Note: Descriptions are shown in the official language in which they were submitted.
~6~03;~
OIL BASE FLUIDS CONTAININIG 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 Ieast 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.,
; 15 Inc.), particularly Chapter lQ, Clay-Mineral-Organic
Reactions; pp. 356-368 - Ionic Reactions, Smectite; and
pp. 392-401 - Organophilic Clay-Mineral Complexes.
Maximum gelling (thickening) efficiency fro~ 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'H~lloran
2,677,661; McCarthy et al. 2,704,276; Stratton 2,833,720;~
Stratton 2,879,229; and Stansfield et al. 3,294,683. The
use of such dispersion aids was found unnecessary when us-
ing particular organophilic clays derived from substituted
. ~ '~
i
-~6(~)3Z
--2--
quaternary ammonium compounds as disclosed in Finlayson et
al. 4,105,S78 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 comprises
an organophilic gellant comprising the reaction product of
an oil phase, and from about 1 to about 50 lbs. per barrel
of an organic cationic compound and a smectite-type clay
having a cation exchange capacity of at least 75 milli-
equivalents per 100 grams of said clay, the organic cationic
- compound containing:
(a) a first member selected rom the group
consisting of a ~,~ -unsaturated alkyl group, having less
than 7 aliphatic carbon atoms and a hydroxyalkyl group having
2 to 6 carbon atoms and mixtures thereof,
(b) a second group comprising a long chain alkyl
group having 8 to 60 carbon atoms and
(c) a third and fourth member selected from a
group consistin~ of a~ unsaturated alkyl group having
less than 7 aliphatic carbon atoms , a hydroxyalkyl group
having 2 to 6 carbon atoms, an aralkyl group, and an alkyl
group having 1 to 22 carbon atoms and mixtures thereof; and
wherein the amount of said organic cationic compound is from
90 to 140 milliequivalents per 100 grams of said clay, 100%
active clay basis.
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 an organophilic clay gellant. Preferably, the
fluid is non-aqueous.
A suitable oil phase of this invention ma~ be
crude petroleum and fractions thereof, including but not
limited to diesel oil, kerosene, fuel oil, light lubricating
oil fractions, and heavy naphtha having a boiling range
,,
~L~L6~t3;~
--3--
between about 300 to 600F. The preferred material is
diesel oil.
The amount of the organophilic clay employed is
that amount which is effective in obtaining the necessary
degree of gellation (thickening) of the oil-base fluid for
the intended application~ that is, drilling fluid or packer
fluid. The minimwn concentration of organophilic clay
needed to gel a particular fluid is dependent upon factors
such as the type of organophilic clay used, the characteris-
tics of the oil phase and emulsif~ied water phase if any, and
the maximum temperature to which the fluid is to be raised.
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
barrel) 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 packer fluids. ~t 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 down-hole 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. The
optional emulsifiers, weighting agents, and fluid loss
control materials may be added at any time. It is only
necessary to obtain a stable the fluid prior to usage of
the fluid. Once prepared, the packer fluid is transferred,
such as by pumping, into a well bore or to tubing canulas,
at least one portion of which is to be filled.
_4_ ~LG~3Z
The oil-base drilling fluid can be prepared and
used either before drillinq 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 employing a low shear mixing
force. Greater mixing force may be employed even though not
necessary. Once prepared, the drilling fluid is trans-
ferred, such as by pumping, into a well bore andcirculated 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, quaternary ammonium
compound and water together, preferably at a temperature
within the range from 20C to 100C, and most preferably
from 35C to 77C for a period of time sufficient for the
organic compound to react with the clay particles, followed
by filtering, washing, drying and grinding. The ~uaternary
compound is added in the desired milliequivalent ratio,
preferably dispersed in isopropanol or water. In using the
organophilic clays in emulsions, the drying and grinding
steps may be eliminated. When the clay, quaternary ammonium
compound and water are admixed in such concentrations
that a slurry is not formed, filtration and washing steps
may be eliminated.
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 or~anic cationic
compound must 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 quarternary ammonium salts, phosphonium salts,
and mixtures thereof, as well as equivalent salts. The
organic cation preferably contains at least one member
selected from each of two groups, the first group consisting
of a ~, y-unsaturated alkyl group having less than 7 aliphatic
carbon atoms, a hydroxyalkyl group having 2 to 6 carbon
~5~ ~6~32
atoms and mixtures thereof and the second group consisting
of a long chain alkyl group.
A representative formula of the organic cation
is ~
R4 X R2
wherein Rl is selected from the 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
mixtures thereof; R2 is a long chain alkyl group having 8
to 60 carbon atoms; R3 and R4 are selected from a 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 ; and X is
phosphorous or nitrogen.
Rl
The ~,y -unsaturated alkyl group may be select~ed
from a wide range of materials. These compounds may be
cyclic or acyclic, unsubstituted or substituted. ~,r-
unsaturated alkyl radicals should contain less than 7aliphatic carbon atoms. The aliphatic radical of the ~,y
-unsaturated alkyl radicals preferably contains less than 4
aliphatic carbons. The ~,y -unsaturated alkyl radical may be
substituted with an aromatic ring that is con}ugated with
the unsaturation of the ~, y moiety. The ~,y - radical may
also be substituted with both aliphatic radicals and
aromatic rings.
Representative examples of cyclic ~,y -unsaturated
alkyl groups include 2-cyclohexenyl and 2-cyclopentenyl.
Representative examples of acyclic ~,y - unsaturated alkyl
3Z
--6--
groups containing 6 or less carbon atoms include propargyl;
2-propenyl; 2-butenyl; 2-pentenyl; 2-hexenyl; 3-methyl-2-bu-
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-methoxyphenyl)-2-propenyl.
Representative examples of arornatic and aliphatic substituted
materials include 3-phenyl-2-cyclohexenyl; 3-phenyl-2-
cyclopentenyl. The alkyl group may be substituted with an
aromatic rin~.
The hydroxyalkyl group may be selected from a
hydroxyl substituted aliphatic radical having from 2 to 6
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.
R2
The long chain alkyl radicals may be branched orunbranched, saturated or unsaturated, substituted or unsub-
stituted and should have from 8 to 60 carbon atoms in thestraight chain portion of the radical.
The long chain alkyl radicals may be derived from
naturally occurring oils including various vegetable oils~
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 alpha olefins.
Representative examples of useful branched,
saturated alkyl radicals include 12-methylstearyl; and
12-ethylstearyl. Representative examples of useful branched,
~6~Q3~
--7--
unsaturated radicals include 12-methyloleyl and 12-ethyloleyl.
Representative examples of unbranched saturated radicals
include lauryl; stearyl; tridecyl; myristal (tetradecyl);
pentadecyl; hexadecyl; hydrogenated tallow; docosonyl.
Representative exar,lples of unbranched, unsaturated and
unsubstituted long cnain alkyl radicals include oleyl,
linoleyl; linolenyl, soya and tallow.
R3 and R4
R3 and R~ are individually selected from a
group consisting of (a) a ~, ~-unsaturated alkyl group
having less than 7 aliphatic carbon atoms, described above,
(b) a hydroxyalkyl group having 2 to 6 carbon atoms,
described above; (c) a cyclic or acyclic alkyl group having
1 to 22 carbon atoms, and (d) an aralkyl group which 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.
The long chain alkyl group of R3 and R4 may be
linear or branched, cyclic or acyclic, substituted or
unsubstituted, containing 1 to 22 carbon atoms. Representa-
tive examples of useful alkyl groups include methyl; ethyl;
- 25 propyl; 2-propyl; iso-butyl; cyclopentyl; and cyclohexyl.
The alkyl radicals may be derived from sources
similar to the long chain alkyl radical of R2 above.
Representative examples of an aralkyl group
would 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-phenyl propane; 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
.
3~
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 quaternary compound is formed of the above
described organic cationic compound and an anionic radical
which selected from the group consisting of chloride,
bromide, nitrite, hydroxide, acetate and mixtures thereof.
Preferably the anion is selected from the group consisting
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 the
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.
For convenience of handling it is preferred that
the total organic content of the organophilic clay reaction
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.
The amount of organic cation added to the clay
for purposes of this invention must be sufficient to impart
to the clay the enhanced dispersion characteristic desired.
This amount is defined as the millequivalent ratio which is
the number of milliequivalents (M.E.) of the organic cation
in the organoclay per 100 grams of clay, 100% active clay
basis. The organophilic clays of this invention must have
a milliequivalent ratio from 90 to 140 and preferably 100
to 130. At lower milliequivalent ratios the organophilic
clays produced are not effective gellants. At higher
milliequivalent ratios the organophilic clays are poor
gellants. However, the pre~erred milliequivalent ratio
within the range from 90 to 140 will vary depending
on the characteristics of the organic system to be gelled by
the organophilic clay.
The manner in which the organic cation function~
in the organophilic clay reaction products of this invention
-9- ~ V3Z
( is not fully known. The unique properties associated with
the compositions of this invention are believed however to
relate to the electron withdrawing and donating portions of
the cation and particulariy to the essential presence of
at least one long chain alkyl group coupled with a ~,
-unsaturated alkyl group or a nydroxyalkyl group.
When bonded to a positivly charged atom the long chain a]jkyl
group appears to function as an electron donor which aids
in delocalizing the positive charge. More importantly
however it enables the clay platel~ets to be separated
sufficiently to allow further separation under moderate
shear conditions. In contrast, the ~, y-unsaturated alkyl
group appears to create a delocalization of the positive
charge which may result from a resonance or inductive
effect occurring with the unsaturated alkyl group. This
effect does not occur tQ any significant extent with other
prior art saturated alkyl groups. The enhanced function of
the short chain hydroxyalkyl group appears to be related
to the internal covalent bonded polar activating moiety t
namely the hydroxyl group when not adjacent the positive
charged atom. This effect is negated when the hydroxyl
moiety is located on a carbon atom adjacent to the positive
~5 charged atom or on an alkyl gro~n greater than 6 carbon
atoms.
Suitable smectite-type clays occur naturally or
may be prepared synthetically. Such clays include mont-
morillonite, bentonite, beidellite, hectorite, saponite,
and stevensite. In particular smectite-type clays should
have a cation exchange capacity of at least 75 milli-
equivalents per 100 grams of clay. Particularly desirable
types of clay are the naturally-occurring Wyoming varieties
of bentonite and hectorite, a magnesium-lithium silicate
clay. Suitable clays may also be synthesized by conven-
tional means including pneumatolitic and hydrothermal
methods.
The clays, especially the bentonite type clays,
are preferably converted to the sodium form if they are no~
~0 already in this form. This can conveniently be done by
- 1 O-
preparinq 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 determinèd by the ammonium acetate method.
The clay is preferably dispersed in water in
a weight concentration ranging from about 1 to about 80% and
preferably from about 2~ to about 20%, and more preferably
from about 2% to about 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 alkylation with an aldehyde
or by nucleophilic displacement of an alkyl halide to
form the desired quaternary ammonium compound.
The fluid of this invention may contain an aqueous
phase which includes aqueous solutions of inorganic salts
such as sodium chloride and calcium chloride. While addi-
tion of these salts is optional, such salts increase the
osmotic pressure of the water phase to stabilize formations
containing hydratable clays.
The concentration of water in the fluid is deter-
mined by factors such as fluid weight requirements, flowproperties desired, bottom-hole temperatures and the opera-
tional requirements of drilling, coring, or completion. In
general, it has been found preferably to employ a volume
percent of water ranging from about 2 to about 50%. This
range renders the oil-base fluid fire~resistant upon expo-
sure to temperatures that would ignite it. In addition, the
fluid has excellent tolerance to water contamination; and
fluid flow properties can be controlled at values comparable
to those of water-based fluids.
In using an aqueous phase in the fluid, conven-
~6(~3Z
tional emulsifiers should be employed for the water-in-
oil phase. In the non-agueous fluid, emulsifiers may also
be used. 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 1 to 15 lbs. per barrel have been
found satisfactory to achieve the emulsion stability.
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 Wyomin~ bentonite. The clay was slurried
n water and centrifuged to remove essentially all of the
non-clay impurities which may amount to 10% to a~out 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.
The organic cationic compounds exemplified are
representative of the cations of the invention and are not
intended to be inclusive of the 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 Procedure0 for Testing Fluids, 6th Ed., April 1976.
Example 1
Allyl methyl di(hydrogenated-tallow) ammonium
chloride (abbreviated AM2HT).
824.7 g methyl di(hydrogenated-tallow) amine, 350
ml isopropyl alcohol, 250 g NaHCO3, 191.3 g are placed
allyl chloricle, and 10 g allyl bromide (as a catalyst) in
a 4-liter reaction vessel equipped with a condenser, the
mixture is heated and allowed to reflux. A sample was
removed, filtered, and titrated with HCl and NaOH. The
reaction was considered complete at 0.0~ amine HCl and 1.8%
3Z
-12-
!
amine. The final analysis showed an effective gram molecular
weiqht of 831.17.
Examples 2-4
A 3~ clay slurry, the sodium form of Wyoming
bentonite for Examples 2 and 3 and hectorite for Example 4,
was heated to 60C with stirring. An isopropyl alochol
solution of organic cationic compound, ethanol methyl
di(hydrogenated tallow) ammonium chloride [E~fil2HT] - (Armak
Co. Division of Akzona Corp.) at 80% activity in Example 2
and AM2HT, prepared in Example 1, for Examples 3 and 4 was
added to the clay slurry and stirred for 20 minutes. The
orgânoclay was collected on a vacuum filter. The filter cake
was washed with 60C water and dried at 60C. The dried
oryanoclay was ground using a hammer mill to reduce the
particle size and sieved through a U.S. Standard 200 mesh
screen.
Examples 5-8
~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, 0.11 bbl. of water was stirred for 20 minutes.
22 pounds of calcium chloride, 325 pounds of barite
(Baroid, NL Industries, Inc.) and 5 pounds of the two bentonite
clay thickeners prepared in Examples 2 and 3 in addition to
two 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 95E. for standard
rheology data and the results are shown in Table 1~ None of
the Examples settled following stirring:
Table 1
Yield 10 sec. 10 min.
Point Gel Gel
Example Gellant #/ 2 #/ #/
No. Compound 100ft 100ft2 100ft2
EM2H'r/bentonite 18 9 13
6 AM2~3T/bentonite 20 11 14
7 2M2HT/bentonite 30 16 19
40 8 BM2~3T/bentonite 24 14 18
~L~L6~6~32
-13-
The unstirred batches of Examples 5-8 were rolled at
150F for 16 hours and no settlinq was noted in any Example.
The batches were tested at 80F for standard rheology data
as in Example 5. The results are shown in Table 2 below.
None of the Examples settled.
Table 2
Yield 10 sec. 10 min.
Point Gel Gel
Example #/ ~/ #/
No. 100ft2 lOOft2 100ft
19 5 14
6 17 12 15
7 20 13 18
15 8 21 14 19
Examples 9-13
350 ml. batches of of fluids consistin~ of 0.60
bbl o~ diesel oil, 8 pounds emulsifier (Invermul , NL
Industries, Inc.), 8 pounds amine lignite filtration control
aid (Duratone~, NL Industries, Inc.), 5 pounds lime, 0.20 bbl
of ll.0 lb. per gallon, aqueous calcium chloride, aqueous 320
pounds of barite (Baroid~, NL Industries, Inc.) was admixed,
stirred for 15 minutes in a Hamilton Beach mixer and cooled
to 28F in an ice bath. A 6 lb/bbl concentration of the clays
EM2HT/bentonite, AM2~T/bentonite and A~12HT/hectorite produced
in Examples 2, 3, and 4 respectively in addition to two
commercial clays 2M2~T/bentonite and BM2HT/bentonite described
in Examples 7 and 8 were stirred into the cold fluid batches
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 7QF. The batches were then placed in a preheated
cup jackets set at 125F and allowed to heat to 110DF. 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 Fiqure 1.
Examples ~-13 at 115F were stirred for 15 minutes
in a Hamilton Beach mixer and cooled to 8nF and tested as
with Example 5. The results are presented in Table 3 below.
-14- ~ ~6~03Z
(
Table 3
Yield 10 sec. 10 min.
Point Gel Gel
Example#/ 2 `' #/ 2 ~/ 2
No. lnOft 100ft _ Oft
9 42 15 19
56 22 27
11 68 38 46
12 50 21 26
13 50 23 28
Example 14-17
Fluids consisting of 0.41 bbl of diesel oil and 12
pounds of gellant clays prepared in Example 2 and 3 in
addition to commercial clays 2M2HT/ bentonite and BM2HT/
bentonite were admixed and stirred for five minutes in a
~amilton Beach mixer at low speed. Fluids consis~ing of
0.41 bbl of diesel oil, 18 pounds asphalt (Baroid Asphalt,
NL Industries, Inc.) and 275 pounds of barite, (Baroid~ NL
Industries, Inc.) were prepared and admixed with the prepared
fluids above to form 350 ml batches which stirred for 15
minutes in a Hamilton Beach mixer.
350 ml samples of Examples 14 through 17 were
tested for rheological properties as in Example 5 at 93F.
The results are presented in Table 4 below.
- Table~4
Yield lO sec. lO min.
Point Gel Gel
ExampleGellant #/ #/ #/
No. Compound lOOft2 lOOft2 lOOft2
l4 EM2HT/bentonite 26 7 54
AM2HT/bentonite 30 ll 48
16 2M2HT/bentonite 54 34 74
17 BM2HT/bentonite 25 ll 40
350 ml samples of Examples 14 through 17 were hot
rolled at 150F for 16 hoursO After cooling the batches to
80F, settling of solids were checked prior to measurement
of rheological properties as in Example 5 at 93F. The
results are shown in Table 5 below~
32
-15-
Table 5
Yield 10 sec. 10 min.
Point Gel Gel
Example #/ #/ #/
No. lOOft2 ; lOOft2 lOOfk2
_ _ . . . ..
1457 14 73
1580 38 116
16 91 55 100
17 69 39 108
Example 14 shows improved results when mixed in
a non-aqueous fluid. These results~show improvements in
forming a gel quickly and remaining low at 10 minute gel
indicating a maintenance of pumpability.
Mud cake and filtrates were stirred back into the
respective samples and the batches were aged for 16 hours
at 350~F. 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 6 below.
Table 6
Yield 10 sec. 10 minO
Point Gel Gel
Example ~ #/
No. lOOft2 lOOft2 lOOft2
14 85 11 55
lOS 31 83
16 120 45 82
17 99 41 78
Example 18-21
350 ml batches of fluids consisting of 0.69 bbl of
diesel oil, 6 pounds emulsifier tEZ mul~, NL Industries,
Inc.), 0.12 bbl of water, 225 pounds of barite, (Bario ~,
NL Industries, Inc.), 24 pounds of calcium chloride and 6
pounds of gellant clays EM2HT/bentonite and AM2~T/bentonite
prepared in Example 2 and 3 respectively in addition to
2M2HT/bentonite and BM2HT/bentonite were admixed and
stirred for 20 rninutes in a Hamilton Beach mixer.
350 ml batch of Examples 18 through 21 were tested
for rheological properties as in Example 5 at 88F~ The
results are presented in Table 7 below.
~L~6~32
-16-
Table7
10 sec. 10 min.
Point Gel Gel
Example Gellant ` #/ 2 / 2 / 2
Wo. Gellant Compound lOOft 100ft lOOft
18 EM2HT/bentonite 9 4 5
19 Al~l2HT/bentonite 8 S 6
2M2HT/bentonite 9 5 6
1021 ~M2HT/bentonite 8 4 5
350 ml sample of Example 18 through 21 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 8 below.
Table ~
Yield 10 sec.lO min.
Point Gel Gel
Example#/ 2 #/ 2
No.100ft lOOft 100ft
201~ 11 5 8
lg 11 5 5
8 14
21 g
Mud cake and filtrate were stirred back into the
respective samples and the batches were aged for 16 hours at
350F.
Each batch was cooled to 80F, checked for solids
settling and electrical stability. 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 9 below.
Table 9
Yield 10 sec.lO min.
Point Gel Gel
Example~/ 2 #/ 2#/ 2
No.lOOft lOOft lOOft
18 8 5 5
l9 10 4 5
12 5 6
4021 8 4 5
3Z
-17-
Example 22-27
350 ml batches of packer fluids 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~3~L Industries, Inc.), 8 pounds filtration aid
(Duratone, NL Industries, Inc.), 22 pounds of calcium
chloride, 4 pounds lime and 9 pounds of gellant clays
EM2HT/bentonite, AM2HT/bentonite, and A~2HT/hectorite
prepared in Example 2, 3 and 4 respectively in addition
to three commercial clays, dimethyl di(hydro~enated-tallow)
ammonium chloride, 2~2HT/bentonite; benzyl methyl di-
(hydrogenated-tallow) ammonium chloride, BM2HT/bentonite;
ana dimethyl di(hydrogenated-tallow) ammonium chloride,
2~2HT/hectorite were admixed and stirred for 20 minutes in
a Hamilton Beach mixer.
350 ml sample of Examples 22 through 27 were
tested for rheological properties as in Example 5 at 92 F.
The results are presented in TablelO.
Table lO
Yield10 sec. 10 min.
Point Gel Gel
Example ~/ ~/ 2 2
No. Gellant Compound lOOft2100ft _ 100ft
2522 EM2HT/bentonite 36 11 16
23 AM2HT/bentonite 42 18 23
24 A~2HT/hectorite 55 23 27
2M2HT/bentonite 60 22 33
26 BM2HT/bentonite 51 24 28
3G27 BM2HT/hectorite 65 32 39
Mud cake and and filtrate were stirred back
into each batch and the batches were aged at 350F for 16
hours. Each batch was cooled to 80F, checked for solids
settling and electrical stability. The batches were
admixed, stirred for 10 minutes and tested as with Example
5 at 90F. The results are shown in Table 10 below.
0
... . ~
~L6L3~3Z
-18-
f
Table ll
.
Yield 10 sec. 10 min.
Point Gel Gel
Example / 2 #~ #/
No. lOOft lOOft2 lOOft2
22 20 16 24
23 28 23 27
10 24 31 30 33
34 18 26
26 26 24 29
27 37 28 35
350 ml batches of Examples 23, 24, 25 and 37 were
aged for 16 hours at 300F, 400F and 450F. The batches
were tested as above at 99F and the results are shown in
Tablel2 .
Table 12
Yield 10 sec. 10 min.
Point Gel Gel
ExampleTemperature #/ #/ #/ 2
No. F lOOft2 lOO~t2lOOft
23 300 21 21 23
400 45 14 30
450 13 9 16
25 24 300 31 30 33
400 150 41 57
- 450 80 22 35
300 38 28 37
400 27 11 20
450
27 300 37 28 35
400 120 40 60
450 40 17 30
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.
