Clay stabilizer as well as preparation method and application thereof

Abstract

The invention relates to the technical field of oil and gas field exploitation, in particular to a clay stabilizer and a preparation method and application thereof.The clay stabilizer is prepared from, by weight, 1-2 parts of a main agent, 0.5-0.8 part of inorganic nanoparticles, 0.3-0.5 part of sodium metaaluminate, 0.05-0.1 part of ammonium chloride and 80-100 parts of water; wherein the main agent is a compound as shown in a formula (I); the inorganic nanoparticles comprise at least one of silicon dioxide and aluminum oxide; the main agent with a specific structure is matched with the inorganic nanoparticles and the sodium metaaluminate, so that the prepared clay stabilizer not only can prevent clay from expanding and resist scouring, but also can improve high temperature resistance, pressure resistance and antibacterial performance, and can play a role in stabilizing the clay in soil with various pH values.

Description

Technical Field

[0001] The present application relates to the technical field of oil and gas field exploitation, and in particular to a clay stabilizer and a preparation method and application thereof. Background Art

[0002] During the development process of oil field water injection, acidification, fracturing, etc., clay minerals contained in the oil reservoir, such as kaolinite, montmorillonite, illite and chlorite, will hydrate, swell, disperse and migrate when encountering external water or water-based substances, thereby causing blockage of pore channels, reducing formation permeability and causing damage to the reservoir.

[0003] Clay stabilizer is a chemical additive that can inhibit the expansion of stratum clay and the dispersion and migration of clay particles. Clay stabilizers are mainly divided into inorganic salt clay stabilizers and organic polymer clay stabilizers. Inorganic salt clay stabilizers have the advantages of low cost and easy use, but they are not resistant to erosion and have poor timeliness. They can only temporarily stabilize clay and are prone to lose stability when the external environment changes. The Na in stratum water + The ions are exchanged again to the initial water-sensitive state, and because multi-point adsorption similar to polymer cannot be produced, the effect of preventing particle migration is not obvious.

[0004] Organic polymer clay stabilizers are long-lasting and can stabilize clay for a long time. However, for low permeability oil layers, cationic polymers with larger relative molecular weight will increase the damage to the permeability of the oil field. Faced with complex and changeable formation conditions, the use of small and medium molecular weight clay stabilizers is gradually gaining favor among more people.

[0005] However, the existing small and medium molecular weight clay stabilizers have relatively simple functions, mainly focusing on inhibiting clay expansion, but are lacking in temperature and pressure resistance, and cannot function stably in environments with large changes in pH. Summary of the invention

[0006] The present application aims to overcome at least one of the defects of the prior art and provide a clay stabilizer and a preparation method and application thereof. By combining a main agent with a specific structure with inorganic nanoparticles and sodium aluminate, the prepared clay stabilizer can not only prevent clay expansion and scouring resistance, but also improve high temperature resistance, pressure resistance and antibacterial properties, and can stabilize clay in soils of various pH values.

[0007] In a first aspect, the present application provides a clay stabilizer, which is achieved by the following technical solutions:

[0008] A clay stabilizer comprises the following raw materials in parts by weight:

[0009] 1-2 parts of main agent, 0.5-0.8 parts of inorganic nanoparticles, 0.3-0.5 parts of sodium aluminate, 0.05-0.1 parts of ammonium chloride, 80-100 parts of water;

[0010] Wherein, the main agent is a compound represented by formula (I);

[0011] The inorganic nanoparticles include at least one of silicon dioxide and aluminum oxide;

[0012]

[0013] A clay stabilizer according to an embodiment of the present application has at least the following beneficial effects:

[0014] The main agent of the clay stabilizer of the present application has multiple quaternary ammonium salt and quaternary phosphonium salt cationic groups, which can form stronger ionic bonds, thereby maintaining the stability of the structure at high temperatures, and can be more effectively adsorbed on clay particles to prevent the hydration expansion and dispersion of the clay at high temperatures; at the same time, it has multiple longer side chains, which can increase the rigidity and strength of the molecules, so that the stabilizer can better resist deformation and rupture when subjected to pressure, thereby improving the compressive resistance of the clay stabilizer; the introduction of sulfonated groups can enhance the interaction force between molecules, which can significantly improve the temperature resistance of the clay stabilizer, so that it can maintain stable performance in a high temperature environment.

[0015] In the secondary oil recovery technology of oil fields, a large amount of water needs to be reinjected. Since the reinjected water contains sulfate-reducing bacteria, water saprophytes and iron bacteria, it is easy to cause metal corrosion, formation blockage, chemical reagent failure and other problems. The long-term use of quaternary ammonium salt fungicides leads to drug resistance in microorganisms, increased dosage, decreased efficacy, increased costs, and environmental pollution. Quaternary phosphonium salts are a new type of fungicide with a similar structure to quaternary ammonium salts. They have the ability to entangle microorganisms, thereby improving the bactericidal performance. Quaternary phosphonium salts have the advantages of high efficiency, broad spectrum, low toxicity, and easy biodegradability. When combined with quaternary ammonium salts, they can further enhance the ability to bind to soil negative ions, enhance the binding force between clay lattices, crystal layers and particles, and enhance the binding strength.

[0016] The present application introduces inorganic nanoparticles (such as silicon dioxide and aluminum oxide) into a clay stabilizer to form a nanocomposite material. These nanoparticles can increase the rigidity and strength of the stabilizer while improving its high temperature resistance and pressure resistance.

[0017] The sodium aluminate of the present application can ionize aluminate ions, combine with cationic groups or metal cations in water, accelerate flocculation, facilitate the formation of a protective film on the surface of clay, and inhibit the hydration expansion and dispersion migration of clay; at the same time, the addition of sodium aluminate can better adapt to changes in pH value and can stabilize clay in soils of various pH values.

[0018] According to some embodiments of the present application, the average particle size of the inorganic nanoparticles is 50-200 nm.

[0019] According to some embodiments of the present application, the inorganic nanoparticles are silicon dioxide.

[0020] According to some embodiments of the present application, the raw material further comprises 0.02-0.04 parts by weight of a silane coupling agent. The silane coupling agent has good compatibility with the inorganic nanoparticles, and can make the inorganic nanoparticles uniformly dispersed in the clay stabilizer, reduce the agglomeration of the inorganic nanoparticles, thereby improving the role of the inorganic nanoparticles in the clay stabilizer, and increasing the strength, high temperature resistance and pressure resistance of the stabilizer.

[0021] Furthermore, the silane coupling agent includes at least one of methacryloxypropyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, and glycidyloxypropyltrimethoxysilane.

[0022] According to some embodiments of the present application, the preparation of the compound represented by formula (I) comprises the following steps:

[0023] The compound represented by formula (II) is mixed with 1-bromohexane, and a sodium hydroxide solution is added to adjust the pH value to 5-6, and the mixture is reacted to obtain the compound represented by formula (I);

[0024]

[0025] The molar ratio of the compound represented by formula (II) to 1-bromohexane is 1:(4.2-4.8), for example, the molar ratio of the compound represented by formula (II) to 1-bromohexane is 1:4.5.

[0026] Furthermore, the preparation of the compound represented by formula (II) comprises the following steps:

[0027] The compound represented by formula (III) is mixed with sodium 2-aminoethanesulfonate, and acetic acid is used as a catalyst to react to obtain the product;

[0028]

[0029] Wherein, the molar ratio of the compound represented by formula (III) to sodium 2-aminoethanesulfonate is (1.3-1.7):2, for example, the molar ratio of the compound represented by formula (III) to sodium 2-aminoethanesulfonate is 1.5:2;

[0030] The reaction temperature is 110°C-130°C, for example, the reaction temperature is 120°C;

[0031] The reaction time is 72h-168h, for example, the reaction time is 168h;

[0032] The reducing agent for the reaction is sodium cyanoborohydride.

[0033] Furthermore, the preparation of the compound represented by formula (III) comprises the following steps:

[0034] The compound represented by formula (IV) is mixed with triethylphosphine to react to obtain a product;

[0035]

[0036] The molar ratio of the compound represented by formula (IV) to triethyl phosphine is 1:(2.4-2.8), for example, the molar ratio of the compound represented by formula (IV) to triethyl phosphine is 1:2.6.

[0037] In a second aspect, the present application provides a method for preparing the above-mentioned clay stabilizer, which is achieved by the following technical solution:

[0038] A method for preparing a clay stabilizer comprises the following steps:

[0039] (1) Mix the main agent and water according to weight parts, and add ammonium chloride while stirring at a temperature of 30-35°C;

[0040] (2) Raise the temperature to 40-45°C, slowly add sodium aluminate, and stir for 5-10 minutes;

[0041] (3) heating to 45-50° C., adding inorganic nanoparticles, stirring for 20-30 min, and naturally cooling to obtain a clay stabilizer;

[0042] When the raw materials for preparation contain a silane coupling agent, the raw materials added in step (2) also include a silane coupling agent.

[0043] The method for preparing a clay stabilizer according to an embodiment of the present application has at least the following beneficial effects:

[0044] The preparation method of the clay stabilizer of the present application is simple, and the raw materials are sufficiently utilized. By controlling the multi-step addition at different temperatures, the raw materials can be mixed more evenly, which facilitates the matching of the main agent of the clay stabilizer with the auxiliary agents, and fully exerts the effect of preventing expansion and preventing the dispersion and migration of clay particles, which helps to reduce production costs and improve economic benefits.

[0045] According to some embodiments of the present application, the stirring speed in step (2) is 2000-4000 r / min.

[0046] According to some embodiments of the present application, the stirring speed in step (3) is 2000-4000 r / min.

[0047] In a third aspect, the embodiments of the present application provide the use of the above-mentioned clay stabilizer in oil field water injection, acidification, and fracturing. DETAILED DESCRIPTION

[0048] To make the purpose, technical solution and advantages of the present application clearer, the following will be further described in detail in conjunction with specific embodiments. The embodiments described here are only part of the embodiments of the present application and cannot be understood as limiting the scope of protection of the present application.

[0049] Example 1

[0050] Preparation of clay stabilizer: Select raw materials according to weight: 1.5 parts of main agent, 0.7 parts of inorganic nanoparticles, 0.4 parts of sodium aluminate, 0.08 parts of ammonium chloride, 0.03 parts of silane coupling agent, 90 parts of water; wherein, the inorganic nanoparticles are silicon dioxide with an average particle size of 100 nm; the silane coupling agent is selected from KH-570 of Hubei Wuda Organic Silicon New Materials Co., Ltd.;

[0051] (1) Mix the main agent and water according to weight parts, and add ammonium chloride while stirring at 33°C;

[0052] (2) Raise the temperature to 42°C, slowly add sodium aluminate and silane coupling agent, and stir at a speed of 3000 r / min for 8 min;

[0053] (3) heating to 48° C., adding inorganic nanoparticles, stirring at a speed of 3000 r / min for 25 min, and naturally cooling to obtain a clay stabilizer;

[0054] Wherein, the preparation of the main agent comprises the following steps:

[0055] S1. 2 mol of the compound represented by formula (Ⅳ) and 0.02 mol of acetonitrile are placed in a three-necked flask, and then 5.2 mol of triethylphosphine is added and refluxed with stirring. Nitrogen is used for protection during the reaction. After the reaction is completed, N,N-dimethylformamide is used for washing several times, and vacuum filtration is performed under nitrogen protection. Finally, the obtained product is placed in a vacuum drying oven and dried at 50° C. to obtain a compound represented by formula (Ⅲ);

[0056] S2. 1.5 mol of the compound represented by formula (III), 2 mol of sodium 2-aminoethanesulfonate, and 1 mL of a solvent prepared by mixing o-dichlorobenzene and n-butanol in a volume ratio of 9:1 were mixed, and ultrasonically mixed for 3 minutes to make them uniform. Then, 0.1 mL of 6 mol / L acetic acid was added as a catalyst, and the mixture was heated at 120° C. for 168 h under a nitrogen protective gas atmosphere. A reducing agent, sodium cyanoborohydride, was added to react for 9 h. The reaction solution was vacuum filtered, and repeatedly washed with N,N-dimethylformamide and dichloromethane to obtain a compound represented by formula (II);

[0057] S3. Mix 2 mol of the compound represented by formula (II), 9 mol of 1-bromohexane and 2 mL of ethanol, add sodium hydroxide solution to adjust the pH value to 5-6, and react at 80°C for 36 hours under a nitrogen protective gas atmosphere to obtain the main agent.

[0058] Example 2

[0059] Preparation of clay stabilizer: Select raw materials by weight: 2 parts of main agent, 0.5 parts of inorganic nanoparticles, 0.5 parts of sodium aluminate, 0.05 parts of ammonium chloride, 0.04 parts of silane coupling agent, 80 parts of water; wherein, the inorganic nanoparticles are aluminum oxide with an average particle size of 200nm; the silane coupling agent is selected from KH-570 of Hubei Wuda Organic Silicon New Materials Co., Ltd.;

[0060] (1) Mix the main agent and water according to weight parts, and add ammonium chloride while stirring at 30°C;

[0061] (2) Raise the temperature to 45°C, slowly add sodium aluminate and silane coupling agent, and stir at a speed of 2000 r / min for 10 min;

[0062] (3) heating to 50° C., adding inorganic nanoparticles, stirring at a speed of 4000 r / min for 20 min, and naturally cooling to obtain a clay stabilizer;

[0063] Wherein, the preparation of the main agent comprises the following steps:

[0064] S1. 2 mol of the compound represented by formula (Ⅳ) and 0.02 mol of acetonitrile are placed in a three-necked flask, and then 5.6 mol of triethylphosphine is added and refluxed with stirring. Nitrogen is used for protection during the reaction. After the reaction is completed, N,N-dimethylformamide is used for washing several times, and vacuum filtration is performed under nitrogen protection. Finally, the obtained product is placed in a vacuum drying oven and dried at 60° C. to obtain a compound represented by formula (Ⅲ);

[0065] S2. 1.3 mol of the compound represented by formula (III), 2 mol of sodium 2-aminoethanesulfonate, and 1 mL of a solvent prepared by mixing o-dichlorobenzene and n-butanol in a volume ratio of 8:1 were mixed, and ultrasonically mixed for 3 minutes to make them uniform. Then, 0.1 mL of 6 mol / L acetic acid was added as a catalyst, and the mixture was heated at 130° C. for 72 h under a nitrogen protective gas atmosphere. A reducing agent, sodium cyanoborohydride, was added to react for 10 h. The reaction solution was vacuum filtered, and repeatedly washed with N,N-dimethylformamide and dichloromethane to obtain a compound represented by formula (II);

[0066] S3. Mix 2 mol of the compound represented by formula (II), 8.4 mol of 1-bromohexane and 2 mL of ethanol, add sodium hydroxide solution to adjust the pH value to 5-6, and react at 80°C for 36 hours under a nitrogen protective gas atmosphere to obtain the main agent.

[0067] Example 3

[0068] Preparation of clay stabilizer: Select raw materials according to weight: 1 part of main agent, 0.8 parts of inorganic nanoparticles, 0.3 parts of sodium aluminate, 0.1 parts of ammonium chloride, 0.02 parts of silane coupling agent, 100 parts of water; wherein, the inorganic nanoparticles are silicon dioxide with an average particle size of 50nm; the silane coupling agent is selected from KH-570 of Hubei Wuda Organic Silicon New Materials Co., Ltd.;

[0069] (1) Mix the main agent and water according to weight parts, and add ammonium chloride while stirring at 35°C;

[0070] (2) Raise the temperature to 40°C, slowly add sodium aluminate and silane coupling agent, and stir at a speed of 4000 r / min for 5 min;

[0071] (3) heating to 45° C., adding inorganic nanoparticles, stirring at a speed of 2000 r / min for 30 min, and naturally cooling to obtain a clay stabilizer;

[0072] Wherein, the preparation of the main agent comprises the following steps:

[0073] S1. 2 mol of the compound represented by formula (Ⅳ) and 0.02 mol of acetonitrile are placed in a three-necked flask, and then 4.8 mol of triethylphosphine is added and refluxed with stirring. Nitrogen is used for protection during the reaction. After the reaction is completed, N,N-dimethylformamide is used for washing several times, and vacuum filtration is performed under nitrogen protection. Finally, the obtained product is placed in a vacuum drying oven and dried at 45°C to obtain a compound represented by formula (Ⅲ);

[0074] S2. 1.7 mol of the compound represented by formula (III), 2 mol of sodium 2-aminoethanesulfonate, and 1 mL of a solvent prepared by mixing o-dichlorobenzene and n-butanol in a volume ratio of 10:1 were mixed, and the mixture was uniformly mixed by ultrasonic treatment for 3 minutes, and 0.1 mL of 6 mol / L acetic acid was added as a catalyst, and the mixture was heated at 110° C. for 120 h under a nitrogen protective gas atmosphere, and sodium cyanoborohydride as a reducing agent was added to react for 8 h. The reaction solution was vacuum filtered, and repeatedly washed with N,N-dimethylformamide and dichloromethane to obtain the compound represented by formula (II);

[0075] S3. Mix 2 mol of the compound represented by formula (II), 9.6 mol of 1-bromohexane and 2 mL of ethanol, add sodium hydroxide solution to adjust the pH value to 5-6, and react at 80°C for 36 hours under a nitrogen protective gas atmosphere to obtain the main agent.

[0076] Example 4

[0077] Preparation of clay stabilizer: Select raw materials according to weight: 1.6 parts of main agent, 0.6 parts of inorganic nanoparticles, 0.4 parts of sodium aluminate, 0.06 parts of ammonium chloride, 0.03 parts of silane coupling agent, 85 parts of water; wherein, the inorganic nanoparticles are silicon dioxide with an average particle size of 80nm; the silane coupling agent is selected from KH-570 of Hubei Wuda Organic Silicon New Materials Co., Ltd.;

[0078] (1) Mix the main agent and water according to weight parts, and add ammonium chloride while stirring at 32°C;

[0079] (2) Raise the temperature to 42°C, slowly add sodium aluminate and silane coupling agent, and stir at a speed of 3000 r / min for 7 min;

[0080] (3) heating to 49° C., adding inorganic nanoparticles, stirring at a speed of 3000 r / min for 28 min, and naturally cooling to obtain a clay stabilizer;

[0081] Wherein, the preparation of the main agent comprises the following steps:

[0082] S1. 2 mol of the compound represented by formula (Ⅳ) and 0.02 mol of acetonitrile are placed in a three-necked flask, and then 5.4 mol of triethylphosphine is added and refluxed with stirring. Nitrogen is used for protection during the reaction. After the reaction is completed, N,N-dimethylformamide is used for washing several times, and vacuum filtration is performed under nitrogen protection. Finally, the obtained product is placed in a vacuum drying oven and dried at 50° C. to obtain a compound represented by formula (Ⅲ);

[0083] S2. 1.6 mol of the compound represented by formula (III), 2 mol of sodium 2-aminoethanesulfonate, and 1 mL of a solvent prepared by mixing o-dichlorobenzene and n-butanol in a volume ratio of 9:1 were mixed, and ultrasonically mixed for 3 minutes to make them uniform. Then, 0.1 mL of 6 mol / L acetic acid was added as a catalyst, and the mixture was heated at 120° C. for 144 h under a nitrogen protective gas atmosphere. A reducing agent, sodium cyanoborohydride, was added to react for 9 h. The reaction solution was vacuum filtered, and repeatedly washed with N,N-dimethylformamide and dichloromethane to obtain a compound represented by formula (II);

[0084] S3. Mix 2 mol of the compound represented by formula (II), 9 mol of 1-bromohexane and 2 mL of ethanol, add sodium hydroxide solution to adjust the pH value to 5-6, and react at 80°C for 36 hours under a nitrogen protective gas atmosphere to obtain the main agent.

[0085] Comparative Example 1

[0086] Preparation of clay stabilizer: Select raw materials according to weight: 1.5 parts of main agent, 0.7 parts of inorganic nanoparticles, 0.4 parts of sodium aluminate, 0.08 parts of ammonium chloride, 0.03 parts of silane coupling agent, 90 parts of water; wherein, the inorganic nanoparticles are silicon dioxide with an average particle size of 100 nm; the silane coupling agent is selected from KH-570 of Hubei Wuda Organic Silicon New Materials Co., Ltd.;

[0087] (1) Mix the main agent and water according to weight parts, and add ammonium chloride while stirring at 33°C;

[0088] (2) Raise the temperature to 42°C, slowly add sodium aluminate and silane coupling agent, and stir at a speed of 3000 r / min for 8 min;

[0089] (3) heating to 48° C., adding inorganic nanoparticles, stirring at a speed of 3000 r / min for 25 min, and naturally cooling to obtain a clay stabilizer;

[0090] Wherein, the preparation of the main agent comprises the following steps:

[0091] S1. 2 mol of the compound represented by formula (Ⅳ) and 0.02 mol of acetonitrile are placed in a three-necked flask, and then 5.2 mol of triethylphosphine is added and refluxed with stirring. Nitrogen is used for protection during the reaction. After the reaction is completed, N,N-dimethylformamide is used for washing several times, and vacuum filtration is performed under nitrogen protection. Finally, the obtained product is placed in a vacuum drying oven and dried at 50° C. to obtain a compound represented by formula (Ⅲ);

[0092] S2. 1.5 mol of the compound represented by formula (III), 2 mol of aminoethane, and 1 mL of a solvent prepared by mixing o-dichlorobenzene and n-butanol in a volume ratio of 9:1 were mixed, and after being uniformly mixed by ultrasonication for 3 minutes, 0.1 mL of 6 mol / L acetic acid was added as a catalyst, and the mixture was heated at 120° C. for 168 h under a nitrogen protective gas atmosphere, and sodium cyanoborohydride as a reducing agent was added to react for 9 h. The reaction solution was vacuum filtered, and repeatedly washed with N,N-dimethylformamide and dichloromethane to obtain a compound having a structure similar to that of the compound represented by formula (II) but without a sulfonic acid group;

[0093] S3. Mix 2 mol of a compound having a structure similar to that of the compound shown in formula (II) but not containing a sulfonic acid group, 9 mol of 1-bromohexane, and 2 mL of ethanol, add sodium hydroxide solution to adjust the pH value to 5-6, and react at 80°C for 36 hours under a nitrogen protective gas atmosphere to obtain the main agent.

[0094] Comparative Example 2

[0095] Preparation of clay stabilizer: Select raw materials by weight: 1.5 parts of main agent, 0.7 parts of inorganic nanoparticles, 0.08 parts of ammonium chloride, 0.03 parts of silane coupling agent, and 90 parts of water; wherein the inorganic nanoparticles are silicon dioxide with an average particle size of 100 nm; the silane coupling agent is selected from KH-570 of Hubei Wuda Organic Silicon New Materials Co., Ltd.;

[0096] (1) Mix the main agent and water according to weight parts, and add ammonium chloride while stirring at 33°C;

[0097] (2) Raise the temperature to 42°C, slowly add the silane coupling agent, and stir at a speed of 3000 r / min for 8 min;

[0098] (3) heating to 48° C., adding inorganic nanoparticles, stirring at a speed of 3000 r / min for 25 min, and naturally cooling to obtain a clay stabilizer;

[0099] Wherein, the preparation of the main agent comprises the following steps:

[0100] S1. 2 mol of the compound represented by formula (Ⅳ) and 0.02 mol of acetonitrile are placed in a three-necked flask, and then 5.2 mol of triethylphosphine is added and refluxed with stirring. Nitrogen is used for protection during the reaction. After the reaction is completed, N,N-dimethylformamide is used for washing several times, and vacuum filtration is performed under nitrogen protection. Finally, the obtained product is placed in a vacuum drying oven and dried at 50° C. to obtain a compound represented by formula (Ⅲ);

[0101] S2. 1.5 mol of the compound represented by formula (III), 2 mol of sodium 2-aminoethanesulfonate, and 1 mL of a solvent prepared by mixing o-dichlorobenzene and n-butanol in a volume ratio of 9:1 were mixed, and ultrasonically mixed for 3 minutes to make them uniform. Then, 0.1 mL of 6 mol / L acetic acid was added as a catalyst, and the mixture was heated at 120° C. for 168 h under a nitrogen protective gas atmosphere. A reducing agent, sodium cyanoborohydride, was added to react for 9 h. The reaction solution was vacuum filtered, and repeatedly washed with N,N-dimethylformamide and dichloromethane to obtain a compound represented by formula (II);

[0102] S3. Mix 2 mol of the compound represented by formula (II), 9 mol of 1-bromohexane and 2 mL of ethanol, add sodium hydroxide solution to adjust the pH value to 5-6, and react at 80°C for 36 hours under a nitrogen protective gas atmosphere to obtain the main agent.

[0103] Comparative Example 3

[0104] Preparation of clay stabilizer: Select raw materials according to weight: 1.5 parts of main agent, 0.4 parts of sodium aluminate, 0.08 parts of ammonium chloride, and 90 parts of water;

[0105] (1) Mix the main agent and water according to weight parts, and add ammonium chloride while stirring at 33°C;

[0106] (2) heating to 42° C., slowly adding sodium aluminate, stirring at a speed of 3000 r / min for 8 min, and naturally cooling to obtain a clay stabilizer;

[0107] Wherein, the preparation of the main agent comprises the following steps:

[0108] S1. 2 mol of the compound represented by formula (Ⅳ) and 0.02 mol of acetonitrile are placed in a three-necked flask, and then 5.2 mol of triethylphosphine is added and refluxed with stirring. Nitrogen is used for protection during the reaction. After the reaction is completed, N,N-dimethylformamide is used for washing several times, and vacuum filtration is performed under nitrogen protection. Finally, the obtained product is placed in a vacuum drying oven and dried at 50° C. to obtain a compound represented by formula (Ⅲ);

[0109] S2. 1.5 mol of the compound represented by formula (III), 2 mol of sodium 2-aminoethanesulfonate, and 1 mL of a solvent prepared by mixing o-dichlorobenzene and n-butanol in a volume ratio of 9:1 were mixed, and ultrasonically mixed for 3 minutes to make them uniform. Then, 0.1 mL of 6 mol / L acetic acid was added as a catalyst, and the mixture was heated at 120° C. for 168 h under a nitrogen protective gas atmosphere. A reducing agent, sodium cyanoborohydride, was added to react for 9 h. The reaction solution was vacuum filtered, and repeatedly washed with N,N-dimethylformamide and dichloromethane to obtain a compound represented by formula (II);

[0110] S3. Mix 2 mol of the compound represented by formula (II), 9 mol of 1-bromohexane and 2 mL of ethanol, add sodium hydroxide solution to adjust the pH value to 5-6, and react at 80°C for 36 hours under a nitrogen protective gas atmosphere to obtain the main agent.

[0111] Comparative Example 4

[0112] Preparation of clay stabilizer: Select raw materials according to weight: 1.5 parts of main agent, 0.7 parts of inorganic nanoparticles, 0.4 parts of sodium aluminate, 0.08 parts of ammonium chloride, and 90 parts of water; wherein the inorganic nanoparticles are silicon dioxide with an average particle size of 100 nm;

[0113] (1) Mix the main agent and water according to weight parts, and add ammonium chloride while stirring at 33°C;

[0114] (2) Raise the temperature to 42°C, slowly add sodium aluminate, and stir at a speed of 3000 r / min for 8 min;

[0115] (3) heating to 48° C., adding inorganic nanoparticles, stirring at a speed of 3000 r / min for 25 min, and naturally cooling to obtain a clay stabilizer;

[0116] Wherein, the preparation of the main agent comprises the following steps:

[0117] S1. 2 mol of the compound represented by formula (Ⅳ) and 0.02 mol of acetonitrile are placed in a three-necked flask, and then 5.2 mol of triethylphosphine is added and refluxed with stirring. Nitrogen is used for protection during the reaction. After the reaction is completed, N,N-dimethylformamide is used for washing several times, and vacuum filtration is performed under nitrogen protection. Finally, the obtained product is placed in a vacuum drying oven and dried at 50° C. to obtain a compound represented by formula (Ⅲ);

[0118] S2. 1.5 mol of the compound represented by formula (III), 2 mol of sodium 2-aminoethanesulfonate, and 1 mL of a solvent prepared by mixing o-dichlorobenzene and n-butanol in a volume ratio of 9:1 were mixed, and ultrasonically mixed for 3 minutes to make them uniform. Then, 0.1 mL of 6 mol / L acetic acid was added as a catalyst, and the mixture was heated at 120° C. for 168 h under a nitrogen protective gas atmosphere. A reducing agent, sodium cyanoborohydride, was added to react for 9 h. The reaction solution was vacuum filtered, and repeatedly washed with N,N-dimethylformamide and dichloromethane to obtain a compound represented by formula (II);

[0119] S3. Mix 2 mol of the compound represented by formula (II), 9 mol of 1-bromohexane and 2 mL of ethanol, add sodium hydroxide solution to adjust the pH value to 5-6, and react at 80°C for 36 hours under a nitrogen protective gas atmosphere to obtain the main agent.

[0120] Experimental example

[0121] The clay stabilizers prepared in Examples 1-4 and Comparative Examples 1-4 were tested for anti-swelling rate, water washing resistance, and temperature resistance, respectively, and the test methods were as follows:

[0122] The anti-swelling rate is tested according to the standard of Q / SH10201966-2013.

[0123] The water washability is tested according to the standard of Q / SH10201966-2013.

[0124] The temperature resistance test is to seal the clay stabilizer solution into a constant temperature box set at different temperatures, take it out after 24 hours, and test the anti-swelling rate according to the above-mentioned anti-swelling rate test method. As the temperature rises, the anti-swelling rate gradually decreases. When the anti-swelling rate drops to 85%, the corresponding temperature is recorded as the temperature resistance temperature of the clay stabilizer.

[0125] The test data is shown in Table 1 below:

[0126] Table 1

[0127]

[0128] It can be seen from Table 1 that the clay stabilizers prepared in Examples 1-4 of the present application have high anti-swelling rate and water washability, and good temperature resistance.

[0129] The main agent of Comparative Example 1 does not contain a sulfonic acid group, and the rest is the same as Example 1. The anti-swelling rate and water washing resistance of the clay stabilizer prepared in Comparative Example 1 are slightly worse, and the temperature resistance is significantly reduced, indicating that the introduction of sulfonated groups in this application can enhance the interaction between molecules and significantly improve the temperature resistance of the clay stabilizer, so that it can maintain stable performance in a high temperature environment.

[0130] The preparation raw materials of Comparative Example 2 do not contain sodium aluminate, and the rest are the same as Example 1. The anti-swelling rate and water washing resistance of the clay stabilizer prepared in Comparative Example 2 are significantly deteriorated, and the temperature resistance is also slightly reduced, indicating that the sodium aluminate of the present application can ionize aluminate ions, combine with cationic groups or metal cations in water, accelerate flocculation, facilitate the formation of a protective film on the clay surface, and inhibit the hydration expansion and dispersion migration of the clay.

[0131] The preparation raw materials of Comparative Example 3 do not contain inorganic nanoparticles and silane coupling agent, and the rest are the same as Example 1. The anti-swelling rate and water washing resistance of the clay stabilizer prepared in Comparative Example 3 are significantly deteriorated, and the temperature resistance is also significantly reduced, indicating that the present application introduces inorganic nanoparticles (such as silica, alumina) into the clay stabilizer to form a nano-composite material. These nanoparticles can increase the rigidity and strength of the stabilizer, while improving its high temperature resistance and pressure resistance.

[0132] The preparation raw materials of Comparative Example 4 do not contain silane coupling agent, and the rest are the same as Example 1. The anti-swelling rate and water wash resistance of the clay stabilizer prepared in Comparative Example 4 deteriorate, and the temperature resistance also decreases slightly, indicating that the silane coupling agent of the present application has good compatibility with the inorganic nanoparticles, and can make the inorganic nanoparticles evenly dispersed in the clay stabilizer, reduce the agglomeration of the inorganic nanoparticles, thereby improving the role of the inorganic nanoparticles in the clay stabilizer, and increasing the strength, high temperature resistance and pressure resistance of the stabilizer.

[0133] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions or variations may be made to the embodiments without departing from the principles and purpose of the present application, and that the technical solutions after these changes, modifications, substitutions or variations will fall within the scope of protection of the present application.

Claims

1. A clay stabilizer comprising the following raw materials in parts by weight: 1-2 parts of main agent, 0.5-0.8 parts of inorganic nanoparticles, 0.3-0.5 parts of sodium aluminate, 0.05-0.1 parts of ammonium chloride, 80-100 parts of water; in, The main agent is a compound represented by formula (I); The inorganic nanoparticles include at least one of silicon dioxide and aluminum oxide; 2. A clay stabilizer according to claim 1, characterized in that: The average particle size of the inorganic nanoparticles is 50-200 nm.

3. A clay stabilizer according to claim 1, characterized in that: The preparation raw materials also include 0.02-0.04 parts by weight of a silane coupling agent.

4. A clay stabilizer according to claim 3, characterized in that: The silane coupling agent includes at least one of methacryloxypropyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane and glycidyloxypropyltrimethoxysilane.

5. A clay stabilizer according to claim 1, characterized in that: The preparation of the compound represented by formula (I) comprises the following steps: The compound represented by formula (II) is mixed with 1-bromohexane, and a sodium hydroxide solution is added to adjust the pH value to 5-6, and the mixture is reacted to obtain the compound represented by formula (I); 6. A clay stabilizer according to claim 5, characterized in that: The preparation of the compound represented by formula (II) comprises the following steps: The compound represented by formula (III) is mixed with sodium 2-aminoethanesulfonate, and acetic acid is used as a catalyst to react to obtain the product; 7. A clay stabilizer according to claim 6, characterized in that: The preparation of the compound represented by formula (III) comprises the following steps: The compound represented by formula (IV) is mixed with triethylphosphine to react to obtain a product; 8. A method for preparing a clay stabilizer according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) Mix the main agent and water according to weight parts, and add ammonium chloride while stirring at a temperature of 30-35°C; (2) Raise the temperature to 40-45°C, slowly add sodium aluminate, and stir for 5-10 minutes; (3) heating to 45-50° C., adding inorganic nanoparticles, stirring for 20-30 min, and naturally cooling to obtain a clay stabilizer; When the raw materials for preparation contain a silane coupling agent, the raw materials added in step (2) also include a silane coupling agent.

9. The method for preparing a clay stabilizer according to claim 8, characterized in that: The stirring speed in step (2) is 2000-4000 r / min, and / or the stirring speed in step (3) is 2000-4000 r / min.

10. Use of the clay stabilizer according to any one of claims 1 to 7 in oil field water injection, acidification and fracturing.

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