A dual-solvent demulsification and viscosity reduction integrated agent for shale oil and a preparation method and application thereof

Abstract

The application provides a dual-repellent demulsification and viscosity reduction integrated agent for shale oil and a preparation method and application thereof. The dual-repellent demulsification and viscosity reduction integrated agent for shale oil has the structure shown in the following formula I, and the preparation method comprises the following steps: reacting a fluorine-containing alkyl iodine R1I and N, N, N', N'-tetramethyl alkyl diamine II in acetonitrile to generate a single quaternary ammonium salt intermediate III; reacting polyether amine IV and chloroacetic acid under the action of an alkali to obtain an intermediate product; performing a chlorination reaction on the obtained intermediate product and SOCl2 in dichloromethane to generate a polyether acetyl chloride derivative V; performing an amidation-quaternary ammonium saltization synergistic reaction on the single quaternary ammonium salt intermediate III and the polyether acetyl chloride derivative V in isopropyl alcohol; after the reaction is completed, the solvent is removed, and washing and drying are performed to obtain the dual-repellent demulsification and viscosity reduction integrated agent. The dual-repellent demulsification and viscosity reduction integrated agent can simultaneously realize rapid oil-water separation and significant reduction of the viscosity of crude oil.

Description

Technical Field

[0001] This invention relates to a dual-hydrophobic demulsifier and viscosity reducer for shale oil, its preparation method and application, belonging to the field of oilfield chemical technology. Background Technology

[0002] Shale oil, as an important unconventional oil and gas resource, faces enormous challenges in its efficient extraction and transportation. Shale oil produced fluids are typically stable water-in-oil (W / O) emulsions containing large amounts of colloids, asphaltene, nano-sized rock particles, and formation water. These natural emulsifiers form a robust interfacial film, resulting in extremely stable emulsions with very high viscosity, which poses significant difficulties for subsequent oil-water separation and pipeline transportation.

[0003] Currently, shale oil processing typically employs a step-by-step process of "demulsification and dehydration followed by viscosity reduction and transportation." This involves first adding a demulsifier to break up the emulsion and achieve oil-water separation, then adding a heating viscosity reducer or diluent to the dehydrated crude oil to lower its transport viscosity. This traditional process has the following drawbacks: 1. It is lengthy and costly, requiring two separate dosing systems and processing steps, resulting in high equipment investment and operating costs; 2. There are chemical compatibility issues, as demulsifiers and viscosity reducers may interact, leading to a decrease in overall effectiveness; 3. The treatment effect is limited, as traditional demulsifiers primarily target the aqueous phase and contribute little to reducing the viscosity of the crude oil itself; while viscosity reducers struggle to disrupt stable emulsion structures; 4. It cannot solve the problem of emulsion regeneration, as residual emulsifiers and mechanical shear forces during transportation may cause the emulsion to reform.

[0004] In recent years, although some studies have attempted to develop chemical agents that combine demulsifier and viscosity reducer functions, most approaches involve physically combining demulsifiers and viscosity reducers, failing to fundamentally solve the core problem of interfacial stability. For example, Chinese patent document CN109294548A discloses a demulsifier and viscosity reducer whose active ingredients include triethanolamine dodecylbenzenesulfonate, fatty alcohol polyoxyethylene ether, castor oil polyoxyethylene ether, ethylene glycol butyl ether, hexadecyltrimethylammonium bromide, sodium iron diethylenetriaminepentaacetate, oil-soluble comb polymer, and methanol. However, it is essentially a combination of multiple surfactants, with limited functional synergy. Chinese patent document CN118496127A discloses a shale oil demulsifier and viscosity reducer, prepared as follows: Laurylamine dipropylenediamine, an aqueous ethanol solution, and sodium 3-chloro-2-hydroxypropanesulfonate are added to a reactor while stirring and adding sodium hydroxide solution dropwise, maintaining the pH at 7-8, and reacting for 30-60 minutes. Bromosuccinic acid is then added to the reactor, and while stirring and heating to 50-60°C, sodium hydroxide solution is added dropwise, maintaining the pH at 8-9, and reacting for 60-120 minutes, after which stirring and heating are stopped. The mixture in the reactor is then adjusted to pH 2-3, a solid precipitates, is filtered, and dried to obtain the demulsifier and viscosity reducer. This shale oil demulsifier and viscosity reducer reacts with amine compounds and halocarboxylic acids. Its molecular structure lacks strong hydrophobic and oleophobic groups and highly efficient penetrating and dispersing units, resulting in limited interfacial disruption ability and viscosity reduction effect, and its surface activity is relatively weak. Chinese patent document CN120005201A provides a method for preparing a crude oil demulsifier, comprising the following steps: (1) adding polyethylene glycol monomethyl ether, ethylenediamine-N,N'-diacetic acid, and p-toluenesulfonic acid to toluene, heating to the reaction temperature, followed by vacuum distillation, washing, and drying to obtain an intermediate; (2) adding the intermediate, catalyst, and 4-chloromethylbenzoic acid (polyethylene glycol monomethyl ether) ester to N,N-dimethylformamide to carry out a substitution reaction, then adding 4-chloromethylbenzoic acid (polyethylene glycol monomethyl ether) ester to carry out a quaternization reaction, followed by vacuum distillation, washing, and drying to obtain a crude oil demulsifier. This crude oil demulsifier focuses on the hydrophilicity regulation of the polyether chain and does not contain a fluorocarbon chain or other amphiphilic structure, thus failing to achieve viscosity reduction of the crude oil bulk. Furthermore, the preparation process uses toxic solvents such as toluene and N,N-dimethylformamide, resulting in poor environmental performance.

[0005] Currently, existing technologies lack a single-molecule processing agent capable of actively and efficiently disrupting highly stable interfacial films while simultaneously significantly reducing system viscosity. Therefore, developing a novel, highly efficient chemical agent that integrates demulsification and viscosity reduction in shale oil produced fluids is of urgent practical significance for simplifying shale oil processing procedures, reducing operating costs, and improving economic efficiency. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a dual-hydrophobic demulsifier and viscosity reducer for shale oil, along with its preparation method and application. The purpose of this invention is to overcome the deficiencies of existing step-by-step processing techniques and compounded agents, providing a unique dual-hydrophobic agent capable of achieving efficient demulsification and deep viscosity reduction in shale oil produced fluids. This dual-hydrophobic demulsifier and viscosity reducer is a gemini quaternary ammonium salt surfactant with a rigid-flexible asymmetric structure. This molecular structure integrates three functional units: a fluorocarbon chain (strongly hydrophobic and oleophobic), a quaternary ammonium salt cationic head (strong adsorption), and a polyether chain (penetration and dispersion), enabling simultaneous rapid oil-water separation and a significant reduction in crude oil viscosity.

[0007] The technical solution of the present invention is as follows:

[0008] A dual-repellent demulsifier and viscosity reducer for shale oil has the structure shown in Formula I:

[0009]

[0010] In Equation I, R1 is C6-C 12 Fluorinated alkyl groups; n is an integer from 1 to 6, a is an integer from 5 to 50, and b is an integer from 1 to 50.

[0011] According to a preferred embodiment of the present invention, the fluorinated alkyl group is a perfluorinated straight-chain alkyl group or a methyl-terminated fluorinated straight-chain alkyl group.

[0012] According to the present invention, the preparation method of the above-mentioned dual-repellent demulsifier and viscosity reducer for shale oil includes the following steps:

[0013] (1) Fluoroalkyl iodine R1I is reacted with N,N,N',N'-tetramethylalkyldiamine II in acetonitrile to generate monoquaternary ammonium salt intermediate III;

[0014]

[0015] Wherein, the substituents R1,n are as described in Formula I;

[0016] (2) Polyetheramine IV was reacted with chloroacetic acid under alkaline conditions to obtain an intermediate product; the obtained intermediate product was chlorinated with SOCl2 in dichloromethane to generate polyetheracetyl chloride derivative V;

[0017]

[0018] Wherein, a and b are as described in Equation I;

[0019] (3) The monoquaternary ammonium salt intermediate III obtained in step (1) and the polyether acetyl chloride derivative V obtained in step (2) are reacted in isopropanol; after the reaction is completed, the solvent is removed, and the product is washed and dried to obtain a dual-hydrophobic demulsifier and viscosity reducer for shale oil.

[0020] According to a preferred embodiment of the present invention, the molar ratio of the fluorinated alkyl iodine R1I to N,N,N',N'-tetramethylalkyldiamine II in step (1) is 1:1.

[0021] According to a preferred embodiment of the present invention, the volume ratio of acetonitrile to the molar number of fluorinated alkyl iodine R1I in step (1) is 100-150 mL: 0.1 mol.

[0022] According to a preferred embodiment of the present invention, the temperature of the reaction in step (1) is 70-80°C and the reaction time is 10-14h.

[0023] According to a preferred embodiment of the present invention, in step (1), after the reaction is completed, a post-processing step is further included: removing the solvent from the obtained reaction solution, dissolving the obtained crude product in n-hexane, washing the organic phase three times with deionized water, drying the obtained organic phase with anhydrous sodium sulfate, removing the solvent, and obtaining monoquaternary ammonium salt intermediate III; the volume ratio of n-hexane to the molar number of fluorinated alkyl iodine R1I is 40-60 mL: 0.1 mol, and the volume ratio of deionized water to n-hexane used for each wash is 0.5-1:1.

[0024] According to a preferred embodiment of the present invention, the molar ratio of chloroacetic acid to polyetheramine IV in step (2) is 1-1.2:1.

[0025] According to a preferred embodiment of the present invention, the alkali in step (2) is sodium hydroxide, and the molar ratio of the alkali to chloroacetic acid is 1-1.1:1.

[0026] According to a preferred embodiment of the present invention, in step (2), the reaction temperature of polyetheramine IV and chloroacetic acid under alkaline conditions is 40-50°C, and the reaction time is 4-6 hours.

[0027] According to a preferred embodiment of the present invention, after the reaction of polyetheramine IV and chloroacetic acid under alkaline conditions in step (2) is completed, a post-processing step is further included, as follows: after the reaction is completed, the mixture is naturally cooled to room temperature, and deionized water is added. The ratio of the volume of deionized water added to the molar number of polyetheramine IV is 40-60 mL: 0.1 mol. Then, the pH is adjusted to 2-3 using a 1 mol / L hydrochloric acid solution, and the mixture is allowed to stand for 30-60 min to precipitate a solid. After filtration, the obtained solid is washed 2-4 times with deionized water and then vacuum dried at 50-60°C to constant weight to obtain an intermediate product.

[0028] According to a preferred embodiment of the present invention, the molar ratio of SOCl2 to polyetheramine IV in step (2) is 1.2-1.5:1.

[0029] According to a preferred embodiment of the present invention, the volume ratio of dichloromethane to the molar ratio of polyetheramine IV in step (2) is 20-50 mL: 0.1 mol.

[0030] According to a preferred embodiment of the present invention, the temperature of the chlorination reaction in step (2) is 25-35°C and the chlorination reaction time is 3-5 hours.

[0031] According to a preferred embodiment of the present invention, in step (2), after the chlorination reaction is completed, a post-processing step is further included, specifically as follows: the obtained reaction solution is distilled under reduced pressure to remove dichloromethane and excess SOCl2, the obtained residue is washed with petroleum ether 2-3 times, and dried under vacuum at 50-60°C to constant weight to obtain polyether acetyl chloride derivative V.

[0032] According to a preferred embodiment of the present invention, the molar ratio of the monoquaternary ammonium salt intermediate III to the polyether acetyl chloride derivative V in step (3) is 1:1.8-2.0.

[0033] According to a preferred embodiment of the present invention, the volume ratio of isopropanol in step (3) to the molar ratio of monoquaternary ammonium salt intermediate III is 120-180 mL: 1 mol.

[0034] According to a preferred embodiment of the present invention, the temperature of the reaction in step (3) is 70-80°C and the reaction time is 20-36h.

[0035] According to a preferred embodiment of the present invention, the washing in step (3) is washing with petroleum ether 3-5 times, and the drying is vacuum drying at 60-80°C to constant weight.

[0036] According to the present invention, the application of the above-mentioned dual-hydrophobic demulsifier and viscosity reducer for shale oil in shale oil processing is as follows: the dual-hydrophobic demulsifier and viscosity reducer for shale oil is directly added to the shale oil produced fluid at a concentration of 50-200 mg / L, and stirred or allowed to stand at 40-70°C, so that rapid oil-water separation and significant reduction of crude oil viscosity can be achieved simultaneously.

[0037] The technical features and beneficial effects of this invention are as follows:

[0038] 1. Strong interfacial adsorption and membrane replacement: The integrated agent head of the present invention preferentially adsorbs onto the negatively charged oil-water interface through strong electrostatic interaction. Its rigid structure and high charge density can effectively replace the original natural emulsifier (such as asphaltene), weakening the strength and toughness of the interfacial film.

[0039] 2. Dual hydrophobic properties induce interfacial instability: The fluorocarbon chain at one end of the integrated agent molecule of the present invention has extremely low surface energy and is both hydrophobic and oleophobic. Its directional arrangement at the interface greatly reduces the interfacial tension and disrupts the original hydrophilic-oleophilic balance (HLB) of the interfacial film, leading to the aggregation of emulsion droplets.

[0040] 3. Penetration and viscosity reduction of polyether chains: The polyether chain (polyoxyethylene EO-polyoxypropylene PO block copolymer) at the other end of the integrated agent molecule of the present invention can penetrate deep into the crude oil matrix. Through solvation and steric hindrance, it can effectively break down the aggregate network structure formed by the colloids and asphaltenes through hydrogen bonds and π-π stacking, thereby significantly reducing the bulk viscosity of the crude oil after dehydration.

[0041] 4. Synergistic effect of "one body, two sides": The integrated agent molecule of the present invention is like a "two-faced person". One end (fluorocarbon chain) is dedicated to "destruction" (demulsification) at the interface, while the other end (polyether chain) is dedicated to "construction" (disassembling structure and reducing viscosity) in the oil phase. The two work together through rigid connecting groups to achieve efficient unity of interfacial demulsification and bulk viscosity reduction.

[0042] Compared with the prior art, the present invention has the following significant advantages:

[0043] 1. Integrated processing, simplified process: One agent simultaneously completes the two key steps of demulsification and viscosity reduction, which greatly simplifies the ground treatment process and reduces equipment and operating costs.

[0044] 2. High processing efficiency and excellent results: Due to its unique molecular structure, it has a faster demulsification speed and a higher dehydration rate for stubborn shale oil emulsions, while reducing crude oil viscosity by more than an order of magnitude.

[0045] 3. Synergistic function and stable performance: The demulsification and viscosity reduction functions originate from different parts of the same molecule, so there are no compatibility issues and the performance is stable and reliable.

[0046] 4. Strong applicability: It is particularly suitable for complex shale oil produced fluid systems containing a large amount of colloids, asphalt, and nanoparticles.

[0047] 5. Low dosage and good economy: Due to its twin structure, it has high surface activity and can achieve excellent results at a low concentration. Attached Figure Description

[0048] Figure 1 The 1H NMR spectrum of the dual-hydrophobic demulsifier and viscosity reducer for shale oil prepared in Example 1.

[0049] Figure 2 The infrared spectrum of the dual-hydrophobic demulsifier and viscosity reducer for shale oil prepared in Example 1. Detailed Implementation

[0050] The present invention will be described in detail below through specific embodiments, but the present invention is not limited thereto.

[0051] Unless otherwise specified, all raw materials used in the examples are commercially available products.

[0052] Example 1

[0053] A method for preparing a dual-repellent demulsifier and viscosity reducer for shale oil includes the following steps:

[0054] (1) 0.1 mol of perfluorohexyl iodine and 0.1 mol of N,N,N',N'-tetramethylethylenediamine were simultaneously added dropwise to 120 mL of acetonitrile for 1 h. After the addition was completed, the reaction was carried out at 70 °C for 8 h, and then the temperature was raised to 80 °C and the reaction was continued for 4 h. After the reaction was completed, the solvent was removed by vacuum distillation. The residue was dissolved in 50 mL of n-hexane and then the organic phase was washed three times with deionized water, using 30 mL of deionized water each time. The organic phase obtained by washing was dried with anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure at 45 °C until no fraction dripped out, to obtain monoquaternary ammonium salt intermediate III.

[0055] (2) Mix 0.1 mol polyetheramine IV (a=15, b=15) with 0.11 mol chloroacetic acid, add 0.11 mol sodium hydroxide, and stir at 45°C for 5 hours. After the reaction is complete, cool naturally to room temperature, add 50 mL deionized water, adjust the pH to 2.5 with 1 mol / L hydrochloric acid solution, let stand for 40 min, precipitate solid, filter, wash the obtained solid with deionized water 3 times, and dry the washed solid under vacuum at 60°C to constant weight to obtain intermediate product. Add the obtained intermediate product to 30 mL dichloromethane, then add 0.12 mol SOCl2, and react at 30°C for 4 hours. After the reaction is complete, remove the solvent and excess SOCl2 by vacuum distillation of the obtained reaction solution, wash the obtained solid with petroleum ether 3 times, and then dry under vacuum at 60°C to constant weight to obtain polyether acetyl chloride derivative V.

[0056] (3) Add 0.04 mol of monoquaternary ammonium salt intermediate III and 0.08 mol of polyether acetyl chloride derivative V to 6 mL of isopropanol and react at 80 °C for 24 hours. After the reaction is completed, remove the solvent by rotary evaporation of the obtained reaction solution. Wash the obtained solid with petroleum ether 4 times, each time using 150 mL of petroleum ether. Then dry it under vacuum at 70 °C to constant weight to obtain a light yellow waxy solid product, which is the dual-hydrophobic demulsifier and viscosity reducer for shale oil.

[0057] The reaction route in this embodiment is as follows:

[0058]

[0059] In the above formula, R1 is a linear perfluorohexyl group.

[0060] The 1H NMR spectrum and infrared spectrum of the product obtained in this embodiment are as follows: Figure 1 and Figure 2 As shown. By Figure 1 (NMR spectrum, CDCl3 as solvent) It can be seen that the methyl proton peak in the polyether chain appears at δ=0.8-1.2ppm, the methylene proton peak of the linker is at δ=1.5-2.0ppm, the characteristic peak of the methyl group linked to the nitrogen atom of the quaternary ammonium salt is at δ=3.2-3.5ppm, the proton peak of the oxymethylene group in the polyether chain is at δ=3.5-4.0ppm, and the proton peak of the methylene group adjacent to the cationic head group of the quaternary ammonium salt (-CH2-N) is at δ=4.5-5.0ppm. + The proton peak of (CH3)2- confirms the existence of various functional units in the molecule; Figure 2 (Infrared absorption spectrum) shows that 1100-1200cm -1 The characteristic absorption peak of the CF bond appears at 1470 cm⁻¹. -1 The location is quaternary ammonium salt N + The characteristic absorption peak at 1720 cm⁻¹ -1 The peak at 2800-3000 cm⁻¹ is a characteristic absorption peak for the carbonyl group (C=O) in an amide bond. -1 The peak at this point represents the stretching vibration of the CH bond in the polyether chain, confirming the successful synthesis of the target product.

[0061] Example 2

[0062] A method for preparing a dual-hydrophobic demulsifier and viscosity reducer for shale oil is described in Example 1, except that perfluorooctyl iodine is used instead of perfluorohexyl iodine in step (1).

[0063] Example 3

[0064] A method for preparing a dual-hydrophobic demulsifier and viscosity reducer for shale oil is described in Example 1, except that N,N,N',N'-tetramethylhexanediamine is used instead of N,N,N',N'-tetramethylethylenediamine in step (1).

[0065] Example 4

[0066] A method for preparing a dual-hydrophobic demulsifier and viscosity reducer for shale oil is described in Example 1, except that in step (2), a in polyetheramine IV is 18 and b is 6.

[0067] Example 5

[0068] A method for preparing a dual-hydrophobic demulsifier and viscosity reducer for shale oil is described in Example 1, except that the reaction temperature in step (3) is 70°C and the reaction time is 36 hours.

[0069] Comparative Example 1

[0070] Traditional demulsifier: Phenolic resin polyether type demulsifier (SP-169).

[0071] Comparative Example 2

[0072] Physical compounding agent: Equal masses of demulsifier from Comparative Example 1 and viscosity reducer sodium dodecylbenzenesulfonate are physically mixed.

[0073] Comparative Example 3

[0074] A demulsifier for shale oil is described in Example 1, except that steps (2)-(3) are not performed.

[0075] Comparative Example 4

[0076] A twin quaternary ammonium salt surfactant for shale oil is described in Example 1, except that perfluorohexyl iodine is replaced with n-hexyl iodine in step (1).

[0077] Test case

[0078] The following performance tests were performed on the products prepared in the examples and comparative examples.

[0079] 1. Demulsification performance test

[0080] Take 100 mL of produced fluid from a shale oil field (water content 35%, apparent viscosity at 50℃ is 850 mPa·s) into a stoppered graduated cylinder, add the test reagent at a concentration of 100 mg / L, let stand in a 60℃ water bath, record the amount of water removed at different times, and calculate the dehydration rate. Dehydration rate = (actual amount of water removed / theoretical total water content) × 100%. The results are shown in Table 1.

[0081] Table 1. Results of demulsification and dehydration performance tests (dehydration rate %)

[0082]

[0083] 2. Viscosity Reduction Performance Test

[0084] The apparent viscosity of the purified oil after demulsification and dehydration (taken from the upper oil phase after 24 hours) was measured at 50°C, and the results are shown in Table 2.

[0085] Table 2. Results of viscosity reduction performance test

[0086]

[0087] 3. Interface tension test

[0088] The dynamic interfacial tension between the aqueous solution (concentration of 100 mg / L) of the dual-hydrophobic demulsifier and viscosity reducer for shale oil prepared in Example 1 and shale oil was measured. The results showed that the interfacial tension was 0.085 mN / m at 10 s, 0.021 mN / m at 20 s, and decreased to 0.005 mN / m at 30 s and remained stable, confirming its strong interfacial adsorption and activation ability. The equilibrium interfacial tensions at different concentrations (50 mg / L, 100 mg / L, 200 mg / L) were 0.012 mN / m, 0.005 mN / m, and 0.004 mN / m, respectively, indicating that the interfacial activity increased with increasing concentration but the marginal effect decreased.

[0089] In summary, the dual-hydrophobic demulsifier and viscosity reducer for shale oil prepared in this embodiment of the invention exhibits a demulsification speed far faster than traditional agents and a higher final dehydration rate. Furthermore, its viscosity-reducing effect on the crude oil matrix during demulsification far surpasses that of traditional demulsifiers and physical compounding agents, truly achieving integrated and efficient processing. This invention successfully develops a dual-hydrophobic shale oil demulsifier and viscosity reducer, providing strong technical support for the efficient and economical development of shale oil.

Claims

1. A dual-repellent demulsifier and viscosity reducer for shale oil, characterized in that, It has the structure shown in Equation I: In Equation I, R1 is C6-C 12 Fluorinated alkyl groups; n is an integer from 1 to 6, a is an integer from 5 to 50, and b is an integer from 1 to 50.

2. The dual-repellent demulsifier and viscosity reducer for shale oil according to claim 1, characterized in that, The fluorinated alkyl group is a perfluorinated straight-chain alkyl group or a methyl-terminated fluorinated straight-chain alkyl group.

3. The preparation method of the dual-hydrophobic demulsifier and viscosity reducer for shale oil as described in claim 1 or 2, characterized in that, The steps include the following: (1) Fluoroalkyl iodine R1I is reacted with N,N,N',N'-tetramethylalkyldiamine II in acetonitrile to generate monoquaternary ammonium salt intermediate III; Wherein, the substituents R1,n are as described in Formula I; (2) Polyetheramine IV was reacted with chloroacetic acid under alkaline conditions to obtain an intermediate product; the obtained intermediate product was chlorinated with SOCl2 in dichloromethane to generate polyetheracetyl chloride derivative V; Wherein, a and b are as described in Equation I; (3) The monoquaternary ammonium salt intermediate III obtained in step (1) and the polyether acetyl chloride derivative V obtained in step (2) are subjected to an amidation-quaternization synergistic reaction in isopropanol; after the reaction is completed, the solvent is removed, and the product is washed and dried to obtain a dual-hydrophobic demulsifier and viscosity reducer for shale oil.

4. The preparation method of the dual-repellent demulsifier and viscosity reducer for shale oil according to claim 3, characterized in that, The molar ratio of the fluorinated alkyl iodine R1I to N,N,N',N'-tetramethylalkyldiamine II in step (1) is 1:

1.

5. The preparation method of the dual-repellent demulsifier and viscosity reducer for shale oil according to claim 3, characterized in that, In step (1), the volume ratio of acetonitrile to the molar ratio of fluorinated alkyl iodine R1I is 100-150 mL: 0.1 mol; the reaction temperature is 70-80 °C; and the reaction time is 10-14 h. In step (1), after the reaction is completed, a post-processing step is also included: the solvent is removed from the obtained reaction solution, the crude product is dissolved in n-hexane, and then the organic phase is washed three times with deionized water. The obtained organic phase is dried with anhydrous sodium sulfate and the solvent is removed to obtain monoquaternary ammonium salt intermediate III. The volume ratio of n-hexane to the molar number of fluorinated alkyl iodine R1I is 40-60 mL: 0.1 mol, and the volume ratio of deionized water to n-hexane used for each wash is 0.5-1:

1.

6. The preparation method of the dual-repellent demulsifier and viscosity reducer for shale oil according to claim 3, characterized in that, In step (2), the molar ratio of chloroacetic acid to polyetheramine IV is 1-1.2:1; the alkali is sodium hydroxide, and the molar ratio of the alkali to chloroacetic acid is 1-1.1:1; The reaction temperature of polyetheramine IV with chloroacetic acid under alkaline conditions is 40-50℃, and the reaction time is 4-6 hours. After the reaction of polyetheramine IV with chloroacetic acid under alkaline conditions is completed, a post-treatment step is also included, as follows: After the reaction is completed, the mixture is naturally cooled to room temperature, and deionized water is added. The volume ratio of the added deionized water to the molar number of polyetheramine IV is 40-60 mL: 0.1 mol. Then, the pH is adjusted to 2-3 using a 1 mol / L hydrochloric acid solution, and the mixture is allowed to stand for 30-60 min to precipitate a solid. After filtration, the obtained solid is washed 2-4 times with deionized water and then vacuum dried at 50-60℃ to constant weight to obtain the intermediate product.

7. The preparation method of the dual-repellent demulsifier and viscosity reducer for shale oil according to claim 3, characterized in that, In step (2), the molar ratio of SOCl2 to polyetheramine IV is 1.2-1.5:1; the volume ratio of dichloromethane to the molar number of polyetheramine IV is 20-50 mL: 0.1 mol; the chlorination reaction temperature is 25-35℃, and the chlorination reaction time is 3-5 h. After the chlorination reaction is completed, a post-processing step is also included, as follows: the obtained reaction solution is distilled under reduced pressure to remove dichloromethane and excess SOCl2, the residue is washed 2-3 times with petroleum ether, and dried under vacuum at 50-60℃ to constant weight to obtain polyether acetyl chloride derivative V.

8. The preparation method of the dual-repellent demulsifier and viscosity reducer for shale oil according to claim 3, characterized in that, In step (3), the molar ratio of the monoquaternary ammonium salt intermediate III to the polyether acetyl chloride derivative V is 1:1.8-2.0; the volume ratio of the isopropanol to the molar number of the monoquaternary ammonium salt intermediate III is 120-180 mL:1 mol.

9. The preparation method of the dual-repellent demulsifier and viscosity reducer for shale oil according to claim 3, characterized in that, The reaction temperature in step (3) is 70-80℃, the reaction time is 20-36h; the washing is performed by washing with petroleum ether 3-5 times, and the drying is performed by vacuum drying at 60-80℃ to constant weight.

10. The application of the dual-repellent demulsifier and viscosity reducer for shale oil as described in claim 1 or 2 in shale oil processing, characterized in that, The specific application method is as follows: add the dual-hydrophobic demulsifier and viscosity reducer for shale oil directly to the shale oil produced fluid at a concentration of 50-200 mg / L, and stir or let it stand at 40-70℃ to achieve oil-water separation and crude oil viscosity reduction at the same time.

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