EP0513041A1

EP0513041A1 - Use of selected ether-based emulsifiers in oil-based invert emulsions

Info

Publication number: EP0513041A1
Application number: EP19910902405
Authority: EP
Inventors: Heinz Müller; Claus-Peter Dr. Herold; Fritz Dr. Lange
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 1990-02-02
Filing date: 1991-01-24
Publication date: 1992-11-19
Also published as: NO922717D0; DE4003028A1; JPH05503955A; NO922717L; CA2075208A1; WO1991011254A1

Abstract

L'invention décrit de nouveaux émulsifiants sans N s'utilisant dans des émulsions inverties à base huileuse. Les émulsifiants objets de l'invention sont des éthers partiels d'alcools polyfonctionnels inférieurs comprenant des alcools monofonctionnels contenant au moins 8 atomes C et/ou leurs alkoxylats. Les éthers partiaux de glycérine correspondants sont particulièrement appropriés. On peut fabriquer avec les émulsifiants des fluides de forage invertis du type indiqué ci-dessus et améliorés sur le plan écologique, appropriés pour une exploitation de gisements géologiques qui ne nuise pas à l'environnement, et contenant une phase aqueuse dispersée à l'intérieur d'une phase huileuse fermée, avec d'autres adjuvants traditionnels, par exemple, des émulsifiants, des agents alourdissants, épaississants, des additifs fluid-loss et des réserves alcalines.The invention describes new N-free emulsifiers for use in invert oily-based emulsions. The emulsifiers which are the subject of the invention are partial ethers of lower polyfunctional alcohols comprising monofunctional alcohols containing at least 8 C atoms and / or their alkoxylates. The corresponding partial glycerin ethers are particularly suitable. Inverted drilling fluids of the type indicated above and ecologically improved can be produced with emulsifiers, suitable for the exploitation of geological deposits which do not harm the environment, and containing an aqueous phase dispersed inside. a closed oily phase, with other traditional adjuvants, for example, emulsifiers, weighting agents, thickeners, fluid-loss additives and alkaline reserves.

Description

"Use of selected ether-based emulsifiers for oil-based invert emulsions"

The invention relates to the use of selected emulsifiers with increased ecological compatibility for the production of W / 0 invert emulsions and the technical use of such stabilized emulsion types in the context of drilling fluids and invert drilling fluids based thereon, which are characterized by high ecological compatibility and at the same time airszetrimeπ raft good standing and usage. An important area of application for the new drilling mud systems is offshore drilling for the development of, for example, oil and / or natural gas deposits. The use of the systems stabilized with the emulsifiers according to the invention is of particular importance in the marine field, but is not restricted to this. Drilling in permafrost areas should be mentioned as an important area of use

Subject to control. However, the new flushing systems according to the invention can also be used quite generally in land-based drilling, for example in geothermal drilling, in petroleum / natural gas, in carrying out geoscientific drilling and in drilling in the mining sector.

The state of the art

Oil-based drilling fluids are generally used as so-called invert emulsion muds, which consist of a three-phase system: oil, water and finely divided solids. These are preparations of the W / O emulsions type, ie the aqueous phase is heterogeneously finely dispersed in the closed oil phase. There is a plurality for stabilizing the overall system and for setting the desired usage properties of additives, in particular emulsifiers or emulsifier systems, weighting agents, thickeners, fluid loss additives, alkali reserves, viscosity regulators and the like. For details, reference is made, for example, to the publication PA Boyd et al. "New Base Oil Used in Low-Toxicity Oil Muds" Journal of Petroleum Technology, 1985, 137 to 142 and RB Bennett "New Drilling Fluid Technology - Mineral Oil Mud" Journal of Petroleum Technology, 1984, 975 to 981 and the literature cited therein .

The stability and usability of such invert emulsions under the conditions of practical use are largely determined by the W / O emulsifiers used or the corresponding emulsifier systems. Various requirements are placed on these emulsifiers. They must guarantee the stability of the emulsion not only at ambient temperature but also under the often high temperatures on the bottom of the borehole. In many cases, barite or other inorganic weighting materials of higher density are added to the drilling fluid. The emulsifier should also improve the oil wettability of these inorganic weighting materials. Finally, it is known that the sealing of the filter cake deposited on the borehole wall against the passage of oil, water and / or W / O emulsion is largely determined by the emulsifiers used in each case.

In current practice, depending on the oil used, ie diesel or mineral oil with a low aromatic content, different emulsifier systems are used. Alkylbenzenesulfonates, fatty acids or fatty acid salts and aminoamides and idazolines are used particularly frequently. Such emulsifier systems are e.g. B. described in US Patent 4,374,737 and the literature cited therein. Nitrogen-containing ones are of particular importance in practical use Emulsifier systems based on aminoamides and / or imidazolines. Although these emulsifiers are highly effective with regard to the technical requirements described, they are increasingly regarded as not harmless for ecological reasons. The compounds in particular show because of their content relatively high toxicities to aquatic organisms against aquatic organisms and are therefore, taking into account the increasing demands on ecological compatibility today, for example for sea-based drilling or for drilling in

Permafrost area less desirable.

The object of the invention and its technical solution

The object of the present invention is to provide emulsifiers or emulsifier systems which are nitrogen-free and at the same time are ecologically compatible to a high degree. In particular, there should be a high level of compatibility with the sensitive marine systems. At the same time, the technical requirements given by practice should be able to be met at least to the extent known to date by using the new emulsifiers.

In a further task, the invention aims to create systems of the type described, which contribute to the further optimization of these tools, through the simultaneous use of the new environmentally compatible emulsifiers and, at the same time, of oil phases with increased environmental compatibility. In this last-described embodiment, the teaching of the invention makes use of older proposals by the applicant regarding the nature of the closed oil phase in invert drilling fluids, which will be discussed in more detail below. Accordingly, the invention relates in a first embodiment to the use of partial ethers of lower polyfunctional alcohols with monofunctional alcohols containing at least 8 carbon atoms and / or their alkoxylates as nitrogen-free emulsifiers in oil-based invert emulsions.

The invention is based on the knowledge that selected, in particular oil-soluble partial ethers of the type described for the work area concerned here, with their varied requirements for the function of the emulsifier or the emulsifier system, surprisingly well for the exchange and replacement of the most effective emulsifiers to date Are based on nitrogen-containing compounds.

In a further embodiment, the invention relates to invert drilling fluids which, in a closed oil phase, contain a disperse aqueous phase together with customary other auxiliaries, for example emulsifiers, weighting agents, thickeners, fluid loss additives and alkali reserves, and are characterized thereby that they contain, as nitrogen-free W / O emulsifiers, at least some of the compounds of the type described above based on selected partial ethers of lower polyfunctional alcohols. According to the invention, it is preferred that such nitrogen-free partial ethers form the at least predominant proportion of the emulsifiers used in the invert rinse and, if additional emulsifier components are also used, nitrogen-free systems are preferably also used. In addition, known nitrogen-containing emulsifiers can also be used together with the selected nitrogen-free partial ethers. However, the selected partial ethers should also form the at least predominant portion of the emulsifiers used in the invert rinse. In preferred embodiments, the emulsifiers are used in invert drilling fluids, the closed oil phase of which is formed at least in part and preferably at least predominantly from oils which are more environmentally compatible. Preferred oil phases here are ester oils, oil-soluble alcohols and / or oil-soluble ethers of the nature specified below.

The new nitrogen-free emulsifiers are, in particular, partial ethers of polyhydric alcohols having 2 to 6 carbon atoms and 2 to 6, preferably 2 to 4, hydroxyl groups. Corresponding partial ethers of ethylene glycol, the

1,2-propanediol, 1,3-propanediol, trimethylolpropane, glycerol and / or pentaerythritol. Such emulsifier systems which contain at least partially glycerol partial ethers of the type specified can be of particular importance in the context of the invention.

The monofunctional alcohols used to etherify a portion of the hydroxyl groups of the lower polyfunctional alcohols are oil-soluble compounds of this type or are derived from corresponding oil-soluble monofunctional alcohols having at least 8 carbon atoms. Suitable for partial etherification are in particular straight-chain and / or branched monofunctional alcohols with 8 to 36 C atoms and preferably those with 8 to 24 C atoms in the molecule. Corresponding monofunctional alcohols with 10 to 18 carbon atoms can be of particular importance. The alcohols themselves can be aliphatically saturated and / or mono- and / or poly-olefinically unsaturated. Corresponding alcohols of natural origin can be of particular importance in the context of the invention. Particularly important examples of this class of substances are the so-called fatty alcohols, which are accessible on a large industrial scale, and which are reductive from fatty acids of natural origin or their derivatives. Partial ethers of this nature are characterized by their high ecological compatibility even with the particularly sensitive marine systems. However, the invention is not restricted to such components of natural origin. As is well known, synthetic chemistry is also able to provide comparable ecologically compatible components.

In addition to or instead of the monofunctional alcohols of the ¹ type described, the partial etherification of the polyfunctional lower alcohols can also be carried out using alcohol alkoxylates, such as are obtained in particular by ethoxylation and / or propoxylation of the monofunctional alcohols. The ethoxylated derivatives in particular can be of particular importance here as etherification components. If such alkoxylated fatty alcohols are used for ether formation, particular preference is given to corresponding alkoxylates with an average of up to 12 alkoxy radicals and in particular corresponding alcohol derivatives with an average of up to 8 alkoxy radicals in the alkoxylated monofunctional alcohol.

Partial ethers based on glycerol can be of particular importance both for reasons of ecological compatibility and for reasons of the required technical qualification. Here, in particular, monoethers of glycerol have proven to be effective emulsifiers and stabilizers of the invert system, but glycerol diethers can also be used at least in part in the systems. According to the invention, these partial ethers of glycerol can also be present in a mixture with excess free glycerol. This means that there is no need to separate off an excess of glycerol caused by the preparation of the ethers. Particularly suitable emulsifiers are ethers of the type described which have flash points above 100 ° C. and in particular above 120 ° C. Compounds of this type can be safely used in drilling fluid based on invert emulsions. They are usually present in the multicomponent mixture in amounts below 10% by weight, preferably in amounts in the range from about 1 to 5% by weight, based in each case on invert rinsing.

Particularly suitable for the purposes of the invention are oleophilic and at most water-soluble ethers of the following general formula (I)

JR - 0 (Alk-O) J-χ R '- (0H) _y _ _x (I)

In this formula means

R is a straight-chain and / or branched hydrocarbon residue with 8 to 36 C atoms and preferably a corresponding residue with 10 to 24 C atoms. If there are several etherifying residues of the type concerned here on the polyfunctional alcohol base molecule, the same, but also mixtures of different residues R of the given definition may be present. In the case of ethers based on monofunctional alcohols of natural origin, there are generally mixtures of homologous alcohol residues, the composition of which is derived in terms of the number of the respective carbon atoms and quantitative distribution of the alcohol residues of different chain lengths by the processes for isolating the alcohol mixtures based on natural products.

The radical Alk-0 from the general formula (I) denotes a lower alkylene oxide radical, ethylene oxide and / or propylene oxide radicals being preferred in particular. The ethylene oxide residue is of particular importance here. In the general formula (I), n denotes a number from 0 to 12 and preferably has a value from Q to 8.

y from the general formula (I) gives the number of hydroxyl groups of the lower polyfunctional alcohol R '- (0H) y used. In the sense of the definition according to the invention, y preferably denotes a number from 2 to 6 and in particular a number from 2 to 4, where, in the case of glycerol, y assumes the value 3.

x from the general formula (I) is an integer or fractional number and preferably has the value of at least 1. Here, x is necessarily a number that is less than y. This results from the requirement according to the invention for the use of the partial ethers of the lower polyfunctional alcohols submitted. In preferred partial ethers, x can have the value 1 and / or 2. However, the balance between free and etherified hydroxyl groups of the lower polyfunctional alcohol is to be coordinated in a manner known per se in such a way that the compounds of the general formula (I) used are in fact W / 0 emulsifiers of the required type and thus in particular oil-soluble compounds are.

Finally, R 'from the general formula (I) means the radical of the lower polyfunctional alcohol used which is free of hydroxyl groups and has in particular 2 to 6, preferably 2 to 4, carbon atoms.

The ethers used according to the invention as emulsifiers can be prepared in a manner known per se under conventional etherification conditions. Two types are particularly suitable driving types. Thus, in a first embodiment, alcohols of the general formula (Ib) R-0- (Alk-0) _n -H, in which R, Alk-0 and n have the meanings * indicated, can be sulfated in a manner known per se. The sulfates formed are then reacted with the multifunctional lower alcohols in a known manner to give the partial ethers of the general formula (I).

Instead of the alcohols of the general formula (Ib), the corresponding halide compounds, in particular the corresponding chlorides, can be reacted with the lower polyfunctional alcohols in a manner known per se to give the ethers of the general formula (I).

For the preparation of the partial ethers of lower polyfunctional alcohols, this reaction component latter is used in a preferred embodiment in a molar excess, with even more fold molar excess can be useful for example if, for example, ^'monoether or predominantly monoether reaction mixtures containing required. For the purposes of the invention, the resulting reaction mixtures, which in addition to the partial ethers formed also contain free polyfunctional lower alcohols, can be used as such in the oil-based invert emulsions. If desired, however, the unreacted portion of the polyfunctional alcohol can also be withdrawn from the reaction mixture at least in part in a manner known per se. Of particular importance for the first-mentioned process variant of etherification via the alcohol sulfates is furthermore that the sulfate salts formed during the etherification, in particular the corresponding sodium sulfate, may also remain in the reaction product, so that particularly inexpensive access to those used according to the invention can be obtained here There are emulsifiers in industrial use. As indicated above, the emulsifiers used according to the invention based on the partial ethers can be used in oil-based invert rinses of any desired oil phase. Accordingly, the diesel oil fractions still used on a large scale as well as the corresponding fractions of low-aromatic hydrocarbon compounds are suitable as a closed oil phase.

To achieve the object according to the invention of using work equipment of improved ecology and in particular drilling biologically acceptable drilling fluids, the invention provides for the use of selected oil phases as described in a number of older applications by the applicant. Accordingly, a first class of particularly important oil components are ester oils in the sense of the inventive action, as described in particular in the earlier applications P 3842659.5, P 3842703.6, P 3907391.2 and P 3907392.0 (D 8523, D 8524, D 8606 and D 8607) . The disclosure content of these named applications is hereby expressly made the subject of the present disclosure of the invention.

Together with ester oils of this type or instead of these ester oils, however, selected oil-soluble alcohols or selected oil-soluble ethers are also suitable as the base oil of the invert rinse, as used, for example, in the earlier patent applications P 39 11 238.1 and P 39 11 299.3 (D 8511 and D 8539 ) are described by the applicant. The subject of these publications is hereby expressly made the subject of the present disclosure of the invention.

The same applies to invert drilling fluids of the type concerned according to the invention - regardless of the particular nature of the closed oil phase - that they are in preferred embodiments have a plastic viscosity (PV) in the range of about 10 to 60 Pas and a yield point (YP) in the range of about 24 to 190 dPa - each determined at 50 ° C. It can furthermore be preferred that when ecologically compatible oils are used in the closed oil phase, the ester oils - preferably ester oils from monocarboxylic acids and 1- and / or 2-functional alcohols - at least about a third, preferably the predominant ones Make up the proportion of these ecologically compatible oils.

The oil phase of the invert sludge should expediently have a Brookfield (RVT) viscosity below 50 mPas and preferably not above 40 mPas in the temperature range from 0 to 5 ° C.

The disperse water content of the invert rinses is expediently 5 to 45% by weight, preferably approximately 10 to 25% by weight. Salts, for example of the type of CaCl2 and / or KC1, can be dissolved in the aqueous phase.

Other mixing components of the invert drilling fluid

All usual mixture components for conditioning and for the practical use of the invert drilling mud sludge are considered here, as they are used according to current practice with mineral oils as a closed phase. In addition to the disperse aqueous phase, the oil phase and the emulsifiers are all

There are weighting agents, fluid loss additives, viscosity formers and alkali reserves.

In practice, hydrophobicized lignite is used in particular as a fluid loss additive and thus in particular to form a dense covering of the drilling walls with a largely liquid-impermeable film. Suitable amounts are for example in the range from about 15 to 20 lb / bbl or in the range from about 5 to 7% by weight, based on the oil phase.

In drilling fluids of the type concerned here, the viscosity former usually used is a cationically modified, finely divided bentonite, which is present in particular in amounts of about 8 to 10 lb / bbl or in the range of about 2 to 4% by weight, based on the oil phase. can be used. The weighting agent normally used in the relevant practice for setting the required pressure compensation is barite, the additional amounts of which are adapted to the respectively expected conditions of the bore. For example, by adding barite it is possible to increase the specific weight of the drilling fluid to values in the range up to about 2.5 and preferably in the range from about 1.3 to 1.6.

Details of the usual composition of invert drilling fluids, the measurement methods used to test them and the determination of the parameters determined in the process are the subject of numerous publications of the state of the art in print as cited at the beginning. Detailed information can be found, for example, in the "Manual Of Drilling Fluids Technology" manual from NL-Baroid, London, GB, there in particular under the chapters "Mud Testing - Tools and Techniques" and "Oil Mud Technology", which are of interest to the specialist community is freely accessible.

In particular, a characteristic parameter for the respective invert rinsing in the so-called HT / HP test under standard conditions (125 ° C.) is also described here. The filtrate quantities determined here under standard conditions, which occur at high pressures and temperatures, are meaningful values, especially for the suitability of the emulsifiers used in each case. Accordingly, emulsifiers are preferred according to the in the respective drilling fluid under standard conditions (HT / HP; 125 ° C) result in a fluid loss value in the range up to a maximum of 20 ml and preferably up to a maximum of 12 ml. Particularly suitable values are in the range below 10 ml, for example in the range from 1 to 8 ml.

The examples given below describe the production of a plurality of partial ethers in the sense of the definition according to the invention and their use as a stabilizer for drilling fluids. The two different drilling fluid types I and II given below are used.

Drilling fluid I (low aromatic oil)

170 ml carrier oil (BP 83 HF)

4 g organophilic bentonite (Geltone, NL Baroid)

4.5 g organophilic lignite (Duratone, NL Baroid)

62 ml water

30 g CaCl2 x 2 H2O

6 g emulsifier (see table 1)

3 g stearic acid

3 g Ca (0H) ₂ 180 g barite

The following tests * were carried out to test the properties of these and other oil rinses:

* (Standard Procedure, RP 13 B (8th Ed) Standard Procedure for Testing Drilling Fluids)

The viscosity was measured at 50 ° C. in a Fann 35 viscometer from NL Baroid. Here were the plastic ones Viscosity, the yield point and the gel strength determined after 10 seconds and 10 minutes.

The oil rinse samples were then heated (aged) for 16 hours at 125 ° C. in small autoclaves, in a so-called "roller oven", in order to check the influence of temperature on stability. The viscosity was then determined again at 50 ° C.

In addition, the fluid loss at 125 ° C. was determined using an HT / HP filter cell (Baroid HT / HP cell No. 387).

Drilling fluid II

(Flushing based on fatty acid esters with an oil / water ratio of 90:10)

239 ml fatty acid ester (isobutyl oleate)

6 g organophilic bentonite (Omnigel, Milpark)

9 g emulsifier (see table 2)

20 g organophilic lignite (Duratone, NL Baroid)

28 g H ₂ 0

12 g CaCl2 x 2 H ₂ 0

4 g Ca (0H) ₂

259 g barite

15 B e i s p i e l e

example 1

Emulsifier A

1105 g (12 moles) of glycerol and 1000 ml of hexanol were placed in a flask, flushed three times with nitrogen and 2772 g of 26.8% strength aqueous C12 / 14-8 E0 fatty alcohol (FA) sulfate (1 mole) in 6 hours. - (Composition of the FA mixture: 70 to 75% by weight of saturated C12-FA; 24 to 30% by weight of saturated C14-FA; balance of saturated CIQ- and C15-FA) - at a temperature of 90 ° C sucked into the reaction mixture in a water jet vacuum of 15 mbar and dewatered in the process. Then 44 g (1.1 mol) of NaOH were added at 150 ° C. and the hexanol was removed by distillation in a water jet vacuum. The mixture was heated to 170 ° C., stirred at this temperature for 8 hours, cooled to 90 ° C., washed twice with water and then dried. 780 g of the corresponding glycerol ether (OHZ 318) were obtained.

Example 2

Emulsifier B

45 kg (488.7 mol) of glycerol and 7.2 kg (90 mol) of 50% aqueous sodium hydroxide solution were placed in a reaction vessel under a nitrogen atmosphere and dehydrated at 150.degree. 26.1 kg (90 mol) of a sodium FA sulfate (79 to 75% C12-FA, 24 to 30% C14-FA, remainder saturated CIQ- and C16-FA) were added to the well-dewatered mixture in two Portions and the reaction mixture warmed to 175 ° C. After 8 hours the mixture was cooled to 90 ° C and washed twice with 20 kg of water each. After drying in vacuo, 18 kg (83%) of the glycerol ether were obtained.

Analyte. Data: OHZ 366.3

Example 3

Emulsifier C

91.2 kg of 99.5% glycerol (848 mol) and 3.11 kg of NaOH pellets are placed in a stirred tank under nitrogen. The mixture was heated to 150 ° C. for 3 hours, water distilling off. 33.9 kg (70.7 mol) of sodium C12 / 14-2 EO-FA sulfate - FA mixture were then added in portions to the glycerolate at a temperature of 120 ° C. as in Example 1-79.5% strength spray new. given, again distilling off water. In order to remove the remaining traces of water, a lamp vacuum was applied at 130 ° C. The flask was vented with nitrogen and heated to 170 ° C. The mixture was stirred at 170 ° C. for 6 hours. The mixture is then cooled to 100 ° C. and washed twice with 2500 g of water each time and filtered, giving 950 g of the end product, the OHN of which was 407.6.

Example 4

Emulsifier D

553 g (6 mol) of glycerol and 40 g of NaOH (1 mol) were placed in a 3-necked flask and stirred at 150 ° C. for 3 hours. Then 344.5 g (1 mol) of sodium Ci2 / i8-FA sulfate - composition of the FA mixture: 0 to 3% by weight of CIQ; 48 to 58 wt% C12; 19 to 24 wt% C14; 9 to 12% by weight Ci6, * 11 to 14% by weight cis - added and stirred at 175 ° C. for 30 minutes. Another 40 g (1 mol) NaOH and 344.5 g (1 mol) of sodium Ci2 / i8- ^A1 alkyl sulfate were stirred at 175 ° C. After cooling, it was washed twice with water and dried. 542 g of the were obtained OHZ: 290.

Example 5

Emulsifier E

2336 g (25.2 mol) of glycerol 99.5% and 336 g (4.2 mol) of 50% sodium hydroxide solution are placed in the vessel under a nitrogen atmosphere. The mixture is heated to 175 ° C. for 2 hours, water distilling off. 1440 g (4.2 mol) of sodium cetylstearyl sulfate (sodium Ci5 / i8-FA sulfate (FA mixture: 0 to 3% by weight of C14; 45 to.) Were then added to the glycerol enolate in two portions at a temperature of 175 ° C. 55% by weight of CIÖ 45 to 55% by weight of Ciss), the mixture is stirred for 8 hours and then cooled to 100 ° C. and washed twice with 3000 g of water and dried, giving 1019 g of the glycerol ether OHZ of the final product was 282.

Example 6

Emulsifier F

In a 3-neck flask, 138 g (1.5 mol) of glycerol and 80 g of 50% (1 mol) sodium hydroxide solution were heated at 150 ° C. for 3 hours under an N2 atmosphere and water was distilled off. Then 296.1 g (1 mol) of sodium Ci2 / i4-FA sulfate - FA mixture of Example 1 - were added in three portions at 180 ° C. and stirred at 180 ° C. for 8 hours. After cooling, it was washed twice with water and dried in vacuo. 163 g of a solid substance with an OH value of 299.5 were obtained. Example 7 Emulsifier G

In a 3-neck flask, 1380 g of 99.5% glycerol (15 mol) and 400 g of 50% sodium hydroxide solution (5 mol) were added under an N2 atmosphere. The mixture was heated to 150 ° C. for 3 hours while separating off water by distillation, then in a vacuum of 25 to 40 mbar for 1 hour. Then 883.5 g (5 mol) of decyl chloride were added and the mixture was heated at 170 ° C. for 8 hours. After cooling, it was washed twice with 1.5 kg of water and dried. The yield was 905 g of a light yellow, slightly viscous liquid. The product was distilled and the OHZ of the distillate was 482.

The emulsifiers were then used and tested in the drilling fluids I and II in the manner indicated above. The results obtained are summarized in Tables 1 below (drilling fluid I) and 2 (drilling fluid II).

For comparison, a nitrogen-containing emulsifier of current practice was produced as follows:

Emulsifier for comparison

831 g of tall oleic acid are heated to 100 ° C. under N. Then 171 g of diethylene tria in are carefully added and the mixture is then heated to 210.degree.

52 g of water are separated off. It is cooled to 80 ° C. and 61.3 g of maleic anhydride are added in portions. The temperature should not rise above 90 ° C. After the maleic anhydride has reacted, the mixture is heated to 210 ° C. for 1 hour and about 11 g of water are distilled off. Using this comparative emulsifier, a recipe according to "Bohrspülung I" is compiled and tested. The values obtained are included in Table 1.

Table 1 (drilling fluid I)

Emul-Plast. Visc. Yield strength gel strength HT / HP gator (mPas) (dPa) 10 see 10min fluid loss (dPa) at .125 ° C

Emul-Plast. Visc. Yield strength gel strength HT / HP gator (mPas) (dPa) 10 see 10min fluid loss (dPa) at 125 ° C

Claims

Patent claims

1. Use of partial ethers of lower polyfunctional alcohols with monofunctional alcohols containing at least 8 carbon atoms and / or their alkoxylates as nitrogen-free emulsifiers in oil-based invert emulsions.

2. Embodiment according to claim 1, characterized in that partial ethers of polyhydric alcohols having 2 to 6 carbon atoms and 2 to 6, preferably having 2 to 4, hydroxyl groups, in particular partial ethers of ethylene glycol, propanediols, trimethylolpropane, pentaerythritol and / or the glycerol can be used.

3. Embodiment according to claims 1 and 2, characterized gekenn¬ characterized in that partial ethers of the lower polyfunctional alcohols with straight-chain and / or branched monofunctional alcohols with up to 36 carbon atoms, preferably with 8 to 24 carbon atoms and in particular with 10th up to 18 carbon atoms and / or their alkoxylates with preferably up to 12 alkoxy radicals, in particular with up to 8 alkoxy radicals.

4. Embodiment according to claims 1 to 3, characterized gekenn¬ characterized in that partial ethers with saturated and / or olefinically unsaturated monofunctional alcohol residues of natural origin, in particular residues of fatty alcohols and / or their ethoxylates are used.

5. Embodiment according to claims 1 to 4, characterized gekenn¬ characterized in that mono- and optionally diether are used on glycerin, which are also mixed with over-

^' free glycerin can be present.

6. Embodiment according to claims 1 to 5, characterized gekenn¬ characterized in that ether with flash points above 100 ° C, preferably above 120 ° C, are used in drilling fluids based on invert emulsions, which contain a disperse aqueous phase in a closed oil phase, if necessary together with conventional auxiliaries, and are suitable for the environmentally friendly development of biological deposits.

7. Embodiment according to claims 1 to 6, characterized gekenn¬ characterized in that the nitrogen-free ethers form the at least predominant proportion of the emulsifiers used in the invert rinse and preferably nitrogen-free systems are used when additional emulsifier components are used.

8. Embodiment according to claims 1 to 7, characterized gekenn¬ characterized in that the ether emulsifiers are used in sea-based bores and / or in bores in low temperature ranges, in particular in permafrost areas.

9. Embodiment according to claims 1 to 8, characterized gekenn¬ characterized in that the ether emulsifiers in amounts below about 10 wt .-%, preferably in amounts in the range of about 1 to 5 wt .-% - each based on invert rinsing - Be used.

10. Embodiment according to claims 1 to 9, characterized gekenn¬ characterized in that the ether emulsifiers are used in invert systems based on environmentally friendly oil phases, in particular based on anaerobically degradable oil phases such as ester oils, oleophilic alcohols and / or oleophilic ethers.

11. Embodiment according to claims 1 to 10, characterized gekenn¬ characterized in that ether emulsifiers are used which in the drilling fluid under the standard conditions (HT / HP; 125 ° C) a fluid loss value in the range up to a maximum of 20 ml, preferably up to a maximum of 12 ml.

12. Embodiment according to claims 1 to 11, characterized gekenn¬ characterized in that oleophilic and at most limited water-soluble ethers of the general formula (I)

JR - 0 (Alk-0) _n ^~ R '- (0H) _y . _x (I)

be used in the

R represents a straight-chain and / or branched hydrocarbon radical with 8 to 36 C atoms, preferably with 10 to 24 C atoms,

Alk-0 is a lower alkylene oxide radical, in particular the ethylene oxide and / or prσpyleπσxidrest, n is a number from 0 to 12, preferably from 0 to 8, x is an integer or fractional number greater than 1 but less than y and y is a number from 2 to 6 , preferably from 2 to 4 and R ^{1 is} the hydroxyl-free radical is a lower, in particular water-miscible polyhydric alcohol having in particular 2 to 6 carbon atoms and preferably 2 to 4 carbon atoms.

13. Invert drilling fluids which are suitable for an environmentally friendly development of geological deposits and which contain a disperse aqueous phase together with customary additional auxiliaries, for example emulsifiers, weighting agents, thickeners, fluid loss additives and alkali reserves, in a closed oil phase , characterized in that they contain, as W / 0 emulsifiers, at least partially oil-soluble partial ethers of lower polyfunctional alcohols with monofunctional alcohols and / or their alkoxylates containing at least 8 carbon atoms.

14. Invert drilling fluid according to claim 13, characterized in that it contains ester oils, oleophilic alcohols and / or corresponding ethers as the ecologically compatible closed oil phase.

15. Invert drilling fluid according to claims 13 and 14, characterized ge indicates that it has a plastic viscosity (PV) in the range of about 10 to 60 mPas and a yield point (yield point YP) in the range of about 24 to 190 dPa - each determined at 50 ° C.

16. Invert drilling fluid according to claims 13 to 15, characterized ge indicates that when using ecologically compatible oils in the closed oil phase, ester oils make up at least about one third, preferably the major part, of these ecologically compatible oils.

17. Invert drilling fluid according to claims 13 to 16, characterized ge indicates that its disperse water content is about 5 to 45 wt .-%, preferably about 10 to 25 wt .-% and in particular salts of the type CaCl2 and / or KC1 contains dissolved.

18. Invert drilling fluid according to claims 13 to 17, characterized ge indicates that the oil phase of the invert sludge in the temperature range from 0 to 5 ° C has a Brookfield (RVT) viscosity below 50 mPas, preferably not more than 40 mPas.