KR20130016266A - Method for extracting mineral oil using surfactants based on butylene oxide-containing alkyl alkoxylates - Google Patents

Abstract

의 1종 이상의 이온성 계면활성제를 포함하는 수성 계면활성제 제제를 주입 시추공을 통해 광유 광상으로 주입하고, 원유를 제조 시추공을 통해 광상으로부터 배출시키는 윈저 Ⅲ형 마이크로에멀션 플로딩에 의한 광유 추출 방법에 관한 것이다. 본 발명은 추가로 상기 일반식의 이온성 계면활성제에 관한 것이다.The present invention is a general formula

A method for extracting mineral oil by Windsor III type microemulsion flotation in which an aqueous surfactant formulation comprising at least one ionic surfactant is injected into a mineral oil deposit through an injection borehole and the crude oil is discharged from the deposit via a borehole. will be. The invention further relates to an ionic surfactant of the above general formula.

Description

METHODS FOR EXTRACTING MINERAL OIL USING SURFACTANTS BASED ON BUTYLENE OXIDE-CONTAINING ALKYL ALKOXYLATES}

의 1종 이상의 이온성 계면활성제를 포함하는 수성 계면활성제 제제를 주입 시추공을 통해 광유 광상으로 주입하고, 원유를 제조 시추공을 통해 광상으로부터 배출시키는 윈저(Winsor) Ⅲ형 마이크로에멀션 플로딩에 의한 광유 추출 방법에 관한 것이다. 본 발명은 추가로 상기 일반식의 이온성 계면활성제 및 이의 제조 방법에 관한 것이다.The present invention is a general formula

Mineral oil extraction by injecting an aqueous surfactant formulation comprising at least one ionic surfactant into a mineral oil deposit via an injection borehole and discharging crude oil from the deposit via a production borehole to extract mineral oil by Winsor III microemulsion floating It is about a method. The present invention further relates to ionic surfactants of the above general formula and methods for their preparation.

In natural mineral oil deposits, mineral oil is present in the cavities of porous reservoir rocks stored on the surface of the earth by an impermeable upper layer. The cavity may be a very fine cavity, capillary, pore or the like. Fine pore necks may, for example, have a diameter of only about 1 μm. Mineral oils, as well as a fraction of natural gas, as well as deposits contain water in some salt content.

In mineral oil extraction, there is generally a difference between primary, secondary and tertiary extraction. In the primary extraction, the mineral oil flows spontaneously through the borehole to the surface due to autogenous pressure of the deposit after initiation of the drilling of the deposit.

After the primary extraction, a secondary extraction is thus used. In secondary extraction, in addition to the boreholes which function in the extraction of mineral oil, the so-called drilling, additional boreholes are drilled into the mineral oil holding strata. Water is injected into the deposit through these so-called injection boreholes to maintain pressure or increase it again. As a result of the injection of water, the mineral oil is forced slowly into the stratum through the cavity starting from the injection drilling in the direction of the manufacturing drilling. However, this only works while the cavity is completely filled with oil and the more viscous oil is pushed forward by the water. As soon as the mobile water breaks through the cavity, it then flows in the smallest resistance path, ie through the formed channel, and no longer pushes the oil forward.

By primary and secondary extraction, amounts of generally only about 30 to 35% of the mineral oil present in the deposit can be extracted.

It is known that mineral oil yield can be further improved as a means for tertiary oil extraction. An overview of tertiary oil extraction can be found, for example, in "Journal of Petroleum Science of Engineering 19 (1998)", pages 265-280. Tertiary oil extraction is, for example, a thermal method in which hot water or steam is injected into the deposit. This reduces the viscosity of the oil. The flow medium used may likewise be a gas such as CO ₂ or nitrogen.

Tertiary mineral oil extraction also includes methods in which suitable chemicals are used as an aid to oil extraction. This can be used to extract the mineral oil which affects the situation on the end of the water flow and as a result is also firmly fixed in the rock strata.

Viscosity and capillary pressure affect the mineral oil trapped in the pores of the deposit rock at the end of the secondary extraction, so the ratio of these two forces to each other is determined by microscopic oil separation. The action of these forces is described by dimensionless parameters, the so-called parent values. This is the ratio of the viscosity force (velocity × viscosity of the applied phase) to capillary pressure (interface tension between oil and water × wetness of rock):

Where μ is the viscosity of the fluid flow mineral oil, υ is the Darcy velocity (flow per unit area), σ is the interfacial tension between the liquid flow mineral oil and the mineral oil, and θ is the contact angle between the mineral oil and the rock (C. Melrose , CF Brandner, J. Canadian Petr. Techn. 58, Oct-Dec., 1974). The larger the capillary value, the greater the mobility of the oil and thus also the greater the degree of oil removal.

It is known that the capillary value for the end of secondary mineral oil extraction is in the range of about 10 ⁻⁶ , and it is necessary to increase the capillary value from about 10 ⁻³ to 10 ⁻² to fluidize additional mineral oil.

For this purpose, it is possible to carry out certain forms of floating methods known as Windsor III type microemulsion floating. In Windsor III microemulsion flotation, the injected surfactant must form a Windsor III microemulsion with an aqueous phase and an oil phase present in the deposit. Windsor III microemulsions are not particularly emulsions with small droplets, but rather liquid mixtures of thermodynamically stable water, oils and surfactants. Three advantages thereof are as follows.

A very low interfacial tension of zero between the mineral oil and the water phase is thus achieved,

It generally has a very low viscosity and as a result is not trapped in the porous matrix,

It is formed by even the smallest energy inflow and can remain stable over a finite long period of time (conventional emulsions, on the contrary, require high shear forces, which do not mainly occur in reservoirs, but are only dynamically stabilized).

Windsor III microemulsions are in equilibrium with excess water and excess oil. Under these conditions of microemulsion formation, the surfactant covers the oil-water interface and lowers the interfacial tension (σ) to a value (ultra low interfacial tension), more preferably less than 10 ⁻² mN / m. To achieve optimal results, the ratio of microemulsions in water-microemulsion-oil systems with defined amounts of surfactants is essentially maximum because this allows lower interfacial tension to be achieved.

In this way, it is possible to change the shape of the oil droplets (the interfacial tension between oil and water is reduced to the extent that the smallest interfacial state is no longer preferred and the spherical form is no longer desirable), which is caused by the capillary Can be forced through the hole.

When all oil-water interfaces are covered by surfactants, in the presence of excess surfactant, a Windsor III type microemulsion is formed. Thus, this constitutes a reservoir for the surfactant which generates very low interfacial tension between the oil phase and the water phase. With the low viscosity Windsor III type microemulsion, it also migrates from the porous deposit rock in the floating process (the emulsion can, in turn, be trapped in the porous matrix and block deposits). When a Windsor III microemulsion encounters an oil-water interface while not yet covered with a surfactant, the surfactant from the microemulsion can significantly lower the interfacial tension of this new interface and, for example, deform the oil droplets. By flowing oil.

The oil droplets may subsequently be combined into a continuous oil bank. This has two advantages:

First, as the continuous oil bank evolves through the new porous rock, oil droplets present therein can coalesce with the bank.

In addition, the combination of oil droplets that produce the oil banks significantly reduces the oil-water interface and thus releases surfactants that are no longer needed. The released surfactant can then flow the oil droplets remaining in the strata, as described above.

Windsor III type microemulsion flotation is consequently an exceptionally efficient process and requires much less surfactant compared to the emulsion flotation process. In microemulsion flotation, surfactants are typically optionally injected with co-solvents and / or basic salts (optionally in the presence of a chelating agent). Subsequently, a solution of the thickening polymer is injected for mobility control. A further variant is the injection of a mixture of thickening polymer and surfactant, co-solvent and / or basic salt (optionally with a chelating agent), followed by a solution of thickening polymer for mobility control. Such solutions should generally be clear to prevent containment of the reservoir.

The requirements for surfactants for tertiary mineral oil extraction differ significantly from the requirements for surfactants for other uses: Suitable surfactants for tertiary oil extraction are the interfacial tension between water and oil (typically approximately 20 mN / m ) Should be reduced to particularly low values of less than 10 ⁻² mN / m to allow sufficient flow of mineral oil. This should be done in the presence of a high salt content of water, more particularly in the presence of a high proportion of calcium and / or magnesium ions, at conventional deposit temperatures of approximately 15 ° C. to 130 ° C .; The surfactant should thus also be soluble in deposits with high salt content.

In order to meet these requirements, there have already been frequent proposals of mixtures of surfactants, in particular mixtures of anionic and nonionic surfactants.

US 3,890,239 discloses organic sulfonates with alkyl alkoxylates of the type C ₈ -C ₂₀ -AO-H (AO = alkylene oxide having from 2 to 6 carbon atoms) and C ₈ -C ₂₀ -AO-sulfate Or combinations with anionic surfactants of the C ₈ -C ₂₀ -AO-sulfonate type. The details of the alkylene oxides remain very general only in the context of the disclosure of US 3,890,239. However, there are only examples that include EO exclusively.

US 4,448,697 claims the use of alkyl alkoxylates of the type C ₁ -C _6- (AO) _1-40 -EO ≧ ₁₀ -H in combination with anionic surfactants. AO may be 1,2-butylene oxide or 2,3-butylene oxide.

US 4,460,481 describes surfactants of the alkylaryl alkoxy sulfate or sulfonate type. The alkylene oxide can be ethylene oxide, propylene oxide or butylene oxide. There is a condition that ethylene oxide constitutes most alkylene oxides. There is no more detailed description of butylene oxide.

Thus, the parameters of use, such as the type, concentration and mixing ratio of the surfactants used with respect to each other, are adjusted by the person skilled in the art according to the conditions present in the desired oil strata (eg temperature and salt content).

As described above, mineral oil production is proportional to the capillary value. The lower the interfacial tension between oil and water, the greater it is. The higher the average number of carbon atoms in crude oil, the more difficult it is to achieve low interfacial tension. Suitable surfactants for low interfacial tension are those having long alkyl radicals. The longer the alkyl radical, the better the interfacial tension can be reduced. However, the availability of such compounds is very limited.

It is therefore an object of the present invention to provide an improved process for extracting surfactants and tertiary mineral oils which are particularly effective for the use of surfactant flotation.

Thus, an aqueous surfactant formulation comprising at least one ionic surfactant is injected into the mineral oil deposit via at least one injection borehole and the interface tension between oil and water is less than 0.1 mN / m, preferably 0.05 reducing to less than mN / m, more preferably less than 0.01 mN / m, crude oil is discharged from the deposit through one or more preparatory boreholes, and the surfactant formulation comprises one or more surfactants of A tertiary mineral oil extraction method by Windsor III type microemulsion floating is provided, comprising:

[Wherein,

R ¹ is a linear or branched, saturated or unsaturated, aliphatic and / or aromatic hydrocarbon radical having 8 to 30 carbon atoms,

A is ethyleneoxy,

B is propyleneoxy,

D is butyleneoxy,

l is 0 to 99,

m is 0 to 99,

n is from 1 to 99,

X is an alkyl or alkylene group having 0 to 10 carbon atoms,

M ⁺ is a cation,

Y ⁻ is selected from the group of sulfate groups, sulfonate groups, carboxylate groups and phosphate groups,

The A, B and D groups can be distributed randomly, alternately or in any order in the form of 2, 3, 4 or more blocks, the sum of l + m + n ranges from 3 to 99, 1, The proportion of 2-butylene oxide is at least 80% based on the total amount of butylene oxide].

Further provided is a surfactant mixture for mineral oil extraction comprising at least one ionic surfactant of the general formula defined above.

In connection with the present invention, the following should be described in detail:

In the above-described process according to the invention for mineral oil extraction by Windsor III type microemulsion floating, an aqueous surfactant formulation comprising at least one surfactant of the above general formula is used. In addition, it may include additional surfactants and / or other components.

In the process according to the invention for tertiary mineral oil extraction by Windsor III type microemulsion flotation, the use of the surfactant of the invention results in an interfacial tension between oil and water of less than 0.1 mN / m, preferably 0.05 mN / to a value of less than m, more preferably less than 0.01 mN / m. The interfacial tension between oil and water is thus a value in the range 0.1 mN / m to 0.0001 mN / m, preferably in the range 0.05 mN / m to 0.0001 mN / m, more preferably 0.01 mN / m to 0.0001 mN /. Decrease to a value in the range m.

로 포함될 수 있다. 제조의 결과로서, 또한 상기 일반식의 복수의 상이한 계면활성제가 계면활성제 제제 내에 존재할 수 있다. One or more surfactants are of the general formula

It may be included as. As a result of the preparation, a plurality of different surfactants of the above general formula may also be present in the surfactant formulation.

R ¹ radical is a straight or branched chain aliphatic and / or aromatic hydrocarbon radical having 8 to 30 carbon atoms, preferably 9 to 30 carbon atoms, more preferably 10 to 28 carbon atoms.

In a particularly preferred embodiment of the invention, the R ¹ radical is iso-C ₁₇ H ₃₅ , a commercial fatty alcohol mixture consisting of linear C ₁₆ H ₃₃ and C ₁₈ H ₃₇ , or a commercially available C ₁₆ Guerbet. Derived from alcohol 2-hexyldecane-1-ol or commercially available C ₂₄ gerbe alcohol 2-decyltetradecanol or from commercially available C ₂₈ gerbe alcohol 2-dodecylhexadecanol.

More preferably, n = 3 to 10 in the linear alcohol, m = 5 to 9, n = 2 to 10 and m = 5 to 9 in the branched alcohol. It is preferred herein that in each case D is greater than 80% 1,2-butylene oxide and the alkylene oxide has the order of D-B-A starting with alcohol. Alkylene oxides are arranged in blocks to greater than 90%.

Particular preference is given to linear or branched aliphatic hydrocarbon radicals, especially linear or branched aliphatic hydrocarbon radicals having 10 to 28 carbon atoms.

Branched aliphatic hydrocarbon radicals generally have a branching degree of 0.1 to 5.5, preferably 1 to 3.5. The term "branch degree" is defined herein in a manner known in principle as the number of methyl groups in an alcohol molecule-1. The mean branching is the statistical mean of the branching of all the molecules in the sample.

In the above formula, A means ethyleneoxy. B means propyleneoxy and D means butyleneoxy.

In the general formula (I) defined above, m and n are each an integer. However, it is clear to one skilled in the art that this definition in the field of polyalkoxylates is in each case the definition of a single surfactant. In the presence of a surfactant mixture or surfactant formulation comprising a plurality of surfactants of the above formulas, the numbers I, m and n are the average values across all molecules of the surfactant, respectively, because ethylene oxide and / or propylene This is because alkoxylation of alcohols with oxides and / or butylene oxides in each case provides a specific distribution of chain lengths. This distribution can be described in a manner known in principle by the polydispersity (D). D = M _w / M _n is the quotient of the weight average molar mass and the number average molar mass. Polydispersity can be determined by methods known to those skilled in the art, for example by gel permeation chromatography.

In the above general formula, l is 0 to 99, preferably 1 to 40, more preferably 1 to 20.

In the above general formula, m is 0 to 99, preferably 1 to 20, more preferably 5 to 9.

In the general formula, n is 1 to 99, preferably 2 to 30, more preferably 2 to 10.

According to the invention, the sum of l + m + n is a number in the range from 3 to 99, preferably in the range from 5 to 50, more preferably in the range from 8 to 39.

According to the present invention, the proportion of 1,2-butyleneoxy is 80% or more, preferably 85% or more, preferably 85% or more, based on the total amount of butyleneoxy (0). 90% or more, more preferably 95% or more.

 The ethyleneoxy (A), propyleneoxy (B) and butyleneoxy (0) group (s) may be randomly distributed, alternately distributed, or in the form of two, three, four or more blocks in any order. Can be distributed.

In a preferred embodiment of the invention, in the presence of a plurality of different alkyleneoxy blocks, the order of R ¹ , butyleneoxy block, propyleneoxy block, ethyleneoxy block is preferred. The butylene oxide used should comprise at least 80% 1,2-butylene oxide, preferably more than 90% 1,2-butylene oxide.

In the above general formula, X is an alkylene group or alkenylene group having 0 to 10, preferably 0 to 3 carbon atoms. The alkylene group is preferably a methylene, ethylene or propylene group.

In the cited prior art, there is often no specific information regarding the description of the C ₄ epoxide. This can generally be understood to mean 1,2-butylene oxide, 2,3-butylene oxide, isobutylene oxide and mixtures of these compounds. The composition generally depends on the C ₄ olefins used, and to a certain extent on the oxidation process.

In the above formula, Y is a sulfonate, sulfate or carboxyl group or phosphate group.

In the formula, M ⁺ is a cation, preferably ^{Na +, K +, Li +} , NH 4 +, H +, Mg 2 + and cations selected from the group of Ca ^2+.

The alcohol R ¹ -0H corresponding to the interface in a manner known in principle, the active agent of the general formula can be prepared by a misfire alkoxyl. The performance of such alkoxylation is known in principle to those skilled in the art. Likewise, it is known to those skilled in the art that the molar mass distribution of alkoxylates can be influenced through reaction conditions, in particular through catalyst selection.

Surfactants of the general formula can preferably be prepared by base accelerated alkoxylation. In this case, it is the alcohol R ¹ -0H preferably an alkali metal hydroxide, it can be mixed in the potassium hydroxide or alkali metal alkoxide, e.g. sodium methoxide and the pressure reactor. The water still present in the mixture can be discharged by reduced pressure (eg below 100 mbar) and / or by increasing the temperature (30 to 150 ° C.). The alcohol is then present in the corresponding alkoxide form. Thereafter, it is inactivated with an inert gas (eg nitrogen) and the alkylene oxide (s) are added stepwise at a temperature of 60 to 180 ° C. up to a maximum pressure of 10 bar. In a preferred embodiment, the alkylene oxide is initially metered at 130 ° C. In the course of the reaction, the temperature increases to 170 ° C. as a result of the heat of reaction released. In a further preferred embodiment of the invention, butylene oxide is first added at a temperature in the range 135 to 145 ° C., then propylene oxide is added at a temperature in the range 130 to 145 ° C., followed by ethylene oxide at 125 to Add at a temperature in the range of 145 ° C. At the end of the reaction, the catalyst can be neutralized, for example by adding an acid (eg acetic acid or phosphoric acid) and filtered if necessary.

However, alkoxylation of the alcohol R ¹ -OH can also be carried out by other methods, for example by acid promoted alkoxylation. In addition, double hydroxide clays can be used, as described, for example, in DE 43f5237 A1, or double metal cyanide catalysts (DMC catalysts). Suitable DMC catalysts are for example disclosed in DE 10243361 A1, in particular in the paragraphs [0029] to [0041] and in the literature cited therein. For example, a catalyst of the Zn-Co type can be used. To carry out the reaction, alcohol R ¹ -OH can be mixed with the catalyst and the mixture can be dehydrated as described above and reacted with alkylene oxide as described. Typically up to 1000 ppm of catalyst is used, based on the mixture, and the catalyst may remain in the product due to this small amount. The amount of catalyst may generally be less than 1000 ppm, for example 250 ppm or less.

The anionic group is finally introduced. This is known in principle to the skilled person. In the case of sulfate groups, the reaction with sulfuric acid, chlorosulfonic acid or sulfur trioxide can be carried out in a falling film reactor, for example by subsequent neutralization. In the case of sulfonate groups, for example, reaction and subsequent neutralization with propane sultone, reaction and subsequent neutralization with butane sultone, reaction with sodium sulfonic acid vinyl salt or sodium salt of 3-chloro-2-hydroxypropanesulfonic acid salt Can be carried out. In the case of carboxylate groups, for example, the oxidation of alcohols with oxygen and subsequent neutralization or reaction with sodium chloroacetic acid salts can be carried out.

Additional surfactants

In addition to the surfactants of the above general formula, the formulation may additionally optionally further comprise a surfactant. These are for example anionic surfactants of the alkylarylsulfonate or olefinsulfonate (alpha-olefinsulfonate or internal olefinsulfonate) type and / or nonionic surfactants of the alkyl ethoxylate or alkyl polyglucoside type. Such further surfactants may in particular also be oligomeric or polymeric surfactants. It is advantageous to use such polymeric cosurfactants to reduce the amount of surfactant needed to form microemulsions. Such polymeric cosurfactants are therefore also referred to as "microemulsion boosters". Examples of such polymeric surfactants include amphiphilic block copolymers comprising one or more hydrophilic blocks and one or more hydrophobic blocks. Examples include polypropylene oxide-polyethylene oxide block copolymers, polyisobutene-polyethylene oxide block copolymers and comb polymers having polyethylene oxide side chains and hydrophobic backbones, where the backbone is preferably substantially as monomer Olefin or (meth) acrylate. The term "polyethylene oxide" herein should include a polyethylene oxide block comprising propylene oxide units in each case as defined above. Further details of such surfactants are disclosed in WO 2006/131541 A1.

Mineral oil  Extraction method

In the mineral oil extraction method according to the invention, a suitable aqueous formulation of the surfactant of the general formula is injected into the mineral oil deposit via at least one injection borehole and the crude oil is discharged from the deposit via at least one preparation borehole. In this process, the term "crude oil" does not mean a single phase oil, but rather a general crude oil-water emulsion. In general, the deposit is provided by several injection boreholes and several manufacturing boreholes.

The main effect of the surfactant is in reducing the interfacial tension between water and oil, preferably significantly below 0.1 mN / m. After injection of a surfactant formulation known as "surfactant floating" or preferably Windsor III type "microemulsion floating", water is injected into the strata ("water floating") or preferably a strong thickening action ( The pressure can be maintained by injecting into the higher viscosity aqueous solution of the polymer having " polymer floating "). However, techniques are also known in which surfactants are allowed to act first in the strata. A further known technique is the injection of a solution of surfactant and thickening polymer followed by a solution of thickening polymer. Those skilled in the art know the details of the industrial performance of "surfactant floating," "water floating," and "polymer floating" and will use appropriate techniques depending on the type of deposit.

For the process according to the invention, an aqueous formulation comprising a surfactant of the above general formula is used. In addition to water, the preparation may optionally also comprise a water miscible or at least water dispersible organic material or other material. Such additives are particularly provided to stabilize the surfactant solution during storage or transportation to the oil field. However, the amount of such additional solvent should generally be 50% by weight or less, preferably 20% by weight. In a particularly advantageous embodiment of the invention, water is used exclusively in the formulation. Examples of water miscible solvents include in particular alcohols such as methanol, ethanol and propanol, butanol, sec-butanol, pentanol, butyl ethylene glycol, butyl diethylene glycol or butyl triethylene glycol.

According to the invention, the proportion of surfactants of the general formula is at least 30% by weight, based on the proportion of all surfactants present, ie the surfactants of the formula and optionally present. This ratio is preferably 50% by weight or more.

The mixtures used according to the invention can preferably be used for surfactant flotation of deposits. Particularly suitable for Windsor III type microemulsion floating (floating in the Windsor III range or in the range of the presence of a double continuous microemulsion). The technique of microemulsion flotation is already described in detail in the introduction.

In addition to the surfactant, the preparation may also comprise further components, such as C ₄ -C ₈ alcohols and / or basic salts (so-called “alkaline surfactant floating”). Such additives can be used, for example, to reduce stagnation in the strata. The ratio of alcohols is generally at least 1: 1, based on the total amount of surfactant used. However, it is also possible to use a significant excess of alcohol. The amount of basic salts may typically range from 0.1% to 5% by weight.

The optical image in which the method is used generally has a temperature of at least 10 ° C, for example 10 to 150 ° C, preferably at least 15 ° C to 120 ° C. The sum of the total concentrations of all surfactants is from 0.05 to 5% by weight, preferably from 0.1 to 2.5% by weight, based on the total amount of the aqueous surfactant formulation. A person skilled in the art can make a suitable choice depending on the desired properties, in particular according to the conditions in the mineral holding layer. It will be apparent to those skilled in the art that the agent can be mixed with stratified water, or since the surfactant can also be absorbed on the solid surface of the strata, the concentration of the surfactant can change after injection. It is a great advantage of the mixtures used according to the invention that the surfactants produce particularly good interfacial tension reduction.

It is of course possible and also preferred first to prepare a concentrate which is only diluted in situ at the desired concentration for injection into the strata. Generally, the total concentration of surfactant in this concentrate is 10 to 45% by weight.

The following examples are intended to illustrate the invention in detail:

part  I: Synthesis of Surfactants

General Method 1: Alkoxylation by KOH Catalysis

(Applies to the use of EO, PO and / or 1,2-BuO)

In a 2 L autoclave, the alcohol to be alkoxylated (1.0 equiv) was mixed with an aqueous KOH solution comprising 50 wt.% KOH. The amount of KOH was 0.2% by weight of the product to be prepared. With stirring, the mixture was dehydrated at 100 ° C. and 20 mbar for 2 hours. Then, it purged three times with N _2, and establish the supply pressure of the N ₂ of about 1.3 bar and the temperature was increased to 120 to 130 ℃. The temperature remains at 125 ° C to 135 ° C (for ethylene oxide), 130 to 140 ° C (for propylene oxide) or 135 to 145 ° C (for 1,2-butylene oxide) Alkylene oxide was weighed to remain. Thereafter, the mixture was stirred for additional 5 hours at 125 to 145 ° C, purged with N ₂ , cooled to 70 ° C and the reactor was emptied. The basic crude product was neutralized with acetic acid. Alternatively, neutralization can also be carried out with commercial magnesium silicate, which is subsequently filtered. The pale color product was characterized by ¹ H NMR spectra in CDCl ₃ , gel permeation chromatography, and OH crystals to determine the yield.

General method 2: alkoxylation by DMC catalysis for 2,3-butylene oxide

In a 2 L autoclave, the alcohol to be alkoxylated (1.0 equiv) was mixed with a double metal cyanide catalyst (eg, a DMC catalyst of the Zn-Co type from BASF) at 80 ° C. To activate the catalyst, approximately 20 mbar was applied at 80 ° C. for 1 hour. The amount of DMC was 0.1% by weight or less of the product to be prepared. Then, it purged three times with N _2, and establish the supply pressure of the N ₂ of about 1.3 bar and the temperature was increased to 120 to 130 ℃. The temperature remains at 125 ° C to 135 ° C (for ethylene oxide), 130 to 140 ° C (for propylene oxide) or 135 to 145 ° C (for 1,2-butylene oxide) Alkylene oxide was weighed to remain. Thereafter, the mixture was stirred for additional 5 hours at 125 to 145 ° C, purged with N ₂ , cooled to 70 ° C and the reactor was emptied. The pale color product was characterized by ¹ H NMR spectra in CDCl ₃ , gel permeation chromatography and OH crystals to determine the yield.

General Method 3: Sulfation with Chlorosulfonic Acid

In an 11-neck round bottom flask, the alkyl alkoxylate (1.0 equiv) to be sulfated was dissolved in a 1.5-fold amount (by weight percent) of dichloromethane and cooled to 5-10 ° C. Thereafter, chlorosulfonic acid (1.1 equiv) was added dropwise so that the temperature did not exceed 10 占 폚. The mixture was warmed to room temperature and stirred at this temperature for 4 hours under a stream of N ₂ , and then the reaction mixture was added to half the volume of aqueous NaOH solution at up to 15 ° C. The amount of NaOH was calculated to be slightly excess based on the chlorosulfonic acid used. The resulting pH was approximately pH 9-10. Dichloromethane was removed at 50 ° C. in a rotary evaporator under mild vacuum.

The product was characterized by ¹ H NMR and the water content of the solution (approximately 70%) was determined.

For the synthesis, the following alcohols were used.

Performance test

The following tests were performed using the surfactants obtained to assess their suitability for tertiary mineral oil extraction.

Determination of the test method

SP ^* Decision

(a) Measuring principle:

The interfacial tension between water and oil was determined in a known manner through the measurement of solubilization parameters (SP ^* ). Determination of the interfacial tension through the determination of the solubilization parameter SP ^* is a method for approximating the interfacial tension adopted in the art. The solubilization parameter (SP ^* ) indicates how much ml of oil is microemulsion (type Windsor III). If the same volumes of water and oil are used, the interfacial tension (σ) (IFT) can be calculated from this via the approximation IFT ≒ 0.3 / (SP ^* ) ² (C. Huh, J. Coil. Interf. Sc. , Vol. 71, No. 2 (1979)).

(b) procedure

To determine the SP ^* , a 100 ml measuring cylinder with a magnetic stirrer bar was filled with 20 ml oil and 20 ml water. To this was added a concentrate of the specific surfactant. Subsequently, the temperature was increased step by step from 20 to 90 ° C. and microemulsion foam was observed in this temperature window.

The formation of microemulsions can be assessed visually or by other conductivity measurements. A three phase system was formed (upper oil phase, intermediate microemulsion phase, lower water phase). When the upper and lower phases were the same size and did not change over a period of 12 hours, the optimum temperature T _opt of the microemulsion was observed. The volume of the intermediate phase was determined. The volume of surfactant added was subtracted from this volume. The value obtained was then divided by two. This volume is then divided by the volume of surfactant added. The results were recorded as SP ^* .

The type of oil and water used to determine the SP ^* was determined according to the system to be inspected. The mineral oil itself or a model oil such as decane can be used. The water used to better model the conditions in the mineral oil bed can be pure or saline. The composition of the aqueous phase can be adjusted according to the composition of the particular deposit, for example.

Information concerning awards and awards used can be found below in the individual descriptions of the tests.

Test result

A 1: 1 mixture of decane and NaCl solution was mixed with butyl diethylene glycol (BOG). Butyl diethylene glycol (BOG) acts as a cosolvent and is not included in the calculation of SP ^* . To this was added a surfactant mixture consisting of 3 parts alkyl alkoxy sulfate and 1 part dodecylbenzene sulfonate (Lutensit A-LBN 50; BASF). The total surfactant concentration was reported as weight percent of total volume.

In addition, a 1: 1 mixture from decane and sodium chloride solution was mixed with butyl diethylene glycol (BOG). Butyl diethylene glycol (BOG) acted as a co-solvent and did not consider SP ^* . The surfactant mixture was added with 3 parts alkyl alkoxy sulfate and 1 part secondary alkyl sulfonate (Hostapur SAS 60; Clariant). The total surfactant concentration in weight percent relates to the water phase.

In addition, a 1: 1 mixture of West German crude (API 33 °) and NaCl solution was mixed with butyl diethylene glycol (BOG). Butyl diethylene glycol (BOG) acted as a co-solvent and did not consider SP ^* . To this was added a surfactant mixture consisting of 3 parts alkyl alkoxy sulfate and 1 part dodecylbenzenesulfonate (Lutensit A-LBN 50; BASF). The total surfactant concentration was reported as weight percent of total volume.

In two further tests, a 1: 1 mixture from crude oil and sodium chloride solution from West Germany (API 33 °) or a 1: 1 mixture from crude oil Canada (API 14 °) and sodium chloride solution was added to butyl diethylene glycol ( BOG). Butyl diethylene glycol (BOG) acted as a co-solvent and did not consider SP ^* . A surfactant mixture consisting of 3 parts alkyl alkoxy sulfate and 1 part secondary alkyl sulfonate (Hostapur SAS 60; Clariant) was added respectively. Each total surfactant concentration in weight percent relates to the aqueous phase.

Results for surfactants based on linear and branched alcohols are listed in Tables 1-7.

TABLE 1 Linear C ₁₆ C ₁₈ -Alcohol-Based Surfactants

Carried out in Table 1. Examples C1 and, as is clear from C3 or C2 and C4, there is a C ₁₆ C ₁₈ -7 PO- sulfate and C ₁₆ C ₁₈ -9 PO- slight difference in SP ^* between sulfate. In this regard, it should be noted that comparisons should be made at similar T _opts to exclude temperature effects. This can have a significant impact in the case of surfactants with nonionic components.

When using BuO containing C ₁₆ C ₁₈ -alkoxy sulfates, surprising findings exist. Examples 5 and 6 show surprisingly stable SP ^* = 16 whether the introduction of two 1,2-butylene oxide units and seven propylene oxide units between C ₁₀ C ₁₈ -fatty alcohols is at 47 ° C. or 62 ° C. It is generated. A similar picture appears at reduced total surfactant concentration. In Example 11, SP ^* is 15 at 72 ° C. Purely, PO containing compounds having the same degree of alkoxylation show greater variation (C3 and C4), or SP ^* decreases to a slightly greater extent at reduced total surfactant concentrations (C9 and C10).

The arrangement of 1,2-butylene oxide between propylene oxide blocks and sulfate groups as in Comparative Examples C7 and C8, on the contrary, is less preferred. SP ^* is at a slightly lower level and changes more significantly with consideration of different temperatures.

The use of 2,3-butylene oxide is significantly poorer. As can be seen in C12, SP ^* is substantially half at SP ^* = 8 and is therefore poorer than alkyl propoxy sulfate (C9) with the same degree of alkoxylation. Surprisingly, not only the number of carbon atoms but also their spatial arrangement greatly affects the surfactant's ability to reduce interfacial tension. As in the case of 2,3-butylene oxide, undesirable batches actually have a cleaving effect and produce poorer values than for the corresponding surfactants without alkylene oxides having 4 carbon atoms. US 3890239 or US 4448697 does not describe this.

Interestingly, there is a sharp improvement as soon as the content of 1,2-butylene oxide units is at least three in the linear C ₁₆ C ₁₈ -fatty alcohols. In Example 13, the introduction of these three units raises SP ^* to 23.5. This can be further improved while increasing to even five units or less (Examples 14-16). SP ^* is even greater than 30 here.

Table 2 Surfactants Based on Branched Alcohols

A similar picture occurs in Table 2. Here, using alkyl alkoxy sulfates based on branched iC ₁₇ -alcohols demonstrates that there is an effect that does not contribute only to linear alcohol.

Comparative Examples C1 and 2 show very clearly that the use of 1,2-butylene oxide instead of propylene oxide is clearly advantageous in surfactants having the same degree of alkoxylation. At similar temperatures, SP ^* is three times higher. The placement of 1,2-BuO directly into the alkyl moiety (as in Examples 5 and 6) also results in lower interfacial tension than, for example, a different arrangement than in Example 4.

TABLE 3 Surfactants based on branched C ₁₆ Guerbet alcohols compared to C ₁₆ C ₁₈ -alcohol-based surfactants

As can be seen in Table 3, a similar picture applies here. If the surfactant based on linear alcohol contains more than two 1,2-BuO units, there is a clear spike of SP ^* and thus reduces the interfacial tension. Compared to Examples 3 and 4, Example 2 shows the difference between surfactants based on linear C ₁₆ C ₁₈ -alcohols and surfactants based on branched C ₁₆ gerbe alcohols. In Guerbe-based surfactants, SP ^* has already been obtained which is considerably better upon introduction of two 1,2-butylene oxide units than when surfactants are based on linear alcohols with similar chain lengths. However, the introduction of an additional amount of 1,2-butylene oxide in the case of linear alcohol could achieve approximately the same SP ^* level as in Example 4, as can be seen in Example 5.

In Example 6 it can be seen that the introduction of ten EO and PO blocks between the sulfate groups can substantially compensate for the additional degree of hydrophobicity of the 7-BuO block. It can therefore be compared with Comparative Example C1 under similar conditions (similar salt content, similar temperature T _opt ).

Without the introduction of 1,2-butylene oxide, as can be seen in Comparative Examples C7 and C8, the surfactant is only an average surfactant. Example 11 shows that only one equivalent of 1,2-BuO introduces a particular improvement in SP ^* . C ₁₆ only with the introduction of 2 equivalents 1,2-BuO In the case of Guerbe-based surfactants, a significant improvement occurred (Example 3).

[Table 4] Testing with West German Crude Oil

As can be seen in Table 4, substantially the same figure was also produced with crude oil as compared to the test with decane model oil. Comparative Example C1 resulted in significantly lower SP ^* values, and thus higher interfacial tension than the BuO containing surfactant in Example 2 at comparable temperatures. Comparative Example C3 and Example 4 show the advantage of 1,2-butylene oxide in a similar manner.

Table 5 Tests are decanes at similar temperatures and salinities

The aqueous surfactant solution mixed with BOG is clearly soluble under optimum conditions (salts and T _opt are produced by the addition of an oil three-phase system (type Windsor III)). As can be seen in Table 5, the optimum conditions (salin and T _opt ) were very close. As can be seen in Example 2, the correct fine tuning of the degree of alkoxylation resulted in a surfactant having a hydrophilic-hydrophobic-balance similar to that in Example V1. SP ^* in Example 2 was much higher. As a result, the interfacial tension was much lower.

TABLE 6 Test with crude oil from Germany (API 33 °) at similar temperature and salinity

The aqueous surfactant solution mixed with BOG is clearly soluble under optimum conditions (salts and T _opt are produced by the addition of an oil three-phase system (type Windsor III)). As can be seen from Table 6, the optimum conditions (salin and T _opt ) were very close. As can be seen in Example 2, the correct fine tuning of the degree of alkoxylation resulted in a surfactant having a hydrophilic-hydrophobic-balance similar to that in Example V1. SP ^* in Example 2 was much higher. As a result, the interfacial tension was much lower.

TABLE 7 Test with crude oil from Canada (API 14) at similar temperature and salinity

The aqueous surfactant solution mixed with BOG is clearly soluble under optimum conditions (salts and T _opt are produced by the addition of an oil three-phase system (type Windsor III)). As can be seen from Table 7, the optimum conditions (salin and T _opt ) were very close. As can be seen in Example 2, the correct fine tuning of the degree of alkoxylation resulted in a surfactant having a hydrophilic-hydrophobic-balance similar to that in Example V1. SP ^* in Example 2 was also much higher. As a result, the interfacial tension was much lower.

Claims (16)

In order to reduce the interfacial tension between oil and water to less than 0.1 mN / m, an aqueous surfactant formulation comprising at least one ionic surfactant is injected into the mineral oil deposit via one or more injection boreholes and one crude oil A method of extracting mineral oil by Winsor III microemulsion flotation, which is discharged from a deposit through a borehole, wherein the surfactant formulation comprises at least one surfactant of the general formula:

[Wherein,
R ¹ is a linear or branched, saturated or unsaturated, aliphatic and / or aromatic hydrocarbon radical having 8 to 30 carbon atoms,
A is ethyleneoxy,
B is propyleneoxy,
D is butyleneoxy,
l is 0 to 99,
m is 0 to 99,
n is from 1 to 99,
X is an alkyl or alkylene group having 0 to 10 carbon atoms,
M ⁺ is a cation,
Y ⁻ is selected from the group of sulfate groups, sulfonate groups, carboxylate groups and phosphate groups,
The A, B and D groups can be distributed randomly, alternately or in any order in the form of 2, 3, 4 or more blocks, the sum of l + m + n ranges from 3 to 99, 1, The proportion of 2-butylene oxide is at least 80% based on the total amount of butylene oxide]. The method of claim 1, wherein the sum of l + m + n is in the range of 5-50. The method according to claim 1 or 2, wherein the proportion of 1,2-butylene oxide is at least 90% based on the total amount of butylene oxide. 4. The method of claim 1, wherein the surfactant of the general formula comprises 2 to 15 1,2-butylene oxide units. 5. The method of claim 1, wherein the sum of the concentrations of all surfactants is from 0.05 to 5% by weight, based on the total amount of the aqueous surfactant formulation. 6. The method according to any one of claims 1 to 5,
m is 5 to 9,
n is 2 to 10,
Y ⁻ is selected from the group of sulfate groups, sulfonate groups and carboxylate groups,
The groups A, B and D are present in an order of greater than 80% in the form of blocks D, B, A starting from R ¹ , the sum of l + m + n ranges from 7 to 49 and 1,2-butylene And the proportion of oxide is at least 90% based on the total amount of butylene oxide in the molecule. The method of claim 6, wherein R ¹ is a linear fatty alcohol having 16 or 18 carbon atoms and n is 3 to 10. 8. Surfactant formulations comprising at least one ionic surfactant of the general formula:

[Wherein,
R ¹ is a linear or branched, saturated or unsaturated, aliphatic and / or aromatic hydrocarbon radical having 8 to 30 carbon atoms,
A is ethyleneoxy,
B is propyleneoxy,
D is butyleneoxy,
l is 0 to 99,
m is 0 to 99,
n is from 1 to 99,
X is an alkyl or alkylene group having 0 to 10 carbon atoms,
M ⁺ is a cation,
Y ⁻ is selected from the group of sulfate groups, sulfonate groups, carboxylate groups and phosphate groups,
The A, B and D groups can be distributed randomly, alternately or in any order in the form of 2, 3, 4 or more blocks, the sum of l + m + n ranges from 3 to 99, 1, The proportion of 2-butylene oxide is at least 80% based on the total amount of butylene oxide]. 9. The method of claim 8,
m is 5 to 9,
n is 2 to 10,
Y ⁻ is selected from the group of sulfate groups, sulfonate groups and carboxylate groups,
The groups A, B and D are present in an order of greater than 80% in the form of blocks D, B, A starting from R ¹ , the sum of l + m + n ranges from 7 to 49 and 1,2-butylene The proportion of oxide is at least 90% based on the total amount of butylene oxide in the molecule. 10. The surfactant formulation of claim 9, wherein R ¹ is a linear fatty alcohol having 16 or 18 carbon atoms and n is 3 to 10. The surfactant formulation according to any one of claims 8 to 10, wherein the sum of the concentrations of all surfactants is from 0.05 to 5% by weight, based on the total amount of the aqueous surfactant formulation. Surfactants of the general formula:

[Wherein,
R ¹ is a linear or branched, saturated or unsaturated, aliphatic and / or aromatic hydrocarbon radical having 8 to 30 carbon atoms,
A is ethyleneoxy,
B is propyleneoxy,
D is butyleneoxy,
l is 0 to 99,
m is 0 to 99,
n is from 1 to 99,
X is an alkyl or alkylene group having 0 to 10 carbon atoms,
M ⁺ is a cation,
Y ⁻ is selected from the group of sulfate groups, sulfonate groups, carboxylate groups and phosphate groups,
The A, B and D groups can be distributed randomly, alternately or in any order in the form of 2, 3, 4 or more blocks, the sum of l + m + n ranges from 3 to 99, 1, The proportion of 2-butylene oxide is at least 80% based on the total amount of butylene oxide]. 13. The surfactant of claim 12, wherein the sum of l + m + n ranges from 3 to 49. The surfactant according to claim 12 or 13, wherein the proportion of 1,2-butylene oxide is 90% or more based on the total amount of butylene oxide. The surfactant according to claim 12, wherein R ¹ is a linear or branched, saturated or unsaturated, aliphatic and / or aromatic hydrocarbon radical having 10 to 30 carbon atoms. 16. The method according to any one of claims 12 to 15,
R ¹ is a linear fatty alcohol having 16 or 18 carbon atoms,
m is 5 to 9,
n is 3 to 10,
Y ⁻ is selected from the group of sulfate groups, sulfonate groups and carboxylate groups,
The groups A, B and D are present in an order of greater than 80% in the form of blocks D, B, A starting from R ¹ , the sum of l + m + n ranges from 7 to 49 and 1,2-butylene The proportion of oxide is at least 90% based on the total amount of butylene oxide in the molecule.