Note: Descriptions are shown in the official language in which they were submitted.
33
OIL BASE FLUIDS CONTAINING ORGANOPHILIC CLAYS
This invention relates to organophilic organic-clay
complexes which are dispersible in organic liquids to form
a gel therein. More particularly such gels are useful in
oil base muds and oil base packer fluids.
It is well known that organic compounds containing
a cation will react with clays which contain a negative
layer-lattice and exchangeable cations to form organo-
philic organic-clay products. The reaction of an organic
cation containing at least one alkyl group of at Least 10
carbon atoms with clay generally results in organoclays
swellable in certain organic liquids.
Prior publications include U S. Pat. No. 2,531,427,
and U.S Pat No 2,966,506 and the book "Clay Mineralogy",
2nd Edition, 1968 by Ralph E. Grim (McGraw Hill Book Co ,
Inc.), particularly Chapter 10, Clay-Mineral-Organic
Reactions; pp. 356-368 - Ionic Reactions, Smectite; and
pp. 392-401 - Organophilic Clay-Mineral Complexes
Maximum gelling (thickening) efficiency from these
organoclays is achieved by adding a low molecular weight
polar organic dispersing material to the composition.
Such materials are disclosed in U S. Patents: O'Halloran
2,677,661; McCarthy et al. 2,704,276; Stratton 2,833,720;
Stratton 2,879,229; and Stansield et al 3,294,683 The
use of such dispersion aids was found unnecessary when us-
ing particular organophilic clays derived from substituted
-2- ~6~3
quaternary ammonium compounds as disclosed in Finlayson et
al 4,105,578 and Finlayson 4,208,218.
Prior organophilic clays have exhibited limited
broad range gelling utility due to fluctuating dispersion
and viscosity properties. While the materials disclosed
in U.S. Patent 4,105,578 have not shown such deficiencies,
such materials are difficult and costly to produce.
Summary of the Invention
An oil-base fluid of this invention which com-
prises an oil phase and from about 1 to about 50 lbs. per
barrel of the fluid of an organophilic gellant comprising
the reaction product of an organic cationic compound, an
organic anionic compound and a smectite-type clay having a
cation exchange capacity of at least 75 milliequivalents per
100 grams of said clay.
Detailed Description of the Invention
The oil base fluid of the present invention consists
of an oil phase and from about 1 to about 50 lbs. per barrel
of fluid of an organophilic clay gellant. Preferably, the
fluid is non-aqueous. A suitable oil phase of this invention
may be crude petroleum and fractions thereof, including but
not limited to diesel oil, kerosene, fuel oil, light lubri-
cating oil fractions, and heavy naptha having a boilingrange between about 300F to about 600F. The preferred oil
phase material is diesel oil.
The a~ount of the organophilic clay employed
should be effective to obtain the necessary degree of
gellation (thickening) of the oil-base fluid for the intended
application, that is, drilling fluid or packer fluid. The
minimum concentration of organophilic clay needed to gel a
particular fluid is dependent upon factors such as the type
of organophilic clay used, the characteristics of the oil
phase, the maximum temperature to which the fluid is to be
raised, and the type of emulsifier, if any. The maximum
concentration of organophilic clay is limited to that which
will form a pumpable fluid.
The concentration of organophilic clay within the
range of about 1 to about 50 lbs. per barrel (42 gallon
~6~033
--3--
barrel of fluid) will generally provide a sufficiently
gelled fluid for broad applications. Preferably about 1 to
about 10 lbs. per barrel are employed in the preparation of
oil-base drilling fluids whereas amounts from about 6 to 50
lbs. per barrel have been found adequate for the preparation
of oil-base pac~er fluids. It has been found that when the
organophilic clay is mixed into the oil-base fluid, essen-
tially complete gelling is achieved at low shear mixing.The resulting oil-base fluid is a stable oil-base fluid at
surface temperatures below -20F and downhole temperatures
up to 500F. The formation of the stable fluid occurs in a
matter of minutes following addition and low shear mixing of
the organophilic clay in the oil base fluid.
A packer fluid is prepared in accordance with
this invention by adding to an oil medium the organophilic
clay. The composition of the packer fluid is regulated as
discussed above to provide a pumpable composition. Optional
emulsifiers, weighting agents, and fluid loss control
materials may be added at any time. Once prepared, the
packer fluid is transferred, such as by pumping, into a well
bore, at least one portion of which is to be insulated.
The oil-base fluid can be prepared and used either
before drilling commences or while drilling is in progress.
The method of adding the ingredient to prepare the fluid
is not critical. Mixing is accomplished with conventional
devices capable of developing a low shear mixing force.
Greater mixing force may be employed even though not
necessary. Once prepared, the emulsion drilling fluid is
transferred, such as by pumping, into a well bore and
circulated to the bit and through the borehole in contact
with the walls thereof.
The organophilic clays of this invention can be
prepared by admixing the clay, organic cation, organic anion
and water together, preferably at a temperature within the
range from 20C. to 100C., more preferably 35C. to 77C.
for a period of time sufficient for the organic cation and
organic anion complex to intercalate with the clay particles.
The mixing step is followed by filtering, washing, drying
_4_ ~ 3
and grinding. The addition of the organic cation and
organic anion may be done either separately or as a complex.
In using the organophilic clays in emulsions, the drying and
grinding steps may be eliminated. When admixing the clay,
organic cation, organic anion and water together in such
concentrations that a slurry is not formed, filtration and
washing steps can be eliminatecl.
The organophilic clays of the invention may also
be prepared by admixing the organic anion with an aqueous
clay slurry preferably at a temperature between 20C.
and 100C. for a sufficient time to prepare a homogenous
mixture followed by the addition of the organic cation in
sufficient amounts to satisfy the cation exchange capacity
of the clay and the cationic capacity of the organic anion.
The mixture is reacted with agitation at a temperature
between 20~C. and 100C. for a sufficient time to allow the
formation of an organic cation-organic anion complex which
is intercalated with the clay and the cation exchange sites
of the clay are substituted with the organic cation.
Reaction temperatures below 20C or above 100~C, are
not preferred due ~o the need for additional processing
eguipment.
The organic cationic compounds useful in this
invention may be selected from a wide range of materials
that are capable of forming an organophilic clay by exchange
of cations with the smectite-type clay. The organic cationic
compound should have a positive charge localized on a single
atom or on a small group of atoms within the compound.
Preferably the organic cation is selected from the group
consisting of quaternary ammonium salts, phosphonium salts,
sulfonium salts and mixtures thereof wherein the organic
cation contains at least one linear or branched alkyl group
having 8 to 60 carbon atoms. More preferably, the organic
cation contains one member selected from a first group
consisting of a ~,y - unsaturated alkyl group having less
than 7 aliphatic carbon atoms, a hydroxyalkyl group having 2
to 6 carbon atoms, and an aralkyl group and mixtures thereof
and a second member selected from a second group consisting
-5- ~L6~3
alkyl group. More preferably, two additional members of
the compound are individually selected from a third group
consisting of a ~, Y-unsaturated alkyl group having less
than 7 aliphatic carbon atoms, a hydroxyalkyl group having 2
to 6 carbon atoms, an aralkyl group, an alkyl group having
from 1 to 22 carbon atoms and mixtures thereof.
The organic cation may be selected from a
group consisting of the formulae:
R1
R4 X R2
R3
and
R2 Y R4
wherein X is nitrogen or phosphorus, Y is sulfur, R1 is an
alkyl group having 8 to 60 carbon atoms; and R2, R3 and
R4 are individually selected from the group consisting of
hydrogen; hydroxyalkyl groups having 2 to 6 carbon atoms;
alkyl groups containing 1 to 22 carbon atoms; aryl groups;
aralkyl groups containing 1 to 22 carbon atoms on the alkyl
chain; and mixtures thereof. Preferably, X is nitrogen.
The long chain alkyl radical may be branched or
unbranched, saturated or unsaturated, substituted or unsub-
stituted and should have from 8 to 60 carbon atoms in thestraight chain portion of the radical. Preferably, R1 is
an alkyl group having 12 to 6n carbon atoms. More preferably,
R1 is an alkyl group having 12 to 22 carbon atoms.
The long chain alkyl radicals may be derived from
naturally occurring oils including various vegetable oils,
~G~3~333
--6--
such as corn oil, coconut oil, soybean oil, cottonseed oil,
and castor oil and various animal oils and fats such as
tallow oil. The alkyl radicals may be derived synthetically
from sources such as alpha olefins.
Representative examples of useful branched,
saturated alkyl radicals include 12-methylstearyl; and
12-ethylstearyl. Representative examples of useful
branched, unsaturated radicals include 12-methyloleyl and
12-ethyloleyl. Representative examples of unbranched
saturated radicals include lauryl, stearyl; tridecyl;
myristal (tetradecyl); pentadecyl; hexadecyl; hydrogenated
tallow and docosonyl. Representative examples of un-
branched, unsaturated and unsubstituted long chain alkyl
radicals include oleyl, linoleyl; linolenyl, soya and
tallow.
R2, R3, R4
R?, R3, and R4 are individually selected from
the group consisting of hydrogen; a hydroxyalkyl group
having 2 to 6 carbon atoms; an alkyl group containing 1 to
22 carbon atoms; an aryl group an aralkyl group containing
1 to 22 carbon atoms in the alkyl chain of the aralkyl
group, and mixtures the~eof.
Preferably, R2 is selected from a group consist-
ing of a ~,y -unsaturated alkyl group having less than 7
aliphatic carbon atoms , a hydroxyalkyl group having 2 to 6
carbon atoms, and a aralkyl group containing 1 to 22 carbon
atoms in the alkyl chain of the aralkyl group and mixtures
thereof. Preferably R3 and R4 are individually selected
from a group consisting of a ~,y -unsaturated alkyl group, a
hydroxyalkyl group having 2 to 6 carbon atoms, an alkyl
group having 1 to 22 carbon atoms, an aralkyl group which
- 35 includes benzyl and substituted benzyl moieties including
fused ring moieties having linear or branched chains of 1 to
22 carbon atoms in the alkyl portion of the aralkyl group
and mixtures thereof.
Th,e hydroxyalkyl group may be selected from a
hydroxyl substituted aliphatic radical having from 2 to 6
33
--7--
aliphatic carbons wherein the hydroxyl is not substituted at
the carbon adjacent to the positive charged atom. The alkyl
group may be substituted with an aromatic ring. Representa-
tive examples include 2-hydroxyethyl; 3 hydroxypropyl;
4-hydroxypentyl; 6-hydroxyhexyl; 2-hydroxypropyl; 2-
hydroxybutyl; 2-hydroxypentyl; 2-hydroxyhexyl; 2-hydroxy-
cyclohexyl; 3-hydroxycyclohexyl; 4-hydroxycyclohexyl;
2-hydroxycyclopentyl; 3-hydroxycyclopentyl; 2-methyl-2-
hydroxypropyl; 3-methyl-2-hydroxybutyl; and 5-hydroxy-2-
pentenyl.
The alkyl group containing 1 to 22 carbon atoms
may be linear or branched, cyclic or acyclic, substituted
or unsubstituted. Representative examples of useful alkyl
groups include methyl; ethyl; propyl; 2-propyl; iso-butyl;
cyclopentyl; and cyclohexyl.
The alkyl radicals may be derived from sources
similar to the long chain alkyl radical, R1, above.
~he preferred ~,y -unsaturated alkyl group may
be cyclic or acyclic, unsubstituted or substituted.
unsaturated alkyl radicals preferably contain less than 7
aliphatic carbon atoms. Aliphatic radicals substituted on
the ~,Y - unsaturated group preferably containg less than
4 carbon atoms. The~ , r -unsaturated alkyl radical may be
substituted with an aromatic ring that is conjugated
with the unsaturation of the ~,y moietyO The~ ,y -
radical may also be substituted both with aliphatic
radicals and aromatic rings.
Representative examples of cyclic~ unsaturated
alkyl groups include 2-cyclohexenyl and 2-cyclopentenyl.
Representative examples of acyclic ~,~ - unsaturated alkyl
groups containing 6 or less carbon atoms include propargyl;
2-propenyl; 2-butenyl; 2-pentenyl; 2-hexenyl; 3-methyl-2-bu-
35 tenyl; 3-methyl-2-pentenyl; 2,3-dimethyl-2-butenyl; 1,1-di-
methyl-2-propenyl; 1,2-dimethyl-2-propenyl; 2,4-pentadienyl;
and 2,4-hexadienyl. Representative examples of acyclic-
aromatic substituted compounds include 3-phenyl-2-propenyl;
2-phenyl-2-propenyl; and 3-(4-methoxy phenyl)-2-propenyl.
Representative examples of aromatic and aliphatic sub-
- -8~ 6~ 0 33
stituted materials include 3-phenyl-2-cyclohexenyl;
3-phenyl-2-cyclopentenyl; alkyl group may be substituted
with an aromatic ring.
Examples of aryl groups would include phenyl
such as in N-alkyl and N,N-dialkyl anilines, wherein the
alkyl groups contain between 1 to 22 carbon atoms; ortho-,
meta- and para-nitrophenyl, ortho-, meta- and para-alkyl phenyl,
wherein the alkyl group contains between 1 and 22 carbon
atoms, ~-, 3-, and 4- halophenyl wherein the halo group is
defined as chloro, bromo, or iodo, and 2-, 3-, and 4-
carboxyphenyl and esters thereof, where the alcohol of the
ester is derived from an alkyl alcohol, wherein the alkyl
group contains between 1 and 22 carbon atoms, aryl such as a
phenol, or aralkyl such as benzyl alcohols; fused ring aryl
moieties such as naphthalene, anthracene, and phenanthrene.
Representative examples of an aralkyl group,
include benzyl and those materials derived from compounds
such as benzyl halides, benzhydryl halides, trityl halides,
1-halo-1-phenylalkanes wherein the alkyl chain has from
1 to 22 carbon atoms such as 1-halo-1-phenylethane; 1-halo-1-
phenylpropane; and 1-halo-1-phenyloctadecane substituted
benzyl moieties such as would be derived from ortho-, meta-
and para-chlorobenzyl halides, para-methoxybenzyl halides;
ortho-, meta- and para-nitrilobenzyl halides, and ortho-,
meta- and para-alkylbenzyl halides wherein the alkyl chain
contains from 1 to 22 carbon atoms; and fused ring benzyl-
type moieties such as would be derived from 2-halomethyl-
naphthalene, 9-halomethylanthracene and 9-halomethyl-
phenanthrene, wherein the halo group would be defined as
chloro~, bromo-, iodo-, or any other such group which serves
as a leaving group in the nucleophilic attack of the benzyl
type moiety such that the nucleophile replaces the leaving
group on the benzyl type moiety.
A compound is formed of the above described
organic cation and an anionic radical which is selected from
the group consisting of chloride, bromide, iodide, nitrite,
hydroxide, acetate, methyl sulfate and mixture thereof.
Preferably the anion is selected from the group consisting
-9~ 33
of chloride and bromide, and mixtures thereof, and is more
preferably chloride, although other anions such as iodide,
acetate, hydroxide, nitrite, etc., may be present in ~he
organic cationic compound to neutralize the cation.
Organic cationic salts may be prepared by methods
as disclosed in U.S. 2,355,356, 2,775,617 and 3,136,819.
The organic anions useful in this invention
should be capable of reacting with an organic cation and
form intercalations with a smectite-type clay as an organic
cation-organic anion complex. The molecular weight (gram
molecular weight) of the organic anion is preferably 3,000
or less, and most preferably 1,000 or less and contains at
least one acidic moiety per molecule as disclosed herein.
The organic anion is preferably derived ~rom an organic acid
having a pKA less than about 11Ø As indicated, the
source acid must contain at least one ionizable hydrogen
having the preferred pKA in order to allow the formation
of the organic cation-organic anion complex and subse~uent
intercalation reaction to occur.
Also useable is any compound which will provide
the desired organic anion or hydrolysis. Representative
compounds include:
1) acid anhydrides includin~ acetic anhydride,
maleic anhydride, succinic anhydride and phthalic anhydride;
2) acid halides including acetyl chloride octanoyl
chloride, lauroyl chloride, lauroyl bromide and benzoyl
bromide:
3) 1,1,1-trihalides including 1,1,1-trichloroethane
and 1,1,1-tribromooctane; and
4) orthoesters inlcuding ethyl orthoformate
and ethyl orthostearate.
The organic anions may be in the acid or salt
form. Salts may be selected from alkali metal salts,
alkaline earth salts, ammonia, and organic amines.
Representative salts include: hydrogen, lithium, sodium,
potassium, rnagnesium, calcium, barium, ammonium and organic
amines such as ethanolamine, diethanolamine, triethanolamine,
methyl diethanolamine, butyl diethanolamine, diethyl amine,
. ,
1333
- 1 O-
dimethyl amine, triethyl amine, dibutyl amine, and mixtures
thereof. The preferred alkali metal salt is sodium.
Suitable acidic functional organic compounds
include:
1) Carboxylic acids including:
(a) benzenecarboxylic acids such as benzoic
acid, ortho-, meta- and para-phthalic acid, 1,2,3-benzene
tricarboxylic acid; 1,2,4-benzenetricarboxylic acid;
1,3,5-benzenetricarboxylic acia; 1,2,~,5-bezene tetra-
carboxylic acid; 1,2,3,4,5,6-benzènehexacarboxylic acid
(mellitic acid);
(b) alkyl carboxylic acids having the
formula H-(CH2)n - COOH, wherein n is a number from
O to 20, such compounds include acetic acid; propionic
acid; butanoic acid; pentanoic acid; hexanoic acid;
heptanoic acid; octanoic acid; nonanoic acid; decanoic
acid; undecanoic acid; lauric acid; tridecanoic acid;
tetradecanoic acid; pentadecanoic acid; hexadecanoic acid;
heptadecanoic acid octadecanoic acid (stearic acid);
nonadecanoic acid; and eicosonic acid.
(c) alkyl dicarboxylic acids having the
formula HOOC-(CH~)n-COOH, wherein n ranges from 0 to 8,
such as oxalic acid; malonic acid; succinic acid; glutaric
acid; adipic acid; pimelic acid; suberic acid; azelaic acid;
and sebacic acid;
(d) hydroxyalkyl carboxylic acids such
as citric acid; tartaric acids; malic acid; mandelic acid;
and 12-hydroxystearic acid;
(e) unsaturated alkyl carboxylic acids
such as maleic acid; fumaric acid; and cinnamic acid;
(f) fused ring aromatic carboxylic acids
such as napthalenic acid; and anthracene carboxylic acid;
(g) cycloaliphatic acids such as cyclohexane
carboxylic acid; cyclopentane carboxylic acid; furan
corboxylic acids.
2) Organic sulfur acids including:
(a) sulfonic acids including~
(1) benzenesulfonic acids such as
~.3L66~c~33
benzenesulfonic acid; phenolsulfonic acid; dodecylbenzene-
sulfonic acid; benzenedisulfonic acid, benzenetrisulfonic
acids; para-toluenesulfonic acid; and
(2) alkyl sulfonic acids such as
methane sulfonic acid; ethane sulfonic acid; butane
sulfonic acid; butane disulfonic acid; sulfosuccinate alkyl
esters such as dioctyl succinyl sulfonic acid; and alkyl
polyethoxy-succinyl sulfonic acid; and
(b) alkyl sulfates such as the lauryl
half ester of sulfuric acid ancl the octadecyl half ester
of sulfuric acid.
3) Organophosphorus acids including;
(a) phosphonic acids having the formula:
O
Il
R-P(OH)2
wherein R is an aryl group or alkyl having 1 to 22 carbon
atoms;
(b) phosphinic acids having the formula:
O
ll
R2POH
wherein R is an aryl group or alkyl group having 1 to
22 carbon atoms, such as dicyclohexyl phosphinic acid:
dibutyl phosphinic acid; and dilauryl phosphinic acid;
(c) thiophosphinic acids having the formula:
S
"
R2PSH
wherein R is an aryl group or alkyl group having 1 to 22
carbon atoms such as di-iso-butyl dithiophosphinic acid;
dibutyl dithiophosphinic acid; dioctadecyl dithiophosphiric
acid;
(d) phosphites, that is diesters of
phosphorous acid having the formula: HO-P(OR)2; wherein R
is an alkyl group having 1 to 22 carbon atoms such as
dioctadecylphosphite;
(e) phosphates, that is diesters of phosphoric
"
-12- ~G~V33
acid having the formula:
o
..
Ho-p - (oR)2
wherein R is an alkyl group having 1 to 22 carbon atoms,
such as dioctadecyl phosphate.
4) Phenols such as phenol; hydroquinone;
t-butylcatechol; p-methoxyphenol; and naphthols.
5) Thioacids having the formulae:
S
ll
R-C-OH,
O
..
R-C-SH
and
S
"
R-C-SH
wherein R is an aryl group or alkyl group having 1 to 22
carbon atoms, such as thiosalicylic acid; thioben~oic acid;
thioacetic acid; thiolauric acidi and thiostearic acid.
6) Amino acids such as the naturally occurring~
amino acids and derivatives thereof such as 6 aminohexanoic
acid; 12-aminododecanoic acid, N-phenylgylcine; and 3-
aminocrotonic acid.
7) Polymeric acids prepared from acidic monomers
wherein the acidic function remains in the polymer chain
such as low molecular weight acrylic acid polymers and
copolymers; styrene maleic anhydride copolymers.
8) Miscellaneous acids and acid salts such
as ferrocyanide; ferricyanide; sodium tetraphenylborate;
phosphotungstic acid; phosphosilicic acid, or any other such
anion which will form a tight ion pair with an organic
cation, i.e., any such anion which forms a water insoluble
precipitate with an organic cation.
For convenience of handling it is preferred that
the total orclanic content of the organophilic clay reaction
,.,
~16~33
-13~
products of this invention should be less than about 50% by
weight of the organoclay. While higher amounts are usable
the reaction product is difficult to filter, dry and grind.
A sufficient amount of organic cation is employed
to satisfy the cation exchange capacity of the clay and the
cationic activity of the organic anion. Additional amounts
of cation above the sum of the exchange capacity of the clay
and anion are optional. For example, smectite-type clays
require at least 90 milliequivalents of organic cation to
satisfy at least a portion of the total organic cation
re~uirement. Use of amounts from 80 to 200 M.E., and
preferably 100 to 160 M.E. are acceptable. At lower milli-
equivalents rations, an incomplete reaction will occurresulting in an ineffective gellant.
The amount of organic anion added to the clay
should be sufficient to impart to the organophilic clay the
enhanced dispersion characteristic desired. This amount is
defined as the milliequivalent ratio which is the number of
milliequivalents (M.E.) of the organic anion in the organoclay
per 100 grams of clay, 100% active clay basis. The anion
milliequivalent ratio should preferably range from 5~to 100
and preferably 10 to 50.
The organic anion is preferably added to the
reactants in the desired milliequivalent ratio as a solid or
solution in water under agitation to effect a macroscopically
homogenous mixture.
Smectite-type clays occur naturally or are pre-
pared synthetically. Suitable clays include montmorillonite,
bentonite, beidellite, hectorite, saponite, and stevensite.
In particular smectite-type clays should have a cation
exchange capacity of at least 75 milliequivalents per 100
grams of clay. Particularly desirable types of clay are the
naturally-occurring Wyoming varieties of bentonite and
hectorite, a swelling magnesium-lithium silicate clay.
Suitable synthetic clays may be synthesized by conventional
means including pneumatolitic and hydrothermal methods.
The clays, especially the bentonite type clays,
are preferably converted to the sodium form if they are not
~ ~6~ 33
-14-
already in this form. This can conveniently be done by
preparing an aqueous clay slurry and passing the slurry
through a bed of cation exchange resin in the sodium form.
Alternatively, the clay can be mixed with water and a
soluble sodium compound such as sodium carbonate and sodium
hydroxide followed by shearing the mixture with a pugmill or
extruder.
The cation exchange capacity of the smectite-type
clays can be determined by the ammonium acetate method.
The clay is preferably dispersed in water at
a concentration from about 1 to 80% and preferably about 2%
to 20%, and more preferably about 2~ to 7~. The slurry is
agitated prior to reaction.
The organic cationic compounds of the invention
were prepared by standard prior art methods starting with an
amine having the desired number of long chain alkyl groups
bonded to the nitrogen atom. This long chain alkyl amine
was then reacted by reductive alXylation with an aldehyde
and/or by nucleophilic displacement of an alkyl halide to
form the desired quaternary ammonium compound.
The fluid of this invention may contain the
aqueous phase includes aqueous solutions of inorganic salts
such as sodium chloride and calcium chloride. While addition
of these salts is optional, such salts increase the osmotic
pressure of the water phase of the formations containing
hydratable clays.
The a concentration of water in the fluid is deter-
mined by factors such as fluid weight requirements, flow
properties desired, bottom-hole temperatures and the
operational requirements of drilling, coring, or comple-
tion. In general, it is preferable to employ a volume
percent of water ranging from about 2 to about 50%. This
range renders the oil-base fluid fire-resistant upon
exposure to temperatures that would ignite the oil. In
addition, the fluid has excellent tolerance to wa~er contami-
nation; and fluid flow properties can be controlled at
values comparable to those of water-based fluids.
-15- ~L6~33
Conventional emulsifiers should be employed for
the water-in-oil phase and may be employed for the
non-aqueous fluid. The amount of emulsifier employed is
primarily dependent upon the amount of water present and the
extent of emulsification desired. Generally from 2 to 30
lbs. per barrel and preferably from 5 to 20 lbs. per barrel
have been found satisfactory to achieve the necessary gel
strengths and filtration control.
The compositions may optionally contain convention-
al weighting agents such as barite for controlling fluid
density between 7.5 and 22 lb/gal as well as fluid loss
control agents.
The smectite-type clays used in the Examples
were hectorite and Wyoming bentonite. The clay was slurried
in water and centrifuged to remove essentially all of the
non-clay impurities which may amount to 10% to about 50% of
the starting clay composition. The Wyoming bentonite clay
slurry was passed through a bed of cation exchange resin to
convert it to the sodium form.
Examples 1 to 4 demonstrate the preparation
of various organic cationic compounds which compounds may
be used as reactants with an organoclay to form the organo-
philic clay reaction products of this invention.
The organic cationic compounds exemplified arerepresentative of the cations of the invention and are not
intended to be inclusive of only operative compounds.
The following examples are given to illustrate the
invention, but are not deemed to be limiting thereof. All
percentages given are based upon weight unless otherwise
indicated. Plastic viscosity, yield point, and ten second
gels were measured by the procedure described in API RP13B,
American Petroleum Institutes Standard Procedure ~or Testing
Fluids, 6th Ed., April 1~76.
Example 1
Allyl methyl di(hydrogenated-tallow) ammonium
chloride (AM2HT).
824.7 g methyl di(hydrogenated-tallow) amine,
350 ml isopropyl alcohol, 250 g NaHCO3, 191.3 gmO allyl
, . .
-16- ~6~33
chloride, and 10 gm. allyl bromide (as a catalyst) were
mixed in a 4-liter reaction vessel equipped with a condenser.
The mixture was heated and allowed to reflux. A sample was
removed, filtered, and titrated with HCl and NaOH. The
reaction was considered complete as there was 0.0% amine HCl
and 1.8% amine. The final analysis of the A~2HT showed an
effective gram molecular weight of 831.17.
Example 2
A 3% clay slurry (sodium form of Wyoming bentonite)
was heated to 60C with stirring.~ 4.8637g (M.E. Ratio -
22.5) of an organic anionic compound, sodium benzoate (M.W.
144.11) was dissolved in water. The organic anion solution
was added to the clay slurry and reacted for 10 ~inutes at
60C. 136.89 g (M.E. ratio - 122.5) ethanol methyl di
(hydro~enated-tallow) ammonium chloride [EM2HT] (M.W.
745) (Armak Co., Division of Akzona Corp.) is dissolved in a
50% 2-propanol aqueous solution. The cation sGlution was
added and stirred for 45 minutes at 60C. The organoclay
(EM2HT/benzoate/bentonite~ was collected on a vacuum filter.
The filter cake was washed with hot water and dried at 60C.
The dried organoclay was ground using a hammer mill to
reduce the particle size and then sieved through a U.S.
Standard 200 mesh screen.
Example 3
A 3% clay slurry (sodium form of Wyoming bentonite)
was heated to 60C. with stirring. 7.83g (M.E. Ratio
22.5) of an organic anionic compound, p-Phenolsulfonic acid
sodium salt (M.W. 232.19) was dissolved in water. The
organic anion solution was added to the clay slurry and
reacted for 10 minutes at 60C. 134.42g (M.E. ratio -
122.5) benzyl methyl di(hydrogenated-tallow) ammonium
chloride BM2HT was dissolved in a 50% 2-propanol aqueous
solution. The cation solution was added and stirred for 45
minutes at 60C. The organoclay (BM2HT/p-phenolsulfonate/
bentonite) was collected on a vacuum filter. The filter cake
was washed with hot water and dried at 60C. The dried orqano-
clay is ground usinq a hammer mill to reduce the particle size
and then sieved through a V.S. Standard 200 mesh screen.
-17 ~16~33
Example 4
A 3% clay slurry (sodium form of Wyoming bentonite)
was heated to 60C. with stirring. 5.40g (M.E. Ratio -
22.5) of an organic anionic compound, sodium salt of
salicylic acid (M.~. 160.11) was dissolved in water. The
organic anion solution was added to the clay slurry and
reacted for 10 minutes at 60C. 134.72g (M.E. ratio -
122.5) of AM2HT prepared in Example 1 is dissolved in a50% 2-propanol aqueous solution. The cation solution was
added and stirred for 45 minutes at 60C. The organoclay
(AM2HT/salicylate/bentonite) was collected on a ~7acuum filter.
The filter cake was washed with hot water and dried at 60C.
The dried organoclay was ground using a hammer mill to reduce
the particle size and then sieved through a U.S. Standard 200
mesh screen.
Examples 5-9
0.63 bbl of diesel oil, 8 pounds emulsifier
(Invermul, NL Industries, Inc.), 8 pounds filtration
control, amine lignite (Duratone HT, NL Industries, Inc.), 4
pounds lime, and 0.11 bbl. of water was stirred for 20
minutes.
22 pounds of calcium chloride~ 325 pounds of
barite (Baroid/NL Industriesl Inc.) and 5 pounds of of the
three bentonite clay thickeners prepared in Examples 2-4 in
addition to commercial products dimethyl di(hydrogenated-
tallow) ammonium chloride (2M2HT)/bentonite and benzyl
methyl di(hydrogenated-tallow) ammonium chloride (BM2HT)/
bentonite.
The mixed fluid was tested at 95~F. for standard
rheology data and the results are shown in Table 2~ None of
the Examples settled following stirring:
~6~C~33
--18--
(
Table 2
Yield 10 sec. 10 min.
Point Gel Gel
Example #/ 2 ~/ 2 / 2
No. Gellant Compound ; 100ft 100ft 100ft
S E~12HT/benzoate/ 16 8 12
bentonite
6 BM2HT/p-phenolsulfonate/ 24 14 16
bentonite
7 AM2HT/salicylate/ 18 10 14
bentonite
8 2M2HT/bentonite 30 16 19
9 BM2HT/bentonite 24 14 18
The unstirred batches of Examples 5-9 were rolled at
150F for 16 hours and no settling was noted in any ~xample.
The fluid was stirred for 25 minutes and tested at 88F for
standard rheology data as in Example 5. The results are
shown in Table 3 below. None of the Example settled following
Stirring
Table 3
Yield 10 sec. 10 min.
Point Gel Gel
Example ~/ #/ ~/ 2
No. 100ft2 100ft2 ldOft
14 7 1û
6 22 14 17
7 16 11 13
8 20 13 18
9 21 14 19
350 mlbatches of fluid consisting of 0.60 of
diesel oil, 8 pounds emulsifier (Invermul(~), NL
Industries, Inc.), 8 pounds amine lignite filtration
control (Duratone(~, NL Industries, Inc.), 5 pounds lime,
0.20 bbl of ll.O ppg calcium chloride, and 320 pounds of
35 barite (Baroid~, NL Industries, Inc.) were admixed,
stirred for 15 minutes in a Hamilton Beach mixer and
cooled to 28F in an ice bath. A 6 lb/bbl concentration
of gellants EM2HT/benzoate/bentonite, BM2HT/p-phenol-
sulfonate/bentonite and AM2HT/salicylate/bentonate
40 produced in Example 2-4 in
033
, g
over a 5 minute period at low shear with a Lightnin mixer.
The cold examples in a viscometer cup, were placed on a Fann
35 viscometer and stirred at 600 rpm while the temperature
rose to 70F. The batches;were then placed in a preheated
cup jackets set at 125F and allowed to heat to 110F. The
plastic viscosity, yield point and 10-sec gel were measured
at every 5F increment between 30 to 70F and at every 10F
increment between 70 to 110F. The results of the measure-
ments are presented in Figure 1.
Examples I0-14 at 115F were stirred for 15
minutes in a Hamilton Beach mixer and cooled to 80F and
tested as with Example 5. The results are presented in
Table 4 below.
Table 4
Yield 10 sec. 10 min.
Point Gel Gel
Example ~/ 2 ~/ 2 #/ 2
No. Gellant Compound 100ft100ft 100ft
E~2HT~benzoate/ 40 17 20
bentonite
11 BM2HT/p-phenolsulfonate/ 51 27 29
bentonite
12 A~;2HT/salicyllate/ 54 23 30
~5 bentonite
13 2i~2~T/bentonite 50 21 26
14 BM2HT/bentonite 50 23 28
Example 20-14
Batches of fluids consisting of 0.41 bbl of diesel
oil and 12 pounds of gellant clays prepared in Examples 2,
3, 4 and 5 in addition to 2i~2HT/bentonite amd BM2HT/Bentonite
which were prepared without anionic reactants were admixed
and stirred for five minutes in a Hamilton Beach mixer at
low speed. 0.41 bbl of diesel oil, 18 pounds asphalt
(Baroid~ sphalt, NL Industries, Inc.) and 0.275 pounds of
barite, (Baroid~ NL Industries, Inc.) were admixed with
the prepared batches above and stirred for 15 minutes in a
Hamilton Beach mixer.
350 ml samples of Examples 15 through l9 were
tested for rheological properties as in Example 5 at 93F.
~L~6~333
~20-
The results are presented in Table 5 below.
Table 5
Yield 10 sec. 10 min.
Point Gel Gel
Example #/ #/ #/
No. Gellant Compound 100ft2 100ft2 100ft2
__
EM~HT/benzoate/ 15 7 27
bentonite
16 BM2HT/p-phenolsulfonate/ 17 7 31
bentonite
17 AM2HT/salicylate/ 15 4 11
bentonite
18 2M2HT/bentonite 54 34 74
19 BM2HT/bentonite 25 11 40
350 ml samples of Example 15 through 19 were hot
rolled at 150F for 16 hours. After cooling the batches to
80F, settling of solids were checked prior to measurement
of rheological properties as in Example 5 at 93F. The
2n results are shown in Table 6 below.
Table 6
Yield 10 sec. 10 minO
Point Gel Gel
Example #/ 2 #/ 2 2
~o. Gellant_Compound 100ft100ft 100ft
EM2HT/sodium benzoate/37 10 40
bentonite
16 BM2HT/p-phenolsulfonate/ 37 13 55
bentonite
17 AM2HT/salicylate/ 52 17 78
bentonite
18 2M2HT/bentonite 91 55 100
19 BM2HT/bentonite 69 39 108
Mud cake and filtrates were stirred back into the
respective samples and the batches were aged for 16 hours at
350F.
Each batch was cooled to 80F and checked for
solids settling. The batches were stirred for 5 minutes and
tested as with Example 5. The results are shown in Table 7
below.
.~
2 ~ 13 33
(
Table 7
Yield 10 sec. 10 min.
Point Gel Gel
Example #/ #/ 2
No. Gellant Compound ~ lOOft2 100ft lOOft2
EM2HT/benzoate/ 68 10 34
bentonite
16 BM2HT/p-phenolsulfonate/70 14 51
bentonite
17 AM2HT/salicylate/ 62 15 30
bentonite
18 2M2HT/bentonite 120 45 82
13 BM2HT/bentonite 99 41 78
Examples 20 to 24
350 ml. batches of fluids consis~ing of 0.69 bbl
of diesel oil, 6 pounds emulsifier (EZ mul, ~L Industries,
Inc.), 0.17 bbl of water, 225 pounds of barite (Baroid~3NL
Industries, Inc.), 24 pounds of calcium chloride and 6
pounds of gellant clays EM2HT/benzoate/bentonite, Bl~l2HT/
p-phenolsulfonate/bentonite and AM2HT/salicylate/bentonite
prepared in Examples 2-4 respectively in addi~ion to 2M2HT/
bentonite and BIY2HT/ bentonite described in Example 5 were
admixed and stirred for 20 minutes in a Hamilton Beach mixer.
350 ml. batches of Examples 20 through 24 were
tested at 88F for rheolo~ical properties as in Example 5.
The results are presented in Table 8 below.
Table 8
~ield 10 sec. 10 min.
Point Gel Gel
Example #/ 2 ~/ 2 ~/ 2
No. Gellant Compound 100ft100ft100ft
-
EM2HT/benzoate/ 9 4 6
bentonite
21 ~Y2HT/p-phenolsulfonate/ 8 4 6
bentonite
22 AM2HT/salicylate/ 9 4 5
bentonite
23 2M2HT/bentonite 9 5 6
24 BM2HT/bentonite 8 4 5
. , ~
-22- ~ 033
350 ml sample of Example 20 through 24 were hot
rolled at 150F for 16 hours. After cooling the batches to
80F, settling of solids was checked prior to measurement
of rheological properties as in Example 5 at 84F. The
results are shown in Table 9 below.
Table 9
Yield 10 sec.10 min.
Point Gel Gel
Example #/ 2 #/ 2 #/ 2
No. 100ft 100ft 100ft
9 5 5
21 9 5 7
5 22 10 5 8
23 15 8 14
24 ~ 4 5
Mud cake and filtrate were stirred back into the
respective samples and the batches were aged for 16 hours at
3soF.
Each batch was cooled to 80F and checked for
solids settling. The batches were stirred for 5 minutes and
tested as with Example 5~ HT-HP filtrates were conducted on
each batch at 350 F. The results are shown in Table 10
below.
Table 10
Yield 10 sec. 10 min.
Point ~el Gel
Example #/ 2 #/ 2 #/ 2
No. 100ft 100ft 100ft
3020 10
21 6 4 5
22 9 4
23 12 5
24 8 4 5
Example 25-29
350 ml. batches of a fluid consisting of 0.63 bbl
of diesel oil, 8 pounds emulsifier (Invermul, NL Industries,
Inc.), 0.11 bbl of water, 325 pounds of barite (Baroid, NL
Industries, Inc.), 8 pounds filtration aid (Duratone - NL
Industries, Xnc.), 22 pounds of calcium chloride, ~ pounds
-
- -23- ~6~33
lime and 9 pounds of gellant clays, EM2HT/benzoate/bentonite,
BM2HT/p-phenolsulfonate/ bentonite, and AM2HT/salicylate/
bentonite prepared in Examples 2-4 respectively, commercial`
clays 2M2HT/bentonite, BM2HT/ bentonite described in Example
5 above and an additional commercial clay.
350 ml samples of Examples 25 through 29 were
tested at 92F for rheological properties as in Example 5.
The results are presented in Table 11.
Table 11
Yield 10 sec. 10 min.
Point Gel Gel
Example #/ 2 #/ 2 #/ 2
No. _ellant Composition 100ft100ft 100ft
1525 EM2HT/sodium benzonate 40 14 18
bentonite
26 BM2HT/p-phenol sulfonic acid 55 28 33
bentonite
27 AM2HT/salicylic acid 43 18 20
bentonite
28 2M2HT/bentonite 60 22 33
29 BM2HT/bentonite 51 24 28
The batches were aged for 16 hours at 300F,
cooled to 80F, checked for solids settling. The batches
were stirred for 10 minutes and tested as with Example 5 at
90F. The results are shown in Table 12 below.
Table 12
Yield 10 sec. 10 min.
Point Gel Gel
Example#/ 2 #/ 2 #/ 2
30No. 100ft 100ft 100ft
32 18 23
26 29 23 28
27 27 20 26
28 34 18 26
3529 26 24 29
~.3L~136~33
-24-
It will be obvious to one skilled in the art that
the invention may be varied in many ways. Such variations
are not to be regarded as a departure from the spirit and
scope of the invention and all such modifications are
intended to be included within the scope of the following
claims.
