A supramolecular compound, a preparation method and application thereof

Abstract

The application provides a supramolecular compound, a preparation method and application thereof, and the supramolecular compound has a structure of formula I. The supramolecular compound provided by the application is formed by counter-ion coupling of an organic acid and an organic base, has extremely high surface activity, and the excellent surface performance endows the supramolecular compound with excellent foamability and foam stability, is beneficial to the stability of a liquid-gas interface, and in addition, the supramolecular compound provided by the application also has good salt resistance and a wide use temperature range, and can meet the application requirements of foam flooding in a high-temperature and high-salt oil field.

Description

Technical Field

[0001] This invention belongs to the field of petrochemical technology, specifically relating to a supramolecular compound, its preparation method, and its application. Background Technology

[0002] Petroleum, often called "liquid gold," is a crucial strategic reserve resource. In recent years, my country's rapid economic development has increased its demand for oil, resulting in a significant shortfall in production. Reliable estimates suggest that my country's oil demand will reach 680 million tons by 2030, with 78% relying on imports. However, the insufficient production is not due to insufficient reserves, but rather because up to 60% of crude oil is trapped in tiny rock fissures, making it difficult to extract using its own pressure or water injection. Therefore, tertiary oil recovery technology—using physical, chemical, or biological methods to alter the properties of the crude oil or its solid / liquid and oil / water interfaces—is essential to improve oil recovery rates. Thus, continuously developing new tertiary oil recovery technologies to enhance crude oil recovery is crucial for alleviating the domestic crude oil supply shortage.

[0003] Foam flooding technology is considered a promising tertiary oil recovery technology due to its excellent plugging and profile control performance and selectivity for oil and water. However, foam is a dispersion system formed by insoluble or slightly soluble gases dispersed in a liquid, often with a very large gas-liquid interface area. This results in a high surface free energy, making it a thermodynamically unstable system, especially at high temperatures. The foam often collapses before the oil displacement process ends, limiting its application in high-temperature oil and gas reservoirs. To overcome this limitation, high-temperature resistant foam systems have been continuously studied, yielding some results. For example, CN104276983A discloses a method for preparing a surfactant for enhancing oil recovery; CN116144377A discloses a novel fluorobetaine surfactant and its preparation method; and CN103666430A relates to a surfactant composition for enhanced oil recovery and its preparation method. However, these surfactants either have complex compositions or cumbersome synthesis processes, which are not conducive to industrial production.

[0004] Therefore, there is an urgent need to develop a compound with excellent surface properties, good foaming properties and salt resistance, which can be prepared by a simple synthesis method. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a supramolecular compound, its preparation method, and its application. Through the design of the supramolecular compound structure, it possesses excellent surface properties, good foaming properties, and salt resistance, which can meet the application requirements of foam flooding in high-temperature and high-salinity oilfields.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a supramolecular compound having a structure shown in Formula I:

[0008]

[0009] Wherein, R1 and R3 each independently selected from a C8-C16 straight-chain or branched-chain alkyl group, any one of; R 11 is selected from any one of a C8-C24 straight-chain alkyl group and a C6-C35 branched-chain alkyl group, and the main-chain carbon number of the C6-C35 branched-chain alkyl group ≤ 24 (for example, the main-chain carbon number can be C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C18, C20, C22, etc.).

[0010] R2 is selected from any one of.

[0011] -* represents the connection site of the group.

[0012] a is an integer selected from 3-15, for example, it can be 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14.

[0013] n is an integer selected from 2-8, for example, it can be 3, 4, 5, 6, 7.

[0014] The supramolecular compound provided by the present invention belongs to a gemini supramolecular compound, which is formed by the counterion coupling of an organic acid and an organic base. The organic base contains two tertiary amine groups, and the tertiary amine groups are connected by a hydrophilic polyoxyethylene ether group. The surface activity of the organic acid and the organic base constituting the supramolecular compound is very low or has no surface activity, but the supramolecular compound formed by the organic acid and the organic base has extremely high surface activity. This excellent surface performance endows the supramolecular compound with outstanding foaming and foam stability, which is beneficial to the stability of the liquid-gas interface. In addition, the supramolecular compound provided by the present invention also has good salt tolerance and has great potential for application in foam flooding, which has far-reaching significance for solving the problem of poor foam flooding effect in high-temperature reservoirs.

[0015] In the present invention, for the description of chemical elements, unless otherwise specified, it includes the concept of isotopes with the same chemical properties. For example, hydrogen (H) includes 1 H (protium), 2 H (deuterium, D), 3 H (tritium, T), etc.; carbon (C) includes 12 C, 13 C, etc.

[0016] In this invention, "each independently" means that when there are multiple subjects, they can be the same or different from each other.

[0017] In this invention, C8-C16 can all be C9, C10, C11, C12, C13, C14, C15, etc.

[0018] C8-C24 can all be C9, C10, C11, C12, C13, C14, C15, C16, C18, C20, C22, C23, etc.

[0019] C6-C35 can all be C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C18, C20, C22, C24, C26, C28, C30, C32, C34, etc.

[0020] In this invention, the C8-C24 straight-chain alkyl group includes, but is not limited to, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, etc.

[0021] The C6-C35 branched alkyl groups, exemplarily including but not limited to 2-decyltetradecyl.

[0022] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0023] As a preferred technical solution, R1 and R3 are each independently selected from C8-C11 (e.g., C9 or C10) straight-chain or branched alkyl groups. Any one of them; where -* represents the linkage site of the group; R 11 It is selected from any one of C8-C24 straight-chain alkyl and C6-C35 branched alkyl, wherein the C6-C35 branched alkyl has a main chain carbon number ≤24; a is selected from an integer from 3 to 15.

[0024] Preferably, R1 and R3 are each independently selected from C8-C11 straight-chain alkyl groups. Any one of them; R 11 Selected from C8-C12 (e.g., C9, C10, or C11) straight-chain alkyl groups, Any one of the following; where -* represents the linking site of the group; a is an integer selected from 3 to 8, for example, 4, 5, 6, 7; x is an integer selected from 8 to 16, for example, 9, 10, 11, 12, 13, 14, 15.

[0025] Preferably, the R11 Selected from C8-C12 straight-chain alkyl groups, Any one of the following; where -* represents the linking site of the group; x is an integer selected from 8-12, for example, it can be 9, 10, or 11.

[0026] In this invention, the group -C x H 2x+1 -C x-2 H 2x-3 Each can be used independently to represent a straight-chain or branched alkyl group.

[0027] Preferably, R2 is selected from... Any one of the following; n is an integer selected from 2 to 5, for example, it can be 3 or 4.

[0028] Preferably, the supramolecular compound includes any one of the following compounds:

[0029]

[0030]

[0031] In a second aspect, the present invention provides a method for preparing a supramolecular compound as described in the first aspect, the method comprising:

[0032] An organic acid having the structure shown in Formula II, an organic acid having the structure shown in Formula III, and an organic base having the structure shown in Formula IV undergo a first reaction to obtain the supramolecular compound, as shown in the following reaction formula:

[0033]

[0034] Among them, R1, R2, and R3 have the same limited range as in Equation I.

[0035] In this invention, R1 or R3 in the organic acid is Time (a and R) 11 Having the same defined range as in Formula I, its preparation method includes:

[0036] fatty alcohol polyoxyethylene ether (structure: The mixture is stirred with NaOH for 40-60 min; chloropropionic acid is added dropwise to the reaction solution, and stirring is continued for 20-50 min after the addition is complete. The temperature is raised to 45-75℃ and stirred for 4-8 h. Then anhydrous ethanol is added, and the reaction is continued for 1.5-3 h. The anhydrous ethanol is removed to obtain the organic acid. The molar ratio of the fatty alcohol polyoxyethylene ether to NaOH is 3:1; the molar ratio of the fatty alcohol polyoxyethylene ether to chloropropionic acid is 1:2.

[0037] In this invention, when R1 in the organic acid having the structure shown in Formula II is a C8-C16 straight-chain or branched alkyl group, the organic acid having the structure shown in Formula II can be obtained by purchase. For example, when R1 is n-decyl, the organic acid having the structure shown in Formula II is lauric acid, which can be purchased from Sinopharm Chemical Reagent Co., Ltd.

[0038] In this invention, the method for preparing the organic base having the structure shown in Formula IV includes:

[0039] A compound having the structure shown in Formula IV-1 undergoes a second reaction with dimethylamine to give the organic base, as shown in the following reaction formula:

[0040]

[0041] In Formula IV-1, R2 has the same limiting range as in Formula I; X1 and X2 are each independently selected from chlorine or bromine atoms.

[0042] Preferably, the second reaction is carried out in the presence of a catalyst.

[0043] Preferably, the catalyst comprises potassium iodide.

[0044] Preferably, the temperature of the second reaction is 50-90°C, for example, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, etc.

[0045] Preferably, the second reaction time is 24-36 hours, for example, 24.5 hours, 25 hours, 25.5 hours, 26 hours, 26.5 hours, 27 hours, 27.5 hours, 28 hours, 28.5 hours, 29 hours, 29.5 hours, 30 hours, 30.5 hours, 31 hours, 32.5 hours, 33 hours, 33.5 hours, 34 hours, 34.5 hours, 35 hours, 35.5 hours, etc.

[0046] Preferably, the second reaction is carried out by programmed temperature increase.

[0047] Preferably, the process further includes a neutralization step after the second reaction is completed.

[0048] Preferably, the neutralizing agent used in the neutralization includes sodium hydroxide and / or potassium hydroxide.

[0049] This invention prepares an organic base containing polyoxyethylene ether groups through a one-step reaction, and utilizes the principle of acid-base reaction to prepare a supramolecular compound containing hydrophilic linking groups by mixing organic acid and organic base in a 2:1 molar ratio. The preparation process is simple and low in cost.

[0050] Preferably, the temperature of the first reaction is 30-95℃, for example, it can be 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, etc.

[0051] Preferably, the reaction time is 20-60 min, for example, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, etc.

[0052] Preferably, the first reaction is carried out in the presence of a solvent.

[0053] Preferably, the solvent includes water.

[0054] Thirdly, the present invention provides an application of a supramolecular compound as described in the first aspect, said supramolecular compound being used as a surfactant.

[0055] Fourthly, the present invention provides a foam displacement agent, wherein the components of the foam displacement agent include supramolecular compounds as described in the first aspect.

[0056] Compared with the prior art, the present invention has the following beneficial effects:

[0057] (1) The supramolecular compound provided by this invention has high surface activity, and its critical micelle concentration is 5.61 × 10⁻⁶. -6 -7.56×10 -5 mol·L -1 The equilibrium surface tension is 24.45-31.93 mN·m. -1 ;

[0058] (2) The supramolecular compound provided by the present invention has extremely strong adsorption properties on the glass surface. When the concentration of the aqueous solution of the supramolecular compound is only 0.05wt%, the contact angle of the aqueous phase can reach 23.4°-28.9°.

[0059] (3) The supramolecular compound provided by the present invention has good foaming properties. At a temperature of 90°C and a concentration of 0.2wt% in the aqueous solution of the supramolecular compound, the comprehensive foaming index can reach 12320-264600, which has excellent performance under high temperature conditions.

[0060] (4) The supramolecular compound provided by the present invention can be used in the temperature range of 0-100℃, with a wide range of applicable temperatures and extremely strong salt resistance. When the supramolecular compound provided by the present invention is added to simulated formation water with a concentration of 7wt%, its light transmittance can reach 99.5%. Attached Figure Description

[0061] Figure 1This is the 1H NMR spectrum of 1,2-bis(2-dimethylaminoethoxy)ethane;

[0062] Figure 2 This is the 1H NMR spectrum of 12-EO2-12;

[0063] Figure 3 It is the 1H NMR spectrum of 24-EO7-EO2-24;

[0064] Figure 4 It is the 1H NMR spectrum of 12-EO8-EO2-12;

[0065] Figure 5 The supramolecular compounds provided in Examples 1-3, C 12 Surface tension curve of EO8COOH;

[0066] Figure 6 This is a schematic diagram of contact angle measurement;

[0067] Figure 7 These are images captured on glass slides after soaking in aqueous solutions of 12-EO2-12 at different concentrations for 24 hours, showing n-decane oil droplets.

[0068] Figure 8 These are images captured on glass slides after soaking in aqueous solutions of different concentrations of 24-EO7-EO2-24 for 24 hours, showing n-decane oil droplets.

[0069] Figure 9 These are images captured on glass slides after soaking in aqueous solutions of different concentrations of 12-EO8-EO2-12 for 24 hours, showing n-decane oil droplets. Detailed Implementation

[0070] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be considered as specific limitations thereof.

[0071] The sources of some components in the following examples and comparative examples are as follows:

[0072] (1) 1,2-bis(2-dimethylaminoethoxy)ethane: The structure is as follows Its preparation methods include:

[0073] Dichlorotriethylene glycol (18.6 g, 0.1 mol) and 200 mL of acetone were placed in a reaction vessel, and potassium iodide (10 mg) and an ethanol solution of dimethylamine (75 g, 0.5 mol, 30%) were added. The reaction was carried out using a programmed temperature ramp for 30 h, i.e., 10 h each at 50 °C, 70 °C, and 90 °C. After the reaction was completed, the solvent was removed by rotary evaporation, and the product was dissolved in 100 mL of ethanol. Sodium hydroxide (8.2 g, 0.205 mol) was added to neutralize the generated hydrogen chloride, and the generated sodium chloride was removed by filtration. The lower layer of liquid was collected, and the solvent was removed by vacuum distillation to obtain a golden-yellow liquid, which was the target product, with a yield of 89.2%.

[0074] Weigh 10 mg of 1,2-bis(2-dimethylaminoethoxy)ethane and place it in an NMR tube. Add deuteration reagent CDCl3 to dissolve it, and then perform NMR analysis using a 400 MHz Aduance III NMR spectrometer at 25 °C. 1 H NMR testing, the test results are as follows Figure 1 As shown, from Figure 1 It can be seen that the chemical shifts of each hydrogen atom are consistent with the target product 1,2-bis(2-dimethylaminoethoxy)ethane, indicating that the final product was obtained; at the same time, the spectrum is relatively clean, indicating that the product has reached a high purity.

[0075] (2) Branched alcohol ether carboxylic acid (C 24 EO7COOH), its structure is:

[0076]

[0077] The branched alcohol ether carboxylic acid (C 24 The preparation methods of EO7COOH include:

[0078] 0.01 mol of branched fatty alcohol polyoxyethylene ether (structure: 0.003 mol NaOH was placed in a flask and stirred for 1 h. 0.02 mol chloropropionic acid was added dropwise to the reaction solution, and stirring continued for 30 min after the addition was complete. The temperature was raised to 60 °C and stirred for 6 h. Anhydrous ethanol was then added, and the reaction continued for 2 h. The anhydrous ethanol was removed from the reaction solution using a rotary evaporator to obtain the C0. 24 EO7COOH.

[0079] (3) Straight-chain alcohol ether carboxylic acid (C 12 EO8COOH), its structure is:

[0080] The straight-chain alcohol ether carboxylic acid (C 12 The preparation methods of EO8COOH include:

[0081] 0.01 mol of linear fatty alcohol polyoxyethylene ether (structure: 0.003 mol NaOH was placed in a flask and stirred for 1 h. 0.02 mol chloropropionic acid was added dropwise to the reaction solution, and stirring continued for 30 min after the addition was complete. The temperature was raised to 60 °C and stirred for 6 h. Anhydrous ethanol was then added, and the reaction continued for 2 h. The anhydrous ethanol was then removed from the reaction solution using a rotary evaporator to obtain the C3. 12 EO8COOH.

[0082] (4) Lauric acid: purchased from Sinopharm Chemical Reagent Co., Ltd.

[0083] Example 1

[0084] A supramolecular compound, 12-EO2-12, has the following structure:

[0085]

[0086] The preparation method of the supramolecular compound 12-EO2-12 includes:

[0087] Add 0.2003 g of lauric acid and 0.1020 g of 1,2-bis(2-dimethylaminoethoxy)ethane to 10 mL of deionized water, and stir at 70 °C for 30 min to obtain a mother liquor containing the supramolecular compound 12-EO2-12 with a concentration of 50 mM.

[0088] Example 2

[0089] A supramolecular compound, 24-EO7-EO2-24, has the following structure:

[0090]

[0091] The preparation method of the supramolecular compound 24-EO7-EO2-24 includes:

[0092] Add 0.7434 g of branched-chain alcohol ether carboxylic acid (C) to 10 mL of deionized water. 24 EO7COOH) and 0.1020 g of 1,2-bis(2-dimethylaminoethoxy)ethane were stirred at 70 °C for 30 min to obtain a mother liquor containing the supramolecular compound 24-EO7-EO2-24 with a concentration of 50 mM.

[0093] Example 3

[0094] A supramolecular compound, 12-EO8-EO2-12, has the following structure:

[0095]

[0096] The preparation method of the supramolecular compound 12-EO8-EO2-12 includes:

[0097] Add 0.6344 g of straight-chain alcohol ether carboxylic acid (C) to 10 mL of deionized water. 12 EO8COOH) and 0.1020 g of 1,2-bis(2-dimethylaminoethoxy)ethane were stirred at 70 °C for 30 min to obtain a mother liquor containing the supramolecular compound 12-EO8-EO2-12 with a concentration of 50 mM.

[0098] Product characterization and performance testing

[0099] (1) Proton NMR spectrum: A certain amount of 1,2-bis(2-dimethylaminoethoxy)ethane and organic acid were weighed and placed in an NMR tube (the specific amounts are shown in Table 1 below). Deuterated reagent D2O was added to dissolve the mixture. Then, the NMR spectrum was obtained using a 400MHz Aduance III NMR spectrometer at 25℃. 1 HNMR testing, the test results are as follows Figure 2 , 3 As shown in Figure 4. From Figure 2 , 3 As can be seen from Figures 4 and 5, the chemical shifts of each hydrogen atom are consistent with the target product, indicating that the final product has been obtained; at the same time, the spectrum is relatively clean, indicating that the product has reached a very high purity.

[0100] Table 1

[0101] organic acids 1,2-Di(2-dimethylaminoethoxy)ethane <![CDATA[12-EO2-12]]> 9.8mg 5mg <![CDATA[24-EO7-EO2-24]]> 14.6mg 2mg <![CDATA[12-EO8-EO2-12]]> 12.4mg 2mg

[0102] (2) Surface performance testing: The Du Noüy ring method was used to test the 50 mM mother liquor containing supramolecular compounds provided in Examples 1-3, and the 50 mM mother liquor containing straight-chain alcohol ether carboxylic acids (C... 12 The equilibrium surface tension of the mother liquor containing EO8COOH. Pour into a clean weighing dish. 16 mL of 18.2 MΩ·cm ultrapure water was added to the solution, and the above-mentioned mother liquor was added dropwise. After equilibration for different time periods, the surface tension was measured using the Du Noüy ring method. Once the surface tension value stabilized, the mother liquor was added again to obtain the surface tension versus concentration curve. The test temperature was 25 ± 0.1℃, and the average value of three measurements was taken. The error should not exceed 0.1 mN·m. -1 Plotting the measured equilibrium surface tension (γ) on the ordinate and the concentration (c) on the abscissa yields the γ-c relationship graph, as shown below. Figure 5 As shown in the figure, the supramolecular compounds and straight-chain alcohol ether carboxylic acids (C) provided in Examples 1-3 can be obtained through this figure. 12 Critical micelle concentration (cmc) and equilibrium surface tension (mN·m) of EO8COOH -1 The results are shown in Table 2 below;

[0103] Table 2

[0104] <![CDATA[Critical micelle concentration (cmc) / mol·L -1 > <![CDATA[Equilibrium surface tension / mN·m -1 > <![CDATA[C 12 EO8COOH]]> <![CDATA[1.46×10 -5 ]]> 32.10 <![CDATA[12-EO2-12]]> <![CDATA[7.56×10 -5 ]]> 24.45 <![CDATA[24-EO7-EO2-24]]> <![CDATA[7.18×10 -6 ]]> 30.12 <![CDATA[12-EO8-EO2-12]]> <![CDATA[5.61×10 -6 ]]> 31.93

[0105] As can be seen from Table 2, compared with C 12 The surface activity parameters of EO8COOH reveal that the supramolecular compound provided by this invention, composed of non-covalent bonds, exhibits low equilibrium surface tension and a critical micelle concentration reaching 10. -6 The equilibrium surface tension can be reduced to 24.45 mN·m, which is on the order of magnitude of [the previous value]. -1 Regarding 12-EO2-12, its surface tension is much smaller than that of C. 12 EO8COOH fully demonstrates its excellent surface properties.

[0106] (3) Foam performance test: The foaming performance and stability of the foam were evaluated using the Waring stirring method according to the China National Petroleum Corporation enterprise standard "Technical Specification for Foaming Agents for Foam Displacement" (Q / SY 17816-2021). The specific method was as follows: 200 mL of supramolecular compound aqueous solution of different concentrations was poured into a measuring cup, stirred at high speed for 60 s, and the solution in the measuring cup was quickly transferred to a measuring cylinder. The volume of the foam (V) and the time required to separate 100 mL of liquid from the foam, i.e., the drainage half-life (t), were recorded. 1 / 2 The composite index FCI = V × t 1 / 2 ;

[0107] The experimental temperature was 90℃, and the experimental water was deionized water. Let V represent the foaming capacity, and t represent the foaming capacity. 1 / 2 This indicates the stability of the foam. The larger the value of V, the stronger the foaming ability of the supramolecular compound. 1 / 2 The larger the value, the better the foam stability; the higher the FCI (Follicular Index), the better the foam performance of the supramolecular compound. The results are shown in Table 3 below:

[0108] Table 3

[0109]

[0110]

[0111] As can be seen from Table 3, 12-EO2-12 exhibits the best foam performance, which is attributed to its equilibrium surface tension value reaching 24.45 mN·m. -1 The foam index was 553,000 when the concentration of the 12-EO2-12 aqueous solution was 0.6 wt%, which fully demonstrates the potential of the supramolecular compound provided by this invention as a foam displacement agent in high-temperature oil reservoirs.

[0112] (4) Wetting performance test: A glass slide with a negatively charged surface was used to simulate the sandstone surface. The contact angle of the oil droplets on the glass slide when the oil droplets coexist with the aqueous phase was measured by the oil droplet (n-decane) method. The contact angle of the aqueous phase was then converted to characterize the wettability of the supramolecular compound on the solid surface. The specific operation is as follows:

[0113] A rectangular glass slide (25mm × 15mm) was uniformly cut, washed, and then soaked in a 30wt% NaOH aqueous solution for 24 hours. After soaking, the slide was carefully removed, rinsed repeatedly under water, and air-dried. A clean, dry glass slide was placed on a support in a rectangular glass trough (35mm (L) × 25mm (D) × 20mm (H)). A supramolecular compound aqueous solution of different concentrations (0.05wt%, 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%) was added to cover the slide. After standing at 25±0.2℃ for 24 hours, the slide was transferred to the stage of a contact angle measuring instrument. At 25℃, a droplet of approximately 1μL was slowly released from a U-shaped needle. The droplet floated and was captured by the glass slide. A schematic diagram of the contact angle measurement is shown below. Figure 6 As shown. Images of the inverted droplet were captured using a contact angle meter (LAUDAS Scientific Dynamic Contact Angle Meter LSA100). The test results are as follows. Figure 7-9 As shown in Table 4 below, the contact angle θ (°) of the aqueous phase was calculated.

[0114] Table 4

[0115] concentration 0.05wt% 0.1wt% 0.2wt% 0.3wt% 0.4wt% <![CDATA[12-EO2-12]]> 28.9 25.1 27.4 27.2 25.4 <![CDATA[24-EO7-EO2-24]]> 27.1 23.7 28.3 22.5 21.6 <![CDATA[12-EO8-EO2-12]]> 23.4 25.7 29 33.7 30.2

[0116] The smaller the contact angle, the stronger the oleophobicity. As can be seen from Table 4, the contact angle of the supramolecular compound provided by the present invention is almost between 25° and 30°, indicating that the glass slide has strong oleophobicity at this time, proving that the supramolecular compound provided by the present invention has good wettability.

[0117] (5) Salt tolerance test: Prepare a simulated formation water mother liquor with a total salinity of 199,674 ppm according to the ion concentrations shown in Table 5:

[0118] Table 5

[0119] ion <![CDATA[Na + ]]> <![CDATA[Mg 2+ ]]> <![CDATA[Ca 2+ ]]> <![CDATA[Cl - ]]> <![CDATA[HCO3 - ]]> <![CDATA[SO4 2- ]]> Total mineralization Content (ppm) 58134 2050 15781 123104 305 300 199674

[0120] By diluting the simulated formation water mother liquor with deionized water, a series of simulated formation waters with low salinity can be obtained. The salinity and mass concentration are shown in Tables 6 and 7 below:

[0121] Table 6

[0122] Mineralization / ppm 199674 149756 99837 89853 79870 69886 Concentration / wt% 20 15 10 9 8 7

[0123] Table 7

[0124] Mineralization / ppm 59902 49919 19967 9984 3993 1997 998 Concentration / wt% 6 5 2 1 0.4 0.2 0.1

[0125] The specific procedure for the salt tolerance test is as follows: A 0.4 wt% solution of the supramolecular compound was prepared in a 25 mL glass bottle using simulated formation water with different mineralization. After dissolving or dispersing evenly, the solution was placed in an 80±0.5℃ incubator for 24 hours. The transmittance T (%) of the solution after standing at 80℃ for 24 hours was measured using a UV-Vis spectrophotometer (LabTech UVPower) under visible light (wavelength 600 nm). The mineralization corresponding to the point where the transmittance of the solution begins to decrease significantly is the salt tolerance of the sample at 80℃. The results are shown in Tables 8-10 below. Table 8 shows the salt tolerance of the sample containing C. 12 The transmittance data of EO8COOH solutions are shown in Table 9, which contains 24-EO7-EO2-24, and Table 10, which contains 12-EO8-EO2-12.

[0126] Table 8

[0127] Concentration / wt% 0.1 0.2 0.4 1 2 5 transmittance / % 99.9 99.9 79.9 48.3 7.6 0.8

[0128] Table 9

[0129] Concentration / wt% 0.1 0.2 1 2 5 10 15 20 transmittance / % 87.2 88.1 86.2 86.7 83.1 85.6 84.3 89.2

[0130] Table 10

[0131] Concentration / wt% 5 6 7 8 9 10 15 20 transmittance / % 99.9 99.8 99.5 96.4 98.6 95.1 97.2 99.2

[0132] As can be seen from Table 8, C 12 EO8COOH has a salt tolerance of less than 1 wt%, compared to C. 12 Even when the concentration of simulated formation water reaches 7 wt%, the transmittance of the EO8COOH solution containing 12-EO8-EO2-12 can still reach 99.5%, which is not much different from the transmittance of deionized water. This indicates that no supramolecular compounds are precipitated at this time, which fully demonstrates that the supramolecular compounds provided by this invention have excellent salt resistance.

[0133] The applicant declares that the above embodiments illustrate the supramolecular compounds, their preparation methods, and applications, but the present invention is not limited to the above embodiments, i.e., it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials for the products of the present invention, addition of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A supramolecular compound, characterized in that, The supramolecular compound has the structure shown in Formula I: Formula I; Among them, R1 and R3 are each independently selected from C8-C16 straight-chain or branched alkyl groups. Any one of them; R 11 It is selected from any one of C8-C24 straight-chain alkyl and C6-C35 branched alkyl, wherein the C6-C35 branched alkyl has ≤24 carbon atoms in its main chain; R2 is selected from , Any one of them; The linking site of the representative group; a is an integer selected from 3 to 15; n is an integer selected from 2 to 8.

2. The supramolecular compound according to claim 1, characterized in that, R1 and R3 are each independently selected from C8-C11 straight-chain or branched alkyl groups. Any one of them; in, The linking site of the representative group; R 11 It is selected from any one of C8-C24 straight-chain alkyl and C6-C35 branched alkyl, wherein the C6-C35 branched alkyl has ≤24 carbon atoms in its main chain; a is an integer selected from 3 to 15.

3. The supramolecular compound according to claim 2, characterized in that, R1 and R3 are each independently selected from C8-C11 straight-chain alkyl groups. Any one of them; R 11 Selected from C8-C12 straight-chain alkyl groups, Any one of them; in, The linking site of the representative group; a is an integer selected from 3 to 8; x is an integer selected from 8 to 16.

4. The supramolecular compound according to claim 3, characterized in that, The R 11 Selected from C8-C12 straight-chain alkyl groups, Any one of them; in, The linking site of the representative group; x is an integer selected from 8 to 12.

5. The supramolecular compound according to claim 1, characterized in that, R2 is selected from Any one of them; n is an integer selected from 2 to 5.

6. The supramolecular compound according to claim 1, characterized in that, The supramolecular compound includes any one of the following compounds: 。 7. A method for preparing a supramolecular compound according to any one of claims 1-6, characterized in that, The preparation method includes: An organic acid having the structure shown in Formula II, an organic acid having the structure shown in Formula III, and an organic base having the structure shown in Formula IV undergo a first reaction to obtain the supramolecular compound, as shown in the following reaction formula: ； Among them, R1, R2, and R3 have the same limited range as in Equation I.

8. The preparation method according to claim 7, characterized in that, The temperature of the first reaction is 30-95℃.

9. The preparation method according to claim 7, characterized in that, The first reaction takes 20-60 minutes.

10. The preparation method according to claim 7, characterized in that, The first reaction is carried out in the presence of a solvent.

11. The preparation method according to claim 10, characterized in that, The solvent includes water.

12. An application of a supramolecular compound as described in any one of claims 1-6, characterized in that, The supramolecular compound is used as a surfactant.

13. A foam oil displacement agent, characterized in that, The components of the foam displacement agent include supramolecular compounds as described in any one of claims 1-6.

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