CN106590598B

CN106590598B - Oil displacement composition and preparation method thereof

Info

Publication number: CN106590598B
Application number: CN201510683875.0A
Authority: CN
Inventors: 沈之芹; 李应成; 王辉辉; 吴国英
Original assignee: Sinopec Shanghai Research Institute of Petrochemical Technology; China Petrochemical Corp
Current assignee: Sinopec Shanghai Research Institute of Petrochemical Technology; China Petrochemical Corp
Priority date: 2015-10-20
Filing date: 2015-10-20
Publication date: 2019-12-10
Anticipated expiration: 2035-10-20
Also published as: CN106590598A

Abstract

The invention relates to an oil displacement composition and a preparation method thereof, which mainly solve the problem of poor oil displacement efficiency of the oil displacement composition in the prior art, the oil displacement composition comprises the following components, by mass, 1)1 part of surfactant, 2) 0-50 parts and more than 0 part of polymer, wherein the surfactant is a mixture containing a nonionic surfactant shown in a formula (1) and anionic surfactants shown in formulas (2) and (3) in a mass ratio of (0.01-5) to 1 (0.1-5), wherein R ₁, R ₂ and R ₃ are C ₄ -C ₄₀ aliphatic hydrocarbon or C ₄ -C ₃₀ straight chain or branched chain saturated and unsaturated hydrocarbon substituted aryl, and the technical scheme better solves the problem, can be used in oil displacement composition of oil fields and enhanced oil recovery production, and

Description

Oil displacement composition and preparation method thereof

Technical Field

The invention relates to an oil displacement composition and a preparation method thereof.

Background

The enhanced oil recovery technology, namely the Enhanced Oil Recovery (EOR) and Improved Oil Recovery (IOR) technology generally referred to abroad, can be summarized into six aspects of improving water flooding, chemical flooding, heavy oil thermal recovery, gas flooding, microbial oil recovery, physical oil recovery and the like. Currently, the enhanced oil recovery techniques that enter large-scale applications in mines are focused on the three major categories of thermal recovery, gas flooding and chemical flooding, with chemical flooding yields of 5.18 x 10⁴m³Over/d, accounting for about 14.7% of the total EOR production in the world. Chemical flooding is a strengthening measure for improving the recovery rate by adding a chemical agent into an aqueous solution and changing the physicochemical property and rheological property of an injected fluid and the interaction characteristic with reservoir rocks, and is rapidly developed in China, mainly because the reservoir deposits in China have strong heterogeneity, the viscosity of the continental-phase crude oil is high, and the method is more suitable for chemical flooding in an EOR method.

The surfactant oil displacement technology is a method for improving the oil displacement efficiency by adding a surfactant into injected water and reducing the oil-water interfacial tension to improve the oil washing capacity. Compared with general water flooding, the polymer flooding mainly increases the viscosity of a water phase, controls the fluidity ratio of a flooding system, plays a role in enlarging swept volume, and has lower cost compared with a surfactant. The addition of the alkali mainly reduces the adsorption quantity of the surfactant and increases the interfacial activity of the surfactant. As an important technology in chemical flooding, surfactant active water flooding, micellar solution flooding and microemulsion flooding technologies, polymer surfactant formed binary composite flooding technologies and polymer surfactant alkali formed ternary composite flooding technologies have been subjected to some mine field tests at home and abroad, and good flooding effects are obtained. In 2002, the Daqing oil field develops an active water injection pressure reduction and injection increase test in a peripheral low-permeability oil field, and in 2003, develops an active water injection oil displacement test in a peripheral low-permeability oil field and a reservoir outside the surface of a loudspeaker, a pizza and an apricot oil field, and aims to greatly reduce the oil-water interfacial tension, reduce the action of interphase surfaces, activate and disperse retained oil blocks or strip adhered oil films, improve the flow permeability of an oil layer by means of the increase of the flow porosity, and achieve the effects of reducing the starting pressure, improving the water injection wave and volume and improving the oil displacement efficiency. Practice proves that the active water flooding can greatly improve the recovery ratio of crude oil in a development block, and effectively develop part of reserves which cannot be used under the current economic and technical conditions. Since 1994, Daqing oil field adopts the heavy alkylbenzene sulfonate imported from abroad to carry out 5 ternary combination flooding tests, and the crude oil recovery rate is increased by 20% on the basis of the water flooding recovery rate, thereby defining the dominant tertiary oil recovery technology after the ternary combination flooding is polymer flooding. After the ternary combination flooding pilot field test of the oil field succeeds, the problems of scaling and difficult demulsification are considered, a technical route of binary combination flooding is adopted, petroleum sulfonate surfactant synthesized by using victory crude oil as a raw material is used as a main agent, nonionic surface activity is used as an auxiliary agent, ultralow interfacial tension can be achieved under the alkali-free condition, a pilot test of the mine field is carried out in southwest of the seven regions of eastern soliton in 2003, the recovery ratio is improved by 12%, and the problems of scaling and difficult demulsification are solved.

In the oil displacement technology implemented above, the use of the high-activity surfactant is one of the key factors, but the surfactant suitable for oil displacement in China is few in types, poor in product performance stability and not strong in universality. The screening of the surfactant for oil displacement in China is mainly based on the capability of reducing the oil-water interfacial tension, and the selection of the surfactant for oil displacement and the cosurfactant in foreign countries is based on the phase behavior of an oil displacement system and crude oil: (1) forming large middle-phase micro-emulsion; (2) high solubilization parameters at optimal salinity; (3) no viscous phase such as lamellar liquid crystal, etc. can be produced. In 1973, Healy and Reed firstly studied the microemulsion system by using a three-phase diagram, and then through the work of Healy, Reed, Nelson, Pope and Huh, the correlation between the oil displacement efficiency and the phase characteristics, and the correlation between the solubilization parameters and the interfacial tension are established. Although the phase behavior is based on the research of concentrated surfactant flooding such as microemulsion flooding, the theoretical system is complete, so the screening of the foreign high-efficiency surfactant oil flooding system is still based on the theoretical system.

The surfactant used in tertiary oil recovery studies is most anionic in type, followed by nonionic and zwitterionic, and least cationic in type. The results of oil displacement by using alkaline water, surfactant or alkaline water oil displacement and oil displacement by using zwitterionic surfactant are sequentially reported by US3927716, US4018281 and US4216097 of Mofu Petroleum company, the zwitterionic surfactant is carboxylic acid or sulfonate type betaine surfactant with different chain lengths, and the interfacial tension on crude oil in Texas south Texas is 10 in simulated saline with total mineralization of 62000-160000 mg/L and calcium and magnesium ions of 1500-18000 mg/L^-1～10^-4mN/m. Patent US4370243 of Mobil Petroleum company reports an oil displacement system composed of oil-soluble alcohol, betaine sulfonate and quaternary ammonium salt, wherein the system can play a role of a surfactant and a fluidity control agent, the quaternary ammonium salt is a cationic surfactant with a lipophilic carbon chain length of 16-20, and 2 wt% of octadecyl dihydroxyethyl propyl betaine sulfonate and 1.0% of n-hexanol are adoptedAs a displacement composition, after 1.9PV is injected, 100 percent of crude oil can be expelled, but the adsorption loss of the surfactant is larger and reaches 6mg/g, and on the basis, 2.0 percent tetraethylammonium bromide with relatively low price is added as a sacrificial agent to reduce the adsorption quantity of the surfactant. U.S. Pat. No. 2,8211837, the university of Texas, USA, reports that linear alcohol with low cost is adopted to catalyze dimerization reaction at high temperature to obtain branched long carbon alcohol, and then sulfuric acid esterification reaction is carried out after polymerization with propylene oxide and ethylene oxide, compared with expensive sulfonate type surfactant, large hydrophilic group polyether sulfate surfactant is synthesized at low cost, due to existence of large hydrophilic group, the sulfate surfactant has excellent high-temperature stability under alkaline condition, and 0.3% branched alcohol polyether sulfate (C-alcohol polyether sulfate) is used₃₂-7PO-6EO sulfate) with 0.3% of an internal olefin sulfonate (C)_20～24IOS) brine solution was mixed with the same amount of crude oil at 85 ℃ with a solubilization parameter of 14. The surfactant used in foreign research is limited in practical application as an oil displacement composition due to large usage amount and high cost. For example, chinese patents CN 1528853, CN1817431 and CN 1066137 sequentially report bisamide type cationic, fluorine-containing cationic and pyridyl-containing cationic gemini surfactants, but the use of cations in oil field sites is limited due to the disadvantages of large adsorption loss, high cost and the like.

In the oil displacement technology implemented above, the use of temperature-resistant and salt-resistant polymers is another key factor. Early commercial products of polymer flooding, commonly used for Enhanced Oil Recovery (EOR), were only partially Hydrolyzed Polyacrylamides (HPAMs), which relied on the exclusion of high molecular weight and ionic and strongly polar side groups on the polymer molecular chain to achieve viscosifying effects. However, high molecular weight polymers are susceptible to mechanical degradation and loss of viscosity when subjected to high tensile and shear stresses, particularly when injected into low permeability formations. Cations, especially divalent ions, in the aqueous solution can shield ionic groups in the polymer, so that polymer molecular chains are curled, the hydrodynamic volume is reduced, even the polymer is precipitated, and the tackifying property is greatly reduced. When the temperature of a stratum oil layer is higher (more than 93 ℃), amide groups in Polyacrylamide (PAM) are easy to hydrolyze in a high-temperature aqueous solution, so that the salt resistance of a polymer solution is reduced rapidly. In recent years, the research on temperature and salt resistant polyacrylamide mainly improves the thermal stability of the polymer by introducing large side groups or rigid side groups to the main chain of the polymer, improves the hydrolysis resistance and salt resistance of the polymer by introducing monomers inhibiting hydrolysis or copolymerizing monomers insensitive to salt, or improves the temperature and salt resistance of the polymer by hydrophobic association of hydrophobic groups.

The chemical oil displacement technology in China is advanced, the field matching process is complete, and the development of the chemical oil displacement technology in the application research and development of medium-high permeability oil reservoirs is of great significance. Therefore, aiming at the sandstone reservoir with high temperature and high salt, the invention provides the sandstone reservoir which has stable structure at the formation temperature and can form 10 with crude oil^-2～10^-4An oil displacement composition system with mN/m low interfacial tension and effectively improved crude oil recovery efficiency. The invention relates to a preparation method of the oil displacement composition and application thereof in enhanced oil recovery.

Disclosure of Invention

One of the technical problems to be solved by the invention is the problem of poor oil displacement efficiency of the oil displacement composition in the prior art, and the invention provides a novel oil displacement composition. The oil displacement composition takes an aqueous solution containing a surfactant or an aqueous solution of the surfactant and a polymer as the oil displacement composition for the oil displacement process, and has the advantages of good temperature resistance and salt resistance and high oil displacement efficiency under the harsh conditions of high temperature and ultrahigh salt.

The second technical problem to be solved by the invention is to provide a preparation method of the oil-displacing composition for solving the first technical problem.

In order to solve one of the above technical problems, the technical solution adopted by the present invention is as follows: the oil displacement composition comprises the following components in parts by weight:

1)1 part of a surfactant;

2)0 to 50 parts and more than 0 part of a polymer;

The surfactant is an anionic nonionic mixed surfactant and comprises a nonionic surfactant shown in a formula (1), an anionic surfactant shown in a formula (2) and an anionic surfactant shown in a formula (3), wherein the mass ratio of the nonionic surfactant shown in the formula (1), the anionic surfactant shown in the formula (2) and the anionic surfactant shown in the formula (3) is (0.01-5): 1: (0.1-5);

R₁And R₂And R₃Are all independently selected from C₄～C₄₀Aliphatic hydrocarbon radical of or consisting of C₄～C₃₀Linear or branched, saturated and unsaturated hydrocarbyl-substituted aryl groups; m1, m2, m3 and m4 are independently selected from 0-50, but m1 and m2, and m3 and m4 cannot be 0 at the same time; n1 and n2 are independently selected from 0-100, but n1 and n2 cannot be 0 at the same time; r1, r2, r3 and r4 are independently selected from 0-50, but r1 and r2, and r3 and r4 cannot be 0 at the same time; s1 and s2 are independently selected from 0-100, but s1 and s2 cannot be 0 at the same time; p1, p2, p3 and p4 are independently selected from 0-50, but p1 and p2, and p3 and p4 cannot be 0 at the same time; q1 and q2 are independently selected from 0-100, but q1 and q2 cannot be 0 at the same time; z₁And Z₂And Z₃Are each-R₀₁Y₁、－R₀₂Y₂、－R₀₃Y₃；R₀₁And R₀₂And R₀₃Is selected from C₁～C₅Alkylene or hydroxy-substituted alkylene of, Y₁And Y₂And Y₃Selected from SO₃M or COOW, M and W being independently selected from hydrogen, alkali metal or of formula NR₄(R₅)(R₆)(R₇) A group shown, R₄、R₅、R₆、R₇Is independently selected from H, (CH)₂)_pOH or (CH)₂)_q CH₃P is any integer of 2 to 4, and q is any integer of 0 to 5.

In the above technical means, the mass ratio of the nonionic surfactant represented by the formula (1), the anionic surfactant represented by the formula (2), and the anionic surfactant represented by the formula (3) is preferably (0.03 to 3): 1: (1-3).

The above techniquein scheme (I), the R is preferably₁or R₂Or R₃At least one of them is C₆～C₂₀Or from C₈～C₁₆Alkyl-substituted phenyl.

In the above-described embodiment, p is preferably 2 and q is preferably 0 to 1.

In the technical scheme, preferably, m1+ m2 is 2-10, m3+ m4 is 2-20, and n1+ n2 is 5-40; and/or r1+ r2 is 2-10, r3+ r4 is 2-20, s1+ s2 is 5-40 and/or p1+ p2 is 2-10, p3+ p4 is 2-20, and q1+ q2 is 5-40.

The key of the anionic nonionic mixed oil-displacing surfactant is that the effective components are a nonionic surfactant shown in a formula (1), an anionic surfactant shown in a formula (2) and an anionic surfactant shown in a formula (3), wherein the formula (2) shows a single hydrophilic head group anionic surfactant, and the formula (3) shows a double hydrophilic head group anionic surfactant; those skilled in the art will appreciate that various forms of supply, such as non-aqueous solid form, or aqueous paste form, or aqueous solution form, may be used for convenience of transportation and storage or for on-site use; the aqueous solution form comprises a form of preparing a concentrated solution by water, and is directly prepared into a solution form with the concentration required by the on-site oil displacement, for example, a solution with the key active ingredient content of 0.005-0.6 wt% by mass is a form suitable for the on-site oil displacement; the water is not particularly required, and can be deionized water or water containing inorganic mineral substances, and the water containing the inorganic mineral substances can be tap water, oil field formation water or oil field injection water.

The anionic and non-mixed oil-displacing surfactant can be obtained by mixing the nonionic surfactant, the single hydrophilic head-based anionic surfactant and the double hydrophilic head-based anionic surfactant according to a required proportion, and is preferably obtained by one or two of the following technical schemes for solving the two technical problems.

In the above technical solution, the polymer is not strictly limited, and may be various polymers for oil field oil recovery known to those skilled in the art, and those skilled in the art can select the polymer according to the prior art, for example, but not limited to, at least one selected from xanthan gum, hydroxymethyl cellulose, hydroxyethyl cellulose, anionic polyacrylamide, modified polyacrylamide, hydrophobically associating polymer, and polymer microsphere.

In the above technical solution, the modified polyacrylamide and the hydrophobic association polymer are preferably copolymerized by acrylamide, temperature-resistant and salt-resistant monomer or hydrophobic monomer, and the temperature-resistant and salt-resistant monomer or hydrophobic monomer may be at least one of monomers containing large side groups or rigid side groups (such as styrenesulfonic acid, N-alkylmaleimide, acrylamido long-chain alkylsulfonic acid, long-chain alkylallyl dimethyl ammonium halide, 3-acrylamido-3-methylbutyric acid, etc.), monomers containing salt-resistant groups (such as 2-acrylamido-2-methylpropanesulfonic acid), monomers containing hydrolysis-resistant groups (such as N-alkylacrylamide), monomers containing groups capable of inhibiting amide hydrolysis (such as N-vinylpyrrolidone), monomers containing hydrophobic groups, etc. known to those skilled in the art, the temperature-resistant and salt-resistant monomer is preferably 2-acrylamido-2-methylpropanesulfonic acid, and the hydrophobic monomer is preferably 2-acrylamidododecyl sulfonic acid.

in the technical scheme, the mol ratio of acrylamide to the temperature-resistant salt-resistant monomer in the modified polyacrylamide is preferably (0.1-40) to 1, and more preferably (0.1-20) to 1; the molar ratio of acrylamide to the temperature-resistant salt-resistant monomer to the hydrophobic monomer in the hydrophobic association polymer is 1: (0.1-40): (0.001 to 0.05), more preferably 1: (0.1 to 20): (0.001 to 0.01).

In the technical scheme, the modified polyacrylamide is preferably prepared by copolymerizing acrylamide and 2-acrylamide-2-methylpropanesulfonic acid, and the molar ratio of the acrylamide to the 2-acrylamide-2-methylpropanesulfonic acid is preferably (0.1-40) to 1, and more preferably (0.1-20) to 1; the hydrophobic association polymer is preferably formed by copolymerizing acrylamide, 2-acrylamido-2-methylpropanesulfonic acid and 2-acrylamidododecyl sulfonic acid, wherein the molar ratio of the acrylamide to the 2-acrylamido-2-methylpropanesulfonic acid to the 2-acrylamidododecyl sulfonic acid is preferably 1: (0.1-40): (0.001 to 0.05), more preferably 1: (0.1 to 20): (0.001 to 0.01).

In the technical scheme, the viscosity average molecular weight of the modified polyacrylamide is preferably 800-2500 ten thousand, more preferably 1000-2000 ten thousand, and the viscosity average molecular weight of the hydrophobically associating polymer is preferably 1000-2500 ten thousand, more preferably 1200-2200 ten thousand.

In the technical scheme, the mass ratio of the surfactant to the polymer in the oil displacing composition is preferably 1 to (0-2).

To solve the second technical problem, one of the technical solutions adopted by the present invention is as follows: the preparation method of the oil displacement composition in one of the technical problems comprises the following steps:

a. In the presence of a basic catalyst, R₁NH₂Sequentially reacting with required amount of ethylene oxide, propylene oxide and ethylene oxide to obtain R₁N((CH₂CH₂O)_m1(CHCH₃CH₂O)_n1(CH₂CH₂O)_m3H)((CH₂CH₂O)_m2)(CHCH₃CH₂O)_n2(CH₂CH₂O)_m4H)；

b. B, mixing the product obtained in the step a with X₁R₀₁Y₀₁And reacting alkali metal hydroxide or alkali metal alkoxide in a solvent according to a molar ratio of 1 (1-2) to (1-4) at a reaction temperature of 50-120 ℃ for 3-15 hours to obtain a mixture containing a nonionic surfactant shown in a formula (1), the mono-hydrophilic head-based anionic surfactant shown in the formula (4) and the bi-hydrophilic head-based anionic surfactant shown in the formula (5);

Wherein Z is₀₁is-R₀₂Y₀₁；Y₀₁Selected from SO₃M₁or COOW₁，M₁And W₁Is an alkali metal, X₁selected from chlorine, bromine or iodine.

c. And c, uniformly mixing the surfactant mixture obtained in the step b with the polymer in parts by mass to obtain the oil displacing composition.

In the above technical solution, R in step b₁N((CH₂CH₂O)_m1(CHCH₃CH₂O)_n1(CH₂CH₂O)_m3H)((CH₂CH₂O)_m2)(CHCH₃CH₂O)_n2(CH₂CH₂O)_m4H):X₁R₀₁Y₀₁The molar ratio of the alkali metal hydroxide or alkali metal alkoxide is preferably 1 (1-2) to 1-3.

in the above technical scheme, the solvent in the step b is preferably selected from C₃～C₈Ketone and C₆～C₉For example, at least one of the group consisting of acetone, butanone, pentanone, benzene, toluene or xylene, trimethylbenzene, ethylbenzene and diethylbenzene.

In the above technical scheme, the alkaline catalyst can be selected from alkali metal hydroxide (such as sodium hydroxide or potassium hydroxide) and alkali metal alkoxide (such as sodium methoxide, potassium methoxide, sodium ethoxide and potassium ethoxide).

As long as the reaction of the step b is carried out, a person skilled in the art can obtain the anionic-nonionic mixed oil-displacing surfactant containing the salt and the excessive basic catalyst by only removing the solvent by distillation without complicated separation. Step b can be carried out without inventive work by a person skilled in the art in order to obtain a product comprising formula (1) and formula (4) and formula (5) free of salts and excess basic catalyst.

For example, in order to obtain an anionic-nonionic surfactant and a nonionic surfactant of the formula (1), a mono-hydrophilic head-based anionic surfactant of the formula (4) and a bis-hydrophilic head-based anionic surfactant of the formula (6) without salts and an excess amount of an alkali catalyst, when M is M, a surfactant of a non-mixed type is used as a flooding surfactant₁Or W₁The product of H can further comprise a step d and a step e:

d. B, adding an acid into the reaction mixture obtained in the step b to adjust the pH value of the water phase to be 1-3, and separating to obtain an organic phase;

e. The resulting organic phase is concentrated to give the desired product.

As another example, an anionic non-mixed type oil-displacing surfactant comprising a nonionic surfactant represented by the formula (1), a mono-hydrophilic head-based anionic surfactant represented by the formula (4) and an bis-hydrophilic head-based anionic surfactant represented by the formula (6) in order to obtain a salt-free and excess amount of the basic catalyst when M is M₁Or W₁is an alkali metal or of the formula NR₄(R₅)(R₆)(R₇) The products of the radicals indicated can be used in step d with the desired alkali metals or of the formula NR₄(R₅)(R₆)(R₇) Neutralizing with alkali corresponding to the group, and removing the solvent from the organic phase.

Alkali metals or compounds of formula NR as described in the above schemes₄(R₅)(R₆)(R₇) Bases corresponding to the groups shown, e.g. bases corresponding to alkali metals selected from alkali metal hydroxides, alkali metal carbonates, alkali metal bicarbonates, alkali metal oxides or alkali metal alkoxides, etc., with NR₄(R₅)(R₆)(R₇) The corresponding alkali of the group is selected from ammonia, ethanolamine, diethanolamine, triethanolamine, triethylamine, quaternary ammonium base and the like.

X₁R₀₁Y₀₁examples of (d) include, but are not limited to, alkali metal salts of chloroacetic acid (e.g., sodium chloroacetate), alkali metal salts of 3-chloro-2-hydroxypropanesulfonic acid, alkali metal salts of 2-chloroethanesulfonic acid, and the like.

In order to solve the second technical problem, the second technical solution of the present invention is as follows: one of the technical problems is that the preparation method of the oil displacement composition comprises the following steps:

(b) Reacting a product obtained in the step a of the technical scheme with 1, 3-propane sultone and alkali metal hydroxide or alkali metal alkoxide in a molar ratio of 1 (1-2) to (1-4) in a solvent at a reaction temperature of 50-120 ℃ for 3-15 hours to obtain a mixture containing a nonionic surfactant shown in a formula (1), a single hydrophilic head group anionic surfactant shown in a formula (6) and a double hydrophilic head group anionic surfactant shown in a formula (7);

Wherein Z'₀₁is-CH₂CH₂CH₂SO₃M₂；M₂Is an alkali metal.

(c) And (c) uniformly mixing the surfactant mixture obtained in the step (b) with the polymer in parts by mass to obtain the oil displacing composition.

In the above technical solution, R in step (b)₁N((CH₂CH₂O)_m1(CHCH₃CH₂O)_n1(CH₂CH₂O)_m3H)((CH₂CH₂O)_m2)(CHCH₃CH₂O)_n2(CH₂CH₂O)_m4H) The molar ratio of 1, 3-propanesultone to alkali metal hydroxide or alkali metal alkoxide is preferably 1 (1-2) to 1-4.

In the above technical solution, R in step b₁N((CH₂CH₂O)_m1(CHCH₃CH₂O)_n1(CH₂CH₂O)_m3H)((CH₂CH₂O)_m2)(CHCH₃CH₂O)_n2(CH₂CH₂O)_m4H) The molar ratio of 1, 3-propanesultone to alkali metal hydroxide or alkali metal alkoxide is preferably 1 (1-2) to 1-3.

In the above technical solution, the solvent in the step (b) is preferably selected from C₃～C₈Ketone and C₆～C₉For example, at least one of the group consisting of acetone, butanone, pentanone, benzene, toluene or xylene, trimethylbenzene, ethylbenzene and diethylbenzene.

As long as the reaction of the step (b) is carried out, a person skilled in the art can obtain the anionic-nonionic mixed oil-displacing surfactant containing the salt and the excessive alkaline catalyst by only removing the solvent by distillation without complicated separation. Step (b) can be carried out without inventive work by a person skilled in the art in order to obtain a product comprising formula (1) and formula (6) and formula (7) free of salts and excess basic catalyst.

For example, in order to obtain an anionic-nonionic surfactant and a nonionic surfactant of the formula (1), a mono-hydrophilic head-based anionic surfactant of the formula (6) and a bis-hydrophilic head-based anionic surfactant of the formula (7) without salts and an excess amount of an alkali catalyst, when M is M, a surfactant of a non-mixed type is used as a flooding surfactant₁Or W₁The product of H, further comprising step (d) and step (e):

(d) Adding an acid into the reaction mixture obtained in the step (b) to adjust the pH value of the water phase to 1-3, and separating to obtain an organic phase;

(e) The resulting organic phase is concentrated to give the desired product.

As another example, an anionic non-mixed type oil-displacing surfactant comprising a nonionic surfactant represented by the formula (1), a mono-hydrophilic head-based anionic surfactant represented by the formula (6) and an bis-hydrophilic head-based anionic surfactant represented by the formula (7) in order to obtain a salt-free and excess amount of the basic catalyst when M is M₁Or W₁Is an alkali metal or of the formula NR₄(R₅)(R₆)(R₇) The products of the indicated radicals can be used in step (d) with the desired alkali metals or compounds of the formula NR₄(R₅)(R₆)(R₇) Neutralizing with alkali corresponding to the group, and removing the solvent from the organic phase.

Alkali metals or compounds of formula NR as described in the above schemes₄(R₅)(R₆)(R₇) Bases corresponding to the radicals indicated, e.g. bases corresponding to alkali metals selected from alkali metal hydroxides, alkali metal carbonates, alkali metal bicarbonates, alkali metal oxides or alkali metal alkoxides, etc., with the formula NR₄(R₅)(R₆)(R₇) The corresponding alkali of the group is selected from ammonia, ethanolamine, diethanolamine, triethanolamine, triethylamine, quaternary ammonium base and the like.

In the technical scheme, the modified polyacrylamide is prepared from two monomers of acrylamide and 2-acrylamide-2-methylpropanesulfonic acid by an aqueous solution polymerization method, can be purchased from the market, and can also be prepared by conventional free radical copolymerization. The resulting products, whether block or random, are useful in and meet the objectives of the present invention. The modified polyacrylamide in the embodiment of the invention is prepared by mixing acrylamide and 2-acrylamido-2-methylpropanesulfonic acid according to a molar ratio of (0.5-5) to 1, and initiating a free radical polymerization reaction by using water as a solvent and using a conventional free radical initiator.

In the technical scheme, the hydrophobic association polymer is prepared from three monomers, namely acrylamide, 2-acrylamido-2-methylpropanesulfonic acid and 2-acrylamido dodecylsulfonic acid, by an aqueous solution polymerization method, can be obtained from the market, and can also be prepared by conventional free radical copolymerization. The resulting products, whether block or random, are useful in and meet the objectives of the present invention. The hydrophobic association polymer in the embodiment of the invention is prepared by mixing three monomers, namely acrylamide, 2-acrylamido-2-methylpropanesulfonic acid and 2-acrylamido dodecylsulfonic acid, in a molar ratio of 1: 0.5-5: 0.001-0.01, and then initiating a free radical polymerization reaction by using water as a solvent and using a conventional free radical initiator.

The key active ingredient of the oil displacing composition of the present invention is said component (1), and those skilled in the art will appreciate that it may be available in various forms for supply, such as non-aqueous solid form, or aqueous paste form, or aqueous solution form, for ease of transportation and storage or in field use; the water solution form comprises a form of preparing a concentrated solution by using water and a form of directly preparing a flooding composition with concentration required for on-site flooding; the water is not particularly required, and can be deionized water or water containing inorganic mineral substances, and the water containing the inorganic mineral substances can be tap water, oil field formation water or oil field injection water.

The oil displacement composition has good compatibility, and can also contain other treating agents commonly used in the field, such as foaming agents, micromolecular organic matters (such as isopropanol, ethylene glycol monobutyl ether, DMSO and the like) and other oil extraction aids.

In the above technical scheme, the oil-displacing composition obtained in step c or (c) may be obtained by mixing the components according to the required amount by various conventional mixing methods, and when used for oil displacement, the oil-displacing composition is dissolved by water according to the required concentration to obtain the oil-displacing composition for oil displacement; and according to the concentration of the oil displacement composition, dissolving the components in the oil displacement composition in water respectively to obtain the oil displacement composition for oil displacement. The water used in the preparation can be tap water, river water, seawater and oil field formation water; preferred water is: the total mineralization degree of simulated oil field formation water is preferably 50000-250000 mg/L.

In the present invention, the nonionic surfactant represented by the formula (1), the anionic surfactant represented by the formula (2), and the anionic surfactant represented by the formula (3) have EO-PO-EO arrangement in EO and PO segments, and the inventors have surprisingly found that the oil displacement effect of the composition obtained by using such arrangement is far superior to that of EO-PO arrangement or PO-EO arrangement under the conditions of the same structure and the same EO number and PO number.

The invention adopts a physical simulation displacement evaluation method to evaluate the effect, and the specific evaluation method comprises the following steps:

Drying the core at constant temperature to constant weight, and measuring the gas logging permeability of the core; calculating the pore volume of the simulated oil field stratum water saturated core, recording the volume of saturated crude oil by using the crude oil saturated core at the oil displacement temperature, pumping the stratum water at the speed of 0.1ml/min, driving until the water content reaches 100%, calculating the recovery ratio of the crude oil improved by water drive, then transferring the oil displacement composition obtained in the step c or (c) at the speed of 0.1ml/min to 0.1-1 PV (core pore volume), driving the water at the speed of 0.1ml/min to the water content of 100%, and calculating the percentage of the recovery ratio of the crude oil improved on the basis of the water drive.

The dosage or concentration of the surfactant is calculated by the total amount of the nonionic surfactant shown in the formula (1), the single hydrophilic head-based anionic surfactant shown in the formula (2) and the double hydrophilic head-based anionic surfactant shown in the formula (3).

The oil displacement composition and the preparation method thereof can be used for simulating oil field formation water and crude oil with the formation temperature of 75-95 ℃ and the mineralization degree of 50000-250000 mg/L, and the mixed surfactant accounts for 0.005-0.6 wt% and the modified polyacrylamide or the hydrophobic association polymerization accounts for 0-0.3 wt% in percentage by massForming oil displacing composition, measuring apparent viscosity of its water solution, and measuring dynamic interfacial tension value between the oil displacing composition and oil field dewatered crude oil to 10^-2～10^-4mN/m, evaluated in a physical simulation displacement laboratory, the oil displacement composition can improve the crude oil recovery rate to 19.75 percent on the basis of water displacement, and obtains better technical effect.

Drawings

FIG. 1a is a graph of interfacial tension of aqueous solutions of surfactants S-1 to S-3 of different concentrations prepared with a simulated brine A against oil field dehydrated crude oil at 85 ℃.

FIG. 1B is a graph of the interfacial tension of simulated brine B (95 deg.C), S-5 (85 deg.C) versus dehydrated oilfield crude oil for different concentrations of S-1, S-4, and S-5.

FIG. 1c is a graph of the interfacial tension of the simulated brine A solution (85 ℃) and the simulated brine B solution (95 ℃) of S-6 and S-8 with different concentrations on the dehydrated crude oil in the oil field.

Fig. 2 is a flow chart of a simulated core displacement test. Wherein, 1 is a constant flow pump, 2 is a six-way valve, 3 is an intermediate container, 4 is a medicament tank, 5 is a pressure pump, 6 is a six-way valve, 7 is a sand filling pipe, and 8 is a measuring cylinder.

FIG. 3a is a graph of the viscosity of an aqueous solution A of saline 0.15 wt% P1, 0.3 wt% S-1+0.15 wt% P1 after aging at 85 ℃ for various periods of time.

FIG. 3b is a graph of the viscosity of an aqueous solution A of saline 0.1 wt% P2, 0.3 wt% S-1+0.1 wt% P2 after aging at 85 ℃ for various periods of time.

FIG. 3c is a graph of the viscosity of an aqueous solution of saline A at 0.08 wt% P2, 0.3 wt% S-1+0.08 wt% P2 after aging at 75 ℃ for various periods of time.

FIG. 3d is a graph of the viscosity of 0.12 wt% P2, 0.3 wt% S-1+0.12 wt% P2 saline A in water after aging at 95 ℃ for various periods of time.

FIG. 4a is a graph of the interfacial tension of a 0.3 wt% S-1, 0.3 wt% S-1+0.15 wt% P1 brine A aqueous solution after aging at 85 ℃ for various times on oilfield dewatered crude.

FIG. 4b is a graph of the interfacial tension of a 0.3 wt% S-1, 0.3 wt% S-1+0.1 wt% P2 brine A aqueous solution after aging at 85 ℃ for various times on oilfield dewatered crude oil.

FIG. 4c is a graph of the interfacial tension of a 0.3 wt% S-1, 0.3 wt% S-1+0.08 wt% P2 brine A aqueous solution after aging at 75 ℃ for various times on oilfield dewatered crude.

FIG. 4d is a graph of the interfacial tension of a 0.3 wt% S-1, 0.3 wt% S-1+0.12 wt% P2 brine A aqueous solution after aging at 95 ℃ for various times on oilfield dewatered crude.

the invention is further illustrated by the following examples.

Detailed Description

[ example 1 ]

a. The structural formula of the prepared anionic nonionic mixed surfactant is shown in the specification, wherein (1) Z₁＝H，Z₂H, nonionic surfactant; (2) z₁＝H，Z₂＝CH₂COONa, a mono-hydrophilic head-based anionic surfactant; (3) z₁＝Z₂＝

CH₂COONa, an amphiphilic head-based anionic surfactant; m is₁+m₂＝4，n₁+n₂＝35，m₃+m₄＝3。

Adding 261 g (1 mol) of dodecylaniline, 5.2 g of sodium hydroxide and 13.1 g of anhydrous potassium carbonate into a 5L pressure reactor provided with a stirring device, heating to 80-90 ℃, starting a vacuum system, dehydrating for 1 hour under high vacuum, then replacing for 3-4 times with nitrogen, adjusting the reaction temperature of the system to 110 ℃, slowly introducing 178.2 g (4.05 mol) of ethylene oxide, controlling the pressure to be less than or equal to 0.50MPa, after the reaction of the ethylene oxide is finished, slowly introducing 2053.2 g (35.4 mol) of propylene oxide at 150 ℃, controlling the pressure to be less than or equal to 0.60MPa, and after the reaction of the propylene oxide is finished, adjusting the temperature to 140 ℃, and slowly introducing 134.2 g (3.05 mol) of ethylene oxide. After the reaction is finished, the temperature is reduced to 90 ℃, low-boiling-point substances are removed in vacuum, and after cooling, neutralization and dehydration are carried out, 2515.8 g of dodecylaniline polyoxyethylene (4), polyoxypropylene (35) and polyoxyethylene (3) ether are obtained, and the yield is 96.8%.

Dodecylaniline polyoxyethylene (4) polyoxypropylene (35) polyoxyethylene (3) ether 1299.5 g (0.5 mol), 24 g (0.6 mol) sodium hydroxide, 58.3 g (0.5 mol) sodium chloroacetate and 1000 ml toluene/benzene (v/v ═ 1) were mixed in a 5000 ml four-neck flask equipped with a mechanical stirrer, thermometer and reflux condenser, and the mixture was heated to reflux reaction for 7 hours. Cooling, taking 50 g of uniform reaction liquid, acidifying with 20 wt% hydrochloric acid, separating water and inorganic salt, evaporating to remove the solvent, and analyzing the obtained mixture by High Performance Liquid Chromatography (HPLC), wherein the mass percent of the dodecylaniline polyoxyethylene (4) polyoxypropylene (35) polyoxyethylene (3) ether, the dodecylaniline polyoxyethylene (4) polyoxypropylene (35) polyoxyethylene (3) ether acetic acid and the dodecylaniline polyoxyethylene (4) polyoxypropylene (35) polyoxyethylene (3) ether diacetic acid is 49.2:20.0: 30.8. Distilling the residual untreated reaction solution to remove the solvent, adding water and uniformly mixing to obtain the mixed surfactant S-1 containing sodium chloride and sodium hydroxide.

b. The specific compositions of the simulated formation water of the oil field with different divalent cations and total mineralization are shown in table 1. Respectively preparing the S-1 surfactant and modified polyacrylamide (P1, the molar ratio of the copolymer AM/AMPS is 1/1, and the viscosity-average molecular weight is 1450 ten thousand) aqueous solutions prepared in the step a by using oilfield simulated formation water A, stirring for 3 hours, mixing the two solutions to obtain a uniform oil displacement composition of a poly-surfactant binary system, measuring the viscosity and the oil-water interfacial tension of the system, and comparing the system viscosity and the oil-water interfacial tension with S-1 and P1, wherein the composition is shown in Table 2. S-1 aqueous solutions with different concentrations are prepared by using oilfield simulated formation water A and B, and the oil-water interfacial tension of the aqueous solutions is measured, and is shown in figure 1. The viscosity of the oilfield dewatered crude was 2.5mpa.s, the test temperature was 85 ℃, the apparent viscosity was measured by a Brookfield company model III viscometer, usa, and the interfacial tension was measured by a TX500 rotary drop interfacial tensiometer, manufactured by texas university, usa.

c. And drying the artificial core at constant temperature to constant weight, measuring the average diameter and the length of the core, weighing the dry weight of the core, and measuring the gas logging permeability of the core. And (4) simulating a formation water A saturated core by using the oil field, and testing the pore volume of the saturated core. And (4) recording the volume of the saturated crude oil by using the oil field dehydrated crude oil saturated core. And (b) performing water flooding on the simulated formation water A of the oil field at the temperature of 85 ℃ until the water content of the produced liquid reaches 100%, calculating the recovery ratio of the crude oil improved by the water flooding, transferring the polymer-surfactant binary system oil displacing composition synthesized in the step b by 0.3PV (core pore volume), performing water flooding until the water content reaches 100%, calculating the percentage of the recovery ratio of the crude oil improved on the basis of the water flooding, and simultaneously comparing the percentage with the single oil displacing composition injected with the same PV (potential of hydrogen) as shown in the table 2. The gas permeability of the core is measured by an HKGP-3 type compact core gas permeability porosity measuring instrument, and the flow of the adopted simulated core displacement test is shown in figure 2.

[ example 2 ]

a. The same as in example 1, except that after the completion of the reaction, all the reaction solutions were acidified, washed with water and the solvent was distilled off, the resulting mixture was mixed with water, and the pH of the system was adjusted to 12 with a 30 wt% aqueous solution of sodium hydroxide to obtain the desired mixed surfactant S-2.

b. And (b) preparing aqueous solutions of the S-2 prepared in the step a and the modified polyacrylamide (P1, the molar ratio of the copolymer AM/AMPS is 1/1, and the viscosity-average molecular weight is 1450 ten thousand) by using the oilfield simulated formation water A, stirring for 4 hours, and obtaining the results shown in the table 3 in the rest of the example 1 b. The oil-water interfacial tension of S-2 aqueous solutions of different concentrations is shown in FIG. 1.

c. The indoor simulated oil displacement test was carried out in the same manner as in example 1, and the results are shown in table 3.

[ example 3 ]

a. The structural formula of the prepared anionic nonionic mixed surfactant is shown in the specification, wherein (1) Z₁＝H，Z₂H, nonionic surfactant; (2) z₁＝H，Z₂＝CH₂COOH.HN(CH₂CH₂OH)₂A single hydrophilic head based anionic surfactant; (3) z₁＝Z₂＝CH₂COOH.HN(CH₂CH₂OH)₂A hydrophilic-head-based anionic surfactant; m is₁+m₂＝4，n₁+n₂＝35，m₃+m₄＝3。

The same as [ example 2 ] except that the pH of the system was adjusted to 12 by replacing 30 wt% aqueous sodium hydroxide solution with 95% diethanolamine to obtain the desired mixed surfactant S-3.

b. And (b) preparing aqueous solutions of S-3 and modified polyacrylamide (P1, the molar ratio of the copolymer AM/AMPS is 1/1, and the viscosity average molecular weight is 1450 ten thousand) prepared in the step a respectively by using the oilfield simulated formation water A, stirring for 4 hours, and obtaining the results shown in the table 4 in the rest [ example 1 ] b. The oil-water interfacial tension of S-3 aqueous solutions of different concentrations is shown in FIG. 1.

c. the indoor simulated oil displacement test was carried out in the same manner as in example 1, and the results are shown in table 4.

[ example 4 ]

a. the structural formula of the prepared anionic nonionic mixed surfactant is shown in the specification, wherein (1) Z₁＝H，Z₂H, nonionic surfactant; (2) z₁＝H，Z₂＝CH₂CH₂CH₂SO₃Na, single hydrophilic head based anionic surfactant; (3) z₁＝Z₂＝CH₂CH₂CH₂SO₃Na, an amphiphilic head-based anionic surfactant; m is₁+m₂＝3，n₁+n₂＝10，m₃+m₄＝3。

325 g (1 mol) of icosaediamine and 9.7 g of potassium hydroxide are added into a 2L pressure reactor provided with a stirring device, the dehydration and nitrogen replacement are carried out in the same way as in example 1, the reaction temperature of the system is adjusted to 120 ℃, 134.2 g (3.05 mol) of ethylene oxide is slowly introduced, the pressure is controlled to be less than or equal to 0.60MPa, the temperature is adjusted to 130 ℃ after the reaction of the ethylene oxide is finished, 585.8 g (10.1 mol) of propylene oxide is slowly introduced, the pressure is controlled to be less than or equal to 0.60MPa, and the temperature is adjusted to 140 ℃ after the reaction of the propylene oxide is finished, 134.2 g (3.05 mol) of ethylene oxide is slowly introduced. After the reaction is finished, the temperature is reduced to 90 ℃, low-boiling-point substances are removed in vacuum, neutralization and dehydration are carried out after cooling, 1126.2 g of the icosapolyoxyethylene (3) polyoxypropylene (10) polyoxyethylene (3) ether are obtained, and the yield is 96.3%.

Icosamethylenediamine polyoxyethylene (3) polyoxypropylene (10) polyoxyethylene (3) ether 584.5 g (0.5 mol), 81.0 g (1.5 mol) sodium methoxide, 122 g (1.0 mol) 1, 3-propanesultone and 800 ml cyclopentanone were mixed in a 5000 ml four-neck flask equipped with a mechanical stirrer, a thermometer and a reflux condenser, and after the addition, the temperature was raised to reflux for 5 hours. Cooling, acidifying with 30 wt% phosphoric acid, separating water and inorganic salt, evaporating to remove solvent, and analyzing the obtained mixture by High Performance Liquid Chromatography (HPLC), wherein the mass percent of the icosapolyoxyethylene (3) polyoxypropylene (10) polyoxyethylene (3) ether, the icosapolyoxyethylene (3) polyoxypropylene (10) polyoxyethylene (3) ether propanesulfonic acid, and the mass percent of the icosapolyoxyethylene (3) polyoxypropylene (10) polyoxyethylene (3) ether dipropylsulfonic acid is 1.2:27.8: 71.0. The product was mixed with water, and the pH of the system was adjusted to 13 with a 15% aqueous solution of sodium hydroxide to obtain the desired mixed surfactant S-4.

b. Aqueous solutions of S-4 and hydrophobically associating polymer (P2, molar ratio of copolymer AM/AMPS/2-acrylamidododecylsulfonic acid 1/0.5/0.002, viscosity average molecular weight 1800 ten thousand) prepared in step a were prepared from the oilfield formation-simulating water B and stirred for 4 hours, and the results are shown in table 5. The oil-water interfacial tension of S-4 aqueous solutions of different concentrations is shown in FIG. 1.

c. An indoor simulated oil displacement test was carried out in the same manner as in example 1, except that the oil displacement temperature was 95 ℃, and the results are shown in table 5.

[ example 5 ]

a. The same as [ example 4 ] a, except that the amount of sodium methoxide charged was changed to 1.25mol, the amount of 1, 3-propanesultone charged was changed to 0.8mol, and the obtained mixture was analyzed by High Performance Liquid Chromatography (HPLC), and the mass percentages of the behenyl amine polyoxyethylene (3) polyoxypropylene (10) polyoxyethylene (3) ether, the behenyl amine polyoxyethylene (3) polyoxypropylene (10) polyoxyethylene (3) ether propanesulfonic acid, and the behenyl amine polyoxyethylene (3) polyoxypropylene (10) polyoxyethylene (3) ether dipropylsulfonic acid were 17.6:29.2: 53.2. The product was mixed with water, and the pH of the system was adjusted to 13 with a 15% aqueous solution of sodium hydroxide to obtain the desired mixed surfactant S-5.

b. The results are shown in Table 5, as in example 4 b. The oil-water interfacial tension of S-5 aqueous solutions of different concentrations is shown in FIG. 1.

c. The indoor simulated oil displacement test was carried out in the same manner as in example 4, and the results are shown in table 6.

[ example 6 ]

a. The structural formula of the prepared anionic nonionic mixed surfactant is shown in the specification, wherein (1) Z₁＝H，Z₂H, nonionic surfactant; (2) z₁＝H，Z₂＝CH₂CH₂SO₃Na, single hydrophilic head based anionic surfactant; (3) z₁＝Z₂＝CH₂CH₂SO₃Na, an amphiphilic head-based anionic surfactant; m is₁+m₂＝6，n₁+n₂＝25，m₃+m₄＝15。

199 g (1 mol) of tridecylamine and 4.8 g of potassium hydroxide were added into a 2L pressure reactor equipped with a stirring device, the reaction temperature of the system was adjusted to 110 ℃ and 266.2 g (6.05 mol) of ethylene oxide was slowly introduced with water and nitrogen substitution as in example 1, the pressure was controlled to be less than or equal to 0.60MPa, 1467.4 g (25.3 mol) of propylene oxide was slowly introduced at 130 ℃ after the reaction of ethylene oxide was completed, the pressure was controlled to be less than or equal to 0.60MPa, and 668.8 g (15.2 mol) of ethylene oxide was slowly introduced with temperature adjusted to 140 ℃ after the reaction of propylene oxide was completed. After completion of the reaction, the reaction mixture was worked up in the same manner as in example 1 to obtain 2421.2 g of tridecylamine polyoxyethylene (6) polyoxypropylene (25) polyoxyethylene (15) ether, yield 94.1%.

Tridecylamine polyoxyethylene (6) polyoxypropylene (25) polyoxyethylene (15) ether 1286.5 g (0.5 mol) was mixed with 50 g (1.25 mol) sodium hydroxide, 83.3 g (0.5 mol) sodium 2-chloroethanesulfonate and 800 ml toluene in a 5000 ml four-neck flask equipped with a mechanical stirrer, thermometer and reflux condenser and heated to reflux for 6 hours. Cooling, taking 50 g of uniform reaction liquid, acidifying with 35 wt% sulfuric acid, separating water and inorganic salt, evaporating the solvent, and analyzing the obtained mixture by High Performance Liquid Chromatography (HPLC), wherein the mass percent of the tridecylamine polyoxyethylene (6) polyoxypropylene (25) polyoxyethylene (15) ether, the tridecylamine polyoxyethylene (6) polyoxypropylene (25) polyoxyethylene (15) ether ethanesulfonic acid, the tridecylamine polyoxyethylene (6) polyoxypropylene (25) polyoxyethylene (15) ether diethylsulfonic acid is 48.5:25.1: 26.4. Distilling the residual untreated reaction solution to remove the solvent, adding water and uniformly mixing to obtain the mixed surfactant S-6 containing sodium chloride and sodium hydroxide.

b. And (b) preparing aqueous solutions of S-6 and modified polyacrylamide (P1, the molar ratio of the copolymer AM/AMPS is 1/1, and the viscosity average molecular weight is 1450 ten thousand) prepared in the step a respectively by using the oilfield simulated formation water A, stirring for 4 hours, and obtaining the results shown in the table 6 as the rest [ example 1 ] b. The oil-water interfacial tension of S-6 aqueous solutions of different concentrations is shown in FIG. 1.

c. The indoor simulated oil displacement test was carried out in the same manner as in example 1, and the results are shown in table 7.

[ example 7 ]

a. The same as in example 6 a, except that after the completion of the reaction, all the reaction solutions were acidified, washed with water and the solvent was distilled off, the resulting mixture was mixed with water, and the pH of the system was adjusted to 13 with a 30 wt% aqueous solution of sodium hydroxide to obtain the desired mixed surfactant S-7.

b. The results are shown in Table 7, as in example 6 b. The oil-water interfacial tension of S-7 aqueous solutions of different concentrations is shown in FIG. 1.

c. The results of the indoor simulated oil displacement test conducted in the same manner as in example 1 are shown in Table 8.

[ example 8 ]

a. The structural formula of the prepared anionic nonionic mixed surfactant is shown in the specification, wherein (1) Z₁＝H，Z₂H, nonionic surfactant; (2) z₁＝H，Z₂＝CH₂CH₂SO₃H.N(CH₂CH₃)₃A single hydrophilic head based anionic surfactant; (3) z₁＝Z₂＝CH₂CH₂SO₃H.N(CH₂CH₃)₃Double hydrophilic head baseAn anionic surfactant; m is₁+m₂＝6，n₁+n₂＝25，m₃+m₄＝15。

The same as [ example 7 ] except that the pH of the system was adjusted to 13 by replacing 30 wt% aqueous sodium hydroxide solution with 90% triethylamine to obtain the desired mixed surfactant S-8.

b. The results are shown in Table 8, as in example 6 b. The oil-water interfacial tension of S-8 aqueous solutions of different concentrations is shown in FIG. 1.

c. The results of the indoor simulated oil displacement test conducted in the same manner as in example 1 are shown in Table 9.

[ example 9 ]

The same as example 1, except that the polymer was a hydrophobically associating polymer (P2, molar ratio of co-AM/AMPS/2-acrylamidododecylsulfonic acid 1/0.5/0.002, viscosity average molecular weight 1800 ten thousand), oil displacement temperature was 85 ℃, 75 ℃ and 95 ℃, and the results are shown in tables 10 to 12.

[ example 10 ]

the polymer surfactant binary system oil displacement composition prepared in example 1 and example 9 is filled into a 50 ml ampoule bottle, and is placed into an oven for thermal stability test after being deoxidized and unsealed in vacuum, and is compared with the polymer with the same concentration, and the thermal stability test is shown in figures 3 a-d; the oil-water interfacial tension of the polyepitometer binary system flooding composition on the oil field dehydrated crude oil after different aging times is measured and compared with the surfactant with the same concentration, which is shown in figures 4 a-d.

[ COMPARATIVE EXAMPLE 1 ]

an amount of a comparative surfactant was dissolved in simulated brine a or B of various degrees of mineralization, and the oil-water interfacial tension of the comparative surfactant solution on dehydrated crude oil was measured and compared with the surfactants prepared in the corresponding examples, and the results are shown in table 13, in which the concentration of the surfactant was 0.1 wt%.

In Table 13, S-9 is dodecylanilinoethylene (4) polyoxypropylene (35) polyoxyethylene (3) ether; s-10 is behenyl diamine polyoxyethylene (3) polyoxypropylene (10) polyoxyethylene (3) ether; s-11 is tridecylamine polyoxyethylene (6) polyoxypropylene (25) polyoxyethylene (15) ether.

[ COMPARATIVE EXAMPLE 2 ]

The same as in example 1, example 4 and example 6, except that propylene oxide and ethylene oxide were not reacted successively in steps, ethylene oxide and propylene oxide were mixed in advance in an amount required for polymerization and then reacted in one step, and the rest were the same, to obtain mixed surfactants S-12 to S-14. The interfacial tension of the oil field dehydrated crude oil was measured and the results are shown in Table 14, wherein the surfactant concentration was 0.1 wt%.

[ COMPARATIVE EXAMPLE 3 ]

The same as in example 2, except that the amount of sodium chloroacetate was changed to 349.5 g (3 mol) and the amount of sodium hydroxide was changed to 100 g (2.5 mol), and the other was the same, and the mass ratio of dodecylanilinepolyoxyethylene (4) polyoxypropylene (35) polyoxyethylene (3) ether diacetic acid to dodecylanilinepoxyethylene (4) polyoxypropylene (35) polyoxyethylene (3) ether was 1:0.013 by (HPLC) analysis of the product obtained after evaporation of the solvent. The pH of the system was adjusted to 12 with 30 wt% sodium hydroxide and mixed well to obtain surfactant S-15. The oil-water interfacial tension of the dehydrated crude oil was measured, and the concentration of the surfactant was 0.1 wt% as compared with that of S-2, and the results are shown in Table 14.

[ COMPARATIVE EXAMPLE 4 ]

The same as example 1, except that high molecular weight anionic polyacrylamide P3 (viscosity average molecular weight 2500 ten thousand) was used instead of modified polyacrylamide P1, the same applies, and the results are shown in FIG. 15.

TABLE 1

Simulated salt water	Ca²⁺(mg/L)	Mg²⁺(mg/L)	TDS(mg/L)
				A	1500	525	75000
B	5000	1500	255000

TABLE 2

TABLE 3

TABLE 4

TABLE 5

TABLE 6

TABLE 7

TABLE 8

TABLE 9

Table 10 (oil displacement temperature: 85 degree)

Table 11 (oil displacement temperature: 75 deg.C)

Table 12 (oil displacement temperature: 95 degree)

Watch 13

Surface active agent	Salt water	Temperature (. degree.C.)	IFT(mN/m)
				S-1	A	85	0.00077
S-2	A	85	0.00053
				S-3	A	85	0.00112
S-9	A	85	2.3455
				S-4	B	95	0.00129
S-10	B	95	3.5512
				S-5	A	85	0.00071
S-10	A	85	2.7796
				S-6	A	85	0.00056
S-7	A	85	0.00087
				S-8	A	85	0.00145
S-11	A	85	1.04522

TABLE 14

Surface active agent	salt water	Temperature (. degree.C.)	IFT(mN/m)
				S-1	A	85	0.00077
S-12	A	85	0.00898
				S-4	B	95	0.00129
S-13	B	95	0.01255
				S-6	A	85	0.00056
S-14	A	85	0.00733
				S-2	A	85	0.00053
S-15	A	85	3.7764

watch 15

Claims

1. An oil displacement composition comprises the following components in parts by weight:

1)1 part of a surfactant;

2)0 to 50 parts and more than 0 part of a polymer;

R₁And R₂And R₃Are all independently selected from C₄～C₄₀Aliphatic hydrocarbon radical of or consisting of C₄～C₃₀Linear or branched, saturated and unsaturated hydrocarbyl-substituted aryl groups; m1, m2, m3 and m4 are independently selected from 0-50, but m1 and m2, and m3 and m4 cannot be 0 at the same time; n1 and n2 are independently selected from 0-100, but n1 and n2 cannot be 0 at the same time; r1, r2, r3 and r4 are independently selected from 0-50, but r1 and r2, and r3 and r4 cannot be 0 at the same time; s1 and s2 are independently selected from 0-100, but s1 and s2 cannot be 0 at the same time; p1, p2, p3 and p4 are independently selected from 0-50, but p1 and p2, and p3 and p4 cannot be 0 at the same time; q1 and q2 are independently selected from 0-100, but q1 and q2 cannot be 0 at the same time; the m1+ m2 is 2-10, m3+ m4 is 2-20, n1+ n2 is 5-40 and/or r1+ r2 is 2-10, r3+ r4 is 2-20, s1+ s2 is 5-40 and/or p1+ p2 is 2-10, p3+ p4 is 2-20, and q1+ q2 is 5-40; z₁And Z₂And Z₃Are each-R₀₁Y₁、－R₀₂Y₂、－R₀₃Y₃；R₀₁and R₀₂And R₀₃Is selected from C₁～C₅Alkylene or hydroxy-substituted alkylene of, Y₁And Y₂And Y₃Selected from SO₃M or COOW, MAnd W is independently selected from hydrogen, alkali metal or from the formula NR₄(R₅)(R₆)(R₇) A group shown, R₄、R₅、R₆、R₇Is independently selected from H, (CH)₂)_pOH or (CH)₂)_qCH₃P is any integer of 2 to 4, and q is any integer of 0 to 5.

2. The flooding composition of claim 1, wherein R is₁Or R₂or R₃At least one of them is C₆～C₂₀Or from C₈～C₁₆Alkyl-substituted phenyl.

3. The flooding composition of claim 1, wherein p is 2 and q is 0-1.

4. The flooding composition of claim 1, wherein the polymer is at least one of xanthan gum, hydroxymethyl cellulose, hydroxyethyl cellulose, modified polyacrylamide, hydrophobically associative polymer.

5. The oil displacement composition of claim 4, wherein the modified polyacrylamide is prepared by copolymerizing acrylamide and a temperature-resistant and salt-resistant monomer, the molar ratio of the acrylamide to the temperature-resistant and salt-resistant monomer is (0.1-40) to 1, the hydrophobic association polymer is prepared by copolymerizing the acrylamide, the temperature-resistant and salt-resistant monomer and a hydrophobic monomer, and the molar ratio of the acrylamide, the temperature-resistant and salt-resistant monomer to the hydrophobic monomer is 1: (0.1-40): (0.001-0.05).

6. The flooding composition of claim 5, wherein the modified polyacrylamide has a viscosity average molecular weight of 800-2500 ten thousand, and the hydrophobically associating polymer has a viscosity average molecular weight of 1000-2500 ten thousand. .

7. A method of preparing the flooding composition of any one of claims 1 to 6 comprising the steps of:

wherein Z is₀₁is-R₀₂Y₀₁；Y₀₁Selected from SO₃M₁Or COOW₁，M₁And W₁Is an alkali metal, X₁Selected from chlorine, bromine or iodine;

8. The method of claim 7, wherein R is the same as R in step b₁N((CH₂CH₂O)_m1(CHCH₃CH₂O)_n1(CH₂CH₂O)_m3H)((CH₂CH₂O)_m2)(CHCH₃CH₂O)_n2(CH₂CH₂O)_m4H):X₁R₀₁Y₀₁The molar ratio of the alkali metal hydroxide or alkali metal alkoxide is 1 (1-2) to 1-3.

9. A method for preparing the flooding composition of any one of claims 1 to 6, comprising the steps of:

(b) Reacting the product obtained in the step a of claim 7 with 1, 3-propane sultone and alkali metal hydroxide or alkali metal alkoxide in a molar ratio of 1 (1-2) to (1-4) in a solvent at a reaction temperature of 50-120 ℃ for 3-15 hours to obtain a mixture containing a nonionic surfactant represented by the formula (1) and a mono-hydrophilic head-based anionic surfactant represented by the formula (6) and a bi-hydrophilic head-based anionic surfactant represented by the formula (7);

Wherein Z'₀₁is-CH₂CH₂CH₂SO₃M₂；M₂Is an alkali metal;

10. The method of claim 9, wherein R is the member of step (b)₁N((CH₂CH₂O)_m1(CHCH₃CH₂O)_n1(CH₂CH₂O)_m3H)((CH₂CH₂O)_m2)(CHCH₃CH₂O)_n2(CH₂CH₂O)_m4H) The molar ratio of the 1, 3-propane sultone to the alkali metal hydroxide or the alkali metal alkoxide is 1 (1-2) to 1-3.