Temperature-resistant salt-resistant efficient gel as well as preparation method and application thereof

Abstract

The invention relates to the field of oil exploitation, in particular to temperature-resistant and salt-resistant efficient gel as well as a preparation method and application thereof, which are used for solving the problems that the efficiency of the gel is influenced and the oil displacement effect is reduced due to poor high temperature resistance and salt resistance and easiness in failure of the existing polyacrylamide hydrogel. According to the preparation method, through a copolymerization technology, various monomers with excellent temperature resistance and salt resistance, such as acrylamide, methacryloyloxyethyl trimethyl ammonium chloride, 2-acrylamido-2-methylpropanesulfonic acid, a temperature-resistant monomer and a hydrophobic macromonomer, are integrated, so that the gel can bear a relatively high temperature without degradation or performance reduction; the prepared oil displacement gel has good stability in a high-salinity environment, does not lose an oil displacement effect due to the existence of salt, ensures the activity and stability of the gel in a high-temperature and high-salt-content oil reservoir environment, and obviously enhances the oil displacement efficiency of the gel in crude oil exploitation, thereby greatly improving the exploitation efficiency and recovery rate of crude oil.

Description

Technical Field

[0001] The present invention relates to the field of oil exploitation, and particularly to a high-temperature and salt-resistant efficient gel, a preparation method thereof, and a use thereof. Background Art

[0002] As a kind of high-efficient water-soluble polymer compound, polyacrylamide has been widely used in oilfield exploitation and other fields due to its good performance in regulating the viscosity of aqueous solution. With the increasing shortage of global oil resources, improving oil exploitation efficiency and crude oil recovery rate has become one of the urgent problems to be solved at present. In conventional crude oil exploitation, with the increase of exploitation depth, the formation temperature gradually rises. Traditional polyacrylamide hydrogels have poor stability in high-temperature environments, are prone to degradation in high-temperature environments, and it is difficult to meet the requirements of deep well exploitation. In addition, the high salinity brine in the formation can cause the gel to hydrolyze or the polymerization structure to be damaged, thus affecting the efficacy of the gel and reducing the oil displacement effect. Therefore, developing a high-temperature and salt-resistant efficient gel that can work stably in high-temperature and high-salinity salt environments and a preparation method thereof is of great significance for improving crude oil recovery rate. Summary of the Invention

[0003] In order to overcome the above technical problems, the purpose of the present invention is to provide a high-temperature and salt-resistant efficient gel, a preparation method thereof, and a use thereof, which solve the problems that the existing polyacrylamide hydrogels have poor high-temperature resistance and salt resistance, are prone to failure, and thus affect the efficacy of the gel and reduce the oil displacement effect.

[0004] The purpose of the present invention can be achieved by the following technical solutions:

[0005] A preparation method of a high-temperature and salt-resistant efficient gel, comprising the following steps:

[0006] Step 1: Add methacrylic acid and dichloromethane into a three-necked flask equipped with a stirrer, a thermometer, and a constant-pressure dropping funnel, stir and react for 20 - 30 min under the conditions of a temperature of 0 - 10°C and a stirring rate of 300 - 400 r / min. Then, while stirring, gradually dropwise add thionyl chloride solution, control the dropping rate to be 1 - 2 drops / s. After the dropping is completed, continue to stir and react for 20 - 30 min. Then, raise the temperature to 35 - 40°C and continue to stir and react for 8 - 10 h. After the reaction is completed, cool the reaction product to room temperature, and then rotate and evaporate to remove the solvent to obtain Intermediate 1;

[0007] Step 2: Add 1-naphthylamine and anhydrous ether into a three-necked flask equipped with a stirrer, a thermometer, a gas guide tube and a constant pressure dropping funnel. Introduce nitrogen for protection. Stir and react for 20 - 30 min under the conditions of a temperature of 25 - 30 °C and a stirring rate of 300 - 400 r / min. Then, while stirring, gradually add hexadecyl bromide dropwise under the condition of heating to 80 - 85 °C, controlling the dropping rate at 1 - 2 drops / s. After the dropping is completed, continue to stir and react for 8 - 10 h. After the reaction is completed, cool the reaction product to room temperature, then add it to the sodium hydroxide solution, and then perform vacuum filtration. Rotate and evaporate the filtrate to remove the solvent, and then recrystallize with dichloromethane to obtain Intermediate 2;

[0008] Step 3: Add Intermediate 2 and dichloromethane into a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel. Stir and react for 20 - 30 min under the conditions of a temperature of -5 - 0 °C and a stirring rate of 300 - 400 r / min. Then, while stirring, gradually add the Intermediate 1 solution dropwise, controlling the dropping rate at 1 - 2 drops / s. After the dropping is completed, continue to stir and react for 20 - 30 min. Then, continue to stir and react for 6 - 7 h under the condition of heating to 25 - 30 °C. After the reaction is completed, wash the reaction product successively with saturated sodium carbonate solution and distilled water 2 - 3 times, then dry it with anhydrous magnesium sulfate, then perform vacuum filtration. Rotate and evaporate the filtrate to remove the solvent to obtain the temperature-resistant monomer;

[0009] Step 4: Add isophorone diisocyanate, dibutyltin dilaurate and anhydrous acetone into a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel. Stir and react for 20 - 30 min under the conditions of a temperature of 25 - 30 °C and a stirring rate of 300 - 400 r / min. Then, while stirring, gradually add 1,1,1,2,2,3,3,4,4,5,5,6,6-tridecafluoro-1-hexanol dropwise, controlling the dropping rate at 1 - 2 drops / s. After the dropping is completed, heat to 80 - 85 °C and continue to stir and react for 2 - 3 h. After the reaction is completed, cool the reaction product to room temperature, then add it to petroleum ether, and then perform vacuum filtration. Place the filter cake in a vacuum drying oven and dry it at a temperature of 55 - 60 °C for 2 - 3 h to obtain Intermediate 3;

[0010] Step 5: Add Intermediate 3 and anhydrous acetone into a three-necked flask equipped with a stirrer and a thermometer. Stir and react for 20 - 30 min under the conditions of a temperature of 25 - 30 °C and a stirring rate of 300 - 400 r / min. Then, add the vinyl macromonomer and heat to 40 - 45 °C and continue to stir and react for 7 - 8 h. After the reaction is completed, cool the reaction product to room temperature, then add it to petroleum ether, and then perform vacuum filtration. Place the filter cake in a vacuum drying oven and dry it at a temperature of 40 - 45 °C for 2 - 3 h to obtain the hydrophobic macromonomer;

[0011] Step 6: Add acrylamide, methacryloyloxyethyl trimethyl ammonium chloride, 2-acrylamido-2-methylpropanesulfonic acid, temperature-resistant monomer, hydrophobic macromonomer, surfactant and deionized water into a three-necked flask equipped with a stirrer, a thermometer and a gas pipe. Introduce nitrogen for protection. Stir and react for 20 - 30 min under the conditions of a temperature of 25 - 30 °C and a stirring rate of 300 - 400 r / min. Then adjust the pH to 7 - 9 with sodium hydroxide solution. After that, add persulfate and continue to stir and react for 8 - 36 h under the condition of heating to 35 - 75 °C. After the reaction is completed, cool the reaction product to room temperature, and then add distilled water to adjust the copolymer concentration to 0.1 - 4 g / L to obtain a copolymer solution;

[0012] Step 7: Add the copolymer solution, crosslinking agent and heat stabilizer into a three-necked flask equipped with a stirrer, a thermometer and a gas pipe. Introduce nitrogen for protection. Stir and react for 2 - 3 h under the conditions of a temperature of 25 - 30 °C and a stirring rate of 300 - 400 r / min to obtain a temperature-resistant and salt-resistant high-efficiency gel.

[0013] As a further scheme of the present invention: The dosage ratio of the methacrylic acid, dichloromethane and thionyl chloride solution in Step 1 is 10 mmol: 20 - 25 mL: 15 - 18 mL.

[0014] As a further scheme of the present invention: The thionyl chloride solution in Step 1 is a solution formed by dissolving thionyl chloride in dichloromethane according to 10 - 12 mmol: 15 mL.

[0015] As a further scheme of the present invention: The dosage ratio of the 1-naphthylamine, anhydrous ether and 1-bromohexadecane in Step 2 is 10 mmol: 40 - 50 mL: 10 mmol.

[0016] As a further scheme of the present invention: The mass fraction of the sodium hydroxide solution in Step 2 is 8 - 10%.

[0017] As a further scheme of the present invention: The dosage ratio of the intermediate 2, dichloromethane and the intermediate 1 solution in Step 3 is 10 mmol: 20 - 25 mL: 20 - 25 mL.

[0018] As a further scheme of the present invention: The intermediate 1 solution in Step 3 is a solution formed by dissolving intermediate 1 in dichloromethane according to 11 - 13 mmol: 20 mL.

[0019] As a further scheme of the present invention: The dosage ratio of the isophorone diisocyanate, dibutyltin dilaurate, anhydrous acetone and dodecafluoroheptanol in Step 4 is 11 - 12 mmol: 0.04 - 0.06 g: 50 - 55 mL: 10 mmol.

[0020] As a further solution of the present invention: the dosage ratio of the intermediate 3, anhydrous acetone and vinyl macromonomer in step five is 10 mmol: 70 - 80 mL: 11 - 13 mmol.

[0021] As a further solution of the present invention: the vinyl macromonomer in step five is one of APEG - 2400, HPEG - 2400 and EPEG - 3000.

[0022] As a further solution of the present invention: the dosage ratio of acrylamide, methylacryloyloxyethyl trimethyl ammonium chloride, 2 - acrylamido - 2 - methylpropane sulfonic acid, temperature - resistant monomer, hydrophobic macromonomer, surfactant, deionized water and persulfate in step six is 20 g: 1 - 20 g: 1 - 20 g: 0.05 - 10 g: 0.1 - 15 g: 0.05 - 5 g: 60 - 100 g: 0.002 - 1 g.

[0023] As a further solution of the present invention: the surfactant in step six is one of sodium dodecyl sulfate and sodium dodecyl benzene sulfonate; the persulfate is one of potassium persulfate and ammonium persulfate; the mass fraction of the sodium hydroxide solution is 10 - 15%.

[0024] As a further solution of the present invention: the dosage ratio of the copolymer solution, cross - linker and heat stabilizer in step seven is 1000 mL: 0.01 - 1 g: 0.005 - 1 g.

[0025] As a further solution of the present invention: the cross - linker in step seven is one of glyoxal and glutaraldehyde; the heat stabilizer is sodium sulfite.

[0026] As a further solution of the present invention: the temperature - resistant and salt - resistant high - efficiency gel is prepared according to the preparation method of the temperature - resistant and salt - resistant high - efficiency gel.

[0027] As a further solution of the present invention: the use of the temperature - resistant and salt - resistant high - efficiency gel prepared according to the preparation method of the temperature - resistant and salt - resistant high - efficiency gel in the field of oil exploitation.

[0028] The beneficial effects of the present invention:

[0029] A temperature-resistant and salt-resistant high-efficiency gel, its preparation method and use according to the present invention. Through the reaction of methacrylic acid and thionyl dichloride, the carboxyl group on methacrylic acid is transformed into an acyl chloride group to obtain intermediate 1. Then, 1-naphthylamine and 1-bromohexadecane react, and the amino group on 1-naphthylamine reacts with the bromine atom on 1-bromohexadecane, -NH2 is transformed into -NH-, and at the same time a long carbon chain is introduced to obtain intermediate 2. Then, intermediate 1 and intermediate 2 react, and the acyl chloride group on intermediate 1 reacts with -NH- on intermediate 2, and at the same time an alkenyl group is introduced to obtain a temperature-resistant monomer. Then, isophorone diisocyanate and dodecafluoroheptanol react, and one isocyanate group on isophorone diisocyanate reacts with the hydroxyl group on dodecafluoroheptanol to introduce a large number of C-F bonds to obtain intermediate 3. Then, intermediate 3 and the alkenyl macromonomer react, and the isocyanate group on intermediate 3 reacts with the hydroxyl group on the alkenyl macromonomer, and at the same time an alkenyl group and a macromonomer polymer molecular chain are introduced to obtain a hydrophobic macromonomer. Finally, acrylamide, methacryloyloxyethyl trimethyl ammonium chloride, 2-acrylamido-2-methylpropanesulfonic acid, the temperature-resistant monomer, and the hydrophobic macromonomer are used as polymerization monomers for polymerization to form a polymer, and then diluted to form a copolymer solution. Then, the copolymer solution, a crosslinking agent, and a heat stabilizer are mixed evenly to obtain a temperature-resistant and salt-resistant high-efficiency gel; in this preparation method, methacryloyloxyethyl trimethyl ammonium chloride is used to provide cations, and 2-acrylamido-2-methylpropanesulfonic acid is used to provide anions, which can bind to both positively charged and negatively charged substances at the same time, enhance the adsorption of the gel on the rock surface, improve the oil displacement efficiency, and form an electric double layer structure, enhancing the electrostatic repulsion between the gel molecular chains and the interaction between the gel and water molecules, forming a stable hydration layer, thereby improving the salt resistance performance. By using the temperature-resistant monomer to provide a large number of naphthalene rings, the high-temperature stability of the gel can be improved, and the provided long carbon chains will entangle with each other to form a complex network structure, increasing the viscosity of the gel. By using the hydrophobic macromonomer to provide a large number of C-F bonds, the high-temperature stability of the gel is further improved, and the gel can have stronger hydrophobic association, and the provided macromonomer polymer molecular chain makes the formed network structure further entangled and complex, and uses a large number of functional groups on it to interact with surrounding molecules through hydrogen bonds and electrostatic interactions, thereby increasing the intermolecular binding force, making the molecules in the gel bind more closely together, hindering the flow of molecules, and further improving the viscosity of the gel; this preparation method integrates a variety of monomers with excellent temperature-resistant and salt-resistant properties through copolymerization technology, enabling the gel to withstand high temperatures without degradation or performance decline, and also showing excellent stability in a high-salinity environment, not losing the oil displacement effect due to the presence of salt, ensuring the activity and stability of the gel in high-temperature and high-salt content oil reservoir environments, significantly enhancing its oil displacement efficiency in crude oil exploitation, and thus greatly improving the crude oil exploitation efficiency and recovery rate. Detailed implementation mode

[0030] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0031] Example 1:

[0032] The preparation method of a temperature-resistant and salt-resistant high-efficiency gel in this example includes the following steps:

[0033] Step 1: Add 10 mmol of methacrylic acid and 20 mL of dichloromethane into a three-necked flask equipped with a stirrer, a thermometer, and a constant-pressure dropping funnel. Stir and react for 20 min at a temperature of 0 °C and a stirring rate of 300 r / min. Then, while stirring, gradually add dropwise a dichlorosulfoxide solution formed by dissolving 15 mL of thionyl dichloride in dichloromethane according to 10 mmol:15 mL, control the dropping rate at 1 drop / s. After the dropping is completed, continue to stir and react for 20 min. Then, continue to stir and react for 8 h under the condition of heating to 35 °C. After the reaction is completed, cool the reaction product to room temperature, and then remove the solvent by rotary evaporation to obtain Intermediate 1;

[0034] Step 2: Add 10 mmol of 1-naphthylamine and 40 mL of anhydrous ether into a three-necked flask equipped with a stirrer, a thermometer, a gas guide tube, and a constant-pressure dropping funnel. Introduce nitrogen for protection. Stir and react for 20 min at a temperature of 25 °C and a stirring rate of 300 r / min. Then, while stirring, gradually add dropwise 10 mmol of 1-bromohexadecane under the condition of heating to 80 °C, control the dropping rate at 1 drop / s. After the dropping is completed, continue to stir and react for 8 h. After the reaction is completed, cool the reaction product to room temperature, then add it to a sodium hydroxide solution with a mass fraction of 8%. Then, perform vacuum filtration, rotate and evaporate the filtrate to remove the solvent, and then recrystallize with dichloromethane to obtain Intermediate 2;

[0035] Step 3: Add 10 mmol of Intermediate 2 and 20 mL of dichloromethane into a three-necked flask equipped with a stirrer, a thermometer, and a constant-pressure dropping funnel. Stir and react for 20 min under the conditions of a temperature of -5°C and a stirring rate of 300 r / min. Then, while stirring, gradually add dropwise 20 mL of an Intermediate 1 solution formed by dissolving 11 mmol of Intermediate 1 in dichloromethane. Control the dropping rate at 1 drop / s. After the addition is complete, continue to stir and react for 20 min. Then, raise the temperature to 25°C and continue to stir and react for 6 h. After the reaction is completed, wash the reaction product successively with saturated sodium carbonate solution and distilled water twice, then dry it with anhydrous magnesium sulfate, then perform vacuum filtration, and rotary evaporate the filtrate to remove the solvent to obtain a temperature-resistant monomer;

[0036] Step 4: Add 11 mmol of isophorone diisocyanate, 0.04 g of dibutyltin dilaurate, and 50 mL of anhydrous acetone into a three-necked flask equipped with a stirrer, a thermometer, and a constant-pressure dropping funnel. Stir and react for 20 min under the conditions of a temperature of 25°C and a stirring rate of 300 r / min. Then, while stirring, gradually add dropwise 10 mmol of dodecafluoroheptanol. Control the dropping rate at 1 drop / s. After the addition is complete, raise the temperature to 80°C and continue to stir and react for 2 h. After the reaction is completed, cool the reaction product to room temperature, then add it to petroleum ether, then perform vacuum filtration, and place the filter cake in a vacuum drying oven and dry it at a temperature of 55°C for 2 h to obtain Intermediate 3;

[0037] Step 5: Add 10 mmol of Intermediate 3 and 70 mL of anhydrous acetone into a three-necked flask equipped with a stirrer and a thermometer. Stir and react for 20 min under the conditions of a temperature of 25°C and a stirring rate of 300 r / min. Then, add 11 mmol of APEG-2400 and raise the temperature to 40°C and continue to stir and react for 7 h. After the reaction is completed, cool the reaction product to room temperature, then add it to petroleum ether, then perform vacuum filtration, and place the filter cake in a vacuum drying oven and dry it at a temperature of 40°C for 2 h to obtain a hydrophobic macromonomer;

[0038] Step 6: Add 20 g of acrylamide, 1 g of methacryloyloxyethyl trimethyl ammonium chloride, 1 g of 2-acrylamido-2-methylpropanesulfonic acid, 0.05 g of temperature-resistant monomer, 0.1 g of hydrophobic macromonomer, 0.05 g of sodium dodecyl sulfate, and 60 g of deionized water into a three-necked flask equipped with a stirrer, a thermometer, and a gas pipe. Introduce nitrogen for protection. Stir and react for 20 min at a temperature of 25 °C and a stirring rate of 300 r / min. Then adjust the pH to 7 with a 10% sodium hydroxide solution by mass. After that, add 0.002 g of potassium persulfate and continue to stir and react at 35 °C for 8 h. After the reaction is completed, cool the reaction product to room temperature, and then add distilled water to adjust the copolymer concentration to 0.1 g / L to obtain a copolymer solution;

[0039] Step 7: Add 1000 mL of the copolymer solution, 0.01 g of glyoxal, and 0.005 g of sodium sulfite into a three-necked flask equipped with a stirrer, a thermometer, and a gas pipe. Introduce nitrogen for protection. Stir and react for 2 h at a temperature of 25 °C and a stirring rate of 300 r / min to obtain a temperature-resistant and salt-resistant high-efficiency gel.

[0040] Example 2:

[0041] This example is a preparation method of a temperature-resistant and salt-resistant high-efficiency gel, including the following steps:

[0042] Step 1: Add 10 mmol of methacrylic acid and 22 mL of dichloromethane into a three-necked flask equipped with a stirrer, a thermometer, and a constant-pressure dropping funnel. Stir and react for 25 min at a temperature of 5 °C and a stirring rate of 350 r / min. Then, while stirring, gradually dropwise add a dichlorosulfoxide solution formed by dissolving 11 mmol of dichlorosulfoxide in 15 mL of dichloromethane, control the dropping rate at 1 drop / s. After the dropping is completed, continue to stir and react for 25 min. Then continue to stir and react for 9 h at 38 °C. After the reaction is completed, cool the reaction product to room temperature, and then rotate the evaporator to remove the solvent to obtain Intermediate 1;

[0043] Step 2: Add 10 mmol of 1-naphthylamine and 45 mL of anhydrous ether into a three-necked flask equipped with a stirrer, a thermometer, a gas pipe, and a constant-pressure dropping funnel. Introduce nitrogen for protection. Stir and react for 25 min at a temperature of 28 °C and a stirring rate of 350 r / min. Then, while stirring, gradually dropwise add 10 mmol of 1-bromohexadecane at 82 °C, control the dropping rate at 1 drop / s. After the dropping is completed, continue to stir and react for 9 h. After the reaction is completed, cool the reaction product to room temperature, then add it to a 9% sodium hydroxide solution by mass, and then perform vacuum filtration. Rotate the evaporator to remove the solvent from the filtrate, and then recrystallize with dichloromethane to obtain Intermediate 2;

[0044] Step 3: Add 10 mmol of intermediate 2 and 22 mL of dichloromethane into a three-necked flask equipped with a stirrer, a thermometer, and a constant-pressure dropping funnel. Stir and react for 25 min at a temperature of -3°C and a stirring rate of 350 r / min. Then, while stirring, gradually add dropwise 22 mL of a solution of intermediate 1 formed by dissolving 12 mmol of intermediate 1 in 20 mL of dichloromethane, controlling the dropping rate at 1 drop / s. After the addition is complete, continue to stir and react for 25 min. Then, raise the temperature to 28°C and continue to stir and react for 6.5 h. After the reaction is completed, wash the reaction product successively with saturated sodium carbonate solution and distilled water twice, then dry it with anhydrous magnesium sulfate, then perform vacuum filtration, and rotary evaporate the filtrate to remove the solvent to obtain a temperature-resistant monomer;

[0045] Step 4: Add 11.5 mmol of isophorone diisocyanate, 0.05 g of dibutyltin dilaurate, and 52 mL of anhydrous acetone into a three-necked flask equipped with a stirrer, a thermometer, and a constant-pressure dropping funnel. Stir and react for 25 min at a temperature of 28°C and a stirring rate of 350 r / min. Then, while stirring, gradually add dropwise 10 mmol of dodecafluoroheptanol, controlling the dropping rate at 1 drop / s. After the addition is complete, raise the temperature to 82°C and continue to stir and react for 2.5 h. After the reaction is completed, cool the reaction product to room temperature, then add it to petroleum ether, then perform vacuum filtration, and place the filter cake in a vacuum drying oven and dry it at a temperature of 58°C for 2.5 h to obtain intermediate 3;

[0046] Step 5: Add 10 mmol of intermediate 3 and 75 mL of anhydrous acetone into a three-necked flask equipped with a stirrer and a thermometer. Stir and react for 25 min at a temperature of 28°C and a stirring rate of 350 r / min. Then, add 12 mmol of HPEG-2400 and raise the temperature to 42°C and continue to stir and react for 7.5 h. After the reaction is completed, cool the reaction product to room temperature, then add it to petroleum ether, then perform vacuum filtration, and place the filter cake in a vacuum drying oven and dry it at a temperature of 42°C for 2.5 h to obtain a hydrophobic macromonomer;

[0047] Step 6: Add 20 g of acrylamide, 10.5 g of methacryloyloxyethyltrimethylammonium chloride, 10.5 g of 2-acrylamido-2-methylpropanesulfonic acid, 5 g of temperature-resistant monomer, 7.5 g of hydrophobic macromonomer, 2.5 g of sodium dodecyl sulfate, and 80 g of deionized water into a three-necked flask equipped with a stirrer, a thermometer, and a gas pipe. Introduce nitrogen for protection. Stir and react for 25 min under the conditions of a temperature of 28 °C and a stirring rate of 350 r / min. Then adjust the pH to 8 with a 12% sodium hydroxide solution by mass. After that, add 0.5 g of potassium persulfate and continue to stir and react for 22 h under the condition of heating to 55 °C. After the reaction is completed, cool the reaction product to room temperature. Then add distilled water to adjust the copolymer concentration to 2 g / L to obtain a copolymer solution;

[0048] Step 7: Add 1000 mL of the copolymer solution, 0.5 g of glyoxal, and 0.5 g of sodium sulfite into a three-necked flask equipped with a stirrer, a thermometer, and a gas pipe. Introduce nitrogen for protection. Stir and react for 2.5 h under the conditions of a temperature of 28 °C and a stirring rate of 350 r / min to obtain a temperature-resistant and salt-resistant high-efficiency gel.

[0049] Example 3:

[0050] This example is a preparation method of a temperature-resistant and salt-resistant high-efficiency gel, including the following steps:

[0051] Step 1: Add 10 mmol of methacrylic acid and 25 mL of dichloromethane into a three-necked flask equipped with a stirrer, a thermometer, and a constant-pressure dropping funnel. Stir and react for 30 min under the conditions of a temperature of 10 °C and a stirring rate of 400 r / min. Then, while stirring, gradually add dropwise a dichlorosulfoxide solution formed by dissolving 18 mL of thionyl chloride in dichloromethane according to 12 mmol:15 mL, control the dropping rate at 2 drops / s. After the dropping is completed, continue to stir and react for 30 min. Then continue to stir and react for 10 h under the condition of heating to 40 °C. After the reaction is completed, cool the reaction product to room temperature. Then rotate and evaporate to remove the solvent to obtain Intermediate 1;

[0052] Step 2: Add 10 mmol of 1-naphthylamine and 50 mL of anhydrous ether into a three-necked flask equipped with a stirrer, a thermometer, a gas pipe, and a constant-pressure dropping funnel. Introduce nitrogen for protection. Stir and react for 30 min under the conditions of a temperature of 30 °C and a stirring rate of 400 r / min. Then, while stirring, gradually add dropwise 10 mmol of 1-bromohexadecane at 85 °C, control the dropping rate at 2 drops / s. After the dropping is completed, continue to stir and react for 10 h. After the reaction is completed, cool the reaction product to room temperature. Then add it to a 10% sodium hydroxide solution by mass. Then perform vacuum filtration. Rotate and evaporate the filtrate to remove the solvent. Then recrystallize with dichloromethane to obtain Intermediate 2;

[0053] Step 3: Add 10 mmol of intermediate 2 and 25 mL of dichloromethane into a three-necked flask equipped with a stirrer, a thermometer and a constant-pressure dropping funnel. Stir and react for 30 min at a temperature of 0 °C and a stirring rate of 400 r / min. Then, while stirring, gradually add dropwise 25 mL of a solution of intermediate 1 formed by dissolving 13 mmol of intermediate 1 in 20 mL of dichloromethane, controlling the dropping rate at 2 drops / s. After the addition is complete, continue to stir and react for 30 min. Then, raise the temperature to 30 °C and continue to stir and react for 7 h. After the reaction is completed, wash the reaction product successively with saturated sodium carbonate solution and distilled water three times, then dry it with anhydrous magnesium sulfate, then perform vacuum filtration, and rotary evaporate the filtrate to remove the solvent to obtain a temperature-resistant monomer;

[0054] Step 4: Add 12 mmol of isophorone diisocyanate, 0.06 g of dibutyltin dilaurate and 55 mL of anhydrous acetone into a three-necked flask equipped with a stirrer, a thermometer and a constant-pressure dropping funnel. Stir and react for 30 min at a temperature of 30 °C and a stirring rate of 400 r / min. Then, while stirring, gradually add dropwise 10 mmol of dodecafluoroheptanol, controlling the dropping rate at 2 drops / s. After the addition is complete, raise the temperature to 85 °C and continue to stir and react for 3 h. After the reaction is completed, cool the reaction product to room temperature, then add it to petroleum ether, then perform vacuum filtration, and place the filter cake in a vacuum drying oven and dry it at a temperature of 60 °C for 3 h to obtain intermediate 3;

[0055] Step 5: Add 10 mmol of intermediate 3 and 80 mL of anhydrous acetone into a three-necked flask equipped with a stirrer and a thermometer. Stir and react for 30 min at a temperature of 30 °C and a stirring rate of 400 r / min. Then, add 13 mmol of EPEG-3000 and raise the temperature to 45 °C and continue to stir and react for 8 h. After the reaction is completed, cool the reaction product to room temperature, then add it to petroleum ether, then perform vacuum filtration, and place the filter cake in a vacuum drying oven and dry it at a temperature of 45 °C for 3 h to obtain a hydrophobic macromonomer;

[0056] Step 6: Add 20 g of acrylamide, 20 g of methacryloyloxyethyltrimethylammonium chloride, 20 g of 2-acrylamido-2-methylpropanesulfonic acid, 10 g of temperature-resistant monomer, 15 g of hydrophobic macromonomer, 5 g of sodium dodecylbenzenesulfonate, and 100 g of deionized water into a three-necked flask equipped with a stirrer, a thermometer, and a gas inlet tube. Introduce nitrogen for protection and stir the reaction at 30 °C and a stirring rate of 400 r / min for 30 min. Then adjust the pH to 9 with a 15% sodium hydroxide solution, add 1 g of ammonium persulfate, and continue stirring the reaction at 75 °C for 36 h. After the reaction is completed, cool the reaction product to room temperature, and then add distilled water to adjust the copolymer concentration to 4 g / L to obtain a copolymer solution;

[0057] Step 7: Add 1000 mL of the copolymer solution, 1 g of glutaraldehyde, and 1 g of sodium sulfite into a three-necked flask equipped with a stirrer, a thermometer, and a gas inlet tube. Introduce nitrogen for protection and stir the reaction at 30 °C and a stirring rate of 400 r / min for 3 h to obtain a temperature-resistant and salt-resistant high-efficiency gel.

[0058] Comparative Example 1:

[0059] This comparative example is a preparation method of a temperature-resistant and salt-resistant high-efficiency gel, including the following steps:

[0060] Step 1: Add 20 g of acrylamide, 5 g of sodium dodecylbenzenesulfonate, and 100 g of deionized water into a three-necked flask equipped with a stirrer, a thermometer, and a gas inlet tube. Introduce nitrogen for protection and stir the reaction at 30 °C and a stirring rate of 400 r / min for 30 min. Then adjust the pH to 9 with a 15% sodium hydroxide solution, add 1 g of ammonium persulfate, and continue stirring the reaction at 75 °C for 36 h. After the reaction is completed, cool the reaction product to room temperature, and then add distilled water to adjust the copolymer concentration to 4 g / L to obtain a copolymer solution;

[0061] Step 2: Add 1000 mL of the copolymer solution, 1 g of glutaraldehyde, and 1 g of sodium sulfite into a three-necked flask equipped with a stirrer, a thermometer, and a gas inlet tube. Introduce nitrogen for protection and stir the reaction at 30 °C and a stirring rate of 400 r / min for 3 h to obtain a temperature-resistant and salt-resistant high-efficiency gel.

[0062] Comparative Example 2:

[0063] This comparative example is a preparation method of a temperature-resistant and salt-resistant high-efficiency gel, including the following steps:

[0064] Step 1: Add 20 g of acrylamide, 20 g of methacryloyloxyethyl trimethyl ammonium chloride, 20 g of 2-acrylamido-2-methylpropane sulfonic acid, 5 g of sodium dodecyl benzene sulfonate, and 100 g of deionized water into a three-necked flask equipped with a stirrer, a thermometer, and a gas pipe. Introduce nitrogen for protection. Stir and react for 30 min at a temperature of 30°C and a stirring rate of 400 r / min. Then adjust the pH to 9 with a 15% sodium hydroxide solution by mass. After that, add 1 g of ammonium persulfate and continue to stir and react at 75°C for 36 h. After the reaction is completed, cool the reaction product to room temperature, and then add distilled water to adjust the copolymer concentration to 4 g / L to obtain a copolymer solution;

[0065] Step 2: Add 1000 mL of the copolymer solution, 1 g of glutaraldehyde, and 1 g of sodium sulfite into a three-necked flask equipped with a stirrer, a thermometer, and a gas pipe. Introduce nitrogen for protection. Stir and react for 3 h at a temperature of 30°C and a stirring rate of 400 r / min to obtain a temperature-resistant and salt-resistant high-efficiency gel.

[0066] Comparative Example 3:

[0067] This comparative example is a preparation method of a temperature-resistant and salt-resistant high-efficiency gel, including the following steps:

[0068] Step 1: Add 10 mmol of methacrylic acid and 25 mL of dichloromethane into a three-necked flask equipped with a stirrer, a thermometer, and a constant-pressure dropping funnel. Stir and react for 30 min at a temperature of 10°C and a stirring rate of 400 r / min. Then, while stirring, gradually add dropwise a dichlorosulfoxide solution formed by dissolving 18 mL of thionyl dichloride in dichloromethane according to 12 mmol:15 mL, control the dropping rate at 2 drops / s. After the dropping is completed, continue to stir and react for 30 min. Then continue to stir and react at 40°C for 10 h. After the reaction is completed, cool the reaction product to room temperature, and then rotate and evaporate to remove the solvent to obtain Intermediate 1;

[0069] Step 2: Add 10 mmol of 1-naphthylamine and 50 mL of anhydrous ether into a three-necked flask equipped with a stirrer, a thermometer, a gas pipe, and a constant-pressure dropping funnel. Introduce nitrogen for protection. Stir and react for 30 min at a temperature of 30°C and a stirring rate of 400 r / min. Then, while stirring, gradually add dropwise 10 mmol of 1-bromohexadecane at 85°C, control the dropping rate at 2 drops / s. After the dropping is completed, continue to stir and react for 10 h. After the reaction is completed, cool the reaction product to room temperature, then add it to a 10% sodium hydroxide solution by mass, then perform vacuum filtration, rotate and evaporate the filtrate to remove the solvent, and then recrystallize with dichloromethane to obtain Intermediate 2;

[0070] Step 3: Add 10 mmol of intermediate 2 and 25 mL of dichloromethane into a three-necked flask equipped with a stirrer, a thermometer and a constant-pressure dropping funnel. Stir and react for 30 min at a temperature of 0 °C and a stirring rate of 400 r / min. Then, while stirring, gradually add dropwise 25 mL of a solution of intermediate 1 formed by dissolving 13 mmol of intermediate 1 in 20 mL of dichloromethane. Control the dropping rate at 2 drops / s. After the dropping is completed, continue to stir and react for 30 min. Then, raise the temperature to 30 °C and continue to stir and react for 7 h. After the reaction is completed, wash the reaction product successively with saturated sodium carbonate solution and distilled water three times, then dry it with anhydrous magnesium sulfate, then perform vacuum filtration, and rotary evaporate the filtrate to remove the solvent to obtain a temperature-resistant monomer;

[0071] Step 4: Add 20 g of acrylamide, 20 g of methacryloyloxyethyltrimethylammonium chloride, 20 g of 2-acrylamido-2-methylpropanesulfonic acid, 10 g of the temperature-resistant monomer, 5 g of sodium dodecylbenzenesulfonate and 100 g of deionized water into a three-necked flask equipped with a stirrer, a thermometer and a gas pipe. Introduce nitrogen for protection. Stir and react for 30 min at a temperature of 30 °C and a stirring rate of 400 r / min. Then, adjust the pH to 9 with a 15% sodium hydroxide solution by mass fraction. Then, add 1 g of ammonium persulfate and raise the temperature to 75 °C and continue to stir and react for 36 h. After the reaction is completed, cool the reaction product to room temperature, and then add distilled water to adjust the copolymer concentration to 4 g / L to obtain a copolymer solution;

[0072] Step 5: Add 1000 mL of the copolymer solution, 1 g of glutaraldehyde and 1 g of sodium sulfite into a three-necked flask equipped with a stirrer, a thermometer and a gas pipe. Introduce nitrogen for protection. Stir and react for 3 h at a temperature of 30 °C and a stirring rate of 400 r / min to obtain a temperature-resistant and salt-resistant high-efficiency gel.

[0073] Comparative Example 4:

[0074] This comparative example is a preparation method of a temperature-resistant and salt-resistant high-efficiency gel, including the following steps:

[0075] Step 1: Add 12 mmol of isophorone diisocyanate, 0.06 g of dibutyltin dilaurate and 55 mL of anhydrous acetone into a three-necked flask equipped with a stirrer, a thermometer and a constant-pressure dropping funnel. Stir and react for 30 min at a temperature of 30 °C and a stirring rate of 400 r / min. Then, while stirring, gradually add dropwise 10 mmol of dodecafluoroheptanol. Control the dropping rate at 2 drops / s. After the dropping is completed, raise the temperature to 85 °C and continue to stir and react for 3 h. After the reaction is completed, cool the reaction product to room temperature, then add it to petroleum ether, then perform vacuum filtration, and place the filter cake in a vacuum drying oven and dry it at a temperature of 60 °C for 3 h to obtain intermediate 3;

[0076] Step 2: Add 10 mmol of intermediate 3 and 80 mL of anhydrous acetone into a three-necked flask equipped with a stirrer and a thermometer. Stir and react for 30 min at a temperature of 30 °C and a stirring rate of 400 r / min. Then add 13 mmol of EPEG-3000 and continue to stir and react for 8 h under the condition of heating to 45 °C. After the reaction is completed, cool the reaction product to room temperature, then add it into petroleum ether, and then carry out vacuum filtration. Place the filter cake in a vacuum drying oven and dry it for 3 h at a temperature of 45 °C to obtain a hydrophobic macromonomer;

[0077] Step 3: Add 20 g of acrylamide, 20 g of methacryloyloxyethyltrimethylammonium chloride, 20 g of 2-acrylamido-2-methylpropanesulfonic acid, 15 g of hydrophobic macromonomer, 5 g of sodium dodecylbenzenesulfonate, and 100 g of deionized water into a three-necked flask equipped with a stirrer, a thermometer, and a gas guide tube. Pass in nitrogen for protection. Stir and react for 30 min at a temperature of 30 °C and a stirring rate of 400 r / min. Then adjust the pH to 9 with a 15% sodium hydroxide solution, then add 1 g of ammonium persulfate and continue to stir and react for 36 h under the condition of heating to 75 °C. After the reaction is completed, cool the reaction product to room temperature, and then add distilled water to adjust the copolymer concentration to 4 g / L to obtain a copolymer solution;

[0078] Step 4: Add 1000 mL of copolymer solution, 1 g of glutaraldehyde, and 1 g of sodium sulfite into a three-necked flask equipped with a stirrer, a thermometer, and a gas guide tube. Pass in nitrogen for protection. Stir and react for 3 h at a temperature of 30 °C and a stirring rate of 400 r / min to obtain a high-temperature and salt-resistant efficient gel.

[0079] The apparent viscosities η1 of the high-temperature and salt-resistant efficient gels of Examples 1-3 and Comparative Examples 1-4 were sheared at a shear rate of 170 s -1 at 25 °C for 120 min;

[0080] The apparent viscosities η2 of the high-temperature and salt-resistant efficient gels of Examples 1-3 and Comparative Examples 1-4 were sheared at a shear rate of 170 s -1 at 160 °C for 120 min;

[0081] Add sodium chloride to the high-temperature and salt-resistant efficient gels of Examples 1-3 and Comparative Examples 1-4, control the concentration of sodium chloride to be 100 g / L, and then the apparent viscosity η3 was sheared at a shear rate of 170 s -1 at 25 °C for 120 min;

[0082] Sodium chloride was added to the high-temperature and salt-resistant high-efficiency gels of Examples 1-3 and Comparative Examples 1-4, and the concentration of sodium chloride was controlled to be 100 g / L. Then, the apparent viscosity η4 was measured after shearing at a shear rate of 160 °C for 170 s for 120 min. -1 The apparent viscosity η4 was measured after shearing at a shear rate of 160 °C for 170 s for 120 min.

[0083] The test results are shown in the following table:

[0084] Sample η1, mPa·s η2, mPa·s η3, mPa·s η4, mPa·s Example 1 205 182 193 170 Example 2 211 187 199 176 Example 3 218 194 205 184 Comparative Example 1 132 91 123 76 Comparative Example 2 155 114 123 102 Comparative Example 3 163 135 132 118 Comparative Example 4 161 133 146 123

[0085] Referring to the data in the above table and based on the comparison between Examples 1-3 and Comparative Examples 1-4, it can be seen that the high-temperature and salt-resistant high-efficiency gels in this application have excellent high-temperature and salt-resistant properties.

[0086] In the description of this specification, the description referring to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0087] The above content is only an example and explanation of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined by the claims of the present invention, they should fall within the protection scope of the present invention.

Claims

1. A preparation method of a temperature-resistant and salt-resistant high-efficiency gel, characterized in that, It includes the following steps: Step 1: Stir and react methacrylic acid and dichloromethane, then dropwise add thionyl chloride solution drop by drop while stirring. After the addition is complete, continue stirring and reacting. After the reaction is completed, cool the reaction product, and then perform rotary evaporation to obtain Intermediate 1; Step 2: Stir and react 1-naphthylamine and anhydrous ether, then dropwise add 1-bromohexadecane drop by drop while stirring. After the addition is complete, continue stirring and reacting. After the reaction is completed, cool the reaction product, then add it to sodium hydroxide solution, then perform vacuum filtration. Rotate and evaporate the filtrate, and then recrystallize with dichloromethane to obtain Intermediate 2; Step 3: Stir and react Intermediate 2 and dichloromethane, then dropwise add Intermediate 1 solution drop by drop while stirring. After the addition is complete, continue stirring and reacting. After the reaction is completed, wash the reaction product successively with saturated sodium carbonate solution and distilled water, then dry it, then perform vacuum filtration. Rotate and evaporate the filtrate to obtain a temperature-resistant monomer; Step 4: Stir and react isophorone diisocyanate, dibutyltin dilaurate and anhydrous acetone, then dropwise add dodecafluoroheptanol drop by drop while stirring. After the addition is complete, continue stirring and reacting. After the reaction is completed, cool the reaction product, then add it to petroleum ether, then perform vacuum filtration. Dry the filter cake to obtain Intermediate 3; Step 5: Stir and react Intermediate 3 and anhydrous acetone, then add vinyl macromonomer and continue stirring and reacting. After the reaction is completed, cool the reaction product, then add it to petroleum ether, then perform vacuum filtration. Dry the filter cake to obtain a hydrophobic macromonomer; Step 6: Stir and react acrylamide, methacryloyloxyethyl trimethyl ammonium chloride, 2-acrylamido-2-methylpropanesulfonic acid, temperature-resistant monomer, hydrophobic macromonomer, surfactant and deionized water, then adjust the pH with sodium hydroxide solution, then add persulfate and continue stirring and reacting. After the reaction is completed, cool the reaction product, then add distilled water for dilution to obtain a copolymer solution; Step 7: Stir and react the copolymer solution, crosslinking agent and heat stabilizer to obtain a temperature-resistant and salt-resistant high-efficiency gel.

2. The preparation method of a temperature-resistant and salt-resistant high-efficiency gel according to claim 1, characterized in that, In Step 1, the dosage ratio of the methacrylic acid, dichloromethane and thionyl chloride solution is 10 mmol: 20 - 25 mL: 15 - 18 mL; the thionyl chloride solution is a solution formed by dissolving thionyl chloride according to 10 - 12 mmol: 15 mL in dichloromethane.

3. The preparation method of a temperature-resistant and salt-resistant high-efficiency gel according to claim 1, characterized in that, In Step 2, the dosage ratio of the 1-naphthylamine, anhydrous ether and 1-bromohexadecane is 10 mmol: 40 - 50 mL: 10 mmol; the mass fraction of the sodium hydroxide solution is 8 - 10%.

4. The preparation method of a temperature-resistant and salt-resistant high-efficiency gel according to claim 1, characterized in that, In Step 3, the dosage ratio of the Intermediate 2, dichloromethane and Intermediate 1 solution is 10 mmol: 20 - 25 mL: 20 - 25 mL; the Intermediate 1 solution is a solution formed by dissolving Intermediate 1 according to 11 - 13 mmol: 20 mL in dichloromethane.

5. The preparation method of a temperature-resistant and salt-resistant high-efficiency gel according to claim 1, characterized in that, In Step 4, the dosage ratio of the isophorone diisocyanate, dibutyltin dilaurate, anhydrous acetone and dodecafluoroheptanol is 11 - 12 mmol: 0.04 - 0.06 g: 50 - 55 mL: 10 mmol.

6. The preparation method of a temperature-resistant and salt-resistant high-efficiency gel according to claim 1, wherein The dosage ratio of the intermediate 3, anhydrous acetone and vinyl macromonomer in Step 5 is 10 mmol: 70 - 80 mL: 11 - 13 mmol; the vinyl macromonomer is one of APEG-2400, HPEG-2400 and EPEG-3000.

7. The preparation method of a temperature-resistant and salt-resistant high-efficiency gel according to claim 1, characterized in that, The dosage ratio of acrylamide, methylacryloyloxyethyl trimethyl ammonium chloride, 2-acrylamido-2-methylpropanesulfonic acid, temperature-resistant monomer, hydrophobic macromonomer, surfactant, deionized water and persulfate in Step 6 is 20 g: 1 - 20 g: 1 - 20 g: 0.05 - 10 g: 0.1 - 15 g: 0.05 - 5 g: 60 - 100 g: 0.002 - 1 g; the surfactant is one of sodium dodecyl sulfate and sodium dodecylbenzenesulfonate; the persulfate is one of potassium persulfate and ammonium persulfate; the mass fraction of the sodium hydroxide solution is 10 - 15%.

8. The preparation method of a temperature-resistant and salt-resistant high-efficiency gel according to claim 1, characterized in that, The dosage ratio of the copolymer solution, crosslinking agent and heat stabilizer in Step 7 is 1000 mL: 0.01 - 1 g: 0.005 - 1 g; the crosslinking agent is one of glyoxal and glutaraldehyde; the heat stabilizer is sodium sulfite.

9. A high-temperature and salt-resistant efficient gel, characterized in that, The temperature-resistant and salt-resistant high-efficiency gel is prepared according to the preparation method of the temperature-resistant and salt-resistant high-efficiency gel described in any one of claims 1 - 8.

10. Use of a temperature-resistant and salt-resistant high-efficiency gel prepared according to the preparation method of the temperature-resistant and salt-resistant high-efficiency gel described in any one of claims 1 - 8 in the field of oil exploitation.