Synthesis and application of multi-alkyl aromatic alcohol extension type block copolymer and oxysalt of multi-alkyl aromatic alcohol extension type block copolymer

Abstract

The invention discloses a multi-alkyl aromatic alcohol extended block copolymer or oxysalt thereof as well as a synthesis method and application thereof. Molecules of the product contain polyalkyl, aryl, polyoxypropyl / ethyl and various ionic hydrophilic group structures, the product has excellent temperature resistance and salt tolerance and stable chemical properties, the adsorption loss in sandstone is extremely small, any alkaline agent does not need to be added, the crude oil recovery rate can be increased by 40% or above only through a single component at the concentration of 0.3 wt%, and the oil recovery rate can be increased by 30% or above. And the influence of performance degradation of the composite oil-displacing agent in an oil reservoir due to a chromatographic separation effect is avoided.

Description

Technical Field

[0001] The invention discloses the synthesis and application of a polyalkyl aromatic alcohol extended block copolymer and an oxygen-containing salt thereof, and belongs to the technical field of oilfield chemicals. Background Art

[0002] In oilfield development, injecting various chemicals into the reservoir can effectively improve the elution and displacement of crude oil by the injected fluid, thereby increasing crude oil recovery. Amphiphilic substances are particularly effective in reducing interfacial tension between the oil and water phases and promoting the solubilization of crude oil in the injected fluid. To achieve optimal results, these substances are often used in conjunction with alkaline agents, inorganic salts, polymers, and other agents. For specific reservoir conditions, optimized and screened oil displacement agent formulations can generally further increase crude oil recovery by approximately 5-10% over water and polymer flooding. They can also effectively reduce the residual oil saturation of the reservoir and the water content of the produced fluid, thereby extending the production life of the oilfield.

[0003] As the exploitation of oil fields continues to increase, the oil displacement agents currently in use are no longer able to meet the needs of further improving crude oil recovery. The total recovery rate after chemical flooding can generally only reach about 60%, and there is still huge room for improvement. The main reasons that currently restrict the improvement of chemical flooding technology are as follows. First, the salt resistance and adsorption resistance of oil displacement agents are generally insufficient; second, although conventional oil displacement agents such as alkylbenzene sulfonates and petroleum sulfonates can reduce the oil-water interfacial tension to an ultra-low level (<10 -2 mN / m), but often fail to form a middle-phase microemulsion, resulting in limited solubilization of oil and water, making it difficult to further improve oil displacement efficiency. Third, to improve oil displacement efficiency, oil displacement agent formulations often use two or more amphiphilic compounds in combination. However, these compounds are prone to chromatographic separation in porous reservoir media and complex oil-water environments, causing compositional changes during the displacement process and reducing their effectiveness. Fourth, some highly effective oil displacement agents are limited in large-scale use due to high prices or environmental and safety concerns. For example, while alkylphenols and their polyoxyethylene ethers exhibit excellent wetting, emulsification, and solubilization abilities, they are highly toxic, have poor biodegradability, and their degradation metabolites are also toxic. Some countries have gradually restricted or banned their use since the 1980s. Guerbet alcohols, which contain branched alkyl structures, have excellent water solubility and interfacial tension-reducing properties and are often used as the primary raw material in the production of heat-resistant and salt-resistant oil displacement agents abroad. However, their production technology is primarily monopolized by companies such as BASF and Sasol, and their price is four to five times higher than that of conventional oil displacement agents, hindering their widespread use in my country.

[0004] In recent years, many new products and formulation technologies have been continuously developed, but it has always been difficult to simultaneously overcome the above-mentioned bottlenecks, and the scope of application or effectiveness of improving oil recovery remains limited. For example, patent CN111334276A discloses a composite oil displacement system using a hydrophobic alkylbenzene sulfonate and a hydrophilic sulfonate. Although this system can form an ultra-low interfacial tension and long-term stable mesophase microemulsion with crude oil, due to the significant difference in salt resistance between the hydrophobic and hydrophilic sulfonates, chromatographic separation is easily produced in the formation, and therefore it is only suitable for oil displacement in high-temperature, low-salinity reservoirs. Patent CN113881418A discloses an alkylaniline polyether benzene sulfonate oil displacement agent. Although it can achieve ultra-low interfacial tension under alkali-free, high-salinity conditions, the product structure contains amino groups and is alkaline, which can easily lead to problems such as equipment corrosion, scaling, and reservoir pore throat blockage. Adjusting the system pH to neutral or acidic causes the amino groups to become positively charged, causing them to strongly adsorb on the negatively charged surface of sandstone reservoirs, resulting in a large loss of oil displacement agent and failure to achieve the desired effect. Summary of the Invention

[0005] In response to the above-mentioned problems in the prior art, the present inventors conducted intensive research and developed a novel molecular structure and synthesis method for an oil-displacing agent. As a result, they developed and provided a polyalkyl aromatic alcohol extended block copolymer or its oxygenated salt, which can maintain excellent temperature and salt resistance and stable chemical properties while having strong hydrophobicity and lipophilicity, and has extremely small adsorption loss in sandstone. By controlling the number of ionic hydrophilic groups, its hydrophilic-lipophilic balance value can be greatly adjusted to obtain an oil-displacing agent that can greatly improve crude oil recovery. Its displacement ability for paraffin-based, cycloalkyl-based and various types of crude oils with properties between the two is significantly improved. No multi-component compounding is required, thereby avoiding the performance attenuation of the composite oil-displacing agent in the porous medium of the reservoir due to chromatographic separation, thereby completing the present invention.

[0006] Therefore, one of the objects of the present invention is to provide a polyalkyl aromatic alcohol extended block copolymer or an oxo acid salt thereof, which has the structure shown in formula (I), (II), (III) and (IV): , , , , in, R1 to R4 are independently selected from hydrocarbon hydrophobic groups or hydrogen atoms. Preferably, the hydrocarbon hydrophobic groups are C n H 2n+1 , wherein n = an integer of 1 to 18, preferably, the total number of C atoms contained in R1 to R4 is between 4 and 50, preferably 8 to 38; M is a metal ion of an oxoacid salt, preferably, M is an alkali metal ion; x is the number of linking groups CH2, x = 1-15, preferably 1 to 8, y is the number of polyoxypropyl groups, y = 0 to 80, preferably 2 to 40, and z is the number of polyoxyethyl groups, z = 0 to 80, preferably 0 to 40.

[0007] In a further preferred embodiment, x is an integer in the range of 1 to 3, 5 ≤ y ≤ 30, 0 ≤ z ≤ 20.

[0008] A second object of the present invention is to provide a method for synthesizing the above-mentioned polyalkyl aromatic alcohol extended block copolymer or its oxyacid salt, comprising the following steps: (1) Preparation of polyalkyl aromatic alcohols, (2) Polyalkyl aromatic alcohol reacts with alkylene oxide in the presence of a catalyst to obtain a polyalkyl aromatic alcohol extended block copolymer; (3) reacting the polyalkyl aromatic alcohol extended block copolymer (I) with a sulfonating agent, a sulfate agent, or a carboxylating agent, and optionally neutralizing the reaction to obtain an oxyacid salt of the polyalkyl aromatic alcohol extended block copolymer.

[0009] In step (1), α-olefin and aromatic alcohol are reacted in the presence of an acidic catalyst to obtain polyalkyl aromatic alcohol. The α-olefin is C n H 2n , wherein n is a positive integer of 1-50, preferably 4-36, more preferably 8-18; the aromatic alcohol used is a mixture of one or more homologues or isomers of benzyl alcohol, methylbenzyl alcohol, dimethylbenzyl alcohol, trimethylbenzyl alcohol, phenylethyl alcohol, methylphenylethyl alcohol, dimethylphenylethyl alcohol, trimethylphenylethyl alcohol, phenylpropyl alcohol, methylphenylpropyl alcohol, dimethylphenylpropyl alcohol, phenylbutyl alcohol, phenylpentanol, phenylhexanol, phenylheptanol, and phenyloctanol; more preferably, the aromatic alcohol used is a mixture of one or more homologues or isomers of methylbenzyl alcohol, dimethylbenzyl alcohol, phenylethyl alcohol, methylphenylethyl alcohol, and phenylpropyl alcohol.

[0010] The acidic catalyst is a Bronsted acid or a Lewis acid, and can be a liquid or solid acid, such as H2SO4, HF, or AlCl3.

[0011] In step (1), the reaction is carried out at an elevated temperature, for example, at 30-90°C, preferably at 40-70°C. After the reaction is completed, the temperature is lowered, the reaction is neutralized, the insoluble matter is removed by filtration, the reaction is allowed to stand for stratification, and the upper organic phase is distilled to obtain a polyalkyl aromatic alcohol product.

[0012] In step (2), the catalyst is selected from N-heterocyclic carbene or N-heterocyclic carbene ene. Preferably, the molecular structure of the N-heterocyclic carbene (N-heterocyclic carbene ene) is one of the following: NHC1, NHC2, NHO1 and NHO2;

[0013] The alkylene oxide is selected from propylene oxide, ethylene oxide or a mixture thereof.

[0014] In step (2), the mixture of polyalkyl aromatic alcohol and N-heterocyclic carbene (N-heterocyclic carbene ene) is first subjected to vacuum degassing in a high-pressure reactor, and then propylene oxide is introduced. After the propylene oxide is fully fed and reacted, ethylene oxide is introduced for reaction, and finally a polyalkyl aromatic alcohol extended block copolymer having a structure as shown in formula (I) is obtained.

[0015] In step (3), as the sulfonating agent, one or more of SO3, fuming sulfuric acid, concentrated sulfuric acid or chlorosulfonic acid can be used, and a product containing both sulfonate (SO3M) and sulfate (SO4M) hydrophilic groups can be obtained, as shown in formula (II); when the sulfating agent used is aminosulfonic acid, a product containing only sulfate (SO4M) hydrophilic groups can be obtained, as shown in formula (III); when the carboxylating agent used is chloroacetic acid, a product containing only carboxylate (COOM) hydrophilic groups can be obtained, as shown in formula (IV).

[0016] Furthermore, in step (3), after the sulfonation or carboxylation reaction is completed, alkaline solution is added for neutralization, and the pH is preferably adjusted to alkaline solution to obtain a polyalkyl aromatic alcohol extended block copolymer oxyacid salt product. Preferably, the product is neutralized with a NaOH aqueous solution to alkaline, preferably pH = 8~9, to obtain a polyalkyl aromatic alcohol extended block copolymer oxyacid salt product.

[0017] A third object of the present invention is to provide a use of the above-mentioned polyalkyl aromatic alcohol extended block copolymer or its oxygen-containing salt as an oil displacement agent in crude oil production.

[0018] Compared with existing oil displacement agent products and technologies, the present invention has the following beneficial effects: By designing and synthesizing novel polyalkyl aromatic alcohol extended block copolymers and their oxyacid salts containing multiple alkane, aromatic, and polyoxypropyl lipophilic groups, as well as polyoxyethyl, sulfonate, sulfate, or carboxylate hydrophilic groups within the molecule, the copolymers significantly enhance their washability for paraffinic (containing a high proportion of alkanes), cycloalkyl (containing a high proportion of cycloalkanes and aromatics), and crude oils with properties in between. These copolymers can completely replace alkylphenol polyoxyethylene ethers and various high-performance but limited-application high-efficiency oil displacement agents produced using Guerbet alcohols as raw materials. The polyalkyl aromatic alcohol extended block copolymer and its oxyacid salt designed in the present invention can significantly improve crude oil recovery at a concentration of 0.3 wt.%, requiring only a single component. This eliminates the need for multi-component compounding, thus avoiding the performance degradation of the composite oil displacement agent caused by chromatographic separation in porous media of oil reservoirs. The polyalkyl aromatic alcohol extended block copolymer oxyacid salt designed in the present invention contains both nonionic (polyoxyethylene) and anionic (sulfonate and sulfate) hydrophilic groups. It has strong hydrophobicity and lipophilicity while maintaining excellent temperature and salt resistance. The hydrophilic-lipophile balance can be significantly adjusted by controlling the amount of ionic hydrophilic groups simply by adopting different sulfonation or carboxylation processes. The oil displacement agent system formulated with this product has stable chemical properties and is negatively charged under any pH conditions. It has minimal adsorption loss in sandstone reservoirs where chemical flooding is mainly used, does not require the addition of any alkaline agents, and will not damage equipment, pipelines, or formation structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the NMR spectrum of decylmethylbenzyl alcohol prepared in Example 1 (CDCl3 is the solvent); Figure 2 This is the NMR spectrum of decylmethylbenzyloxypolyoxypropylene (8) polyoxyethylene (1) ether prepared in Example 1 (CDCl3 is the solvent); Figure 3 This is the nuclear magnetic spectrum of decylmethylbenzyloxypolyoxypropylene (8) polyoxyethylene (1) ether sodium sulfate prepared in Example 1 (CDCl3 is the solvent); Figure 4 The transmittance of 1 wt.% sample aqueous solutions prepared in Example 1 and Comparative Example 1 varies with NaCl concentration; Figure 5 The transmittance of 1 wt.% sample aqueous solutions prepared in Example 1 and Comparative Example 1 varies with CaCl2 concentration; Figure 6 The sample prepared in Example 1 shows the effect of reducing the interfacial tension between Daqing crude oil and simulated water at different concentrations and salinities; Figure 7 The sample prepared in Comparative Example 1 shows the effect of reducing the interfacial tension between Daqing crude oil and simulated water at different concentrations and salinities. DETAILED DESCRIPTION

[0020] The present invention will be described in further detail below with reference to preferred embodiments. The embodiments of the present invention include but are not limited to the scope represented by the following embodiments.

[0021] According to one aspect of the present invention, there is provided a polyalkyl aromatic alcohol extended block copolymer or an oxo acid salt thereof having a structure as shown in formula (I), (II), (III) and (IV): , , , , In the above formula, R1 to R4 are independently selected from hydrocarbon hydrophobic groups or hydrogen atoms (H), wherein the hydrocarbon hydrophobic groups are preferably C n H 2n+1 , wherein n = an integer of 1 to 18, more preferably, the total number of C atoms contained in R1 to R4 is between 4 and 50, preferably 8 to 38; M is a metal ion of an oxoacid salt, preferably an alkali metal ion; x is the number of linking groups CH2, x = 1-15, preferably 1 to 8, more preferably an integer in the range of 1 to 3; y is the number of polyoxypropyl groups, y = 0 to 80, preferably 2 to 40, more preferably 5 ≤ y ≤ 30; z is the number of polyoxyethylene groups, z = 0 to 80, preferably 0 to 40, more preferably 0 ≤ z ≤ 20.

[0022] According to a second aspect of the present invention, there is provided a method for synthesizing the above-mentioned polyalkyl aromatic alcohol extended block copolymer or its oxo acid salt, comprising the following steps: Step (1) prepares polyalkyl aromatic alcohol.

[0023] In this step, α-olefin and aromatic alcohol are reacted in the presence of an acidic catalyst to obtain polyalkyl aromatic alcohol.

[0024] The α-olefin is C n H 2n , wherein n is a positive integer of 1-50, preferably 4-36, more preferably 8-18.

[0025] The aromatic alcohol is a mixture of one or more homologues or isomers of benzyl alcohol, methylbenzyl alcohol, dimethylbenzyl alcohol, trimethylbenzyl alcohol, phenylethyl alcohol, methylphenylethyl alcohol, dimethylphenylethyl alcohol, trimethylphenylethyl alcohol, phenylpropyl alcohol, methylphenylpropyl alcohol, dimethylphenylpropyl alcohol, phenylbutyl alcohol, phenylpentanol, phenylhexanol, phenylheptanol and phenyloctanol; more preferably, the aromatic alcohol used is a mixture of one or more homologues or isomers of methylbenzyl alcohol, dimethylbenzyl alcohol, phenylethyl alcohol, methylphenylethyl alcohol and phenylpropyl alcohol.

[0026] The acidic catalyst is a Bronsted acid or a Lewis acid, and can be a liquid or solid acid, such as H2SO4, HF, AlCl3 or other liquid / solid acid as a catalyst.

[0027] According to a preferred embodiment of the present invention, the molar ratio of the α-olefin, aromatic alcohol, and acid catalyst is 1:(0.5-20):(0.01-0.8), preferably 1:(2-10):(0.05-0.5). The inventors have discovered that when the aromatic alcohol is in excess relative to the α-olefin, a higher yield can be achieved. For example, the molar amount of methylbenzyl alcohol can be 3-8 times that of n-decene, preferably 4-6 times.

[0028] In step (1), the reaction is carried out at an elevated temperature, for example, at 30-90°C, preferably at 40-70°C; after a period of reaction, for example, 2-10 hours, preferably 3-6 hours, the reaction is terminated, the temperature is lowered, and an alkaline substance, such as sodium hydroxide or potassium hydroxide solution, is preferably added for neutralization, the insoluble matter is removed by filtration, and the mixture is allowed to stand for stratification.

[0029] In the present invention, after separating the aqueous phase in step (1), an upper organic phase is obtained to obtain a crude polyalkyl aromatic alcohol product, which is generally a homologous mixture of polyalkyl aromatic alcohols. Without being bound by any theory, in the process of synthesizing alkylbenzenes by alkylation reaction of α-olefins and (substituted) benzene, the olefin is first protonated to form primary carbon and secondary carbon cation intermediates. During the process, rearrangement of the carbon chain structure also occurs. Subsequently, the carbon cation acts as an electrophilic reagent to attack the benzene ring to complete the alkylation. Therefore, the obtained product is a mixture of several isomers. For this purpose, the obtained crude polyalkyl aromatic alcohol product is subjected to a distillation and cutting operation, and a fraction with a distillation range of 290-460°C, preferably a fraction with a distillation range of 300-350°C, is selected to obtain the polyalkyl aromatic alcohol product; the crude product is subjected to distillation and cutting to obtain a homologous mixture of polyalkyl aromatic alcohols.

[0030] Step (2) polyalkyl aromatic alcohol reacts with alkylene oxide in the presence of a catalyst to obtain a polyalkyl aromatic alcohol extended block copolymer.

[0031] In this step, the catalyst is selected from N-heterocyclic carbene or N-heterocyclic carbene ene. Preferably, the molecular structure of the N-heterocyclic carbene (N-heterocyclic carbene ene) is one of the following: NHC1, NHC2, NHO1 and NHO2:

[0032] The alkylene oxide is selected from propylene oxide, ethylene oxide or a mixture thereof.

[0033] In the present invention, the polyalkyl aromatic alcohol homologous mixture obtained in step (1) is preferably subjected to an addition reaction with propylene oxide and / or ethylene oxide to obtain a polyalkyl aromatic alcohol extended block copolymer as shown in formula (I): , wherein R1, R2, R3, R4, x, y, and z are as defined above.

[0034] According to a preferred embodiment of the present invention, the molar ratio of the polyalkyl aromatic alcohol, propylene oxide, ethylene oxide and N-heterocyclic carbene (N-heterocyclic carbene) in step (2) is 1: (0-40): (0-40): (0.01-0.5), preferably 1: (3-30): (1-10): (0.05-0.2), more preferably 1: (5-20): (1-5): (0.08-0.12).

[0035] In the present invention, the reaction is carried out at 55-65°C and 0.15-0.35 MPa. First, a mixture of a polyalkyl aromatic alcohol and an N-heterocyclic carbene (N-heterocyclic carbene ene) is vacuum degassed in an autoclave. Propylene oxide is then introduced. Once the propylene oxide has been fully added and reacted, ethylene oxide is introduced to produce a polyalkyl aromatic alcohol extended block copolymer.

[0036] Step (3) reacting the polyalkyl aromatic alcohol extended block copolymer (I) with a sulfonating agent, a sulfate agent or a carboxylating agent, and optionally neutralizing the reactant to obtain an oxygenated salt of the polyalkyl aromatic alcohol extended block copolymer.

[0037] In this step, as the sulfonating agent, one or more of SO3, fuming sulfuric acid, concentrated sulfuric acid or chlorosulfonic acid can be used to obtain a product containing both sulfonate (SO3M) and sulfate (SO4M) hydrophilic groups, as shown in formula (II): ; When the sulfating agent used is aminosulfonic acid, a product containing only sulfate (SO4M) hydrophilic groups can be obtained, as shown in formula (III): ; When the carboxylating agent used is chloroacetic acid, a product containing only carboxylate (COOM) hydrophilic groups can be obtained, as shown in formula (IV): .

[0038] According to one embodiment of the present invention, when SO3 is used as the sulfonating agent, a membrane sulfonation device is used, and the molar ratio of the polyalkyl aromatic alcohol extended block copolymer: SO3 is fixed at 1:2.1. SO3 is diluted by mixing with dry air to a gas concentration of 5% and then enters the sulfonation device. The reaction temperature is controlled at 55~60℃, and the residence time of the material in the reaction device is about 2~5 min.

[0039] According to another embodiment of the present invention, when fuming sulfuric acid (25%), concentrated sulfuric acid (98%), chlorosulfonic acid or aminosulfonic acid is used as the sulfonating agent or sulfating agent, a kettle sulfonation device is used, the molar ratio of the polyalkyl aromatic alcohol extended block copolymer to fuming sulfuric acid / concentrated sulfuric acid / chlorosulfonic acid / aminosulfonic acid is 1: (3-5) / (5-10) / (2.1-3) / (1.1-2), the reaction temperatures are 55-65°C, 60-70°C, 25-35°C, 80-90°C, and the reaction time is controlled at 3-4 hours.

[0040] According to another embodiment of the present invention, when chloroacetic acid is used as the carboxylating agent, a kettle-type reaction apparatus is used, the molar ratio of the polyalkyl aromatic alcohol extended block copolymer, chloroacetic acid, and base (NaOH or KOH) is 1:1.2-2:1.2-2, the reaction temperature is 60-70°C, and the reaction time is controlled within 2-3 hours.

[0041] Furthermore, after the sulfonation or carboxylation reaction in step (3) is completed, an alkali solution is added for neutralization, preferably the pH is adjusted to the alkali solution, more preferably the pH is neutralized to 8-9 with a NaOH aqueous solution, to obtain a polyalkyl aromatic alcohol extended block copolymer oxyacid salt product.

[0042] In a third aspect, the present invention provides the use of the polyalkyl aromatic alcohol extended block copolymer and its oxyacid salt as an oil displacement agent in crude oil production.

[0043] According to the present invention, the oil-displacing agent is prepared and used in the following manner, specifically comprising steps (1), (2) and (3): (1) dissolving the polyalkyl aromatic alcohol extended block copolymer or its oxyacid salt product in the injection water of the oil field, and controlling the concentration of the product in the injection water to be within the range of 0.001-1 wt.%, preferably 0.01-0.2 wt.%; (2) Samples are taken from the injection water containing the aforementioned polyalkyl aromatic alcohol extended block copolymer or its oxyacid salt product and dissolved in an inorganic salt such as NaCl or KCl to prepare a series of sample solutions containing different NaCl or KCl concentrations. The prepared solutions are sealed with an equal volume of crude oil in a graduated pipette and thoroughly shaken and mixed in a rotary mixer for 8 hours. The mixture is then removed and placed in a thermostat at reservoir temperature for 72 hours. The solubilization of the crude oil and water in the pipette is observed, and the oil-water solubilization index at different product concentrations and inorganic salt concentrations is recorded. (3) The oil displacement agent is prepared based on the concentration of the product and inorganic salts injected into the water when the maximum oil-water solubility index is achieved.

[0044] By using the polyalkyl aromatic alcohol extended block copolymer or its oxo acid salt of the present invention, the interfacial tension between crude oil and water can be reduced to 10 -2mN / m or less, and the solubility index for crude oil and water can reach over 20.

[0045] The following describes the method through examples.

[0046] In the product performance tests of the embodiments and comparative examples, the experiments were conducted using crude oil from the third oil layer of Daqing Oilfield and simulated formation water (containing 1678 mg of sodium chloride, 2918 mg of sodium bicarbonate, 1872 mg of sodium carbonate, 28 mg of sodium sulfate, 12 mg of calcium chloride, and 102 mg of magnesium chloride per liter of water).

[0047] Example 1: Preparation of Decylmethylbenzyloxypolyoxypropylene (8)polyoxyethylene (1) ether sodium sulfate In a stirred reactor, 1200g of 3-methylbenzyl alcohol and 13.1g of aluminum trichloride were added successively. After the temperature was raised to 55-60°C, 275.5g of n-decene was slowly added for alkylation reaction, and the reaction temperature was controlled not to exceed 65°C. After the addition of materials, the reaction was continued at 60-65°C for 4 hours. After the reaction was completed, the temperature was lowered to 40°C and 20% sodium hydroxide solution was added for neutralization. The insoluble matter was removed by filtration and the lower aqueous phase was separated. The upper material was then transferred to a distillation device for distillation cutting. The fractions with a distillation range of 300-330°C were collected to obtain about 451g of 5-decyl-3-methylbenzyl alcohol. The nuclear magnetic resonance hydrogen spectrum (1H NMR) of the product is as follows Figure 1 As shown, it can be seen that although the product is a mixture of fractions within a certain distillation range, the chemical shift of each hydrogen is consistent with the target product, indicating that it has a very high purity.

[0048] 400 g of the prepared 5-decyl-3-methylbenzyl alcohol and 8 g of N-heterocyclic carbene (NHO1) catalyst were added to the autoclave and vacuum degassing was performed at 60°C to make the vacuum degree in the autoclave reach above -0.09 MPa. Then, 707.2 g of propylene oxide was introduced at 55-65°C for alkoxylation reaction. When all the propylene oxide was added and the reaction was complete, 67.1 g of ethylene oxide was introduced for reaction. The pressure in the autoclave was controlled at 0.15-0.35 MPa. After the reaction was completed, about 1174 g of decylmethylbenzyloxypolyoxypropylene (8) polyoxyethylene (1) ether was obtained. The nuclear magnetic resonance hydrogen spectrum (1H NMR) of the product is as follows: Figure 2 As shown, it can be seen that the chemical shifts of each hydrogen in the product are basically consistent with those of the target product.

[0049] 188.8 g of aminosulfonic acid was used as a sulfating agent, and 23.4 g of urea was added as a catalyst to sulfonate 1000 g of the prepared decylmethylbenzyloxypolyoxypropylene (8) polyoxyethylene (1) ether in a stirred reactor at a reaction temperature of 80-90°C. Immediately after the reaction, the product was neutralized with 20% sodium hydroxide solution to a pH of 8-9, yielding approximately 1102 g of decylmethylbenzyloxypolyoxypropylene (8) polyoxyethylene (1) ether sodium sulfate. The nuclear magnetic resonance hydrogen spectrum (1H NMR) of the product (its anion portion) is shown in FIG. Figure 3 As shown, it can be seen that the chemical shifts of each hydrogen in the product are basically consistent with those of the target product.

[0050] Comparative Example 1: Preparation of Tetradecylsulfonic Aniline Polyoxypropylene (8) Polyoxyethylene (1) Ether Sodium Sulfate In a stirred kettle, add 330g of tetradecylbenzene, slowly add 174.5g of 65% nitric acid and 24g of 98% concentrated sulfuric acid, and maintain the reaction temperature at 30°C. Continue the reaction for 3 hours after the addition of the ingredients. After the reaction is complete, separate the spent acid and unreacted raw materials from the product to yield approximately 303g of tetradecylnitrobenzene.

[0051] 300 g of tetradecylnitrobenzene was added to a high-pressure reactor, and 5 g of a 10% palladium-carbon catalyst was added. The reactor was sealed, and the air in the reactor was replaced with nitrogen five times, and then with hydrogen five times. The temperature was then raised to 60°C, and hydrogenation was started. The pressure in the reactor was controlled not to exceed 4 MPa. The reaction was carried out for 6 hours to obtain approximately 272 g of tetradecylaniline.

[0052] In another autoclave, 270 g of tetradecylaniline and 2.5 g of sodium hydroxide were added and vacuum degassed at 100°C until the vacuum in the autoclave reached above -0.09 MPa. Then, 432.8 g of propylene oxide was introduced at 140-150°C for alkoxylation. After all the propylene oxide had been added and reacted, 41 g of ethylene oxide was introduced for reaction. The pressure in the autoclave was controlled at 0.15-0.35 MPa. After the reaction was completed, the system was purged with nitrogen, cooled, neutralized, and dehydrated to obtain approximately 743 g of tetradecylaniline polyoxypropylene (8) polyoxyethylene (1) ether.

[0053] Add 700g of tetradecylaniline polyoxypropylene (8) polyoxyethylene (1) ether to a stirred reactor, then slowly add 250g of fuming sulfuric acid (25%) dropwise. Control the reaction temperature to 55-60°C. Continue the reaction for 1 hour after the addition is complete. After the reaction is completed, let it stand at 50°C for 30 minutes to separate the excess waste acid. Then, immediately neutralize the product with 20% sodium hydroxide solution to a pH of 8-9 to obtain approximately 839g of tetradecylsulfonic acid aniline polyoxypropylene (8) polyoxyethylene (1) ether sodium sulfate.

[0054] Example 2: Salt tolerance test The samples prepared in Example 1 and Comparative Example 1 were respectively dissolved in aqueous NaCl solutions of different concentrations (10,000-300,000 mg / L). The sample concentration was fixed at 1 wt.%. The transmittance of the solution was measured at a wavelength of 600 nm using a spectrophotometer. The transmittance values ​​were plotted against the NaCl concentration in the solution to obtain the following: Figure 4 The curve shown. At lower salt concentrations, the sample solutions are clear and transparent, with a transmittance of more than 90%. When the salt concentration in the solution exceeds the salt tolerance limit of the sample, the solution transmittance drops sharply as the salt concentration continues to increase. The turning point of the solution transmittance change is determined as the maximum tolerance of the sample to the inorganic salt, which can be used to quantitatively characterize its salt tolerance. Figure 4 It can be seen that the sample prepared by the method of Example 1 has good salt tolerance, and the salt tolerance to NaCl can reach about 150,000 mg / L.

[0055] Similarly, the above samples were dissolved in different concentrations (1,000~35,000 mg / L) of CaCl2 aqueous solution to test the salt tolerance of the samples to high-valent cations in hard water. The results are as follows: Figure 5 At a concentration of 1 wt.%, the salt tolerance of the sample prepared by the method of Example 1 to CaCl2 can reach about 15,000 mg / L, indicating that it also has good salt tolerance to high-valent cations in hard water.

[0056] Example 3: Oil sand adsorption resistance test The samples prepared in Example 1 and Comparative Example 1 were prepared into a solution with a concentration of 0.3 wt.% using Daqing simulated water. 5 g of dried Daqing oil sand (70-100 mesh) was weighed and placed in a 100 mL stoppered triangular flask. 45 g of the prepared 0.3 wt.% sample solution was added at a solid-liquid ratio of 1 / 9, and the stoppered triangular flask was shaken until the oil sand and the sample solution were fully mixed. The stoppered triangular flask was then sealed with a bottle stopper and tape, shaken at a constant speed in a constant temperature shaker at 45 ° C for 24 h, and then allowed to stand for 30 min until obvious stratification occurred, and the upper liquid was removed. The removed upper liquid was centrifuged at 8000 rpm for 10 minutes to completely separate the solid particles remaining in the liquid from the solution.

[0057] High-performance liquid chromatography (HPLC) was used to determine the concentration of the sample in aqueous solution. An XBridge C18 reversed-phase column (5.0 μm, 4.6 × 150 mm column) was used; the column temperature was 35 ± 5°C; the injection volume was 10 μL; the mobile phase flow rate was 0.8 mL / min; the mobile phase consisted of 70% acetonitrile and 30% water. The integrated area internal standard method was used. The sample was first prepared with Daqing simulated water to concentrations of 0.05 wt.%, 0.10 wt.%, 0.15 wt.%, 0.20 wt.%, 0.25 wt.%, and 0.30 wt.%. The sample was injected according to the HPLC conditions. The relationship between the integrated area of ​​the chromatographic peak and the sample concentration was obtained, and a standard curve was established. Sample solutions were obtained before and after adsorption of Daqing oil sands. The changes in sample concentration were determined by HPLC. The adsorption of the sample in Daqing oil sands was calculated according to the following formula:

[0058] Where: η—adsorption capacity (mg / g); C 1—initial concentration of the sample before adsorption (wt.%); C 2—equilibrium concentration of the sample after adsorption (wt.%); m 0—mass of adsorbed solution (g); G —Mass of oil sands (g).

[0059] Table 1 shows the adsorption amount of the samples prepared in Example 1 and Comparative Example 1 in Daqing oil sands. It can be seen that the sample prepared by the method of Example 1 has a strong anti-adsorption property to Daqing oil sands, which can greatly reduce its loss during the oil displacement process.

[0060] Table 1

[0061] Example 4: Test on reducing oil-water interfacial tension performance The oil-water interfacial tension reduction performance of the samples prepared in Example 1 and Comparative Example 1 was tested using a TX-500 spinning drop ultra-low interfacial tension meter. The equilibrium interfacial tension of the samples at different concentrations and salinities (NaCl concentrations) was measured using Daqing crude oil and simulated water. Specifically, a drop of Daqing crude oil and approximately 2 mL of simulated water with varying NaCl concentrations were added to a test tube. The interfacial tension between the crude oil and water was measured by observing the shape of the oil droplet under high-speed centrifugal force. The results are shown in Table 1. Figure 6 and Figure 7As shown in the figure, the sample prepared by the method of Example 1 can reduce the oil-water interfacial tension to an ultra-low range (< 0.01 mN / m) at a lower concentration (0.01 wt.%). In the concentration range of 0.01 to 1 wt.%, the oil-water interfacial tension can be reduced to below 0.0001 mN / m, demonstrating excellent interfacial performance.

[0062] Example 5: Oil-water solubilization performance test The microemulsion phase method was used to test the oil-water solubilization abilities of the samples prepared in Example 1 and Comparative Example 1. Daqing crude oil and 0.3 wt.% sample solutions prepared with Daqing simulated water containing varying concentrations of NaCl were sealed in graduated pipettes at an oil / water volume ratio of 1:1. The mixture was mixed and emulsified at 45°C and allowed to stand for 72 hours before reaching equilibrium. The oil-water solubilization index of the sample was calculated using the following formula based on the volume of each phase. At the optimal NaCl concentration, the sample's oil-water solubilization index was equal, indicating maximum oil-water solubilization ability.

[0063] ,

[0064] σ o and σ w are oil / water solubilization index, respectively; V O and V W are the oil / water solubilization volumes, ml, respectively; V S is the surfactant volume, ml.

[0065] Table 2 shows the optimal oil / water solubilization indices for Daqing crude oil and simulated water for the samples prepared in Example 1 and Comparative Example 1. It can be seen that the sample prepared using the method of Example 1 has an oil / water solubilization capacity exceeding 20, significantly higher than that of the sample in Comparative Example 1. This is because the amine functional groups form a double-chain structure when polyoxypropyl and polyoxyethylene groups are added, resulting in a shortened molecular size and a weakened ability to extend at the oil-water interface, limiting their oil-water solubilization performance. In contrast, the aromatic alcohol structure provided in the present invention, when polyoxypropyl and polyoxyethylene groups are added, only a single long chain is formed, which facilitates the product's extension from the interface into both the oil and water phases, significantly improving its oil-water solubilization capacity.

[0066] Table 2 sample Example 1 Comparative Example 1 Solubility Index 22.5 11.6 Example 6: Oil displacement performance test Oil displacement tests were conducted using Bailey cores at 45°C to test the oil displacement effectiveness of samples prepared in Example 1 and Comparative Example 1. The injection method was: polymer flooding + 0.3 PV of oil-displacing agent-polymer dual primary slug (with NaCl added for optimal solubilization) + 0.2 PV of subsequent polymer slug. In all tests, the oil-displacing agent concentration was fixed at 0.3 wt.%, and the polymer used was polyacrylamide (molecular weight 12-16 million) at a concentration of 2000 mg / L. The experimental results are shown in Table 3. As can be seen, the sample prepared in Example 1 further improved the oil recovery by over 40 percentage points over polymer flooding, bringing the total recovery to approximately 90%. The sample prepared in Comparative Example 1 only improved the oil recovery by approximately 22% over polymer flooding. By collecting the displacement effluent and detecting the oil-displacing agent content therein by HPLC, it was found that the total amount of the sample of Comparative Example 1 detected after oil displacement was only about 17% of the total amount before oil displacement, while the retention rate of the sample of Example 1 in the effluent after oil displacement was still able to reach more than 60%. It can be seen that its outstanding oil displacement effect is mainly due to its excellent anti-oil sand adsorption performance, oil-water interfacial tension reduction performance and oil-water solubilization ability.

[0067] Table 3

[0068] The present invention has been described in detail above with reference to specific embodiments and / or exemplary examples and the accompanying drawings. However, these descriptions should not be construed as limiting the present invention. Those skilled in the art will appreciate that various equivalent substitutions, modifications, or improvements may be made to the technical solutions and implementations of the present invention without departing from the spirit and scope of the present invention, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A polyalkyl aromatic alcohol extended block copolymer or an oxyacid salt thereof, characterized in that: Having a structure as shown in formula (I), (II), (III) or (IV): ， ， ， ， In the above formula, R1 to R4 are independently selected from hydrocarbon hydrophobic groups or hydrogen atoms, M is the metal ion of the oxyacid salt, x is the number of CH2 linking groups, y is the number of polyoxypropyl groups, and z is the number of polyoxyethyl groups.

2. The polyalkyl aromatic alcohol extended block copolymer or its oxygen-containing salt according to claim 1, characterized in that: The hydrocarbon hydrophobic group is C n H 2n+1 , wherein n = an integer of 1 to 18, preferably, the total number of C atoms contained in R1 to R4 is between 4 and 50, preferably 8 to 38, M is an alkali metal ion.

3. The polyalkyl aromatic alcohol extended block copolymer or its oxygen-containing salt according to claim 1 or 2, characterized in that: x = 1-15, preferably 1-8, y = 0-80, preferably 2-40, z = 0-80, preferably 0-40.

4. The method for synthesizing the polyalkyl aromatic alcohol extended block copolymer or its oxo acid salt according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1), preparation of polyalkyl aromatic alcohols, (2) Polyalkyl aromatic alcohol reacts with alkylene oxide in the presence of a catalyst to obtain a polyalkyl aromatic alcohol extended block copolymer; (3) reacting the polyalkyl aromatic alcohol extended block copolymer (I) with a sulfonating agent, a sulfate agent or a carboxylating agent, and optionally neutralizing the reactant to obtain an oxyacid salt of the polyalkyl aromatic alcohol extended block copolymer.

5. The synthesis method according to claim 4, characterized in that In step (1), Using α-olefins and aromatic alcohols as reactants, in the presence of an acidic catalyst, the reaction produces polyalkyl aromatic alcohols. The α-olefin is C n H 2n , wherein n is a positive integer of 1-50, preferably 4-36, more preferably 8-18, The aromatic alcohol is a mixture of one or more homologues or isomers of benzyl alcohol, methylbenzyl alcohol, dimethylbenzyl alcohol, trimethylbenzyl alcohol, phenylethyl alcohol, methylphenylethyl alcohol, dimethylphenylethyl alcohol, trimethylphenylethyl alcohol, phenylpropyl alcohol, methylphenylpropyl alcohol, dimethylphenylpropyl alcohol, phenylbutyl alcohol, phenylpentanol, phenylhexanol, phenylheptanol, and phenyloctanol; more preferably, the aromatic alcohol used is a mixture of one or more homologues or isomers of methylbenzyl alcohol, dimethylbenzyl alcohol, phenylethyl alcohol, methylphenylethyl alcohol, and phenylpropyl alcohol; The acidic catalyst is a Bronsted acid or a Lewis acid, and can be a liquid or solid acid, such as H2SO4, HF, or AlCl3.

6. The synthesis method according to claim 4 or 5, characterized in that In step (1), The reaction is carried out at an elevated temperature, for example, at 30 to 90°C, preferably at 40 to 70°C; After the reaction is completed, the temperature is lowered, the mixture is neutralized, the insoluble matter is removed by filtration, the mixture is allowed to stand for stratification, and the upper organic phase is distilled to obtain a polyalkyl aromatic alcohol product.

7. The synthesis method according to any one of claims 4 to 6, characterized in that In step (2), The catalyst is selected from N-heterocyclic carbene or N-heterocyclic carbene, The alkylene oxide is selected from propylene oxide, ethylene oxide or a mixture thereof, The polyalkyl aromatic alcohol extended block copolymer has a structure as shown in formula (I).

8. The synthesis method according to any one of claims 4 to 7, characterized in that In step (3), As the sulfonating agent, one or more of SO3, fuming sulfuric acid, concentrated sulfuric acid or chlorosulfonic acid can be used to obtain a product containing both sulfonate (SO3M) and sulfate (SO4M) hydrophilic groups, as shown in formula (II); When the sulfating agent used is aminosulfonic acid, a product containing only sulfate (SO4M) hydrophilic groups can be obtained, as shown in formula (III); When the carboxylating agent used is chloroacetic acid, a product containing only carboxylate (COOM) hydrophilic groups can be obtained, as shown in formula (IV).

9. The synthesis method according to any one of claims 4 to 8, characterized in that In step (3), After the sulfonation or carboxylation reaction is completed, alkaline solution is added for neutralization, and the pH is preferably adjusted to alkaline solution to obtain the polyalkyl aromatic alcohol extended block copolymer oxyacid salt product.

10. Use of the polyalkyl aromatic alcohol extended block copolymer or its oxo acid salt according to any one of claims 1 to 3 as an oil displacement agent in crude oil production.

Images