Oil displacement agent for high-salinity, low-permeability oil reservoirs containing betaine-type surfactants and its preparation method

Abstract

The invention relates to the technical field of oilfield exploitation, and discloses a high-salinity low-permeability reservoir oil displacement agent containing a betaine-type surfactant and a preparation method thereof. The invention uses hexamethylene diisocyanate, perfluorononenyloxybenzenesulfonyl diethylenetriamine, and lysine-based betaine as polymerization monomers to react to obtain a polymer-type betaine-type surfactant. The surfactant contains a polar urea group, as well as a hydrophilic hydroxyl group and a betaine structure, so that the surfactant has good water solubility. It exhibits a high viscosity in water and highly mineralized mineralized water, has good salt resistance, and still maintains a high viscosity and viscosity retention rate after shearing, showing excellent anti-shear performance. The betaine-type surfactant contains a perfluoroalkyl group and a betaine structure, can form an ultra-low interfacial tension with crude oil, and is beneficial to improving oil displacement efficiency and recovery rate.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield exploitation, in particular to a high-salinity low-permeability oil reservoir oil displacement agent containing a betaine-type surfactant and a preparation method thereof. Background Art

[0002] In recent years, my country's demand for oil has increased year by year. As the production of medium and high permeability oil reservoirs has reached saturation, the production of low permeability oil reservoirs is imminent. Among them, chemical flooding is the most promising oil recovery method in tertiary oil recovery. The surfactant in the chemical flooding agent has a great influence on the oil recovery efficiency and recovery rate. Surfactant solution can form ultra-low interfacial tension with crude oil, so surfactant flooding is an effective method to improve the recovery rate of low permeability oil layers.

[0003] Betaine-type amphoteric surfactants have broad application prospects in the field of chemical oil displacement agents and oil production. Patent CN107916097B discloses a viscoelastic betaine surfactant composition for oil displacement obtained by compounding betaine surfactants and anionic surfactants, which has the advantage of good oil displacement effect in high-temperature medium and low permeability oil reservoirs. Fluorine-containing surfactants have high surface activity and excellent thermal and chemical stability, and can be used in harsh oil production environments. The present invention aims to prepare a high-salinity low-permeability oil reservoir oil displacement agent containing betaine-type surfactants with good shear resistance and high oil displacement efficiency. Summary of the invention

[0004] The technical problem solved by the present invention is to provide a high-salinity low-permeability reservoir oil displacement agent containing a betaine-type surfactant and a preparation method thereof, thereby solving the problems of poor salt resistance and shear resistance and low oil displacement efficiency of traditional oil displacement agents.

[0005] The technical solution provided by the present invention is:

[0006] A method for preparing a high-salinity low-permeability oil reservoir oil displacement agent containing a betaine-type surfactant:

[0007] S1. Add solvent, potassium carbonate, perfluorononenyloxybenzenesulfonyl chloride, and 1,7-bis-tert-butyloxycarbonyldiethylenetriamine to a reaction flask, reflux at 75-85° C. for 4-8 hours, cool, remove acetonitrile by rotary evaporation, wash with water, dissolve the product in dichloromethane, add trifluoroacetic acid, stir at room temperature for 2-4 hours, remove the solvent by rotary evaporation, wash with water, dissolve the product in dichloromethane, add water for extraction, collect the dichloromethane phase, and concentrate by rotary evaporation to obtain perfluorononenyloxybenzenesulfonyldiethylenetriamine;

[0008] S2. Add tetrahydrofuran, hexamethylene diisocyanate, perfluorononenyloxybenzenesulfonyl diethylenetriamine and lysine betaine into a reaction bottle, stir to react, remove tetrahydrofuran by rotary evaporation, wash with ethanol, and obtain a betaine-type surfactant.

[0009] Furthermore, the solvent in S1 includes dichloromethane, chloroform, acetonitrile or tetrahydrofuran.

[0010] Furthermore, the ratio of potassium carbonate, perfluorononenyloxybenzenesulfonyl chloride and 1,7-bis-tert-butyloxycarbonyldiethylenetriamine in S1 is (1.5-2.5) mol:1 mol:(1.1-1.4) mol.

[0011] Furthermore, the ratio of hexamethylene diisocyanate, perfluorononenyloxybenzenesulfonyl diethylenetriamine, and lysine betaine in S2 is 1 mol:(0.04-0.2) mol:(0.8-0.96) mol.

[0012] Further, the reaction in S2 is refluxed at 65-75° C. for 2-4 h.

[0013] Further, the preparation method of lysine betaine is:

[0014] S11. Add dichloromethane, 2,6-di-tert-butoxycarbonylaminocaproic acid, N,N-dimethylethylenediamine, N,N-dicyclohexylcarbodiimide (DCC), and 1-hydroxybenzotriazole (HOBt) to a reaction bottle, and stir the reaction at 25-40°C for 6-12 hours. Remove dichloromethane by rotary evaporation, wash with petroleum ether, dissolve the product in dichloromethane, add trifluoroacetic acid (TFA), stir at room temperature for 2-4 hours, remove the solvent by rotary evaporation, wash with petroleum ether, dissolve the product in dichloromethane, add water for extraction, collect the dichloromethane phase, and concentrate by rotary evaporation to obtain N,N-dimethylaminolysine.

[0015] S12. Add isopropanol, N,N-dimethylaminolysine and sodium 3-chloro-2-hydroxypropanesulfonate to a reaction flask. After the reaction, remove the isopropanol by rotary evaporation, wash with petroleum ether, and recrystallize the product with acetone to obtain lysine betaine.

[0016] Furthermore, in S11, the ratio of 2,6-di-tert-butoxycarbonylaminocaproic acid, N,N-dimethylethylenediamine, N,N-dicyclohexylcarbodiimide, and 1-hydroxybenzotriazole is 1 mol:(0.9-1.2) mol:(1-1.2) mol:(1-1.2) mol.

[0017] Furthermore, the ratio of N,N-dimethylaminolysine to sodium 3-chloro-2-hydroxypropanesulfonate in S12 is 1 mol:(1-1.4) mol.

[0018] Further, the reaction in S12 is refluxed at 80-90° C. for 5-10 h.

[0019] The technical effect of the present invention is as follows: the present invention uses hexamethylene diisocyanate, perfluorononenyloxybenzenesulfonyl diethylenetriamine and lysine betaine as polymerization monomers to react and obtain a polymer betaine type surfactant. The surfactant contains polar urea groups, as well as hydrophilic hydroxyl groups and betaine structures, so that the surfactant has good water solubility.

[0020] The betaine-type surfactant prepared by the present invention exhibits high viscosity in water and mineralized water with high mineralization, has good salt resistance, and still maintains high viscosity and viscosity retention rate after shearing, showing excellent anti-shear performance.

[0021] The betaine-type surfactant prepared by the present invention contains a perfluoroalkyl group and a betaine structure, can form an ultra-low interfacial tension with crude oil, is beneficial to improving oil displacement efficiency and recovery rate, and can be used as an oil displacement agent and is suitable for exploitation of high-salinity and low-permeability oil reservoirs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the reaction route for preparing lysine betaine.

[0023] Figure 2 This is a reaction route for preparing perfluorononenyloxybenzenesulfonyldiethylenetriamine.

[0024] Figure 3 This is the reaction route for preparing betaine-type surfactants. DETAILED DESCRIPTION

[0025] The following is a clear and complete description of the embodiments of the invention provided in this specification. Based on these descriptions, a person of ordinary skill in the art will be able to implement the embodiments of the invention provided in this specification.

[0026] Example 1

[0027] Add 70 mL of dichloromethane, 6 mmol of 2,6-di-tert-butyloxycarbonylaminocaproic acid, 6 mmol of N,N-dimethylethylenediamine, 6.5 mmol of N,N-dicyclohexylcarbodiimide, and 6.5 mmol of 1-hydroxybenzotriazole to the reaction bottle, stir and react at 40°C for 6 h, remove dichloromethane by rotary evaporation, wash with petroleum ether, dissolve the product in 50 mL of dichloromethane, add 7 mL of trifluoroacetic acid, stir at room temperature for 4 h, remove the solvent by rotary evaporation, wash with petroleum ether, dissolve the product in dichloromethane, add water for extraction, collect the dichloromethane phase, and concentrate by rotary evaporation to obtain N,N-dimethylaminolysine.

[0028] Add 50 mL of isopropanol, 6 mmol of N,N-dimethylaminolysine, and 6 mmol of sodium 3-chloro-2-hydroxypropanesulfonate to the reaction bottle, stir and reflux at 80°C for 10 h, remove isopropanol by rotary evaporation, wash with petroleum ether, and recrystallize the product with acetone to obtain lysine betaine.

[0029] Add 50 mL of dichloromethane, 20 mmol of potassium carbonate, 8 mmol of perfluorononenyloxybenzenesulfonyl chloride, and 11.2 mmol of 1,7-bis-tert-butyloxycarbonyldiethylenetriamine to the reaction bottle, reflux at 80°C for 6 h, cool, remove acetonitrile by rotary evaporation, wash with water, dissolve the product in 50 mL of dichloromethane, add 10 mL of trifluoroacetic acid, stir at room temperature for 2 h, remove the solvent by rotary evaporation, wash with water, dissolve the product in dichloromethane, add water for extraction, collect the dichloromethane phase, and concentrate by rotary evaporation to obtain perfluorononenyloxybenzenesulfonyldiethylenetriamine;

[0030] Add 80 mL of tetrahydrofuran, 10 mmol of hexamethylene diisocyanate, 0.4 mmol of perfluorononenyloxybenzenesulfonyl diethylenetriamine, and 9.6 mmol of lysine betaine into a reaction bottle, stir and reflux at 65°C for 3 h, remove tetrahydrofuran by rotary evaporation, wash with ethanol, and obtain a betaine-type surfactant.

[0031] Example 2

[0032] Add 80 mL of dichloromethane, 6 mmol of 2,6-di-tert-butyloxycarbonylaminocaproic acid, 7.2 mmol of N,N-dimethylethylenediamine, 7.2 mmol of N,N-dicyclohexylcarbodiimide, and 7.2 mmol of 1-hydroxybenzotriazole to the reaction bottle, stir and react at 30°C for 6 h, remove dichloromethane by rotary evaporation, wash with petroleum ether, dissolve the product in 50 mL of dichloromethane, add 6 mL of trifluoroacetic acid, stir at room temperature for 3 h, remove the solvent by rotary evaporation, wash with petroleum ether, dissolve the product in dichloromethane, add water for extraction, collect the dichloromethane phase, and concentrate by rotary evaporation to obtain N,N-dimethylaminolysine.

[0033] Add 50 mL of isopropanol, 6 mmol of N,N-dimethylaminolysine, and 6.5 mmol of sodium 3-chloro-2-hydroxypropanesulfonate to the reaction bottle, stir and reflux at 85°C for 8 h, remove isopropanol by rotary evaporation, wash with petroleum ether, and recrystallize the product with acetone to obtain lysine betaine.

[0034] Add 50 mL of tetrahydrofuran, 12 mmol of potassium carbonate, 8 mmol of perfluorononenyloxybenzenesulfonyl chloride, and 8.8 mmol of 1,7-bis-tert-butyloxycarbonyldiethylenetriamine to a reaction bottle, reflux at 85°C for 4 h, cool, remove acetonitrile by rotary evaporation, wash with water, dissolve the product in 50 mL of dichloromethane, add 8 mL of trifluoroacetic acid, stir at room temperature for 3 h, remove the solvent by rotary evaporation, wash with water, dissolve the product in dichloromethane, add water for extraction, collect the dichloromethane phase, and concentrate by rotary evaporation to obtain perfluorononenyloxybenzenesulfonyldiethylenetriamine;

[0035] Add 100 mL of tetrahydrofuran, 10 mmol of hexamethylene diisocyanate, 1 mmol of perfluorononenyloxybenzenesulfonyl diethylenetriamine, and 9 mmol of lysine betaine into a reaction bottle, stir and reflux at 65°C for 3 h, remove tetrahydrofuran by rotary evaporation, wash with ethanol, and obtain a betaine-type surfactant.

[0036] Example 3

[0037] Add 60 mL of dichloromethane, 6 mmol of 2,6-di-tert-butyloxycarbonylaminocaproic acid, 5.4 mmol of N,N-dimethylethylenediamine, 6 mmol of N,N-dicyclohexylcarbodiimide, and 6 mmol of 1-hydroxybenzotriazole to the reaction bottle, stir and react at 25°C for 12 hours, remove dichloromethane by rotary evaporation, wash with petroleum ether, dissolve the product in 50 mL of dichloromethane, add 7 mL of trifluoroacetic acid, stir at room temperature for 3 hours, remove the solvent by rotary evaporation, wash with petroleum ether, dissolve the product in dichloromethane, add water for extraction, collect the dichloromethane phase, and concentrate by rotary evaporation to obtain N,N-dimethylaminolysine.

[0038] Add 80 mL of isopropanol, 6 mmol of N,N-dimethylaminolysine, and 8.4 mmol of sodium 3-chloro-2-hydroxypropanesulfonate to the reaction bottle, stir and reflux at 90°C for 5 h, remove isopropanol by rotary evaporation, wash with petroleum ether, and recrystallize the product with acetone to obtain lysine betaine.

[0039] Add 100 mL of acetonitrile, 15 mmol of potassium carbonate, 8 mmol of perfluorononenyloxybenzenesulfonyl chloride, and 9.6 mmol of 1,7-bis-tert-butyloxycarbonyldiethylenetriamine to a reaction bottle, reflux at 80°C for 6 h, cool, remove acetonitrile by rotary evaporation, wash with water, dissolve the product in 50 mL of dichloromethane, add 10 mL of trifluoroacetic acid, stir at room temperature for 4 h, remove the solvent by rotary evaporation, wash with water, dissolve the product in dichloromethane, add water for extraction, collect the dichloromethane phase, and concentrate by rotary evaporation to obtain perfluorononenyloxybenzenesulfonyldiethylenetriamine;

[0040] Add 120 mL of tetrahydrofuran, 10 mmol of hexamethylene diisocyanate, 1.5 mmol of perfluorononenyloxybenzenesulfonyl diethylenetriamine, and 8.5 mmol of lysine betaine into a reaction bottle, stir and reflux at 75°C for 3 h, remove tetrahydrofuran by rotary evaporation, wash with ethanol, and obtain a betaine-type surfactant.

[0041] Example 4

[0042] Add 7 mL of dichloromethane, 6 mmol of 2,6-di-tert-butyloxycarbonylaminocaproic acid, 5.4 mmol of N,N-dimethylethylenediamine, 6.5 mmol of N,N-dicyclohexylcarbodiimide, and 6.5 mmol of 1-hydroxybenzotriazole to the reaction bottle, stir and react at 30°C for 10 h, remove dichloromethane by rotary evaporation, wash with petroleum ether, dissolve the product in 50 mL of dichloromethane, add 6 mL of trifluoroacetic acid, stir at room temperature for 3 h, remove the solvent by rotary evaporation, wash with petroleum ether, dissolve the product in dichloromethane, add water for extraction, collect the dichloromethane phase, and concentrate by rotary evaporation to obtain N,N-dimethylaminolysine.

[0043] Add 50 mL of isopropanol, 6 mmol of N,N-dimethylaminolysine, and 6 mmol of sodium 3-chloro-2-hydroxypropanesulfonate to the reaction bottle, stir and reflux at 90°C for 10 h, remove isopropanol by rotary evaporation, wash with petroleum ether, and recrystallize the product with acetone to obtain lysine betaine.

[0044] Add 80 mL of chloroform, 15 mmol of potassium carbonate, 8 mmol of perfluorononenyloxybenzenesulfonyl chloride, and 11.2 mmol of 1,7-bis-tert-butyloxycarbonyldiethylenetriamine to the reaction bottle, reflux at 80°C for 4 h, cool, remove acetonitrile by rotary evaporation, wash with water, dissolve the product in 50 mL of dichloromethane, add 10 mL of trifluoroacetic acid, stir at room temperature for 3 h, remove the solvent by rotary evaporation, wash with water, dissolve the product in dichloromethane, add water for extraction, collect the dichloromethane phase, and concentrate by rotary evaporation to obtain perfluorononenyloxybenzenesulfonyldiethylenetriamine;

[0045] Add 150 mL of tetrahydrofuran, 10 mmol of hexamethylene diisocyanate, 2 mmol of perfluorononenyloxybenzenesulfonyl diethylenetriamine, and 8 mmol of lysine betaine into a reaction bottle, stir and reflux at 70°C for 2 h, remove tetrahydrofuran by rotary evaporation, wash with ethanol, and obtain a betaine-type surfactant.

[0046] Comparative Example 1

[0047] Add 100 mL of tetrahydrofuran, 10 mmol of hexamethylene diisocyanate, and 10 mmol of lysine betaine (prepared in the same manner as in Example 1) into a reaction flask, stir and reflux at 65° C. for 3 h, remove tetrahydrofuran by rotary evaporation, and wash with ethanol to obtain a surfactant.

[0048] Comparative Example 2

[0049] Lysine betaine was used as a surfactant (the preparation method was the same as that in Example 1).

[0050] Comparative Example 3

[0051] Perfluorononenyloxybenzenesulfonyl diethylenetriamine was used as a surfactant (the preparation method was the same as that in Example 1).

[0052] The surfactants prepared in the examples and comparative examples were respectively added to deionized water to prepare solutions of different concentrations, stirred evenly at 60° C. at a stirring rate of 500 r / min, and the viscosity of the solutions was measured.

[0053] Table 1 Viscosity test table of surfactants in deionized water

[0054]

[0055] The surfactant was added into the formation mineralized water (pH of the mineralized water was 7.96 and the mineralization degree was 10413 mg / L) to prepare solutions of different concentrations. The solutions were stirred evenly at 60°C and the stirring rate was 500 r / min, and the viscosity of the solutions was measured.

[0056] Table 2 Viscosity test table of surfactants in mineralized water

[0057]

[0058]

[0059] The surfactant was added to deionized water to prepare a 1000 mg / L solution, stirred evenly at 60°C at a stirring rate of 500 r / min, and the viscosity of the solution was measured; then sheared for 30 seconds using a Wu Yin stirrer, the solution viscosity was tested, and the shear viscosity retention rate was calculated.

[0060] Table 3 Shear viscosity retention rate test table of surfactants in deionized water

[0061]

[0062] The surfactant was added to the formation mineralized water (the pH of the mineralized water was 7.96 and the mineralization degree was 10413 mg / L) to prepare a 1000 mg / L solution, stirred evenly at 60°C with a stirring rate of 500 r / min, and the viscosity of the solution was measured; then sheared for 30 seconds using a Wu Yin stirrer, the solution viscosity was tested, and the shear viscosity retention rate was calculated.

[0063] Table 4 Shear viscosity retention rate test table of surfactants in mineralized water

[0064]

[0065]

[0066] The surfactant was added into deionized water and stirred to dissolve. Solutions of different concentrations were prepared and the oil-water interfacial tension between the surfactant and crude oil was measured by the spinning drop method.

[0067] Table 5 Oil-water interfacial tension test Table 1

[0068]

[0069] The surfactant was added into the formation mineralized water (pH of the mineralized water was 7.96 and the mineralization degree was 10413 mg / L), stirred to dissolve, and solutions of different concentrations were prepared. The oil-water interfacial tension between the surfactant and the crude oil was determined by the spinning drop method.

[0070] Table 6 Oil-water interfacial tension test Table 2

[0071]

[0072] Use a core holder to clamp the natural core, add crude oil and fully saturate it, place it at 60℃ for 12 hours; continuously inject formation mineral water to carry out water flooding until the water content of the output fluid is about 98%, then inject an aqueous solution containing a surfactant (concentration of 100-1000g / L) as an oil displacement agent, and carry out surfactant flooding until the water content of the output fluid is 100%. Record the oil displacement efficiency.

[0073] Table 7 Oil displacement efficiency test table

[0074]

[0075]

[0076] The above is a description of the relevant contents of the embodiments of the inventions provided in this specification. Based on these descriptions, a person of ordinary skill in the art will be able to implement the embodiments of the inventions provided in this specification. Based on the above contents of the embodiments of the inventions provided in this specification, all other preferred implementations and embodiments obtained by a person of ordinary skill in the art without making any creative work shall fall within the scope of protection of the embodiments of the inventions provided in this specification.

Claims

1. A method for preparing a betaine-type surfactant as an oil displacement agent for high-salinity and low-permeability oil reservoirs, characterized in that: The preparation method of the betaine type surfactant is: S1. Add solvent, potassium carbonate, perfluorononenyloxybenzenesulfonyl chloride and 1,7-bis-tert-butyloxycarbonyldiethylenetriamine to a reaction flask, reflux at 75-85°C for 4-8h, cool, rotary evaporate, wash with water, dissolve the product in dichloromethane, add trifluoroacetic acid, stir at room temperature for 2-4h, rotary evaporate, wash with water, extract to obtain perfluorononenyloxybenzenesulfonyldiethylenetriamine; S2, adding tetrahydrofuran, hexamethylene diisocyanate, perfluorononenyloxybenzenesulfonyl diethylenetriamine, and lysine betaine to a reaction bottle, stirring for reaction, rotary evaporation, and washing to obtain a betaine-type surfactant as an oil displacement agent for high-salinity and low-permeability oil reservoirs; The ratio of hexamethylene diisocyanate, perfluorononenyloxybenzenesulfonyl diethylenetriamine and lysine betaine in S2 is 1 mol: (0.04-0.2) mol: (0.8-0.96) mol; The structural formula of the lysine betaine is 2. The method for preparing a betaine-type surfactant as an oil-displacing agent for high-salinity and low-permeability oil reservoirs according to claim 1, characterized in that: The solvent in S1 includes dichloromethane, chloroform, acetonitrile or tetrahydrofuran.

3. The method for preparing a betaine-type surfactant as an oil-displacing agent for high-salinity and low-permeability oil reservoirs according to claim 1, characterized in that: The ratio of potassium carbonate, perfluorononenyloxybenzenesulfonyl chloride and 1,7-bis-tert-butyloxycarbonyldiethylenetriamine in S1 is (1.5-2.5) mol: 1 mol: (1.1-1.4) mol.

4. The method for preparing a betaine-type surfactant as an oil-displacing agent for high-salinity and low-permeability oil reservoirs according to claim 1, characterized in that: The reaction in S2 is refluxed at 65-75° C. for 2-4 h.

5. The method for preparing a betaine-type surfactant as an oil-displacing agent for high-salinity and low-permeability oil reservoirs according to claim 1, characterized in that: The preparation method of the lysine betaine is: S11, add dichloromethane, 2,6-di-tert-butyloxycarbonylaminocaproic acid, N,N-dimethylethylenediamine, N,N-dicyclohexylcarbodiimide, and 1-hydroxybenzotriazole to a reaction bottle, stir and react at 25-40°C for 6-12 hours, rotary evaporate, wash, dissolve the product in dichloromethane, add trifluoroacetic acid, stir at room temperature for 2-4 hours, rotary evaporate, wash, extract, and obtain N,N-dimethylaminolysine; S12. Add isopropanol, N,N-dimethylaminolysine and sodium 3-chloro-2-hydroxypropanesulfonate into the reaction bottle, and after the reaction, perform rotary evaporation, wash and recrystallize to obtain lysine betaine.

6. The method for preparing a betaine-type surfactant as an oil-displacing agent for high-salinity and low-permeability oil reservoirs according to claim 5, characterized in that: The ratio of 2,6-di-tert-butoxycarbonylaminocaproic acid, N,N-dimethylethylenediamine, N,N-dicyclohexylcarbodiimide and 1-hydroxybenzotriazole in S11 is 1 mol:(0.9-1.2) mol:(1-1.2) mol:(1-1.2) mol.

7. The method for preparing a betaine-type surfactant as an oil-displacing agent for high-salinity and low-permeability oil reservoirs according to claim 5, characterized in that: The ratio of N,N-dimethylaminolysine to sodium 3-chloro-2-hydroxypropanesulfonate in S12 is 1 mol:(1-1.4) mol.

8. The method for preparing a betaine-type surfactant as an oil-displacing agent for high-salinity and low-permeability oil reservoirs according to claim 5, characterized in that: The reaction in S12 is refluxed at 80-90° C. for 5-10 h.

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