Note: Descriptions are shown in the official language in which they were submitted.
2 ~ -~3 ~ n ''~
Henkel ~GaA
Dr. FU/ku
07.12.19
P a t e n t A p p 1 i c a t i o n
D 8636
~'Agents for increasing viscosity in non-aqueous liquid phases,
processes for their production and their use"
_________________________________________________ _____________________
The invention relates to new possibilities for influencing and
controlling the rheology of non-aqueous liquid phases and enables in
particular a controlled increase in viscosity in liquids of this type.
The predeterminable regulation of the rheological behavior of non-
aqueous liquid phases is of considerable iTFortance in ~any fields of
technology. An important example is in the currently widely used non-
aqueous drilling fluids based on so-called invert drilling fluids,
which contain a dispersed aqueous phase in a continuous oil phase. An
Important area of application for such drilling fluid systems is in
off-shore wells for the development of petroleum and/or natural gas
deposits. Tbday, however, such W/O-emulsions are put to quite
general use as drilling-mud systems in land-based drilling, for
example, in geothermal wells, water bore-holes, in the drilling of
geoscientific bores and in drilling for the mi~ing industry.
In an important embodiment, the invent:ion relates to improved drilling
fluids of this type of W/O-invext system, and therefore reference is
made below to this area of application in particular, although the
invention is in no way limited thereto.
In current practice, hydrophobized layered silicates of the bentonite
group are used a~ the rheology-regulating additives for non-aqueous
drilling fluids. Such products are ccmmercially available, for
exa~ple, under the collective name ~Bentones". The surface
hydrophobization necessary for incorporation into~the slightly polar to
non-polar carrier fluid i8 usually carried out with quaternary ammonium
~altQ, the organic cations of which combine by m0an_ of electro~tatic
interactions with the negatively charged layered-silicate pl~telets.
Such product are indeed industrially satisfactory, hut from ecological
point of view they mus~ be regarded a~ problematic: the quaternary
ammonium salts used for the hydLophobization generally exh~bit biocidal
effects, and as a result the po~sibility of envlronmental damage cannot
be ruled out.
...
i:
;': '
- 2 ~ 7~
The invention begins with the problem of preparing substitutes which
are ecologically less harmful, but are at least of the same value in
industrial practice, for influencing and controlling the rheology of
such non-aqueous li~lid phases. The technical solution of this problem
begins with the knowledge that selected inorganic la~ered materials
with a positive layer charge (inorganic polycations), which have been
brought tO interaction with mono- and/or polybasic acid anions of
marked oleophilic character, produce results, when used as rheology-
regulating additives, at least of the same value as the hydrophobized
bentonite oompounds used previously.
The subject of the invention is accordingly constituted in a first
embodin:nt by agents for influencing the rheology, in particular for a
controlled increase in the viscosity, of non-aqueous liquid phases
based on hy~drophobic oil-dispersible mixed hydro~ide oompounds with an
inorganic basic structure, such that the characterizing part for the
invention is that these agents are formed at least partly by finely
dispersed particles of inorganic layer compounds with a positive layer
charge based on two-dimensional inorganic polycations (polycationic
layer compounds) and monobasic and/or polybasic acid anions of marked
oleophilic character.
Two-dimensional inorganic polycations with inner-crystalline charge
equalization via mobile interstitial anions are also known as "double-
layer hydroxides" and are described in many places in the literature.
See, for example, R. Allmann, "Doppelschichtstrukturen mit
brucitahnlichen Schichtionen ...", Chimia 24, 99 to 108 (1970).
Chemically these compounds are mLxed hydroxD salts of di- to trivalent
metal ions and can be characterized by the general formula
M(II)1_~M(III~X(CH)2A~ n H20
in which
M (II) represents at least one divalent metal ion,
M (III) represents at least one trivalent metal ion and
A represents an equivalent of a mono- and/or polybasic acid
~d
x sig~ifies a number from 0.01 to 0.5 and
n signifies a number o~ 0 to 20.
S~me of the properties of this cla~s of oompound~, e.g., their us~ ~s a
catalyst material, as an ion exchanger and for some medical
applications were summarized ~y W.T. Reichle ~Anionic Clay Minerals",
CHE~IECH, J~n. 1986, p. 58 to 63). Variou~ pDssibilities for the
industrial prcduction of the8e cc~p~unds are given in DE-OS 20 61 156.
A well characterized repre~n~ative of thi8 gr~up of sub8tance8 i8 the
~ . .
:
- 3
7 ~
naturally occurring, but also synthetically producible hydrotalcite, a
magnesium-aluminium-hydroxocarbonate of the approximate ccmposition
Mg6A12(OH)16CO3 . 4H20, the structure of which was determined by
X-ray photography (R. Allmann and H.P. Jepsen, "Die Struktur des
Hydrotalkits", N. Jahrb. Mineral. Monatsh. 1969, p. 544-5S1).
The modification of hydrotalcite-like layered compounds by treatment
with anionic surface-active agents is also known. For example, DE-PS
19 632 mentions that hydrotalcite treated in this way is
particularly suitable for the stabilization of halogen-containing
synthetic materials. The use according to the invention of the
reaction products of inorganic polycationic layered materials with acid
anions of a marked oleophilic character for influencing and controlling
the rheolcgy of non-aqueous liquid phases, in particular in the sense
of a controlled increase in viscosity, is not, however, anticipated by
this patent.
EP-OS 207 811 describes the use in aqueous drilling fluids of non-
hydrophobized mixed metal hydroxides which are produced in a
particularly finely particulate form by an expensive process. In
contrast, the aim of the invention is to influence the rheology of
particularly the non-aqueous liquid phases. The hydrophobization
provided according to the invention of the polycationic layer compounds
through the incorporation of mono- andtor polybasic acid anions of
marked oleophilic character into the polycationic inorganic material is
required for this.
The mixed hydroxo salts of divalent and trivalent metal ions provided
according to the invention make , in the form m3dified according to the
invention, hydrophQbic finely dispersed solids of the following general
formula I
M(II)1_~M(III)X(OH)2A~ n H20 (I)
in which
M(II) represents at least one divalent metal ion
M(III) represents at least one trivalent metal ion and
A represent an equivalent of anions o~ mono- and/or
poly~asic acids at least partly of a marked oleophilic
character
an~
x signifi~ a number from 0.01 to 0.5 and also
n signifies a number frcm 0 to 20,
such that at least such a part of the radical A i9 derived from
oorresponding acids of marked oleophilic character that the ~olids of
.~ .
.
;,
2 ~ i` q
- 4 -
the general formula 1 are hydrophobic.
Hydrophobic behavior already appears on the incorporation of 2 to 3 %by weight (referred to the total quantity of solid) of an acid anion of
marked oleophilic character.
A solid is understood to be hydrophobized in the sense of theinvention, when more than 90 % thereof disperses in the oil phase in
the following test: 1 g of the test substance is placed in a 100-ml
glass b~aker in 50 ml of totally deionized water. m e aqueous phase is
provided with a layer of 5 ml of silioon oil (for example, the
cammercial product ~Baysilon 100" of the ooTpar.y BAYER AG) and the tw~
phases are intermuxed by stirring with a magnetic stirrer. The
hydrophobic part of the solid disperses in the oil phase, which when
there is a high solids charge can clump together and sink to the
bott~m.
The divalent metal ions M(II) frGm formula I are fon~ed in aparticularly preferred emtDdlment of the teaching according to the
invention ~y magnesium, calcium, barium or zinc or any mixtures
thereof. I~he invention is not, however, limited thereto. In
principle, any divalentimetal ions cani~e used, as disclosed in a wider
context, for example, in the already cited EP-OS 207 811.
In the context of the present invention, the preferred metal ionsM(III) ~rom the ocmpounds of steneral formula I are aluminium and/or
iron. It is also true here that these trivalent metal ions can be used
in the wider context as disclosed, for example, in the a'cove E~lropean
Patent Application.
According to the invention the radical A fram the general fonmula I,which is formed at least partly by the hydrophobizing acid radicals, is
particularly important. m ese are anions of oleophilic organic
o3mpounds with at lea t one salt~forming acid s~roup. A suitable acid
gxoup of this type is the carboxyl group. The invention i8 not,
however, limited thereto. In addition to, or in pla oe of, such
carboxylic acid radicals, radieals of hetero-organic acids are also
suitable, and in particular heterc-organic acids based on sulphur
and/or phosphoru3 can be considered. me following also applies here:
The acid grouping, with the respective nucleus of the acid grou~ can beattached ~;rectly ~o tha oleophiLic ba~ic structure. In particular in
the ca6e of polybasic acid groups, the anion-forming acid radical can
Ln any case also ~e linked by means of hetero atoms - for example,
oxygen - to the oleophilic organic radical. ThiR latter embodimen:t iS
ignifiCant Ln particular for polybasic acids such a~ sulfonic acids or
_ 5 2 ~ 3
phosphonic acids, which can then also be used in the fonm of their
acidic esters of marked oleophilic character.
It is generally the case that, in preferred embodlments, the agentsaccording to the invention of the general formula I are compounds in
which the hydrophobizing anionic acid radicals A derive from compounds
R-X (IIa) and/or from oompounds of the formula R-C-Y (IIb); the
following applies for these tWD general formula~:
R represents a markedly oleophilic hydrocarbon radical with preferablyat least 6 carbon atoms, X represents the anionic radicals of the acid
grouping, which can preferably be derived from -COOH, -$O3H and/or -
PO3HR~. Y in a possible embodiment is the anionic radical of -SO3H or
-PO3HR~, and finally in these cases R can signify a hydrogen radical
or a hydrocarbon radical - particularly an alkyl radical - with, for
example, up to 20 carbon atoms.
Particularly suitable acid anions A from the general formula I derivefrom acids which fall under the general formulae IIa and/or IIb, in
which the radical R represents a linear or branched, saturated or
unsaturated alkyl and/or arylalkyl radical. Ihese pure hydrocarbon
radicals can also be substituted. Suitable substituents are in
particular hydroxyl, thiol andtor a~ino groups. It is particularly
preferred ~or the radical R to represent hydrocarbons of the
aforementioned type with 8 to 36 car~on atoms. In particular,
oorresponding carboxylic acids of natural and/or synthetic origin can
be suitable here, and carboxylic acid mLxtures of natural origin can be
of particular significance. Without exception these are hydrophobizing
anionic radicals A in the general formula I which derive frcm
environmentally acoeptable ccmpounds of low toxicity and therefore are
particularly suitable for this aspect of the objective of the
invention.
In a further embodiment the invention includes processes for theproduction of the aforementioned agent and in particular of finely
dispersed oampounds of the general formula I. In principle there are
several possible methods:
In a first embodhnYnt, polycationic layer compounds of the above typeare initially produced in a manner known per se, in which hcwever the
inner-crystalline charge equalization is effected by anions, which
differ in thp;r constitution from the anionic radicals A from general
formula I a defined acoording to the invention. ~oth inorganic and
organic acid radicals can be oonsiderad here and in gener~l the salt-
forming acid radicals fram the metal salts used for the synthesis of
the double-layer hydroKides are present. In a subsequent reaction the
6 - 2~ n~ 1
mlxed hydroxide compounds initially formed, are treated with the
selected ~ono- and/or polybasic acids of marked oleophilic character
and/or their salts soluble in the reaction medium. At least a covering
hydrophobization of the polycationic inorganic layered materials occurs
on interchange of salt. Hydroxo salts of this type are then oil-
dispersible and can be used for rheology control in the sense of the
invention.
This subsequent hydrophobization of the previously formed cationiclayered cc~pounds is, however, only one possibility for the preparation
of agents for the application according to the invention. More
favorable alternatives consist in carrying out the production of the
mlxed metal hydroxo salts directly in the presence of the
hydrophobizing acids or acid anions.
In one emkcdiment of the invention, with the aid of liquid phases, e.g.the follc~ing method is used : An alkalized solution of the
hydrophobizing acid, e.g. of an alkanic acid or an alkanic acid
mixture, is mixed with a solution of the divalent and trivalent metal
cations in the necessary molar ratio. As the liquid phase, or solvent,
water and~or aqueous organic liquid phases can be used. The mixed
hydroxo salt is then formed in this system in a manner known per se, by
heating. Detailed specifications for the formation of double-layer
hydroxides of the type referred to here can be found in the cited prior
art.
A further and particularly suitable synthesis method consists in thereaction of the hydroxide or hydroxides of one metal cc~ponent(s)
thus, for example, of the divalent mLtal cc~ponent - with an easily
meltable salt of the other metal component(s) required in the melt,
such that these latter named metal salts already contain the mono-
andJor polybasic acid anions of a marked oleophilic character as salt-
forming components. After the reactants have reacted in the nelt, the
c~oled melt is then ground to pGwder.
In a furth~r embodiment the invention includes the use of the agentdescribed a~ove in non~aqueous liquid phases, particularly as a
structure form~r and viscosity regulator. It is particularly important
in the context of the invention to use this agent as a rheology-
nndifying agent in W/O invert dr;lling fluids with a continuous oil
phase and a dispersed aqueous phase.
Fin lly, W/O invert drilling fluids of the latter type fall within thescope of the inYention which are characteriæed in that they contain as
a rheology-mDdifying agent a~ lea~t partly the æ orementioned agents of
the invention, in particular tho~e of the general formula I. For
2 ~
the structure, the nature and the req~lireTent-profile of such invert
drilling fluid systems, refer to the relevant prior art. Drilling
fluids of this type consist of a 3-phase system: oil, water and finely
particulate solids. For the stabilization of the aqueous phase which
is finely dispersed in the continuous oil phase, and for the
stabilization of the total system as well as for the adjustment of the
desired application properties, a number of a~;tives are provided,
particularly emulsifiers, weighting agents, fluid-loss additives,
alkali reserves, viscosity regulators and the like. For details see,
for example, the publication by P.A. Boyd et al. "New Base Oil Used in
Low-Tbxicity Oil Muds" Journal of Petroleum Technology, 1985, 137 to
142 and R.B. Bennett "New Drilling Fluid Technology - Mineral Oil Mud"
Journal of Petroleum Technology, 1984, 975 to 981 and in the literature
cited therein.
Selected diesel oil fractions are used as the oil phase, and inparticular increasingly in recent times pure hydrocar~on oils which are
at least largely free from aromatics. The relevant technology has for
some time recoc~nized the significance of the environmental problems
triggerecl by these oil phases. This explains the increased
significance of the oil-base muds based on so-called non-polluting
oils. In adclition to the mineral oil fractions free frcm aromatics,
oil phases based on esters in particular belong to the class of non-
polluting oils. Ester oils, or invert drilling-mud systems based on
ester oils, which are usable and distinctly improved particularly fm m
the point of view of environmental protection, are the subject matter
of a number of the Applicant's earlier Applications. See here in
particular the Applications P 38 42 659.5 and P 38 42 703.6, the
earlier Patent Applications P 39 07 391.2 and P 39 07 392.0 and th~
associated further development of such invert drilling fluids based on
ester-oils in the Applicant~s earlier Application P 3~ 03 785.1. The
disclosure of all these earlier Applications is in principle also valid
for the modification described in the present invention, the subject
m~tter of which is the replacement of the structure-formlng gel-forming
agent. The disclosure of these named earlier Applications as to the
basic nature of such W/O invert drilling fluids i9 hereby expressly
included in the subject matter of the present invention disclosure.
Finally, the earlier A~plications P 39 11 238.1 and P 39 11 299.3should also be oonsidered in this context, which likewise refer to
new systems on a WJC-base for application in drilling fluids and are
characterized by improved environmental acceptability. m e structure-
forming ~elling agents described aco~rding to the invention can be used
to advantage in all these materials.
The quantity of visoosifier used acco~ding to the invention oorresponds
- 8 - 2~ ;,/7
approxLmately to the quantities of the previously used oorponents based
on cation-modified finely particulate bentonites. ~dditional
quantities are therefore suitable in particular in the range of acout
0.5 to 5 % by weight, preferably in the range of about 0.8 to 3.5 % by
weight, referred to the oil phase.
The following also applies:
Invert drilling muds of the type referred to here usually contain,
together with the continuous oil phase, the finely dispersed aqueous
phase in quantities from about 5 to 45 ~ by weight and preferably in
quantities from about 10 to 25 ~ by weight. Particular significance
can be attributed to the range from about 10 to 25 % by weight of
dispersed aqueous phase.
The following rheologiQl data apply for the rheology of the invert
drilling fluids preferred according to the invention: Plastic
viscosity (PV) in the range from a~out 10 to 60 mPa.s, preferably from
about 15 to 40 mPa.s, yield point YP) in the range from about 5 to 40
lb/100 ft2, preferably from about 10 to ~5 lb/100 ft2 _ each determined
at 50C. For the determination of these parameters, for the measuring
methods used therein and for the rest of the usual composition of the
invert drilling fluids described here, the details apply as in the
prior art, cited above and described in detail, for example, in the
"Manual of Drilling Fluids Technoloqy" of the CQmpany ML Baroid,
London, GB, and in particular under the chapter "Mud Testing - Tbols
and Technique~" and "Oil Mud Technology" which is freely accessible to
interested experts. In sumnary for the purposes of completion of the
invention disclosure the follc~ing can be said:
The emulsifiers that can be used in practice are syst~ms suitable for
the formation of the required ~/O-emulsions. In particular, selected
oleophilic fatty acid salts, e.g. those based on amidoam m e compounds,
can be considered.
Examples of these are described in US PS 4,374,737 and the literature
cited therein. A particularly suitable type of emLlsifier is the
product sold by the cc~pany NL Baroid under the brand name "EZ-mul".
Emulsifiers of this type are sold crmmercially as hic~hly-concentrated
acti~e substan oe preparations and can, for e~ample, be used in
amounts from about 2.5 to 5 % by weight, particularly in amounts from
about 3 to 4 ~ ~y ~eic~ht - referred to the oil phase.
~ydrophobized lignite particularly is used in practice as the fluid-
1068 additive and thus in particular to form a d~n6e ooating -of a
: ,
.
.,
.,
~ ~ ~ 7 !~ q
_ 9 _
largely liquid-impermeable film on the bore-hole ~alls. Suitable
amounts lie in the range, for example, frQm about 15 to 20 Ib/bbl or
from about 5 to 7 ~ by weight, referred to the oil phase.
Barite is the weighting agent generally used in relevant applications
to establish the necessary pressure compensation, the amounts added
being varied according to the drilling conditions to be anticipated in
each case. By adding barite, it is, for example, possible to raise tne
specific weight of the drilling fluid to 2.S and preferably to a value
in the range of about 1.3 to 1.6.
The dispersed aqueous phase in these invert drilling fluids is loaded
with soluble salts. Calcium chloride and/or potassium chloride are
used predaminantly here, saturation of the aqueous phase at room
temperature with the soluble salt being preferred.
The aforementioned emulsifiers, or emulsifier systems, optionally also
serve to improve the oil wettability of the inorganic weighting
materials. In addition to the amL~Damides already mentioned, further
examples are alkylbenzene sulfonates and imidazoline conpounds.
Additional information regarding the relevant Prior ~rt can be found in
the following publications: GB 2 158 437, EP 229 912 and DE 32 47 123.
:
7 ~
-- 10 --
E x a m p 1 e s
Example 1
200 g of coTmercial hydrotalcite is suspended in one liter of i-
propanol. 132 g of lauric acid is dissolved as far as possible in one
liter of i-propanol and added to the hydrotalcite suspension. The
resulting suspension is stirred for four hours at -oom temperature and
then refluxed for one hour. Afterwards the solids are îiltered off,
washed with i-propanol and dried at 110C in the drying cabinet.
Example 2
200 g of cG~mercial hydrotalcite is suspended in one liter of i-
propanol. 187 g of stearic acid is dissolved as far as possible in one
liter of i-propanol and added to the hydrotalcite suspension. me
resulting suspension is stirred for four hours at room temperature and
then refluxed for one hour. Afterwards the solids are filtered off,
washed with i-propanol and dried in the drying cabinet at 110C.
Example 3
315.5 g of an industrial colza-oil/split fatty acid mlxture is mLxed
and stirred with 400 g of o~mmercial hydrotalcite. The semi-solid,
crumbly product is after-dried in the drying cabinet at 110C.
Example 4
1S5.6 g of an industrial colza-oil/split fatty acid mLxture i6 mixed
and stirred with 400 g of oom~ercial hydrotalcite. The semi-solid,
crumbly product is after-dried in the drying cabinet at 110C.
EKamPle 5
A mLXture of 22.5 g of Al(OH)3 and 100 g of zinc stearat~ is melted at125 to 130C and held for an hour at this temperature. ~he oooled
solidified melted material is then ground to powder.
Example 6
100 g of ocmmercial hydrotalcite is suspended in one liter of water ~nd
67.2 g of dodecyIbenzenesulfonic acid i8 add~d. The suspension i~
stirred for one hour at room temperature, the solid matter i8 drawn
off, washed with water and dried.
Example 7
1800 ml of water i9 mlxed with 200 g of an industrial colza-oilJsplit
fatty acid mixture and with 500 g of a 50 ~ by weight sodium hydroxide
solution. A solution of 230 g of magnesium nitrate/hexahydrate and 169
g of aluminium-nitrate-nonahydrate in 630 g of water is allowed to drop
into this muxture under stirring at room temperature (fcam formationl).
After the addition is complete, stirring is continued for four hours at
65C, the solid matter was drawn off, washed with water and dried at
110C in the drying cabinet.
Ex1mple 8
A solution is prepared of 410 g of magnesium nitrate/hexahydrate and300 g of aluminium nitrate/nonahydrate in 8000 g of totally deionized
water and a second solution is prepare from 448 g of 50 ~ sodium
hydroxide solution and 160 g of scdium car~onate (water free) in 8000 g
of totally deionized water. The two solutions are pumped with
peristaltic (hose) pumps through the leg of a Y-shaped tube into a
receiver, the hydrotalcite precipitate fonmed is dra~n off and washed
with totally deionized water. m e pasty product with a solids content
of a maximu~ of 70 ~ (determlned by drying at 110C) is not dried
further so that the fine primary particles do not aggl~merate further.
100 g of the acove paste with a solids content of about 25 % by weight
is suspended in 250 ml of fully deionized water and mlxed at room
temperature with 2.5 g of phosphonoacetic acid monoethylester. The
mlxture is stirred, filtered, washed ~ith water and dried at 110 in
the drying cabinet.
Example 9
100 g of the hydrotalcite paste from Example 8 is suspended in 250 ml
of fully dei~niæed water and muxed at room temperature with 5 g of 12-
hydroxystearic acid. The mixture is stirred for one hour at room
temperature, filtered, washed with water and dried at 110C in the
drying cabinet.
Example 10
Rheology-regulating additive~ according to the invention and
state-of-the-art comparati~e produ~ts were tested in a diesel drilling
fluid with the follcwing formulation:
168 g diesel oil
6 g W/0-emLlsifier ~"Invermul~ of the oompany NL Baroid)
- 12 - `` ' "`' `~
3 g lime
6 g organophilic lignite ("Duratone" of the ooTpany NL Bar~id)
3 g W/0-emulsifier ("EZ-mul NT" of the coTpany NL Baroid)
73 g CaC12-solution
470 g barite
____________________
2 g rheology-regulating additive according to the table below
As the test parameters, the following were measured: Plastic viscosity(PV) in cP and yield point (YP) in lb/100 ft2 and the gel streng~h (GS)
in lb/100 ft2 for 10 sec. and 10 mun., in which in each case the first
figure in the table refers to the value after the production of the
fluid, the seoond figure refers to the value after ageing (16 hours) at
250F.
Additive from
Example No. PV YP GS
___________.________________________________________________________
1 41 / 3510 ~ 7 4;5 ~ 4;6
2 43 / 361~ / 13 5;6 / 5j6
4 42 / 4114 / 11 5;6 ~ 5;6
43 / 4310 / 11 4;5 / 5;6
6 42 / 42~ / 11 4;5 / 5;7
7 43 / 4311 / 8 5;6 / 5;6
8 40 / 351~ / 11 4;4 / 4;5
9 41 / 411~ / 14 4;4 ~ 5;6
Geltone II
(oomparison) 50 / 453'3 J 39 15;18 / 15;19
Cmnigel
(oomparison) 47 / 4419 / 41 8;11 / 16;21
Perchem
(comparison) 50 / 4521 / 42 8;10 / 16;20
.
,
.~ .
