WO2007048518A1

WO2007048518A1 - Thickeners for oil-based drilling muds

Info

Publication number: WO2007048518A1
Application number: PCT/EP2006/009948
Authority: WO
Inventors: Heinz Müller; Diana MÄKER; Markus Scherer
Original assignee: Cognis Oleochemicals Gmbh
Priority date: 2005-10-24
Filing date: 2006-10-16
Publication date: 2007-05-03
Also published as: DE102005051165A1

Abstract

Polymers which are selected from the group of olefin polymers, hydrogenated polyisoprenes, hydrogenated copolymers of butadiene and isoprene, and/or hydrogenated copolymers of butadiene, isoprene and styrene, optionally in a blend with a nonaqueous solvent, a dispersant and emulsifiers, are suitable as thickeners in drilling muds which contain at least 70% by weight of a nonaqueous oil, of a weighting agent and of a water-soluble salt, and also optionally emulsifiers, fluid loss additives, alkali reserves, wetting agents, biocides, diluents and/or corrosion inhibitors.

Description

Thickener for oil-based drilling fluids

The present invention relates to additives for oil-based drilling fluids, such as those used to drill onshore or offshore geothermal wells to drill gas or oil wells, and especially for thickening such mud systems.

Borehole treatment products are all types of auxiliary fluids that can be used in the drilling of oil or natural gas deposits. The so-called Bohrspülflüssigkeiten and built Bohrspülschlämmen or drilling fluids, which can be used both in land-based as well as in seaborne boreholes are of particular importance. On the one hand known water-based drilling fluids containing about 1 to 50% emulsified oil phase - in addition to the other conventional auxiliaries such a drilling fluid - which are also referred to as O / W emulsion rinses. On the other hand, oil-based scavenging systems are in widespread use in practice in which the oil forms the flowable phase or at least a substantial portion of the flowable phase as a closed oil phase. Of particular importance here are the so-called invert drilling muds, which contain a disperse aqueous phase in the closed oil phase on the basis of W / O emulsions. The content of the dispersed aqueous phase is usually in the range of at least about 5 to 10% by weight to about 50 to 60% by weight. In addition to these W / O-invert drilling muds, however, the so-called true-oil muds are known whose liquid phase is formed almost exclusively from a closed oil phase, the most small amounts - usually not more than about 5 to 10 wt .-%. - Contain dispersed in aqueous phase.

The non-aqueous phase of such purge systems is formed by the so-called carrier fluid. It is originally about diesel oil, which added offset with certain additives, the actual Bohrspülung. However, at the end of the eighties, there was a demand for environmentally friendly flushing systems and thus carrier fluids. These should in particular be better biodegradable than the diesel oil used so far.

In addition to various liquid esters, as described, for example, in EP 0 374 672 A1, olefinic hydrocarbons were also tested for their usefulness. encryption Mention should be made here by way of example to EP O 765 368 A1 of the Applicant, which relates to the use of so-called alpha-olefins as carrier fluid.

Drilling muds for soil digestion are in practice dispersions of a liquid and a solid phase, wherein the drilling muds a significant amount of solids is present. These are liquid rinsing systems for sinking rock boreholes while applying the detached cuttings. Therefore, it is necessary that the drilling fluids have a certain density (usually greater than 1.2 g / cm, preferably greater than 1.5 g / cm ³ ) in order to prevent a possible break-in of the formation can. For this purpose, the rinse solids are added to the weighting. As a rule, barium sulfate is used. Such liquids usually exhibit a thixotropic behavior under shear stress, ie the viscosity of these systems, which are also referred to as non-Newtonian fluids, decreases under the influence of increasing shear stress or shear rate. In practice, this behavior can lead to problems if the liquids are to be transported or pumped and thereby exposed to different mechanical loads. In addition, additives are used as thickeners, which increase the viscosity of the mud to facilitate the removal of the cuttings.

From the prior art, a variety of additives are known to increase the viscosity of oil-based fluids, such as engine oils or lubricants. As a rule, polymer-based thickeners are used for this purpose.

However, when using such additives in the field of drilling muds increased demands are placed on these thickeners. In the practical use of a drilling mud, their rheological properties change continuously, for example due to the nature and quantity of the cuttings or due to liquid or gas intrusions from the rock formation surrounding the borehole. The additives must also be liquid in a wide temperature range, in particular those additives are sought, which are still operational even at low temperatures of well below 0 ⁰ C. Furthermore, the additives should withstand very high pressures or shear loads and meet the biodegradability requirements that are increasingly being imposed on such systems. In addition, the use of these additives must not affect the stability of the drilling fluid system. For example, EP 0 705 854 A1 describes terpolymers of methacrylic acid, ethyl acetate and an ethylenically unsaturated monomer which are suitable for thickening purely aqueous systems, drilling muds also being mentioned. However, the document contains no concrete example of such use. US 2004/0162405 discloses cationic polyelectrolytes as an additive in drilling fluids, although this document also lacks specific embodiments for this use. No. 5,708,107 describes water-soluble nitrogen-containing polymers which can be used as thickeners for drilling fluids. However, oil-based systems are more widespread than the purely aqueous drilling fluids, which includes the above invert systems as well as pure oil-based muds (so-called true oil muds).

The object of the present invention was to provide suitable thickeners for oil-based drilling fluids available. It has been found that the use of certain polymers is suitable for achieving the stated object.

A first subject of the present invention therefore relates to the use of polymers selected from the group of olefin polymers of ethylene and propylene, hydrogenated polyisoprenes, hydrogenated copolymers of butadiene and isoprene, and / or hydrogenated copolymers of butadiene, isoprene and styrene, optionally in admixture with a non-aqueous solvent, a dispersant and emulsifiers, as thickeners in drilling muds containing at least 70 wt .-% of a non-aqueous oil, a weighting agent and a water-soluble salt and optionally emulsifiers, fluid loss additives, alkali reserves, wetting agents, biocides, thinners and / or corrosion inhibitors.

The polymers used for thickening are known per se. These are polyolefins, in particular polyolefin copolymers and hydrogenated styrene-diene copolymers. The polyolefins are preferably composed of ethylene and propylene, but also isoprene, butylene and / or other olefins having 5 to 20 carbon atoms are possible. Preferred polyolefins are copolymers of ethylene and propylene. These often still contain small amounts of dimers (for example of butadiene) and are known to the person skilled in the art under the name EPDM. The average molecular weight of the polymers used according to the invention is preferably in the range from 10,000 to 300,000, in particular from 50,000 to 150,000. Suitable polymers within the meaning of the present technical teaching are described, for example, in WO 2004/03795 on pages 6 to 8. There is also disclosed the thickening effect of such polymers for engine oils.

It is further preferred to dissolve these polymers in a mineral oil or to dispergers ren. Suitable mineral oils preferably have boiling points of 150 to 350 ° C and preferably from 200 ⁰ C and higher, preferably higher than 300 ° C.

In a particularly preferred embodiment of the present invention, the above-described polymers are dispersed together with a dispersant and an emulsifier in a non-aqueous solvent, preferably in mineral oil and added as additives to the drilling fluid in order to increase their viscosity. It is also possible to use mixtures of different nonaqueous solvents.

Suitable dispersants are preferably copolymers comprising one or more blocks A and one or more blocks B, wherein the block A is olefin copolymers, hydrogenated polyisoprenes, hydrogenated copolymers of butadiene / isoprene or hydrogenated copolymers of butadiene / isoprene and styrene, and the Block B contains as polymerized monomers acrylic acid, methacrylic acid, styrene, alpha-methylstyrene or N-vinyl heterocyclic groups and / or mixtures of methyl and / or methacrylic acid, styrene and alpha-methyl styrene. The weight ratio of the dispersing component, in particular the blocks A, to the blocks B can be within wide limits. In general, this ratio is in the range of 50: 1 to 1:50, in particular 20: 1 to 1:20 and particularly preferably 10: 1 to 1:10. The preparation of the above-described dispersing components is known in the art.

Further preferred is the concomitant use of emulsifiers, preference being given to nonionic emulsifiers based on carboxylic acids, carboxylic esters, alcohols or ethers, and in particular their alkoxylated derivatives. However, it is also possible to use phosphoric acid esters or dicarboxylic acid esters.

In any case, the alkoxylated and preferably ethoxylated derivatives of the respective acids, alcohols, ethers or esters are preferred. Preferred carboxylic acids are branched or unbranched monocarboxylic acids having 3 to 18 carbon atoms. In any case, the alkoxylated derivatives are again preferred, especially those containing 1 to 50 and preferably 1 to 20 parts of alkoxide per part of carboxylic acid. The preferred alkoxide is ethylene oxide, but also propylene oxide, iso-propylene oxide and butylene oxide may be suitable. Mixed alkoxides are also possible. Suitable alcohols have 4 to 20 carbon atoms in the molecule and have preferably been reacted with 1 to 50 parts of alkoxide. The emulsifiers are contained in the mixtures with the polymer, the oil and the dispersant preferably in amounts of 2 to 55 wt .-% and in particular from 5 to 45 wt .-% and particularly preferably in amounts of 10 to 40 wt .-% ,

The polymers described above are preferably mixed with polyolefins and optionally formulated in mineral oil or another nonpolar hydrocarbon, and the addition of emulsifiers to an additive.

With regard to the exact composition of these additives, whose use as thickeners in drilling muds is also the subject of the present invention, reference is made to WO 2004/037955, and in particular to the description of pages 6 to 25. A preferred additive for the purposes of the present technical teaching is disclosed on page 27 to page 28 as "Example 1" of WO 2004/037955.

Polymers or their dispersion in oils optionally together with mineral oils and emulsifiers and optionally further ingredients are known as such and are sold, for example, by the company Rohmax / Degussa under the name Viscoplex® 4-677. The use of this commercially available product is expressly part of the present technical teaching.

The polymers or their formulation with polyolefins, mineral oil and emulsifiers are the drilling fluids advantageously in amounts of 0.1 to 25 wt .-%, preferably 1 to 15 wt .-% and in particular from 5 to 10 wt .-%, respectively on the total weight of the oil phase of the rinse, added and lead to a significant thickening of the respective rinse.

A further advantageous embodiment of the present invention comprises the above-described polymers or mixtures thereof with polyolefins and emulsifiers. ren or solvents together with triglycerides, ie full esters of glycerol with suitable carboxylic acids to use for thickening. However, minor amounts of mono- and / or triglycerides as well as free glycerol may still be present in industrially used triglycerides. However, the maximum amounts of these isomers should not exceed 10% by weight, preferably 5% by weight and in particular 2% by weight. Preferred carboxylic acids are saturated or unsaturated fatty acids having 6 to 21 carbon atoms and in particular unsaturated fatty acids, such as oleic acid or linolenic acid. However, the triglycerides should be liquid at 21 ⁰ C to advantageously be used preferably.

Furthermore, it is preferred to use triglycerides based on natural or synthetic fatty acid mixtures. Here, in particular, the refined rapeseed oil (also called rapeseed oil) is of particular importance. Rape oil contains triglycerides of various saturated or unsaturated fatty acids. The following table gives an exemplary overview (in% by weight). The fatty acid composition depends strongly on the type of rape.

The proportion of erucic acid is not significant for the present technical teaching, so that both rapeseed oils with high and low erucic acid content can be used. Other preferred triglycerides are derived from soybean oil or sunflower oil. Preference is generally given to those triglycerides whose fatty acids are at least 50% by weight, based on the total fatty acid content, mono- or polyunsaturated. Soybean oil, for example, has the following composition of fatty acids (values in parentheses represent averages):

For sunflower oils, the following values apply:

All values in the above tables according to Römpp Online, 2005 edition, update 21st August 2005.

Preference is given to mixtures of this type with triglycerides which contain the polymers according to the invention, or their blending with polyolefins, solvents and emulsifiers, in the proportions of 1: 9 to 9: 1 with the triglycerides. Preferred are Mixtures Polymers: Triglycerides from 90:10 to 50:50 and especially from 90:10 to 70:30 and more preferably 75:25.

Also preferred is the use of a mixture of polymers as described above and a triglyceride of saturated or unsaturated fatty acids having 6 to 21 carbon atoms in a ratio of 90:10 to 60:40 as an additive in drilling fluids containing at least 70% by weight of a non-aqueous oil, a weighting agent and a water-soluble salt and optionally emulsifiers, fluid loss additives, alkali reserves, wetting agents, biocides, thinners, corrosion inhibitors.

Drilling muds, which can advantageously be thickened with the polymers described above, preferably contain at most 25% by weight of water, preferably at most 10% by weight of water and especially at most 5% by weight of water, in each case based on the total weight of liquid components. Anhydrous drilling fluids are particularly preferred. In this case, "anhydrous" means that no water is added to the rinses, however, the rinses used in practice may still contain minor amounts of water from the ingredients used, but preferably less than 5% by weight and in particular less than 1% by weight. % Water, in each case based on the total weight of the liquid components of the rinses.

Another object of the present invention relates to borehole treatment compositions containing a non-aqueous oil phase, weighting agents, fluid-loss additives, salts and optionally an aqueous phase, emulsifiers, viscosity-regulating additives, wetting agents, biocides, corrosion inhibitors, and / or an alkali reserve, wherein the non-aqueous phase is wholly or partially selected from the group of a) paraffins having 5 to 22 carbon atoms and / or b) internal olefins having 12 to 30 carbon atoms in the molecule and / or c) carboxylic acid esters of the general formula R-COO- R in which R is a linear or branched, saturated or unsaturated alkyl radical having 15 to 25 C atoms and R 'is a saturated, linear or branched alkyl radical having 3 to 22 C atoms d) mineral oils e) linear alpha Olefins (LAOs) with 12 to 30 carbon atoms. wherein the borehole treating agent contains polymers or additives containing these polymers as described above in amounts of from 0.1 to 25% by weight, based on the weight of the non-aqueous phase.

Preference may be given to drilling fluids whose density of the liquid component is 1.2 to 3.0 g / cm ³ and in particular 1.5 to 3.0 g / cm ³ . The oil phases of the systems according to the invention contain the components a) to e)) alone or the components a), b), d) or e) together in admixture with esters c and optionally in admixture with other suitable oil phases. There are also any mixtures of the oil phases a) to e) with each other possible.

Component a)

As component a) linear or branched paraffins having 5 to 22 C atoms are used according to the invention. Paraffins - more correctly referred to as alkanes - are known to be saturated hydrocarbons which follow the linear or branched representatives of the general empirical formula C _n H _{2n + 1} . The cyclic alkanes follow the general empirical formula C _n H _2n . Particularly preferred are the linear and branched paraffins, whereas cyclic paraffins are less preferred. Especially preferred is the use of branched paraffins. Furthermore, those paraffins are preferred which are liquid at room temperature, ie those having 5 to 16 carbon atoms per molecule. But it may also be preferred paraffins with 17 to 22 carbon atoms, the use of a waxy consistency ways. However, it is preferred to use mixtures of the different paraffins, and it is particularly preferred if these mixtures are still liquid at 21 ° C. Such mixtures can be formed, for example, from paraffins having 10 to 21 carbon atoms.

Component b)

As component b) internal olefins (hereinafter abbreviated to IO) can be used according to the invention. In this case, IOs are also compounds known per se, which can be prepared by all methods known to the person skilled in the art. EP 0 787 706 A1, for example, describes a process for the synthesis of IOs by isomerization of alpha-olefins to sulfonic or persulfonic acids. Characteristically, the IOs so obtained are linear and contain at least one olefinic double bond that is not in the alpha position of the alkyl chain. Preferably according to the invention such IO or IO mixtures used which contain IO with 12 to 30 carbon atoms in the molecule, preferably with 14 to 24 carbon atoms and in particular with up to 20 carbon atoms in the molecule.

Component c)

Furthermore, esters of the general formula R-COO-R ¹ , in which R is a linear or branched, saturated or unsaturated alkyl radical having 15 to 25 C atoms, and R 'is a saturated, linear or branched alkyl radical having 6 to 22 C atoms Atoms means component of the oil phases according to the invention. Also such esters are known chemical compounds. Their principal use in drilling fluids is, for example, the subject of EP 0 374 672 A1 or EP 0 374 671 A1. Particularly preferred is the use of such esters whose radical R is a saturated or unsaturated alkyl radical having 15 to 25 and R ^{1 is} a saturated alkyl radical having 3 to 10 carbon atoms. The saturated compounds are particularly preferred. It is preferred within the scope of the inventive teaching that in the oil phase in addition to the esters as described above a maximum of 15 wt .-% (based on the oil phase) of other esters with radicals R, which are alkyl radicals having more than 23 carbon atoms, are included ,

Component d)

Mineral oils are a collective term for the liquid distillation products obtained from mineral raw materials (petroleum, lignite and coal, wood or peat), which consist essentially of mixtures of saturated hydrocarbons. Preferably, the mineral oils contain only small amounts of aromatic hydrocarbons, preferably less than 3 wt .-%. Preference is given at 21 ° C liquid mineral oils based on petroleum. The mineral oils preferably have boiling points of 180 to 300 ⁰ C.

Component e)

Linear alpha-olefins (LAOs) are unbranched in-situ ("alpha-C-atom") unsaturated hydrocarbons that can be derived from natural products, but are also synthetically derived in large quantities Natural-based LAOs are synthesized by dehydration of natural-based fatty alcohols Products with a straight-chain carbon number, as well as synthetically derived LAO-derived provides by oligomerization of ethylene - often contain straight-chain carbon numbers in the chain, but there are also known methods for the production of odd-numbered alpha-olefins today. For the purposes of the definition according to the invention, owing to their volatility, as a rule at least 10, preferably at least 12 to 14 C atoms in the molecule are present. The upper limit of LAO flowable at room temperature is in the range of C 18-20. However, this upper limit is not restrictive for the usability of this class of substance in the context of the invention. The upper limit of suitable LAO compounds for use in the teaching according to the invention is thus well above the aforementioned limit of C 18-20 and can, for example, reach C30.

In addition to the components a) to e), other water-insoluble constituents may also be present in the oil phases, provided that they are ecologically compatible. Further particularly suitable mixing constituents of the oil phases according to the invention are therefore in detail:

(I) esters of Ci _-5- monocarboxylic acids and 1- and / or polyfunctional alcohols, wherein residues of 1-valent alcohols at least 6, preferably at least 8 carbon atoms and the polyhydric alcohols preferably have 2 to 6 carbon atoms in the molecule .

(ii) mixtures of secondary esters selected from the group of the propylcarboxylate, butylcarboxylate, pentylcarboxylate, hexylcarboxylate, heptylcarboxylate, octylcarboxylate, nonylcarboxylates, decylcarboxylate, undecylcarboxylate, dodecylcarboxylate, tridecylcarboxylate, tetradecylcarboxylate, pentadecylcarboxylate, hexadecylcarboxylate, heptadecylcarboxylate, octadecylcarboxylate, Nonadecylcarboxylate, eicosylcarboxylate, unicocarboxylate, doeicosylcarboxylate and isomers thereof, the secondary esters each having a carboxylate radical having 1 to 5 C atoms, water-insoluble ethers of monohydric alcohols having 6 to 24 C atoms,

(iii) water-insoluble alcohols having 8 to 36 C atoms

(iv) polyalphaolefins (PAO)

(v) Mixtures of component (i) to (iv)

As a further constituent, the drilling fluids according to the invention contain emulsifiers, provided that they are of the emulsion type. When they are selected, it comes divisive to the conditioner. Emulsifiers useful in practice for the formation of W / O emulsions are, in particular, selected oleophilic fatty acid salts, for example those based on amidoamine compounds. Examples of this are described in US Pat. No. 4,374,737 and the literature cited therein. The emulsifiers for forming the drilling fluid may be identical or different from those used in the additives according to the invention itself.

The oil phases of the compositions according to the invention preferably have pour points below 0 ° C., preferably below -5 ° C. (measured in accordance with DIN ISO 3016: 1982-10). The Brookfield viscosity of the oil phases is at 0 ⁰ C at most 50 mPas. The borehole treatment agents of the present invention, when formed as oil-based drilling mud of the W / O type, have a plastic viscosity (PV) in the range of 10 to 70 mPas and Yield Point YP of 5 to 60 lb / 100 ft ² each determined at 50 ° C, on. The kinematic viscosity of the oil phase measured according to Ubbelohde at 20 ° C should preferably be at most 12 mm ² / sec. The aqueous phase of the compositions according to the invention preferably has a pH in the range from 7.5 to 12, preferably from 7.5 to 11 and in particular from 8 to 10.

In addition to the constituents listed above, the compositions according to the invention also contain additives, for example weighting agents, fluid-loss additives, further viscosity-regulating additives, wetting agents, salts, biocides, corrosion inhibitors, and / or an alkali reserve. Here, the general principles for the composition of the respective treatment liquids apply, for which exemplary statements are made below with the aid of corresponding drilling muds. The additives may be water-soluble, oil-soluble and / or water or oil-dispersible.

Classic additives may be: fluid-loss additives, intrinsic viscosity-forming soluble and / or insoluble substances, alkali reserves, means for inhibiting unwanted water exchange between drilled formations - e.g. B water swellable clays and / or salt layers - and the z. B. water-based rinsing liquid, wetting agent for better absorption of the emulsified oil phase on solid surfaces, eg. B. to improve the lubricity, but also to improve the oleophilic closure exposed rock formations, or rock surfaces, biocides, for example, for inhibiting the bacterial infestation of O / W emulsions and the like. Only in part Speaking cited: Fine-dispersing additives to increase the density of the dishwashing liquid: Barium sulfate (barite) is widely used, but calcium carbonate (calcite) or the mixed carbonate of calcium and magnesium (dolomite) are also used.

Means for building up the intrinsic viscosity, which at the same time also act as fluid-loss additives: Bentonite or hydrophobized bentonite should be mentioned here in the first place. For saltwater rinses, other comparable clays, in particular attapulgite and sepiolite, are of considerable importance in practice.

The co-use of organic polymer compounds of natural and / or synthetic origin may also be of considerable importance in this context. Particularly noteworthy here are starch or chemically modified starches, cellulose derivatives such as carboxymethyl cellulose, guar gum, synthangum or purely synthetic water-soluble and / or water-dispersible polymer compounds, in particular of the type of high molecular weight polyacrylamide compounds with or without anionic or cationic modification. Thinner for viscosity regulation: The so-called diluents can be of organic or inorganic nature, examples of organic thinners are tannins and / or quebracho extract. Further examples of these are lignite and lignite derivatives, in particular lignosulfonates.

For the productivity of a petroleum or natural gas deposit, the permeability of the carrier plays a very important role. The initial carrier permeability can be reduced during the drilling work by the drilling fluids used in the drilling near or borehole remote area. This decrease in permeability is called carrier damage. To stabilize the bore and to avoid uncontrolled inflows from the formation, the density of the mud is adjusted so that the hydrostatic pressure of the mud column is above the formation pressure. As a result of the resulting positive differential pressure, solids and / or filtrate of the drilling fluids used can penetrate into the pore spaces of the carrier rock. This can lead to physical and chemical reactions of the penetrated substances with the pore constituents and the carrier rock. The area of the formation damaged by drilling fluids and treatment fluids may be a few centimeters to several meters. Thus, the depth of perforation is usually insufficient to overcome this zone. the. In order to avoid expensive post-treatments to increase the permeability of the carrier, it is necessary to use reservoir-sparing drilling fluids. In addition to conventional requirements, such as high discharge capacity, optimum filtration properties, formation pressure control, electrolyte resistance, cooling and lubrication of drilling tools and environmental requirements, Drilling Fluids demands to limit or completely eliminate permeability-reducing processes (formation damage). For these reasons, the drilling fluids must be able to build very fast a solid, low permeability and good sealing filter cake that can be removed as completely as possible after completion of the drilling activity. As a result, under reflux conditions, permeabilities close to the initial permeabilities should be achieved. In order to assess the effect of such mud systems, it is necessary to study the interactions of the respective drilling mud suspensions with the bedrock.

The use of the additives according to the invention also surprisingly leads to an improvement in the filtrate values of the rinses. A further advantageous property of the additives according to the invention, and in particular the mixtures with triglycerides described above, is an improvement in the lubricating effect of the respective additi fourth drilling fluids.

Examples

example 1

Various drilling muds were prepared and tested with commercial thickeners in combination with a liquid triglyceride, here rapeseed, in terms of their Theological properties.

Product A contained a mixture (for all mixtures applies: in each case 75 parts by weight of thickener and 25 parts of rapeseed oil) of the product Viscoplex® 8-100 with rapeseed oil. Product B contained as Viscoplex® 8-800 (dissolved in mineral oil acrylic polymer) from Degussa with rapeseed oil. Product C according to the invention contained the mixture of rapeseed oil with Viscoplex® 4-677.

The drilling fluid contained a commercially available paraffin oil, an emulsifier of the type of an amidoamine, more precisely the product OMC® 1122 (Cognis) was used as emulsifier. The details of the compositions of the rinses can be found in Table I.

The rheological characteristics of the rinses before (before rolling rolling BHR) and after (after hot rolling, AHR) aging in Roller Oven (each 16 h aging at 250 ° F) are given in Table II. The plastic viscosity (PV), the yield point or yield point (YP) and the gel strength (gels) were measured after 10 seconds and 10 minutes (Gels 10'VIO '). Theological data were always measured according to API Bulletin RP 13 B-2.

Furthermore, the filtrate values (high-temperature-high-pressure fluid loss values "HTHP") according to API RP 13B-2 were determined for compositions 1 and 4. The results are reproduced in Table III. Table I

Table II

Table IH

Example 2

In a further experiment, the lubricating effect of the mixture "C" according to the invention was compared with other products, using a pure paraffin oil as the base oil, which was enriched with 0, 5 and 10% by weight of the additive.

The abrasion was then measured in mm ² with an Optimol SRV lubricant tester with ball at 50 bar and 60 ° C. The results are shown in Table IV:

Table IV

Example 3

The viscosities of a paraffin oil or a mixture of paraffin oil with in each case 10% by weight of a commercially available thickener (product B according to Table I, Dehypar® 587 S, Cognis, Evatane® 28-420, Fa. Atofina ) and for comparison a product C according to the invention according to Table I. Kinematic viscosity measurements were taken with an Ubbelohde viscometer at 60 ° C. The results are shown in Table V.

Table V

Example 4

The dynamic viscosity of blends of the polymer according to the invention with various non-aqueous base oils (mixing ratio 75: 25 m / m) was measured in a Brookfield viscometer. Results in Table VI:

Table VI

It has been found that the mixture according to the invention of the dispersed polymer and the triglyceride has a lower viscosity than blends with other liquids. The handling of the product according to the invention is therefore better than that of other blends.

Claims

claims

1. Use of polymers selected from the group of olefin polymers of ethylene and propylene, hydrogenated polyisoprenes, hydrogenated copolymers of butadiene and isoprene, and / or hydrogenated copolymers of butadiene, isoprene and styrene, optionally in admixture with a nonaqueous solvent, a dispersant and emulsifiers, as thickeners in drilling muds containing at least 70% by weight of a nonaqueous oil, a weighting agent and a water-soluble salt and optionally emulsifiers, fluid loss additives, alkali reserves, wetting agents, biocides, thinners and / or corrosion inhibitors contain.

2. Use according to claim 1, characterized in that the polymers are dissolved or dispersed in a mineral oil.

3. Use according to claims 1 to 2, characterized in that as dispersants copolymers comprising one or more blocks A and one or more blocks B, wherein the block A Olefincopolymerisate, hydrogenated polyisoprenes, hydrogenated copolymers of butadiene / isoprene or hydrogenated copolymers from butadiene / isoprene and styrene and the block B contains as polymerized monomers acrylic acid, methacrylic acid, styrene, alpha-methylstyrene or N-vinyl heterocyclic groups and / or mixtures of acrylic acid, methacrylic acid, styrene, alpha-methyl styrene.

4. Use according to claim 1 to 3, characterized in that the polymers have an average molecular weight M _w of 10,000 to 300,000 Da.

5. Use according to claim 1 to 4, characterized in that the polymers, optionally in combination with the solvent, the dispersant and the emulsifier in amounts of 0.1 to 25 wt .-%, preferably 1 to 15 wt. % and in particular from 5 to 10 wt .-%, in each case based on the total weight of the oil phase of the rinse.

6. Use according to one of claims 1 to 5, characterized in that the polymers are used in drilling muds, the highest 25 wt .-% water, preferably at most 10 wt .-% water and in particular at most 5 wt .-% water, respectively based on the total weight of liquid components.

7. Use according to claims 1 to 6, characterized in that the polymers are used as an additive in combination with a dispersant, an emulsifier and at least one non-aqueous solvent.

8. Use according to claims 1 to 7, characterized in that the polymers are used together with triglycerides of saturated or unsaturated fatty acids having 6 to 21 carbon atoms.

9. Use according to claim 8, characterized in that as a triglyceride refined rapeseed oil is used.

10. Use of a mixture of polymers as described in claim 1 and a triglyceride of saturated or unsaturated fatty acids having 6 to 21 carbon atoms in a ratio of 90: 10 to 60: 40, as an additive in drilling muds containing at least 70 wt .-% of a non-aqueous oil, a weighting agent and a water-soluble salt and optionally emulsifiers, fluid loss additives, alkali reserves, wetting agents, biocides, thinners, corrosion inhibitors.

11. Borehole treatment compositions containing a non-aqueous oil phase, weighting agents, fluid-loss additives, salts and optionally an aqueous phase, emulsifiers, viscosity-regulating additives, wetting agents, biocides, corrosion inhibitors, and / or an alkali reserve, wherein the non-aqueous phase is wholly or partly is selected from the group of a) paraffins having 5 to 22 carbon atoms and / or b) internal olefins having 12 to 30 carbon atoms in the molecule and / or c) carboxylic acid esters of the general formula R-COO-R in which R is a linear or branched, saturated or unsaturated alkyl radical having 15 to 25 carbon atoms and R ^{1 is} a saturated, linear or branched alkyl radical having 3 to 22 C -Atomen means d) mineral oils e) linear alpha-olefins (LAOs) having 12 to 30 carbon atoms, characterized in that the borehole treatment agent polymers according to claim 1 in amounts of 0.1 to 25 wt .-%, by weight the non-aqueous phase contains.

12. borehole treatment agent according to claim 11, characterized in that the density of the liquid components 1.2 to 3.0 g / cm ³ and preferably 1.5 to 3.0 g / cm ³ .