Cationic surfactant and its preparation and application
By preparing a cationic surfactant with dehydroabietic acid as the substrate and sodium octanoate to form a viscoelastic solution, the low retention rate and high cost of polymer oil repellent in the mining of high temperature and low permeability reservoirs is solved, and a low-cost and efficient oil repellent effect is achieved.
Patent Information
- Application Number
- CN202210718341.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-06-23
- Publication Date
- 2025-08-22
- Estimated Expiration
- 2042-06-23
AI Technical Summary
In the mining of unconventional high-temperature and low permeability reservoirs, existing polymer oil repellents have problems such as low retention rate, filtration loss of substances to damage the formation, and high cost, and viscoelastic surfactants are costly to use at high concentrations.
Dehydroabietic acid is used as the substrate to prepare cationic surfactants. By reacting with sulfoxide chloride, methyl aminoundecanoate hydrochloride, 3-dimethylaminopropylamine and bromoethane, a cationic surfactant with a rigid skeleton of tricyclic diterpene is formed, and combined with sodium octanoate to form a viscoelastic solution.
It exhibits high viscoelasticity at low concentrations, reduces mining costs, improves oil displacement efficiency, is environmentally friendly and is easy to obtain.
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Figure CN117326971B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a cationic surfactant and its preparation and application. Background Art
[0002] Petroleum is a vital fuel in industrial society, offering advantages unmatched by other fuels and earning it the nickname "the lifeblood of industry." However, with the continued development of conventional oil and gas reservoirs, unconventional high-temperature, low-permeability reservoirs are in urgent need of development and utilization, and conventional extraction methods are no longer sufficient. For such oilfields, viscoelastic surfactants are the most commonly used method to improve reservoir permeability. During the displacement process, the performance of the oil-displacing agent used directly impacts the success of the technology and the subsequent production increase.
[0003] The earliest water-based oil-displacement agents were primarily composed of high-molecular-weight substances such as natural plant gums and synthetic polymers. While these agents demonstrated promising yield-increasing effects, they also possessed significant drawbacks. For example, the flowback rate of these agents was only 30% to 45%, with most of the residue remaining underground. This retained material contained significant amounts of water-insoluble matter, which could significantly damage the proppant and reduce formation permeability, severely impacting oil and gas production. In the mid-to-late 1990s, Schlumberger developed a novel surfactant-based oil-displacement system, viscoelastic surfactant (VES) oil-displacement agents. VES oil-displacement agents offer a range of advantages, including strong sand-carrying capacity, low fluid loss, the absence of solid residues, minimal damage to proppant permeability, automatic gel breaking upon contact with oil or hydrocarbon gas, and a high flowback rate. However, compared to high-molecular-weight oil-displacement agents such as guar gum, VES oil-displacement agents often require higher concentrations to achieve the required viscosity, increasing oil recovery costs.
[0004] In oil-displacing agents formed by surfactants, the molecular structure and intermolecular interactions of the surfactants are closely related to the performance of the oil-displacing agents. Rosin has the advantages of being renewable and biodegradable. The tricyclic diterpenes in its main component, dehydroabietic acid, have a large molecular skeleton and strong van der Waals interactions with each other, which can effectively promote the aggregation of surfactants. For details, please refer to: Chemistry and Industry of Forest Products, 2015, 35(06), 39-46; Journal of Forestry Engineering, 2019, 4(06), 83-90. Summary of the Invention
[0005] In order to at least partially solve the problems in the prior art, the present invention provides the following technical solutions:
[0006] In a first aspect, the present invention provides a cationic surfactant having the following molecular structure:
[0007] .
[0008] In a second aspect, the present invention provides a method for preparing the above-mentioned cationic surfactant, comprising:
[0009] (1) Dehydroabietic acid reacts with thionyl chloride under the catalysis of 4-dimethylaminopyridine to obtain dehydroabietic acid chloride;
[0010] (2) Dehydroabietoyl chloride reacts with aminoundecanoic acid methyl ester hydrochloride to obtain compound 1;
[0011] (3) Compound 1 reacts with 3-dimethylaminopropylamine to obtain compound 2;
[0012] (4) Compound 2 reacts with ethyl bromide to obtain the cationic surfactant.
[0013] In one or some optional embodiments, the method includes:
[0014] The step (1) comprises: adding 4-dimethylaminopyridine as a catalyst to dehydroabietic acid, and adding thionyl chloride at 35°C to obtain dehydroabietic acid chloride;
[0015] The step (2) comprises reacting aminoundecanoic acid methyl ester hydrochloride and dehydroabietoyl chloride in a dichloromethane system to obtain compound 1;
[0016] The step (3) is as follows: compound 1 and 3-dimethylaminopropylamine react under KOH catalysis conditions to obtain compound 2.
[0017] In one or some optional embodiments, the method is as follows:
[0018] Add dehydroabietic acid solid to a three-necked flask, then add a catalytic amount of 4-dimethylaminopyridine. When the temperature rises to 35°C, slowly add thionyl chloride dropwise. The generated gas is absorbed with alkaline solution. After the thionyl chloride is added dropwise, react at 35°C for 3 hours. After the reaction is completed, remove excess thionyl chloride from the cooled reaction product by vacuum distillation to obtain dehydroabietoyl chloride.
[0019] A dichloromethane solution of aminoundecanoic acid methyl ester hydrochloride was added to a three-necked flask, and a dichloromethane solution of dehydroabietyl chloride was slowly added dropwise at 0°C. After the addition was complete, the mixture was reacted at room temperature for 3 hours. After the reaction was complete, water was added to the mixture, and then extracted with dichloromethane. The extracted organic layer was washed 5-6 times with alkaline water with a pH of 12, and then the organic layer was dried over anhydrous sodium sulfate. After suction filtration, the solvent was distilled off under reduced pressure, and purified by column chromatography to obtain compound 1;
[0020] Compound 1 and 3-dimethylaminopropylamine were placed in a three-necked flask, a trace amount of KOH solid was added as a catalyst, and the mixture was stirred magnetically at 90°C for 36 hours. After the reaction was completed, the excess 3-dimethylaminopropylamine was removed by vacuum distillation, and then purified by column chromatography to obtain compound 2.
[0021] The ethanol solution of compound 2 and bromoethane was placed in a single-necked bottle and magnetically stirred at 90° C. under reflux conditions for 36 hours. After the reaction was completed, the solvent was removed by vacuum distillation, and the sample was purified by recrystallization using ethanol / ethyl acetate to obtain the cationic surfactant.
[0022] In a third aspect, the present invention further provides a use of the above-mentioned cationic surfactant in preparing a viscoelastic solution.
[0023] In a fourth aspect, the present invention provides a viscoelastic solution, which is prepared by compounding a cationic surfactant and sodium octanoate.
[0024] In one or some optional embodiments, the molar ratio of the cationic surfactant to sodium caprylate is in the range of 1:0.5 to 1:5.
[0025] In a fifth aspect, the present invention provides a method for preparing the above-mentioned viscoelastic solution, comprising: mixing the above-mentioned cationic surfactant with sodium octanoate.
[0026] In a sixth aspect, the present invention proposes an application of the above-mentioned viscoelastic solution in oil production.
[0027] In a seventh aspect, the present invention proposes an application of the viscoelastic solution in toiletries.
[0028] Based on the above technical solution, the present invention has the following beneficial effects compared with the prior art:
[0029] Cationic surfactants are prepared using dehydroabietic acid as a substrate. Dehydroabietic acid has a rigid tricyclic diterpene skeleton, and the cationic surfactants prepared using it also have a rigid tricyclic diterpene skeleton. This gives the cationic surfactants strong intermolecular forces, resulting in excellent aggregation ability, high viscoelasticity at low concentrations, and low application cost. Furthermore, dehydroabietic acid is the main component of rosin, which is renewable, biodegradable, inexpensive, and abundant. Cationic surfactants prepared using dehydroabietic acid are environmentally friendly, and the raw materials required for their preparation are readily available. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 is the H NMR spectrum of a cationic surfactant;
[0031] Figure 2Here are photos of the appearance of cationic surfactant / sodium octanoate solutions at different ratios;
[0032] Figure 3 These are the steady-state rheological data for solutions with cationic surfactant / sodium octanoate ratios of 1:0.5, 1:0.8, and 1:1;
[0033] Figure 4 Here are photos of the appearance of cationic surfactant / sodium octanoate solutions at different concentrations;
[0034] Figure 5 is the steady-state shear diagram of cationic surfactant / sodium octanoate solution with different concentrations;
[0035] Figure 6 It is the dynamic shear diagram of cationic surfactant / sodium octanoate solution with different concentrations;
[0036] Figure 7 This is a comparison chart of the steady-state rheology of cationic surfactant / sodium octanoate solution and octadecyltrimethylammonium chloride / sodium salicylate solution. DETAILED DESCRIPTION
[0037] The following is a detailed description of the embodiments of the present invention: This embodiment is implemented based on the technical solution of the present invention, and a detailed implementation method and process are given. However, the scope of protection of the present invention is not limited to the following embodiments. The process parameters for which specific conditions are not specified in the following embodiments are generally based on conventional conditions.
[0038] The endpoints of the ranges and any values disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values can be combined with each other to form one or more new numerical ranges, and these numerical ranges should be considered to be specifically disclosed in the present invention.
[0039] The following is a detailed description of a cationic surfactant provided by the embodiments of the present invention and various specific embodiments of its preparation and application.
[0040] Example 1
[0041] Example 1 is the preparation of a cationic surfactant.
[0042] Dehydroabietic acid solid (20 g, 0.067 mol) was added to a three-necked flask 1 equipped with a reflux condenser, and a catalytic amount of 4-dimethylaminopyridine was added as a catalyst. When the temperature rose to 35 °C, thionyl chloride (11.96 g, 0.10 mol) was slowly added dropwise to the three-necked flask 1. During the addition of thionyl chloride, a large amount of gas was generated, which was absorbed with alkaline solution to prevent it from polluting the atmospheric environment. After the addition of thionyl chloride was completed, the reaction was carried out at 35 °C for 3 h. After the reaction was completed, the cooled reaction product was distilled under reduced pressure to remove excess thionyl chloride to obtain dehydroabietoyl chloride.
[0043] A dichloromethane solution of methyl aminoundecanoate hydrochloride (20 g, 0.08 mol) was added to a three-necked flask 2 with a reflux condenser, and a dichloromethane solution of triethylamine (24.3 g, 0.24 mol) was added to neutralize the hydrogen chloride generated during the reaction. A dichloromethane solution of dehydroabietyl chloride was slowly added dropwise to the three-necked flask 2 at 0°C, and the reaction was carried out at room temperature for 3 h. After the reaction was completed, water was added to the mixture, and the mixture was extracted with dichloromethane to obtain an organic layer; the obtained organic layer was washed 5-6 times with alkaline water with a pH = 12, and then the organic layer was dried over anhydrous sodium sulfate. After filtration, the solvent was distilled off under reduced pressure, and the product after the above treatment was purified by column chromatography to obtain compound 1.
[0044] Compound 1 (30 g, 0.06 mol) and 3-dimethylaminopropylamine (18.5 g, 0.18 mol) were added to a three-necked flask 3 with a reflux condenser, and a trace amount of KOH solid was added as a catalyst. The mixture was magnetically stirred at 90°C under reflux conditions for 36 hours. After the reaction was completed, the excess 3-dimethylaminopropylamine was removed by vacuum distillation, and the product after the above treatment was purified by column chromatography to obtain compound 2.
[0045] A solution of compound 2 (25 g, 0.53 mol) and bromoethane (28.7 g, 0.26 mol) in ethanol / acetone was placed in a single-necked flask with a reflux condenser and magnetically stirred at 90°C for 36 hours. After the reaction, the solvent was removed by distillation under reduced pressure, and the product after the above treatment was recrystallized using ethanol / ethyl acetate for purification to obtain a cationic surfactant.
[0046] Weigh 10 mg of the cationic surfactant prepared above and place it in an NMR tube. Dissolve it with the deuterated reagent CDCl3. 1H NMR analysis was performed using an Aduance III NMR spectrometer at 25 °C. The test results are shown in Figure 2. Figure 1 As shown. Figure 1 It can be seen from the hydrogen nuclear magnetic resonance spectrum of the cationic surfactant that there are no impurity peaks on the spectrum, indicating that the product has reached a very high purity.
[0047] Example 2
[0048] Example 2 is an oil-displacing agent formed by compounding cationic surfactants and sodium octanoate in different proportions.
[0049] A certain amount of cationic surfactant solution with a concentration of 0.675 wt% was prepared and divided into 5 parts. Sodium octanoate solid was added at a molar mass ratio of 1:0.5, 1:0.8, 1:1, 1:1.2, and 1:1.5 to the cationic surfactant, respectively. The solution was heated to 70 °C to accelerate the dissolution and ensure that the system was uniform. The solution was then placed in a constant temperature box at 25 °C for 48 h. The solution state was observed and the steady-state rheological data of the clarified solution was tested. Figure 2 and Figure 3 shown.
[0050] like Figure 2 As shown in the figure, as the amount of sodium octanoate added increases, the solution state changes from a low-viscosity fluid to a transparent gel and then to an opaque gel. The addition of excessive counterion sodium carboxylate salts leads to the precipitation of surfactants. Among them, when the sodium octanoate and cationic surfactant are equal or less, the solution is clear and transparent. The rheological data of the solutions with a cationic surfactant and sodium octanoate ratio of 1:0.5, 1:0.8 and 1:1 are shown in the figure. Figure 3 As shown, the solution undergoes a transition from a Newtonian fluid to a non-Newtonian fluid, and the solution viscosity increases with increasing sodium octanoate concentration. When the ratio of the two is less than 1:1, the solution has poor viscoelasticity, while when the ratio is greater than 1:1, the surfactant in the solution tends to precipitate. Therefore, when the ratio of cationic surfactant to sodium octanoate is 1:1, the resulting oil displacement agent has the best viscoelasticity.
[0051] Example 3
[0052] Example 3 is an oil-displacing agent with different concentrations formed by compounding a cationic surfactant and sodium octanoate.
[0053] Take 3 mL of deionized water and add a cationic surfactant and sodium octanoate in a ratio of 1:1. The concentrations are 0.063 wt%, 0.12 wt%, 0.25 wt%, 0.38 wt%, 0.63 wt%, 1.26 wt%, and 1.68 wt%, respectively. Heat the solution to 50 °C and stir it evenly with a magnetic stirrer to ensure that the solution is completely dissolved and mixed evenly. Let it stand at 25 °C for 36 h and observe the state of the solution.
[0054] Figure 4Photos of the appearance of cationic surfactant / sodium octanoate at different concentrations are shown. It can be observed that at a concentration of only 0.38 wt%, the solution can support its own gravity and remains inverted, demonstrating the system's highly effective viscoelastic properties. At concentrations above 1.26 wt%, the solution exhibits a translucent gel-like state with some solid precipitation. Therefore, the optimal concentration range for achieving viscoelastic properties is between 0.06 wt% and 1.26 wt%.
[0055] Example 4
[0056] Example 4 is a measurement of the viscoelasticity of the oil-displacing agent formed by compounding different concentrations of cationic surfactant and sodium octanoate in Example 3.
[0057] Before dynamic scanning, stress scanning is performed to determine the linear viscoelastic region of the test sample. All sample tests are performed within the linear viscoelastic region. Figure 5 From the steady-state shear diagrams of cationic surfactant / sodium octanoate solutions with different concentrations, it can be seen that when the concentration is 0.06 wt%, the solution exhibits Newtonian fluid behavior, that is, the viscosity does not change with the change of shear rate, and its viscosity is not much different from the viscosity of water. As the concentration of the solution increases, the solution exhibits non-Newtonian fluid behavior. At low shear rates, the viscosity of each sample remains almost unchanged, and its corresponding viscosity is called zero shear viscosity, which is an important parameter for measuring the viscoelasticity of the solution. Figure 5 It can be seen that when the solution concentration is only 0.25 wt%, the zero-shear viscosity of the solution reaches 15,000 mPa·s, demonstrating the system's efficient viscoelastic properties. However, as the shear rate increases, the solution viscosity decreases, a phenomenon known as shear thinning, which is due to the breakdown of the aggregate structure at high shear rates. Figure 6 Dynamic shear diagrams of cationic surfactant / sodium octanoate solutions with different concentrations are shown (where: G΄ is the storage modulus, solid symbols; G″ is the loss modulus, hollow symbols). The behavior of the cationic surfactant / sodium octanoate solutions all exhibit similar patterns. Over the entire shear frequency range, the storage modulus is always greater than the loss modulus, indicating that the system exhibits solid-like characteristics.
[0058] Comparative Example 1:
[0059] Comparative Example 1 is a comparative example of Example 3.
[0060] To 3 ml of deionized water, equimolar amounts of octadecyltrimethylammonium chloride and sodium salicylate (concentrations of 0.25 wt % and 0.38 wt %) were added. The solution was heated to 50°C and stirred evenly with a magnetic stirrer to ensure complete dissolution and uniform mixing. The solution was allowed to stand at 25°C for 24 h. The viscoelastic properties of the solution were tested using the method of Example 4.
[0061] Figure 7 Steady-state rheological plots for equal concentrations of a cationic surfactant / sodium octanoate solution and octadecyltrimethylammonium chloride / sodium salicylate are shown. The plot shows that when the total concentration of the octadecyltrimethylammonium chloride / sodium salicylate solution is 0.25 wt%, the zero-shear viscosity is approximately 1600 mPa·s, while the zero-shear viscosity of the cationic surfactant / sodium octanoate system is over 10 times higher.
[0062] The above are only preferred embodiments of the present invention, and do not limit the protection scope of the present invention. Various modifications or applications made according to the above embodiments are within the protection scope of this technical solution.
[0063] Although specific embodiments of the present invention have been described in detail, it will be understood by those skilled in the art that various modifications and substitutions may be made to those details in light of all the teachings disclosed herein, and such modifications are within the scope of the present invention. The full scope of the present invention is given by the appended claims and any equivalents thereof.
Claims
1. A cationic surfactant, characterized in that The cationic surfactant has the following molecular structure:
2. A method for preparing the cationic surfactant according to claim 1, characterized in that: include: (1) Dehydroabietic acid reacts with thionyl chloride under the catalysis of 4-dimethylaminopyridine to obtain dehydroabietic acid chloride; (2) reacting dehydroabietoyl chloride with aminoundecanoic acid methyl ester hydrochloride to obtain compound 1; (3) Compound 1 reacts with 3-dimethylaminopropylamine to obtain compound 2; (4) Compound 2 reacts with ethyl bromide to obtain the cationic surfactant.
3. The method according to claim 2, wherein include: The step (1) comprises: adding 4-dimethylaminopyridine as a catalyst to dehydroabietic acid, and adding thionyl chloride at 35° C. to obtain dehydroabietic acid chloride; The step (2) comprises reacting aminoundecanoic acid methyl ester hydrochloride and dehydroabietoyl chloride in a dichloromethane system to obtain compound 1; The step (3) is as follows: compound 1 and 3-dimethylaminopropylamine react under KOH catalysis conditions to obtain compound 2.
4. The method according to claim 3, wherein The method is as follows: Add dehydroabietic acid solid to a three-necked flask, then add a catalytic amount of 4-dimethylaminopyridine. When the temperature rises to 35°C, slowly add thionyl chloride dropwise. The generated gas is absorbed with alkaline solution. After the addition of thionyl chloride is completed, react at 35°C for 3 hours. After the reaction is completed, remove excess thionyl chloride from the cooled reaction product by vacuum distillation to obtain dehydroabietoyl chloride. A dichloromethane solution of aminoundecanoic acid methyl ester hydrochloride was added to a three-necked flask, and a dichloromethane solution of dehydroabietyl chloride was slowly added dropwise at 0°C. After the addition was complete, the mixture was reacted at room temperature for 3 hours. After the reaction was complete, water was added to the mixture, and then extracted with dichloromethane. The organic layer after extraction was washed 5-6 times with alkaline water with a pH of 12, and then the organic layer was dried over anhydrous sodium sulfate. After suction filtration, the solvent was distilled off under reduced pressure, and purified by column chromatography to obtain compound 1; Compound 1 and 3-dimethylaminopropylamine were placed in a three-necked flask, a trace amount of KOH solid was added as a catalyst, and magnetic stirring was performed at 90°C for 36 hours. After the reaction was completed, the excess 3-dimethylaminopropylamine was removed by vacuum distillation, and then purified by column chromatography to obtain compound 2; The ethanol solution of compound 2 and bromoethane was placed in a single-necked bottle and magnetically stirred at 90° C. under condensation reflux conditions for 36 hours. After the reaction was completed, the solvent was removed by vacuum distillation, and the sample was purified by recrystallization using ethanol / ethyl acetate to obtain the cationic surfactant.
5. Use of the cationic surfactant according to claim 1 in preparing a viscoelastic solution.
6. A viscoelastic solution, characterized in that The viscoelastic solution is prepared by compounding the cationic surfactant according to claim 1 with sodium octanoate.
7. The viscoelastic solution according to claim 6, wherein The molar ratio of the cationic surfactant to sodium octanoate is in the range of 1:0.5 to 1:
5.
8. A method for preparing the viscoelastic solution according to any one of claims 6 or 7, characterized in that: include: The cationic surfactant is mixed with sodium octanoate.
9. Use of the viscoelastic solution according to any one of claims 6 or 7 in oil production.