MX2012009677A - Macromolecular amphiphilic compounds as water retention agents for construction chemical systems, especially for cementing of boreholes. - Google Patents

Abstract

The inventive water retention agents are outstandingly suitable as additives in construction chemical systems, and in the development, exploitation and completion of underground mineral oil and natural gas deposits, and in deep wells, the action thereof being particularly advantageous at elevated temperatures and due to their lack of influence on the rheological properties of the borehole muds.

Description

COMPOUNDS ANFIFÍLICOS, MACROMOLECULARES AS AGENTS OF WATER RETENTION FOR CHEMICAL SYSTEMS OF CONSTRUCTION, IN PARTICULAR FOR CEMENTATION OF WELLS The present invention relates to a water retention agent for chemical building systems, a process for the preparation of a amphiphilic, macromolecular compound suitable as a water retention agent, the use of this compound as a water retention agent in chemical construction systems and in the development, exploitation and completion of underground deposits of oil and natural gas and in deep wells, a mixture of construction material containing this compound, a formulation of construction material containing water and the mixture of construction material, and a structure produced with the use of this formulation of construction material.

In the chemical construction sector, various copolymers are often used as water retention agents, which are also referred to as fluid loss additives. A specific field of use in this context is the cementing of wells in the development, exploitation and completion of underground deposits of oil and natural gas and in deep wells.

Water retention agents or fluid loss additives have the function of reducing the release of water from a cement suspension. This is of particular importance in the area of oil and natural gas exploration since cement suspensions that substantially comprise cement and water are pumped through the annular space between the so-called tubing and the well wall in the cementing of the walls. wells During this procedure, quantities of water can be released from the cement suspension to the underground formation. This is the case in particular when the cement suspension flows beyond the porous rock strata during the cementing of the well. The alkalized water that originates from the cement slurry can then cause the clays to swell in the formations and form precipitates of calcium carbonate with carbon dioxide from natural gas or petroleum. As a result of these effects, the permeability of the deposits is reduced and consequently the production rates are also adversely affected.

In addition, as a result of the release of water to the porous underground formations, the cement suspensions do not solidify any longer homogeneously and thus become permeable to gases and liquid hydrocarbons and water. This subsequently leads to the escape of the fossil energy carriers through the annular space filled with porous cement.

Therefore, long-term attempts have been made to reduce such water losses from the cement suspensions used to a tolerable minimum.

EP 0 116 671 A1 describes, for example, a cement suspension for deep wells which is proposed to reduce the loss of water with its content of copolymers. Acrylamides and in particular acrylamidomethylpropanesulfonic acid (AMPS) are an important component of the copolymers used. · According to this document, cement suspensions should contain between 0.1 and 3% by weight of the appropriate copolymers.

EP 1 375 818 A1 relates to the cementing of wells and a composition suitable for this purpose. A polymer additive which, in addition to AMPS, additionally contains maleic acid, N-vinylcaprolactam and 4-hydrolybutyl vinyl ether is used in the same way for the control of fluid loss.

A copolymer according to U.S. Patent 4,015,991 is likewise based on AMPS and partially hydrolyzed acrylamide. The copolymer described in this patent is also said to improve the water retention capacity in cementitious compositions. Well cementation is mentioned as a field of primary use.

US Patent 4,515,635 discloses polymers that are stable to hydrolytic influences and can also be used in well cementation. In the respective uses, the loss of water is said to be reduced by the polymers described. The copolymers substantially comprise N, N-dimethylacrylamide and AMPS. Similar polymers are described in U.S. Patent 4,555,269. The copolymers described herein have a specific relationship between the monomer components of N, -dimethylacrylamide and A PS.

The aforementioned US Patents also relate to compounds that have water retention properties: The water soluble copolymers according to US 6,395,853 Bl contain, inter alia, acrylamides and AMPS. In the foreground of this patent is a process for reducing the loss of water in a suspension that is used to extract oil. The cementing of wells and termination and the drilling mud that precedes these process steps are mentioned in particular in this context.

U.S. Patent 4,700,780 focuses on a process for reducing water loss in cement-containing compositions that also comprise defined salt concentrations. The water retention agent is again an AMPS polymer or polymer salt, it being necessary in this case that building blocks of styrene and acrylic acid are also present.

This multiplicity of known copolymers or graft copolymers have, as already briefly discussed, a property profile that differs in each case and has specific advantages and disadvantages, depending on its monomer composition. A general deficiency that is peculiar to most of these ionic polymers is that their water retention effect declines in the presence of divalent salts as typically occurs in seawater that is frequently used to agitate the cement suspensions in the case of wells of oil and gas from the sea and / or at high temperatures above about 90 ° C, it also being possible for a total loss of effect to occur.

As demonstrated above by way of example, intensive attempts have been made for a long time to provide novel molecules or polymers whose water retention capacity is particularly stable in the oil and gas exploration area, so that assume an advantageous price / performance relationship.

Since salt and temperature stability in specific applications is still in need of improvement, the objective in the present invention is to substantially provide novel molecules that are based on tested and tested components and show substantial improvements particularly in the presence of divalent salts and at high temperatures.

This objective is achieved by the characteristics of the independent claims. The dependent claims relate to preferred embodiments.

It was surprisingly found that, in these applications, the uncharged, macromolecular amphiphilic compounds according to the invention have water retention properties that are virtually identical to those of the commercially available reference samples currently, but have no influence disadvantageous about the rheology of suspensions. In addition, excellent temperature stability was found, which ensures the efficiency of water retention agents over a wide range of temperatures. As uncharged molecules, these compounds do not undergo interaction with divalent metal salts.

Compounds of this type are described in the Not Yet Published International Patent Application PCT / EP2009 / 063079 of the inventors of 08.10.2009 with priority of 09.10.2008 as adsorption blockers in mixtures of building material containing cement, aggregates and plasticizers in variable proportions by weight. When used, these compounds prevent unwanted adsorption of the plasticizer on the aggregates used, which are adsorbent with respect to the plasticizer.

The present invention relates to a water retention agent for chemical building systems, comprising at least one amphiphilic, macromolecular compound having structural units of type A, D and E and at least one sequence of DEA in the molecule , obtainable by means of the reaction of isocyanate groups reactive with groups reactive toward isocyanates, characterized in that E represents a structural unit derived from a polyisocyanate having at least two reactive isocyanate groups, D represents a structural unit that is derived from a hydrophobic compound having at least one isocyanate-reactive group, selected from -OH, -NH2 / -COOH, -NH-R *, in which R * represents a branched or straight-chain C2-28 alkyl group (preferably ethyl, propyl, butyl, hexyl (2-ethyl) hexyl, heptyl, octyl, decyl, tridecyl, octadecyl or cyclohexyl) and A represents a structural unit derived from a hydrophilic compound having at least one isocyanate-reactive group, selected from -OH, -NH2, -COOH.

The statement that the structural units A, D and E are "derived" from the. corresponding compounds comprises the possibility that the compounds were reacted with each other but also comprises the possibility that other compounds that react analogously and lead to the same structural units were used for the synthesis.

At the base of the components, these molecules can be prepared very economically. Preferably, the amphiphilic, macromolecular compound contains 3 to 10 structural units of type A, D and E in the molecule, independently selected from each other.

In the context of the present invention, hydrophobic is to be understood as meaning those compounds which, at a temperature of 20 ° C, have a solubility in water (under atmospheric pressure) of less than 1 g / liter of water, preference of less than 0.3 g / liter of water.

According to the invention, those compounds which, at a temperature of 20 ° C, have a solubility in water (under atmospheric pressure) of more than 10 g / liter of water, preferably of more than 30 g / liter of water , they should be considered as being hydrophilic.

Frequently, the amphiphilic, macromolecular compound is present according to one of the structure types In a preferred embodiment of the invention, the structural units of type A, which bypass the structural units of type E, contain ether groups, and the compounds from which they are derived have molecular weights of 400 to 15,000, preferably 1000 to 5000 g / mol.

Preferably, the structural unit A is derived from a polyethylene glycol or methyl polyethylene glycol or a (block / condition) copoly (ethylene / propylene) glycol or the monomethyl ether thereof, which has a solubility in water at 20 ° C of at least 10%. g / liter of water.

Preferably, the structural unit D is derived from a polyisobutenamine and / or polyisobutensuccinic acid or the anhydride thereof.

Preferably, the structural unit E is derived from a trimeric polyisocyanate containing three reactive isocyanate groups, such as, for example, trimeric hexamethylene diisocyanate.

The amphiphilic, macromolecular compound preferably has a molecular weight of 1000 to 100 000, particularly preferably of 5000 to 50 000 and in particular of 10,000 to 30 000 g / mol.

The water retention agent according to the invention is preferably used in the form of an aqueous emulsion having a solids content of more than 30% by weight. However, even when used in "dry form", a residual moisture of a few percent would have to be expected.

Preferably, the water retention agent comprises 31-99% by weight of the (at least one) amphiphilic, macromolecular compound and 69-1% by weight of water. The formulation "of at least one amphiphilic, macromolecular compound" is proposed to express the fact that mixtures of different amphiphilic, macromolecular compounds which in each case by themselves are covered by the above definitions can be presented in the retention agent of water in the meaning of the present invention.

Next, the chemical compounds from which the structural units A, E and D can be derived will be explained in more detail: Structural unit A: Molecules of structure (1 'a) are used from the group consisting of polyalkylene oxide compounds: (the) in which R 1 = is -H or a straight or branched and optionally unsaturated aliphatic hydrocarbon radical having 1 to 12 carbon atoms and a '= is 0 to 250 and b '= is 0 to 250, with the proviso that a 'and b' are chosen as a function of the molar mass so that the polyalkylene oxide compound has a water solubility of at least 10 g / 1 at 20 ° C.

Preferably, R'1 in the formula (l'a) represents -CH3 (methyl), -CH2-CH2-CH2-CH3 (n-butyl), CH = CH2- (vinyl) and CH2 = CH-CH2- ( allyl), particularly preferably -CH3. The ethylene or propylene units can be distributed similar to block or randomly.

Preferably, a 'is between 20 and 200, particularly preferably between 20 and 150, and b' is between 0 and 20, particularly preferably between 0 and 10. Methylpolyethylene oxides which are commercially available, for example, under the names Commercial Polyglykol M or Pluriol® A are particularly preferred.

In addition, the polyoxyalkylene compounds of the formulas (l'b) and (l'c) are suitable: (l'c) These are commercially available, for example under the trade names Jeffamine® M-1000 or Jeffamine ED-600. '3 Here : R'2 denotes -H, -CH3, c ', f' denote an integer from 1 to 100, also independently of each other, d ', e', g 'denote an integer from 0 to 100, also dependently between sir with the proviso that the ratios c '/ d' and f '/ (e' + g ') are chosen so that the compound has a solubility in water of at least 10 g / 1 at 20 ° C.

Structural unit D: The polyisobutene derivatives that can be prepared by the functionalization of olefinically terminated polyisobutenes. The polyisobutenoamines, polyisobutene succinates and polyisobutene phenols are suitable here. These functionalized polyisobutenes are commercially available, for example, under the name erocom® PIBA (polyisobutenoamine) and Glissopal® SA (polyisobutene succinate). Preferably, polyisobutenoamine or polyisobutenesuccinic acid is used, particularly preferably having an average molar mass of 300 to 3000 g / mol.

Alkyl polyoxyalkylene derivatives, such as, for example, methylpropylene glycols having average molar masses of > 800 g / mol and analogous butyl polyoxypropylene derivatives. In addition, methylpolyoxyalkylene derivatives which are composed of polyoxyethylene and polyoxypropylene units which can be randomly arranged or block-like have been found useful. The molar ratio of oxyethylene to oxypropylene units is chosen so that the resulting alkyl polyoxyalkylene glycols have a solubility in water of less than 1 g / 1 at 20 ° C.

The tetramerbutene derivatives that can be obtained by the functionalization of butene tetramer. The butene tetramer succinic acid, butenol tetramer and butadiene tetramer are preferably used, particularly preferably butenol tetramer.

Fatty acids or mixtures of fatty acids, such as, for example, wood pulp oil fatty acid, stearic acid, palmitic acid, sunflower oil fatty acid, coconut oil fatty acid (Cs-is) fatty acid of coconut oil (Ci2-ie) fatty acid of soybean oil, fatty acid of flaxseed oil, dodecanoic acid, oleic acid, linoleic acid, fatty acid of palm kernel oil, fatty acid of palm oil, linolenic acid and / or arachidonic acid. The fatty acid of wood pulp oil and stearic acid will be considered as being preferred here.

Alkyl alcohols which have a low solubility in water or are insoluble in water and are from the group consisting of C & amp; 2e alcohols, such as, for example, 1-eicosanol, 1-octadecanol, 1-hexadecanol, 1-tetradecanol , 1-dodecanol, 1-decanol, 1-octanol and 1-hexanol, where 1-octanol and 1-decanol and 1-dodecanol are to be considered as being preferred.mo.

N-alkylamines which have a low solubility in water or are insoluble in water, such as, for example, N-butylamine, N-pentylamine, N-hexylamine, N-octylamine, N-decylamine and N-tridecylamine. N-Hexylamine and N-octylamine are preferably used.

N, N-Dialkylamines having low solubility in water or are insoluble in water, such as, for example, N, -ethylhexylamine, N, -dibutylamine, N, N-dipentylamine, N, N-dihexylamine, N, N- dioctylamine, N, (-2-ethylhexyl) amine, N-methyl-N-octadecylamine and N, -didecylamine. N, N-ethylhexylamine and N, -dipentylamine are preferred here.

Polydimethylsiloxanes of the general formula (ll'a): in which denotes -CH, -NH2, -SH, - HR'3, R'3 denotes -H, -CH3, -C2H5, n denotes 1 to 50, preferably 10 to 30 and 'denotes 1 to 6.

Perfluoroalkylethanes of the general formula R'4_CH2-CH2-OH, where the radical R'4 = CF3 (CF2) i'-, in which l 'represents an integer from 6 to 18. Mixtures having different radicals are preferred. R; the commercially available perfluoroalkylethanol Fluowet® EA 612 is used particularly preferably.

Structural unit E: Polyfunctional isocyanates known to the person skilled in the art by the name "coating polyisocyanates" and based on bis (4-isocyanatocyclohexyl) methane (Hi2MDI), 1,6-diisocyanatohexane (HDI), l-isocyanato-5-isocyanatomethyl are used 3, 3, 5-trimethyl-cyclohexane (IPD).

The modified polyisocyanates, which are obtainable, for example, by the hydrophilic modification of the "coating polyisocyanates" based on 1,6-diisocyanatohexane (HDO).

The l-isocyanato-5-isocyanatomethyl-3, 3, 5-trimethyl-cyclohexane (IPDI), bis (4-isocyanatocyclohexyl) methane (H12MDI) 1,3-bis (1-isocyanato-l-methylethyl) benzene (m- TMXDI), 1,6-diisocyanatohexane (HDI) and the higher homologs thereof or industrial isomer mixtures of the individual aliphatic polyisocyanates are preferably used from the group consisting of the aliphatic polyisocyanate compounds, while in particular 2.4 - Disocyanatotoluene (TDI), bis (4-isocyanatophenyl) methane (MDI) and optionally the higher homologs thereof (polymeric MDI) or mixtures of industrial isomers of the individual aromatic polyisocyanates are preferably used from the group consisting of the aromatic polyisocyanates . HDI trimers, which are commercially available under the name Desmodur® N3600 or Desmodur® N3400, are particularly preferably used.

The present invention furthermore relates to a process for the preparation of an amphiphilic, macroraolecular compound according to the above definition which is suitable as a water retention agent, characterized in that a polyisocyanate having at least two reactive isocyanate groups , a hydrophobic compound having at least one isocyanate-reactive group, selected from -OH, -NH2, -COOH, -NH-R *, wherein R * represents a branched or straight C2-28 alkyl group , and a hydrophilic compound having at least one isocyanate-reactive group, selected from -OH, -NH2, COOH, are reacted with each other, provided that the reaction of the components is effected by the reaction of the groups of isocyanates reactive with the groups reactive toward isocyanates.

This preparation can be carried out by a process in which first the individual component according to the structural unit E is reacted with the individual component according to the structural unit A and the obtained reaction product is then reacted with the individual component according to structural unit D. Alternatively, however, it is also possible first for E to be reacted with D and then the reaction product that is reacted with A.

The equivalent ratio of NCO / μ, based on the free groups reactive toward isocyanates (μ = -OH, -NH 2, -NH-R *, -COOH), can be varied within wide limits. According to a preferred embodiment, however, the polyisocyanate compound is used in such an amount that the equivalent ratio of NCO / μ, based on the free groups μ reactive towards isocyanates, in the reaction product of the isocyanate component according to E and the reactive component according to A is 1.0 to 3.0. the equivalent ratio of NCO / μ based on the free groups μ reactive towards isocyanates, in the reaction product of the reactive component according to D is 0.3 to 2.0 or what the equivalent ratio of NCO / μ, based on the free groups μ reactive towards isocyanates, in the reaction product with the isocyanate component according to E and the reactive component according to D is 1.0 to 3.0 the equivalent ratio of NCO / μ, based on the free groups μ reactive toward isocyanates, in the reaction product with the reactive component according to A is 0.5 to 2.0.

The reaction can also be carried out as follows: The reaction of the polyisocyanate component according to E with a hydrophilic component according to A without a solvent in the temperature range of 20 to 150 ° C, the subsequent addition of hydrophobic component according to D at temperatures of 20 to 150 ° C and the final reaction of the reaction product with the component according to A at temperatures of 20 to 150 ° C; or the reaction of the polyisocyanate component according to E with a hydrophobic component according to D without a solvent in the temperature range of 20 to 150 ° C Y the final reaction of the reaction product with the component according to A at temperatures of 20 to 150 ° C.

Preferably, the reaction of the diisocyanate component according to E with the reactive component according to A and / or D is carried out at temperatures of 20 to 150 ° C, it being possible for the reaction to be optionally carried out in the presence of a catalyst. Thus, it has proven to be particularly advantageous to depend on catalysts, such as, for example, dibutyltin dilaurate (T12-DBTL), on the reaction of the isocyanate component according to E with the reactive components according to A and / or D.

If the amphiphilic, macromolecular compound contains at least two structural units of type A, D and / or E in the molecule, it can be said that A, D and / or E can in each case be identical or different.

It has been found that the amphiphilic, macromolecular compound according to the above definition exhibits a remarkable effect as a water retention agent. For this reason, the present invention also relates to the use of this compound as a water retention agent in chemical construction systems and in the development, exploitation and completion of underground deposits of oil and natural gas and in deep wells.

The compound is preferably used as an additive for inorganic binders, in particular hydraulic ones, especially in the offshore sector.

The present invention furthermore relates to a mixture of building material containing 31 to 98% by weight of an inorganic binder, 0 to 68% by weight of aggregate and 0.005 to 5% by weight, in particular 0.05 to 1% by weight , of the amphiphilic, macromolecular compound according to the above definition.

The inorganic binder is preferably present as cement. The aggregate is preferably present in the form of sand, gravel and / or stones.

The present invention further relates to a formulation of construction material containing water and the mixture of building material, preferably in the form of a cement suspension, in particular having a water / cement value of 0.4 to 0.6.

Finally, a structure produced with the use of this formulation of construction material is claimed.

In summary, it can be established that the proposed amphiphilic, macromolecular compound is remarkably suitable as a water retention agent, in particular due to the small influence on the rheology of the well cement suspensions and the significantly increased temperature stability in the range above about 90 ° C and due to its insensitivity to divalent metal salts.

The present invention is now explained in more detail with reference to the following examples: Eg emplos Preparation example 1 (FLA 1) 12. 70 g of trimeric hexamethylene diisocyanate (Desmodur® N3600) are initially taken with 0.08 g of dibutyltin dilaurate (T-12 DBTL) at 55 ° C in a three-neck glass flask having an addition funnel, stirrer and connection inert gas. 115.70 g of hot methyl polyethylene glycol having an average molecular mass of 5000 g / mol are added dropwise with stirring within 20 minutes. Then, the stirring is carried out for 25 min at 60-65 ° C and 12.34 g of polyglycol of B01 / 20 (propylene glycol monobutyl ether, commercial product of Clariant AG) then dosed within 20 min. 9.26 g of polyethylene glycol having an average molar mass of 600 g / mol are now added, and the reaction mixture is then heated to 80 ° C and stirred for an additional 4 hours at this temperature. Then, the reaction product is introduced into 305 g of water and emulsified with stirring. A milky white emulsion having a solids content of 33% by weight is obtained.

Preparation example 2 (FLA 2) 17. 76 g of trimeric hexamethylene diisocyanate (Desmodur® N3600) are initially taken with 0.08 g of dibutyltin dilaurate (T-12 DBTL) at 40 ° C in a 250 ml three neck glass flask having an addition funnel, stirrer and inert gas connection. 97.1 g of hot methyl polyethylene glycol having an average molar mass of 3000 g / mol are added dropwise with stirring within 20 minutes. Then, stirring is carried out for 25 min at 45-50 ° C and 34.2 g of Keroconm® PIBA 03 (polyisobutenoamine, commercial product of BASF SE) then dosed within 20 min. 12.9 g of polyethylene glycol having an average molar mass of 600 g / mol are now added, and the reaction mixture is then heated to 80 ° C and stirred for an additional 4 hours at this temperature. Then, the reaction product is introduced into 330 g of water and emulsified with stirring. A milky white emulsion having a solid content of 33% by weight is obtained.

Preparation example 3 (FLA 3) 17. 71 g of trimeric hexamethylene diisocyanate (Desmodur® N3600) are initially taken with 0.08 g of dibutyltin dilaurate (T-12 DBTL) at 48 ° C in a 250 ml three-necked glass flask having an addition funnel, stirrer and inert gas connection. 96.80 g of hot methyl polyethylene glycol having an average molar mass of 3000 g / mol are added dropwise with stirring within 12 minutes. Then, the stirring is carried out for 25 min at 60-65 ° C and 25.81 g of polyglycol of B01 / 20 (propylene glycol monobutyl ether, commercial product of Clariant AG) then dosed within 20 min. 9.68 g of polyethylene glycol having an average molar mass of 600 g / mol are now added, and the reaction mixture is then heated to 80 ° C and stirred for an additional 4 hours at this temperature. Then, the reaction product is introduced into 305 g of water and emulsified with stirring. A milky white emulsion having a solid content of 33% by weight is obtained.

Example of use 1 Fluid loss was determined in accordance with API Recommended Practice 10B at 60 and 88 ° C (140 and 190 ° F) in the next suspension. The results are reproduced in Table 1, the reference made here in particular to the very low viscosity of the cement suspension formulated with the water retention agent FLA 1 according to the invention: 800 g of cement (class H) 352 g of distilled water 0. 5% by weight of dispersant1 Melcret® 2F2 1 ml of tributyl phosphate (antifoam) 0. 5% by weight of water retention agent1 FLA 1 or reference polymer3 Table 1 FANN 35 molecule, rpm Loss percent by weight of solid, based on the weight of cement taken 2 commercial product of BASF SE commercially available fluid loss additive Polytrol® FL 32 (commercial product of BASF SE) Example of use 2 The loss of fluid was determined in accordance with API Recommended Practice 10B at 60 and 88 ° C (140 and 190 ° F) in the following suspension; the results are reproduced in Table 2: 500 g of cement (class H) 250 g of distilled water 175 g of sand 1 ml of tributyl phosphate (antifoam) Reference polymer2 or polymer according to the invention, for dose, see Table 2 Table 2 1 Percent by weight of solid, based on the weight of cement taken 2 Commercially available fluid loss additive Polytrol® FL 32 (commercial product of BASF SE).

Claims (19)

1. Water retention agent for chemical building systems, comprising at least one amphiphilic, macromolecular compound having structural units of type A, D and E and at least one sequence of DEA in the molecule, obtainable by means of the reaction of isocyanate groups reactive with groups reactive toward isocyanates, characterized in that E represents a structural unit derived from a polyisocyanate having at least two reactive isocyanate groups, D represents a structural unit that is derived from a hydrophobic compound having at least one isocyanate-reactive group, selected from -OH, -NH2, -COOH, -NH-R *, wherein R * represents an alkyl group of C2-28 of branched or straight chain, and A represents a structural unit derived from a hydrophilic compound having at least one isocyanate-reactive group, selected from -OH, -NH2, -COOH.

2. The water retention agent according to claim 1, characterized in that the amphiphilic, macromolecular compound has 3 to 10 structural units of type A, D and E in the molecule, independently selected from each other.

3. The water retention agent according to claim 1 or 2, characterized in that the amphiphilic, macromolecular compound is present according to one of the structure types

4. The water retention agent according to claim 3, characterized in that the structural units of the type A, which bypass the structural units of the type E, contain ether groups, and the compounds from which they are derived have molecular weights of 400 to 15. 000, preferably from 1000 to 5000, g / mol.

5. The water retention agent according to any of claims 1 to 4, characterized in that the structural unit A is derived from a polyethylene glycol, a methylpolyethylene glycol, a (block / state) copoly (ethylene / propylene) glycol or the monomethyl ether of the same, which has a solubility in water at 20 ° C of at least 10 g / 1.

6. The water retention agent according to any of claims 1 to 5, characterized in that the structural unit D is derived from polyisobutenoamine and / or from polyisobutenesuccinic acid.

7. The water retention agent according to any of claims 1 to 6, characterized in that the structural unit E is derived from a trimeric polyisocyanate containing three reactive isocyanate groups.

8. The water retention agent according to any of claims 1 to 7, characterized in that the amphiphilic, macromolecular compound has a molecular weight of 1000 to 100 000, preferably of 5000 to 50 000 and in particular of 10,000 to 30 000 g / mol

9. The water retention agent according to any of claims 1 to 8, characterized in that it comprises 31-99% by weight of the amphiphilic, macromolecular compound and 69-1% by weight of water.

10. Process for the preparation of an amphiphilic, macromolecular compound suitable as a water retention agent, according to the definition of any of claims 1 to 8, characterized in that a polyisocyanate having at least two isocyanate reactive groups, a hydrophobic compound having at least one isocyanate-reactive group, selected from -OH, -NH2, -COOH, -NH-R *, wherein R * represents a branched or straight C2-28 alkyl group, Y a hydrophilic compound having at least one isocyanate-reactive group, selected from -OH, -NH2, -COOH. , they are reacted with each other, with the proviso that the reaction of the components is effected by the reaction of the isocyanate groups reactive with the groups reactive towards isocyanates.

11. Use of an amphiphilic, macromolecular compound according to the definition of any of claims 1 to 8, characterized in that it is as a water retention agent in chemical construction systems and in the development, exploitation and completion of underground oil deposits and natural gas and in deep wells.

12. The use according to claim 11, characterized in that it is as an additive for inorganic binders, in particular hydraulic ones.

13. The use according to any of claims 11 and 12, characterized in that it is for the cementing of oil and gas wells, preferably in the offshore sector.

14. Mixture of construction material, characterized in that it contains 31 to 98% by weight of an inorganic binder, 0 to 68% by weight of aggregate and 0. 005 to 5% by weight, and in particular 0.05 to 1% by weight, of an amphiphilic, macromolecular compound suitable as a water retention agent, according to the definition of any of claims 1 to 8.

15. The construction material mixture according to claim 14, characterized in that the inorganic binder is present as cement.

16. The mixture of construction material according to claim 14 or 15, characterized in that the aggregate is present in the form of sand, gravel and / or stones.

17. Formulation of construction material, characterized in that it contains water and a mixture of construction material according to any of claims 14 to 16.

18. A construction material formulation according to claim 17, characterized in that it is in the form of a cement suspension, in particular having a water / cement value of 0.4 to 0.6.

19. Structure produced with the use of a construction material formulation in accordance with claim 17 or 18.