 3

[0057] Take 1.0 g of oil-soluble corrosion inhibitor (CT2-19) and 10 g of solvent oil (gas oil), and stir and mix them evenly. Add 4 g of mixed surfactant (Tween80:Span80 = 2.0) to the above mixture, and continue to stir evenly to obtain a mixed oil phase. Preheat the mixed oil phase and 40 g of deionized water to 55 °C in a constant temperature water bath, keep it for 10 min, then gradually add the deionized water to the mixed oil phase under the condition of stirring at 300 rpm, with a dropping rate of 1 mL / min, and naturally cool to room temperature to prepare nanoemulsion S3 loaded with corrosion inhibitor. The test results are shown in Table 1.

[0058] Example 4

[0059] According to the method of Example 1, the difference is that the addition amount of oil-soluble corrosion inhibitor is 2 g, and nanoemulsion S4 loaded with corrosion inhibitor is prepared. The test results are shown in Table 1.

[0060] Example 5

[0061] According to the method of Example 1, the difference is that the addition amount of deionized water is 10 g, and nanoemulsion S5 loaded with corrosion inhibitor is prepared. The test results are shown in Table 1.

[0062] Example 6

[0063] According to the method of Example 1, the difference is that the addition amount of deionized water is 40 g, and nanoemulsion S6 loaded with corrosion inhibitor is prepared. The test results are shown in Table 1.

[0064] Example 7

[0065] According to the method of Example 1, the difference is that the preheating temperature is 30 °C and the dropping rate of water is 0.5 mL / min, and nanoemulsion S7 loaded with corrosion inhibitor is prepared. The test results are shown in Table 1.

[0066] Example 8

[0067] According to the method of Example 1, except that the preheating temperature is 60 °C, the nanoemulsion S8 loaded with the corrosion inhibitor is prepared, and the test results are shown in Table 1.

[0068] Example 9

[0069] According to the method of Example 1, except that the dropping rate of deionized water is 5 mL / min, the nanoemulsion S9 loaded with the corrosion inhibitor is prepared, and the test results are shown in Table 1.

[0070] Comparative Example 2

[0071] According to the method of Example 1, except that a water-soluble corrosion inhibitor (oleic acid amide compound) is directly used, denoted as DS2, and the test results are shown in Table 1.

[0072] Table 1

[0073]

[0074] Test Examples 1-9 and Comparative Test Examples 1-2:

[0075] The effective contents in water of S1-S9 and DS1-DS2 were respectively compared. The test conditions included:

[0076] A 5 wt% sodium chloride aqueous solution and heptane with a volume ratio of 1:1 were prepared. The dosing amounts of the nanoemulsions S1-S9 loaded with the corrosion inhibitor were based on the total mass of the nanoemulsions loaded with the corrosion inhibitor, and the dosing amounts of DS1 and DS2 were based on the total mass of the solution. As shown in Table 2, after standing and separating for 2 hours at 40 °C for oil-water distribution, the residual concentration of the corrosion inhibitor in the aqueous phase was measured by ultraviolet spectrophotometry, and the results are shown in Table 2.

[0077] Table 2

[0078]

[0079]

[0080] The corrosion inhibition effects of S1-S9 and DS1-DS2 in the coexistence of oil and water were compared:

[0081] The experimental method was carried out with reference to the standard JB / T7901-2001 Metallic materials - Laboratory immersion corrosion test for uniform corrosion. The test conditions included: the temperature was 80 °C, a 5.0 wt% NaCl aqueous solution (deaerated), H2S: 1000 ppm, CO2: 240 ppm, and an oxygen-free environment. The experimental metal material was L360, which is a commonly used material for oil and gas field surface gathering and transportation pipelines. The test period was 72 hours.

[0082] The dosing amounts of the nanoemulsions S1 - S9 of the load corrosion inhibitor are based on the total mass of the nanoemulsion of the load corrosion inhibitor, and the dosing amounts of DS1 and DS2 are based on the total mass of the solution. On this basis, the oil - water distribution is increased. That is, before the test, first refer to the scheme of comparing the effective content in water, conduct the oil - water distribution, and then take the lower - layer water for corrosion evaluation. The corrosion rate is calculated by calculating the weight loss before and after the test. The blank sample is used as a control group without adding a corrosion inhibitor. The test data are shown in Table 3.

[0083] Table 3

[0084]

[0085] The nanoemulsion S1 of the load corrosion inhibitor in Example 1 was used for actual pipeline applications. The basic situation of a pipeline in the Sichuan - Chongqing region and the continuous dosing amount of the corrosion inhibitor are shown in Table 4. Multiple means such as ultrasonic thickness measurement, corrosion coupon, and electrochemical probe were used for corrosion monitoring. After 3 months of monitoring, the average corrosion rate of the pipeline was calculated to be about 0.019 mm / a, achieving a good control effect.

[0086] Table 4

[0087]

[0088]

[0089] It can be seen from the results in Table 1 that Examples 1 - 9 of the oil - in - water type load corrosion inhibitor nanoemulsion of the present invention, compared with Comparative Example 1, help to improve the dispersion of the oil - based corrosion inhibitor in the aqueous phase, and significantly reduce the use of solvent oil, which is beneficial for post - treatment. At the same time, the flash point of the oil - in - water type load corrosion inhibitor nanoemulsion provided by the present invention is higher than 100 °C, which can significantly improve the safety factor during use. It can be seen from Examples 5 and 7 that when the emulsion particle size of the nanoemulsion is too large, the stability is poor.

[0090] It can be seen from the results in Table 2 that compared with the conventional oil - soluble corrosion inhibitor used in Comparative Example 1, the effective content in the aqueous phase of the load corrosion inhibitor nanoemulsion provided by the present invention is significantly increased at the conventional dosing concentration. Combining the data in Table 3, it can be further confirmed that the load corrosion inhibitor nanoemulsion provided by the present invention has a more excellent anti - corrosion effect under the condition of oil - water distribution. Further, in the actual natural gas gathering pipeline, the load corrosion inhibitor nanoemulsion provided by the present invention also has a good corrosion control effect.

[0091] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including the combination of each technical feature in any other suitable manner. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. An oil-in-water nanoemulsion loaded with a corrosion inhibitor, characterized in that, The nanoemulsion loaded with a corrosion inhibitor comprises a main corrosion inhibitor, a surfactant, a solvent oil and water; Among them, the main corrosion inhibitor is an oil-soluble corrosion inhibitor; The main corrosion inhibitor is selected from at least one of polyamine compounds, pyridine compounds, imidazoline compounds, quinoline compounds and rosin derivatives; The surfactant is a non-ionic surfactant containing a polyoxyethylene group; The solvent oil is a polar and / or non-polar oil substance; The mass ratio of the main corrosion inhibitor, the surfactant and the solvent oil is (0.08 - 0.15):(0.3 - 0.5):1; The mass ratio of the solvent oil and water is 0.25 - 0.45:

1.

2. The nanoemulsion of the load corrosion inhibitor according to claim 1, wherein, The emulsion particle size of the nanoemulsion loaded with a corrosion inhibitor is 20 - 500 nm.

3. The nanoemulsion of the load inhibitor according to claim 2, wherein, The emulsion particle size of the nanoemulsion loaded with a corrosion inhibitor is 20 - 100 nm.

4. The nanoemulsion for loading a corrosion inhibitor according to any one of claims 1-3, wherein, The main corrosion inhibitor is an imidazoline compound; And / or, the solvent oil is a hydrocarbon mineral oil and / or an ester vegetable oil; And / or, the surfactant is Tween80 and / or Span80.

5. The nanoemulsion of the load corrosion inhibitor according to claim 4, wherein, The solvent oil is selected from at least one of gas-made oil, paraffin oil, diesel oil, peanut oil, rapeseed oil, isopropyl myristate, decane and octane; And / or, the surfactant is a mixture of Tween80 and Span80, wherein the mass ratio of Tween80 and Span80 is 1.5 - 2.5:

1.

6. A method for preparing an oil-in-water nanoemulsion loaded with a corrosion inhibitor according to any one of claims 1-5, characterized in that, Comprises the following steps: (1) Provide a mixed solution containing a main corrosion inhibitor, a surfactant and a solvent oil; (2) Under stirring conditions, add water to the mixed solution to carry out an emulsification reaction to obtain the nanoemulsion loaded with a corrosion inhibitor; Among them, the main corrosion inhibitor is an oil-soluble corrosion inhibitor.

7. The preparation method according to claim 6, wherein, In step (2), water is added to the mixed solution by dropwise addition.

8. The preparation method according to claim 7, wherein Relative to 100 mL of the mixed solution, the dropping rate is not higher than 5 mL / min.

9. The preparation method according to claim 8, wherein Relative to 100 mL of the mixed solution, the dropping rate is 0.5 - 2 mL / min.

10. The preparation method according to claim 6, wherein, The temperature of the emulsification reaction is 30 - 80 °C.

11. The preparation method according to claim 10, wherein, The temperature of the emulsification reaction is 40 - 70 °C.

12. The preparation method according to any one of claims 6-11, wherein, The stirring rate is 50 - 600 rpm.

13. The preparation method according to claim 12, wherein, The stirring rate is 50 - 200 rpm.

14. An oil-in-water nanoemulsion loaded with a corrosion inhibitor prepared by the preparation method according to any one of claims 6 - 13.

15. Application of the oil-in-water nanoemulsion loaded with a corrosion inhibitor according to any one of claims 1 - 5 and 14 in oil and gas gathering and transportation.

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