Condensate oil nano demulsifier as well as preparation method and application thereof

Abstract

The invention provides a condensate oil nano demulsifier as well as a preparation method and application thereof, the preparation method comprises the following steps: S1, adding 1, 3-propane diamine and methyl acrylate into an ethanol solution containing sodium ethoxide, and reacting to obtain a prepolymer; s2, adding nano silicon dioxide and a coupling agent into an ethanol solution, adjusting the pH value, and reacting to obtain a modifier; and S3, adding the obtained prepolymer and the modifier into an ethanol solution containing sodium ethoxide, and reacting to obtain the condensate oil nano demulsifier. The condensate oil nano demulsifier is a space network structure polymer with nano silicon dioxide as a core connection point, and the size of a repeating unit structure of the condensate oil nano demulsifier is 100-200 nm. The condensate oil nano demulsifier provided by the invention is excellent in performance, has a good demulsification effect on a condensate oil emulsion, and can significantly improve the oil-water separation efficiency of the condensate oil emulsion.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas field development and oil and gas field applied chemistry, and in particular to a condensate oil nano-emulsifier and a preparation method and application thereof. Background Art

[0002] In the process of gas well condensate production, various measures will inject a large amount of surfactant liquid into the gas well, so that the well fluid and condensate form a complex emulsion system, which makes it very difficult to demulsify the condensate emulsion. This will not only affect the yield and quality of condensate, but also bring severe challenges to the normal operation of the purification plant and the production of the gas field.

[0003] Most of the existing demulsifier technologies are based on conventional crude oil demulsification. For example, Zhang Lifeng et al. disclosed a hyperbranched polyglycidyl methacrylate as a demulsifier for O / W emulsions (Reference: Zhang Lifeng, Zhan Ningning, Qin Lijuan, et al. Hyperbranched polyglycidyl methacrylate as a demulsifier for O / W emulsions [J]. Chemical Industry Progress, 2021, 40(06): 3434-3443.), with an oil removal rate of 90% at a concentration of 2000 mg / L. For example, Xu Hui et al. used methyl acrylate and 1,3-propylenediamine as raw materials to synthesize a hyperbranched polymer reverse demulsifier (reference: Xu Hui, Wei Qing, Zhang Lifeng, et al. Synthesis and performance of a hyperbranched polymer reverse demulsifier [J]. Fine Petrochemicals, 2019, 36(03): 46-49.), and the oil removal rate reached 91% when the addition amount was 40 mg / L, the demulsification temperature was 60 ° C, and the sedimentation time was 30 min. The above research has a good effect on general crude oil demulsification, but its applicability to condensate oil remains to be studied.

[0004] Different from crude oil demulsification, condensate oil emulsion is a special emulsion layer demulsification rarely seen in oil fields. Its causes are complex and varied. In addition, condensate oil generally has a small molecular weight and is more easily emulsified to form an emulsion. The selection of demulsifier becomes a difficult point.

[0005] The Chinese patent with application number "CN201310552699.8" and titled "A condensate oil emulsion demulsifier and its application" discloses a condensate oil emulsion demulsifier and its application. The demulsifier is composed of a benzenesulfonate anionic surfactant, a polyether nonionic surfactant, a low molecular alcohol and water. Based on 100% by mass, the benzenesulfonate anionic surfactant is 5-10%, the polyether nonionic surfactant is 5-20%, the low molecular alcohol is 10-30%, and the balance is water. However, the patent focuses on the use of acidic gas fields producing condensate oil, and a large amount of sulfonate and dispersant are added to the formula, and its acid and alkali resistance and salt resistance are poor.

[0006] The Chinese patent with application number "CN201410200571.X" and titled "Preparation method and application of a condensate oil demulsifier" discloses a preparation method and application of a condensate oil demulsifier, adding 5 to 60 parts by mass of solvent to a reactor or a mixer; turning on the agitator, adding 2 to 25 parts of sulfonate, 5 to 20 parts of polyethylene polyamine polyoxyethylene polyoxypropylene polyether, and 1 to 25 parts of polyoxyethylene polyoxypropylene octadecyl alcohol ether in sequence, and reacting for 1 to 30 minutes; slowly adding 1 to 15 parts of alkyl phenolic resin block polyether, 5 to 10 parts of silicon-containing demulsifier, and 5 to 10 parts of dispersant, and reacting for 10 to 60 minutes. However, in addition to a large amount of sulfonate, the patent formula also adds an organosilicon surfactant, which will increase the silicon content of the condensate oil and reduce the quality of the condensate oil. In addition, the formula components are varied, the ingredients are complex, and the controllability is poor.

[0007] Therefore, it is of great significance to prepare a condensate demulsifier with excellent performance, good demulsification effect and the ability to significantly improve the oil-water separation efficiency of the condensate oil emulsion under mild preparation conditions, easy-to-control reaction conditions and safe reaction process. Summary of the invention

[0008] In view of the deficiencies in the prior art, the object of the present invention is to solve one or more problems in the above-mentioned prior art. For example, one of the objects of the present invention is to provide a method for preparing a condensate demulsifier with mild preparation conditions, easy control of reaction conditions and safe reaction process. For another example, another object of the present invention is to provide a condensate demulsifier with stable properties, excellent performance, good demulsification effect and the ability to significantly improve the oil-water separation efficiency of the condensate emulsion.

[0009] In order to achieve the above-mentioned purpose, the present invention provides a method for preparing a condensate oil nano-emulsifier, which may include the following steps: S1, adding 1,3-propylenediamine and methyl acrylate to an ethanol solution containing sodium ethoxide, reacting to obtain a prepolymer; S2, adding nano-silica and a coupling agent to the ethanol solution, adjusting the pH, reacting to obtain a modified body; S3, adding the obtained prepolymer and the modified body to an ethanol solution containing sodium ethoxide, reacting to obtain a condensate oil nano-emulsifier.

[0010] According to one or more exemplary embodiments of an aspect of the present invention, in step S1, the ratio of the sodium ethoxide to the ethanol may be 1:(0.1-2) g / L, the ratio of the 1,3-propylenediamine to the ethanol may be 1:(0.1-2) mol / L, and the molar ratio of the 1,3-propylenediamine to the methyl acrylate may be 1:(1-8).

[0011] According to one or more exemplary embodiments of an aspect of the present invention, in step S2, the ratio of the silica to the ethanol may be 1:(0.01-0.1) g / L, and the mass ratio of the nano-silica to the coupling agent may be 1:(0.05-0.2).

[0012] According to one or more exemplary embodiments of an aspect of the present invention, in step S3, the ratio of the sodium ethoxide to the ethanol may be 1:(0.1-2) g / L.

[0013] According to one or more exemplary embodiments of an aspect of the present invention, in step S1, the reaction temperature may be 50-90°C, and the reaction time may be 4-12 hours; in step S2, the reaction temperature may be 40-80°C, and the reaction time may be 1-4 hours; in step S3, the reaction temperature may be 60-120°C, and the reaction time may be 4-24 hours.

[0014] According to one or more exemplary embodiments of an aspect of the present invention, the coupling agent may include at least one of vinyl triethoxy silane, vinyl trimethoxy silane, methacryloxypropyl trimethoxy silane, 3-aminopropyl trimethoxy silane, 3-aminopropyl triethoxy silane or N-2-aminoethyl-3-aminopropyl trimethoxy silane; the nano-silica is hydrophilic nano-silica, and its particle size may be 5 to 20 nm.

[0015] According to one or more exemplary embodiments of an aspect of the present invention, the reagent used to adjust the pH may include hydrochloric acid; and the pH of the solution after the pH adjustment may be 1-7.

[0016] Another aspect of the present invention provides a condensate oil nano-emulsifier, which can be prepared by the above-mentioned preparation method of the condensate oil nano-emulsifier.

[0017] According to one or more exemplary embodiments of another aspect of the present invention, the condensate oil nano-emulsifier is a spatial network structure polymer with nano-silicon dioxide as the core connection point, and the size of the repeating unit structure can be 100-200 nm.

[0018] In another aspect, the present invention provides an application of a condensate oil nano-emulsifier, which may include application in a condensate oil emulsion demulsification process.

[0019] Compared with the prior art, the beneficial effects of the present invention include at least one of the following:

[0020] (1) The preparation method of the condensate oil nano-emulsifier provided by the present invention starts from a polyamide demulsifier, combines nanomaterials, and adopts a step-by-step polymerization method to obtain a spatial network nano-polymer material with multiple cross-links. In the process of demulsifying condensate oil in a gas field, the oil-water separation efficiency can be effectively improved.

[0021] (2) The raw materials used in the preparation method of the condensate oil nano-emulsifier provided by the present invention have been industrially produced, the raw materials are easy to obtain, the reaction process is simple, the preparation can be completed under general chemical conditions, the preparation conditions are mild, the reaction conditions are easy to control, and the reaction process is safe.

[0022] (3) The condensate oil nano-emulsifier provided by the present invention has stable properties, the nano-polymer repeating units in the demulsifier reach the nano level, and can be stably stored for a long time at room temperature and pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and other objects and / or features of the present invention will become more apparent through the following description in conjunction with the accompanying drawings, in which:

[0024] Figure 1 The transmission electron microscope image of the condensate oil nano-emulsifier prepared in Example 4 of the present invention is shown;

[0025] Figure 2a The schematic diagram of the demulsification experiment at zero time when 0.1-2% of the nano demulsifier prepared in Example 4 is added in the present invention is shown;

[0026] Figure 2b The schematic diagram of the demulsification experiment is shown after adding 0.1-2% of the nano demulsifier prepared in Example 4 and letting it stand for 5 hours. DETAILED DESCRIPTION

[0027] Hereinafter, a condensate oil nano-emulsifier and a preparation method and application thereof of the present invention will be described in detail in conjunction with the accompanying drawings and exemplary embodiments.

[0028] Exemplary Embodiment 1

[0029] This exemplary embodiment provides a method for preparing a condensate oil nano-emulsifier.

[0030] The preparation method of condensate oil nano-emulsifier mainly comprises the following steps:

[0031] S1. 1,3-propylenediamine and methyl acrylate are reacted in the presence of ethanol and sodium ethoxide to obtain a prepolymer.

[0032] S2. Dispersing nano-silica and a coupling agent in ethanol, adjusting the pH to react and obtaining a modified body, wherein the particle size of the nano-silica is 5 to 20 nm, and the nano-silica is hydrophilic.

[0033] S3. Add the prepolymer to the modified body, add an ethanol solution of sodium ethoxide to disperse and further react, and the obtained milky yellow colloid is the condensate oil nano-emulsifier.

[0034] In this exemplary embodiment, in step S1, the ratio of sodium ethoxide to ethanol may be 1: (0.1-2) g / L, for example, 1: 0.3, 1: 0.6, 1: 1.1, 1: 1.4 or 1: 1.8. Here, the ratio is to control the content of sodium ethoxide. If there is too little sodium ethoxide, the reaction initiation efficiency is low, and if there is too much sodium ethoxide, the alkalinity of the system after the reaction is too high. Preferably, the ratio of sodium ethoxide to ethanol may be 1: (0.5-1) g / L, for example, 1: 0.6 or 1: 0.9. The ratio of 1,3-propylenediamine to ethanol may be 1: (0.1-2) mol / L, for example, 1: 0.3, 1: 0.6, 1: 1.1, 1: 1.4 or 1: 1.8. Here, the ratio is to control the content of 1,3-propylenediamine, thereby controlling the concentration of the subsequent product in the solvent system. If there is too little 1,3-propylenediamine, the product needs to be increased in amount during application. If there is too much, the dispersibility of the product in the solvent decreases, which has a greater impact on the stability of the product. Preferably, the ratio of 1,3-propylenediamine to ethanol can be 1: (0.1-0.5) mol / L, for example, 1: 0.2 or 1: 0.4. The molar ratio of 1,3-propylenediamine to methyl acrylate can be 1: (1-8), for example, 1: 2, 1: 4 or 1: 7. Here, the ratio is to control the amount of methyl acrylate. If there is too little methyl acrylate, there are more unreacted functional groups of 1,3-propylenediamine, which affects the branching degree of the product, thereby reducing the performance of the product; if there is too much methyl acrylate, methyl acrylate will self-polymerize, and the self-polymer does not have the performance of the product, and is weakly dispersed in the system, and is prone to precipitation, affecting the performance and stability of the product. Preferably, the molar ratio of 1,3-propylenediamine and methyl acrylate may be 1:(2-4), for example, 1:2.5, 1:3 or 1:3.5. The reaction temperature may be 50-90°C, for example, 55°C, 70°C, 75°C or 85°C. Here, in order to control the reaction temperature, if the temperature is too low, the reaction initiation efficiency is low and the product performance is poor. If the temperature is too high, the reaction may undergo explosive polymerization and the heating equipment needs to be replaced, thereby increasing the risk and cost of preparation. The reaction time may be 4-12h, for example, 5h, 7h, 9h or 11h. Here, in order to control the reaction time, if the reaction time is too short, the reaction is insufficient, and if it is too long, the reaction has reached equilibrium, which will increase energy consumption and preparation cycle, thereby increasing production costs.

[0035] In this exemplary embodiment, in step S2, the ratio of nano-silicon dioxide to ethanol may be 1: (0.01-0.1) g / L, for example, 1: 0.02, 1: 0.04, 1: 0.07 or 1: 0.09. Here, the ratio is to control the content of nano-silicon dioxide, thereby controlling the concentration of the subsequent product in the solvent system. If there is too little nano-silicon dioxide, the product needs to be increased in amount in the application, and if there is too much nano-silicon dioxide, the dispersibility of the product in the solvent decreases, which has a greater impact on the stability of the product. Preferably, the ratio of nano-silicon dioxide to ethanol may be 1: 0.05 g / L. The mass ratio of nano-silicon dioxide to coupling agent may be 1: (0.05-0.2), for example, 1: 0.07, 1: 0.1, 1: 0.13, 1: 0.15 or 1: 0.18. Here, the ratio is to control the content of the coupling agent. If the coupling agent is too little, the nano-silica cannot react completely, resulting in losses. If the coupling agent is too much, in addition to increasing the cost, it will also affect the performance and stability of the product. Preferably, the mass ratio of nano-silica to the coupling agent can be 1:0.1. The reaction temperature can be 40 to 80°C, for example, 45°C, 55°C, 65°C or 75°C. Here, in order to control the reaction temperature, if the temperature is too low, the reaction initiation efficiency is low, the product performance is poor, and if the temperature is too high, the reaction may be violently polymerized, and the heating equipment needs to be replaced, thereby increasing the risk and cost of preparation. The reaction time can be 1 to 4h, for example, 1.5h, 2.5h, 3h or 3.5h. Here, in order to control the reaction time, if the reaction time is too little, the reaction is not sufficient, and if it is too much, the reaction has reached equilibrium, which will increase energy consumption and preparation cycle, thereby increasing production costs. Preferably, the reaction temperature can be 60°C and the reaction time can be 2h. The reagent used to adjust the pH may include hydrochloric acid, and the pH of the solution after adjusting the pH may be 1 to 7. Preferably, the pH of the solution after pH adjustment may be 4.

[0036] In this exemplary embodiment, in step S2, the coupling agent may include at least one of vinyl triethoxysilane (A151), vinyl trimethoxysilane (A171), methacryloxypropyl trimethoxysilane (KH-570), 3-aminopropyl trimethoxysilane (KH-540), 3-aminopropyl triethoxysilane (KH-550) or N-2-aminoethyl-3-aminopropyl trimethoxysilane (KH-792). Here, in order to allow the modified body modified with the coupling agent to react better with the prepolymer prepared in step S1, the selected coupling agents all have the characteristics of amino groups and double bonds.

[0037] Further, in step S2, the coupling agent may be methacryloxypropyltrimethoxysilane (KH-570) or N-2-aminoethyl-3-aminopropyltrimethoxysilane (KH-792).

[0038] In this exemplary embodiment, in step S3, the ratio of sodium ethoxide to ethanol may be 1: (0.1-2) g / L, for example, 1: 0.2, 1: 0.5, 1: 0.8, 1: 1.3, 1: 1.5 or 1: 1.8. Here, the ratio is to control the content of sodium ethoxide. If there is too little sodium ethoxide, the reaction initiation efficiency is low, and if there is too much sodium ethoxide, the alkalinity of the system after the reaction is too high. Preferably, the ratio of sodium ethoxide to ethanol may be 1: (0.5-1) g / L, for example, 1: 0.6, 1: 0.7 or 1: 0.9. The reaction temperature may be 60-120°C, for example, 65°C, 70°C, 85°C, 90°C, 95°C, 110°C or 115°C. Here, in order to control the reaction temperature, if the temperature is too low, the reaction initiation efficiency is low, the product performance is poor, and if the temperature is too high, the reaction may be violently polymerized, and the heating equipment needs to be replaced, thereby increasing the risk and cost of preparation. Preferably, the temperature of the reaction may be 80 to 100 ° C, for example, 85 ° C, 90 ° C or 95 ° C. The reaction time may be 4 to 24 h, for example, 5 h, 7 h, 8.5 h, 9 h, 9.7 h, 10.5 h, 11 h, 15 h, 18 h, 21 h or 23 h. Here, in order to control the reaction time, if the reaction time is too little, the reaction is insufficient, and if the reaction time is too much, the reaction has reached equilibrium, which will increase energy consumption and preparation cycle, thereby increasing production costs. Preferably, the reaction time may be 8 to 12 h, for example, 8.5 h, 9.5 h, 10.5 h or 11.5 h.

[0039] Exemplary Embodiment 2

[0040] This exemplary embodiment provides a condensate oil nano-emulsifier.

[0041] The condensate oil nano-emulsifier can be prepared by the preparation method of the condensate oil nano-emulsifier described in the above exemplary embodiment 1.

[0042] In this exemplary embodiment, the condensate oil nano-emulsifier may be a spatial network structure polymer with nano-silicon dioxide as the core connection point, and the size of the repeating unit structure may be 100 to 200 nm, having the characteristics of nano-materials.

[0043] In order to better understand the exemplary implementation 2 of the present invention, it is further described below with reference to specific examples.

[0044] Figure 1 The transmission electron microscope image of the condensate oil nano-emulsifier prepared in Example 4 of the present invention is shown; Figure 2a The schematic diagram of the demulsification experiment at zero time when 0.1-2% of the nano demulsifier prepared in Example 4 is added in the present invention is shown; Figure 2b The schematic diagram of the demulsification experiment is shown after adding 0.1-2% of the nano demulsifier prepared in Example 4 and letting it stand for 5 hours.

[0045] Example 1

[0046] (1) 50 mL of ethanol and 0.1 g of sodium ethoxide were added to a reactor respectively, and after dissolving, 0.1 mol (7.4 g) of 1,3-propylenediamine and 0.2 mol (17.2 g) of methyl acrylate were added, and the mixture was reacted at 80° C. for 8 h to obtain a bright yellow prepolymer;

[0047] (2) 1.0 g of hydrophilic nano-silica and 0.1 g of N-2-aminoethyl-3-aminopropyltrimethoxysilane (KH-792) were dispersed in 50 mL of ethanol, the pH was adjusted to 4 with 1 mol of hydrochloric acid, and the mixture was reacted at 60° C. for 2 h to obtain a modified product in a dispersed state;

[0048] (3) The above prepolymer and 0.1 g of sodium ethoxide were dissolved in 50 mL of ethanol, and added to the dispersed modified body. The temperature was raised to 80° C. and reacted for 12 h. The obtained orange-yellow emulsion was the condensate oil nano-emulsifier.

[0049] Example 2

[0050] The method of Example 1 is followed except that 0.1 g of sodium ethoxide in step (1) is replaced by 0.5 g of sodium ethoxide, the temperature is changed to 60° C., and the other steps are the same as those of Example 1. The obtained orange-yellow emulsion is the condensate oil nano-emulsifier.

[0051] Example 3

[0052] The method of Example 1 is followed, except that the N-2-aminoethyl-3-aminopropyltrimethoxysilane (KH-792) in step (2) is replaced by methacryloxypropyltrimethoxysilane (KH-570), and the other steps are the same as those of Example 1. The obtained orange-yellow emulsion is the condensate oil demulsifier.

[0053] Example 4

[0054] The method of Example 1 is followed, except that 0.2 mol (17.2 g) of methyl acrylate in step (1) is replaced by 0.4 mol (34.4 g) of methyl acrylate, and N-2-aminoethyl-3-aminopropyltrimethoxysilane (KH-792) in step (2) is replaced by methacryloxypropyltrimethoxysilane (KH-570). The other steps are the same as those of Example 1, and the obtained orange-yellow emulsion is the condensate oil demulsifier.

[0055] Example 5

[0056] The method of Example 1 is followed, except that: 0.2 mol (17.2 g) of methyl acrylate in step (1) is replaced by 0.4 mol (34.4 g) of methyl acrylate, N-2-aminoethyl-3-aminopropyltrimethoxysilane (KH-792) in step (2) is replaced by methacryloxypropyltrimethoxysilane (KH-570), and the reaction temperature and time in step (3) are changed to 90° C. and 8 h, respectively. The other steps are the same as in Example 1, and the orange-yellow emulsion obtained is the condensate oil demulsifier.

[0057] Figure 1 This is a transmission electron micrograph of the condensate oil nano-emulsifier prepared in Example 4. It can be seen from the transmission electron micrograph that the prepared nano-emulsifier is a spatial network structure polymer with nano-silicon dioxide as the core connection point, and the size of its repeating unit structure is 100 to 200 nm, indicating that the condensate oil nano-emulsifier prepared by the present invention has the characteristics of nano-materials.

[0058] According to the "Light Crude Oil" implementation standard in the "General Technical Conditions for Crude Oil Demulsifiers" (SY / T5280-2018), a demulsification experiment was carried out, and the dehydration rates of the condensate oil nano-demulsifiers prepared in Examples 1-5 of the present invention on the simulated light crude oil at concentrations of 0.1% to 2.0% were measured respectively. The experimental results are shown in Table 1.

[0059] Table 1 Dehydration rate of condensate oil by different demulsifiers at different concentrations

[0060]

[0061] Among them, the demulsifier in comparative example 1 is a condensate demulsifier SW-70 selected from the Sulige gas field (reference: Wang Tiantian, Li Mingxing, Yu Shuzhen, et al. Screening and evaluation of demulsifiers for condensate produced fluid in typical blocks of Sulige gas field [J]. Daily Chemical Industry, 2020, 50(11): 756-761+770.), the demulsifier in comparative example 2 is prepared by 10% branched dodecylbenzene sulfonate, 20% polyoxypropylene polyoxyethylene glycol ether, 20% ethylene glycol butyl ether and 50% deionized water, and the demulsifier in comparative example 3 is prepared by 35 parts of ethanol, 10 parts of C 6-16 It is prepared from alkylnaphthalenesulfonic acid, 15 parts of AE9901 demulsifier, 3 parts of SP169 demulsifier, 7 parts of BPE2070 demulsifier, 2 parts of AF6231 demulsifier, 8 parts of AF3125 demulsifier, 5 parts of PFA8311 demulsifier, 10 parts of SAP116 demulsifier and dodecyl dimethyl betaine.

[0062] Combined with the data in Table 1, it can be seen that the condensate oil nano-emulsifier prepared by the present invention has reached the index of the light crude oil dehydration rate in the implementation standard (≥90%) within the experimental concentration range. Comparative Example 1, Example 2 increases the amount of catalyst, reduces the temperature of the prepolymer reaction, and the demulsification performance of the prepared product decreases, indicating that the prepolymer preparation reaction is mainly affected by the reaction temperature. Comparative Example 1 and Example 3, changing the type of coupling agent in the modified body preparation reaction, the demulsification performance of the prepared product is slightly improved, indicating that the coupling agent containing hydroxyl functional groups is more conducive to the preparation of the nano-emulsifier of the present invention than the coupling agent containing amino functional groups. Comparative Example 3 and Example 4, increasing the methyl acrylate content in the prepolymer preparation reaction can further enhance the performance of the demulsifier, indicating that the increase in the branching degree of the nano-emulsifier will improve its demulsification performance. Comparative Example 4 and Example 5, trying to increase the reaction temperature of the demulsifier to shorten its reaction time does not significantly improve the performance of the nano-emulsifier. On the one hand, it may be that the temperature rise is not obvious, and on the other hand, it may be that the spatial network structure of the nano-emulsifier does not change significantly.

[0063] Take 100 mL of Sulige gas field condensate emulsion in a centrifuge tube, add 0.1-2% of the nano demulsifier prepared in Example 4, and perform demulsification experiments according to the "Light Crude Oil" implementation standard in the "General Technical Conditions for Crude Oil Demulsifiers" (SY / T5280-2018). Figure 2a and Figure 2b As shown, Figure 2a This is a schematic diagram of the zero time of adding demulsifier. Figure 2b This is a schematic diagram of the reaction mixture after standing for 5 hours after adding the demulsifier. The concentrations of the added nano-demulsifier are 0.1%, 0.5%, 1.0%, 1.5% and 2.0% from left to right, and the dehydration rates are 92.8%, 94.3%, 95.5%, 95.2% and 94.6%, respectively.

[0064] The nano-emulsifier prepared in Example 4 of the present invention with relatively mild reaction conditions was selected for comparison with existing research results. The results showed that the nano-emulsifier prepared in the present invention was superior to the demulsifiers of Comparative Examples 1-3 in terms of usage concentration and demulsification performance. The nano-emulsifier prepared in the present invention has good demulsification performance and can significantly improve the oil-water separation efficiency of gas well condensate emulsion.

[0065] Exemplary Embodiment 3

[0066] This exemplary embodiment provides an application of a condensate oil nano-emulsifier.

[0067] The application of the condensate oil nano-emulsifier may include application in the process of condensate oil emulsion demulsification.

[0068] In summary, the advantages of the present invention include at least one of the following:

[0069] (1) The condensate oil nano-emulsifier provided by the present invention has good compatibility with other water-based systems and can be directly put into use without purification.

[0070] (2) The condensate oil nano-emulsifier provided by the present invention has excellent performance and is used for reverse demulsification treatment of water-in-oil system emulsions. It has a good demulsification effect on condensate oil emulsions and can significantly improve the oil-water separation efficiency of condensate oil emulsions.

[0071] Although the condensate oil nano-emulsifier and its preparation method and application of the present invention have been described above in combination with exemplary embodiments, it should be clear to those skilled in the art that various modifications and changes may be made to the exemplary embodiments of the present invention without departing from the spirit and scope defined by the claims.

Claims

1. A method for preparing a condensate oil nano-emulsifier, characterized in that: The preparation method comprises the following steps: S1, adding 1,3-propylenediamine and methyl acrylate to an ethanol solution containing sodium ethoxide to react and obtain a prepolymer; S2, adding nano-silica and a coupling agent to an ethanol solution, adjusting the pH, reacting, and obtaining a modified body; S3, adding the obtained prepolymer and modified product into an ethanol solution containing sodium ethoxide, reacting to obtain a condensate oil nano-emulsifier.

2. The method for preparing the condensate oil nano-emulsifier according to claim 1, characterized in that: In step S1, the ratio of the sodium ethoxide to the ethanol is 1: (0.1-2) g / L, the ratio of the 1,3-propylenediamine to the ethanol is 1: (0.1-2) mol / L, and the molar ratio of the 1,3-propylenediamine to the methyl acrylate is 1: (1-8).

3. The method for preparing the condensate oil nano-emulsifier according to claim 1, characterized in that: In step S2, the ratio of the silicon dioxide to the ethanol is 1:(0.01-0.1) g / L, and the mass ratio of the nano-silica to the coupling agent is 1:(0.05-0.2).

4. The method for preparing the condensate oil nano-emulsifier according to claim 1, characterized in that: In step S3, the ratio of the sodium ethoxide to the ethanol is 1:(0.1-2) g / L.

5. The method for preparing the condensate oil nano-emulsifier according to claim 1, characterized in that: In step S1, the reaction temperature is 50-90°C and the reaction time is 4-12 hours; in step S2, the reaction temperature is 40-80°C and the reaction time is 1-4 hours; in step S3, the reaction temperature is 60-120°C and the reaction time is 4-24 hours.

6. The method for preparing the condensate oil nano-emulsifier according to claim 1, characterized in that: The coupling agent includes at least one of vinyl triethoxysilane, vinyl trimethoxysilane, methacryloxypropyl trimethoxysilane, 3-aminopropyl trimethoxysilane, 3-aminopropyl triethoxysilane or N-2-aminoethyl-3-aminopropyl trimethoxysilane; The nano silicon dioxide is hydrophilic nano silicon dioxide, and its particle size is 5-20nm.

7. The method for preparing a condensate oil nano-emulsifier according to claim 1, characterized in that: The reagent used for adjusting the pH includes hydrochloric acid; the pH of the solution after adjusting the pH is 1-7.

8. A condensate oil nano-emulsifier, characterized in that: The condensate oil nano-emulsifier is prepared by the preparation method of the condensate oil nano-emulsifier according to any one of claims 1 to 7.

9. The condensate oil nano-emulsifier according to claim 8, characterized in that: The condensate oil nano-emulsifier is a spatial network structure polymer with nano-silicon dioxide as the core connection point, and the size of the repeating unit structure is 100-200nm.

10. Use of the condensate oil nano-emulsifier according to claim 9 in a condensate oil emulsion demulsification process.

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