DE102009002555A1 - Use of complexing agents for the prevention of asphaltene and/or naphthenate-precipitation from crude oil, comprising oil-soluble, divalent complexing agent - Google Patents

Abstract

Use of complexing agents (A) for the prevention of asphaltene and/or naphthenate-precipitation from crude oil, comprising at least one oil-soluble, at least divalent complexing agent, provided that the solubility of the complexing agent in 2-propylheptanol at room temperature is at least 50 g/kg, is claimed.

Description

The Invention relates to the use of oil-soluble, at least bidentate complexing agents, preferably from Phosphonic acid groups containing complexing agents to avoid of asphaltene and / or naphthenate precipitates from crude oil.

crude oils are mixtures of many different components, the composition of crude oil varies according to origin. In addition to different Hydrocarbons also contain crude oils called asphaltenes. These are polycyclic aromatic hydrocarbons different structure, which in addition heteroatoms like N, O and S include and on their surface with resins are stabilized. Asphaltenes can be made from crude oil but failures are a surplus of heptane soluble in benzene. The asphaltene content of crude oils can vary greatly depending on the origin of the crude oil. While light crude oils only low asphaltene content of approx. 1% or less, heavy oils can be more contain as 20 wt .-% asphaltenes.

Farther Petroleum oils also contain so-called naphthenic acids. These are carboxylic acids of saturated (poly) cyclic hydrocarbons. Naphthenic acids fall when adding heptane to crude oil is not enough.

Either Asphaltenes as well as naphthenic acids can during crude oil production, crude oil processing and the crude oil transport to unwanted precipitations to lead. Such precipitates can already occur underground in the petroleum formation and Clogging pores in the formation, resulting in the production productivity is at least reduced or come to an extreme stop altogether can. Precipitations may also occur above ground the workup and transport occur, for. B. in the devices for the splitting of crude oil-water emulsions or in pipelines. They also reduce productivity here, because either processes, such as the separation of crude oil and water, can be slowed down or even completely come to a standstill. Furthermore, must from precipitates affected or clogged plants are shut down for cleaning.

asphalts and / or naphthenate precipitates are particularly by favored the presence of metal ions. While Naphthenate precipitates mainly caused by calcium ions can be asphaltene precipitation especially caused by iron ions.

Metal ions can naturally occur in the reservoir water, but they can also be released or formed in the course of so-called acid treatment (acidizing, fracturing) in the oil reservoir. Also through so-called squeeze treatments, metal ions can enter the deposit. In an acid treatment, an acid, such as hydrochloric acid, is injected into the petroleum deposit to increase its permeability by dissolving contaminants and / or forming new pores, thus ensuring unimpeded oil recovery. For carbonaceous deposits, large amounts of calcium ions can form in this case. Iron ions may form through contact of the acid with iron parts, such as downhole installations or by dissolving iron contaminants in the formation. The iron components in the aqueous phase after the treatment may u. U. be very high; Values of up to 10% by weight have already been reported (for example from Barker et al., "Inhibition and Removal of Low-pH Fluid-Induced Asphaltic Sludge Fouling Fouling Formations in Oil and Gas Wells," SPE International Symposium to Oilfield Chemistry, Houston, Texas, USA, 28.2. - 02.03.2007, publication SPE 102738 ).

to Prevention of asphaltene or naphthenate precipitates In the prior art, a number of tools have already been proposed Service.

It calcium naphthenate precipitates in acids, For example, acetic acid to dissolve. The usage However, acids in separators or pipelines can cause corrosion result in addition to corrosion inhibitors must be used.

US 6,313,367 discloses the use of esters of carboxylic acids and polyols having 2 to 100 carbon atoms, ethers of Fettepoxiden or Fettgylcidylethern and polyols and esters of Fettepoxiden or Fettgylcidylethern and carboxylic acids to prevent Asphaltenausfällungen.

US 6,063,146 . US 7,122,112 and US 2007/0124990 disclose the use of polyether carboxylic acids, compounds having amide and carboxyl groups and imidazoline compounds as dispersing aids for asphaltenes in crude oil.

It is also known to add formulations for the acid treatment of petroleum formations water-soluble complexing agents to prevent the formation of precipitates. EP 191 524 A2 and WO 01/83639 propose the use of EDTA or hydroxyethylaminocarboxylic acids, and US 5,293,942 suggests the use of 2-ketogluconates.

EP 717 167 A2 discloses the use of glycine-N, N-diacetic acid derivatives as complexing agents for alkaline earth and heavy metal ions in the production and transportation of petroleum and natural gas.

WO 03/062344 A2 discloses the treatment of subterranean formations with an aqueous formulation comprising an acid, iron ions, a scale inhibitor and a reducing agent. As a scale inhibitor, various water-soluble phosphonates can be used in addition to other compounds, such as hydroxyethyliminobismethylenephosphonic acid, fatty amine phosphonates, triethanolamine phosphate esters and completely phosphonomethylated diethylenetriamine and triethylenetetramine.

WO 98/14621 discloses hydrocarbyl-soluble aminomethylenephosphonic acid derivatives for the extraction of metal ions from aqueous solutions. The use of the phosphonic acid derivatives to prevent asphaltene and / or naphthenate precipitates is not disclosed.

task The invention was to provide improved inhibitors or Elimination of asphaltene and / or naphthenate precipitates to provide.

Accordingly was the use of oil-soluble complexing agents to avoid asphaltene and / or naphthenate precipitates found from crude oil, which is the complexing agent by at least one oil-soluble, at least bidentate Complexing agent, with the proviso that the solubility the complexing agent in 2-propylheptanol at room temperature at least 50 g / kg.

In a preferred embodiment of the invention, the complexing agents are amines which comprise as substituents methylenephosphonic acid groups -CR ₂ -PO ₃ H ₂ and hydrocarbon groups having 6 to 30 C atoms.

through the use according to the invention oil-soluble Chelating agent will be the appearance of asphaltene and / or naphthenate precipitates effectively inhibited.

More specifically, the following is to be accomplished for the invention:
According to the invention, oil-soluble, at least bidentate, complexing agents are used as aids to avoid asphaltene and / or naphthenate precipitates. The term "avoidance of asphaltene and / or naphthenate precipitates" should be understood that by using the complexing agent according to the invention asphaltene and / or naphthenate precipitates of crude oil not even occur or at least the amount is reduced, each in comparison to a situation in which the complexing agent is not used. The term is intended to imply that by the use of the complexing agent already formed asphaltene and / or naphthenate precipitates can be completely or at least partially dissolved again.

Used complexing agents

At least bidentate complexing agents are also considered chelating Complexing agent known. Under "chelating group" becomes in a known manner an at least bidentate Understood group, which can bind metal ions and which at the formation of complexes with metal ions at least two coordination sites can occupy at the central metal ion. The complexing agents used further comprise at least one hydrophobic group.

The hydrophobic groups impart the inventively used Complexing agent has good solubility in organic phases, especially in oil phases. The complexing agents should be preferred Unlimited mixing with non-polar organic solvents be.

At least but is the solubility of the invention used Complexing agent in 2-propylheptanol at room temperature at least 50 g / kg, preferably at least 100 g / kg, more preferably at least 200 g / kg and most preferably at least 300 g / kg.

The chelating groups may preferably be O-atom coordinating groups act. Examples of such groups include COOH groups as well as in particular phosphoric acid and / or phosphonic acid groups. They are preferably complexing agents comprising phosphonic acid groups. The hydrophobic groups are preferably straight-chain, branched, saturated or unsaturated aliphatic and / or aromatic hydrocarbon radicals having 6 to 30 carbon atoms, preferably 6 to 22 carbon atoms. Preference is given to unbranched or branched alkyl radicals having 6 to 30 carbon atoms. The chelating groups and the hydrophobic groups can be linked together directly or via suitable linking groups. In a preferred embodiment of the invention, the complexing agents are amines which have as substituents both methylenephosphonic acid groups -CR ₂ -PO ₃ H ₂ and hydrocarbon groups with 6 to 30 carbon atoms. The phosphonic acid groups are capable of binding metal ions, and the hydrocarbon groups provide the complexing agents with good solubility in organic phases.

at the complexing agents used in the invention may be derivatives of monoamines (I), diamines (II) or polyamines (III). Complexing agent based on monoamines have the general formula (I).

Here, R ¹ is a straight-chain, branched, saturated or unsaturated aliphatic and / or aromatic hydrocarbon radical having 6 to 30 carbon atoms, preferably 6 to 22 carbon atoms, which may optionally be substituted by an OH group. Examples of such radicals include C ₆ - to C ₃₀ -alkyl, C ₆ - to C ₃₀ -alkenyl, C ₆ - to C ₃₀ -aryl or C ₇ - to C ₁₈ -alkylaryl radicals.

Suitable straight-chain or branched C ₆ - to C ₃₀ -alkenyl radicals are, for example, oleyl, linolyl and linolenyl radicals.

Examples of C ₆ - to C ₃₀ -aryl radicals include phenyl or naphthyl radicals and corresponding alkyl-substituted radicals such as tolyl or xylyl radicals.

As C _7-18 -Phenylalkylreste such as benzyl, 1-phenylethyl, 2-phenylethyl, 1-phenylpropyl, 2-phenylpropyl, 3-phenylpropyl, 2-phenylprop-2 to C - to C ₁₅ -alkylaryl, for example, but are particularly suitable C ₇ -yl, 4-phenylbutyl, 2,2-dimethyl-2-phenylethyl, 5-phenylamyl, 10-phenyldecyl, 12-phenyldodecyl. Particularly preferred are benzyl radicals.

It is preferably a straight-chain or branched C ₆ - to C ₃₀ -alkyl radical, more preferably a C ₆ - to C ₂₂ -alkyl radical and particularly preferably a C ₈ - to C ₂₀ -alkyl radical. Examples of such alkyl radicals include n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, iso-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, iso-tridecyl, n- Tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl and n-eicosyl. Most preferably, R ¹ is a 2-ethylhexyl radical.

Furthermore, it may be, R ¹ is a group -CH ₂ -CH (OH) -R act ^4, wherein R ⁴ is a a straight-chain, branched, saturated or unsaturated aliphatic and / or aromatic hydrocarbon radical having from 4 to 28 Carbon atoms, preferably 6 to 20 carbon atoms. R ⁴ is preferably phenyl or a straight-chain or branched C ₆ - to C ₂₀ -alkyl radical. For example, moieties of formula -CH ₂ CH (OH) -R ^{4 are} derived from long chain epoxidized α-olefins such as 1,2-epoxyhexane, 1,2-epoxyoctane, 1,2-epoxydecane, 1,2-epoxydodecane, 1, 2-epoxytetradecane, 1,2-epoxyhexadecane or 1,2-epoxyoctadecane or from styrene oxide.

The radical R ² is a methylenephosphonic acid group -CR ' ₂ -PO ₃ H ₂ or a salt thereof, it being possible for the radicals R' independently of one another to be hydrogen or a C ₁ - to C ₄ -alkyl radical. Preferably, at least one of R 'is hydrogen and more preferably both are hydrogen, ie R ² is -CH ₂ -PO ₃ H ₂ or a salt thereof.

The radical R ³ is a radical selected from the group of hydrogen, a C ₁ - to C ₅ -alkyl radical, R ¹ or R ² .

The complexing agents according to formula (I) are preferably those of the formula (R ¹ -) ₂ N-CH ₂ -PO ₃ H ₂ or R ¹ -N (-CH ₂ -PO ₃ H _{2) 2,} more preferably (R ¹ -) ₂ N-CH ₂ -PO ₃ H ₂ where R ^{1 is} preferably a 2-ethylhexyl radical. Of course, it may also be the corresponding salts, in particular the corresponding alkali metal salts.

complexing based on diamines have the general formula (II).

Here, R ⁴ is a straight-chain or branched C ₁ - to C ₁₂ -alkylene group, preferably a C ₂ - to C ₈ -alkylene group and particularly preferably a C ₂ - to C ₆ -alkylene group. Examples of R ⁴ radicals include methylene, 1,2-ethylene, 1,2-propylene, 1,3-propylene, dimethylmethylene, ethylmethylene, 1,2-butylene, 1,3-butylene, 2,3-butylene, 1, 4-butylene, 1,5-pentamethylene, 1,6-hexamethylene and 1,8-octamethylene. It is preferably 1,2-ethylene, 1,2-propylene or 1,3-propylene and particularly preferably 1,2-ethylene.

R ⁵ is independently a radical selected from the group of hydrogen, a C ₁ - to C ₅ -alkyl radical, R ¹ or R ² , with the proviso that at least one of the radicals R ⁵ is a R ¹ is radical and at least one further radical R ⁵ is a radical R ² .

Examples complexing agents (II) include those of the formulas (IIa), (IIb) and (IIc).

complexing based on polyamines have the general formula (II I).

Here R ^{4 has} the meaning defined above, wherein the different radicals R ⁴ in formula (III) may be the same or different. The radicals R ⁶ are each independently a radical selected from the group of hydrogen, a C ₁ - to C ₅ -alkyl radical, R ¹ or R ² .

Ein Rest der Formel (IV) stellt eine Verzweigung dar, welche selbst wiederum verzweigt sein kann.R ⁷ is a radical selected from the group of hydrogen, a C ₁ - to C ₅ -alkyl radical, R ¹ or R ² or a radical of the general formula (IV)

A radical of the formula (IV) represents a branch, which in turn may itself be branched.

The Indices n around m each have at least the value of 1, where the Sum of n and m adds over all branches-2 to 30000. Oligomers with a total n + m <10 can in this case linear or be shown, while polymers in of all rule branches.

The complexing agents of the formula (III) are at least 50%, preferably at least 60% and particularly preferably at least 75% of all the radicals R ⁶ and R ⁷ occurring in the molecule to radicals R ¹ and / or R ² , with the proviso the number ratio of hydrocarbon groups R ¹ to the methylenephosphonic acid groups R ² X _R ¹ / X _R ^{2 is} 10: 1 to 1: 2. The ratio X _R ¹ / X _R ^{2 is} preferably 5: 1 to 1: 1 and more preferably 2: 1 to 1: 1.

The number of substituents R ¹ and R ² in formula (IIII) and their ratio is in this case set by the skilled person depending on the desired properties of the complexing agent. He will pay attention here to a balance of the radicals R ¹ and R ² that a sufficient number of complexing groups in the molecule are present and on the other hand, a sufficient number of hydrocarbon groups to ensure sufficient solubility of the complexing agent in organic phases. When using relatively short-chain radicals R ¹ , that is, for example, radicals having about 6 to about 10 carbon atoms, a ratio X _R ¹ / X _R ² of not less than 1 is generally recommended in order to ensure sufficient solubility of the complexing agents in organic phases, especially to ensure oil phases; when using longer-chain radicals, for example from C ₁₆ - to C ₂₂ radicals, a smaller ratio can generally also be selected.

The complexing agents to be used according to the invention can be prepared by customary methods. Compounds with R ¹ = R ² = hydrogen can most easily be prepared by reacting corresponding amines with formaldehyde (or paraformaldehyde) and phosphorous acid with acid catalysis (eg inorganic acids or mineral acids such as sulfuric acid or hydrochloric acid, sulfonic acids such as p-toluenesulfonic acid or methanesulfonic acid or Carboxylic acids such as the mixture of glacial acetic acid / acetic anhydride).

such Reactions of amines with formaldehyde and phosphorous acid are usually at 0 to 150 ° C, in particular 50 to 120 ° C, especially 80 to 110 ° C performed. Amine, formaldehyde and phosphorous acid are advantageously, based on an N-H bond, in a molar ratio of 1: (2 to 6) :( 1 to 4) used.

alternative These compounds can also be obtained by hydrolysis Phosphonic acid ester, accessible by reaction with phosphites instead of phos phoric acid become.

One another synthetic route, in particular for connection with R '≠ H is of interest, starting from aldehydes (eg the Formula R'-CHO) or ketones (eg of the formula R'-CO-R ') and the corresponding primary amines, which converted into imines to which phosphorous acid is then added.

Oligomeric and polymeric complexing agents of the formula (III) can be obtained in a two-stage reaction by first treating a corresponding oligo- or polyamine, ie a compound (III) in which all radicals R ⁶ and R ^{7 are} hydrogen, in a first Step treated with an alkylating agent to obtain an oligo- or polyamine modified with groups R ¹ . This can be phosphonomethylated in a second stage as already described. Suitable oligo- or polyamines are, in particular, oligo- or polyethylenimines, preferably those having an average molar mass M _n of 2,000 to 60,000 g / mol, preferably 4,000 to 40,000 g / mol. It is clear to the person skilled in the art that the groups R ¹ and R ^{2 are in} this case bound statistically by the oligo- and polyamines, ie a mixture of different molecules is not formed, not a specific molecule. The above information on the number and the ratio of the groups R ¹ and R ² each refer to such a mixture.

Use of oil-soluble complexing

The described, oil-soluble complexing agents according to the invention for avoiding or Besei use of asphaltene and / or naphthenate precipitates from crude oil. It can be used for this purpose only one complexing agent or a mixture of several different complexing agents.

at Crude oil can be crude oil of any origin act. It may preferably be asphaltene-rich and / or naphthenic acid-rich Crude oils act. It may be, in particular, crude oils with an asphaltene content of more than 0.1% by weight, preferably more as 1% by weight and more preferably more than 5% by weight and completely most preferably more than 10 wt .-% act. It can continue in particular, crude oils with a naphthenic acid content of more than 0.01% by weight, preferably more than 0.1% by weight, and especially preferably more than 1 wt .-% act.

The In principle, use can be used in all phases of petroleum production, Work-up and transport done. The complexing agents can Underground according to the invention, d. H. in the formation or used in the borehole, or above ground in crude oil tanks, Pipelines and refining equipment, such as separators for separating crude oil-water emulsions.

to The oil-soluble complexing agents are used preferably added directly to the crude oil phase. This is by nature above-ground use easily possible. The oil-soluble Complex inhibitors can do this the crude oil phase can be added in substance or can be preferred as Solution in a suitable organic solvent or mixtures thereof are used. Examples of organic solvents include alcohols such as ethanol, propanol, isopropanol, butanol or i-decanol, ethers such as tetrahydrofuran or dioxane, paraffinic Solvents such as hexane, cyclohexane, heptane, octane, isooctane, Decane, light benzine fractions or aromatic solvents such as toluene, xylene or solvent naphtha.

The But complexing agents can also be in water or aqueous Solvent mixtures are dispersed and as a dispersion be used. Aqueous solvent mixtures include water and at least one water-miscible solvent, such as methanol, ethanol, n-propanol or i-propanol. aqueous In addition, formulations can also Surfactants or polymers as an aid for dispersing the oil-soluble Complexing agents include.

at The promotion of crude oil is usually a Promoted crude oil-water emulsion. The use of Complexing agent as an aqueous formulation naturally occurs everything considered, as long as the crude oil phase is not yet from the aqueous phase is separated.

Also when used as an aqueous formulation, the complexing agent gradually absorbed by the crude oil phase.

The Concentration of or used in the invention Complexing agent, based on the crude oil is According to the invention generally 1 ppm to 200,000 ppm, preferably 1 ppm to 5000 ppm, more preferably 2 ppm up to 2000 ppm and especially 5 ppm to 1000 ppm; the term "ppm" refers here in each case on the mass of crude oil.

At the underground use in the borehole or in the formation is direct Addition of the oil-soluble complexing agent to the crude oil phase not possible by nature. The oil-soluble Complexing agents must do this in the form of a suitable formulation be applied.

The Concentration of the complexing agents depends on the Application and will be selected by the expert. For an acid treatment (acidizing) has proven itself a concentration of complexing agent in the formulation of 0.01 Wt .-% to 2.5 wt .-%, without the invention to this range should be limited. For a typical "squeeze treatment" (i. H. the pressing of chemicals in high concentration in one Deposit, with the aim of there a "depot" of Create chemicals, which then gradually be removed and in the direction of the Produktuionsbohrung can also act significantly higher Concentrations, e.g. As formulations with up to about 50 wt .-% complexing agent used become.

she can do this, for example, in an aqueous Formulation for stimulation, if appropriate using appropriate Surfactants or polymers are used as dispersing aids.

In a preferred embodiment of the invention, however, the complexing agents used in the invention are introduced into the formation before the formation is treated with the acid. In this procedure, the complexing agent is already present in the formation before the acid attaches to the formation engages and strong metal ions are formed. For this purpose, the complexing agent is pressed into the formation in a suitable formulation, preferably as an organic solution. Particularly suitable solvents for this application are toluene, xylene or solvent naphtha. Only after pressing in the formulation of the complexing agent is the acidic formulation then injected into the formation. The pressing in takes place in each case through the production bore.

Farther may be used in the invention Complexing agent of course also in mixture with other aids to avoid asphaltene and / or naphthenate precipitates be combined.

The The following examples are intended to explain the invention in more detail.

Preparation of the invention used complexing

Complexing agent A:

Reaction product of di-2-ethylhexylamine with phosphorous acid and formaldehyde

(Synthesis accordingly WO 98/14621 , Example 1)

There were initially charged 289.8 g (1.20 mol) of di-2-ethylhexylamine and added dropwise 118.1 g (1.44 mol) of phosphorous acid dissolved in 160 ml of water. Subsequently, 85.2 g of concentrated sulfuric acid, which had been diluted with 75 ml of water, added. The resulting mixture was heated to about 100 ° C and 247 g (3.0 mol) of aqueous formaldehyde solution (36.5%) were added dropwise. It was refluxed for 40 hours. The organic phase was separated and washed 3 times with 500 ml of water. Residual water in the washed organic phase was removed in a water-jet vacuum. Yield: 370 g of yellow viscous oil (92% of theory); By-product: methyl-di- (2-ethylhexylamine); Elemental _analysis : P _gef. 7.1%, N _gef. 4.3%.

Complexing agent B: ethylene diamine tetraethylene phosphonic acid, sodium salt

Complexing agent C: 1-hydroxyethane (1,1 diphosphonic acid), sodium salt solubility tests:

It each solubility of the complexing agents A, B and C determined in 2-propylheptanol.

complexing A is more than 50% by weight soluble in 2-propylheptanol, while the complexing agents B and C in 2-propylheptanol are practically insoluble.

Summary

use of oil-soluble, at least bidentate Complexing agents, preferably having phosphonic acid groups Complexing agents, to avoid asphaltene and / or naphthenate precipitates from crude oil.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• US 6313367 [0009]
• - US 6063146 [0010]
• US 7122112 [0010]
• US 2007/0124990 [0010]
• - EP 191524 A2 [0011]
• WO 01/83639 [0011]
• - US 5293942 [0011]
• - EP 717167 A2 [0012]
• WO 03/062344 A2 [0013]
• WO 98/14621 [0014, 0062]

Cited non-patent literature

• Barker et al., "Inhibition and Removal of Low-pH Fluid-Induced Asphaltic Sludge Fouling Fouling Formations in Oil and Gas Wells," SPE International Symposium to Oilfield Chemistry, Houston, Texas, USA, 28.2. - 02.03.2007, publication SPE 102738 [0006]

Claims (13)

Use of complexing agents to prevent asphaltene and / or naphthenate precipitations from crude oil, characterized in that the complexing agent is at least one oil-soluble, at least bidentate complexing agent, with the proviso that the solubility of the complexing agent in 2-propylheptanol at Room temperature is at least 50 g / kg. Use according to claim 1, characterized characterized in that the crude oil has an asphaltene content of at least 1 wt .-%. Use according to claim 1, characterized characterized in that the crude oil has a naphthenic acid content of has at least 0.1 wt .-%. Use according to one of the claims 1 to 3, characterized in that it is a phosphonic acid groups comprehensive complexing agent acts. Use according to any one of claims 1 to 4, characterized in that the complexing agent is at least one selected from the group of complexing agents (I), (III) or (III), the complexing agents being defined as follows: (I) Derivatives of monoamines of the general formula (I)

wherein the radicals R ¹ , R ² and R ^{3 have} the following meaning: R ¹ : straight-chain, branched, saturated or unsaturated aliphatic and / or aromatic hydrocarbon radical having 6 to 30 carbon atoms, which may be optionally substituted by an OH group, R ² : -CR ' ₂ -PO ₃ H ₂ or a salt thereof, wherein the radicals R' independently of one another are hydrogen or a C ₁ - to C -alkyl radical, R ³ : a radical selected from the group of hydrogen , a C ₁ - to C ₅ -alkyl radical, R ¹ or R ² . (II) Derivatives of diamines of the general formula (II)

wherein the radicals R ⁴ and R ^{5 have} the following meanings: R ⁴ : straight-chain or branched C ₁ - to C ₁₂ -alkylene group, R ⁵ : independently of one another a radical selected from the group of hydrogen, C ₁ - to C ₅ -alkyl radicals R ¹ or R ² , with the proviso that at least one of the radicals R ⁵ is a radical R ¹ and at least one further radical R ⁵ is a radical R ² . (III) Derivatives of Oligo- or Polymines of the General Formula (III)

wherein the radical R ^{4 is} as defined above, and R ⁶ , R ⁷ and n have the following meaning: R ⁶ : independently of one another a radical selected from the group of hydrogen, C ₁ - to C ₅ -alkyl radicals, R ¹ or R ² , R ⁷ : a radical selected from the group of hydrogen, C ₁ - to C ₅ -alkyl radicals, R ¹ , R ² or a radical of the general formula (IV)

wherein the indices n each have at least the value of 1 and the sum of n and m added over all branches is 2 to 30,000, with the proviso that at least 50% of all residues R occurring in the complexing agent (III) are present ⁶ and R ⁷ are radicals R ¹ and / or R ² , wherein the numerical ratio of hydrocarbon groups R ¹ to the methylenephosphonic R ² X _R ¹ / X _R ^{2 is} 10: 1 to 1: 2. Use according to claim 5, characterized in that R ¹ is a straight-chain or branched C ₆ - to C ₃₀ -alkyl radical. Use according to claim 5 or 6, characterized in that R ² is -OH ₂ -PO ₃ H ₂ . Use according to claim 5, characterized in that it is at least one complexing agent (I) of the general formula (R ¹ -) ₂ N-CH ₂ -PO ₃ H ₂ or a salt thereof. Use according to claim 8, characterized in that R ¹ is a 2-ethylhexyl radical. Use according to one of the claims 1 to 9, characterized in that the complexing agent of Crude oil added. Use according to one of the claims 1 to 9, characterized in that one dissolved the complexing agent or dispersed in a suitable formulation in the petroleum formation einpresst. Use according to claim 11, characterized in that it is an acidic in the formulation Formulation for acid treatment of the formation is. Use according to claim 12, characterized in that in a two-step approach first a formulation of the complexing agent and in one second step to an acid-containing formulation Acid treatment into the formation presses. use of oil-soluble, at least bidentate Complexing agents to avoid asphaltene and / or naphthenate precipitates from crude oil.