EP2539385A1

EP2539385A1 - Macromolecular amphiphilic compounds as water retention agents for construction chemical systems, especially for cementing of boreholes

Info

Publication number: EP2539385A1
Application number: EP11701137A
Authority: EP
Inventors: Yulia Fogel; Mario Vierle; Andrea Assmann; Mathias Bauer; Gerhard Albrecht
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2010-02-24
Filing date: 2011-01-27
Publication date: 2013-01-02
Also published as: CA2786829A1; MX2012009677A; WO2011104061A1; EA201201172A1; AU2011220013A1; CN102762624A; AU2011220013B2

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

Macromolecular, amphiphilic compounds as water retention agents for construction chemical systems, in particular for well cementing

The present application claims the benefit of priority to pending US Provisional Patent Application No. 61 / 307,462, dated Feb. 24, 2010, which is incorporated by reference in its entirety.

The present invention relates to a water retention agent for construction chemical systems, a process for the preparation of a suitable as water retention agent macro-molecular, amphiphilic compound, the use of this compound as a water retention agent in construction chemical systems and in the development, exploitation and completion of underground oil and gas deposits and deep drilling , a building material mixture containing this compound, a Baustoffrezeptur containing water and said building material mixture, and a building made using this Baustofempfzeptur.

In the construction chemical field, various copolymers are often used as water retention agents, which are also referred to as fluid loss additives. A special field of application in this context is the cementation of boreholes in the development, exploitation and completion of underground oil and gas deposits as well as in deep wells.

Water retention agents or fluid loss additives have the task of reducing the release of water from a cement slurry. This is of particular importance in the field of oil and natural gas exploration, as cement slurries consisting essentially of cement and water are pumped through the annulus between the so-called casing and the borehole wall during the cementing of the boreholes. In this case, quantities of water can be released from the cement slurry to the subsoil formation. This is particularly the case when the cement slurry flows past porous rock layers during well cementing. The alkalized water originating from the cement slurry can then swell clays in the formations and form calcium carbonate precipitates with carbon dioxide from the natural gas or petroleum. These effects reduce the permeability of the deposits and, as a consequence, the production rates are negatively affected.

In addition, the cement slurries solidify by the discharge of water to the porous subsoil formations no longer homogeneous and thereby permeable to gases and liquid hydrocarbons and water. As a result, this leads to the escape of fossil fuels through the filled with porous cement annulus.

For a long time, therefore, efforts have been made to reduce such water losses of the cement slurries used to a tolerable minimum. In EP 0 1 16 671 A1, for example, a cement slurry for deep wells is described, which is intended to reduce the water loss with its content of copolymers. An important component of the copolymers used are acrylamides and in particular acrylamido-methylpropanesulfonic acid (AMPS). According to this document, the cement slurries should contain between 0.1 and 3% by weight of the suitable copolymers.

Borehole cementing and a composition suitable for this purpose is the subject of EP 1 375 818 A1. Also for fluid loss control, a polymer additive is used which in addition to AMPS additionally contains maleic acid, N-vinylcaprolactam and 4-hydroxybutyl vinyl ether.

Also based on AMPS and partially hydrolyzed acrylamide is a copolymer according to US 4,015,991. The copolymer described in this patent is also intended to improve the water retention capacity in cementitious compositions. The primary field of application is the cementing of boreholes.

US Pat. No. 4,515,635 describes polymers which are stable to hydrolytic influences and can also be used in well treatment. In the respective cases of use, the loss of water should be reduced by the polymers described. The copolymers consist essentially of N, N-dimethylacrylamide and AMPS. Similar polymers can be found in US Pat. No. 4,555,269. The copolymers described here have a specific ratio between the monomer components Ν, Ν-dimethylacrylamide and AMPS.

The US patents listed below also relate to compounds having water retention properties. The water-soluble copolymers according to US Pat. No. 6,395,853 B1 contain inter alia. Acrylamides and AMPS. At the forefront of this right is a process for reducing the loss of water in a slurry used for the extraction of petroleum. Particularly well-known in this context are the well cementing and completion as well as the wellbore sludge preceding these process steps.

The focus of US 4,700,780 is a method of reducing water loss in cementitious compositions which also include defined salt concentrations. The water retention agent is again a polymer or polymer salt of AMPS, in which case the building blocks styrene and acrylic acid still have to be present. This variety of known co- or graft polymers, as already briefly mentioned, depending on their monomer composition, each have a different property profile with specific advantages and disadvantages. A common weakness inherent in most of these ionic polymers is that their water retention action is in the presence of divalent salts, such as those typically found in seawater, which are often used to agglomerate cement slurries in offshore oil and gas wells, and / or or at high temperatures above about 90 ° C, whereby a total loss of efficiency may occur. As demonstrated above by way of example, attempts have long been made intensively to provide new molecules or polymers whose water retention capacity is stable, in particular in the field of oil and gas exploration, so that an advantageous price / performance ratio can be assumed. Since salt and temperature resistance still require improvement in specific applications, the object of the present invention is essentially to provide novel molecules which are based on proven components and show significant improvements, especially in the presence of divalent salts and at high temperatures ,

This object is achieved with the features of the independent claims. The dependent claims relate to preferred embodiments.

It has surprisingly been found that the macromolecular amphiphilic, uncharged compounds according to the invention in these applications have virtually identical water retention properties as currently commercially available reference patterns, but do not exert any adverse effect on the rheology of the sludges. Furthermore, excellent temperature stability was found, which ensures effectiveness of the water retention agents over a wide temperature range. As uncharged molecules, these compounds are not subject to interaction with salts of divalent metals.

Compounds of this type are described in our not yet published international patent application PCT / EP2009 / 063079 from 08.10.2009 with priority from 09.10.2008 as Adsorptionsblocker in building material mixtures containing in varying proportions by weight of cement, aggregates and superplasticizer. These compounds prevent in the application of an undesirable adsorption of the superplasticizer to the adsorptive additives used over the superplasticizer. An object of the present invention is a water retention agent for construction chemical systems comprising at least one macromolecular, amphiphilic compound having structural units of type A, D and E and at least one DEA sequence in the molecule, obtainable by reaction of reactive isocyanate groups with

Isocyanate-reactive groups, characterized in that

E represents a structural unit derived from a polyisocyanate having at least two reactive isocyanate groups,

D represents a structural unit derived from a hydrophobic compound having at least one isocyanate-reactive group selected from -OH, -NH 2, -COOH, -NH-R ^* , where R ^{* is} a branched or unbranched C 2-8 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, -IM H2, -COOH.

The statement that the structural units A, D and E are "derived" from the corresponding compounds, although the possibility that said compounds were reacted with each other, but also includes the possibility that other, analogously reacting compounds that belong to the same structural units used for synthesis. Due to the said components, these molecules can be produced very economically. Preferably, the macromolecular, amphiphilic compound contains 3 to 10 independently selected structural units of the type A, D and E in the molecule. As hydrophobic in the context of the present invention, those compounds are to be understood which have a water solubility (at atmospheric pressure) of less than 1 g / liter of water, preferably less than 0.3 g / liter of water at a temperature of 20 ° C. According to the invention, those compounds are considered to be hydrophilic which have a water solubility (at atmospheric pressure) of more than 10 g / liter of water, preferably of more than 30 g / liter of water, at a temperature of 20 ° C. Often, the macromolecular, amphiphilic compound is in accordance with one of the structural types

A A A A

E A E E A E A E

DDDDDD and or

A A A

E A E A E

D D before.

In a preferred embodiment of the invention, the type A structural units bridging type E structural units contain ether groups and the compounds from which they are derived have molecular weights of from 400 to 15,000, preferably from 1,000 to 5,000 g / mol.

The structural unit A is preferably derived from a polyethylene glycol or methylpolyethylene glycol or a (block / stat) copoly (ethylene / propylene) glycol or its monomethyl ether having a water solubility at 20 ° C. of at least 10 g of water.

The structural unit D is preferably derived from a polyisobuteneamine and / or from polyisobutene-succinic acid or its anhydride. Preferably, the structural unit E is derived from a trimeric polyisocyanate containing three reactive isocyanate groups, such as, for example, trimeric hexamethylene diisocyanate.

The macromolecular, amphiphilic compound preferably has a molecular weight of from 1000 to 100,000, particularly preferably from 5000 to 50,000 and in particular from 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 with more than 30% by weight solids content. But even with a use in "dry form" would have to be expected with a residual moisture content of a few percent.

Preferably, the water retention agent comprises 31-99% by weight of the (at least one) macromolecular amphiphilic compound and 69-1% by weight of water. The expression "the at least one macromolecular, amphiphilic compound" is intended to express that mixtures of various macromolecular, amphiphilic compounds, each of which is individually covered by the above definitions, can also be present in the water retention agent in the meaning of the present invention. Below is to be explained in more detail, from which chemical compounds the structural units A, E and D can be derived:

Structural unit A:

From the group of polyalkylene oxide molecules of structure (l'a) find application:

(l'a) where

R ' ¹ = -H or a linear or branched and optionally unsaturated aliphatic hydrocarbon radical having 1 to 12 C atoms and

a '= 0 to 250 as well

b '= 0 to 250,

with the proviso that a 'and b' are chosen as a function of the molecular weight so that the polyalkylene oxide compound at 20 ° C has a water solubility of at least 10 g / l.

Preferably, R ' ¹ in formula (Ia) is -CH ₃ (methyl), -CH ₂ -CH ₂ -CH ₂ -CH ₃ (n-butyl), CH = CH ₂ - (vinyl) and CH ₂ = CH-CH ₂ - (allyl), more preferably -CH ₃ . The ethylene or propylene units may be distributed in blocks or randomly.

Preferably, a 'is between 20 and 200, particularly preferably between 20 and 150, and b' is between 0 and 20, more preferably between 0 and 10. Particularly preferred are methyl polyethylene oxides which are commercially available, for example, under the trade names Polyglycol M or Pluriol® A are available.

Furthermore, polyoxyalkylene compounds of the formula (I'b) and / or (I'c) are suitable:

(I'C)

These are commercially available, for example, under the trade names Jeffamine® M-1000 and Jeffamine® ED-600, respectively.

Where:

R ' ² = -H, -CH ₃ ,

c ', f = an integer from 1 to 100, also independently of one another, d', e ', g' = an integer from 0 to 100, also independently of one another, with the proviso that the ratios c '/ d' and f '/ (e' + g ') are selected so that the compound has a water solubility of at least 10 g / l at 20 ° C.

Structural unit D:

Polyisobutene derivatives obtained by functionalization of olefinically terminated

Polyisobutenes can be prepared. Polyisobuteneamines, polyisobutene succinates and polyisobutenephenols are suitable here. These functionalized

Polyisobutenes are commercially available, for example, under the name Kerocom® PIBA (polyisobuteneamine) and Glissopal® SA (polyisobutene succinate). Preference is given to using polyisobutene-amine or polyisobutene-succinic acid, particularly preferably having an average molar mass of from 300 to 3000 g / mol.

Alkylpolyoxyalkylene derivatives such as methylpolypropylene glycols having average molecular weights> 800 g / mol and analogous Butylpolyoxypropylenderivate. Furthermore, Methylpolyalkoxylenderivate have proven, which are composed of polyoxyethylene and Polyoxypropy- leneinheiten which may be arranged randomly or in blocks. The molar ratio of oxyethylene to oxypropylene units is chosen the resulting alkyl polyoxyalkylene glycols have a water solubility of less than 1 g / l at 20 ° C.

Butene tetramer derivatives which can be obtained by functionalization of tetrameric butene. Preferably tetrambutylsuccinic acid, tetramerbutenol and tetramerbutene diol are used, more preferably tetramerbutenol.

Fatty acids or fatty acid mixtures, such as tall oil fatty acid, stearic acid, palmitic acid, sunflower oil fatty acid, coconut oil fatty acid (Ce-ie), coconut oil fatty acid (C12-18), soybean oil fatty acid, linseed oil fatty acid, dodecanoic acid, oleic acid, linoleic acid,

Palm kernel oil fatty acid, palm oil fatty acid, linolenic acid and / or arachidonic acid. Tall oil fatty acid and stearic acid are considered to be preferred.

Low water-soluble or water-insoluble alkyl alcohols from the group of Ce-28 alcohols, such as, for example, eicosanol, 1-octadecanol, 1-hexadecanol, 1-tetradecanol, 1-dodecanol, 1-decanol, 1-octanol and 1-hexanol, where 1-octanol and 1-cancanol and 1 -dodecanol are to be regarded as preferred.

Low water-soluble or water-insoluble N-alkylamines, for example N-butylamine, N-pentylamine, N-hexylamine, N-octylamine, N-decylamine, and N-tridecylamine. Preference is given to using N-hexylamine and N-octylamine.

Low water-soluble or water-insoluble Ν, Ν-dialkylamines such as N, N-ethylhexylamine, Ν, Ν-dibutylamine, N, N-dipentylamine, Ν, Ν-dihexylamine, N, N-dioctylamine, N, N- (2 ethylhexyl) amine, N-methyl-N-octadecylamine and N, N-didecylamine. Here, Ν, Ν-ethylhexylamine and Ν, Ν-dipentylamine are preferred.

Polydimethylsiloxanes of the general formula (II'a):

(Ll'a)

-OH, -NH ₂ , -SH, -NHR ' ³ ,

1 to 50, preferably 10 to 30, as well

1 to 6 mean. Perfluoralkylethanole the general formula RVCH2-CH2-OH, with the radical R ' ₄ =

CF3 (CF2) r, where Γ represents an integer from 6 to 18. Preference is given to mixtures having different radicals R ' ₄ , particularly preferably the commercially available perfluoroalkylethanol Fluowet® EA 612 is used.

Structural unit E:

Under the name "lacquer polyisocyanates" known to those skilled polyfunctional isocyanates based on bis (4-isocyanatocyclohexyl) methane (H12MDI), 1, 6-diisocyanatohexane (HDI), 1-isocyanato-5-isocyanatomethyl-3,3 , 5-trimethyl-cyclohexane (IPDI) used.

Modified polyisocyanates, which are accessible for example by hydrophilic modification of "paint polyisocyanates" based on 1, 6-diisocyanatohexane (HDI).

Preference is given from the group of aliphatic polyisocyanate compounds 1-isocyanato-5-isocyanatomethyl-3,3,5-trimethyl-cyclohexane (IPDI), bis (4-isocyanato-cyclohexyl) -methane (H12MDI), 1, 3-bis- (1-isocyanato-1-methyl-ethyl) -benzene (m-TMXDI), 1, 6-diisocyanatohexane (HDI), and its higher homologues or technical isomer mixtures of the individual aliphatic polyisocyanates used, while from the group of aromatic polyisocyanates in particular 2,4-diisocyanatotoluene (TDI), bis (4-isocyanatophenyl) -methane (MDI) and optionally its higher homologs (polymer MDI) or technical isomer mixtures of the individual aromatic polyisocyanates are preferably used. Particular preference is given to using HDI trimers which are commercially available under the name Desmodur® N3600 or Desmodur® N3400.

Another object of the present invention is a process for preparing a macromolecular, amphiphilic compound suitable as a water retention agent as defined above, 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 ^* , where R ^{* represents} a branched or unbranched C2-28-alkyl group, and a hydrophilic compound having at least one isocyanate-reactive group, selected from -OH, -NH2, - COOH, are reacted with the proviso that the reaction of the components by reaction of the reactive isocyanate groups with the isocyanate-reactive groups takes place. This preparation can be carried out in such a way that initially the individual component corresponding to the structural unit E is reacted with the individual component corresponding to the structural unit A and the reaction product obtained is then reacted with the zelkomponente corresponding to the structural unit D is implemented. Alternatively, however, it is also possible first to react E with D and then to react the reaction product with A. The NCO ^ equivalent ratio with respect to the free isocyanate-reactive groups (μ = -OH, -Nh, -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 NCO ^ equivalent ratio with respect to the free isocyanate-reactive groups μ in the reaction product of isocyanate component corresponding to E and the reactive component corresponding to A 1, 0 to 3.0 is the NCO Equivalent ratio with respect to the free isocyanate-reactive groups μ in the reaction product with the reactive component corresponding to D is 0.3 to 2.0

or that

the NCO ^ equivalent ratio with respect to the free isocyanate-reactive groups μ in the reaction product of isocyanate component corresponding to E and the reactive component corresponding to D 1, 0 to 3.0 is - the NCO ^ equivalent ratio with respect to the free isocyanate-reactive groups μ in the reaction product the reactive component corresponding to A is 0.5 to 2.0

The reaction can also be carried out as follows:

Reaction of the polyisocyanate component corresponding to E with a hydrophilic component corresponding to A without solvent in the temperature range from 20 to 150 ° C, followed by addition of the hydrophobic component corresponding to D at temperatures of 20 to 150 ° C and

Ready reaction of the reaction product with the component corresponding to A at temperatures of 20 to 150 ° C;

or

Reaction of the polyisocyanate component corresponding to E with a hydrophobic component corresponding to D without solvent in the temperature range from 20 to 150 ° C and

Final reaction of the reaction product with the component corresponding to A at temperatures of 20 to 150 ° C.

Preferably, the reaction of the isocyanate component corresponding to E with the reactive component corresponding to A and / or D takes place at temperatures of 20 to 150 ° C, wherein the reaction can optionally take place in the presence of a catalyst. Thus, it has proved to be particularly advantageous in the reaction of the isocyanate component speaking to use E with the reactive components corresponding to A and / or D on catalysts such as dibutyltin dilaurate (T12-DBTL).

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

It has been found that the macromolecular, amphiphilic compound as defined above shows excellent activity as a water retention agent. For this reason, another object of the present invention is the use of this compound as a water retention agent in construction chemical systems and in the development, exploitation and completion of underground oil and gas deposits and deep drilling.

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

Another object of the present invention is a building material mixture containing 31 to 98 wt .-% of an inorganic binder, 0 to 68 wt .-% aggregate and 0.005 to 5 wt .-%, in particular 0.05 to 1 wt .-%, the macromolecular, amphiphilic compound as defined above.

The inorganic binder is preferably present as a cement. The supplement is preferably in the form of sand, gravel and / or stones. Another object of the present invention is a Baustofempfzeptur containing water and the said building material mixture, preferably in the form of a cement slurry, in particular with a water / cement value of 0.4 to 0.6.

Finally, a building made using this building material recipe is claimed.

In conclusion, the proposed macromolecular, amphiphilic compound is outstandingly useful as a water retention agent, particularly due to the low impact on the rheology of the well cement slurries and the significantly increased temperature stability in the range above about 90 ° C and its insensitivity to salts of divalent metals suitable is.

The present invention will now be explained in more detail with reference to the following examples: Examples

Production Example 1 (FLA 1)

12.70 g of trimeric hexamethylene diisocyanate (Desmodur® N3600) with 0.08 g of di-butyltin dilaurate (T-12 DBTL) are initially introduced at 55 ° C. in a 250 ml three-necked glass flask with dropping funnel, stirrer and inert gas connection. While stirring, 1 15.70 g of methyl polyethylene glycol having an average molecular weight of 5000 g / mol are added dropwise hot within 20 minutes. The mixture is then stirred for 25 min. At 60-65 ° C and then within 20 min. 12.34 g of polyglycol B01 / 20 (polypropylene glycol monobutyl ether, commercial product of Clariant AG) added. Is now 9.26 g of polyethylene glycol having an average molecular weight of 600 g / mol, then the reaction mixture is heated to 80 ° C and stirred for a further 4 h at this temperature. Subsequently, the reaction product is introduced into 305 g of water and emulsified with stirring. This gives a milky white emulsion having a solids content of 33 wt .-%.

Production Example 2 (FLA 2)

17.76 g of trimeric hexamethylene diisocyanate (Desmodur® N3600) with 0.08 g of di-butyltin dilaurate (T-12 DBTL) are initially introduced at 40 ° C. into a 250 ml three-necked glass flask with dropping funnel, stirrer and inert gas connection. While stirring, 97.1 g of methyl polyethylene glycol having an average molar mass of 3000 g / mol are added dropwise hot within 20 minutes. The mixture is then stirred for 25 min. At 45-50 ° C and then added within 20 min. 34.2 g Kerocom® PIBA 03 (polyisobutenamine, commercial product of BASF SE) added. 12.9 g of polyethylene glycol having an average molecular weight of 600 g / mol are then added, and the reaction mixture is subsequently heated to 80 ° C. and stirred for a further 4 hours at this temperature. Subsequently, the reaction product is introduced into 330 g of water and emulsified with stirring. This gives a milky white emulsion having a solids content of 33 wt .-%. Production Example 3 (FLA 3)

17.71 g of trimeric hexamethylene diisocyanate (Desmodur® N3600) with 0.08 g of di-butyltin dilaurate (T-12 DBTL) are initially charged at 48 ° C. in a 250 ml three-necked glass flask with dropping funnel, stirrer and inert gas connection. While stirring, 96.80 g of methyl polyethylene glycol having an average molar mass of 3000 g / mol are added dropwise hot within 12 minutes. The mixture is then stirred for 25 min. At 60-65 ° C and then within 20 min. 25.81 g of polyglycol B01 / 20 (polypropylene glycol monobutyl ether, commercial product of Clariant AG) added. 9.68 g of polyethylene glycol having an average molar mass of 600 g / mol are then added, the reaction mixture is subsequently heated to 80 ° C. and stirred for a further 4 hours at this temperature. Subsequently, the reaction product is introduced into 305 g of water and emulsified with stirring. This gives a milky white emulsion having a solids content of 33 wt .-%. Application example 1

The fluid loss was determined according to API Recomended Practice 10B at 140 and 190 ° F (60 and 88 ° C) in the following slurry. The results are reproduced in Table 1, wherein in particular the very low viscosity of the cement slurry formulated with the water retention agent FLA 1 according to the invention should be indicated: 800 g of cement (class H)

352 g of distilled water

0.5% by weight dispersant ¹ Meieret® K2F ²

1 ml tributyl phosphate (defoamer)

0.5% by weight of water retention agent ¹ FLA 1 or reference polymer ³

Table 1

¹ weight percent solids based on the weight of the cement

2 Commercial product of BASF SE

³ Commercially available fluid loss additive Polytrol® FL 32 (commercial product of BASF SE)

Application Example 2

The fluid loss was determined according to API Recomended Practice 10B at 140 and 190 ° F (60 and 88 ° C) in the following slurry; the results are given in Table 2: 500 g of cement (class H)

250 g of distilled water

175 g of sand

1 ml tributyl phosphate (defoamer)

Reference polymer ² or polymer according to the invention, dosages see Table 2 Table 2

¹ weight percent solids based on the weight of the cement

2 Commercially available fluid loss additive Polytrol® FL 32 (commercial product of BASF SE)

Claims

claims

1 . Water retention agent for construction chemical systems, comprising at least one macromolecular, amphiphilic compound having structural units of type A, D and E and at least one D-E-A sequence in the molecule, obtainable by reacting reactive isocyanate groups with isocyanate-reactive groups, characterized in that

D represents a structural unit derived from a hydrophobic compound having at least one isocyanate-reactive group selected from -OH, -NH 2, -COOH, -NH-R ^* , wherein R ^{* represents} a branched or unbranched C 2-8 alkyl group, is derived, and

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

Water retention agent according to claim 1 or 2, characterized in that the macromolecular, amphiphilic compound according to one of the structural types

and or

is present.

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

Water retention agent according to one of claims 1 to 4, characterized in that the structural unit A of a polyethylene glycol, a methylpoly- ethylene glycol, a (ß / oc / </ Sfaf) copoly (ethylene / propylene) glycol or its monomethyl ether having a water solubility at 20 ° C is derived from at least 10 g / l.

Water retention agent according to one of claims 1 to 5, characterized in that the structural unit D is derived from a polyisobuteneamine and / or from polyisobutenesuccinic acid.

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

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

A water retention agent according to any one of claims 1 to 8, comprising

31-99 wt .-% of the macromolecular, amphiphilic compound and

69-1 wt% water.

Process for the preparation of a macromolecular, amphiphilic compound suitable as a water retention agent as defined in any one of claims 1 to 8, 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, - IMH2, -COOH, -NH-R ^* , where R ^{* represents} a branched or unbranched C2-28-alkyl group, and a hydrophilic compound having at least one isocyanate-reactive group selected from -OH, -IMH2, -COOH, with the proviso that the reaction of the components by reaction of the reactive isocyanate groups with the isocyanate-reactive groups takes place. 1 1. Use of a macromolecular, amphiphilic compound as defined in any one of claims 1 to 8 as a water retention agent in construction chemical systems and in the development, exploitation and completion of underground oil and gas deposits and deep boreholes. 12. Use according to claim 1 1 as an additive for inorganic, in particular hydraulic binder.

13. Use according to any one of claims 1 1 or 12 in the cementation of oil and gas wells, preferably in the offshore area.

14. building material mixture containing

31 to 98 wt .-% of an inorganic binder, 0 to 68 wt .-% aggregate and

0.005 to 5% by weight, in particular 0.05 to 1% by weight, of a macromolecular amphiphilic compound suitable as a water retention agent as defined in any one of claims 1 to 8.

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

16. building material mixture according to claim 14 or 15, characterized in that the supplement is in the form of sand, gravel and / or stones.

17. Building material formulation containing water and a building material mixture according to any one of claims 14 to 16. 18. Baustoffrezeptur according to claim 17 in the form of a cement slurry, in particular with a water / cement value of 0.4 to 0.6.

19. Building produced using a Baustoffrezeptur according to claim 17 or 18.