Modified hydrogen-containing silicon modified oil polyether demulsifier and preparation method thereof

Abstract

The invention relates to a modified hydrogen-silicon-containing modified oil polyether demulsifier and a preparation method thereof, and belongs to the technical field of oil field chemicals. The preparation method comprises the following steps: carrying out polymerization reaction on modified polyether taking an amino-modified molybdenum disulfide nanosheet as an initiator, hydrogen-containing silicone oil block polyether modified by a silane coupling agent and quaternary ammonium salt containing a furan structure under the action of ammonium persulfate and a silicon-containing reducing agent to form a high-molecular-weight inorganic hybrid polymer composite structure; the surface activity can be further improved, and the demulsification effect is enhanced. The furan ring, quaternary ammonium salt, organic silicon, block polyether and molybdenum disulfide nanosheets in the molecular structure play a role together, so that the demulsifier is easier to dissolve natural emulsifiers such as colloid, asphaltene and solid powder adsorbed on an oil-water interface, and an interfacial film formed by the natural emulsifiers is prevented from hindering water drop coalescence; and the demulsifying agent can more easily and rapidly penetrate through an emulsion external phase to be dispersed on an oil-water interface so as to play a demulsification role.

Description

Technical Field

[0001] The invention relates to a modified hydrogen-containing silicon-modified oil polyether demulsifier and a preparation method thereof, belonging to the technical field of oilfield chemicals. Background Art

[0002] High-sulfur heavy crude oil is a low-quality crude oil that is difficult to process. It is generally cycloalkane or intermediate-base crude oil. Its main characteristics are high density, high viscosity, low freezing point, high residual carbon value and sulfur content. Due to the small difference in oil-water density and the relatively stable thick emulsion layer at the oil-water interface, it is extremely difficult to dehydrate high-sulfur heavy crude oil. In addition, during the mining process of heavy crude oil, a large number of production-enhancing recovery technologies such as gas injection and acid fracturing are used, resulting in significant changes in the physical properties of the produced crude oil, which are manifested in increased crude oil viscosity and a significant increase in micro-solid impurities in the crude oil. The micro-solid phase makes the emulsified state of crude oil more complicated, which further increases the difficulty of crude oil dehydration. Moreover, when conventional demulsifiers are used to treat high-sulfur heavy crude oil, the dehydrated wastewater contains a high amount of oil, which increases the difficulty and cost of wastewater treatment.

[0003] At present, chemical demulsifiers for high-sulfur heavy crude oil are mainly obtained by compounding multiple surfactants. For example, patent document CN103361108B discloses a demulsifier suitable for high-sulfur and high-salt produced crude oil emulsions, including the following raw materials in weight percentage: 60% to 65% silicon-containing surfactants, 1% to 5% olefin copolymers, and 25% to 30% polar solvents. The demulsifier disclosed in the patent needs to play a good demulsification effect at 110°C, and the demulsification effect at room temperature is poor, which is not conducive to large-scale processing. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a modified hydrogenated silicon modified oil polyether demulsifier, which can solve the problem that the currently prepared demulsifier has poor demulsification effect at room temperature when used for demulsification of high-sulfur and high-salt produced liquid crude oil emulsion.

[0005] Another object of the present invention is to provide a modified hydrogenated silicon modified oil polyether demulsifier, which can solve the problem that the current demulsifier has poor demulsification effect at room temperature when used for demulsification of high-sulfur and high-salt produced liquid crude oil emulsions.

[0006] The present invention provides a method for preparing a modified hydrogen-containing silicon-modified oil polyether demulsifier, comprising the following steps: (1) reacting amino-modified molybdenum disulfide nanosheets and a chain extender in the presence of an etherification catalyst to obtain a nano-modified polyether, wherein the chain extender is ethylene oxide and / or propylene oxide; then reacting the nano-modified polyether with acryloyl chloride to obtain an olefin-modified polyether; the mass ratio of the amino-modified molybdenum disulfide nanosheets to the chain extender is 30:(150-300), and the mass of the acryloyl chloride is 0.2-0.5% of the mass of the nano-modified polyether; (2) reacting an initiator, ethylene oxide and propylene oxide in the presence of an etherification catalyst to obtain a block polyether, and then reacting the block polyether with propenyltrimethoxysilane to obtain an olefin block polyether; the mass ratio of the initiator, ethylene oxide and propylene oxide is 5:(250-350):(100-150); the initiator is composed of diethanolamine and hydrogenated silicone oil in a mass ratio of (2-3):(2-3); (3) Respectively reacting 2,5-furan dimethanol with acryloyl chloride and acyl chloride quaternary ammonium salt to obtain a cationic monomer; the molar ratio of 2,5-furan dimethanol, acryloyl chloride and acyl chloride quaternary ammonium salt is 1:1:1, and the chemical structure of the quaternary ammonium salt is as follows: ; (4) The alkenyl modified polyether, alkenyl block polyether and cationic monomer are polymerized under the action of an initiator to obtain a molybdenum disulfide-hydrogen silicone oil modified polyether composite demulsifier; the mass ratio of the alkenyl modified polyether, the alkenyl block polyether and the cationic monomer is (10-20):(20-30):(40-50); the initiator is composed of ammonium persulfate and a silicon-containing reducing agent, and the chemical structure of the silicon-containing reducing agent is as follows: .

[0007] Preferably, the amino-modified molybdenum disulfide nanosheets are prepared by reacting molybdenum disulfide nanosheets with γ-aminopropyltriethoxysilane, and the thickness of the molybdenum disulfide nanosheets is 10-20 nm, and the sheet diameter is 200-300 nm.

[0008] Preferably, the etherification catalyst in step (1) is sodium hydroxide or potassium hydroxide.

[0009] Preferably, the temperature for the reaction of the amino-modified molybdenum disulfide nanosheets and the chain extender is 140-150° C. and the pressure is 0.3-0.4 MPa.

[0010] Preferably, the etherification catalyst in step (2) is sodium hydroxide or potassium hydroxide.

[0011] Preferably, the preparation method of the block polyether is as follows: the initiator and propylene oxide are reacted completely under the action of an etherification catalyst at a temperature of 110-120° C. and a pressure of 0.3-0.4 MPa, and then the system after the reaction is reacted with ethylene oxide at 125-135° C. and a pressure of 0.3-0.4 MPa to obtain the block polyether; the mass fraction of Si-H groups in the hydrogenated silicone oil is 0.4%-0.6%, and the viscosity at 25° C. is 240-400. .

[0012] Preferably, the reaction temperature of the block polyether and propenyltrimethoxysilane is 80-90°C.

[0013] Preferably, the mass ratio of the alkenyl-modified polyether, alkenyl block polyether, cationic monomer, ammonium persulfate and silicon-containing reducing agent is (10-20):(20-30):(40-50):(0.7-1.2):(5-8).

[0014] Preferably, the polymerization reaction time is 3 to 5 hours.

[0015] The invention provides a modified hydrogen-containing silicon-modified oil polyether demulsifier, which is prepared by the above-mentioned preparation method of the modified hydrogen-containing silicon-modified oil polyether demulsifier.

[0016] The beneficial effects of the present invention are as follows: (1) The present invention uses amino-modified molybdenum disulfide nanosheets as a starting agent to synthesize molybdenum disulfide nanosheet-modified polyether. Due to the layered structure, steric hindrance effect and large specific surface area of ​​the molybdenum disulfide nanosheets, the polyether chain segment structure on the molybdenum disulfide nanosheet-modified polyether is more stretched and dispersed more evenly, which effectively increases the demulsification area. At the same time, the molybdenum disulfide nanosheets have good lubrication and chemical stability, which can effectively improve the demulsification effect of high-sulfur heavy crude oil.

[0017] (2) The present invention uses diethanolamine and hydrogenated silicone oil as initiators to prepare block polyethers, and the block polyethers are modified with silane coupling agents, which can effectively improve their surface properties and chemical resistance, making them more suitable for demulsification of high-sulfur heavy crude oil.

[0018] (3) The present invention utilizes 2,5-furan dimethanol to graft quaternary ammonium salt segments to prepare a new cationic monomer. The furan ring in the monomer can improve its hydrophilicity and lipophilicity. It works together with the quaternary ammonium salt group to increase the surface activity of the cationic monomer, hinder the aggregation of water droplets, and enhance the oil-water separation effect.

[0019] (4) The present invention uses ammonium persulfate and a silicon-containing reducing agent as initiators, which can reduce the reaction temperature and improve the convenience of operation. On the other hand, it can introduce organic silicon segments into the demulsifier polymer segments horizontally to overall adjust the surface activity of the demulsifier and improve the demulsification performance.

[0020] (5) The present invention further improves its surface activity and enhances the demulsification effect by polymerizing a modified polyether with amino-modified molybdenum disulfide nanosheets as an initiator, a hydrogenated silicone oil block polyether modified with a silane coupling agent, and a quaternary ammonium salt containing a furan structure under the action of ammonium persulfate and a silicon-containing reducing agent to form a large molecular weight inorganic hybrid polymer composite structure. The furan ring, quaternary ammonium salt, organic silicon, block polyether and molybdenum disulfide nanosheets in the molecular structure work together to make the demulsifier more easily dissolve the natural emulsifiers such as colloid, asphaltene, solid powder adsorbed on the oil-water interface, prevent the interface film formed by the natural emulsifier from hindering the aggregation of water droplets, and more easily and quickly pass through the outer phase of the emulsion to disperse to the oil-water interface to play a demulsification effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a comparison chart of the demulsification effects of different demulsifiers in the present invention on high-sulfur heavy crude oil (the mineralization of high-sulfur heavy crude oil is 450,000 mg / L, the sulfur content is 6%, and the colloid and asphalt content is 45%) Figure 2 The figure is a comparison chart of the demulsification effects of different demulsifiers in the present invention on high-sulfur heavy crude oil (the mineralization of the high-sulfur heavy crude oil is 600000 mg / L, the sulfur content is 8%, and the colloid and asphalt content is 50%). DETAILED DESCRIPTION

[0022] The following examples are intended to further illustrate the present invention rather than to limit the scope of protection of the present invention.

[0023] The preparation method of the amino-modified molybdenum disulfide nanosheets in each embodiment is as follows: Molybdenum disulfide nanosheets (thickness of 10-20 nm, sheet diameter of 200-300 nm) and γ-aminopropyltriethoxysilane were mixed, and then 0.1 mol / L hydrochloric acid was added. The mass ratio of molybdenum disulfide, γ-aminopropyltriethoxysilane and hydrochloric acid was 100:600:6000. Then, the mixture was heated to 95°C and stirred for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed with anhydrous ethanol, and vacuum dried at 70°C for 18 hours to obtain amino-modified molybdenum disulfide nanosheets.

[0024] The preparation method of the quaternary ammonium chloride salt in each embodiment is as follows: ① Add 60g of acetic acid to water, adjust the pH of the solution to 1, then add 83mL of formaldehyde with a concentration of 37%, mix well, add 73g of diethylamine dropwise, stir vigorously while adding dropwise, and continuously add hydrochloric acid solution to the reaction vessel to keep the pH of the solution at 1, keep the dropping speed at 9mL / min, and stir the reaction at a constant temperature for 5h after the dropping is complete, and then perform reduced pressure distillation to obtain carboxylic acid amine; ② 159g of the carboxylic acid amine prepared in step ① was added to diethyl ether, and sodium carbonate was added thereto, the pH of the solution was adjusted to 10, the temperature was raised to 100°C until refluxed, and then 86g of chloropropane was added dropwise thereto, the dropping rate was maintained at 8mL / min, and after the dropwise addition was complete, the reaction was refluxed at a constant temperature for 8h, and then evaporated and concentrated, and separated by a chromatographic column to obtain carboxyammonium chloride; ③ Add 245g of carboxyammonium chloride prepared in step ② to 450mL of thionyl chloride, heat to 80°C and reflux for 6h, then perform vacuum distillation to obtain acyl chloride quaternary ammonium salt. The chemical structure of acyl chloride quaternary ammonium salt is as follows: .

[0025] The preparation method of the silicon-containing reducing agent in each embodiment is as follows: 1,1,3,3-tetramethyldisiloxane and 3-aminopropyltrimethoxysilane are added to a flask, and then a Custer platinum catalyst is added (the mass of the Custer platinum catalyst is 0.3% of the total mass of 1,1,3,3-tetramethyldisiloxane and 3-aminopropyltrimethoxysilane), and the reaction is stirred at room temperature until no bubbles are generated to obtain a silicon-containing reducing agent. The chemical structure of the silicon-containing reducing agent is as follows: .

[0026] The specific embodiments of the modified hydrogenated silicon-modified oil polyether demulsifier and the preparation method thereof of the present invention are as follows: Example 1

[0027] The preparation method of the modified hydrogenated silicon-modified oil polyether demulsifier of this embodiment comprises the following steps: (1) 30 g of amino-modified molybdenum disulfide nanosheets and 28 g of potassium hydroxide were added to a reactor, the temperature in the reactor was adjusted to 145° C. and the pressure was adjusted to 0.3 MPa, and then 200 g of propylene oxide was added, and the reaction was stirred at constant temperature and pressure until the propylene oxide was completely reacted to obtain a nano-modified polyether; Then, 100 g of the nano-modified polyether, 200 g of chloroform and anhydrous triethylamine as an acid-binding agent were added into a low-temperature reactor, nitrogen was introduced into the reactor, and a 10% by mass fraction of acryloyl chloride dichloromethane solution was added dropwise at 0°C (the mass of acryloyl chloride in the acryloyl chloride dichloromethane solution was 0.3% of the mass of the nano-modified polyether). After the addition was completed, the reaction was stirred at 0°C until the acryloyl chloride reacted completely, and the solvent was removed by reduced pressure distillation to obtain an olefin-modified polyether.

[0028] (2) 2 g of diethanolamine and 3 g of terminal hydrogen-containing dimethyl silicone oil (the Si-H mass fraction of terminal hydrogen-containing dimethyl silicone oil is 0.5% and the viscosity at 25°C is 260 ) and 3g potassium hydroxide are added into a reactor, the temperature in the reactor is adjusted to 110°C and the pressure is 0.3MPa, then 300g propylene oxide is added, and the reaction is stirred at constant temperature and pressure until the propylene oxide reacts completely, then the temperature is raised to 120°C, 150g ethylene oxide is added, and the reaction is stirred at constant temperature and pressure until the ethylene oxide reacts completely to obtain a block polyether; Then, 10 g of block polyether and 30 g of toluene were added to the reactor, and then propenyltrimethoxysilane was added (the mass of propenyltrimethoxysilane was 0.2% of the mass of the block polyether). The materials in the reactor were heated to 90°C, stirred to react until the propenyltrimethoxysilane reacted completely, and the solvent was removed by reduced pressure distillation to obtain the alkenyl block polyether.

[0029] (3) Add 10 mol of 2,5-furan dimethanol and 15 mol of chloroform to the reactor, then add anhydrous triethylamine as an acid-binding agent, adjust the temperature of the materials in the reactor to 0°C, dropwise add a 50% by mass fraction of acryloyl chloride dichloromethane solution (the amount of acryloyl chloride in the acryloyl chloride dichloromethane solution is equal to the amount of 2,5-furan dimethanol), after the dropwise addition, stir and react at 0°C until the acryloyl chloride reacts completely, then continue to dropwise add a 50% by mass fraction of acyl chloride quaternary ammonium salt dichloromethane solution (the amount of acyl chloride quaternary ammonium salt in the acyl chloride quaternary ammonium salt dichloromethane solution is equal to the amount of 2,5-furan dimethanol), after the dropwise addition, stir and react at 0°C until the acyl chloride quaternary ammonium salt reacts completely to obtain a cationic monomer. The chemical structure of acyl chloride quaternary ammonium salt is as follows: .

[0030] (4) Add 15g of olefin-modified polyether, 20g of olefin-block polyether and 45g of cationic monomer into a polymerization reactor, then add 100g of toluene, stir evenly, then add 0.8g of ammonium persulfate and 7g of silicon-containing reducing agent, stir and react at room temperature for 5h, heat to remove the solvent, and obtain a molybdenum disulfide-hydrogen silicone oil modified polyether composite demulsifier. The chemical structure of the silicon-containing reducing agent is as follows: .

[0031] Example 2

[0032] The preparation method of the modified hydrogenated silicon-modified oil polyether demulsifier of this embodiment comprises the following steps: (1) Add 30 g of amino-modified molybdenum disulfide nanosheets and 32 g of potassium hydroxide into a reactor, adjust the temperature in the reactor to 150 ° C and the pressure to 0.4 MPa, then add 300 g of propylene oxide (ethylene oxide), and stir the reaction at constant temperature and pressure until the propylene oxide (ethylene oxide) reacts completely to obtain a nano-modified polyether; Then, 100 g of the nano-modified polyether, 200 g of chloroform and anhydrous triethylamine as an acid-binding agent were added into a low-temperature reactor, nitrogen was introduced into the reactor, and a 10% by mass fraction of acryloyl chloride dichloromethane solution (the mass of acryloyl chloride in the acryloyl chloride dichloromethane solution was 0.5% of the mass of the nano-modified polyether) was added dropwise at 0°C. After the addition was completed, the reaction was stirred at 0°C until the acryloyl chloride reacted completely, and the solvent was removed by reduced pressure distillation to obtain an olefin-modified polyether.

[0033] (2) 3 g of diethanolamine and 2 g of terminal hydrogen-containing dimethyl silicone oil (the Si-H mass fraction of terminal hydrogen-containing dimethyl silicone oil is 0.6% and the viscosity at 25°C is 240 ) and 4g potassium hydroxide are added into a reactor, the temperature in the reactor is adjusted to 120°C and the pressure is 0.4MPa, then 350g propylene oxide is added, and the reaction is stirred at constant temperature and pressure until the propylene oxide reacts completely, then the temperature is raised to 135°C, 150g ethylene oxide is added, and the reaction is stirred at constant temperature and pressure until the ethylene oxide reacts completely to obtain a block polyether; Then, 10 g of block polyether and 30 g of toluene were added into the reactor, and then propenyltrimethoxysilane (the mass of propenyltrimethoxysilane was 0.4% of the mass of block polyether) was added, and then the materials in the reactor were heated to 90°C, stirred to react until the propenyltrimethoxysilane reacted completely, and the solvent was removed by vacuum distillation to obtain alkenyl block polyether.

[0034] (3) Add 10 mol of 2,5-furan dimethanol and 15 mol of chloroform to the reactor, then add anhydrous triethylamine as an acid-binding agent, adjust the temperature of the materials in the reactor to 0°C, dropwise add a 50% by mass fraction of acryloyl chloride dichloromethane solution (the amount of acryloyl chloride in the acryloyl chloride dichloromethane solution is equal to the amount of 2,5-furan dimethanol), after the dropwise addition, stir and react at 0°C until the acryloyl chloride reacts completely, then continue to dropwise add a 50% by mass fraction of acyl chloride quaternary ammonium salt dichloromethane solution (the amount of acyl chloride quaternary ammonium salt in the acyl chloride quaternary ammonium salt dichloromethane solution is equal to the amount of 2,5-furan dimethanol), after the dropwise addition, stir and react at 0°C until the acyl chloride quaternary ammonium salt reacts completely to obtain a cationic monomer. The chemical structure of acyl chloride quaternary ammonium salt is as follows: .

[0035] (4) Add 20g of olefin-modified polyether, 30g of olefin-block polyether and 50g of cationic monomer into a polymerization reactor, then add 100g of toluene, stir evenly, then add 0.7g of ammonium persulfate and 5g of silicon-containing reducing agent, stir and react for 4h, heat to remove the solvent, and obtain a molybdenum disulfide-hydrogen silicone oil modified polyether composite demulsifier. The chemical structure of the silicon-containing reducing agent is as follows: .

[0036] Example 3

[0037] The preparation method of the modified hydrogenated silicon-modified oil polyether demulsifier of this embodiment comprises the following steps: (1) 30 g of amino-modified molybdenum disulfide nanosheets and 25 g of potassium hydroxide were added to a reactor, the temperature in the reactor was adjusted to 140°C and the pressure was adjusted to 0.3 MPa, and then 150 g of propylene oxide (ethylene oxide) was added, and the reaction was stirred at constant temperature and pressure until the propylene oxide (ethylene oxide) was completely reacted to obtain a nano-modified polyether; Then, 100 g of the nano-modified polyether, 200 g of chloroform and anhydrous triethylamine as an acid-binding agent were added into a low-temperature reactor, nitrogen was introduced into the reactor, and a 10% by mass fraction of acryloyl chloride dichloromethane solution (the mass of acryloyl chloride in the acryloyl chloride dichloromethane solution was 0.2% of the mass of the nano-modified polyether) was added dropwise at 0°C. After the addition was completed, the reaction was stirred at 0°C until the acryloyl chloride reacted completely, and the solvent was removed by reduced pressure distillation to obtain an olefin-modified polyether.

[0038] (2) 2.5 g of diethanolamine and 2.5 g of terminal hydrogen-containing dimethyl silicone oil (the Si-H mass fraction of terminal hydrogen-containing dimethyl silicone oil is 0.4% and the viscosity at 25°C is 400 ) and 3g potassium hydroxide are added into a reactor, the temperature in the reactor is adjusted to 110°C and the pressure is 0.3MPa, then 250g propylene oxide is added, and the reaction is stirred at constant temperature and pressure until the propylene oxide reacts completely, then the temperature is raised to 125°C, 100g ethylene oxide is added, and the reaction is stirred at constant temperature and pressure until the ethylene oxide reacts completely to obtain a block polyether; Then, 10 g of block polyether and 30 g of toluene were added to the reactor, and then propenyltrimethoxysilane was added (the mass of propenyltrimethoxysilane was 0.2% of the mass of the block polyether). The materials in the reactor were heated to 80°C, stirred to react until the propenyltrimethoxysilane reacted completely, and the solvent was removed by reduced pressure distillation to obtain the alkenyl block polyether.

[0039] (3) Add 10 mol of 2,5-furan dimethanol and 15 mol of chloroform to the reactor, then add anhydrous triethylamine as an acid-binding agent, adjust the temperature of the material in the reactor to -5°C, dropwise add a 50% by mass fraction of acryloyl chloride dichloromethane solution (the amount of acryloyl chloride in the acryloyl chloride dichloromethane solution is equal to the amount of 2,5-furan dimethanol), after the dropwise addition, stir and react at 0°C until the acryloyl chloride reacts completely, then continue to dropwise add a 50% by mass fraction of acyl chloride quaternary ammonium salt dichloromethane solution (the amount of acyl chloride quaternary ammonium salt in the acyl chloride quaternary ammonium salt dichloromethane solution is equal to the amount of 2,5-furan dimethanol), after the dropwise addition, stir and react at 0°C until the acyl chloride quaternary ammonium salt reacts completely to obtain a cationic monomer. The chemical structure of acyl chloride quaternary ammonium salt is as follows: .

[0040] (4) Add 10g of olefin-modified polyether, 20g of olefin-block polyether and 40g of cationic monomer into a polymerization reactor, then add 100g of toluene, stir evenly, then add 1.2g of ammonium persulfate and 8g of silicon-containing reducing agent, stir and react for 3h, heat to remove the solvent, and obtain a molybdenum disulfide-hydrogen silicone oil modified polyether composite demulsifier. The chemical structure of the silicon-containing reducing agent is as follows: .

[0041] Example 4

[0042] The preparation method of the modified hydrogenated silicon-modified oil polyether demulsifier of this embodiment comprises the following steps: (1) 30 g of amino-modified molybdenum disulfide nanosheets and 26 g of sodium hydroxide were added to a reactor, the temperature in the reactor was adjusted to 146 ° C and the pressure was 0.35 MPa, and then 200 g of propylene oxide (ethylene oxide) was added, and the reaction was stirred at constant temperature and pressure until the propylene oxide (ethylene oxide) was completely reacted to obtain a nano-modified polyether; Then, 100 g of the nano-modified polyether, 200 g of chloroform and anhydrous triethylamine as an acid-binding agent were added into a low-temperature reactor, nitrogen was introduced into the reactor, and a 10% by mass fraction of acryloyl chloride dichloromethane solution (the mass of acryloyl chloride in the acryloyl chloride dichloromethane solution was 0.4% of the mass of the nano-modified polyether) was added dropwise at 0°C. After the addition was completed, the reaction was stirred at 0°C until the acryloyl chloride reacted completely, and the solvent was removed by reduced pressure distillation to obtain an olefin-modified polyether.

[0043] (2) 2.5 g of diethanolamine and 2.5 g of terminal hydrogen-containing dimethyl silicone oil (the Si-H mass fraction of terminal hydrogen-containing dimethyl silicone oil is 0.4% and the viscosity at 25°C is 400 ) and 3g of sodium hydroxide are added into a reactor, the temperature in the reactor is adjusted to 115°C and the pressure is 0.3MPa, then 280g of propylene oxide is added, and the reaction is stirred at a constant temperature and pressure until the propylene oxide reacts completely, then the temperature is raised to 130°C, 120g of ethylene oxide is added, and the reaction is stirred at a constant temperature and pressure until the ethylene oxide reacts completely to obtain a block polyether; Then, 10 g of block polyether and 30 g of toluene were added into the reactor, and then propenyltrimethoxysilane was added (the mass of propenyltrimethoxysilane was 0.3% of the mass of block polyether). The materials in the reactor were heated to 85°C, stirred to react until the propenyltrimethoxysilane reacted completely, and the solvent was removed by vacuum distillation to obtain alkenyl block polyether.

[0044] (3) Add 10 mol of 2,5-furan dimethanol and 15 mol of chloroform to the reactor, then add anhydrous triethylamine as an acid-binding agent, adjust the temperature of the material in the reactor to -2°C, dropwise add a 50% by mass fraction of acryloyl chloride dichloromethane solution (the amount of acryloyl chloride in the acryloyl chloride dichloromethane solution is equal to the amount of 2,5-furan dimethanol), after the dropwise addition, stir and react at 0°C until the acryloyl chloride reacts completely, then continue to dropwise add a 50% by mass fraction of acyl chloride quaternary ammonium salt dichloromethane solution (the amount of acyl chloride quaternary ammonium salt in the acyl chloride quaternary ammonium salt dichloromethane solution is equal to the amount of 2,5-furan dimethanol), after the dropwise addition, stir and react at 0°C until the acyl chloride quaternary ammonium salt reacts completely to obtain a cationic monomer. The chemical structure of acyl chloride quaternary ammonium salt is as follows: .

[0045] (4) 16 g of olefin-modified polyether, 25 g of olefin-block polyether and 40 g of cationic monomer were added to a polymerization reactor, and then 100 g of toluene was added and stirred evenly. Then 0.9 g of ammonium persulfate and 6 g of silicon-containing reducing agent were added and stirred for 4 h. The solvent was removed by heating to obtain a molybdenum disulfide-hydrogenated silicone oil modified polyether composite demulsifier. The chemical structure of the silicon-containing reducing agent is as follows: .

[0046] Example 5

[0047] The difference between the preparation method of the modified hydrogenated silicon modified oil polyether demulsifier of this embodiment and the preparation method of the modified hydrogenated silicon modified oil polyether demulsifier of Example 1 is that in the preparation method of the modified hydrogenated silicon modified oil polyether demulsifier of this embodiment, propylene oxide is replaced by ethylene oxide when preparing nano-modified polyether.

[0048] Comparative Example 1 The difference between the preparation method of the demulsifier of this comparative example and the preparation method of the demulsifier of Example 1 is that in step (3) of the preparation method of the demulsifier of this comparative example, 2,5-furan dimethanol is replaced by 3,5-pyridine dimethanol.

[0049] Comparative Example 2 The difference between the preparation method of the demulsifier of this comparative example and the preparation method of the demulsifier of Example 1 is that in step (3) of the preparation method of the demulsifier of this comparative example, 2,5-furan dimethanol is replaced by thiophene-2,5-diyl dimethanol.

[0050] Comparative Example 3 The difference between the preparation method of the demulsifier of the comparative example and the preparation method of the demulsifier of Example 1 is that in step (1) of the preparation method of the demulsifier of the comparative example, the amino-modified molybdenum disulfide nanosheets are replaced by amino-modified silica. The preparation method of the amino-modified silica is as follows: silica (particle size of 200-300 nm) and γ-aminopropyltriethoxysilane are mixed, and then 0.1 mol / L hydrochloric acid is added, and the mass ratio of silica, γ-aminopropyltriethoxysilane and hydrochloric acid is 100:600:6000, and then heated to 95°C, stirred for reaction for 12 hours, and after the reaction is completed, cooled to room temperature, filtered, washed with anhydrous ethanol, and vacuum dried at 70°C for 18 hours to obtain amino-modified silica.

[0051] Comparative Example 4 The difference between the preparation method of the demulsifier of this comparative example and the preparation method of the demulsifier of Example 1 is that in step (4) of the preparation method of the demulsifier of this comparative example, the mass of the olefin-modified polyether is adjusted to 80 g, the mass of the olefin-block polyether is adjusted to 0, and the mass of the cationic monomer is adjusted to 0.

[0052] Comparative Example 5 The difference between the preparation method of the demulsifier of this comparative example and the preparation method of the demulsifier of Example 1 is that in step (4) of the preparation method of the demulsifier of this comparative example, the mass of the olefin-modified polyether is adjusted to 0 g, the mass of the olefin-block polyether is adjusted to 80 g, and the mass of the cationic monomer is adjusted to 0.

[0053] Comparative Example 6 The difference between the preparation method of the demulsifier of this comparative example and the preparation method of the demulsifier of Example 1 is that in step (4) of the preparation method of the demulsifier of this comparative example, the mass of the olefin-modified polyether is adjusted to 0 g, the mass of the olefin-block polyether is adjusted to 0, and the mass of the cationic monomer is adjusted to 80 g.

[0054] Comparative Example 7 The difference between the preparation method of the demulsifier of this comparative example and the preparation method of the demulsifier of Example 1 is that in the preparation method of the demulsifier of this comparative example, step (3) is omitted, and the cationic monomer in step (4) is replaced by 3-acrylamidopropyltrimethylammonium chloride.

[0055] Comparative Example 8 The difference between the preparation method of the demulsifier of this comparative example and the preparation method of the demulsifier of Example 1 is that in step (2) of the preparation method of the demulsifier of this comparative example, diethanolamine is replaced by triethylenetetramine.

[0056] Comparative Example 9 The difference between the preparation method of the demulsifier of this comparative example and the preparation method of the demulsifier of Example 1 is that in step (4) of the preparation method of the demulsifier of this comparative example, the silicon-containing reducing agent is replaced by N,N-dimethylaniline.

[0057] Effect Example 1 The demulsifiers prepared in Examples 1-5 and Comparative Examples 1-8 were used in demulsification experiments. The specific steps were as follows: 10 g of high-sulfur heavy crude oil (the mineralization of high-sulfur heavy crude oil was 450,000 mg / L, the sulfur content was 6%, and the colloid and asphalt content was 45%) and 100 g of deionized water were oscillated and emulsified to prepare a crude oil emulsion, and then a demulsifier was added in an amount of 20 mg / L, stirred evenly, and allowed to stand at 35°C for 60 minutes, the water content of the oil phase was detected, and then the ratio of the water content of the oil phase to the water content of the crude oil emulsion was calculated, and then the difference between 1 and the ratio was calculated to obtain the dehydration rate, and the oil content in the water phase was tested by centrifugation. The test results of the dehydration rate and the oil content in the water phase are shown in Tables 1 and Figure 1 shown.

[0058] Table 1 Dehydration rate test results of different demulsifiers

[0059] Effect Example 2 The demulsifiers prepared in Examples 1-5 and Comparative Examples 1-8 were used in the demulsification experiment of crude oil with extra-high sulfur content. The specific steps were as follows: 10g of high-sulfur heavy crude oil (the mineralization of high-sulfur heavy crude oil was 600,000mg / L, the sulfur content was 8%, and the colloid and asphalt content was 50%) and 100g of deionized water were oscillated and emulsified to prepare a crude oil emulsion, and then a demulsifier was added in an amount of 20mg / L, stirred evenly, and allowed to stand at 45°C for 60min, the water content of the oil phase was detected, and then the ratio of the water content of the oil phase to the water content of the crude oil emulsion was calculated, and then the difference between 1 and the ratio was calculated to obtain the dehydration rate, and the oil content in the water phase was tested by centrifugation. The test results of the dehydration rate and the oil content in the water phase are shown in Tables 2 and Figure 2 shown.

[0060] Table 2 Dehydration rate test results of different demulsifiers

[0061] The results are analyzed as follows: From Table 1, Table 2, Figure 1 and Figure 2It can be seen that the demulsifier of the present invention has a good dehydration effect when used for demulsifying high-sulfur heavy crude oil emulsions, which proves that the furan ring, quaternary ammonium salt, organosilicon, block polyether and molybdenum disulfide nanosheets in the demulsifier structure work together to make the demulsifier easier to dissolve natural emulsifiers such as colloid, asphaltene, solid powder adsorbed on the oil-water interface, prevent the interface film formed by the natural emulsifier from hindering the aggregation of water droplets, and more easily and quickly pass through the outer phase of the emulsion to disperse on the oil-water interface to play a demulsifying effect.

Claims

1. A method for preparing a modified hydrogenated silicon-modified oil polyether demulsifier, characterized in that: The following steps are involved: (1) reacting amino-modified molybdenum disulfide nanosheets and a chain extender in the presence of an etherification catalyst to obtain a nano-modified polyether, wherein the chain extender is ethylene oxide and / or propylene oxide; then reacting the nano-modified polyether with acryloyl chloride to obtain an olefin-modified polyether; the mass ratio of the amino-modified molybdenum disulfide nanosheets to the chain extender is 30:(150-300), and the mass of the acryloyl chloride is 0.2-0.5% of the mass of the nano-modified polyether; (2) reacting an initiator, ethylene oxide and propylene oxide in the presence of an etherification catalyst to obtain a block polyether, and then reacting the block polyether with propenyltrimethoxysilane to obtain an olefin block polyether; the mass ratio of the initiator, ethylene oxide and propylene oxide is 5:(250-350):(100-150); the initiator is composed of diethanolamine and hydrogenated silicone oil in a mass ratio of (2-3):(2-3); (3) Respectively reacting 2,5-furan dimethanol with acryloyl chloride and acyl chloride quaternary ammonium salt to obtain a cationic monomer; the molar ratio of 2,5-furan dimethanol, acryloyl chloride and acyl chloride quaternary ammonium salt is 1:1:1, and the chemical structure of the quaternary ammonium salt is as follows: ; (4) The alkenyl modified polyether, alkenyl block polyether and cationic monomer are polymerized under the action of an initiator to obtain a molybdenum disulfide-hydrogen silicone oil modified polyether composite demulsifier; the mass ratio of the alkenyl modified polyether, the alkenyl block polyether and the cationic monomer is (10-20):(20-30):(40-50); the initiator is composed of ammonium persulfate and a silicon-containing reducing agent, and the chemical structure of the silicon-containing reducing agent is as follows: .

2. The method for preparing the modified hydrogenated silicon-modified oil polyether demulsifier according to claim 1, characterized in that: The amino-modified molybdenum disulfide nanosheet is prepared by reacting molybdenum disulfide nanosheet with gamma-aminopropyltriethoxysilane. The thickness of the molybdenum disulfide nanosheet is 10-20 nm, and the sheet diameter is 200-300 nm.

3. The method for preparing the modified hydrogenated silicon-modified oil polyether demulsifier according to claim 1, characterized in that: The etherification catalyst in step (1) is sodium hydroxide or potassium hydroxide.

4. The method for preparing the modified hydrogenated silicon-modified oil polyether demulsifier according to claim 1 or 3, characterized in that: The temperature of the reaction of the amino-modified molybdenum disulfide nanosheets and the chain extender is 140-150° C. and the pressure is 0.3-0.4 MPa.

5. The method for preparing the modified hydrogenated silicon-modified oil polyether demulsifier according to claim 1, characterized in that: The etherification catalyst in step (2) is sodium hydroxide or potassium hydroxide.

6. The method for preparing the modified hydrogenated silicon-modified oil polyether demulsifier according to claim 1 or 5, characterized in that: The preparation method of the block polyether is as follows: the initiator and propylene oxide are reacted completely under the action of an etherification catalyst at a temperature of 110-120° C. and a pressure of 0.3-0.4 MPa, and then the system after the reaction is reacted with ethylene oxide at a temperature of 125-135° C. and a pressure of 0.3-0.4 MPa to obtain the block polyether; the mass fraction of Si-H groups in the hydrogen-containing silicone oil is 0.4%-0.6%, and the viscosity at 25° C. is 240-400. .

7. The method for preparing the modified hydrogenated silicon-modified oil polyether demulsifier according to claim 1, characterized in that: The reaction temperature of the block polyether and propenyltrimethoxysilane is 80-90°C.

8. The method for preparing the modified hydrogenated silicon-modified oil polyether demulsifier according to claim 1, characterized in that: The mass ratio of the alkenyl modified polyether, alkenyl block polyether, cationic monomer, ammonium persulfate and silicon-containing reducing agent is (10-20):(20-30):(40-50):(0.7-1.2):(5-8).

9. The method for preparing the modified hydrogenated silicon-modified oil polyether demulsifier according to claim 1 or 8, characterized in that: The polymerization reaction time is 3 to 5 hours.

10. A modified hydrogen-containing silicon-modified oil polyether demulsifier prepared by the preparation method of the modified hydrogen-containing silicon-modified oil polyether demulsifier as claimed in claim 1.

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