Diester mono-tail cationic surfactants, methods of making and using the same

Abstract

The present application relates to the oil field chemical technical field, it is a kind of double ester single tail cationic surfactant and its preparation method and application, and a kind of acidification fracturing is used to help to discharge agent.The double ester single tail cationic surfactant is prepared from N,N-dimethyl-1,3 amine, methyl acrylate and halogenated alkane and other raw materials.The present application provides a kind of low-cost, green and environmentally friendly double ester single tail cationic surfactant, the preparation method of the double ester single tail cationic surfactant, simple operation, safe and reliable, conducive to industrial production and popularization and application, with broad market prospect.The acidification fracturing is used to help to discharge agent with the double ester single tail surfactant as raw material can effectively reduce the interfacial tension of aqueous solution, meet acidification fracturing technical specification.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil field chemistry, and is a kind of double ester single tail cationic surfactant and its preparation method and application, and a kind of acid fracturing cleanup aid. BACKGROUND

[0002] Acid fracturing reconstruction technology is an important measure for efficient development of oil and gas fields, and is a main technical means to realize unconventional oil and gas resource exploration and development, conventional oil and gas field yield increase and stable production, and improve reservoir reconstruction effect. In the process of acid fracturing, the well return fluid is usually quickly discharged to the ground by relying on the formation pressure. When the formation pressure gradually decreases, the return rate is significantly reduced, and the residue in the return fluid will cause plugging, resulting in secondary pollution of the formation, thereby seriously affecting the construction efficiency and acid fracturing reconstruction effect. In order to solve the problem of difficult return of return fluid after oil acid fracturing, using cleanup aid is a conventional means.

[0003] The cleanup aid is one of the fracturing fluid additives, which can effectively reduce the surface tension and interfacial tension, reduce the capillary resistance, and improve the return rate and return rate, thereby reducing the formation damage. Although there are many cleanup aid systems reported at home and abroad at present, most of them are prepared by using fluorocarbon surfactant and other surfactants. The fluorocarbon surfactant has high surface activity, and can reduce the surface tension to 23 mN / m. However, it is expensive, difficult to degrade, and has high biological toxicity. Therefore, it is urgent to develop a low-cost and green cleanup aid system. SUMMARY

[0004] The present application provides a kind of double ester single tail cationic surfactant, overcome the deficiency of above-mentioned prior art, it can effectively solve the problem of expensive, poor environmental protection of existing fracturing fluid surfactant.

[0005] One of the technical solutions of the present application is realized by the following measures: a kind of double ester single tail cationic surfactant, chemical structural formula is:

[0006]

[0007] Wherein, R is C 12 To C 16 Aliphatic hydrocarbon group, X is chlorine or bromine.

[0008] The following is a further optimization or / and improvement of the above-mentioned one of the technical solutions of the application:

[0009] The above-mentioned double ester single tail surfactant is prepared by the following steps:

[0010] The first step, in the reactor, N, N-dimethyl-1,3 amine is dissolved in anhydrous ethanol, stirring, reducing the reactor temperature to 0 to 5 DEG C, dropwise addition of methyl acrylate, after the dropwise addition is completed, continue to react at room temperature for 20h to 26h;

[0011] The second step, to the reactor, the addition of halogenated alkane, stirring, reflux reaction, after the reaction is completed, the reaction product is concentrated and the solvent is removed, then the reaction product is recrystallized with ethyl acetate, and a viscous liquid diester single tail cationic surfactant is obtained.

[0012] In the above first step, the molar ratio of methyl acrylate to N, N-dimethyl-1,3 amine is 2.0 to 2.2.

[0013] In the above first step, the halogenated alkane is a brominated alkane or a chlorinated alkane.

[0014] In the above second step, the molar ratio of halogenated alkane to N, N-dimethyl-1,3 amine is 1.0 to 1.1.

[0015] In the above second step, the reaction temperature of the reflux reaction is 70 DEG C to 90 DEG C, and the reaction time is 10h to 14h.

[0016] The second technical solution of the present application is realized by the following measures: a preparation method of a diester single tail cationic surfactant, which is carried out according to the following steps: the first step, in the reactor, N, N-dimethyl-1,3 amine is dissolved in anhydrous ethanol, stirring, reducing the reactor temperature to 0 to 5 DEG C, dropwise addition of methyl acrylate, after the dropwise addition is completed, continue to react at room temperature for 20h to 26h;

[0017] The second step, to the reactor, the addition of halogenated alkane, stirring, reflux reaction, after the reaction is completed, the reaction product is concentrated and the solvent is removed, then the reaction product is recrystallized with ethyl acetate, and a viscous liquid diester single tail cationic surfactant is obtained.

[0018] The third technical solution of the present application is realized by the following measures: an application of a diester single tail surfactant in a fracturing fluid additive.

[0019] The fourth technical solution of the present application is realized by the following measures: an acidizing fracturing cleanup aid, the composition of the raw material is as follows: 8 to 9.5 parts of anionic surfactant, 0.5 to 2 parts of diester single tail surfactant, 0 to 1 part of sugar-based surfactant, and the rest is water; the required amount of anionic surfactant, diester single tail surfactant, sugar-based surfactant and water are stirred and mixed uniformly at room temperature to obtain the acidizing fracturing cleanup aid.

[0020] The following is a further optimization or / and improvement of the fourth technical solution of the above invention:

[0021] The anionic surfactant is sodium fatty alcohol polyoxyethylene ether carboxylate, and its chemical structural formula is as follows:

[0022]

[0023] wherein, R1 is a fatty alkyl group of C 12 to C 18 , and n is an integer greater than or equal to 2.

[0024] The sugar-based surfactant is N-alkyl glucosamine, and its chemical structural formula is as follows:

[0025]

[0026] wherein, R2 is a fatty alkyl group of C 12 to C 16 .

[0027] The present application provides a low-cost, green and environmentally friendly diester single-tailed cationic surfactant, a preparation method thereof, which is simple to operate, safe and reliable, and is conducive to industrialized production and popularization and application, and has a broad market prospect. The cleanup aid for acidizing and fracturing using the diester single-tailed surfactant as a raw material can effectively reduce the interfacial tension of an aqueous solution, and meet the technical specifications of the cleanup aid for acidizing and fracturing. DETAILED DESCRIPTION

[0028] The present application is not limited by the following examples, and the specific implementation can be determined according to the technical solutions of the present application and the actual situation. In the present application, various chemical reagents and chemical products mentioned are well-known and commonly used chemical reagents and chemical products in the prior art unless otherwise specified; the percentages in the present application are mass percentages unless otherwise specified; the solutions in the present application are aqueous solutions with water as the solvent unless otherwise specified, for example, a hydrochloric acid solution is an aqueous hydrochloric acid solution; the normal temperature and room temperature in the present application generally refer to a temperature of 15-25℃, and are generally defined as 25℃.

[0029] The present application will be further described below in conjunction with examples:

[0030] Example 1: The diester single-tailed surfactant has a chemical structural formula as follows:

[0031]

[0032] wherein, R is a fatty alkyl group of C 12 to C 16 , and X is chlorine or bromine.

[0033] Example 2: As an optimization of the above example, the diester single-tailed surfactant is prepared by the following steps:

[0034] First step, N,N-dimethyl-1,3 amine is dissolved in anhydrous ethanol in a reactor, stirred evenly, the temperature of the reactor is reduced to 0-5℃, and methyl acrylate is added dropwise. After the dropwise addition is completed, the reaction is continued at room temperature for 20-26 hours;

[0035] Second step, halogenated alkane is added to the reactor, stirred evenly, and the reaction is carried out under reflux. After the reaction is completed, the reaction product is concentrated and the solvent is removed. Then the reaction product is recrystallized with ethyl acetate to obtain a viscous liquid of the diester single-tail cationic surfactant.

[0036] In the present application, the temperature of the reactor can be reduced to 0-5℃ by using a low-temperature water bath. The concentration and solvent removal of the reaction product can be carried out by rotary evaporation.

[0037] The chemical reaction process of the above preparation method is as follows:

[0038] (1) In the first step, the preparation of the diester intermediate:

[0039]

[0040] (2) In the second step, the preparation of the product diester single-tail cationic surfactant:

[0041]

[0042] Example 3: As an optimization of the above examples, in the first step, the molar ratio of methyl acrylate to N,N-dimethyl-1,3 amine is 2.0-2.2.

[0043] Example 4: As an optimization of the above examples, in the first step, the halogenated alkane is brominated alkane or chlorinated alkane.

[0044] Example 5: As an optimization of the above examples, in the second step, the molar ratio of halogenated alkane to N,N-dimethyl-1,3 amine is 1.0-1.1.

[0045] Example 6: As an optimization of the above examples, in the second step, the reaction temperature of the reflux reaction is 70-90℃, and the reaction time is 10-14 hours.

[0046] Example 7: Application of the diester single-tail surfactant in fracturing fluid additives.

[0047] Example 8: The cleanup aid for acid fracturing, the composition of each 100 parts of raw materials is as follows: anionic surfactant 8-9.5 parts, diester single-tail surfactant 0.5-2 parts, sugar-based surfactant 0-1 part, and the rest is water; the required amount of anionic surfactant, diester single-tail surfactant, sugar-based surfactant and water are stirred and mixed evenly at room temperature to obtain the cleanup aid for acid fracturing.

[0048] The cleanup aid for acid fracturing of the present application can be directly prepared on site with oilfield produced water, flowback fluid and other oilfield sewage, which is convenient for acid fracturing operation.

[0049] Example 9: As an optimization of the above examples, the anionic surfactant is a sodium fatty alcohol polyoxyethylene ether carboxylate, and its chemical structural formula is:

[0050]

[0051] wherein R1 is a C12 to C18 aliphatic group, and n is an integer greater than or equal to 2.

[0052] Example 10: As an optimization of the above examples, the sugar-based surfactant is N-alkyl glucosamine, and its chemical structural formula is:

[0053]

[0054] wherein R2 is a C12 to C16 aliphatic group.

[0055] Example 11:

[0056] Preparation of a double ester single tail cationic surfactant:

[0057] 0.1 mol of N,N-dimethyl-1,3-amine was dissolved in 100 mL of anhydrous ethanol, stirred uniformly, and the temperature was reduced to below 5℃ in an ice water bath. 0.2 mol of methyl acrylate was slowly added dropwise, and after the addition was completed, the reaction was continued for 24 h. 0.1 mol of bromohexadecane was added and stirred uniformly, and the temperature was raised to 80℃. The reaction was refluxed for 8 h. The solvent was recovered by rotary evaporation, and the reaction product was recrystallized with ethyl acetate to obtain a viscous liquid double ester single tail cationic surfactant DMST-16 with a yield of 89.6%.

[0058] Preparation of a cleanup aid for acid fracturing:

[0059] 9.0 parts of sodium lauryl polyoxyethylene ether (3) carboxylate, 1.0 part of DMST-16 and 90 parts of water were weighed, stirred at room temperature, and dissolved uniformly to prepare 100 parts of a cleanup aid for acid fracturing.

[0060] The results of indoor experimental tests on the acid fracturing pumping aid showed that the surface tension of the 0.3% sodium lauryl ether (3) carboxylate aqueous solution was 22.648 mN / m and the interfacial tension was 4.051 mN / m, which did not meet the industry standards for non-fluorocarbon pumping aids. The surface tension of the 0.3% acid fracturing pumping aid was 23.738 mN / m and the interfacial tension was 0.214 mN / m, which met the industry standards for non-fluorocarbon pumping aids. This indicates that the combination of the diester single-tailed cationic surfactant DMST-16 and the anionic surfactant sodium lauryl ether (3) carboxylate of the present invention can significantly reduce the interfacial tension, while greatly reducing the amount of surfactant used and lowering the cost of use.

[0061] Example 12:

[0062] Preparation of diester-based single-tailed cationic surfactants:

[0063] 0.1 mol of N,N-dimethyl-1,3-propanediamine was dissolved in 100 mL of anhydrous ethanol and stirred until homogeneous. The temperature was lowered to below 5 °C in an ice-water bath, and 0.22 mol of methyl acrylate was slowly added dropwise. After the addition was complete, the reaction continued for 24 h. 0.11 mol of hexadecane bromide was added, stirred until homogeneous, and the temperature was raised to 80 °C. The reaction was refluxed for 12 h, and the solvent was recovered by rotary evaporation. The reaction product was recrystallized from ethyl acetate to obtain a viscous liquid diester mono-tailed cationic surfactant, DMST-16, with a yield of 94.7%.

[0064] Preparation of flow-out aids for acid fracturing:

[0065] Weigh 9.0 parts of sodium lauryl alcohol polyoxyethylene ether (3) carboxylate, 0.5 parts of DMST-16, 0.5 parts of N-dodecyl glucosamine and 90 parts of water, stir at room temperature and dissolve evenly to prepare 100 parts of acid fracturing aid.

[0066] Indoor experimental tests on this acid fracturing flow aid showed that the surface tension of the 0.3% acid fracturing flow aid was 24.784 mN / m and the interfacial tension was 0.089 mN / m, which meets the industry standards for non-fluorocarbon flow aids. The use of sugar-based surfactants further significantly reduced the interfacial tension, indicating that it has a good synergistic effect.

[0067] Example 13:

[0068] Preparation of diester-based single-tailed cationic surfactants:

[0069] The 0.1 mol of N, N-dimethyl-1, 3-propanediamine is dissolved in 100 mL of anhydrous ethanol, stirred uniformly, the temperature is reduced to below 5°C by ice water bath, 0.22 mol of methyl acrylate is slowly added dropwise, after the addition is completed, the reaction is continued for 24 h; 0.11 mol of bromohexadecane is added, stirred uniformly, the temperature is increased to 80°C, the reflux reaction is carried out for 24 h, the solvent is recovered by rotary evaporation, the reaction product is recrystallized with ethyl acetate, and the double-ester single-tail cationic surfactant DMST-16 in a viscous liquid is obtained, and the yield is 95.4%.

[0070] Preparation of the cleanup agent for acid fracturing:

[0071] 9.0 parts of sodium lauryl polyoxyethylene ether (3) carboxylate, 1.0 part of double DMST-16, 0.5 part of N-dodecyl glucosamine and 89.5 parts of water are weighed, stirred at room temperature, and uniformly dissolved to prepare 100 parts of the cleanup agent for acid fracturing.

[0072] The indoor experimental test results of the cleanup agent for acid fracturing show that the surface tension of 0.3% of the cleanup agent for acid fracturing is 23.123 mN / m, and the interfacial tension is 0.038 mN / m, meeting the non-fluorocarbon cleanup agent industry use standard, and the use of sugar-based surfactants further significantly reduces the interfacial tension, indicating that it has good composite synergistic effect.

[0073] Example 14:

[0074] Preparation of double-ester single-tail cationic surfactant:

[0075] The 0.1 mol of N, N-dimethyl-1, 3-propanediamine is dissolved in 100 mL of anhydrous ethanol, stirred uniformly, the temperature is reduced to below 5°C by ice water bath, 0.22 mol of methyl acrylate is slowly added dropwise, after the addition is completed, the reaction is continued for 24 h; 0.11 mol of bromohexadecane is added, stirred uniformly, the temperature is increased to 80°C, the reflux reaction is carried out for 24 h, the solvent is recovered by rotary evaporation, the reaction product is recrystallized with ethyl acetate, and the double-ester single-tail cationic surfactant DMST-16 in a viscous liquid is obtained, and the yield is 95.4%.

[0076] Preparation of the cleanup agent for acid fracturing:

[0077] 8.5 parts of sodium lauryl polyoxyethylene ether (3) carboxylate, 1.5 parts of DMST-12, 0.5 part of N-tetradecyl glucosamine and 89.5 parts of water are weighed, stirred at room temperature, and uniformly dissolved to prepare 100 parts of the cleanup agent for acid fracturing.

[0078] The indoor experimental test results of the acid fracturing cleanup additive show that the surface tension of 0.3% acid fracturing cleanup additive is 23.281 mN / m, the interfacial tension is 0.085 mN / m, which meets the non-fluorocarbon cleanup additive industry use standard, the use of sugar-based surfactant further significantly reduces the interfacial tension, which shows good composite synergistic effect.

[0079] Example 15:

[0080] Preparation of double ester single tail cationic surfactant:

[0081] 0.1 mol of N,N-dimethyl-1,3 propanediamine is dissolved in 100 mL of anhydrous ethanol, stirred uniformly, the temperature is reduced to below 5 DEG C by ice water bath, 0.22 mol of methyl acrylate is slowly added dropwise, after the dropwise addition is completed, the reaction is continued for 24 h; 0.11 mol of bromotetradecane is added, stirred uniformly, the temperature is increased to 80 DEG C, refluxed for 12 h, the solvent is recovered by rotary evaporation, the reaction product is recrystallized with ethyl acetate, double ester single tail cationic surfactant DMST-14 in viscous liquid is obtained, the yield is 94.5%.

[0082] Preparation of acid fracturing cleanup additive:

[0083] 8.5 parts of sodium lauryl polyoxyethylene ether (3) carboxylate, 1.5 parts of DMST-14, 0.5 parts of N-hexadecyl glucosamine and 89.5 parts of water are weighed, stirred at room temperature, and uniformly dissolved to prepare 100 parts of acid fracturing cleanup additive.

[0084] The indoor experimental test results of the acid fracturing cleanup additive show that the surface tension of 0.3% acid fracturing cleanup additive is 22.605 mN / m, the interfacial tension is 0.002 mN / m, which meets the non-fluorocarbon cleanup additive industry use standard, the use of sugar-based surfactant further significantly reduces the interfacial tension, which shows good composite synergistic effect.

[0085] The double ester single tail cationic surfactant of the application is prepared by "one-pot method", the method is simple, the product yield is high, it is safe and reliable, the cost is effectively reduced, the production cycle is shortened, it has good composite synergistic characteristics with commonly used anionic surfactants, nonionic surfactants and the like, can effectively reduce the surface interfacial tension, and significantly reduce the amount of surfactant, and reduce the use cost.

[0086] The above technical features constitute the embodiments of the application, have strong adaptability and implementation effect, unnecessary technical features can be added or reduced according to actual needs to meet the needs of different situations.

Claims

1. A diester mono-tail cationic surfactant characterized in that The chemical structural formula is: wherein R is C 12 to C 16 aliphatic hydrocarbon group, and X is chlorine or bromine.

2. A process for the preparation of a diester mono-tail cationic surfactant according to claim 1, characterized by The following steps are taken to prepare: In the first step, N, N-dimethyl-1, 3 amine is dissolved in anhydrous ethanol in a reactor, stirred uniformly, the temperature of the reactor is reduced to 0-5℃, and methyl acrylate is added dropwise. After the dropwise addition is completed, the reaction is continued at room temperature for 20-26 hours. In the second step, halogenated alkane is added to the reactor, stirred uniformly, and refluxed. After the reaction is completed, the reaction product is concentrated and the solvent is removed. Then, the reaction product is recrystallized with ethyl acetate to obtain a viscous liquid of the double ester single tail cationic surfactant.

3. The method of making a double ester mono-tail cationic surfactant according to claim 2, wherein In the first step, the molar ratio of methyl acrylate to N, N-dimethyl-1, 3 amine is 2.0-2.

2.

4. The method of making a double ester mono-tail cationic surfactant according to claim 2 or 3, characterized in that In the first step, the halogenated alkane is a brominated alkane or a chlorinated alkane.

5. The method of making a double ester mono-tail cationic surfactant according to claim 2 or 3, characterized in that In the second step, the molar ratio of halogenated alkane to N, N-dimethyl-1, 3 amine is 1.0-1.1; or / and, in the second step, the reaction temperature of the reflux reaction is 70-90℃, and the reaction time is 10-14 hours.

6. The use of the double ester single tail cationic surfactant according to claim 1 as a fracturing fluid additive.

7. A cleanup additive for acidizing fracturing using the double ester mono-tail cationic surfactant of claim 1 as raw material, characterized in that The composition of the raw materials is as follows: 8-9.5 parts of anionic surfactant, 0.5-2 parts of double ester single tail surfactant, 0-1 part of sugar-based surfactant, and the rest is water. The required amount of anionic surfactant, double ester single tail surfactant, sugar-based surfactant, and water are stirred and mixed uniformly at room temperature to obtain the cleanup additive for acidizing fracturing.

8. The cleanup aid for acidizing fracturing of claim 7, characterized in that The anionic surfactant is sodium fatty alcohol polyoxyethylene ether carboxylate, and its chemical structural formula is: wherein R1is a C 12 to C 18 aliphatic hydrocarbon group, and n is an integer greater than or equal to 2.

9. The cleanup aid for acidizing fracturing of claim 7 or 8, characterized in that The sugar-based surfactant is N-alkyl glucosamine, and its chemical structural formula is: wherein R2is C 12 to C 16 aliphatic hydrocarbon groups.

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