Gemini anionic organic alkali surfactant as well as preparation method and application thereof

Abstract

The invention relates to the technical field of ternary combination flooding in tertiary oil recovery, in particular to a gemini anionic organic alkali surfactant as well as a preparation method and application thereof. The preparation method comprises the following steps: in the presence of NaOH, carrying out contact reaction on an N-tallow triamine alcohol solution and a 3-chloro-2-hydroxy sodium propanesulfonate aqueous solution to obtain a first mixed solution; distilling and drying the first mixed solution to obtain an intermediate; dissolving the intermediate in water to obtain an aqueous solution containing the intermediate; in the presence of NaOH, the aqueous solution of the intermediate and the dibromoethane alcohol solution are subjected to a contact reaction, and a second mixed solution is obtained; and distilling and drying the second mixed solution to obtain the organic alkali surfactant. When the organic alkali surfactant provided by the invention is used for ASP flooding, the recovery rate of remaining oil can be increased by 22.5%; the synthesis method is easy to operate, raw materials, intermediates and products do not contain toxic substances, and the products do not contain halogen, so that the synthesis method is environment-friendly.

Description

Technical Field

[0001] The invention relates to the technical field of tertiary oil recovery, and in particular to a gemini anionic organic alkaline surfactant, a preparation method and application thereof. Background Art

[0002] With the continuous deepening of water flooding development in oil reservoirs, most of my country's oil reservoirs have entered the high water content stage, and the remaining oil in the reservoir cannot be effectively mined and utilized. In order to improve the oil recovery rate after water flooding in oil reservoirs, many researchers at home and abroad have conducted in-depth research on the ternary composite flooding system with alkali / surfactant / polymer (ASP) as a tertiary oil recovery technology.

[0003] Inorganic bases such as NaOH and Na2CO3 are widely used in ternary composite flooding systems, but inorganic bases are very easy to react with high-valent cations in formation water and rocks to form scale and block reservoirs. Compared with inorganic bases, organic bases are weaker in alkalinity and have weaker interactions with high-valent metal ions in the formation, but their reactions with petroleum acids in crude oil are very similar to those of inorganic bases. Therefore, the research of new and efficient organic base ternary composite flooding is an urgent problem to be solved in the field of tertiary oil recovery.

[0004] Surfactants in ASP flooding are usually single-chain surfactants, which require large dosages and have very limited performance compared to Gemini surfactants. Gemini surfactants containing two hydrophilic groups and a hydrophobic group have better surface activity and lower critical micelle concentration. Among them, anionic Gemini surfactants have small adsorption losses and strong synergistic effects, and can be compounded to improve performance and reduce dosage.

[0005] Chinese patent application CN115710205A discloses "Gemini anionic surfactant and its preparation method, high temperature resistant surfactant composition and oil reservoir flooding method", reporting a method for preparing a gemini anionic surfactant containing a hydrophilic group of sulfonic acid or carboxylic acid. The surfactant has strong temperature resistance and excellent surface activity, and can meet the requirements of temperature resistance, salt resistance, calcium and magnesium resistance. However, the raw materials used in the surfactant are highly toxic, and the main raw material structure contains benzene rings, which may cause harm to the formation water body. The metal ions such as barium, magnesium, and calcium in the product structure may precipitate and block the reservoir under formation conditions.

[0006] Chinese patent application CN103937480A discloses "An organic base / surfactant binary composite oil recovery system and its preparation method and application", reporting a preparation method of an organic base / surfactant binary composite oil recovery system, which has excellent ability to reduce oil-water interfacial tension. However, the organic base in this system needs to be compounded with the surfactant, and the amount of organic base used is relatively large.

[0007] Therefore, the existing technology has the problems that the synthetic raw materials or products are not environmentally friendly, may block the reservoir under formation conditions, and the amount of organic base used in the ternary composite flooding system is large. Summary of the invention

[0008] The purpose of the present invention is to provide a gemini anionic organic alkaline surfactant, a preparation method and an application thereof, so as to overcome the problems in the prior art that the inorganic alkali in the ternary composite flooding is easy to scale and block the reservoir, is unfriendly to the environment, has a large oil-water interfacial tension and the recovery rate of the residual oil is not ideal.

[0009] In order to achieve the above object, the technical solution provided by the present invention is: a polyamine type gemini anionic organic alkaline surfactant is a compound having a structure as shown in formula (I):

[0010]

[0011] Wherein, n is 2, 3, and 4, and the corresponding raw materials are dibromoethane, 1,3-dibromopropane, and 1,4-dibromobutane. Further, the preparation method of the above-mentioned polyamine gemini anionic organic alkaline surfactant comprises the following steps:

[0012] (1) dissolving a first raw material in a solvent to obtain an alcohol solution containing the first raw material; wherein the first raw material is N-tallow triamine and the solvent is isopropanol;

[0013] (2) dissolving the second raw material in a solvent to obtain an aqueous solution containing the second raw material; wherein the second raw material is sodium 3-chloro-2-hydroxypropanesulfonate and the solvent is deionized water;

[0014] (3) contacting an alcohol solution containing the first raw material and an aqueous solution containing the second raw material in the presence of an alkaline catalyst to obtain a first mixed solution;

[0015] (4) The first mixed solution is sequentially subjected to distillation treatment and drying treatment to obtain an intermediate.

[0016] (5) dissolving the intermediate obtained in step (4) in a solvent to obtain an aqueous solution containing the intermediate; wherein the solvent is deionized water;

[0017] (6) dissolving the third raw material in a solvent to obtain an alcohol solution containing the third raw material, wherein the third raw material is ethylene dibromide and the solvent is ethanol;

[0018] (7) contacting the aqueous solution containing the intermediate and the alcohol solution containing the third raw material in the presence of a basic catalyst to obtain a second mixed solution;

[0019] (8) The second mixed solution is sequentially subjected to distillation treatment and drying treatment to obtain a product.

[0020] Furthermore, in the above step (1), the weight ratio of the first raw material to isopropanol is 1:5-6.

[0021] Furthermore, in the above step (7), the molar ratio of the third raw material, the alkaline catalyst and the intermediate is 1-1.2:2:2.

[0022] Furthermore, in the above step (6), the weight ratio of the third raw material to the ethanol is 1:20-25.

[0023] Furthermore, in the above step (3), the molar ratio of the second raw material, the alkaline catalyst, and the first raw material is 3.7-4:1:3.33-3.5.

[0024] Furthermore, in the above step (2), the weight ratio of the second raw material to the water is 1:3-4; in step (5), the weight ratio of the intermediate to the water is 1:3.5-4.

[0025] Furthermore, the above organic alkaline surfactant is used in ASP flooding in oil fields.

[0026] Compared with the prior art, the advantages of the present invention are:

[0027] 1. Since the raw material is octadecyldipropylenetriamine, which has a certain alkalinity and a long-chain alkyl group, based on the structure of the raw material, the present invention introduces a hydrophilic group on the basis of the raw material to make it have the properties of an organic base and a surfactant. The organic base surfactant provided by the present invention has good compatibility with formation water, can react with petroleum acid substances in crude oil to generate substances with surface activity, and has good surface activity itself. The two work together to effectively reduce the oil-water interfacial tension, and can achieve the effect of "one dose for two purposes" in ternary composite flooding. The organic base surfactant provided by the present invention is used in ternary composite flooding to increase the recovery rate of residual oil by 22.5%.

[0028] 2. The present invention organically combines an organic base and a surfactant, uses octadecyldipropylenetriamine and sodium 3-chloro-2-hydroxypropanesulfonate as raw materials to undergo a substitution reaction, thereby introducing a sulfonic acid group, and then uses dibromoethane as a linking group to undergo secondary substitution to generate a gemini organic base surfactant. The synthesis method is easy to operate, and since the raw materials, intermediates, and products do not contain toxic substances, and the product does not contain halogens, it is relatively environmentally friendly.

[0029] 3. Replace the traditional inorganic base with an organic base, and organically combine the organic base with a surfactant to synthesize a polyamine surfactant having both organic base properties and surfactant properties. The organic base surfactant contained in the present invention is mainly used in the field of ternary composite flooding of tertiary oil recovery to replace the traditional inorganic base and surfactant to achieve the effect of "one dose for two purposes". Therefore, the present invention synthesizes a gemini anionic surfactant that can reduce the oil-water interfacial tension and has the properties of an organic base, in order to achieve the effect of "one dose for two purposes" in ternary composite flooding. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a physical picture of an organic alkaline surfactant prepared using dibromoethane and Example 1 of the present invention;

[0031] Figure 2 This is a physical picture of the dissolution of the organic alkaline surfactant prepared by using dibromoethane and Example 1 of the present invention in water;

[0032] Figure 3 The infrared spectra of the intermediate and the organic base surfactant prepared by using dibromoethane and Example 1 of the present invention are shown in FIG. DETAILED DESCRIPTION

[0033] The following is a clear and complete description of the technical solution of the present invention in combination with the embodiments of the present invention and the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] In the following examples, unless otherwise specified, all raw materials used are commercially available.

[0035] The first raw material: N-tallow triamine, purity 99%, purchased from Nantong Boya Environmental Protection Technology Co., Ltd.;

[0036] Second raw material: sodium 3-chloro-2-hydroxypropanesulfonate, purity 99%, purchased from MacLean Reagent Co., Ltd.;

[0037] The third raw material: dibromoethane, purity 99%, purchased from MacLean Reagent Co., Ltd.;

[0038] Alkaline catalyst: Sodium hydroxide, purity 99%, purchased from MacLean Reagent Co., Ltd.

[0039] In the present invention, unless otherwise specified, the room temperature or normal temperature refers to 25±2°C.

[0040] Example 1

[0041] This embodiment provides a method for synthesizing an organic alkaline surfactant, the method comprising the following steps:

[0042] (1) 13 g of N-tallow triamine was placed in a three-necked flask, and isopropanol was added in a weight ratio of 1:5 to N-tallow triamine, and the mixture was stirred until the mixture was completely dissolved to obtain an N-tallow triamine alcohol solution.

[0043] (2) dissolving 8 g of sodium 3-chloro-2-hydroxypropanesulfonate in 20 mL of water and stirring until completely dissolved to obtain an aqueous solution of sodium 3-chloro-2-hydroxypropanesulfonate;

[0044] (3) in the presence of NaOH, contacting the N-tallow triamine alcohol solution and the sodium 3-chloro-2-hydroxypropanesulfonate aqueous solution to obtain a first mixed solution;

[0045] The molar ratio of sodium 3-chloro-2-hydroxypropanesulfonate, the sodium hydroxide and N-tallow triamine is 3.86:1:3.33.

[0046] The conditions of the contact reaction were: stirring speed of 350 rpm, temperature of 60° C., and time of 8 hours.

[0047] (4) The first mixed solution was distilled at 80° C. for 0.5 hours to remove the solvent in the three-necked flask, and then the remaining material after distillation was transferred to a beaker, and the beaker was placed in an oven at 90° C. and dried for 0.5 hours to obtain an organic base surfactant intermediate.

[0048] (5) dissolving 11 g of the intermediate in 40 mL of water to obtain an aqueous solution containing the intermediate;

[0049] (6) Dissolve 2 g of dibromoethane in 40 mL of ethanol to obtain a dibromoethane alcohol solution;

[0050] (7) contacting the aqueous solution of the intermediate with the dibromoethane alcohol solution in the presence of NaOH to obtain a second mixed solution;

[0051] Wherein, the molar ratio of dibromoethane, the sodium hydroxide and the intermediate is 1:2:2.

[0052] The conditions of the contact reaction were: stirring speed of 350 rpm, temperature of 80° C., and time of 48 hours.

[0053] (8) The second mixed solution was distilled at 80° C. for 0.5 hour to remove the solvent in the three-necked flask, and then the remaining material after distillation was transferred to a beaker, and the beaker was placed in an oven at 90° C. and dried for 0.5 hour to obtain an organic base surfactant S1.

[0054] Example 2

[0055] This embodiment provides a method for synthesizing an organic alkaline surfactant, the method comprising the following steps:

[0056] (1) 13 g of N-tallow triamine was placed in a three-necked flask, and isopropanol was added in a weight ratio of 1:5 to N-tallow triamine, and the mixture was stirred until the mixture was completely dissolved to obtain an N-tallow triamine alcohol solution.

[0057] (2) dissolving 8.5 g of sodium 3-chloro-2-hydroxypropanesulfonate in 20 mL of water and stirring until completely dissolved to obtain an aqueous solution of sodium 3-chloro-2-hydroxypropanesulfonate;

[0058] (3) in the presence of NaOH, contacting the N-tallow triamine alcohol solution and the sodium 3-chloro-2-hydroxypropanesulfonate aqueous solution to obtain a first mixed solution;

[0059] The molar ratio of sodium 3-chloro-2-hydroxypropanesulfonate, the sodium hydroxide and N-tallow triamine is 4:1:3.33.

[0060] The conditions of the contact reaction were: stirring speed of 360 rpm, temperature of 65° C., and time of 6 hours.

[0061] (4) The first mixed solution was distilled at 80° C. for 0.5 hours to remove the solvent in the three-necked flask, and then the remaining material after distillation was transferred to a beaker, and the beaker was placed in an oven at 70° C. and dried for 2.5 hours to obtain an organic base surfactant intermediate.

[0062] (5) dissolving 11 g of the intermediate in 40 mL of water to obtain an aqueous solution containing the intermediate;

[0063] (6) Dissolve 2.1 g of dibromoethane in 40 mL of ethanol to obtain a dibromoethane alcohol solution;

[0064] (7) contacting the aqueous solution of the intermediate with the dibromoethane alcohol solution in the presence of NaOH to obtain a second mixed solution;

[0065] The molar ratio of dibromoethane, the sodium hydroxide and the intermediate is 1.05:2:2.

[0066] The conditions of the contact reaction were: stirring speed of 360 rpm, temperature of 75° C., and time of 48 hours.

[0067] (8) The second mixed solution was distilled at 80° C. for 0.2 hours to remove the solvent in the three-necked flask, and then the remaining material after distillation was transferred to a beaker. The beaker was placed in an oven at 80° C. and dried for 2.5 hours to obtain an organic base surfactant S2.

[0068] Example 3

[0069] This embodiment provides a method for synthesizing an organic alkaline surfactant, the method comprising the following steps:

[0070] (1) 15 g of N-tallow triamine was placed in a three-necked flask, and isopropanol was added in a weight ratio of 1:5 to N-tallow triamine, and the mixture was stirred until the mixture was completely dissolved to obtain an N-tallow triamine alcohol solution.

[0071] (2) dissolving 8.5 g of sodium 3-chloro-2-hydroxypropanesulfonate in 20 mL of water and stirring until completely dissolved to obtain an aqueous solution of sodium 3-chloro-2-hydroxypropanesulfonate;

[0072] (3) in the presence of NaOH, contacting the N-tallow triamine alcohol solution and the sodium 3-chloro-2-hydroxypropanesulfonate aqueous solution to obtain a first mixed solution;

[0073] The molar ratio of sodium 3-chloro-2-hydroxypropanesulfonate, the sodium hydroxide and N-tallow triamine is 4:1:3.4.

[0074] The conditions for the contact reaction were: stirring speed of 380 rpm, temperature of 65° C., and time of 6 hours.

[0075] (4) The first mixed solution was distilled at 80° C. for 0.7 hours to remove the solvent in the three-necked flask, and then the remaining material after distillation was transferred to a beaker, and the beaker was placed in an oven at 75° C. and dried for 5 hours to obtain an organic base surfactant intermediate.

[0076] (5) dissolving 11 g of the intermediate in 40 mL of water to obtain an aqueous solution containing the intermediate;

[0077] (6) Dissolve 2.3 g of dibromoethane in 40 mL of ethanol to obtain a dibromoethane alcohol solution;

[0078] (7) contacting the aqueous solution of the intermediate with the dibromoethane alcohol solution in the presence of NaOH to obtain a second mixed solution;

[0079] The molar ratio of dibromoethane, the sodium hydroxide and the intermediate is 1.1:2:2.

[0080] The conditions of the contact reaction were: stirring speed of 380 rpm, temperature of 80° C., and time of 36 hours.

[0081] (8) The second mixed solution was distilled at 80° C. for 1 hour to remove the solvent in the three-necked flask, and then the remaining material after distillation was transferred to a beaker. The beaker was placed in an oven at 80° C. and dried for 5 hours to obtain an organic base surfactant S3.

[0082] Example 4

[0083] In this example, an organic alkaline surfactant is prepared according to the method of Example 3, except that in step (3), the molar ratio of sodium 3-chloro-2-hydroxypropanesulfonate, the sodium hydroxide and N-tallow triamine is 4:1:3.5.

[0084] The remaining steps are the same as those in Example 3 to obtain an organic base surfactant S4.

[0085] Example 5

[0086] In this example, an organic alkaline surfactant is prepared according to the method of Example 3, except that in step (7), the molar ratio of dibromoethane, the sodium hydroxide and the intermediate is 1.2:2:2.

[0087] The remaining steps are the same as those in Example 3 to obtain an organic base surfactant S5.

[0088] Example 6

[0089] In this example, an organic alkaline surfactant is prepared according to the method of Example 3, except that in step (3), the molar ratio of sodium 3-chloro-2-hydroxypropanesulfonate, the sodium hydroxide and N-tallow triamine is 3.86:1:3.5.

[0090] The remaining steps are the same as those in Example 3 to obtain an organic base surfactant S6.

[0091] Example 7

[0092] In this example, an organic alkaline surfactant is prepared according to the method of Example 3, except that in step (7), the contact reaction conditions are: stirring speed of 350 rpm, temperature of 60° C., and time of 48 hours.

[0093] The remaining steps are the same as those in Example 3 to obtain an organic base surfactant S7.

[0094] Example 8

[0095] In this example, an organic base surfactant is prepared according to the method of Example 3, except that in step (8), the first mixed solution is distilled for 1 hour to remove the solvent in the three-necked flask, and then the remaining material after distillation is transferred to a beaker, and the beaker is placed in an oven at 80° C. and dried for 24 hours. The remaining steps are the same as in Example 3 to obtain an organic base surfactant S8.

[0096] Test Example 1

[0097] The performance of the organic alkaline surfactants prepared in Examples 1-8 was tested, including surface tension, interfacial tension and oil displacement performance. The specific test results are shown in Table 1.

[0098] The surface tension test method is as follows: the organic alkaline surfactant in the embodiment and the comparative example is prepared into a 0.3 wt % solution with deionized water to obtain a sample to be tested, and then the sample to be tested is tested with a surface tension meter at 25° C., and the average value is obtained by continuous measurement three times;

[0099] The test method of interfacial tension is as follows: the organic alkaline surfactant in the embodiment and the comparative example is prepared into a 0.3wt% solution with deionized water to obtain a sample to be tested, and the sample is measured three times at 25°C using a TX-500C rotating drop interfacial tension meter with Xinjiang crude oil as the oil sample to obtain the average value.

[0100] Table 1

[0101] pH Surface tension, mN / m Interfacial tension, mN / m Example 1 10.52 29.2 0.008 Example 2 10.23 30.18 0.012 Example 3 10.12 30.35 0.018 Example 4 10.08 32.12 0.025 Example 5 10.07 30.72 0.036 Example 6 9.86 34.32 0.057 Example 7 9.58 33.62 0.086 Example 8 9.89 34.48 0.048

[0102] It can be seen from the results in Table 1 that the organic alkaline surfactant provided by the present invention has a certain alkalinity and can be used in ASP flooding to effectively reduce the oil-water interfacial tension.

[0103] Test Example 2

[0104] The organic alkaline surfactant in the embodiment and the comparative example was prepared into a 0.3 wt % solution with deionized water, and the solution and crude oil were mixed in a volume ratio of 1:1 to obtain a sample to be tested. The acid value of the liquid to be tested was measured with a PB-10 acidity meter at 25° C. The average value was taken after three consecutive measurements.

[0105] Table 2

[0106]

[0107]

[0108] It can be seen from the results in Table 2 that the organic alkaline surfactant provided by the present invention has a certain alkalinity and can react with crude oil to effectively reduce the acid value of crude oil.

[0109] Crude oil and petroleum ether were mixed in volume ratios of 1:0, 1:1, 1:2, 1:3, 1:4, 1:5, and 0:1 to obtain a mixed oil sample. The organic base surfactant of Example 1 was formulated into a 0.3wt% solution with deionized water, and the interfacial tension between the surfactant solution and the mixed oil sample was measured at 25°C using a TX-500C spinning drop interfacial tension meter.

[0110] Table 3

[0111] Oil Sample Crude oil: Petroleum ether pH Interfacial tension a 1:0 6.53 0.008 b 1:1 6.95 0.05 c 1:2 7.35 0.085 d 1:3 7.92 0.12 e 1:4 8.56 0.25 f 1:5 9.12 0.58 g 0:1 9.89 6.02

[0112] From the results in Table 3, it can be seen that the organic alkaline surfactant provided by the present invention has a certain alkalinity, can react with crude oil to reduce the acid value of crude oil to generate a substance with surface activity, and can effectively reduce the oil-water interfacial tension.

[0113] Test Example 3

[0114] 0.3 g of organic alkali surfactant and 0.1 g of partially hydrolyzed polyacrylamide (HPAM) were dissolved in 100 mL of deionized water to prepare a new binary composite oil displacement system. The oil displacement performance evaluation experiment of the new organic alkali binary composite oil displacement system was carried out using a multifunctional core displacement experimental device.

[0115] Experimental steps:

[0116] (1) The artificial core was weighed dry, the pore volume was measured, the core was saturated with oil by vacuum, and then aged at 60°C for 24 h.

[0117] (2) Set the flow rate to 0.5 mL / min, use simulated formation water as the displacement medium, and displace the artificial core until the water content of the produced fluid is greater than 98%; then use the new organic alkali binary composite oil displacement system to displace to 0.5 PV; continue water flooding, and stop the displacement when the water content of the produced fluid is greater than 98%. Record the changes in injection pressure and water content during the entire displacement process, and calculate the crude oil recovery factors at different displacement stages.

[0118] The specific test results are shown in Table 4.

[0119] Table 4

[0120] Improved oil recovery / % Example 1 22.52 Example 2 20.15 Example 3 18.92 Example 4 18.35 Example 5 16.85 Example 6 16.2 Example 7 15.6 Example 8 17.68

[0121] The present invention also provides an illustrative picture of the organic base surfactant prepared in Example 1,

[0122] The actual picture of the dissolution of organic alkaline surfactant in water, the infrared spectra of intermediates and organic alkaline surfactants, are respectively Figure 1 , Figure 2 , Figure 3 .

[0123] from Figure 3 It can be seen that the infrared spectra of the organic base intermediate and the organic base surfactant provided by the present invention are not much different. The main difference is that the 3442m -1 The absorption peak at 2923 cm is broader because the organic base surfactant has one more -OH than the intermediate. -1 、2854cm -1 、1460cm -1 The asymmetric and symmetric stretching vibration and bending vibration peaks of -CH2- are shown at 1660cm -1 The stretching vibration peak of secondary amine -NH- is at 1201cm -1 and 1049cm -1 They are the asymmetric and symmetric stretching vibration peaks of -S=O; 617cm -1 The peak is the asymmetric stretching vibration of -S=O.

[0124] In summary, embodiments 1-3 are preferred embodiments, and embodiment 1 is the best embodiment.

[0125] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A polyamine-based gemini anionic organic alkaline surfactant, characterized in that: The organic alkaline surfactant is a compound having a structure as shown in formula (I): Among them, n is 2, 3, and 4, respectively, and the corresponding raw materials are dibromoethane, 1,3-dibromopropane, and 1,4-dibromobutane.

2. The method for preparing a polyamine gemini anionic organic alkaline surfactant according to claim 1, characterized in that: The following steps are involved: (1) dissolving a first raw material in a solvent to obtain an alcohol solution containing the first raw material; wherein the first raw material is N-tallow triamine and the solvent is isopropanol; (2) dissolving the second raw material in a solvent to obtain an aqueous solution containing the second raw material; wherein the second raw material is sodium 3-chloro-2-hydroxypropanesulfonate and the solvent is deionized water; (3) contacting an alcohol solution containing the first raw material and an aqueous solution containing the second raw material in the presence of an alkaline catalyst to obtain a first mixed solution; (4) The first mixed solution is sequentially subjected to distillation treatment and drying treatment to obtain an intermediate. (5) dissolving the intermediate obtained in step (4) in a solvent to obtain an aqueous solution containing the intermediate; wherein the solvent is deionized water; (6) dissolving the third raw material in a solvent to obtain an alcohol solution containing the third raw material, wherein the third raw material is ethylene dibromide and the solvent is ethanol; (7) contacting the aqueous solution containing the intermediate and the alcohol solution containing the third raw material in the presence of a basic catalyst to obtain a second mixed solution; (8) The second mixed solution is sequentially subjected to distillation treatment and drying treatment to obtain a product.

3. The method for preparing a polyamine gemini anionic organic alkaline surfactant according to claim 2, characterized in that: In the step (1), the weight ratio of the first raw material to isopropanol is 1:5-6.

4. The method for preparing a polyamine gemini anionic organic alkaline surfactant according to claim 3, characterized in that: In the step (7), the molar ratio of the third raw material, the alkaline catalyst and the intermediate is 1-1.2:2:

2.

5. The method for preparing a polyamine gemini anionic organic alkaline surfactant according to claim 4, characterized in that: In the step (6), the weight ratio of the third raw material to the ethanol is 1:20-25.

6. The method for preparing a polyamine gemini anionic organic alkaline surfactant according to claim 5, characterized in that: In the step (3), the molar ratio of the second raw material, the alkaline catalyst and the first raw material is 3.7-4:1:3.33-3.

5.

7. The method for preparing a polyamine gemini anionic organic alkaline surfactant according to claim 6, characterized in that: In the step (2), the weight ratio of the second raw material to water is 1:3-4; in the step (5), the weight ratio of the intermediate to water is 1:3.5-4.

8. Use of the organic alkaline surfactant according to claim 1 in ASP flooding in oil fields.

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