NO178581B - Use of surfactant alkyl glucoside compounds in water- and oil-based drilling muds and other fluid wells for boreholes as well as drilling muds and compounds containing the compounds - Google Patents

Description

The invention relates to the use of selected emulsifiers with increased ecological compatibility for the production of fluid, dispersed systems which are either available as water/oil invert emulsions with a continuous oil phase or as aqueous emulsions with a dispersed oil phase and which are suitable for technical use within the framework of fluid treatment agents for boreholes. As a characteristic example of agents of this type, the invention is described in the following on the basis of oil-based or water-based drilling flushing fluids and drilling mud built up thereon. However, the range of application for the modification according to the invention of auxiliary fluids of the type discussed here is not limited to this. In consideration, especially also the areas of spotting fluids, spacers, auxiliary fluids for overhaul and stimulation and for fracturing.

As indicated above, the invention also relates to drilling mud built up on the drilling fluids.

The invention is thereby particularly based on the task of substantially influencing the ecological acceptability of these aids which are currently in large-scale technical use worldwide by the use of selected and particularly ecologically acceptable emulsifier types. In the preferred embodiment, the invention uses these biologically acceptable emulsifiers at the same time as oil phases with increased environmental compatibility and especially biodegradability.

Within the area of fluid flushing systems for lowering rock borings and raising the drilled cuttings, the so-called invert drilling muds are today very important, which on the basis of water/oil emulsions contain a "dispersed aqueous phase in the continuous oil phase. The content of dispersed phase is usually in the range of about 5 to 50 wt-#.

However, water-based drilling muds with an emulsified dispersed oil phase (oil/water type) whose oil content can vary from a few percent to approx. 50 weight #. Oil/water emulsion muds of this type show a number of significant advantages compared to purely water-based muds.

For stabilization of the dispersion form chosen in each case, the use of corresponding emulsifiers is required, either of the water/oil type (invert sludge) or of the oil/water type (emulsion sludge). For current specialist literature, reference is made, for example, to G.R. Gray, H.C.H. Darley "Composition in Properties of Oil Well Drilling Fluids", 4th edition, Gulf Publishing Co., Houston London, 1981, especially pages 51, 64 and 320 ff.

01jefas of the drilling muds of the type mentioned here and comparably structured other treatment agents for boreholes are formed in practice today almost exclusively from mineral oil fractions. This results in a not insignificant burden on the environment, when, for example, the drilling mud immediately or via the drilled cuttings comes into contact with the environment. Mineral oils are only difficult, and anaerobically practically not, degradable and must therefore be considered as long-term pollution. When these oil phases, also as the main component or at least a significant proportion of the drilling muds, are an important point of reference when it comes to ecological considerations, then the other components of such multi-substance mixtures must also be given corresponding attention. The emulsifiers are of particular importance in this connection. According to their determination, compounds of this type are already in low concentration very active active substances, which, as is known, are capable of intense interaction with vegetable or animal organisms.

The present invention is based on the task of substantially improving working agents of the type mentioned on the basis of continuous or dispersed oil phases in a mixture with aqueous phases, taking into account their ecological compatibility compared to ordinary working agents of this type. The invention will thereby propose emulsifiers or emulsifier components which are known in and of themselves and which are thereby described as environmentally friendly to a high degree, but which have so far not found any application for the work area in question here. In the preferred embodiment of the invention, these environmentally friendly emulsifiers of the water/oil type or of the oil/water type are to be used together with oil/water phases in which the oil phases, in turn, have increased ecological compatibility and can in particular be degraded by natural breaking mechanisms in an environmentally friendly way.

To solve the first part of the problem, the invention proposes, as ecologically compatible or harmless compounds with emulsifying action, to use in and of themselves surface-active alkylglycoside compounds, which, as is known, depending on their constitution and the interaction with the surrounding system, are to be classified as water/oil- emulsifiers or as oil/water emulsifiers.

Accordingly, the present invention relates to the use of surface-active alkylglycoside compounds of the water/oil type with the formula

in which

E means linear and/or branched, saturated and/or unsaturated alkyl with at least 8 C atoms, preferably with 10 to 22 C atoms,

Z means one or more residues of aldoses and/or ketoses, especially hexose and/or pentose units as well as

n on average a number from 1 to 5 and especially from 1.2 to 2.5, as ecologically compatible emulsifiers in fluid and pumpable drilling mud or other fluid treatment agents for boreholes,

which, together with a dispersed aqueous phase, exhibits a continuous and thereby ecologically compatible oil phase and is suitable for environmentally friendly utilization of biological deposits, especially of petroleum and natural gas deposits, whereby in the case of the use of oil phases exposed to hydrolysis, corresponding oils are selected, which also in the case of a partial saponification in practical application does not lead to any toxicological, especially not any inhalation-toxicological danger.

Of particular importance in this context is corresponding invert drilling mud which in a continuous oil phase contains a dispersed aqueous phase together with emulsifiers, further common auxiliaries such as thickeners, fluid-loss additives, ballasts, soluble salts and/or alkali reserves. According to the invention, in this embodiment the use of surface-active alkylglycoside compounds of the water/oil type is foreseen as an emulsifier or at least as a component of an ecologically compatible emulsifier system.

Preferably, these emulsifiers are used on the basis of surface-active alkyl glycoside compounds together with environmentally compatible ester oils, oleophilic alcohols and/or corresponding ethers which closed or dispersed oil phase. Particular reference is made here to the current developments of the applicant, who in a large number of older patent applications describe proposals for the replacement of the previously common mineral oil fractions with ecologically acceptable, easily degradable oil phases. This indicates different types of replacement oils, which can also be used in a mixture with each other. This concerns selected oleophilic monocarboxylic esters, selected polycarboxylic acid esters, at least * primarily water-insoluble, and under the working conditions fluid alcohols, corresponding ethers and selected carboxylic acid esters. In summary, reference is made here to the older applications P912337, P912338, P913239, P913240, P913041, P913098, P913042, P911706, P924224 and P924345. All the older applications mentioned here relate to the area of oil-based drilling mud systems, especially of the water/oil invert type. Water-based emulsion muds using these oil phases with increased degradability are described in the older applications P914110, P913658, P914111 and the already mentioned applications P924224 and P924345. In the most important embodiment, the invention comprises the simultaneous use of the above-mentioned emulsifiers from the class of surface-active alkylglycoside compounds together with dispersed or continuous oil phases of the last-mentioned type. When it comes to details, reference is made to the description in the aforementioned older applications. ;Surface-active alkylglycoside compounds and their preparation are described in detail within the state of the art, whereby admittedly so far the center of gravity has been placed on their use as oil/water emulsifiers - for example in connection with detergents and cleaning agents. Reference is made in this context to DE-Å1 38 33 780 and the primary literature cited therein. A later proposal - see in this connection DE-A1 37 20 330 - envisages the co-use of alkyl glycosides within the framework of so-called tertiary extraction of crude oil from similar deposits. ;Like that, the alkylglycoside compounds used for the purpose of application according to the invention can also be indicated by the general formula (I) ;;where in this formula R has the following meaning: ;Linear and/or branched alkyl which can be saturated and/or olefinically unsaturated and exhibit at least 7 C atoms in the residue R. Corresponding residues R with 8 to 22 C atoms are preferred. ;Z stands for one or more residues of aldoses and/or ketoses, whereby here in particular hexose and/or pentose units come into consideration. ;n characterizes the statistical oligomer distribution formed during the preparation in a known manner for the residue Z. Numerically, n means on average a number from 1 to 10, preferably from 1.5 to approx. 5. Of particular importance are alkylglycoside compounds of general formula (I), in which n means a numerical value in the range from approx. 1.2 to 2.5. The term surface-active alkylglycoside compounds is therefore also used according to the invention for the corresponding reaction products of sugars and monofunctional alcohols. As sugar components, the aldoses designated as glycoses or the ketoses in the broadest sense come into consideration. Mention should be made of glucose, fructose, mannose, galactose, talose, gulose, allose, altrose, idose, arabinose, xylose, lyxose and ribose. Aldoses are preferably used for the production of the alkylglycoside compounds due to their better reactivity. Among the aldoses, due to their easy availability and disposability in technical quantities, glucose is particularly important. The monofunctional alcohols used for acetalization are especially the technically available surfactant alcohols with 8 to 22 C atoms, whereby native and/or synthetic alcohols come into consideration. As is known, native alcohols are obtained from the hydration of fatty acids and fatty acid derivatives. Characteristic synthetic components are the known oxo alcohols and/or Ziegler alcohols. The alcohols themselves can be saturated or also particularly olefinically unsaturated. Straight-chain alcohols are particularly important because of their particularly fast problem-free degradability. Branched alcohols, for example those of the oxo alcohol type, are however to be considered ecologically acceptable components and suitable for the acetalization of alkylglycoside compounds of the type used according to the invention. ;Alkyl glycosides are excellent emulsifier components in connection with the present invention not only because of their biological safety, but as acetals they have, as is known, significant alkali stability. Treatment agents for boreholes of the type mentioned here, especially drilling mud, are usually built up with the co-use of alkali reserves, for example to be able to counteract the intrusion of acidic reactants from the drilled rock. This alkali stability of the alkylglycoside compounds is an essential element for their usefulness in practice. At the same time, they provide - depending on their special structure - very stable water/oil emulsions or equivalent, very stable oil/water emulsions. The arrangement of the emulsifiers in the previously mentioned classes is, in a manner known per se, conditioned by the ratio between the oleophilic parts of the molecule in question and the hydrophilic molecular part. The allocation can therefore take place via the so-called HLB value, whereby, as is well known, the typical water/oil emulsifiers are characterized by relatively low HLB values - for example those in the range from 3 to 11 or 12, while the classic oil/water emulsifiers occupies the higher range of the HLB numerical values. Also in the relevant area of treatment agents for boreholes this classification is used, see in this connection for example the initially cited publication Gray, Darley a.a.O., page 321. ;The preferred functionality in any case of selected alkylglycoside compounds of general formula (I) derives from their structural elements. The oleophilic molecular portion is characterized by the residue R of this formula picture. The sugar fraction Z and here in particular its oligomer distribution - indicated by the statistical numerical value for n - constitutes the hydrophilic molecular proportion. Water/oil emulsifiers of this type are consequently characterized by distinctly oleophilic molecular proportions by limiting the hydrophilic molecular proportion, inverse conditions exist in the case of typical oil/water emulsifiers. Consequently, for the stabilization of water/oil emulsions, such compounds of general formula (I) are particularly suitable which at least partially and preferably predominantly exhibit residues R with 10 or more C atoms, preferably with at least approx. 12 C atoms. Alcohol residues of this type with 16 to 18 C atoms can be of special importance both for technical and economic reasons. At the same time, the statistical mean value n for the usually present glucose residue is limited here to values below approx. 2.5, and preferably to maximum values of approx. 2. In preferred embodiments, n can lie in the range from approx. 1.2 to 1.8. It is a characteristic of the use of the alkylglucoside compounds within the scope of the invention that relatively slight shifts in the molecular structure can strongly affect the suitability for the component(s) in question, whereby it is also characteristic, however, that precisely within the scope of the manufacturing technically interesting compounds there is a relatively wide range of compounds suitable as stabilizing emulsifiers of the water/oil type. Here, the type of emulsion formed is strongly influenced by the overall composition, for example of the relevant drilling fluid or the corresponding drilling mud. The alkylglycoside-based emulsifiers are used in a preferred embodiment as the essential emulsion-type-forming and emulsion-stabilizing components. The teaching according to the invention also includes mixed systems, in which the alkyl glycosides are used with other emulsifier components. Preferably, these other emulsifier components are in turn ecologically acceptable, in this connection reference should be made, for example, to the older DE application 40 03 028 and the applicant's parallel P924725, in which selected emulsifiers on an ether basis or on a di-salt basis are described, especially for oil-based invert emulsions . If such emulsifier mixtures are used, then, in the preferred embodiments of the invention, the alkylglycoside compounds with approx. 10 weight #, preferably at least approx. 50 weight-56 of the relevant emulsifier system. The alkyl glycoside compounds can be used in amounts of approx. 0.1 to 10 wt-#, calculated on the basis of the sum of the liquid phases of water and oil. Preferred amounts are in the range from approx. 0.5 to 5 wt-# of the emulsifier components, whereby the range from approx. 1 to 3 weight # of the emulsifier, again on the basis of water + oil, is of particular importance. Within the framework of the hitherto known production of surface-active alkylglycoside compounds, efforts are made to separate the alcohol used in excess from the acetalization reaction after reaction completion to such a large extent from the acetalization product that at best a few percent of free alcohol remains in the reaction mixture. In this connection, reference should be made to the corresponding specifications in DE-A1 38 33 780 and the method of thin-layer evaporation for alcohol recovery mentioned there for the purpose. The work according to the invention can dispense with this relatively expensive method step. The alcohols R-OE used for acetalization are generally oleophilic alcohol components which are present in excess and in admixture with the formed alkylglycoside or can be added for the intended purpose of use. If desired, the excess alcohol can be partially separated, whereby in a preferred embodiment of the invention, however, it is assumed that the alkyl glycosides are used together with at least approx. 50 mol-56 and preferably together with at least approx. 100 mol% free alcohol mol, the % in each case being stated on the basis of the alkyl glycoside compound. A further relief for the industrial production of the emulsifier according to the invention lies in the fact that bleaching of the primarily formed reaction products can be dispensed with, which according to the published state of the art is considered an essential process step for the production of this class of emulsifier. The manufacturing process for mixtures of active substance containing alkyl glycoside in the sense of the invention can therefore be limited to the manufacturing step with acetalization - appropriately in the presence of acid catalysts. Then only the acid catalyst is neutralized. The resulting reaction product can be immediately added to the technical application. As a form of application for the alkyl glycosides, two significant preparation forms in particular have proven appropriate: On the one hand, the alkyl glycosides can be stored and handled as solution concentrates in preferably ecologically harmless oil phases. Secondly, it is possible to use the alkyl glycosides as solid substances - here especially in granule form. As the emulsifier compounds as such at normal temperature do indeed usually constitute solids, but nevertheless easily show a tendency to stick together and/or float, it may be appropriate to also use particulate solids for corresponding granule formation. Suitable here are typical auxiliaries from crude oil technology with a particulate solid character, for example ballast agents, salts, viscosity formers and the like, or inert auxiliaries can also be used. In the preferred embodiment specifically stated at the outset, the relevant oil phases are formed by the ecologically acceptable ester oils, oleophilic alcohols and/or ethers mentioned in the cited older applications from the applicant. When using these agents, the invention consequently relates to the fluid and pumpable treatment agents for boreholes in the range from 5 to 20°C, especially drilling flushing agents based on either a continuous oil phase, especially in admixture with a dispersed aqueous phase (water/oil invert type) or a dispersed oil phase in a continuous aqueous phase (oil/water emulsion type). As mentioned at the outset, the invention relates to invert drilling mud which is suitable for an environmentally friendly utilization of geological deposits and which in a closed oil phase contains a dispersed aqueous phase together with emulsifiers and usual additional auxiliary substances, for example thickeners, fluid loss additives, ballast agents, water-soluble salts and alkali reserves and this method is characterized by the fact that, together with an ecologically compatible, continuous oil phase, they contain surface-active alkyl glycoside compounds of general formula (I) as emulsifier or emulsifier component. ;The ecologically compatible oils and oil phases cover a wide area with regard to their possible physical nature. On the one hand, the invention includes oil phases which are fluid and pumpable even at lower temperatures. Here are particularly representatives that are suitable for the production of water/oil emulsions. But also highly viscous to solid oil phases or materials of this type can also be used within the scope of the teachings of the invention. Reference is made, for example, to the following considerations. ;For water-based oil/water emulsion sludge, a high mobility of the dispersed oil phase is not required, possibly not even once desired. For example, to ensure good lubrication properties, relatively viscous oil phases can be advantageous. Another possibility for the use of highly viscous or even solid ecologically compatible oil phases is provided when, in any case, the oil phases present in the finished product are only partially formed by these highly viscous to solid representatives of degradable esters, alcohols and/or ethers, which in turn are mixed with relatively thin-flowing oils of this type. For all oil phases or oil mixture phases covered by the invention, however, it uniformly applies that flash points of at least approx. 100°C and preferably flash points above approx. 135°C are required in operation for safety reasons. Values clearly above this, especially those above 150°C, can be particularly appropriate. It also uniformly applies to the various potentially hydrolysis-exposed oil phases, which can be used within the scope of the invention, that the requirement for ecological acceptability does not only apply to the starting compound, i.e. for example to the ester oil or mixture of ester oils chosen in each case, but also that with a partial saponification in practical use, no toxicological and especially no inhalation-toxicological hazard is triggered. It is within the framework of the aforementioned older applications described in detail that the various representatives of ester oils are particularly touched upon here, whereby here again monofunctional alcohols from ester formation acquire special importance. Monofunctional alcohols are, compared to polyfunctional alcohols, highly volatile in the lower parts, so that in the case of partial hydrolysis, a secondary hazard can occur here. Consequently, in the classes of different ester oils, monofunctional alcohols and the corresponding residues of these alcohols are preferably chosen in such a way that they have at least 6 C atoms in the molecule, preferably at least 8 C atoms. For invert drilling mud of the type relevant according to the invention, regardless of the specific nature of the closed oil phase, it applies that in preferred embodiments they exhibit a plastic viscosity (PV) in the range from approx. 10 to 60 mPas and a yield point (Yield Point YP) in the range of 5 to 40 lb/100 ft<2> (0.244 to 1.95 kg/m2 ) -all times determined at 50°C. As ecologically acceptable and at lower temperatures good fluid oil phase, especially the ester oils of monocarboxylic acids have been shown, which in a preferred embodiment of the invention are derived from at least one of the following subclasses: a) Esters of C^_5-monocarboxylic acids and en- and/ or polyfunctional alcohols, whereby the residues from monohydric alcohols exhibit at least 6, preferably at least 8 C atoms and the polyhydric alcohols preferably have 2 to 6 C atoms in the molecule, ;b) Esters of monocarboxylic acids of synthetic and/or natural origin with 6 to 16 C atoms, especially esters of corresponding aliphatically saturated monocarboxylic acids and 1- and/or polyfunctional alcohols of the under a) ;mentioned type, ;c) Esters of olefinic mono- and/or polyunsaturated monocarboxylic acids with at least 16, especially 16 to 24 C atoms and, in particular, monofunctional straight-chain and/or branched alcohols. ;Starting materials for the extraction of numerous monocarboxylic acids that fall into these subclasses, especially with higher carbon numbers, are vegetable and/or animal oils. Mention should be made of coconut oil, palm kernel oil and/or babassu oil, especially as application materials for the extraction of monocarboxylic acids of the predominant range up to C^g and of essentially saturated components. Vegetable ester oils, especially for olefinically mono- and optionally polyunsaturated carboxylic acids of the range of Ci6-24 are, for example, palm oil, peanut oil, castor oil, sunflower oil and especially rapeseed oil. However, synthetically extracted components are also important structural elements for the ecologically acceptable oil phases both on the carboxylic acid side and on the alcohol side. ;Invert drilling mud usually contains, together with the continuous oil phase, the finely dispersed aqueous phase in amounts from approx. 5 to 50 weight #. In water-based emulsion slurries, the dispersed oil phase is usually present in quantities from at least approx. 1 to 2 weight #, often in quantities of at least approx. 5 weight-it> at an upper limit for the oil proportion of approx. 40 to 50 wt-# - wt-#, always stated on the basis of the sum of the unloaded liquid fractions of oil/water. ;In addition to the water content, all common additives for comparable rinse aid types are taken into account. These additives can be water-soluble, oil-soluble and/or water- or oil-dispersible. ;Common additives are next to the emulsifiers defined in the invention, for example fluid loss additives, structure viscosity-building, soluble and/or insoluble substances, alkali reserves, agents for inhibiting the unwanted water exchange between drilled formations - for example water-swellable clays and/ or salt layer - and the flushing liquid, wetting agents for improved attraction of the emulsified oil phase on solid surfaces, for example to improve the lubrication effect, but also to improve the oleophilic closure of exposed rock formations, respectively rock surfaces, biocides, for example to inhibit the bacterial the attack on oil/water emulsions and the like. Individually, reference must be made here to the state of the art in question, described in detail for example in the technical literature mentioned at the outset, see especially Gray and Darley, et al., chapter 11, "Drilling Fluid Components". Only excerpts should therefore be quoted: Finely dispersed additives for increasing the flushing agent density: Barium sulphate (baryte) is very common, but calcium carbonate (calcite) or the mixed carbonate of calcium and magnesium (dolomite) are also used. ;Agents for building up the structural viscosity, which at the same time also act as fluid loss additives: In the first place, bentonite or hydrophobic bentonite must be mentioned here. For saltwater mud, other comparable clays, especially attapulgite and sepiolite, add considerable importance in practice. ;Also the co-use of organic polymer compounds of natural and/or synthetic origin can be of considerable importance in this context. Special mention must be made here of starches or chemically modified starches, cellulose derivatives such as carboxymethylcellulose, guar gum, xanthan gum or also purely synthetic water-soluble and/or water-mispersible polymer compounds, especially of the high-molecular-weight polyacrylamide compound type with or without anionic or cationic modification. ;Thinners for viscosity regulation: The so-called thinners can be of an organic or inorganic nature, examples of organic thinners are tannins and/or "Quebracho" extract. Further examples of this are lignite and lignite derivatives, especially lignosulfonates. As admittedly mentioned earlier, in a preferred embodiment of the invention, the co-use of toxic components is waived precisely at this point, whereby the corresponding salts with toxic heavy metals such as chromium and/or copper should be mentioned here in the first place. An example of inorganic diluents are polyphosphate compounds. Additives that inhibit the unwanted exchange of water with, for example, clays: In consideration here are the additives known from the state of the art regarding oil and water-based drilling fluids. In particular, this concerns halides and/or carbonates of alkali and/or alkaline earth metals, whereby corresponding potassium salts, possibly in combination with lime, may * have special significance.

Reference should be made, for example, to the corresponding publication in "Petroleum Engineer International", September 1987, 32-40 and "World Oil", November 1983, 93-97.

Alkali reserves: Inorganic and/or organic bases that are matched to the overall behavior of the flushing agent are taken into account here, especially corresponding basic salts or hydroxides of alkali and/or alkaline earth metals as well as organic bases. The type and amount of these basic components are thereby selected in a known manner and coordinated in relation to each other so that the treatment agent for boreholes is set to a pH value in the range from approximately neutral to weakly basic, especially to the range from approx. 7.5 to 11.

The quantity of the auxiliaries and additives used in any case is in principle within normal limits, and can therefore be found in the cited, relevant literature.

Examples

In the following examples 1 to 4, while maintaining a standard composition for oil-based drilling muds of the water/oil type, corresponding drilling muds are compiled, whereby the continuous oil phase is in any case formed by means of a selected oleophilic carboxylic acid ester with the following definition:

Ester mixture of essentially saturated fatty acids on the basis of palm kernel and 2-ethylhexanol, which in a decidedly predominant part goes back to C-^/^-fatty acids °g which corresponds to the following specification:

The ester mixture is available as a clear yellow liquid with a flash point above 165°C and a viscosity (Brookfield 20°C) of 7 to 9 cP.

On non-aged and on aged material, characteristic viscosity values are determined as follows: Measurement of the viscosity at 50°C in a Fann-35 viscometer from the company Baroid Drilling Fluids Inc. Plastic viscosity (PV) is determined in a manner known per se. yield strength (YP) and gel strength (lb/100 ft<2> and kg/m2 ) after 10 seconds and 10 minutes. In examples 1 and 2, the fluid loss value (ETHP) is further determined.

The aging of the drilling mud in question is carried out by treatment for a period of 16 hours at 125°C in an autoclave - in a so-called roller oven.

The drilling mud systems are assembled according to the following basic composition in a manner known per se:

Example 1

As an alkylglycoside-based emulsifier, the condensation product of glucose and a C-^-f one alcohol of natural origin is used (commercial product "Lorol C-^," from the applicant). The characteristic data determined on non-aged and aged material - as indicated above - are tabulated in the following summary.

Example 2

In the present example, the reaction product of glucose with a fatty alcohol mixture of natural origin and with a far predominant chain length of C±2-14 (the applicant's commercial product "Lorol 1214 S") is used as an alkylglycoside-based emulsifier. The values determined on unaged and aged material are as follows.

Example 3

The mixture from example 1 is repeated, in t-addition, however, as mentioned initially, a co-emulsifier based on C 10 -fatty acid is used here. The characteristic values determined on unaged and aged material are the following.

Example 4

The mixture from example 2 is repeated, however, work is also done here with the addition of the co-emulsifier on the basis of C₁g fatty acid.

The characteristic values determined on unaged and aged material are the following.

Example 5

In the following example 5, a water-based emulsion rinse agent is prepared using a complex oleophilic polycarboxylic acid ester with lubricant character as a dispersed oil phase according to the following work instructions: First, it is prepared using commercial bentonite (not hydrophobic) with tap water while setting a pH value of 9, 2 to 9.3 using caustic soda, a b% homogenized bentonite top slurry.

Starting from this pre-swollen aqueous bentonite phase, the individual components of the water-based ester oil emulsion are incorporated in successive procedural steps - in any case with intense thorough mixing - according to the composition below:

As oleophilic ester oil phase, the reaction product of trimethylolpropane (14 wt-5é), a commercial dimer fatty acid mixture (24 wt-#) and other oleic acid is used. The dimer fatty acid mixture contains 77 wt # of dimer acids and other tri- and higher polycarboxylic acids - here the weight-Sé is given on the basis of the dimer fatty acid mixture.

On the oil/water emulsion rinse aid produced in this way, the viscosity determinations are carried out as follows: First, the plastic viscosity (PV), yield strength (YP) and gel strength are determined on emulsion rinse agents at room temperature on non-aged material after 10 seconds and after 10 minutes.

The emulsion rinse agent is then aged for 16 hours at 90° C under static conditions, in order to examine the effect of temperature on the emulsion stability. The viscosity values are then determined again at room temperature.

Claims (16)

1. Use of surface-active alkylglycoside compounds of the water/oil type with the formula in which R means linear and/or branched, saturated and/or unsaturated alkyl with at least 8 C atoms, preferably with 10 to 22 C atoms, Z means one or more residues of aldoses and/or ketoses, especially hexose and/or pentose units as well as n means a number from 1 to 5 and especially from 1.2 to 2.5, as ecologically compatible emulsifiers in fluid and pumpable drilling mud or other fluid treatment agents for boreholes, which, together with a dispersed aqueous phase, exhibits a continuous and thus ecologically compatible oil phase and which is suitable for environmentally friendly utilization of biological deposits, especially of petroleum and natural gas deposits, whereby in the case of the use of oil phases exposed to hydrolysis corresponding oils are selected, which also in the case of a partial saponification in practical application does not lead to any toxicological, especially not any inhalation-toxicological danger. 2. Use according to claim 1 of alkylglycoside compounds which at least partially and preferably predominantly exhibit residues R in the general formula (I) with at least 12 C atoms, preferably with at least 16 C atoms, with simultaneous limitation of n to maximum values of 2. 3. Use according to claims 1 and 2 of the alkylglycoside compounds as the at least predominantly emulsifier part, but also together with other, especially biologically compatible water/oil emulsifiers. 4. Use according to claims 1 to 3 of the alkylglycoside compounds in amounts of 0.1 to 10 wt-#, preferably of 0.5 to 5 wt-#. and especially in amounts of 1 to 3 wt-#-wt-5é all stated on the basis of the sum of water and oil. 5. Use according to claims 1 to 4 of the alkylglycoside-based emulsifiers together with ester oils of monocarboxylic acids and/or polycarboxylic acids with 1- and/or polyfunctional alcohols, corresponding ester oils of carboxylic acid, oleophilic alcohols and/or corresponding ethers as ecologically compatible oil phases. 6. Use according to claims 1 to 5 of the alkyl glycoside compounds together with oil phases or oil mixture phases which exhibit flash points of at least 100°C, preferably above 135°C. 7. Use according to claims 1 to 6 of alkylglycoside-based emulsifiers in fluid and pumpable invert systems with a closed oil phase, which exhibit solidification values (pour and solidification points) below 0°C, preferably below -5°C and thereby in the temperature range from 0 to 5' C has a Brookfield (RVT ) viscosity not exceeding 55 mPas, preferably not exceeding 45 mPas, 8. Use according to claims 1 to 7 of the ecologically acceptable alkylglycoside emulsifiers of the water/oil type together with an oil phase which at least partially contains ester oils of monocarboxylic acids from at least one of the following subclasses: a) esters of Ci_5-monocarboxylic acids and 1- and/ or polyfunctional alcohols, whereby residues of 1-hydric alcohols exhibit at least 6, preferably at least 8 C atoms, and the polyhydric alcohols preferably have 2 to 6 C atoms in the molecule, b) esters of monocarboxylic acids of synthetic and/or natural origin with 6 to 16 C atoms, especially esters of corresponding aliphatically saturated monocarboxylic acids and 1- and/or polyfunctional alcohols of the type mentioned under a) c) esters of olefinic 1- and/or polyunsaturated monocarboxylic acids with at least 16, especially 16 to 24 C atoms, and especially monofunctional straight-chain and/or branched alcohols. 9. Application according to claims 1 to 8 of the alkylglycoside-based emulsifiers are used together with the excess alcohol used in their synthesis or at least a significant proportion thereof, whereby the proportion of free alcohol can amount to at least 50 mol-56, preferably at least 100 mol-5é - calculated on the basis of the alkyl glycoside compound. 10. Use according to claims 1 to 9 of the alkylglycoside compounds in essentially anhydrous form, for example as solution concentrates in ecologically acceptable solvents or as solids - here especially in granule form and thereby if desired in a mixture with particulate solids. 11. Invert drilling mud which is suitable for an environmentally friendly exploitation of geological deposits and which in a closed oil phase contains a dispersed aqueous phase together with emulsifiers and usual additional auxiliary substances, for example thickeners, fluid loss additives, ballast agents, water-soluble salts and alkali reserves, characterized in that together with an ecologically compatible, continuous oil phase, they contain surface-active alkylglycoside compounds of general formula (I) as emulsifier or emulsifier component. 12. Invert drilling mud according to claim 11, characterized in that they contain ester oils, oleophilic alcohols and/or corresponding ethers as an ecologically compatible, continuous oil phase. 13. Invert drilling mud according to claims 11 and 12, characterized in that they exhibit a plastic viscosity (PV) in the range from 10 to 60 mPas and a yield point (Yield Point YP) in the range from 5 to 40 lb/100 ft<2> (0.244 to 1.95 kg/m2 ) - all determined at 50°C. 14. Invert drilling mud according to claims 11 to 13, characterized in that, with the co-use of ester oils in the continuous oil phase, in particular corresponding esters of monocarboxylic acids, of polycarboxylic acids and/or carbonic acid, these ester oils make up at least one third, but preferably the predominant part of this ecological reconcile the oil phase. 15. Invert drilling mud according to claims 11 to 14, characterized in that the dispersed water portion amounts to 5 to 50 wt-#, preferably 10 to 30 wt-#, and in particular contains dissolved salts of the type CaCl2 and/or KC1. 16. Invert drilling mud according to claims 11 to 15, characterized in that the oil phase of the invert mud in the temperature range from 0 to 5°C exhibits a Brookfield (RVT) viscosity below 50 mPas, preferably not above 40 mPas.