CN112708410A

CN112708410A - Composite surfactant containing aryl alcohol polyether anionic nonionic surfactant

Info

Publication number: CN112708410A
Application number: CN201911020212.5A
Authority: CN
Inventors: 吴欣悦; 张卫东; 沙鸥; 李应成; 鲍新宁; 金军
Original assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Current assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Priority date: 2019-10-25
Filing date: 2019-10-25
Publication date: 2021-04-27
Anticipated expiration: 2039-10-25
Also published as: CN112708410B

Abstract

The invention relates to a composite surfactant containing aryl alcohol polyether anionic nonionic surfactant. Mainly solves the problem that the compound oil displacement agent in the prior art is difficult to effectively improve the recovery ratio under the condition of high-temperature and high-salinity oil reservoir. The invention adopts a composite surfactant which comprises the following components in parts by weight: (1) 0.01-1.0 part of alkyl polyether quaternary ammonium salt surfactant; (2) 0.02-1.0 part of aryl alcohol polyether acid salt surfactant; wherein the molecular general formula of the alkyl polyether quaternary ammonium salt surfactant is shown as a formula (I); the molecular general formula of the aryl alcohol polyether acid salt surfactant is shown in formula (II), so that the problem is solved well, and the aryl alcohol polyether acid salt surfactant can be used in tertiary oil recovery production of an oil field.

Description

Composite surfactant containing aryl alcohol polyether anionic nonionic surfactant

Technical Field

The invention relates to a composite surfactant containing aryl alcohol polyether anionic nonionic surfactant.

Background

Petroleum is an important non-regenerative strategic resource, plays an important role in the energy structure of China, is also an important raw material in chemical industry, and has important significance for national economic construction. Because of the severe situation of yield decrement of developed main oil fields in China, the complex types of oil and gas reservoirs without using reserves are proved, particularly the proportion of high-temperature high-salt oil reservoirs, heavy oil extra-heavy oil and low-permeability extra-low-permeability oil reservoirs (which are collectively called as severe oil reservoirs) which are already used and are about to be used is gradually increased, and the development by utilizing the prior art is very difficult, so that the development of a new exploitation technology is urgently needed, the recovery ratio of old oil fields is greatly improved, and the utilization ratio of proved resources is greatly improved, so that the requirements of economic development and national safety are met.

Surfactant flooding is one of the current major research directions for enhanced oil recovery from tertiary recovery. The surfactant can effectively reduce the oil-water interfacial tension, change the oil reservoir wettability, solubilize the crude oil and reduce the crude oil viscosity, and plays an important role in tertiary oil recovery. The anion and cation compound surfactant is used as a new surfactant mixed system and shows special performance in many fields. The strong electrostatic interaction exists between the cationic surfactant and the anionic surfactant, so that the complex system has lower critical micelle concentration, limited occupied area and better interfacial activity, has good capability of forming microemulsion, and is beneficial to obtaining and stabilizing ultra-low interfacial tension. Meanwhile, the formation of the anion-cation pairs greatly enhances the adsorption resistance and calcium and magnesium ion resistance of the anion-cation compound surfactant, and improves the oil displacement effect of the system in a high-temperature and high-salinity oil reservoir.

At present, the anion-cation compound surfactant is less applied in the third mining. Patent CN103773347A reports a composite surfactant composition composed of alkyl polyoxyethylene ether anionic surfactant containing aromatic rings and tetraalkyl quaternary ammonium salt, and the composition has good interfacial properties for the oil field in south of Henan; korea xia et al (journal of physical chemistry, 2012, 28(1), 146-. Patent CN107573916A reports a polymer made of an anionic groupThe oil displacement composition composed of the surfactant, the cationic surfactant and the cosurfactant can be used for oil displacement under a very low use concentration, but the system is complex, the use temperature is not higher than 65 ℃, and the mineralization degree is less than 2000 mg/L. Patent CN104650841A reports that the anion-cation composite surfactant oil displacement agent has ultralow oil-water interfacial tension and good emulsification stability to crude oil, but the use temperature is room temperature and the universality is not high. Patent CN104099077A reports a composition formed by compounding xanthan gum, anionic nonionic surfactant and anionic amphoteric surfactant, which is called to be capable of tolerating total mineralization degree of 32000-^-2An order of magnitude. Patent CN102161883A reports a compound chemical oil displacement agent for tertiary oil recovery in oil field, which comprises anionic surfactant, cationic surfactant and nonionic surfactant, wherein the formation of cation and anion pairs enables the compound chemical oil displacement agent to form a compact interface adsorption film, and the addition of the nonionic surfactant improves the stability of the compound chemical oil displacement agent in hypersalinity water, so that the compound chemical oil displacement agent is not easy to precipitate. Patent CN109652048A provides a composite oil-displacing agent and a preparation method and application thereof, wherein the composite oil-displacing agent comprises a symmetric alkyl alcohol polyoxyethylene ether sulfonate anionic-nonionic surfactant, a cationic surfactant and the balance of water, and the composite oil-displacing agent can remarkably reduce the oil-water interfacial tension, particularly can generate ultralow interfacial tension for low-permeability oil reservoirs, but the temperature resistance of the composite oil-displacing agent needs to be improved.

In order to solve the problem that the compound oil displacement agent in the prior art is difficult to effectively improve the recovery ratio under the condition of high-temperature and high-salt oil reservoir and further improve the temperature resistance and salt resistance and the oil displacement efficiency of the surfactant, the invention adopts the cationic quaternary ammonium salt containing polyether nonionic segments to be compounded with the anionic and nonionic segments, compared with the cationic surfactant without nonionic segments, the cationic nonionic surfactant shows more excellent salt resistance, is more favorable for accurately regulating and controlling the hydrophilic, oleophilic, temperature resistance and salt resistance of the compound surfactant, and obtains the compound oil displacement agent with wider application range and higher oil displacement efficiency.

Disclosure of Invention

The invention aims to solveThe composite surfactant containing the aryl alcohol polyether anionic nonionic surfactant and the alkyl polyether quaternary ammonium salt surfactant can greatly improve the recovery ratio under the conditions of high temperature and high salt oil reservoir. The composite surfactant can form 10 with crude oil under the conditions of wide concentration range, high temperature and high salinity oil reservoir^-2～10^-4mN/m low interfacial tension, thereby improving the oil displacement efficiency of the oil displacement agent.

The invention also provides a preparation method of the composite surfactant capable of improving the recovery ratio, which is used for solving the technical problem.

The invention also provides a method for improving the recovery efficiency of the oil field oil extraction by using the composite surfactant.

In order to solve one of the above technical problems, the technical scheme adopted by the invention is as follows: the composite surfactant for improving the recovery efficiency of crude oil comprises the following components in parts by mass:

(1) 0.01-1.0 part of alkyl polyether quaternary ammonium salt surfactant;

(2) 0.02-1.0 part of aryl alcohol polyether acid salt surfactant;

wherein the molecular general formula of the alkyl polyether quaternary ammonium salt surfactant is shown in a formula (I):

the molecular general formula of the aryl alcohol polyether acid salt surfactant is shown as the formula (II):

in the formula, R₁Is C₁～C₅₀Alkyl groups of (a); r₂、R₃、R₄Is independently selected from C₁～C₄Alkyl or substituted alkyl of (a); r₅Is C₁～C₃₀Alkyl, aryl, SO₃M or COON; r₆Is selected from C₁～C₄An alkylene group or a substituent-containing alkylene group of (a); r₇、R₈Is independently selected from C₁～C₁₀An alkylene group or a substituent-containing alkylene group of (a); x is selected from anions which render the molecule of formula (I) electrically neutral, j is the reciprocal of the absolute value of the valence of X; y is selected from-SO₃Any of M or-COON; m, N is selected from a cation or a cationic group; a. m is the addition number of the propoxy groups, a is 0-10, and m is 0-20; b. n is the sum of ethoxy groups, b is 1-10, and n is 0-20.

In the above technical scheme, when X is preferably a-1 valent anion, the molecular general formula of the alkyl polyether quaternary ammonium salt surfactant is represented by formula (III):

in the above technical scheme, R₁Preferably C₁～C₂₀Alkyl groups of (a); said R₂、R₃、R₄Independently selected as C₁、C₂、C₃Alkyl or hydroxy-substituted alkyl of (a); further preferred is R₁Is C₈、C₉、C₁₀、C₁₁、C₁₂、C₁₃、C₁₄、C₁₅、C₁₆、C₁₇Or C₁₈Alkyl of (2), R₂、R₃Is methyl and/or ethyl, R₄Is C₁、C₂、C₃Alkyl or hydroxy-substituted alkyl. .

In the above technical scheme, R₅Preferably C₁～C₂₀Alkyl, aryl, COON or SO of₃M，R₆Is C₁～C₄Alkylene or hydroxy-substituted alkylene of (A), R₇、R₈Is C₁～C₁₀Alkylene or hydroxy-substituted alkylene of (3), more preferably R₅Is C₈、C₉、C₁₀、C₁₁、C₁₂、C₁₃、C₁₄、C₁₅、C₁₆、C₁₇、C₁₈Alkyl, COON or SO₃M；R₆、R₇、R₈Is C₁、C₂、C₃An alkylene group of (a).

In the above technical solution, the X is preferably a halogen ion, and more preferably-Cl^—、-Br^—、-I^—At least one of (1).

In the above-described embodiment, it is further preferable that a is 0 to 5, b is 5 to 8, m is 0 to 10, and n is 2 to 10.

In the technical scheme, the mass ratio of the aryl alcohol polyether acid salt surfactant to the alkyl polyether quaternary ammonium salt surfactant is preferably 25-1, more preferably 15-1, even more preferably 10-1, more preferably 8-1, even more preferably 5-1, and most preferably 2.5-1.

In the above technical solution, the M, N is preferably at least one selected from ammonium ions and alkali metal ions.

In the technical scheme, the composite surfactant for improving the crude oil recovery rate further comprises 98.0-99.98 parts by mass of injected water.

In the technical scheme, the total mineralization degree of the injected water is preferably 100000-300000 mg/L and Ca²⁺+Mg²⁺Preferably 0 to 7000 mg/L.

In the above technical solution, X is^—Is preferably-Cl^—。

In order to solve the second technical problem, the invention adopts the technical scheme that: a method for preparing an enhanced oil recovery composite surfactant according to any one of the above technical solutions to solve the technical problems, comprising the steps of:

(a) preparation of aryl alcohol polyether acid salt

HO- [ CH (CH)₃)CH₂O]-[CH₂CH₂O]-R₆Y and

reacting at 100-180 ℃ in the presence of a catalyst, then adding water for dilution, carrying out oil-water separation, and obtaining aryl alcohol polyether acid salt in a water phase;

(b) preparation of alkyl polyoxyethylene polyoxypropylene ether

R is to be₄Performing alkoxylation reaction on OH and required amount of propylene oxide and ethylene oxide in the presence of an alkaline catalyst to obtain the alkyl polyoxyethylene polyoxypropylene ether;

(c) halogenation of alkylpolyoxyethylene polyoxypropylene ethers

Mixing the alkyl polyoxyethylene polyoxypropylene ether synthesized in the step (c) with a halogenating reagent for halogenating reaction to obtain halide of the alkyl polyoxyethylene polyoxypropylene ether;

(d) preparation of alkyl polyether quaternary ammonium salt

Will (R)₁R₂R₃) N and the halogenated alkyl polyoxyethylene polyoxypropylene ether synthesized in the step (c) are subjected to quaternization reaction; after the reaction is finished, evaporating the solvent to obtain the product alkyl polyether quaternary ammonium salt;

(e) and (3) mixing the aryl alcohol polyether acid salt synthesized in the step (a), the alkyl polyether quaternary ammonium salt synthesized in the step (d) and injected water according to the required proportion, stirring, and adjusting the pH value to 7-10 to obtain the required composite surfactant.

In the above technical solution, in the step (a), wherein the HO- [ CH (CH)₃)CH₂O]-[CH₂CH₂O]-R₆Y and

the molar ratio is preferably 1 (2-5), the catalyst is preferably an alkaline catalyst, more preferably an alkali metal hydroxide, and most preferably sodium hydroxide, and the amount of the catalyst is 1

1 to 3 wt% of the mass.

In the above technical scheme, in the step (b), the addition sequence of the propylene oxide and the ethylene oxide is preferably that the propylene oxide and the ethylene oxide are added firstlyAdding propylene oxide and then adding ethylene oxide; the amount of the basic catalyst is preferably R₄1-3 wt% of OH; the reaction conditions of the alkoxylation reaction are preferably: the reaction temperature is preferably 100-180 ℃, and the reaction pressure is preferably less than 0.60MPa gauge pressure.

In the above technical scheme, in the step (c), the halogenation temperature is preferably 25-80 ℃; the halogenating agent is preferably triphenylphosphine and carbon tetrachloride.

In the above technical solution, in the step (d), the solvent is preferably at least one selected from ethanol and isopropanol; the quaternization reaction is preferably carried out in a solvent, and the pH value of the reaction is 9-10; the reaction temperature is preferably 60-80 ℃, and the reaction time is preferably 10-16 hours; said (R)₁R₂R₃) The molar ratio of N to alkylpolyoxyethylene polyoxypropylene ether halide is preferably (1-1.2): 1, more preferably 1.1: 1.

In the above technical scheme, in the step (e), the stirring time is preferably 1 to 30 minutes, and the pH value is 8 to 9.5.

In the above technical scheme, in the step (e), the preferable range of the usage amount of the aryl alcohol polyether acid salt is 0.1 to 0.3 wt%, and the preferable range of the alkyl polyether quaternary ammonium salt surfactant is 0.02 to 0.15 wt%, based on the total mass percentage of the system.

In order to solve the third technical problem, the invention adopts the technical scheme that: the use of the enhanced oil recovery composite surfactant according to any one of the above technical solutions to solve the technical problems in oil recovery in an oil field.

In the above technical solution, the application method can be used by those skilled in the art according to the prior art, for example, but not limited to, injecting the composite surfactant solution into an oil reservoir to contact with the underground crude oil, and displacing the underground crude oil; or be used together with other oil production agents.

In the technical scheme, the application method comprises the following steps that the preferred range of the dosage of the aryl alcohol polyether acid salt is 0.1-0.3 wt%, and the preferred range of the alkyl polyether quaternary ammonium salt surfactant is 0.02-0.15 wt%.

According to the invention, the anion-nonionic and cation-nonionic composite surfactants are adopted, and after the anion-nonionic and cation-nonionic surfactants are compounded, the problems of loose arrangement of an interface film and the like caused by electrostatic repulsion among the same charges of the traditional surfactants can be avoided, so that the interfacial activity of the compounded agent is enhanced, and the oil displacement efficiency is improved. Meanwhile, the adsorption resistance and calcium and magnesium ion resistance of the composite surfactant are enhanced, so that the composite surfactant has the possibility of being applied to high-salinity oil reservoirs.

The composite surfactant capable of improving the recovery efficiency can be used for the formation with the temperature of 90 ℃ and the mineralization degree of 20 multiplied by 10⁴mg/L of Jianghham formation water and crude oil, wherein the dosage of the compound surfactant oil displacement agent is formed by 0.1-0.3 wt% of aryl alcohol polyether acid salt and 0.02-0.15 wt% of alkyl polyether quaternary ammonium salt, the dynamic interfacial tension between the oil displacement agent aqueous solution and the Jianghham crude oil is measured, and can reach 10%^-3～10^-4The ultra-low interfacial tension of mN/m obtains better technical effect, and can be used for improving the recovery ratio of tertiary oil recovery.

The invention is further illustrated by the following examples.

Detailed Description

[ example 1 ]

(1) HO- [ CH (CH)₃)CH₂O]-[CH₂CH₂O]-R₆Y and

adding sodium hydroxide as a catalyst into a reaction kettle, introducing nitrogen to react at 150-180 ℃ under the pressure of 20kg/L, wherein HO- [ CH (CH)₃)CH₂O]-[CH₂CH₂O]-R₆Y、

The catalyst molar ratio is 1: 2: 1.5, adding water for dilution, performing oil-water separation, and obtaining aryl alcohol polyoxyethylene polyoxypropylene etherate from a water phase;

(2) adding a certain amount of R into a polymerization reaction kettle₄OH and with R₄OH weightCalculating 1% KOH, heating the system to 80-90 ℃ under stirring, starting a vacuum system, dehydrating for 1 hour under high vacuum, purging with nitrogen for 3-4 times to remove air in the system, adjusting the reaction temperature of the system to 130 ℃, and slowly introducing propylene oxide with calculated amount to control the reaction pressure<And (3) carrying out propoxylation alkylation reaction at 0.40MPa, continuing to slowly introduce a calculated amount of ethylene oxide after the reaction is finished, purging the system by using nitrogen after the reaction is finished (the reaction pressure is unchanged), removing unreacted ethylene oxide, cooling, neutralizing, decolorizing, filtering and dehydrating to obtain the alkyl polyoxyethylene polyoxypropylene ether with different polymerization degrees.

(3) And (3) adding the alkyl polyoxyethylene polyoxypropylene ether synthesized in the step (2) and triphenylphosphine (the molar ratio is 1:1.5) into a reaction kettle, dissolving the mixture in carbon tetrachloride of which the weight is 2-4 times that of the mixture, and reacting the mixture for 1-5 hours at the temperature of 25-80 ℃ to obtain the halide of the alkyl polyoxyethylene polyoxypropylene ether.

(4) Preparation of alkyl polyether quaternary ammonium salt

Will (R)₁R₂R₃) Dissolving N in a solvent, and adding potassium hydroxide to adjust the pH value to 9-10. Slowly adding the halogenated alkyl polyoxyethylene polyoxypropylene ether synthesized in the step (3) at the temperature of 60-80 ℃ according to the mol ratio of 1.1:1, and reacting for 10-16 hours. After the reaction is finished, the solvent is evaporated to obtain the product alkyl polyether quaternary ammonium salt. Wherein the solvent is selected from one of ethanol and isopropanol;

(5) and (3) uniformly mixing the aryl alcohol polyoxypropylene polyoxyethylene ether sulfonic acid product synthesized in the step (1), the alkyl polyether quaternary ammonium salt synthesized in the step (4), calculated amount of alkali liquor and water at a required ratio at 50-60 ℃ to obtain a surfactant product with required content.

[ example 2 ]

Aryl alcohol polyoxypropylene polyoxyethylene ether sodium sulfonate (R)₅＝CH₃(CH₂)₁₄，R₆＝CH₂，R₇＝CH₂，R₈＝C₉H₁₈M-9, n-6 and tetradecylpolyoxypropylene polyoxyethylene hydroxyethylammonium chloride (R)₁＝C₁₄H₃₀，R₂＝CH₃，R₃＝CH₃，R₄＝CH(OH)CH₃Respectively dissolving the a-2 and b-6) surfactants in formation water with the mineralization degree of 200000mg/L, stirring for 30 minutes to prepare 0.1-0.5% wt aqueous solution, and then mixing according to the molar ratio of the anions to the cationic surfactants of 1: 0.2 mixing the above surfactants uniformly to obtain the surfactant composition product solution 1 a.

[ example 3 ]

Aryl alcohol polyoxypropylene polyoxyethylene ether sodium sulfonate (R)₅＝CH₃(CH₂)₇，R₆＝C₅H₁₀，R₇＝C₂H₄，R₈＝C₆H₁₂M 7, n 5 and dodecyl polyoxypropylene polyoxyethylene ether hydroxyethyl ammonium chloride (R)₁＝C₁₂H₂₆，R₂＝CH₃，R₃＝CH₃，R₄＝CH(OH)CH₃Respectively dissolving a ═ 0 and b ═ 7) surfactants in formation water with the mineralization degree of 200000mg/L, stirring for 30 minutes to prepare 0.1-0.5% wt aqueous solution, and then mixing according to the molar ratio of anions to cationic surfactants of 1: 0.54 the above surfactants were mixed well to obtain a surfactant composition product solution 2 a.

[ example 4 ]

Aryl alcohol polyoxypropylene polyoxyethylene ether sodium sulfonate (R)₅＝CH₃(CH₂)₄，R₆＝C₅H₁₀，R₇＝C₅H₁₀，R₈＝C₄H₈M ═ 6, n ═ 2) and cetylpolyoxypropylene polyoxyethylene ether hydroxyethylammonium chloride (R)₁＝C₁₆H₃₄，R₂＝CH₃，R₃＝CH₃，R₄＝CH(OH)CH₃Respectively dissolving the a-3 and b-5) surfactants in formation water with the mineralization degree of 200000mg/L, stirring for 30 minutes to prepare 0.1-0.5% wt aqueous solution, and then mixing according to the molar ratio of the anions to the cationic surfactants of 1: 0.8 mixing the above surfactants uniformly to obtain the surfactant composition product solution 3 a.

[ example 5 ]

Aryl alcohol polyoxypropylene polyoxyethylene ether sodium sulfonate (R)₅＝COONa，R₆＝C₃H₆，R₇＝C₁₀H₂₀，R₈＝CH₂M-9, n-10 and octadecyl polyoxypropylene polyoxyethylene ether hydroxyethyl ammonium chloride (R)₁＝C₁₈H₃₈，R₂＝CH₃，R₃＝CH₃，R₄＝CH(OH)CH₃Respectively dissolving a ═ 0 and b ═ 5) surfactants in formation water with the mineralization degree of 200000mg/L, stirring for 30 minutes to prepare 0.1-0.5% wt aqueous solution, and then mixing according to the molar ratio of anions to cationic surfactants of 1: 0.6 mixing the above surfactants uniformly to obtain the surfactant composition product solution 4 a.

[ example 6 ]

Aryl alcohol polyoxypropylene polyoxyethylene ether sodium sulfonate (R)₅＝CH₃，R₆＝C₄H₈，R₇＝C₉H₁₈，R₈CH2, m 10, n 6 and dodecyl polyoxypropyleneth hydroxyethyl ammonium chloride (R)₁＝C₁₂H₂₆，R₂＝CH₃，R₃＝CH₃，R₄＝CH(OH)CH₃Respectively dissolving a ═ 0 and b ═ 7) surfactants in formation water with the mineralization degree of 200000mg/L, stirring for 30 minutes to prepare 0.1-0.5% wt aqueous solution, and then mixing according to the molar ratio of anions to cationic surfactants of 1: 0.9 mixing the above surfactants uniformly to obtain the surfactant composition product solution 5 a.

[ example 7 ]

Aryl alcohol polyoxypropylene polyoxyethylene ether sodium sulfonate (R)₅＝SO₃Na，R₆＝CH₂，R₇＝C₃H₆，R₈＝C₃H₆M is 6, n is 6 and octadecyl polyoxypropylene polyoxyethylene ether ammonium chloride (R)₁＝C₁₈H₃₈，R₂＝CH₃，R₃＝CH₃，R₄＝CH₂CH₃，a＝0，b＝5)Respectively dissolving the surfactant in formation water with the mineralization of 200000mg/L, stirring for 30 minutes to prepare 0.1-0.5% wt aqueous solution, and then mixing according to the following anion: cationic surfactant molar ratio 1: 1.9 mixing the above surfactants uniformly to obtain the surfactant composition product solution 6 a.

[ example 8 ]

Aryl alcohol polyoxypropylene polyoxyethylene ether sodium carboxylate (R)₅＝CH₃(CH₂)₄，R₆＝CH₂，R₇＝C₅H₁₀，R₈＝C₄H₈M 4, n 5 and dodecyl poly-oxypropylene polyoxyethylene hydroxyethyl ammonium chloride (R)₁＝C₁₂H₂₆，R₂＝CH₃，R₃＝CH₃，R₄＝CH(OH)CH₃A is 0, b is 7) surfactant is respectively dissolved in formation water with the mineralization of 200000mg/L, stirred for 30 minutes to prepare 0.1-0.5% wt aqueous solution, and then according to the anion: cationic surfactant molar ratio 1: 2.2 mixing the surface active agents evenly to obtain a surface active agent composition product solution 7 a.

[ example 9 ]

Aryl alcohol polyoxypropylene polyoxyethylene ether sodium carboxylate (R)₅＝SO₃Na，R₆＝C₂H₄，R₇＝CH₂，R₈＝CH₂M is 5, n is 7 and octadecyl polyoxypropylene polyoxyethylene ether ammonium chloride (R)₁＝C₁₈H₃₈，R₂＝CH₃，R₃＝CH₃，R₄＝CH₂CH₃Respectively dissolving a ═ 0 and b ═ 5) surfactants in formation water with the mineralization degree of 200000mg/L, stirring for 30 minutes to prepare 0.1-0.5% wt aqueous solution, and then mixing according to the anion: cationic surfactant molar ratio 1: 0.2 mixing the above surfactants uniformly to obtain the surfactant composition product solution 8 a.

[ example 10 ]

Aryl alcohol polyoxypropylene polyoxyethylene ether sodium carboxylate (R)₅＝CH₃(CH₂)₇，R₆＝C₅H₁₀，R₇＝C₂H₄，R₈＝C₆H₁₂M 4, n 7 and hexadecyl polyoxy propylene polyoxyethylene ether hydroxyethyl ammonium chloride (R)₁＝C₁₆H₃₄，R₂＝CH₃，R₃＝CH₃，R₄＝CH(OH)CH₃A is 3, b is 5) surfactant is respectively dissolved in formation water with the mineralization of 200000mg/L, stirred for 30 minutes to prepare 0.1-0.5% wt aqueous solution, and then according to the anion: cationic surfactant molar ratio 1: 0.5 mixing the above surfactants uniformly to obtain the surfactant composition product solution 9 a.

[ example 11a ] interfacial Property test of surfactant composition

The oil-water interfacial tension of the surfactant composition solution of examples 2-10 and Jianghan crude oil was measured by a TX-500C spinning drop interfacial tensiometer, and the test results are shown in Table 1:

and (3) testing temperature: 85 ℃; the mineralization degree of the formation water is 20000 mg/L.

TABLE 1 oil-water interfacial tension of composite surfactant compositions

[ example 11b ] ultra-low interfacial tension window test for surfactant compositions

The surfactant composition described in example 3 was selected, samples of different concentrations of surfactant were prepared with formation water, and oil-water interfacial tension concentration window tests were performed at 85 ℃ (heated by an external oil bath) using a TX-500C spinning drop interfacial tensiometer (rotating speed 4500 rpm), the results of which are shown in table 2.

TABLE 2 oil-water interfacial tension of different concentrations of surfactant

Concentration wt%	0.010	0.025	0.05	0.1	0.3	0.5
							Interfacial tension mN/m	0.0065	0.0039	0.0025	0.0022	0.0020	0.0024

The results show that the surfactant composition has high oil-water interfacial activity on crude oil in Jianghan oil field

[ example 12 ] oil-washing ability test of surfactant composition

The method comprises the steps of cleaning stratum sand of the Jianghan oil field, grinding and sieving for later use, uniformly mixing the stratum sand with target crude oil according to the saturation of residual oil, aging the mixture for 7 days at the oil reservoir temperature, taking out 5 g of aged oil sand, and then performing oil sand treatment according to the following steps: and (3) adding 0.5% of surfactant composition solution into the solution in a ratio of 1:10, uniformly mixing, standing at the oil reservoir temperature for 72 hours, separating the oil sand from the oil-containing surfactant solution, and measuring the residual oil in the oil sand by a thermogravimetric method to calculate the oil washing capacity.

TABLE 3 oil wash results for surfactant compositions

Examples	Oil washing rate%
		2	53.3
3	71.4
		4	65.4
5	75.2
		6	60.0
7	51.7
		8	63.9
9	55.5
		10	66.8

[ COMPARATIVE EXAMPLE 1 ]

According to the method of patent CN109652048A, symmetric alkyl alcohol polyoxyethylene ether sulfonate anionic-nonionic surfactant and cetyl trimethyl ammonium bromide surfactant are respectively dissolved in formation water to prepare 0.1 wt% aqueous solution, and the molar ratio of anionic surfactant to nonionic surfactant to cationic surfactant is 0.25. And stirred for 30 minutes to mix well to give reference surfactant composition 1 b.

[ COMPARATIVE EXAMPLE 2 ]

Aryl alcohol polyoxypropylene polyoxyethylene ether sodium sulfonate (R)₅＝CH₃(CH₂)₇，R₆＝C₅H₁₀，R₇＝C₂H₄，R₈＝C₆H₁₂M-7, n-5) surfactant and cetyltrimethylammonium chloride surfactant are respectively dissolved in formation water with the mineralization degree of 200000mg/L, stirred for 30 minutes to prepare 0.1% wt aqueous solution, and then the weight ratio of the surfactant to the surfactant is determined according to the following formula: cationic surfactant molar ratio 1: 0.54 the above surfactants were mixed well to obtain a surfactant composition product solution 2 b.

[ COMPARATIVE EXAMPLE 3 ]

Aryl alcohol polyoxypropylene polyoxyethylene ether sodium sulfonate (R)₅＝CH₃(CH₂)₇，R₆＝C₅H₁₀，R₇＝C₂H₄，R₈＝C₆H₁₂M-7 and n-5) were dissolved in formation water having a degree of mineralization of 200000mg/L, and stirred for 30 minutes to prepare a 0.1% wt aqueous solution, thereby obtaining a reference surfactant solution 3 b.

Comparative example 4 interfacial Property test for different surfactant compositions

The oil-water interfacial tension of the surfactant composition solution of examples 2-10 and Jianghan crude oil was measured using a TX-500C spinning drop interfacial tensiometer, and the test results are shown in Table 4:

TABLE 4 surfactant composition oil-water interfacial tension

Sample (I)	Interfacial tension (mN/m)
		Example 3	0.0022
Comparative example 1b	0.033
		Comparative example 2b	0.026
Comparative example 3b	0.057

As shown in table 4, example 3 has a more significant property of reducing the interfacial tension between oil and water than the comparative examples, and the anionic and cationic surfactants have a higher interfacial performance after being compounded than the single surfactant.

Claims

1. The composite surfactant comprises the following components in parts by weight:

(1) 0.01-1.0 part of alkyl polyether quaternary ammonium salt surfactant;

(2) 0.02-1.0 part of aryl alcohol polyether acid salt surfactant;

2. The composite surfactant according to claim 1, wherein R is₁Is C₁～C₂₀Alkyl groups of (a); said R₂、R₃、R₄Independently selected as C₁、C₂、C₃Alkyl or hydroxy-substituted alkyl.

3. The enhanced oil recovery composite surfactant of claim 1, wherein R is₅Is C₁～C₂₀Alkyl, aryl, SO₃M or COON; r₆Is C₁、C₂Or C₃An alkylene group of (a); r₇、R₈Independently selected as C₂、C₃Or C₄An alkylene group of (a).

4. The composite surfactant according to claim 1, wherein a is 0 to 5 and b is 5 to 8.

5. The composite surfactant according to claim 1, wherein m is 0 to 10 and n is 2 to 10.

6. The composite surfactant according to claim 1, wherein the mass ratio of the aryl alcohol polyether acid salt surfactant to the alkyl polyether quaternary ammonium salt surfactant is 25-1, preferably 15-1, more preferably 8-1, and most preferably 2.5-1.

7. The composite surfactant according to claim 1, characterized by further comprising 98.0-99.98 parts by mass of injection water.

8. A method for preparing the composite surfactant as claimed in any one of claims 1 to 7, comprising the steps of:

(a) preparation of aryl alcohol polyether acid salt

HO- [ CH (CH)₃)CH₂O]-[CH₂CH₂O]-R₆Y and

reacting at 100-180 ℃ in the presence of a catalyst, then adding water for dilution, carrying out oil-water separation, and obtaining aryl alcohol polyether acid salt in a water phase; wherein, the HO- [ CH (CH)₃)CH₂O]-[CH₂CH₂O]-R₆Y and

the molar ratio is preferably 1 (2-5), the catalyst is preferably an alkaline catalyst, and more preferably an alkali metal hydroxide;

(b) preparation of alkyl polyoxyethylene polyoxypropylene ether

R is to be₄Performing alkoxylation reaction on OH and required amount of propylene oxide and ethylene oxide in the presence of basic catalyst to obtain the alkyl polyoxyethylene polyoxypropylene ether, wherein the amount of the basic catalyst is preferably R₄1-3 wt% of OH; said alkoxylation reactionThe reaction conditions are preferably: the reaction temperature is preferably 100-180 ℃, and the reaction pressure is preferably less than 0.60MPa gauge pressure;

(c) halogenation of alkylpolyoxyethylene polyoxypropylene ethers

Mixing the alkyl polyoxyethylene polyoxypropylene ether synthesized in the step (c) with a halogenating reagent, and carrying out halogenation reaction to obtain halogenated alkyl polyoxyethylene polyoxypropylene ether; wherein the preferable temperature of the halogenation reaction is 25-80 ℃;

(d) preparation of alkyl polyether quaternary ammonium salt

Will (R)₁R₂R₃) N and the halogenated alkyl polyoxyethylene polyoxypropylene ether synthesized in the step (c) are subjected to quaternization reaction; after the reaction is finished, evaporating the solvent to obtain the product alkyl polyether quaternary ammonium salt; wherein, the solvent is preferably selected from at least one of ethanol and isopropanol; the quaternization reaction is preferably carried out in a solvent, and the pH value of the reaction is 9-10; the reaction temperature is preferably 60-80 ℃, and the reaction time is preferably 10-16 hours; said (R)₁R₂R₃) The mol ratio of N to halogenated alkyl polyoxyethylene polyoxypropylene ether halide is preferably (1-1.2): 1;

(e) mixing the aryl alcohol polyether acid salt synthesized in the step (a), the alkyl polyether quaternary ammonium salt synthesized in the step (d) and injected water according to the required proportion, stirring, and adjusting the pH value to 7-10 to obtain the required composite surfactant; the pH value is more preferably 8 to 9.5.

9. Use of the enhanced oil recovery composite surfactant according to any one of claims 1 to 8 in oil recovery in an oil field.

10. Use of the surfactant composition according to claim 9 for enhanced oil recovery, characterized in that the surfactant composition is injected in the form of an aqueous solution into the reservoir formation in contact with the crude oil and displaces the crude oil.