RU2563642C2 - Oil production method using surfactants based on butylene-oxide-containing alkyl alkoxylates - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention is referred to an oil production method by flooding with the Windsor III microemulsion, wherein at least through one injector an aqueous compound of surfactants is injected to the oil deposit in order to reduce surface tension between oil and water up to values less than 0.1 mN/m, and the above compound includes at least one surfactant, while from the oil deposit raw oil is extracted at least through one producer; the method is featured by the usage of the aqueous compound of surfactants containing at least one surfactant with the general formula of R¹-O-(D)_n-(B)_m-(A)_l-XY^-M⁺, where R¹ stands for a linear or branched saturated or unsaturated aliphatic and/or aromatic residue with the number of carbon atoms from eight up to thirty, A stands for an ethylene oxide group, B stands for a propylene oxide group and D stands for a butylene oxide group, l stands for a number from 0 up to 99, m stands for a number from 0 up to 99 and n stands for a number from 1 up to 99, X stands for an alkyl or alkylene group with the number of carbon atoms from 0 up to 10, M⁺ stands for a cation and Y^- is selected from the following groups: sulphate groups, sulphonate groups, carboxylate groups and phosphate groups, at that A, B and D groups may have statistic or alternate distribution or they may be present as two, three, four or several units in any sequence, the amount of l+m+n lies within limits from 3 up to 99 and contents of 1,2-butylene oxide groups on the basis of the whole quantity of the butylene oxide groups is not less than 80%.

EFFECT: this substance features special efficiency when it is used at flooding with surfactants.

7 cl, 7 tbl

Description

The invention relates to a method for oil production by flooding with a Winsor type III microemulsion, according to which the aqueous composition of surfactants, comprising at least one ionic surfactant of the general formula

$${\text{R}}^{\text{one}}{\text{-O- (D)}}_{\text{n}}{\text{- (B)}}_{\text{m}}{\text{- (A)}}_{\text{l}}{\text{-XY}}^{\text{-}}{\text{M}}^{+}$$

pumped under pressure into the oil field through injection wells and pumped crude oil from the field through production wells. The invention also relates to the corresponding general formula for ionic surfactants and to a process for their preparation.

In natural oil fields, oil is located in the voids of the porous rocks accumulating it, which are closed on the way to the surface by impermeable overburden layers. Voids can be very small gaps, capillaries, pores, etc. Thin tubules of pores may have a diameter of, for example, only about 1 μm. Together with oil and associated gas in the oil field there is more or less water with a high salt content.

In oil production, in general, primary, secondary and tertiary production should be distinguished. In primary production, oil flows through drilled wells to the surface under the influence of its own pressure in the oil reservoir.

In accordance with this, after the primary production, the secondary production phase begins. In secondary production, in addition to the wells that are used to extract oil, they are called production wells, and additional wells are reached that reach oil formations. Through these so-called injection wells, water is pumped into the oil field to maintain reservoir pressure or to increase it again. The consequence of water injection is the slow displacement of oil through empty spaces in the geological formation in the direction from injection wells to production wells. However, this only applies as long as these empty spaces are completely filled with oil and viscous oil can be pushed with water. As soon as easily flowing water breaks through the gaps in the rock, it begins to flow along the path of least resistance, that is, through the formed channels, and no longer pushes oil in front of it.

As a rule, using primary and secondary production, it is possible to extract only about 30-35% of the total amount of oil deposited in the field.

It is known that the oil yield can be further increased with the help of measures that make up the tertiary phase of oil field development. An overview of tertiary oil production methods can be found, for example, in Journal of Petroleum Science of Engineering 19 (1998) on pages 265 to 280. Tertiary oil production may include thermal methods whereby hot water is supplied to an oil field under pressure. or hot steam. The consequence of this is a decrease in oil viscosity. Gases such as carbon dioxide or nitrogen may also be used as void-filling media.

Tertiary oil production also includes methods in which suitable chemicals are used as an aid to oil recovery. With their help, it is possible to change the situation at the end of water flooding and to extract oil that had been retained before in the rock.

Oil, which at the end of secondary production is retained in the rock pores of the field, is affected by viscosity and capillary forces, and the ratio of these two forces determines the microscopic extraction of oil. The role of these forces is described using a dimensionless parameter, the so-called capillary number. It is the ratio of the viscosity forces (the product of the velocity and viscosity of the displacing phase) to the capillary forces (the product of the surface tension between oil and water and the wetting of the rock):

$$N_c=\frac{\mu v}{\sigma \cos \theta }$$

In this equation, µ means the viscosity of the fluid that drives the oil, v means the Darcy velocity (flowing through a unit of surface), σ means the surface tension between the fluid that drives the oil and the oil, and θ means the contact angle between the oil and the rock (C. Melrose, CF Brandner, J. Canadian Petr. Techn. 58, October-December, 1974). The higher the capillary number, the higher the mobility of the oil and the associated degree of oil recovery.

It is known that by the end of the secondary oil production, the capillary number is about 10 ^-6 , and in order to obtain additional oil, the capillary number must be raised to a value from about 10 ^-3 to about 10 ^-2 .

To do this, you can carry out a special type of water flooding - the so-called water flooding with Winsor type III microemulsion. When flooding with Winsor type III microemulsion, the injected surfactants must form a Winsor type III microemulsion with an aqueous and oil phase present in the oil reservoir. In the case of the Winsor type III microemulsion, this is not an emulsion with particularly small droplets, but a thermodynamically stable liquid mixture of water, oil and surfactants. It has three advantages:

- when it is formed, a very low surface tension σ is achieved between the oil and the aqueous phase,

- it, as a rule, has a very low viscosity and therefore is not held by the porous matrix,

- it is formed even with minimal energy influences and can remain stable for an infinitely long period of time (classical emulsions, in contrast to this, require more significant shear forces that almost never occur in the deposit, in addition, they are stabilized only by kinetic factors).

The Winsor Type III microemulsion is in equilibrium with excess water and excess oil. Under such conditions of microemulsion formation, surfactants are located on the interface between oil and water and, in a particularly preferred case, reduce the surface tension σ to values less than 10 ^-2 mN / m (ultralow tension between phases). To obtain an optimal result, the proportion of microemulsions in the water-microemulsion-oil system with a certain amount of surfactant should, of course, be as significant as possible, since even lower surface tension values can be achieved.

As a result of this, oil droplets can change their shape (the surface tension between oil and water decreases so much that the tendency to a state with the smallest interface is no longer present and the spherical shape preference rule no longer applies) and therefore they begin to squeeze through the capillary holes under the action of the injected water.

A Winsor type III microemulsion is formed when all the phase interfaces between oil and water are coated with a surfactant and there is an excess amount of surfactant. Accordingly, it is a reservoir for surfactants that set a very low surface tension between the oil and water phases. Due to the very low viscosity of the Winsor type III microemulsion, it passes through the porous rock of the deposit with water during water flooding (in contrast, emulsions can linger in the porous matrix and clog the deposits). When a Winsor type III microemulsion encounters a phase-boundary between oil and water not yet coated with a surfactant, a microemulsion surfactant can significantly reduce the surface tension of this new phase interface, which can lead to improved oil mobility (e.g., the result of a change in the shape of oil droplets).

The oil droplets may then combine to form a continuous oil field. This gives a double advantage:

firstly, when a continuous oil field is advanced through new porous rocks, oil droplets in them merge with the oil field,

in addition, the combination of oil droplets in an oil field significantly reduces the interface between oil and water, and as a result, the release of an already unnecessary surfactant occurs. The released surfactant can then, as presented above, improve the mobility of the oil droplets remaining in the geological formation.

From this it follows that Winsor type III microemulsions are an extremely effective agent, and in contrast to the emulsion flooding method, they require significantly less surfactant. In microemulsion flooding, surfactants can usually be injected together with additional solvents and / or basic salts (if necessary in the presence of means for the formation of chelate structures). Following this, a polymer solution is pumped, which acts as a thickener for regulating mobility. Another option is represented by injecting a mixture of a thickening polymer and surfactants, additional solvents and / or basic salts (if necessary with chelating agents), followed by injecting a solution of a thickening polymer to regulate mobility. As a rule, these solutions should be transparent in order to avoid clogging of the deposit.

The requirements for surfactants for tertiary oil production are significantly different from the requirements for surfactants used for another purpose: surfactants suitable for tertiary oil production should reduce the surface tension between water and oil (usually it is about 20 mN / m) to particularly low values of less than 10 ^-2 mN / m in order to give the oil sufficient mobility. This effect should be manifested at temperatures typical of deposits from about 15 ° C to 130 ° C in the presence of water with a high salt content, in particular also in the presence of high concentrations of calcium and / or magnesium ions; surfactants must also be soluble in high salt formation waters.

To bring them in line with these requirements, mixtures of surfactants, in particular mixtures of anionic and nonionic surfactants, were most often proposed.

US Pat. No. 3,890,239 teaches a combination of organic sulfonates with C ₈ -C ₂₀ -AO-H type alkyl alkoxylates (AO means alkylene oxide of two to six carbon atoms) with C ₈ -C ₂₀ -AO-sulfate anionic surfactants or, respectively, C8-C ₂₀ -AO-sulfonate. The alkylene oxide data in the description of US Pat. No. 3,890,239 is presented in its most general form. At the same time, the examples are exclusively about ethylene oxide.

US patent No. 4448697 relates to the use of type C ₁ -C ₆ - (AO) _1-40 -EO _≥10 -H type alkyl alkoxylates in combination with one anionic surfactant. In this case, AO may mean 1,2-butylene oxide or 2,3-butylene oxide.

US Pat. No. 4,460,481 discloses surfactants such as alkylarylalkoxy sulfates or sulfonates, respectively. The alkylene oxide may be ethylene oxide, propylene oxide or butylene oxide. In this case, the condition is valid, according to which ethylene oxide constitutes the bulk of alkylene oxides. A more detailed description of butylene oxide is missing.

Application parameters such as, for example, the type, concentration and ratio of the surfactants used in the mixture are determined by a specialist in accordance with the conditions existing in a particular oil-bearing geological formation (for example, temperature and salt content).

As presented above, oil productivity is proportional to the capillary number. It is the higher, the lower the surface tension between oil and water. Low values of surface tension become all the more difficult to achieve, the higher the average number of carbon atoms in crude oil. To achieve low surface tension values, surfactants with a long alkyl residue are suitable. The longer the alkyl residue, the more effectively the surface tension is reduced. However, the availability of such compounds is very limited.

Accordingly, the object of the invention was to provide a particularly effective surfactant for use in flooding using surfactants, and also to develop an improved method for tertiary oil recovery.

In accordance with this, a method for tertiary oil production using water flooding with the formation of a Winsor type III microemulsion is developed, during the implementation of which an aqueous composition of surfactants containing at least one ionic surfactant is pumped into the oil field through at least one injection well while the surface tension between oil and water is reduced to values less than 0.1 mN / m, preferably to values less than 0.05 mN / m, in a particularly preferred case to values enee 0.01 mN / m, and from the deposit through at least one production well recovered crude oil, with a composition to the surfactants is at least one surfactant of the general formula

$${\text{R}}^{\text{one}}{\text{-O- (D)}}_{\text{n}}{\text{- (B)}}_{\text{m}}{\text{- (A)}}_{\text{l}}{\text{-XY}}^{\text{-}}{\text{M}}^{+}$$

Where

R ¹ means a linear or branched saturated or unsaturated aliphatic and / or aromatic hydrocarbon residue with the number of carbon atoms from eight to thirty,

And means an ethylene oxide group,

B means propylene oxide group,

D is a butylene oxide group,

l means a number from 0 to 99,

m means a number from 0 to 99 and

n means a number from 1 to 99,

X is an alkyl or alkylene group with carbon numbers from 0 to 10,

M ⁺ means cation and

Y ^- selected from the group: sulfate groups, sulfonate groups, carboxylate groups and phosphate groups, while

groups A, B and D may have a statistical or alternating distribution, or they may be present in the form of two, three, four or several blocks in any sequence, the sum l + m + n lies in the range from 3 to 99 and the content is 1.2- butylene oxide groups based on the total number of butylene oxide groups is at least 80%.

In addition, a surfactant mixture is prepared for oil production containing at least one ionic surfactant corresponding to the above general formula.

The following are more detailed characteristics of the invention.

When implementing the method of oil production by flooding with the Winsor type III microemulsion as described above, an aqueous composition of surfactants is used containing at least one surfactant of the general formula given. In addition, the composition may contain other surfactants and / or other components.

In accordance with the invention, the method of tertiary oil production by water flooding with Winsor type III microemulsion due to the use of the surfactant according to the invention, the surface tension between oil and water decreases to values less than 0.1 mN / m, preferably to values less than 0.05 mN / m, in a particularly preferred case, to values less than 0.01 mN / m. As a result, the surface tension between oil and water decreases to values in the range from 0.1 to 0.0001 mN / m, in the preferred case to values in the range from 0.05 mN / m to 0.0001 mN / m, in particular preferably up to values ranging from 0.01 mN / m to 0.0001 mN / m.

^. At least one surfactant must be represented by the general formula $${\text{R}}^{\text{one}}{\text{-O- (D)}}_{\text{n}}{\text{- (B)}}_{\text{m}}{\text{- (A)}}_{\text{l}}{\text{-XY}}^{\text{-}}{\text{M}}^{+}$$

^.

In the composition with surfactants in accordance with the methods for their preparation, other various surfactants corresponding to this general formula may also be present.

The residue R ¹ is a linear or branched aliphatic and / or aromatic hydrocarbon residue with a carbon number of eight to thirty, preferably with a carbon number of nine to thirty, in a particularly preferred case of a carbon number of ten to twenty eight.

According to a particularly preferred embodiment of the invention, the residue R ¹ is a heptadecyl residue of an isomeric structure or a residue based on a mixture of fatty alcohols with sixteen and eighteen carbon atoms entering the market (alcohols C ₁₆ H ₃₃ / C ₁₈ H ₃₇ ) or it is derived from market 2-hexadecyl-1-ol, i.e. hexadecyl alcohol, obtained by Guerbet reactions, or entering the market of 2-decyl-tetradecanol, i.e. C ₂₄ -alcohol obtained by Guerbet reactions, or it is derived from the incoming and the market is 2-dodecyl-hexadecanol, i.e. C ₂₈ -alcohol obtained by the Guerbet reaction.

It is particularly preferred that, in the case of linear alcohols, n takes values from 3 to 10 and m takes values from 5 to 9, while in the case of branched alcohols n takes values from 2 to 10 and m takes values from 5 to 9. Moreover, in each In a separate case, it is preferable when D consists of more than 80% 1,2-butylene oxide, and alkylene oxides, starting from the alcohol residue, have a DBA sequence. Alkylene oxides are more than 90% assembled in blocks.

In a particularly preferred case, we are talking about a linear or branched aliphatic hydrocarbon residue, in particular, a linear or branched aliphatic hydrocarbon residue with the number of carbon atoms from ten to twenty eight.

A branched aliphatic hydrocarbon residue has, as a rule, a degree of branching from 0.1 to 5.5, preferably from 1 to 3.5. The concept of “degree of branching” is used in this way in a fundamentally known way as the number of methyl groups in an alcohol molecule reduced by one. The average degree of branching is the average statistical value of the degrees of branching of all the molecules in one sample.

In the above formula, A is an ethylene oxide group, B is a propylene oxide group, and D is a butylene oxide group.

In the above formula, 1, m and n are integers. However, one skilled in the art of polyalkoxylates will understand that this provision only refers to the determination of a single surfactant. In the case of mixtures of surfactants or, respectively, compositions with surfactants, which include several surfactants of this general formula, the numbers 1, type are the average values for all molecules of surfactants , since when alkoxylating an alcohol with ethylene oxide or, respectively, propylene oxide, as well as, respectively, butalene oxide, in each case a certain distribution of chain lengths is obtained. This distribution can be represented in a generally known manner in the form of the so-called polydispersity D. When D = M _w / M _n , it is equal to the ratio of the mass-average molecular weight to the number-average molecular weight. Polydispersity can be determined by methods known to those skilled in the art, for example, by gel permeation chromatography.

In the above general formula, 1 means a number from 0 to 99, preferably from 1 to 40, in a particularly preferred case from 1 to 20.

In the above general formula, m means a number from 0 to 99, preferably from 1 to 20, in a particularly preferred case from 5 to 9.

In the above general formula, n means a number from 1 to 99, preferably from 2 to 30, in a particularly preferred case from 2 to 10.

In accordance with the invention, the sum of 1 + m + n is equal to a number that lies in the range from 3 to 99, preferably in the range from 5 to 50, in a particularly preferred case in the range from 8 to 39.

In accordance with the present invention, the content of 1,2-butylene oxide groups based on the total number of butylene oxide groups (D) is not less than 80%, preferably not less than 85%, more preferably not less than 90%, in the most preferred case not less than 95% of 1,2-butylene oxide groups.

The ethylene oxide group (ethylene oxide groups) (A), the propylene oxide group (propylene oxide groups) (B) and the butylene oxide group (butylene oxide groups) (D) are randomly (randomly) distributed, they are distributed one after the other, or they are in the form two, three, four, five or several blocks located in any order.

According to a preferred embodiment of the invention, it is preferred that several different alkylene oxide blocks are arranged in the sequence: R ¹ , butylene oxide block, propylene oxide block, ethylene oxide block. The butylene oxide used should contain ≥80% of 1,2-butylene oxide, preferably more than 90% of 1,2-butylene oxide.

In the above general formula, X represents an alkylene group or an alkenylene group with carbon numbers from 0 to 10, preferably from 0 to 3. Preferably, the alkylene group is represented by a methylene, ethylene or propylene group.

In the prior art cited, the description of tetracarbon epoxides often does not provide any specific data. In the general case, it can be assumed that these data relate to 1,2-butylene oxide, 2,3-butylene oxide, isobutylene oxide, or a mixture of these compounds. In general, the composition can be determined by the four-carbon olefin used, as well as to some extent by the oxidation method.

In the above general formula, Y represents a sulfonate, sulfate or carboxylate group or a phosphate group.

In the above general formula, M ⁺ means a cation, in a preferred case, this cation is selected from the group: Na ⁺ , K ⁺ , Li ⁺ , NH ₄ ⁺ , H ⁺ , Mg ²⁺ and Ca ²⁺ .

Surfactants corresponding to the general formula can be obtained in a generally known manner by alkoxylation of the corresponding R ¹ -OH alcohols. In principle, such alkoxylation reactions are known to the skilled person. The specialist is also aware that by choosing the reaction conditions, in particular by choosing a catalyst, it is possible to influence the molecular weight distribution in alkoxylates.

The surfactants corresponding to the general formula are preferably obtained by alkoxylation, catalyzed by bases. In this case, alkali metal hydroxides, preferably potassium hydroxide, or alkali metal alkoxides such as sodium methylate can be added to the R ¹ -OH alcohol in the pressure reactor. Under reduced pressure (for example, less than 100 mbar) and / or at elevated temperature (30 to 150 ° C), water still contained in the mixture can be removed. After that, the alcohol is in the form of the corresponding alcoholate. An inert atmosphere is then created using an inert gas (for example, nitrogen) and alkylene oxide (alkylene oxides) is supplied in separate portions at a temperature of 60 to 180 ° C to a maximum pressure of 10 bar. According to a preferred embodiment of the reaction, alkylene oxide is first supplied at 130 ° C. During the reaction, the temperature rises to 170 ° C due to the heat of reaction generated. Moreover, in accordance with another preferred embodiment of the invention, butyleneoxy is first supplied at a temperature in the range of 135 to 145 ° C., then propylene oxide is supplied at a temperature in the range of 130 to 145 ° C. and then ethylene oxide is supplied at a temperature in the range of 125 to 145 ° C. At the end of the reaction, the catalyst can be neutralized, for example, by the addition of an acid (for example, acetic acid or phosphoric acid) and, if necessary, filtered.

However, alkoxylation of alcohols R ¹ -OH can be carried out by other methods, for example, by alkoxylation catalyzed by acids. In addition, clays from double hydroxides can be used, for example, as presented in the German patent application No. 4325237 A1, or double metal cyanide catalysts (DMC catalysts) can be used. Suitable double metal cyanide catalysts are presented, for example, in the patent application of Germany No. 10243361 A1, in particular, in the text from [0029] to [0041], and in the literature cited therein. So, for example, zinc-cobalt type catalysts can be used. To carry out the reaction, it is possible to add a catalyst to the R ¹ -OH alcohol, remove water from the mixture as described above, and react with alkylene oxides as described. Typically, no more than 1000 ppm of catalyst is used per mixture, and the catalyst used in such a minimum amount may remain in the product. Typically, the amount of catalyst may be less than 1000 ppm, for example, it may be 250 ppm or even less.

The anionic group is introduced last. In principle, this is known to the specialist. In the case of the sulfate group, for example, a reaction with sulfuric acid, with chlorosulfonic acid or with sulfur trioxide can be used in a falling film reactor, followed by neutralization. In the case of the sulfonate group, it is possible, for example, to react with propansultone followed by neutralization, with butansultone followed by neutralization, with the sodium salt of vinyl sulfonic acid or with the sodium salt of 3-chloro-2-hydroxypropanesulfonic acid. In the case of the carboxylate group, it is possible, for example, to take advantage of the oxidation of alcohol with oxygen, followed by neutralization or, accordingly, reaction with the sodium salt of chloroacetic acid.

Other surfactants

Together with the corresponding general formula of surfactants, the composition may, if necessary, also contain other surfactants. They are, for example, anionic surfactants such as alkylaryl sulfonates or olefin sulfonates (alpha olefin sulfonates or internal olefin sulfonates) and / or nonionic surfactants such as alkyl ethoxylates or alkyl polyglucosides. These other surfactants can also be represented, in particular, oligomeric or polymeric surfactants. With such polymeric additional surfactants, it is possible to successfully reduce the amount of surfactants necessary for the formation of a microemulsion. Therefore, such polymeric additional surfactants are called microemulsion activators (Mikroemulsionsbooster). Examples of such polymeric surfactants include amphiphilic block copolymers which comprise at least one hydrophilic and at least one hydrophobic block. Examples are polypropylene oxide-polyethylene oxide block copolymers, polyisobutene-polyethylene oxide block copolymers, and also comb polymers with polyethylene oxide side chains and a hydrophobic backbone, with the main chain preferably consisting of olefins or (meth) acrylates as structural units. Moreover, the term “polyethylene oxide” should include polyethylene oxide blocks containing propylene oxide structural units in accordance with the above definition. A more detailed description of such surfactants is presented in WO 2006/131541 A1.

The method of oil production

When implementing the method of oil production corresponding to the invention, an appropriate aqueous composition of surfactants corresponding to the general formula is pumped into the oil reservoir through at least one injection well and crude oil is taken through at least one production well. In this regard, it should, of course, be understood that the term "crude oil" does not refer to oil in the form of a pure phase, that is, it refers to ordinary emulsions from crude oil and water. As a rule, several injection wells and several production wells were drilled into the field.

The main effect of surfactants is aimed at reducing the surface tension between water and oil, while it is desirable that it be significantly lower than 0.1 mN / m After injecting the composition of surfactants or so-called tensid flooding, with preference being given to flooding using a Winsor type III microemulsion, water (water flooding) can be pumped into the geological formation to maintain pressure or, in the preferred case, a more viscous aqueous polymer solution, which provides a significant viscosity increase (polymer flooding). Also known are technologies in accordance with which a single exposure to surfactants is first carried out on the geological formation. Another well-known technology is represented by the injection of a solution of a surfactant and a thickening polymer, followed by the injection of a solution of a thickening polymer. The specialist knows the details of the technical carrying out of tensid flooding, water flooding and polymer flooding, and in accordance with this, he applies the appropriate technology depending on the specifics of the oil field.

To implement the method according to the invention, an aqueous composition of surfactants of the general formula is used. Together with water, these compositions may, as appropriate, contain miscible with water, or at least dispersible in water, organic or other means. Such additives serve, in particular, in order to stabilize the composition of surfactants during storage or, accordingly, during transportation to an oil field. Typically, the amount of such additional solvents should not exceed 50 wt.%, Preferably 20 wt.%. In a particularly suitable embodiment of the invention, only water is used to prepare the composition. Examples of water miscible solvents include, in particular, alcohols such as methanol, ethanol and propanol, butanol, sec-butanol, pentanol, butylene ethylene glycol, butyl diethylene glycol or butyl triethylene glycol.

In accordance with the invention, the content of the surfactants corresponding to the general formula is not less than 30 wt.% Based on the amount of all surfactants present in the composition, that is, the amount of surfactants and surfactants corresponding to the general formula, which could be added if necessary. In a preferred case, this content is at least 50 wt.%.

The mixture used in accordance with the invention can be successfully used for tensid flooding of oil-bearing formations. In particular, it is suitable for flooding with Winsor type III microemulsions (flooding in the region of existence of Winsor type III or, accordingly, in the region of existence of a bicontinuous microemulsion phase). The technology of microemulsion flooding was presented in detail above.

Along with surfactants, the compositions may also contain other components, for example, alcohols with the number of carbon atoms from four to eight and / or basic salts (the so-called "alkaline tensid flooding"). Using such additives, for example, it is possible to reduce the retention time in the geological formation. The quantitative ratio of alcohols to the total amount of surfactants is, as a rule, not less than 1: 1, however, a significant excess of alcohol may also occur. The amount of basic salts may typically reach from 0.1 mass% to 5 mass%.

The deposits where this method can be applied have, as a rule, a temperature of at least 10 ° C, for example, from 10 to 150 ° C, preferably this temperature is at least from 15 ° C to 120 ° C. The total concentration of all surfactants amounts to from 0.05 to 5 wt.%, Preferably from 0.1 to 2.5 wt.%, Based on the total weight of the aqueous composition of the surfactants. The appropriate choice of the required properties falls within the competence of a specialist, taking into account, in particular, the relationships in the oil-bearing geological formation. In this case, the specialist understands that the concentration of surfactants can change after injection into the geological formation, since the composition can be mixed with the water present in the geological formation, or since the surfactants can be sorbed by the solid surfaces of the geological formation. A serious advantage of the mixture used in accordance with the invention is that its surfactants provide a very good reduction in surface tension.

It goes without saying that it is possible or even desirable to first obtain a concentrate, which is already diluted in place to the desired concentration for injection into the geological formation. As a rule, the total concentration of surfactants in such a concentrate is from 10 to 45 wt.%.

The invention is illustrated in more detail by the following examples.

Part I. Synthesis of surfactants

General Procedure 1. Alkoxylation by catalysis with potassium hydroxide (in the case of ethylene oxide, propylene oxide and / or 1,2-butylene oxide).

In an autoclave with a volume of 2 l, an aqueous solution of potassium hydroxide with a KOH content of 50 wt.% Is added to the alkoxylated alcohol (1.0 equivalent). The amount of potassium hydroxide is 0.2 wt.% Based on the resulting reaction product. With stirring, water is removed from the mixture for 2 hours at a temperature of 100 ° C and a pressure of 20 mbar. After that, it is washed three times with nitrogen, an initial pressure of 1.3 bar is set by feeding nitrogen, and the temperature is raised to 120-130 ° C. The alkylene oxide supply is carried out so that the temperature is maintained in the range from 125 ° C to 135 ° C (for ethylene oxide) or, respectively, from 130 to 140 ° C (for propylene oxide) and, accordingly, from 135 to 145 ° C (for 1, 2-butylene oxide). Then, stirring was continued for 5 hours at a temperature of 125 to 145 ° C, washed with nitrogen, cooled to 70 ° C, and the reactor was unloaded. The crude product having the main reaction is neutralized with acetic acid. Alternatively, neutralization can also be carried out on the market with magnesium silicates, which are then filtered off. The light product is characterized by 1H NMR spectrum in deuterochloroform, gel permeation chromatography and determination of hydroxyl number, yield is calculated.

General Procedure 2. Alkoxylation in catalysis by double metal cyanide catalysts for 2,3-butylene oxide.

In a 2 liter autoclave, an alkoxylated alcohol (1.0 equivalent) at 80 ° C is mixed with a double metal cyanide catalyst (for example, it is a DMC catalyst from BASF zinc-cobalt type). To activate the catalyst, about 20 mbar is kept in vacuum at a temperature of 80 ° C for one hour. Moreover, the amount of DMC catalyst is 0.1 wt.% And even less based on the resulting reaction product. After that, it is washed three times with nitrogen, an initial pressure of about 1.3 bar is set by feeding nitrogen, and the temperature is raised to 120-130 ° C. The alkylene oxide supply is carried out so that the temperature is maintained in the range from 125 ° C to 135 ° C (for ethylene oxide) or, respectively, from 130 to 140 ° C (for propylene oxide) and, accordingly, from 135 to 145 ° C (for 2, 3-butylene oxide). Then stirring is continued for 5 hours at a temperature of from 125 to 145 ° C, washed with nitrogen, cooled to 70 ° C and the reactor is unloaded. The light product is characterized by 1 H NMR in deuterochloroform, gel permeation chromatography and determination of the hydroxyl number, yield is calculated.

General procedure 3. Sulfation by the action of chlorosulfonic acid.

In a 1-L round-bottom flask, dissolve sulfated alkyl alkoxylate (1.0 equivalent) in one and a half times the amount of dichloromethane (based on mass) and cool to a temperature of 5 to 10 ° C. Then, chlorosulfonic acid (1.1 equivalents) is added at such a rate that the temperature does not exceed 10 ° C. The mixture was allowed to warm to room temperature and stirred for 4 hours at a temperature in a stream of nitrogen, then the resulting reaction mixture at a temperature not exceeding 15 ° C was added dropwise to an aqueous solution of sodium hydroxide, the volume of which was half that. The amount of sodium hydroxide is calculated so that a slight excess is obtained based on the chlorosulfonic acid used. The final pH is from about 9 to 10. Dichloromethane is removed under slight vacuum in a rotary evaporator at a temperature of not more than 50 ° C.

The product is characterized by 1H NMR spectrum data and the water content in the solution is determined (about 70%).

For the synthesis, the following alcohols were used.

Alcohol Description Iso-C ₁₇ Heptadecyl alcohol of isomeric structure; oxoalcohol obtained by hydroformylation of isohexadecene, which is formed by tetramerization of butene. The average degree of branching of alcohol is 3.1. C ₁₆ / C ₁₈ A commercially available mixture of alcohols consisting of linear hexadecyl and octadecyl alcohol. C ₁₆ - Gerbe alcohol Commercially Accepted C ₁₆ is an alcohol obtained by the Gerbe reaction (2-hexyldecan-1-ol)

Technical Application Experience

The obtained surfactants were investigated in the experiments presented below to assess their suitability for tertiary oil production.

Description of determination methods

Determination of solubilization parameter (SP *)

a) Principles for determining the parameter

The surface tension between water and oil is determined in a known manner according to the measurement of the solubilization parameter SP *. The determination of surface tension through the determination of the solubilization parameter SP * is a method adopted by experts to approximately determine the surface tension. The solubilization parameter SP * shows how many milliliters of oil per milliliter of surfactant used was dissolved in the microemulsion (Winsor type III). Based on this, the surface tension c can be calculated using the empirical formula σ≈0.3 / (SP *) ² provided that water and oil were taken in equal volumes (C. Huh, J. Coll. Interf. Sc., T .71, No. 2 (1979)).

b) Methodology of the experiment

To determine SP *, 20 ml of oil and 20 ml of water are poured into a 100 ml graduated cylinder with a magnetic stirrer. The corresponding surfactants in various concentrations are also added here. After that, the temperature is gradually increased from 20 to 90 ° C and visually determine in which temperature range the microemulsion is formed.

The formation of a microemulsion can be determined visually or also by measuring transmittance. A three-phase system is formed where the upper phase is composed of oil, the middle phase is a microemulsion and the lower phase is water. If the upper and lower phases have the same volume and no longer change within 12 hours, then this means that the optimum temperature (T _opt ) of the microemulsion is found. The volume of the middle phase is determined. The volume of added surfactant is subtracted from this volume. The resulting value is then divided by 2. This volume is now divided by the volume of added surfactant. The result of the division is the solubilization parameter SP *.

The type of oil and water used to determine SP * is determined by the system under study. You can use both the oil itself and the substance modeling it, for example, dean. Both pure water and salt water can be used as water, this is necessary in order to better simulate the conditions existing in the oil-bearing geological formation. The composition of the aqueous phase can be set, for example, in accordance with the composition of the water in a particular oil field.

Data on the used aqueous phase and oil phase will be given later in the description of specific experiments.

Test results

Butyl diethylene glycol is added to a mixture of decane and sodium chloride solution in a 1: 1 ratio. Butyl diethylene glycol (BDG) is an additional solvent and therefore it is not taken into account when calculating the SP * values. To this composition is added a surfactant mixture consisting of three parts of alkyl alkoxysulfate and one part of dodecylbenzenesulfonate (Lutensit A-LBN 50 manufactured by BASF). The total concentration of surfactants is indicated in percent by weight of the total volume.

In another experiment, butyldiethylene glycol was added to a mixture of decane and sodium chloride solution in a 1: 1 ratio. Butyl diethylene glycol is an additional solvent and therefore is not taken into account when calculating the SP * values. A surfactant mixture consisting of three parts of an alkyl alkoxysulfate and one part of a secondary alkanesulfonate (Hostapur SAS 60 manufactured by Clariant) is added to this composition. The total concentration of surfactants is indicated as a percentage of the mass of the aqueous phase.

In addition to this, butyldiethylene glycol is added to a mixture of South German crude oil (API 33 °) and a sodium chloride solution in a 1: 1 ratio. Butyl diethylene glycol is an additional solvent and therefore is not taken into account when calculating the SP * values. To this composition is added a surfactant mixture consisting of three parts of alkyl alkoxysulfate and one part of dodecylbenzenesulfonate (Lutensit A-LBN 50 manufactured by BASF). The total concentration of surfactants is indicated in percent by weight of the total volume.

In two other experiments, a 1: 1 mixture of South German crude oil (API 33 °) and sodium chloride solution and, accordingly, a 1: 1 mixture of Canadian crude oil (API 14 °) and sodium chloride solution were prepared, butyl diethylene glycol was added to each of these mixtures. Butyl diethylene glycol is an additional solvent and therefore is not taken into account when calculating the SP * values. A surfactant mixture consisting of three parts of alkyl alkoxysulfate and one part of secondary alkanesulfonate (Hostapur SAS 60 manufactured by Clariant) is added to each of these formulations. The total concentration of surfactants in each case is indicated as a percentage of the mass of the aqueous phase.

The results obtained on surface-active substances based on linear and, accordingly, branched alcohols are given in tables 1 to 7.

Table 1 Linear alcohol based surfactants with sixteen and eighteen carbon atoms Example Alkyl-AO-SO ₄ Na: C ₁₂ H ₂₅ -C ₆ H ₄ -SO ₃ Na = 3: 1 Surfactant [%] BDG [%] NaCl [%] T T _opt [° C] SP * σ [mN / m] V1 C ₁₆ C ₁₈ -7PO-SO ₄ Na 2,5 2 5 48 13.3 0.0017 V2 C ₁₆ C ₁₈ -7PO-SO ₄ Na 2,5 2 four 60 17.8 0,0009 V3 C ₁₆ C ₁₈ -9 PO-SO ₄ Na 2,5 2 5 52 15,5 0.0012 V4 C ₁₆ C ₁₈ -9 PO-SO ₄ Na 2,5 2 four 67 17.8 0,0009 5 C ₁₆ C ₁₈ -2 “1,2-BuO” -PO-SO ₄ Na 2,5 2 5 47 16 0.0012 6 C ₁₆ C ₁₈ -2 “1,2-BuO” -7PO-SO ₄ Na 2,5 2 four 65 16.5 0.0011 V7 C ₁₆ C _l8 -7PO-2 “1,2-BuO” -SO ₄ Na 2,5 2 four 46 11.8 0.0022 V8 C ₁₆ C ₁₈ -7PO-2 "1,2-BuO" -SO ₄ Na 2,5 2 3 68 14.3 0.0015 V9 C ₁₆ C ₁₈ -9 PO-SO ₄ Na 1.25 2 5 52 fourteen 0.0015 V10 C ₁₆ C ₁₈ -9 PO-SO ₄ Na 1.25 2 four 67 13 0.0018 eleven C ₁₆ C ₁₈ -2 “1,2-BuO” -7PO-SO ₄ Na 1.25 2 3.35 72 fifteen 0.0013 V12 C ₁₆ C ₁₈ -2 “2,3-BuO” -7PO-SO ₄ Na 1.25 2 4,5 74 8 0.0047 13 C ₁₆ C ₁₈ -3 "1,2-BuO" 7PO-SO ₄ Na 1.25 2 3 67 23.5 0,0005 fourteen C ₁₆ C ₁₈ -5 "1,2-BuO" -7PO-SO ₄ Na 1.25 2 2 77 34.5 0,0003 fifteen C ₁₆ C ₁₈ -5 "1,2-BuO" -7PO-SO ₄ Na 1.25 2 2.15 71 35.5 0,0002 16 C ₁₆ C ₁₈ -5 "1,2-BuO" -7PO-SO ₄ Na 1.25 2 2,5 49 30.5 0,0003 AO - alkylene oxide structural element
The experiments with the designation V are examples of comparison.

As shown in Table VI of Examples VI and V3 or, respectively, in Comparative Examples V2 and VI4, differences in SP * between C ₁₆ C ₁₈ -7PO-SO ₄ Na and C ₁₆ C ₁₈ -9PO-SO ₄ Na are small (EO and PO - ethylene oxide and propylene oxide structural units). In addition, it should be borne in mind that the comparison should be carried out at the same values of T _opt in order to exclude the influence of temperature. In surfactants with non-ionic elements, the influence of temperature can be quite significant.

If C ₁₆ C ₁₈ alkoxysulfates containing butylene oxide groups (BuO) are used, unexpected results are manifested. Examples 5 and 6 show that the insertion of two structural units based on 1,2-butylene oxide between the residue of a fatty alcohol with sixteen and eighteen carbon atoms and seven propylene oxide structural units (7PO) leads to a surprisingly stable value of SP * = 16, which does not depend on temperature equal to 47 ° C or 62 ° C. A similar picture is observed with a decrease in the total content of surfactants. In Example 11, at a temperature of 72 ° C, the SP * value is 15. Compounds containing only propylene oxide structural units, at the same degree of alkoxylation, show more serious deviations (V3 and V4) or, when the total content of surfactants decreases, the SP * values fall more noticeable (V9 and V10).

The incorporation of 1,2-butylene oxide structural units between the propylene oxide block and the sulfate group, as follows from the indicators in the comparison examples V7 and V8, is in contrast unfavorable. The value of SP * in this case lies at a slightly lower level and shows stronger fluctuations with temperature.

The use of 2,3-butylene oxide is significantly worse. As example V12 shows, the value of SP * (SP * = 8) is almost two times lower and therefore worse than in the case of using alkyl propoxysulfates with the same degree of alkoxylation (V9). It is unexpectedly discovered that not only the number of carbon atoms, but also their spatial arrangement have a great influence on the ability of surface-active substances to reduce surface tension. An unfavorable location, as in 2,3-butylene oxide, even has a negative effect and leads to poorer performance than the corresponding surfactants obtained without the participation of alkylene oxide with four carbon atoms. In US patent No. 3890239 or No. 4448697 this is not described.

Interestingly, a stepwise improvement is achieved when the content of 1,2-butylene oxide structural units reaches three or more with linear alcohol with sixteen and eighteen carbon atoms. In Example 13, the incorporation of three such structural units leads to an increase in SP * to 23.5. This value can be increased even further by introducing five such structural units (examples 14 to 16). In this case, the SP * value becomes even greater than 30

table 2 Branched isoheptadecyl alcohol surfactants Example Alkyl-AO-SO ₄ Na: C ₁₂ H ₂₅ C ₆ H-SO ₃ Na = 3: 1 Surfactant [%] BDG [%] NaCl [%] T _opt [° C] SP * σ [MMMN / m] V1 iso-30-C ₁₇ -7PO-SO ₄ Na 1.25 2 four 77.5 10.5 0.0027 2 iso-C ₁₇ 7 «1,2-BuO» -SO ₄ Na 1.25 2 one 82.5 32,5 0,0003 V3 iso-C ₁₇ -14PO-SO ₄ Na 1.25 2 4.4 77 6.5 0.0071 four iso-C ₁₇ 7 «1,2-BuO» -SO ₄ Na 1.25 2 1.65 74.5 17 0.0010 5 iso-C ₁₇ 7 «1,2-BuO» -7PO-SO ₄ Na 1.25 2 2,5 67.5 31.5 0,0003

A similar picture is presented in Table 2. In this case, branched isoheptadecyl alcohol-based alkyl alkoxysulfates were used in order to demonstrate that this is an effect that is not only manifested on linear alcohols.

Comparison example V1 and example 2 show very convincingly that for surfactants with the same degree of alkoxylation, the use of 1,2-butylene oxide instead of propylene oxide provides undeniable advantages. At the same temperature, the value of SP * increases three times. Also, the location of 1,2-butylene oxide structural units directly at the alkyl part (as follows from the data of examples 5 and 6) provides lower surface tension values than their other location, as in example 4.

Table 3 Surfactants based on branched C ₁₆ alcohol Gerbe in comparison with surfactants based on C ₁₆ / C ₁₈ alcohols Example Alkyl-AO-SO ₄ Na: C ₁₂ H ₂₅ C ₆ H-SO ₃ Na = 3: 1 Surfactant [%] BDG [%] NaCl [%] T _opt [° C] SP * σ [mN / m] V1 C ₁₆ C ₁₈ -9 PO-SO ₄ Na 1.25 2 four 67 13 0.0018 2 C ₁₆ C ₁₈ -2 “1,2-BuO” -7PO-SO ₄ Na 1.25 2 3.35 72 fifteen 0.0013 3 C ₁₆ -her6e-2 "1,2-BuO" -7PO-SO ₄ Na 1.25 2 2.85 68 27.5 0,0004 four With ₁₆ -Herbe-2 "1,2-BuO" -7PO-S0 ₄ Na 1.25 2 3 64 23.5 0,0005 5 C ₁₆ C ₁₈ -3 "1,2-BuO" -7PO-SO ₄ Na 1.25 2 3 67 23.5 0,0005 6 With ₁₆ -Herbe-7 "1,2-BuO" -7PO-10EO-SO ₄ Na 0.40 2 4.5 73 31 0,0003 V7 C ₁₆ -Herbe-7PO-SO ₄ Na 1.25 2 5 70 6 0.0083 V8 C ₁₆ -Herbe-9PO-SO ₄ Na 1.25 2 four 71 9 0.0037 V9 C ₁₆ -Herbe-6PO-SO ₄ Na 1.25 2 5 64 5 0.0120 V10 C ₁₆ C ₁₈ -6 PO-SO ₄ Na 1.25 2 5 64 10 0.0030 eleven With ₁₆ -Herbe-1 "1,2-BuO" -7РО-SO ₄ Na 1.25 2 3.3 73 10.25 0.0029

Table 3 shows that in this case a similar picture is observed. If a linear alcohol-based surfactant includes more than two structural units based on 1,2-butylene oxide, the result is a noticeable increase in the SP * value and a related decrease in surface tension. Example 2 in comparison with examples 3 and 4 shows the difference between a linear alcohol-based surfactant with sixteen and eighteen carbon atoms and a branched alcohol surfactant based on a branched alcohol with 16 carbon atoms. In the case of a surfactant based on a product obtained by the Gerbe reaction, already upon incorporation of two structural units from 1,2-butylene oxide, a significantly better SP * is achieved than on the basis of a linear alcohol with a similar chain length. However, with the incorporation of an even greater amount of 1,2-butylene oxide and in the case of a linear alcohol, it is possible, as Example 5 shows, to obtain approximately the same level of SP * similar to Example 4.

Example 6 shows that by incorporating ten ethylene oxide structural units (EO) between the sulfate group and the propylene oxide block, the additional hydrophobicity from the block of seven butylene oxide structural units can be almost completely compensated, and then it becomes possible to compare with comparison example VI under similar conditions (similar salt content and the same optimal temperature T _opt ).

Without incorporation of 1,2-butylene oxide, a surfactant with average values is obtained, as follows from the comparison examples of V7 and V8. Example 11 shows that incorporation of one equivalent of 1,2-butylene oxide only leads to a certain improvement in SP *. Significant improvement is achieved only by incorporating two equivalents of 1,2-butylene oxide into a surfactant based on the Hebrew alcohol with sixteen carbon atoms (Example 3).

Table 4 South German Crude Oil Experiments Example Alkyl-AO-SO ₄ Na: C ₁₂ H ₂₅ C ₆ H-SO ₃ Na = 3: 1 Surfactant [%] BDG [%] NaCl [%] T _opt [° C] SP * σ [mN / m] V1 C ₁₆ C _l8 -9PO-SO ₄ Na 0.8 2 5 34.5 9.7 0.0032 2 C ₁₆ C ₁₈ -3 "1,2-BuO" -7PO-SO4Na 0.8 2 3,5 31 15.9 0.0012 V3 C ₁₆ -Herbe-9PO-SO ₄ Na 0.8 2 5.1 34 5.8 0.0089 four With ₁₆ -Herbe-2 "1,2-BuO" -7PO-SO ₄ Na 0.8 2 3,5 34 fifteen 0.0013

As Table 4 shows, a picture is observed with crude oil that is almost identical to that obtained in experiments with the oil modeling dean. The comparison example V1 shows significantly lower values of SP * and therefore has a higher surface tension than the surface-active substance containing butylene oxide structural elements of example 2 at similar temperatures. Comparative Example V3 and Example 4 in the same manner show the advantage of 1,2-butylene oxide.

Table 5 Experiments with a dean at a similar temperature and salinity Example Alkyl-AO-SO ₄ Na: C ₁₂ H ₂₅ C ₆ H _- SO ₃ Na = 3: 1 Surfactant [%] BDG [%] NaCl [%] T _opt [° C] SP * σ [mN / m] V1 C ₁₆ C ₁₈ -7PO-0,1EO-SO ₄ Na 0.4 2 4.7 59.9 18.3 0,0009 2 C ₁₆ C ₁₈ -3 "1,2-BuO" -7PO-10EO-SO ₄ Na 0.4 2 4.7 64.8 37 0,0002

Aqueous solutions of surfactants in a mixture with butyldiglycol (BDH) are transparent under optimal conditions (salinity and T _opt ) and, when added to oil, they form a three-phase system (Winsor type III). As shown in table 5, the optimal conditions (salinity and T _opt ) are almost identical. When the degree of alkoxylation is correctly set, a surfactant is obtained, as shown in Example 2, that has a hydrophilic-hydrophobic balance similar to the hydrophilic-hydrophobic balance of the surfactant according to Comparative Example V1. However, the SP * value of Example 2 is much larger. In accordance with this below and surface tension.

Table 6 South German oil test (API 33 °) at similar temperature and salinity Example Alkyl-AO-SO ₄ : Hostgapur SAS 60 = 3: 1 Surfactant [%] BDG [%] NaCl [%] T _opt [° C] SP * σ [MN / m] VI C ₁₆ C ₁₈ -7PO-0,1EO-SO ₄ Na 0.4 2 3,5 73 24.5 0,0005 2 C ₁₆ C ₁₈ -7 "1,2-BuO" -7PO-10EO-SO ₄ -Na 0.4 2 3,5 78.5 37 0,0002

Aqueous solutions of surfactants in a mixture with butyldiglycol (BDG) under optimal conditions (salinity and T _opt ) are transparent and when oil is added they form a three-phase system (Winsor type III). As shown in table 6, the optimal conditions (salinity and T _opt ) are almost identical. When the degree of alkoxylation is correctly set, a surfactant is obtained, as shown in Example 2, that has a hydrophilic-hydrophobic balance similar to the hydrophilic-hydrophobic balance of the surfactant according to Comparative Example V1. However, the SP * value of Example 2 is much larger. In accordance with this below and surface tension.

Table 7 Canadian oil test (API 14 °) at similar temperature and salinity Example Alkyl-AO-SO ₄ : Hostgapur SAS 60 = 3: 1 Surfactant [%] BDG [%] NaCl [%] T _opt [° C] SP * σ [MN / m] V1 C ₁₆ C ₁₈ -7PO-0,1EO-SO ₄ Na 0.4 2 7 55 12 0.0021 2 C ₁₆ C ₁₈ -7 “1,2-BuO” -7PO-10EO-SO ₄ -NaCi ₆ C _l8 -7 “1,2-BuO” -7PO-8EO-S0 ₄ -Na = 2 0.4 2 7 57 19.5 0,0008

Aqueous solutions of surfactants in a mixture with butyldiglycol (BDG) under optimal conditions (salinity and T _opt ) are transparent and when oil is added they form a three-phase system (Winsor type III). As shown in table 7, the optimal conditions (salinity and T _opt ) are almost identical. When the degree of alkoxylation is correctly set, a surfactant is obtained, as shown in Example 2, which has a hydrophilic-hydrophobic balance similar to the hydrophilic-hydrophobic balance of the surfactant according to Comparative Example VI. However, the SP * value of Example 2 is much larger. In accordance with this below and surface tension.

Claims (7)

1. A method of oil production by water flooding with a Vinsor type III microemulsion, in which an aqueous composition of surface-active substances is injected through at least one injection well into an oil field to reduce the surface tension between oil and water to less than 0.1 mN / m containing at least one ionic surfactant, and crude oil is extracted from the field through at least one production well, characterized in that the aqueous composition of the surfactant is used x substances containing at least one surfactant of the general formula
R ¹ -O- (D) _n - (B) _m - (A) _l -XY ^- M ⁺ ,
Where
R ¹ means a linear or branched, saturated or unsaturated aliphatic and / or aromatic hydrocarbon residue from 8 to 30 carbon atoms,
And means an ethyleneoxy group,
B means propyleneoxy group, and
D means butyleneoxy group,
l means a number from 0 to 99,
m means a number from 0 to 99, and
n means a number from 1 to 99,
X is an alkyl or alkylene group from 0 to 10 carbon atoms,
M ⁺ means a cation, and Y ^{- is} selected from the group: sulfate groups, sulfonate groups, carboxylate groups and phosphate groups, while
groups A, B and D may have a statistical or alternating distribution, or they may be present in the form of two, three, four or several blocks in any sequence, the sum l + m + n lies in the range from 3 to 99 and the content is 1.2- butyleneoxy groups based on the total number of butyleneoxy groups is at least 80%. 2. The method according to p. 1, where the sum l + m + n lies in the range from 5 to 50. 3. The method according to p. 1, where the content of 1,2-butyleneoxy groups based on the total number of butyleneoxy groups is at least 90%. 4. The method according to claim 1, where the surfactant of the General formula contains from two to fifteen 1,2-butyleneoxy structural units. 5. The method according to p. 1, where the concentration of all surfactants together is from 0.05 to 5 wt.% Based on the total amount of the aqueous composition of surfactants. 6. The method according to one of paragraphs. from 1 to 5, where
m means a number from 5 to 9,
n means a number from 2 to 10, and
Y ^- selected from the group: sulfate groups, sulfonate groups and carboxylate groups, while
groups A, B and D are more than 80% in the form of blocks in the sequence D, B, A, starting from R ¹ , the sum l + m + n lies in the range from 7 to 49, and the content of 1,2-butyleneoxy groups based on the total number of butyleneoxy groups in the molecule is at least 90%. 7. The method according to claim 6, where R ¹ means a linear hydrocarbon residue derived from a fatty alcohol with sixteen or eighteen carbon atoms, and n means a number from 3 to 10.