Preparation method and application of one-dose multi-effect alkynyl oil-displacing agent

Abstract

The invention belongs to the technical field of oil displacement agents for oil fields, and relates to a preparation method and application of a one-dose multi-effect alkynyl type oil displacement agent. An intermediate mixture solution is obtained through an alkylation reaction, the intermediate mixture solution and propyne chloride are subjected to a quaternization reaction to obtain an alkynyl sulphobetaine crude product, and the alkynyl sulphobetaine crude product is subjected to a one-dose multi-effect alkynyl type oil displacement agent. And desalting the crude product, and treating to obtain the purified long-chain alkyl propargyl sulphobetaine. The long-chain alkyl propargyl sulphobetaine disclosed by the invention effectively overcomes the problems of long dynamic interfacial tension balance time and poor oil displacement effect in a general heavy oil reservoir oil displacement agent system. After the one-dose multi-effect alkynyl type oil-displacing agent working solution is aged for 30 days at 90 DEG C, the interfacial tension of the oil-displacing agent working solution and crude oil is less than or equal to 5.0 * 10 <-3 > mN / m, the viscosity reduction rate is greater than or equal to 90%, the indoor enhanced recovery rate is greater than or equal to 30%, and the application prospect is wide.

Description

Technical Field

[0001] The invention belongs to the technical field of oil field oil displacement agents, and in particular relates to a preparation method and application of a one-dose multi-effect acetyl-based oil displacement agent. Background Art

[0002] Due to the complex environment of underground oil reservoirs, many oil reservoirs are under the "three highs" conditions of high temperature, high mineralization, and high calcium and magnesium ions, and the crude oil has high colloid and asphaltene content and high crude oil viscosity. Shengli Oilfield has very rich geological resources for heavy oil reservoirs. For ordinary heavy oil with underground crude oil viscosity <1000mPa·s, water injection development is currently mostly used. Due to the high viscosity of crude oil, the large difference in water-oil mobility ratio, the serious fingering phenomenon of water drive, the small sweep coefficient, and the average recovery rate of only 15.5%, according to the characteristics of this type of oil reservoir, how to improve the recovery rate of crude oil economically and efficiently is a very urgent problem to be solved.

[0003] Dongxin Oilfield in Shengli Oilfield is suitable for chemical flooding. Compared with Gudao, Gudong and Shengcai, its reservoir obviously has many unfavorable factors, which are mainly manifested in high reservoir temperature, high crude oil viscosity, high comprehensive water content, tight fresh water resources, high mineralization of injected wastewater, severe dynamic heterogeneity such as large pores, conventional well network and poor well conditions.

[0004] Yong 8 block is the key production capacity block of Dongxin Oilfield. However, due to the serious heterogeneity of the layer and the heavy oil in the block, the chemical structure of conventional oil displacement agents is easy to change under the high temperature conditions of the block, and the stability of the compound system is poor. In the oil displacement process, serious chromatographic separation is easy to occur, resulting in poor oil displacement efficiency. In the indoor evaluation, it is generally found that the ultra-low oil-water interfacial tension (≤5.0×10 -3 mN / m) and low oil washing rate.

[0005] From the perspective of sustainable and stable development of oil reservoirs, new oil recovery technologies such as chemical flooding, as effective replacement technologies for water flooding in the later stage of development, play a vital role in improving oil reservoir recovery and economic benefits. Therefore, it is of great significance to study tertiary oil recovery technology that is suitable for the reservoir conditions of Dongxin Oilfield and improve the ultimate recovery of oil reservoirs. Summary of the invention

[0006] The purpose of the present invention is to provide a preparation method and application of a one-dose multi-effect acetyl-based oil displacement agent to solve the problems of long dynamic interfacial tension equilibrium time and poor oil displacement effect in general heavy oil reservoir oil displacement agent systems.

[0007] The technical solution adopted by the present invention to solve the technical problem is: a method for preparing a one-dose multi-effect acetylene-based oil-displacing agent, comprising the following steps:

[0008] (1) Alkylation reaction:

[0009] Sodium N-methyltaurate and catalyst sodium hydroxide are dissolved in a mixed solvent of isopropanol / water, the temperature is raised to 50-80°C, an isopropanol solution of alkyl halide is added dropwise to react for 4-8 hours, and the pH is adjusted to 7.0-7.5 with sodium hydroxide to obtain an intermediate mixture solution; the intermediate molecular formula is Where R is C 12 H 25 , C 14 H 29 , C 16 H 33 , C 18 H 37 One or more of;

[0010] (2) Quaternization reaction:

[0011] A certain amount of inhibitor is added to the intermediate mixture solution, propynyl chloride is added dropwise at 50°C, and then the temperature is slowly raised to 75-80°C for reaction for 1-4 hours to obtain crude alkynyl sulfobetaine;

[0012] (3) Desalination:

[0013] The crude alkynyl sulfobetaine was filtered at 80°C to remove most of the inorganic salts, and then the isopropanol and water were removed by rotary evaporation. The solvent was heated with isopropanol again, and the inorganic salts were removed by filtration. The mixture was cooled to -10 to 0°C, and a light yellow filter cake was obtained by suction filtration. The mixture was vacuum dried at low temperature for 4 to 24 hours to obtain a purified long-chain alkyl propargyl sulfobetaine. The molecular formula of the long-chain alkyl propargyl sulfobetaine is Where R is C 12 H 25 , C 14 H 29 , C 16 H 33 , C 18 H 37 One or more of .

[0014] Furthermore, the halogenated hydrocarbon in step (1) is a mixture of one or more of dodecane bromide, tetradecane bromide, hexadecane bromide and octadecane bromide.

[0015] Furthermore, the molar ratio of the halogenated hydrocarbon to sodium N-methyltaurate in step (1) is 1:1.0-1.2.

[0016] Furthermore, the molar ratio of the catalyst sodium hydroxide to the halogenated hydrocarbon substance in the step (1) is 0.05-0.2:1.0.

[0017] Furthermore, the molar ratio of propynyl chloride to halogenated hydrocarbon in step (2) is 1.0:1.0-1.1.

[0018] Furthermore, the polymerization inhibitor in step (2) is 2-tert-butylhydroquinone, and the amount added relative to propynyl chloride is 25 to 100 ppm.

[0019] The application of a multi-effect alkynyl oil displacement agent prepared by the above preparation method is to prepare a 0.05-0.3wt% oil displacement working fluid with long-chain alkyl propargyl sulfobetaine on-site water.

[0020] Furthermore, after the oil displacement agent working fluid is aged at 90°C for 30 days, the interfacial tension between the oil displacement agent working fluid and the crude oil is ≤5.0×10 -3 mN / m, viscosity reduction rate ≥90%, indoor enhanced oil recovery rate ≥30%.

[0021] The present invention has the following beneficial effects:

[0022] The present invention uses molecular design methods, alkylation reactions, and quaternization reactions to prepare sulfobetaine containing alkynyl groups. After entering the formation, the alkynyl groups have a high electron cloud density, which can produce intermolecular π-π conjugation to form a gemini surfactant-like structure, effectively increase dynamic interfacial activity, and reduce the time required to reach ultra-low interfacial tension, thereby having better dynamic interfacial tension and wetting and spreading performance, and achieving efficient crude oil wetting, stripping, and emulsification and viscosity reduction oil recovery effects. The long-chain alkyl propargyl sulfobetaine of the present invention effectively overcomes the problems of long dynamic interfacial tension equilibrium time and poor oil recovery effect in general heavy oil reservoir oil recovery agent systems. After aging at 90°C for 30 days, the interfacial tension between the oil recovery agent working fluid and the crude oil is ≤5.0×10 -3 mN / m, viscosity reduction rate ≥90%, indoor enhanced oil recovery rate ≥30%, with broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a dynamic diagram of the oil-water interfacial tension before and after aging of Example 4 in Application Example 1 of the present invention.

[0024] Figure 2 It is a dynamic diagram of oil-water interfacial tension before and after aging of the conventional betaine-type oil-displacing agent in Application Example 1 of the present invention. DETAILED DESCRIPTION

[0025] The following are specific embodiments of the present invention, which further describe the technical solution of the present invention, but the protection scope of the present invention is not limited to these embodiments. Any changes or equivalent substitutions that do not deviate from the concept of the present invention are included in the protection scope of the present invention.

[0026] Example 1

[0027] (1) Alkylation reaction

[0028] In a 250 mL single-necked round-bottom flask, 16.1 g (100 mmol) of sodium N-methyltaurine, 30.0 g of isopropanol, 15.0 g of deionized water and 0.2 g of sodium hydroxide were added. Magnetic stirring was turned on, and the oil bath was heated to 70° C. Reflux was turned on. A solution of 24.9 g (100 mmol) of dodecane bromide and 25 g of isopropanol was added dropwise. The addition was completed in 1 h. The reaction was continued at 70° C. for 6 h. Sodium hydroxide was added to adjust the pH to 7.2 to obtain an intermediate mixture solution.

[0029] (2) Quaternization reaction

[0030] In the intermediate mixture solution, add 0.37 g of 0.1% isopropanol solution of 2-tert-butylhydroquinone (the amount of propynyl chloride added is 50 ppm), turn on magnetic stirring and heat to 50°C, add 7.45 g (100 mmol) of propynyl chloride, slowly raise the temperature to 80°C within 1 hour, and continue the reaction for 1 hour to obtain crude alkynyl sulfobetaine.

[0031] (3) Desalination

[0032] The crude alkynyl sulfobetaine was filtered at 80°C to remove most of the inorganic salts, and then transferred to a rotary evaporator to remove isopropanol and water. The solvent was then heated with isopropanol again and the inorganic salts were removed by filtration. The mixture was cooled to -8°C and filtered to obtain a light yellow filter cake, which was then dried under low temperature vacuum for 18 hours to obtain 32.5 g of purified dodecane propargyl sulfobetaine.

[0033] Example 2

[0034] (1) Alkylation reaction

[0035] In a 250mL single-mouth round-bottom flask, 17.7g (110mmol) of sodium N-methyltaurine, 30.0g of isopropanol, 20.0g of deionized water and 0.6g of sodium hydroxide were added. The magnetic stirring was turned on, and the oil bath was heated to 80°C. The reflux was turned on, and a solution of 11.5g (60mmol) of dodecane bromide, 11.0g (40mmol) of tetradecane bromide, and 25g of isopropanol was added dropwise. The addition was completed in 1 hour, and the reaction was continued at 80°C for 4 hours. Sodium hydroxide was added to adjust the pH to 7.28 to obtain an intermediate mixed solution.

[0036] (2) Quaternization reaction

[0037] In the intermediate mixed solution, add 0.61 g of 0.1% mass fraction of 2-tert-butylhydroquinone isopropanol solution (the amount of propynyl chloride added is 78 ppm), turn on magnetic stirring and heat to 50°C, add 7.82 g (105 mmol) of propynyl chloride, slowly raise the temperature to 75°C within 1 hour, and continue the reaction for 3 hours to obtain crude alkynyl sulfobetaine.

[0038] (3) Desalination

[0039] The crude alkynyl sulfobetaine was filtered at 80°C to remove most of the inorganic salts, and then transferred to a rotary evaporator to remove isopropanol and water. The solvent was then heated with isopropanol again and the inorganic salts were removed by filtration. The product was cooled to -5°C and filtered to obtain a light yellow filter cake which was then dried under low temperature vacuum for 4 hours to obtain 33.7 g of purified dodeca / tetradecane propargyl sulfobetaine.

[0040] Example 3

[0041] (1) Alkylation reaction

[0042] In a 250mL single-necked round-bottom flask, 16.9g (105mmol) of sodium N-methyltaurine, 30.0g of isopropanol, 15.0g of deionized water and 0.4g of sodium hydroxide were added. Magnetic stirring was turned on, and the oil bath was heated to 75°C. Reflux was turned on, and a solution of 24.4g (80mmol) of hexadecane bromide, 6.7g (20mmol) of octadecane bromide, and 30g of isopropanol was added dropwise. The addition was completed in 1 hour, and the reaction was continued at 75°C for 6 hours. Sodium hydroxide was added to adjust the pH to 7.0 to obtain an intermediate mixed solution.

[0043] (2) Quaternization reaction

[0044] In the intermediate mixed solution, add 0.205 g of 0.1% mass fraction of 2-tert-butylhydroquinone isopropanol solution (relative to the amount of propynyl chloride added is 25 ppm), turn on magnetic stirring and heat to 50 ° C, add 8.2 g (110 mmol) of propynyl chloride, slowly heat to 75 ° C within 1 hour, and continue to react for 4 hours to obtain crude alkynyl sulfobetaine.

[0045] (3) Desalination

[0046] The crude alkynyl sulfobetaine was filtered at 80°C to remove most of the inorganic salts, and then transferred to a rotary evaporator to remove isopropanol and water. The solvent was then heated with isopropanol again, and the inorganic salts were removed by filtration. The mixture was cooled to -10°C, and the light yellow filter cake was filtered and dried under low temperature vacuum for 16 hours to obtain 36.5 g of purified hexadecane / octadecane propargyl sulfobetaine.

[0047] Example 4

[0048] (1) Alkylation reaction

[0049] In a 250mL single-necked round-bottom flask, 17.7g (110mmol) of sodium N-methyltaurine, 30.0g of isopropanol, 20.0g of deionized water and 0.8g of sodium hydroxide were added. Magnetic stirring was turned on, and the oil bath was heated to 50°C. Reflux was turned on, and a solution of 12.5g (50mmol) of dodecane bromide, 6.9g (25mmol) of tetradecane bromide, 7.6g (25mmol) of hexadecane bromide, and 30g of isopropanol was added dropwise. The addition was completed in 1 hour, and the reaction was continued at 50°C for 8 hours. Sodium hydroxide was added to adjust the pH to 7.5 to obtain an intermediate mixed solution.

[0050] (2) Quaternization reaction

[0051] In the intermediate mixed solution, add 0.82 g of 0.1% mass fraction of 2-tert-butylhydroquinone isopropanol solution (relative to the amount of propynyl chloride added is 100 ppm), turn on magnetic stirring and heat to 50°C, add 8.2 g (110 mmol) of propynyl chloride, slowly heat to 78°C within 1 hour, and continue the reaction for 2 hours to obtain crude alkynyl sulfobetaine.

[0052] (3) Desalination

[0053] The crude alkynyl sulfobetaine was filtered at 80°C to remove most of the inorganic salts, and then transferred to a rotary evaporator to remove isopropanol and water. The solvent was then heated with isopropanol again, and the inorganic salts were filtered off. The mixture was cooled to 0°C, and the light yellow filter cake was filtered off and dried under low temperature vacuum for 24 hours to obtain 34.4 g of purified dodeca / tetradecane / hexadecane propargyl sulfobetaine.

[0054] The application process of the multi-effect acetylene-based oil-displacing agent provided by the present invention is as follows.

[0055] Application Example 1

[0056] The long-chain alkyl alkynyl sulfobetaine prepared in Examples 1 to 4 was injected with water (mineralization 29117 mg / L, Ca 2+ +Mg 2+ :1434mg / L,) prepare 0.05~0.3wt% alkynyl sulfobetaine flooding agent working fluid, age it in a hydrothermal synthesis reactor at reservoir temperature 90℃ for 30 days, test the oil-water interfacial tension before and after aging and record the value of 10 -3 The time required for the oil-water interfacial tension to reach the mN / m level is shown in Table 1. The dynamic diagram of the oil-water interfacial tension before and after aging in Example 4 is shown in Figure 1 As shown in the figure, the dynamic diagram of oil-water interfacial tension before and after aging of conventional betaine-based oil displacement agent is as follows Figure 2 shown.

[0057] Table 1 Oil-water interfacial tension before and after aging and record 10 -3mN / m order of magnitude required timetable

[0058]

[0059] Application Example 2

[0060] The long-chain alkyl alkynyl sulfobetaine prepared in Examples 1 to 4 was used to prepare an oil displacement agent working fluid with a concentration of 0.05 to 0.3 wt % using the injection water prepared at the construction site, and aged for 24 h at the reservoir temperature using a hydrothermal synthesis reactor. The aged fluid was then mixed with ordinary heavy oil at an oil-water mass ratio of 8:2 to test the viscosity reduction effect before and after aging. The results are shown in Table 2.

[0061] Table 2 Statistical table of viscosity reduction effect before and after aging

[0062]

[0063] Application Example 3

[0064] The long-chain alkyl alkynyl sulfobetaine prepared in Examples 1 to 4 was used to prepare an oil displacement agent working fluid with a concentration of 0.05 to 0.3 wt % using the injection water prepared on site, and aged for 24 h at reservoir temperature using a hydrothermal synthesis reactor. The aged fluid was then subjected to a core displacement experiment. The results of the indoor enhanced oil recovery are shown in Table 3.

[0065] Table 3 Statistics of indoor enhanced oil recovery

[0066]

[0067] Application Example 4

[0068] The long-chain alkyl alkynyl sulfobetaine prepared in Examples 1 to 4 was used to prepare an oil displacement agent working fluid with a concentration of 0.05 to 0.3 wt % using the injection water prepared at the construction site. The oil washing efficiency was tested after aging for 24 hours. The results are shown in Table 4.

[0069] Table 4 Oil washing rate statistics

[0070]

[0071]

[0072] The present invention is not limited to the above-mentioned implementation modes, and anyone should be aware of the structural changes made under the enlightenment of the present invention, and all those having the same or similar technical solutions as the present invention fall within the protection scope of the present invention.

[0073] The techniques, shapes, and structural parts not described in detail in the present invention are all well-known techniques.

Claims

1. A method for preparing a one-dose multi-effect acetylene-based oil-displacing agent, characterized in that: The following steps are involved: (1) Alkylation reaction: Dissolve sodium N-methyltaurate and catalyst sodium hydroxide in a mixed solvent of isopropanol / water, heat to 50-80° C., dropwise add an isopropanol solution of alkyl halide to react for 4-8 hours, and adjust the pH to 7.0-7.5 with sodium hydroxide to obtain an intermediate mixture solution; (2) Quaternization reaction: A certain amount of inhibitor is added to the intermediate mixture solution, propynyl chloride is added dropwise at 50°C, and then the temperature is slowly raised to 75-80°C for reaction for 1-4 hours to obtain crude alkynyl sulfobetaine; (3) Desalination: The crude alkynyl sulfobetaine was filtered at 80°C to remove most of the inorganic salts, and then the isopropanol and water were removed by rotary evaporation. The solvent was then heated with isopropanol again, and the inorganic salts were removed by filtration. The product was cooled to -10 to 0°C, and a light yellow filter cake was obtained by suction filtration. The product was vacuum dried at low temperature for 4 to 24 hours to obtain purified long-chain alkyl propargyl sulfobetaine.

2. The method for preparing a multi-effect acetylene-based oil-displacing agent according to claim 1, characterized in that: The halogenated hydrocarbon in step (1) is a mixture of one or more of dodecane bromide, tetradecane bromide, hexadecane bromide and octadecane bromide.

3. The method for preparing a multi-effect acetylene-based oil-displacing agent according to claim 1, characterized in that: The molar ratio of the halogenated hydrocarbon to sodium N-methyltaurate in step (1) is 1:1.0-1.

2.

4. The method for preparing a multi-effect acetylene-based oil-displacing agent according to claim 1, characterized in that: The molar ratio of the catalyst sodium hydroxide to the halogenated hydrocarbon substance in the step (1) is 0.05-0.2:1.

0.

5. The method for preparing a multi-effect acetylene-based oil-displacing agent according to claim 1, characterized in that: The molar ratio of propynyl chloride to halogenated hydrocarbon in step (2) is 1.0-1.1:1.

0.

6. The method for preparing a multi-effect acetylene-based oil-displacing agent according to claim 1, characterized in that: The polymerization inhibitor in step (2) is 2-tert-butylhydroquinone, and the amount added relative to propynyl chloride is 25 to 100 ppm.

7. An application of a multi-effect acetylene-based oil-displacing agent prepared by the preparation method according to any one of claims 1 to 6, characterized in that: The long-chain alkyl propargyl sulfobetaine on-site water is prepared into an oil displacement working fluid with a concentration of 0.05-0.3 wt%.

8. The use of a multi-effect acetylene-based oil-displacing agent as claimed in claim 7, characterized in that: After the oil displacement agent working fluid is aged at 90°C for 30 days, the interfacial tension between the oil displacement agent working fluid and crude oil is ≤5.0×10 -3 mN / m, viscosity reduction rate ≥90%, indoor enhanced oil recovery rate ≥30%.

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