Note: Descriptions are shown in the official language in which they were submitted.
~2853
BACKGROUND OF T~E INVFNTION
1. ~ : The invention relates to a new
and improved micellar solution of a thin film spreading agent
comprising polyepoxide condensates of resinous polyalkylene oxide
adducts and polyether polyols which are particularly useful for
breaking or preven~ing petroleum emulsions. More specifically, the
invention relates to a composition in which water replaces all or
a substantial part of the organic solvents formerly required for
preparation of liquid solutions of this interfacially active
compound.
2. ~ : One of the principal uses
of the present composition is in the breaking of petroleum emulsions
to permit the separation thereof into two bulk phases. Much of the
crude petroleum oil produced throughout the world is accompanied
by some water or brine which originates in or adjacent to the geo-
logical formation from which the oil :is produced. The amount of
aqueous phase accompanying the oil may vary from a trace to a very
large percentage of the total fluid produced. ~ue to the natural
occurrence in most petroleum of oi1-soluble or dispersible emulsify-
ing agents, much of the aqueous phase produced with oil is emul-
sified therein, forming stable water-in-oil emulsions.
The literature contains numerous references to such
emulsions, the problems resulting from their occurrence, and the
methods employed to break them and separate salable petroleum.
See, for example, "The Technology of Resolving Petroleum Emulsions"
by L. T. Monson and R. W. Stenzel, p. 535 et seq in Colloid
Chemistry Vol. VI, Ed. by Jerome Alexander, Rheinhold Publishing
Corp., New York (1946) and "Interfacial Films Affecting the
Stability of Petroleum Emulsions" by Chas. M. Blair, Jr. in
ChemistrY and Industr~(London~, p. 538 et seq (1960).
Early demulsifiers used to resolve petroleum emulsions were
water-soluble soaps, Twitchell reagents, and sulfonated glycerides.
These products were readily compounded with water to form easily
1353
pumpable liquids and were conveniently applied by pumping into
flow lines at the well head or by washing down the casing annulus
with water to commingle with well fluids prior to their flow to
the surface. These products, however, were effective only at
relatively high concen~rations and their use added substantially
to the cost of pxoduction~
50me time ago, it was discovered that certain lightly sul-
fonated oi~s, acetylated caster oils and various polyesters, all
of which were insoluble in water but soluble in alcohols and
lQ aromatic hydrocarbons, were much moxe effective in breaking
emulsions. Accordingly, essentially all commercial demulsifier
development has led to production of agents which are insoluble
in both water and petroleum oil~ and have other properties to be
descrlbed below which cause them to spread at oil-water interfaces
to form very thin, mobile films which displace any emulsifying
agent present in the oil to allow coaLescence of dispersed water
droplets. Generally, such interfacially active compounds are
hereafter~ referred to as Thin Pilm Spreading Agents, or "TFSA's".
In the past, these have had to be compounded with and dissolved
in alcohols or highly aromatic hydrocarbon solvents in order to
produce readily applied liquid composi~ions. A wide variety of
such compositions are required to treat the many different emul-
sions encountered throughout the world.
While present TFSA compositions are highly ~fective,
being, perhaps, up to fifty to a hundred times more effective per
unit volume than the origin~l water-soluble demulsifiers, they
suffer serious practical deficlencies because o their solubility
characteristics. For example, alcohols and the aromatic hydro-
carbons, which are required for preparation of liquid, pumpable
compositions, are quite expensive, today approaching in cost that
of the active demulsifier ingredient itself. Further, such solvents
3S3
are flammable and thus create safety problems and entail more
expense in shipping, storing and use. The low flash poin~ ~lam-
mability can be improved by using high boiling aromatic solvents,
but these are increa~ingly rare, expensive and dangerous from the
standpoint of carcinogenicity and dermatological effects.
Still further, present demulsifiers cannot generally be
used in a subterranean oil or gas well, injection well, or the like,
since they cannot be washed down with either water (or brine) or a
portion of the produced oil, and, being viscous liquids which are
required in vexy small amounts, they cannot be reliably and con-
tinuously delivered several thousand feet down at the fluid level
in a typical well without use of elaborate and expensive delivery
means.
Other applications of TFSA compositions would be facili-
tated if they were readily soluble or dispersible in water. For
example, much heavy, viscous oil is produced in the United States
by steam injection procedures. Typically, wet steam is injected
into the oil producing strata for several weeks in order to heat
the oil, lower it3 viscosity and increase reservoir energy. Steam
injection is then stopped and oil is flowed or pumped from the bore
hole which was used for steam injection. Much of the water result-
ing from condensation of the steam is also produced with the oil in
emulsified form. Since emulsions are more viscous than the external
phase at the same temperature, and thus create increased resistance
to flow, productivity of the steamed wells can be improved by in-
jecting a water-soluble demulsifier into the wet steam during the
steam injection period to prevent emulsion formation. See, for
example, U.S. Patent 3,396,792, dated April 1, 1966, to F.D. Muggee.
At present, the requirement of water solubility seriously limits the
choice of demulsifiers for use in steam or water injection to the
relatively inefficient compositions.
~;2853
As disclosed in my co-pending Canadian Applications, Serial
Number 353,251, filed ~une 3, 1980, and entitled "Method Of Re-
covering Petroleum From A Subterranean Reservoir Incorporating
A Polyether Polyol", and Serial Number 353,233, filed June 3,
1980, and entitled "Method Of Recovering Petroleum From A Sub-
terranean Reservoir Incorporating Polyepoxide Condensates Of
Resinous Polyalkylene Oxide Adducts And Polyether Polyols",
TFSA's are useful in processes for enhanced recovery of petrol-
eum. Used in such processes involving displacement oE residual
oil by aqueous solutions, polymer solutions and other aqueous
systems, these agents act to increase the amount of oil recovered.
Such action possibly arises from their ability to further water
wetting of reservoir rock, lessen the viscosity of the oil-water
interfacial layer and promote coalescence of dispersed droplets
of either water or oil in the other phase.
By use of the present aqueous micellar solutions, the
introduction of TFSA into aqueous displacement or flooding
fluids is greatly facilitated. In addition, the present
micellar solutions, per se, or in combination with other com-
ponents, can be used as the flooding agent or as a pretreating
bank or slug ahead of other aqueous fluidso
Other applications for the present TFSA micellar solutions
include their use as flocculation aids for finely ground
hematite and magnetite ores during the desliming step of ore
beneficiation, as additives for improving the oil remo~ral and
detergent action of cleaning compositions and detergents
designed for use on polar
-- 5 --
~i;28S3
materials, for ~he improvement of solvent extraction processes
such as those used in extraction of antibiotic products from
aqueous fermentation broths with organic solvents, for the improve-
ment of efficiency and phase separation in the purification and
concentration of metals by solvent extraction with organic solu-
tions of metal complex-forming agents, and as assistants to improve
the wettiny and dying of natural and synfhetic fibers and for other
processes normally invol~ing the interface between surfaces of
differing polarity or wetting characteristics.
SUMMP.RY OF TEIE INVENTION
A primary object of the present invention is to provide
aqueous, liquid compositions of these TFSA's having new and use~ul
characteristics which allow productio~ o~: petroleum emulsion
breakers and emulsion preventing compositions free or relatively
free of highly flammable and environmentally objectionable aromatic
hydrocarbons; compositions having a comparatively low cost; compo-
sitions which are soluble or dispersihle in water and which, there-
fore, can often be applied by more effective methods than can exist-
ing products; compositions which can be used in enhanced recovery
operations such as steam flooding and aqueous medium flooding where
present products cannot be readily applied; and compositions which
can be compounded with wa~er soluble reagents of other types, such
as corrosion inhibitors, wetting agents, scale inhibitors, biocides,
acids, etc., ~o provide multipurpose compounds for use in solving
many oil well comple~ion, production, transportation and refining
problems.
In accordance with the present invention, these aims are
accomplished by means of amphipathic agents which are capable of
forming micellar solutions and which by this mechanism or other
undefined actions, combined with those of a second essential
~;21353
component which will be referred to as a hydrotropic agent, are
able to form homogeneous aqueous solutions containing a relatively
wide range of concentrations of TFSA.
DESCRIPTION OF THE PREFERRÆD EMBODIMENTS
The TFSA compositions of the present invention can be
broadly categorized by the following general characteristics~
1. Solubility in water and isooctane at about 25~ is
less than about 1~ by volume;
2. Solubility parameter at about 25C is in the range of
from between about 6.8 to about 8.5, with a majority
in the range of from between 7.0 and a~out 7.9; and
3. Spread at the interfaee between white, refined mineral
oil and distilled water to form films having a cal-
culated thickness no greater than about 20 Angstroms
at a spreading pressure O:e about 16 dynes per cm.
TFSA compositions having these properties are generally
organic polymers or semi-polymers having molecular weights ranging
from about 2,000 to about 100,000 and having structures containing
a multiplicity of distributed hydrophilic and hydrophopic moieties
arranged in linear or planar arrays which make them surface active
and lead to their adsorption at oil-water interfaces to form very
thin films.
Unlike most commonly encountered surface-active compounds,
the present TFSA appears to be incapable of forming a micelle in
either oil or water. The distributed and alternating occurrence
of polar and nonpolar or hydrophilic and hydrophobic groups in the
molecule apparently prevents the kind of organization required for
micelle formation and thus impairs dispersion or solution in either
water or low polarity organic solvents.
The TFSA's useful in the present invention have the pre-
viously recited properties:
~;2~S3
1. The solubilit~in water and in isooctane at about
~ '
.
Solubility tests may be run by placing a 1 ml
sample (or the weight of solid product calculated
to have a volume of 1 ml) in a graduated cylinder
of the type which may be closed with a ground glass
stopper. Thereafter place 99 ml of water in the
cylinder, close, place in a 25C water bath until
thermal equilibrium is reached, and remove from the
bath and shake vigorously for one minute. Return
the sample to the bath for five minutes and then
repea~ the shaking procedure. ~inally, return the
sample to the bath and allow it to stand quietly
for one hour. The cylinder contents should be
carefu;ly examined and any cloudiness or opacity
of the liquid phase or the appearance of any sediment
or undissolved material in the cylinder noted, thus
indicating that th sample satis~ied the requirement
for insolubili~y in water.
Isooctane solubility is determined similarly by
substituting this hydrocarbon for ~he water used
above.
2. The Solubili*y Parameter ~S.P~) at _ ou C is from
~.
Methods of determination of solubility parameter
are disclosed in Joel H. Hildebrand, "The Solubility
of Nonelectrolytes", Third Edition, pgs. 425 et seq.
However, a simplified procedure, sufficiently accurate
for quali~ication of a useful TFSA composition may be
utilized. Components of a given solubility parameter
are generally insoluble in hydrocarbon (non-hydrogen-
bonding) solvents having a lower solubility parameter
~iiZ~353
than themselves. Therefore, the present composition
should be soluble in a hydrocarbon solvent of a solu-
bility parameter of about 6.8. Since the solubility
parameter of mixtures of solvents is an additive
function of volume percentage of components in the
mixture, test solutions of the desired solubility
parameters may be easily prepared by blending, for
example, benzene (S.P. 9.15) and isooctane ~SOP~ 6.85)
or perfluoro-n-heptane (S.P. 5~7).
10 ~ A mixture of about~72 parts of benzene with about
28 parts of isooctane will provide a solvent having a
solubi~lity~parameter of about 8.5 at room temperature
(about 25C)~. ~Perfluoro-n-heptane has a solubility
parameter~of about 5~7 al: ~5C, so a mixture of 68
parts of this solvent wi1h 32 parts of benzene
provides a solvent~with a solub1lity parameter of
about 6.8, or isoocta~ne of a solubility parameter
6.85 may be~used.
When 5 ml of the T~SA~are mixed with 95 ml of an
~ 8~5 solubility~parameter~solvent~at room temperature,~
a clear solution~should result.~ When 5 ml of TFSA is
mixed with a 6.85 solubility parameter solvent, a
cloudy mixture or one showlng phase sepaxation shou}d
result. Solvent mixtures have a solubility parametar
between about 7.0 and about 7.9 may be prepared as
described above and utilized in a similar test pro-
cedure.
In interpreting the solubility parameter and other
tests, it should be recognized that the TFSA consists
not of a single material or compound but a cogeneric
mixture of products containing a range of products of
molecular weights distributed around the average
molecular weight and even containing small amounts of
3S3
the starting compounds employed in the synthesis.
As a result, in running solubility and solubility
parameter tests, very slight appearance of cloudiness
or lack of absolute clarity should not be interpreted
as a pass or a faîlure to pass the criteria. The
intent of the test is to ensure that the bulk of the
cogeneric mixture, i.e., 75~ ox more, meets the re~uire-
ment. When the result is in doubt, the solubility
tests may be run in centrifuge tubes allowing sub
sequent rapid phase separation by centrifuging,~ after
which the separated non-solvent phase can be removed,
:
any solvent contained in it can be evaporated, and the
: :
; actual welght or volume~of separated phase can be
determined.
3. ~he T 5A Aho~t ~the~interface between
~ ~ D. erd r:~ined mineral oil to form films
dynes per cm (0.01-6 ~ewton per me-ter)~.
20 ; ~ ; Sultable methods o~ determining~fi~lm pressure~are~
disclosed in N. K. Adam, i'Physics and Chemistry of
Surfaces", Third Editlon, Ox ~ ess,
London, 1941, pgs. 20 et seq, and C. M. Blair, Jr.,
"Interfacial Films Affecting The Stability of Petro-
leum Ernulsions", Chemistxy_and Industry~(London),
1960, pgs. 538 et seq. Film thickness is calculated
on the assumption that all of the TFSA remains on the
area of interface between oil and water on which the
product or its solution in a volatile solvent has
been placed. Since spreading pressure is numeriaally
e~ual to the change in interfacial tension resulting
from spreading of a film, it is conveniently determined
~28~
by making interfacial tension measurements before
and after adding a known amount of TFSA to an inter-
face of known area.
Alternatively, one may utilize an inter~acial
film balance of the Langmuir type such as that
described by J. H. Brooks and B. A. Pethica,
~ 1964), p. 20
et seq, or other methods which have been qualified
for such interfacial spreading pressure determinations.
In determinin~ the interfacial spreading pressure
o the TFSA products, I prefer to use as the oil phase
a fairly available and reproducible oil such as a
clear, refined mineral oil. Such oils are derived
rom petroleum and have been treated wi~h sulfuric
acid and other agents to remove nonhydrocarbon and
aromatic constituents. Typica1 of such oils is
"Nujol", distributed by P~lough, Inc~.~ This oil ranges
in density from about Oo B5 to 0.89 a~d usually has a
solubility parameter between about 6.9 and about 7.5.
~20 Numerous similar~oils of greater or~smaller density
and viscosity are commonly available from chemical
supply houses and pharmacie~s.
Other essentially aliphatic or naph~henic hydro-
carbons of low volatility are equally usable and will
yield similar values of spreading pressure. Suitable
hydrocarbon oils appear in commercial trade as refined
"white oils", "textile lubricants", "paraffin oil",
and the like. Frequently, they may contaln very small
quantities o alpha-tocopherol (Vitamin E) or similar
antioxidants which are oil-soluble and do not inter-
fere with the spreading measurements.
While the existence of micelles and of oily or aqueous
micellar solutions have been known for some time (see, e.g.,
"Surface Activity", Moilliet, Collie and Black, D. Van Nostrand &
Co., New York (1961)) and are probably involved in many operations
involving detergency where either oily(nonpolar) or earthy (highly
polar) soil par~icles are to be removed, their utility in co-
operation with hydrotropic agents for the present purposes is an
unexpected and unpredictable discovery.
In U.S. Patent No. 2,356,205, issued August 22, 1944, to
Chas. M. Blair, Jr. & Sears Lehman~ Jr., a wide variety of micellar
so}utlons designed to dissolve petroleum oils, bitumen, wax, and
other relatively nonpolar compounds are described for purposes of
cleanlng oil formation faces and for effecting~enhanced recovery
o~ petroleum by solution thereof. At this early date, however,
the use of micellar principles was not contemplated for the pre-
parDtion of solutions of~khe relatively high molecular weight
; demulsifiers.
~ owever, some of the principles disclosed i~ the above
patent, omitting the~main ojbective therein of dissolving relatively
large amounts of hydrocarbons, chlorinated hydrocarbons, and the
.
like, are applicable to preparation of the present compositions.
The four necessary components of the micellar solutions
of TFSA are:
1. A mlcelle-forming amyhipathic agent. Such may be
anionic, cationic, or nonionic and, if anionic or
cationic, may be either in salt form or as the free
acid or free base or mixtures thereof.
2. A hydrotropic_agent. This is a small to medium mole-
cular weight semi-polar compound containing oxygen,
nitrogen or sulfur and capable of forming hydrogen
~i2~3
bonds. It is believed that such agents cooperate
in some manner with the amphipathic agent to form
clear or opalescent, stable compositions.
3. Water.
4. TFSA, having the propertles recited above.
In addi~tion to these `component6, the micellar solutions
~ ~ may contain, but are not required to contain, salts, hydrocarbons,
; ~ or small amounts of other inorganic or organic material. Such
~;~ constituents may be impurlties, solvents, or by-products of
10 ~ syntheses used~in forming the hydrotropic agent, or may be ad~itions
Eound useful in forming the~composition of this inv ntion. As an
example of the latter, small amounts~of inorganic salts such as
NaCl, Na2SO4, ICNO3, CaC12, and the like~,~are~sometimes~helpful~in
~pr~omoting~homogeneity~with~a minimum of~ amphipathic and hydrotropic
~agents. They may also yield compositions of lower freezing point,
a property~usefu].~when the composition is employed in cold climates.
S~imilarly,;ethylene glycol, methanol,;~ethanol, acetic~acid~, or ~
similar organic oompounds~may~bé incorporated into~the composi~ions
to~i~mprove~physical properties~such as~freezing point, viscosity,
and~density,~ or~to imprave stabllity. ;
As stated above, the~micelle-formlng amphipathic agents
which may be used ln preparing the aqueous solu~tions hexein ~on-
templated may be either cation-ac~ive, anion-active, or of the~
nonelectrolytic type. Amphipathic agents gener~ally have present
at least one radical containing about 10 or more carbon atoms and
not more than about 64 carbon atoms per molecule. This is true of
the amphipathic agents employed in the present invention as a
component of the vehicle or solvent or dispersant employed in the
presen~ compositions. The hydrophobic portions of these agents
may be aliphatic, alicyclic, alkylalicyclic, aromatic, arylalkyl,
or alkylaromatic. The preferred type of agents are those in
~i;2~3
which the molecule contains a long, uninterrupted carbon chain
containing from 10 to 22 carbon atoms in length. Examples of
suitable anion-active amphipathic agents include the common soaps,
as well as materials such as sodium cetyl sulfate, ammonium lauryl
sulfonate, ammonium di-isopropyl naphthalene sulfonate, sodium
oleyl glyceryl sulfate, mahogany and green sulfonates from petro-
leum or petroleum f~actions or extracts, sodium stearamidoethyl
sulfonate, dodecylbenzene sulfonate, dioctyl sodium sulfosuccinate,
sodium naphthenate, and the like. Other suitable sulfonates are
disclosed and taught in U.S. Patent No. 2,278,171, issued February
17, 1942, to De Groote and Keiser.
Suitable cation-active compounds include cetyl pyridinium
chloride, stearamidoethyl pyridinium chloride, trimethyl-heptadecyl
ammonium chloride, dimethyl~pentadecyl sulfonium bromide, octade-
cylamine acetate, and 2-heptadecyl-3-diethylene diaminoimidazoline
diacetate.
Suitable nonelectrolytic amphipathic agents include the
oleic acid ester of nonaethylene glycol, the steric acid ester of
polyglycerol, oxyethylated alkylphenols, and long chain alcohol
ethers o~ polyethylene glycols.
It is of course, well known that amphipathic compounds
are readily and commercially available, or can be readily prepared
to exhibit the characteristics of more than one o~ the above
mentioned types. Such compounds are disclosed in U.S. Patent No.
2,262,743, dated November 11, 1941, to De Groote, Keiser and Blair.
For convenience, in such instances where a surface-active material
may show the characteristics of more than one of the above descri-
bed types, it is understood that it may be classified under either
or both types.
The mutual solvent or hydrotropic agents of the solution
utilized in the present invention are characterizable as compounds
~ ;2853
of a hydrophobic hydrocarbon residue of comparatively low molecular
weight combined with a hydrophilic group of low moleculax weight
and are free from surface-active properties. The hydrophobic
residue may contain from 2 to 12 carbon atoms and may be alkyl,
alicyclic, aromatic, or alkyl substituted alicyclic or aromatic,
or may be the hydrocarbon portion of a heterocyclic or hydrocarbon
substituted heterocyclic group. The hydrocarbon residue may have
branched or normal c~ain struc~ure, but no bxanch may have a length
of more than 7 carbon atoms from the point of attachment to the
hydrophilic residue, counting a benæene or cyclohexyl group as being
equivalent in length to an aliphatic chain of ~hree carbon atoms.
~here the hydrocarbon residue consists of not more than 4 carbon
atoms, structures of the normal primary alkyl type are preferred.
Where the residue is made up of more than four carbon atoms, then
structures of secondary and tertiary types are also good where the
second and third branches may be methyl or ethyl groups.
This hydrophobic hydrocarbo~ r~sidue is combinea either
directly or indirectly with a hydrophilic group of one of the
following groups:
(a) A hydroxyl group which may be alcoholic, phenolic,
or carboxylic;
(b) An aldehyde group;
tc) A carboxy amide group;
(d) An amine salt group;
(e) An amine group; and
(f) An alkali phenolate group.
By "indirectedly combined with one of these groups" is
meant that the hydrocarbon residue is combined as by eth~rification,
esterification, or amidification, or the like, with another organic
residue which contains not more than four carbon atoms and also
~52853
one or more of the hydrophilic groups named above, provided that
aftex said combination, at least one of the hydrophile groups
remains free. Specific examples illustrating this class of com-
pounds are: Ethyl alcohol, n-amyl alcohol, alphaterpineol, p-cresol,
cyclohexanol, n-butyraldehyde, benzaldehyde, n-butyric acid, glycol
mono butyrate, propyl lactate, mono n-butyl amin~ hydrochloride,
n-propionamid, ethylene glycol mono n-butyl amine hydrochloride,
n-propionamid, ethylene glycol mono n-butyl ether, pyridine, methyl-
ated pyridine, piperidine, or methylated piperidines.
::
l0The solubilizer (mutual solvent or hydrotropic compound
~ above described) i5 essentially a semi-polar liquid in the sense
;~ that any liquid whose polar character is no greater than that of
ethyl alcohol and which shows at least some tendency to dissolve
in water, or ha~e water dissolved in it, is properly designated as
semi-polar.
The solubilizer or semi-polar liquid indicated may be ilIu-
strated by the formula X - Z, in whLch X is a radical having 2 to
12 carbon atoms, and which may be alkyl, alicyclic, aromatic,~
alkylalicyclic, alkylaryl,:arylalkyl, or alicyclicalkyl in naturej
and may, furthermore~, include heterocyclic compounds and s:ubstituted
heterocyclic compoun~ds. There is the added limitation that the
ngest carbon atom chain must be less than eight~:carbon atoms,
: and that, in such characterization, cyclic carbon atoms must be
counted as one-half. Z represents:
/ U / H O / U
\ V ~ \ ; COOH; or -OMe
where U and V are hydrogen or a hydrocarbon substituent and Me is
an alkalie metal;
30 N
if X is a cyclic teritary amine nucleus;
~5Z853
\
NH
if X is a cyclic secondary amine nucleus.
The semi-polar liquid also may be indicated by the follow-
ing formula: - X - Y - R - (Z)n Here X and Z have their previous
significance, R is ~ CH2 - , - C2H4 - , - C3H5~ C3~6 or
~C2H4 - C2 4
and n is either one or two as the choice of R demands. Y is one
of the~following:
- C -N -; - N -C -; C -0 -; - O -C -; - O -; S -.
In general, these hydrotropic agents are liquids having
dielectric constant values between about 6 and about 26, and have
at l ast one polar group containing one or more atoms of oxygen,
and/or nitrogen. It is significant, perhapsj that all of the
solubLlizers are of types known to be able~to form hydrogen bonds.
The choice of solubilizer or common solvent and its pro-
portion in the mixture depends somewhat upon the amphipathic agent
used, the amount and kind of TFSA used, and the proportion of
~ water used, and lS best determined by preparing expPrimental
mixtures on a small scale.
In some cases, it is desirable to include in the solution
small amounts of acid, alkali,~ or inorganic salts, as it has been
found that the presence of these electrolytes often gives solutions
having greaterstability and a wider range of miscibility with
water and organic material. Excess acid, when used, will usually
be in solutions containing a cation-active or nonelectrolytic
wetting agent, but not exclusively so. Excess alkali, when used,
will usually be in a solution containing anion-active wetting
agents, but, again, not exclusively.
~ ~5;2 ~53
The polyether polyol or TFSA utilized in this invention is
generally an organic polymer or semi-polymer with an average mole-
cular weight above about 800 and below about 30,000 and has a
structure which will allow orientation on polar surfaces with much
or most of the elements of the molecule in a thin plane. To be
effectively adsorbed at oil-water or oil-rock interfaces and sub-
sequently to be desorbed at water-rock interfaces, the TFSA must
generally contain constituents which give it a highly distributed
hydrophile and hydrsphobe character, and without such concentrations
of either hydrophilic or hydrophobic groups as to produce water
solubility or oil solubility, in the ordinary macroscopic sense.
The TFSA also appears to differ from formerly used surfactants in
that the effects on oil-water interfacial tensions as a function of
concentration are limited. While sprleading efficiently at such
:
nterfaces to form thin ilms with spreading pressures up to about
35 to 40 dynes per cm, addition or larger amounts of TFSA have
relatively little effect on interfacial tension. Also, ihe present
TFSA constituent o the micellar solution in contrast to formerly
used sur actants~, has relatively little or no tendency to stabilize
~20 either oil-in-water~or water-in-oil emulsions when present in
normal use amounts.
Usually the TFSA const~ituents applicable to the practice
of the invention are organic moleaules containing carbon, hydrogen
and oxygen, although in some ~nstances they may also contain sulfur,
nitrogen, silicon, chlorine, phosphorous or other elements. Small
amounts of inorganic material such as alkalies, acids or salts may
appear in the compositions as neutralizing agents, catalyst resi-
dues or otherwise. The critical requirements for the TFSA composi-
tions are not so much compositional as structural and physical.
They must be made up of hydrophilic (polar) moieties, usually
ones capable of forming hydrogen bonds, such as hydroxyl, carbonyl,
~;28S3
ester, ether, sulfonium, amino, ammonium, phospho or similar
hydrogen bonding groups, connected by or to hydrophobic groups,
such as alkylene, alkyl t cycloalkyl, aryl, arylene, aralkyl, poly-
alkylene, polyalkylyne ! combinations of such groups and such groups
containing relatively non-polar substituents, such as hydrocarbon,
chlorine, fluorine and the like. Sometimes the hydrophobic moie-
ties are larger and contain more atoms than the polar groups in
the molecule, having a minimum of two carbon atoms in each group
and up to as many as 36 carbon atoms, although the actual ratio
of sizes depends greatly on the s~ructure of the hydrophilic moiety.
Most commonly, the hydrophobLc groups will contain 14 to 22 carbon
atoms and will have linear or sheet-like conformations allowing
for relatively flat orientation on surfaces.
Polar moie*ies other than hydrogen bonding ones are not
excluded from these compositions and, indeed, may be deliberately
included in some structures to improve aasorption and interfacial
spreading tendencies. For example, quaternary ammonium groups/
while incapable of forming hydrogen bonds, can improve spreadinq
and interfaciaI adsorption in some applications by way of their
highly ionized foxm which imparks cationic character to the mole-
cules in which they occur and, via coulombic repulsion effects,
can improve spreading in a film.
Generally, the T~SA constituents will contain at least
two each of the required hydrophilic (polar) and hydrophobic
moieties per molecule and commonly will contain many more of each.
The effective products, however, must have the three properties
described above.
While, as pointed out above, ths effective TFSA may be
derived from a wide variety of chemical reactants and may contain
numerous different groups or moieties, T have found that partic-
ularly effect products are those which are described as a
~i;28S3
polyepoxide condensate of at least one of~ a polyalkylene
oxide adduct of a fusible, wa~er-insoluble organic aromatic
hydrocarbon solvent-soluble synthetic resin, wherein said resin
has from between about 4 to about 15 phenolic groups and is an
alkyl or cycloaliphatic substituted phenol-aldehyde condensate of
an ortho- or para-substituted phenol and an aldehyde, said con-
densate resin being thereafter further condensed with an alkylene
oxide containing less than about five carbon atoms in an amount
equal to at least one mole of alkylene oxide per phenolic moiety
of said resin; and (2) a polyether polyol having the formula:
/ [ (A) jH] n
R
\ {NR [(A~kH~ m
wherein:
A~ 1s~an alkylene oxide groups, -CiH2iO-;
O is oxygen;
i is a positive integer no greater than about 10;
j is a positive integer no greater than about lOOi
k is ~ positive inteqer no greater than about 100;
N is nitrogen;
R is one of hydrogen, a monovalent hydrocarbon group containing
less than about Cll, or [AhH];
L is a positive integer no greater than about 100;
R is a hydrocarbon moiety of a polyol, a primary or secondary
amine, a primary or secondary polyamine, a primary or
secondary amino alcohol, or hydrogen; and
m ~ n is no greater than about 4 when R is other than hydrogen
and one of m and n is zero and the other is unity when R is
hydrogen. These polyepoxide condensates must conform to the
physical property parameters set forth above.
The polyalkylene oxide adducts are broadly described in
U.S. Patent 2,499,365, entitled "Chemical Manufacture", dated
853
March 7, 1950, to DeGroote, et al. These compositions also include
materials wherein less than one or two alkylene oxide units may be
reacted with each reactive structural group of the starting resin.
The most common resin is an alkyl or cycloaliphatic sub-
stituted phenol-aldehyde resin prepared by condensing an ortho- or
para-substituted phenol with an aldehyde, most commonly with
formaldehyde or a formaldehyde progenitor such as paraformaldehyde
or trioxane, under mildly alkaline or acidic conditions to form a
fusible and xylene-soluble polymer of low or moderate molecular
weight and which typically will contain from between about 4 to
about 12 phenolic groups. This resin is then condensed, usually
with an alkaline catalyst, with an alkylene oxide or a mixture of
alkylene oxides.
Alkylene oxides suitable for use in preparing the composi-
tions used in the pr~sent process include ethylene oxide, propylene
oxide, butylene oxide, 2-3-epoxy-2-methyl butane, trimethylene
oxide, tetrahydrofuran, glycidol, ancl similar oxide~ containing
less than about 10 carbon atoms. Because of their ~eacti~ity and
relatively low cost, the preferred alkylene oxides for preparing
effective TFSA's are the 1,2-alkylene oxides (oxiranes~ exempli-
fied by ethylene oxide, propylene oxide and butylene oxide. In
the preparation of many TFSA's, more than one alkylene oxide may
be employed either as mixtures of oxides or sequentially to form
block additions of individual alkylene oxide groups.
To be suitable for use in the present process, addition
and condensation of oxide must not be carried to the point of
producing water-soluble products. Where ethylene oxide alone is
condensed with the resin, the amount added preferably will be
between one and five moles per phenolic moiety in the resin. The
actual amount will vary with the size of the alkyl or cycloalkylene
8S3
group attached to the phenol ring as well as, apparently, with
the composition and properties of the oil, aqueous phase and
rock formation encountered in the method.
Where propylene or butylene oxides or mixtures of one or
both of these with ethylene oxide are condensed with the phenolic
resin intermediate, generally a greater amount of such oxides may
be reacted without leading to extremely polar, water-insoluble
products. In contract, the amount of epichlorohydrin or glycerol
chlorohydrin which can be condensed without producing agents not
meeting the solubility and interfacial spreading criteria defined
above is usually somewhat lower.
On a solvent-free weight basis, the amount of alkylene
oxide or mixture of oxides condensed with the resin will fall with-
in the range of about one part oxides to about 10 parts of resin
and up to from betwcen about~l-to-5 and about 3-to-1. The final
product should contain at least about one mole of alkylene oxides
per phenolic moiety of the resin.
Compositions incorporated within the scope of the formula
set forth above for the polyether polyol contain an average of
about l~ or more hydroxyl groups per molecule and are generally
composed of a cogeneric mixture of~products obtained by condensing
alkylene oxides with smaller molacules containing two or more
reactive hydrogens as part of hydroxyl or amino groups.
Representative of these compositions is polypropylene
glycol, having an average molecular weight of about 1,200, to
which about 20% by weight of ethylene oxide has been added. Such
a polyether glycol is theoretically obtainable by condensing about
20 moles of propylene oxide with about one mole of water, followed
by addition of about six moles of ethylene oxide. Alternatively,
one may condense about 20 moles of propylene oxide with a pre-
viously prepared polyethylene glycol of about 240 average molecular
weight.
52~53
Other suitable dihydric alcohols may be obtained by con-
densing alkylene oxides or mixtures of oxides or in successive
steps (blocks) with difunctional (with respect to oxide addition)
compounds, such as ethylene glycol, methyl amine, propylene glycol,
hexamethylene glycol, ethyl ethanolamine, analine, resorcino:L,
hydroquinone and the like.
Trihydric e~her alcohols may be prepared by condensation
of ethylene, propylene or butylene oxides with, for example,
glycerin, ammonia~ triethanolamine, diethanolamine, ethyl ethylene
diamine or similar smaller molecules containing three hydrogens
capable of reacting with alkylene oxides. Similarly, polyether
alcohols with a multiplicity of hydroxyl groups may be obtained by
condensing alkylene oxides with multireactive starting compounds,
such as pentaerythritol, glycerol, N-monobutyl ethylene diamine,
trishydroxymethylaminomethane, ethylene diamine, diethylenetri-
amine, diglycerol, hexamethylene diamine, decylamine and cyclo-
hexylamine. DeGroote, in U.S. Patent No. 2,679,511, describes a
number of amino derived polyols which he subsequently esterfies.
Product 15 200, manufactured and sold by the Dow Chemical Company,
and derived by oxyalkylation of glycerol with a mixture of ethylene
and propylene oxides, is an example of a commercially available
polyol of the kind contemplated herein.
Generally, these compositions will have average molecular
weights of 15,000 or less and will be derived from reactive hydro-
gen compounds having 18 or fewer carbon atoms and 10 or fewer
reactive hydrogens.
Other general descriptions of suitable polyether polyols
coming within the scope of the structure detailed above, along
with methods for carrying out the actual manufacturing steps, are
disclosed in "High Polymers, Vol. XIII, Polyethers," edited by
N.G. Gaylord, John Wiley & Sons, New York, 1963.
~iiZ853
Suitable polyepoxide for condensation with the compounds
set forth above include, particularly, the diglycidyl ether of
dihydroxyphenyl-methylmethane and the lower polymers thereof,
which may be formed as cogeneric mixtures and which have the
general formula:
O\ O
2 2 [ O C6H4 - C (CEI3) 2 - C6H4 - O - CH2 - 1H-CH2-]
o
-O-C6H4-C(CH3) ~ C6H4 ~ CH2 2
wherein n is zero of a positive integer or less than about 6.
Other polyepoxides containing two or more oxirane or epoxy
groups, such as diisobutenyl dioxide, polyepoxypolyglycerols,
; epoxidized linseed oil, epoxidized polybu~adiene or the like, may
also be employed.
The composi~tions suitable for practicing the present
invention are prepared by reacting formaldehyde or a substance
which breaks down to formaldehyde under the reaction conditions,
e.g., paraformaldehyde and trioxane, and a difunctional, with
respect to reaction with formaldehyde, alkyl phenol, often a crude
mixture of alkyl phenols for economic reasons~ by heating the
reaatants between a~out 100 and about 12SC in the presence of a
small amount of an acid catalyst such as sulfamic acid or muriatic
acid or, alternatively, in the presence of an alkaline catalyst
such as sodium hydroxide or sodium methylate and, preferably, under
substantially anhydrous conditions, excepting the water produced
during the reaction. The aqueous distillate which begins to form
is collected and removed from the reaction mixture. After several
hours of heating at temperatures slightly above the boiling point
of water, the mass becomes viscous and is permitted to cool to
about 100 - 105C. At this point, an aromatic hydrocarbon
fraction such as xylene may be added, and heating is resumed.
~;2~353
Further aqueous distillate begins to form, and heating is continued
for an additional number of hours until at least about one mole
of aqueous distillate per mole of the formaldehyde has been dis-
tilled off. Xylene or other hydrocarbon which may be distilled
with the water is returned to the reaction mass. The temperature
at the end of the reaction reaches about 180 - 250C. The product
is permitted to cool to yield the phenol-formaldehyde condensation
product in the aromatic solvent.
The molecular weight of these intermediate condensation
products cannot be ascertained with certainty, but it is estimated
that the resins employed herein should contain from between about
4 to about 15, preferably from about 4 to about 6, phenolic nuclei
per resin molecule. The solubility oE the condensation product in
hydrocarbon solvent would indicate that the resin is a linear or
sheet-like polymer, thus distinguishing it from the more common
phenol-formaldehyde resins of the insoluble cross-linked type.
Having prepared the intermed:iate phenol-formaldehyde
products, the next step is the oxyalkylation of the condensation
products with alkylene oxide~ ~his is achieved by mixing the
i~termediate phenol-formaldehyde conden~a~ion product as is or
contained in the aromatic solvent with a small amount of a suitable
catalyst, usually potassium hydroxide or sodium methylate, in an
autoclave. The condensation product is heated above 100C, and
ethylene oxide, propylene oxide, butylene oxide or mixtures of two
or all three of these oxides, either as a mixture or by sequential
addition of first either one or another of the oxides is charged
into the autoclave until the pressure is in the vicinity of 75 -
100 psi.
The reaction mixture is gradually heated until an exo-
thermic reaction begins. The external heating is then removed,
;2~3~3
and alkylene oxide or oxide mixture is added at such a rate thatthe temperature is maintained between about 130 - 160C in a
pressure range o 30 - 100 psi. After all of the alkylene oxide
has been added, the temperature is maintained for an additional
10 to 20 minutes to assure substantially complete reaction of the
alkylene oxide. The resulting product is the alkylene oxide adduct
of an alkyl phenol-formaldehyde condensation product, in which the
weight ratio of the oxide to the condensation product (on a solvent-
free basis) is between about l-to-10 and about 10-to-1, preferably
between about 1-to-5 and about 3-to-1, and containing at least
about one mole of alkylene oxide per phenolic moiety of the resin.
As to the limits of the various constituents of the mi-
cellar solutions containing TFSA, the ollowing will serve as a
guide, the percentages being by weight:
Percent
TFSA Constituents about 5 to about 75
Hydrotropic Agent about 2 to about 30
Amphipathic Agent about 2 to about 30
Water about 15 to about 90
Although the exact function of the electrolytes previously
referred to is not completely understood, the effect, in part, may
be due to the ability to bind water, i.e., to become hydrated.
This suggests that certain other materials which are highly hydro-
phile in character and clearly differentiated from the classes of
non-polar solvents and semi-polar solubilizers may be the functional
equivalent of an electrolyte. Substances of this class which
ordinarily do not dissociate include glycerol, ethylene glycol,
diglycerol, sugar, glucose, sorbitol, mannitol, and the like.
53
Also, as stated above, these solutions may contain other
organic constituents such as hydrocarbons. These frequently are
used as thinning agents, azetropic distillation aids or reflux
temperature controllers in the manufacture of the TFSA constituent
and may be left therein when the present micellar solutions are
prepared. To the extent that such compounds are present they
appear to compete somewha~ with the TFSA constituent for micelle
space, thus limiting, to some extent, the maximum amount of TFSA
constituent which can be brought into homogeneous solution.
Selection of an effective TFSA composition for a given
petroleum emulsion and determination of the amount required is
usually made by so-called "bottle tests", conducted, in a typical
situation, as follows:
A sample of fresh emulsion is obtained and 100 ml portions
are poured into each of several 180 ml screw top prescription or
similar graduated bottles. Dilute solutions (1~ or 2~) of various
TFSA constituents are prepared in isopropyl alcohol. By means of
a graduated pipette, a small volume of a TFSA solution is added
to a bottle. A similar volume of each composition is added ~o
other bot~les containing emulsion. The bottles are then closed
and transferred to a water bath held at the same temperature as
that employed in the field treating plant. After reaching this
temperature, the bottles are shaken briskly for several minutes.
After the shaking period, the bottles are placed upright
in the water bath and allowed to stand quietly. Periodically, the
volume of the separated water layer is recorded along with obser-
vations on the sharpness of the oil-water interface, appearance
of the oil and clarity of the water phase.
After the standing period, which may range from 30 minutes
to several hours, depending upon the temperature, the viscosity
of the emulsion and the amount of TFSA compositions used, small
~28S3
samples of the oil are removed by pipette or syringe and centri-
fuged to determine the amount of free and emulsified water left
in the oil. The pipette or syringe used to remove the test samples
should be fitted through a stopper or other device which acts as a
position guide to insure that all bottles are sampled at the same
fluid level.
The combined information on residual water and emulsion,
speed of the water separation and interface appearance provides
the basis for selection of the generally most effective TFSA
consti~uent. Where none of the results are satisfactory, the
tests~should be repeated using higher concentrations of TFSA con-
stituents and, conversely, where all results are good and similar,
the tests should ~e repeated at lower concentrations until good
discrimination is possible.
In practicing the process for resolving petroleum emulsions
of the water-in-oil type ~ith the present micellar solution, such
solution is brought into cont~ct wi~h or caused to act upon the
emulsion to be treated, in any of the various methods or apparatus
now generally used to reso1ve or break petroleum emulsions with a
chemical~reagent, the above procedure being used alone or in
combination with other demulsiying procedure, such as the elec-
trical dehydration process.
One type of procedure is to accumulate a volume of emul-
sified oil in a tank and conduct a batch treatment type of demul-
sification procedure to recover clean oil. In this procedure, the
emulsion is admixed with the micellar TFSA solution, for example,
by agitating the tank of emulsion and slowly dripping the micellar
TFSA solution into the emulsion. In some cases, mixing is achieved
by heating the emulsion while dripping in the micellar TFSA solu-
tion, depending upon the convection currents in the emulsion toproduce satisfactory admixture. In a third modification of this
~ii28S3 `
type of treatment, a circulating pump withdraws emulsion from,
e.g., the bottom of the tank and reintroduces it into the top of
the tank, the micellar TFSA solution being added, for example, at
the suction side of said circulating pump.
In a second type of treating procedure, the micellar TFSA
solution is introduced into the well fluids at the wellhead, or
at some point between the wellhead and the final oil storage tank,
by means of an ad~ustable proportioning mechanism or proportioning
pump. Ordinarily, the flow of fluids through the subsequent lines
and fittings suffices to produce the desired degree of mixing of
micellar TFSA solution and emulsion, although, in some instances,
additional mixing devices may be introduced into the flow system.
In this general procedure, the system may include various mechanical
devices for withdrawing free water, separating entrained wa~e~r, or
accomplishing quiescent settling of the chemically treated emulsion.
Heating devices may likewise be incorporated in any of the treat-
- ing procedures described herein
A third type of application (down-the hole~ of micellar
TFSA solution to emulsion ls to introduce the micellar solution
either periodically or continuously in diluted form into the well
and to allow it to come to the surface with the well fluids, and
then to flow the chemical-containing emulsion through any desirable
surface equipment, such as employed in the other treating proceduresO
This particular type of application is especially useful when the
micellar solution is used in connection with acidification of
calcareous oil-bearing strata, especially if dissolved in th~ acid
employed for acidification.
In all cases, it will be apparent from the oregoing
description, the broad process consists simply in introducing a
relatively small proportion of micellar TFSA solution into a
relatively large proportion of emulsion, admixing the chemical and
353`
emulsion either through natural flow, or through special apparatus,
with or without the application of heat, and allowing the mixture
to stand quiescent until the undesirable watex content of the
emulsion separates and settles from the mass.
Besides their utility for breaking petroleum emulsions,
the present micellar TFSA solu~ions, as mentioned earlier, may be
used to prevent emulsion formation in steam flooding, in secondary
waterflooding, in acidizing of oil-producing formations, and the
like.
Petroleum oils, even after demulsification, may contain
substantial amounts of inorganic salts, either in solid form or
as small remaining brine droplets. For this reason, most petroleum
oils are desalted prior to refining. The desalting step is
effected by adding and mixing with the oil a few volume percentages
of fresh water to contact the brine and salt. In the absence of
demulsifier, such added water would also become emulsified with-
out effecting its washing action. The present micellar solutions
may be added to the fresh water to prevent its emulsification and
to aid in phase separation and removal of salt by the desalting
process. Alternatively, if desiredt they may be added to the oil
phase as are present aromatic solvent compositions.
Most petroleum oil, alon~ with its accompanying brines and
gases, is corrosive to steel and other metallic structures with
which it comes in contact. Well tubing, casing, flow lines,
separators and lease tanks are often seriously attacked by well
fluids, especially where acidic gases such as H2S or CO2 are
produced with the liquids, but also in systems free of such gases.
It has been known for some time, and as exemplified in
U.S. Patent 2,466,517, issued April 5, 1949, to Chas. M. Blair and
Wm. F. Gross, that such corrosive attack of crude oil fluids can be
353
mitigated or prevented by addition to the fluids of small amounts
of organic inhibitors. Effective inhibitors compositions for this
use are usually semi-polar, surface active compounds containing a
nonpolar hydrocarbon moiety attached to one or more polar groups
containing nitrogen, oxygen or sulfur or combinations of such
elements. Generally these inhibitors or their salts are soluble
in oil and/or water ~brine) and frequently appear to be able to
form micelles in one or both of these phases. Typical inhibitors
include amines such as octyl amine, dodecyl amine, dioctodecyl
amine, butyl naphthyl amine, dicyclohexyl amine, benzyl dimethyl-
dodecyl ammonium chloride, hexadecylaminopropyl amine, decyloxy-
propyl amine, mixed amines prepared by hydrogenation of nitrile
derivatives of tall oil fatty acids, soya acid esters of mono-
ethanol amine, 2-undecyl, l-amino ethyl îmidaæoline and a wide
variety of cationic nitrogen compounds of semi-polar character~
Also effective in some applications are nonyl succinic acid,
diocylnaphthalene sulfonic acid, trimeric and dimeric fatty acids,
propargyl alcohol, mercaptobenzothiozole, 2, 4, 6~trimethyl- 1,
3, 5-trithiaane, hexadecyldimethyl benzimidazolium bromide, 2-
thiobutyl-N-tetrodecyIpyridinium chloride, tetrahydronaphthylthio-
morpholine, and the like.
In contrast to the TFSA, corrosion inhibitors appear to
function by forming on the metal surface strongly adherent, thick,
closely packed films which pravent or lessen contact of corrosive
fluids and gases with the metal and interfere with ionic and
electron transfer reactions involved in the corrosion process.
Corrosion inhibitors are quite commonly introduced down
the casing annulus of oil wells where they commingle with the well
fluids before their travel up the well tubing and thus can effec-
tively prevent corrosion of well equipment. Where corrosive attack
353
occurs at the surface, the inhibitor may be introduced at or nearthe well head, allowing it to adsorb on the flow lines and surface
equipment to insuxe protection.
~ ddition of inhibitor at either downhole or surface loca-
tions may be combined conveni~ntly with demulsifier addition since
the latter is also frequently introduced in one of these locations.
Inhibitors such as those mentioned above, may generally
be incorporated into the TFSA micellar solutions, replacing a
portion of or in addition to the TFSA constituent. Also, since
many of these inhibitors are themselves micelle-forming amphipathic
agents, they may be included in the micellar solution as such,
replacing other amphipathic agents which might be otherwise utilized.
Combining the micellar solution with corrosion inhibitor permits
more economic chemical treatment by reducing inventory to one
compound, requiring only one chemical injection system rather than
two and lessening the labor and super~vision required.
Still another important e~fect of using the micellar solu-
tion of TFSA and corrosion inhibitor results from the prevention of
emulsification by the inhibitor. Frequently, it has been found
that inhibitor in the amount required for effective protection
causes the formation of very refractive emulsions of water and
hydrocarbon, especially in systems containing light, normally non-
emulsifying hydrocarbons such as distillate, casing head gasoline,
kerosene, diesel fuel and various refinery fractions. Inhibitors
are commonly used in refinery systems where emulsification is
highly objectionable and where the compositions could be designed
to include an effective emulsion preventative micellar solution
of TFSA.
Inhibitor use may range from a few to several hundred parts
per million based on the oil to be treated, depending upon the
severity of corrosion. For a given oil field or group of wells,
53
tests will normally be run to determine the requirement for micellar
solution of TFSA and for inhibitor and a composition incorporating
these components in approximately the desired ratio will be pre-
pared. In some instances, the requirement for micellar solution
of TFSA in the best concentration may result in use of corrosion
inhibitor, employed as micelle-former, in some excess over that
required for inhibition. This will not affect the utility of the
micellar solution and will provide a comfortable excess of inhibi-
tion which can be helpful during the periods when higher corro
sivity may be encountered.
Examples of micellar solutions employing TFSA with in-
hibitor in water dispersible, micellar solutions are given below.
Selection of the proper corrosion inhibitor for a given
system or oil LS usualIy made by conducting laboratory tests under
conditions simulating those encountered in the well or flowllne.
Such tests are exemplified by that described in Item No. lK155~
"Proposed Standardized Laboratory Procedure for Screening Corrosion
Inhibitors for Oil and Gas Wells", published by the National
A~ssociation of Corrosion Engineers, Houston, Texas.
EXAMPLES OF THIN FILM SPREADING AGENTS
EXAMPLE lA ~ ~
RESINOUS POLYALK ENB OXIDE ADDUCT PRECURSER
Reference is made to U.S. Patent No. 2,499,365, to M.
De Groote, issued March 7, 1950, which describes generally the
manufacture of demulsifiers by the oxyalkylation of fusible,
organic solvent-soluble, alkylphenol resins. The procedure of
Example 74a o~ this patent was followed to prepare a fusible,
xylene soluble p-dodecylphenol resin in xylene solution. The acid
catalyst was neutralized, water was removed by azetropic dis-
8S3
tillation of some zylene and 0.5% by weight of sodium mekhylate
catalyst was added. Using the procedure of Example lb of the
cited patent, 25% by weight of ethylene oxide, based on the final
batch weight, was added and reacted with the resin.
EX~MPLB IB
FINAL PRODUCT PREPARATION
~ _ . . .. _
Reference i5 made to U.S. Patent No. 3,383,325 to VoL~
Seale, et al, dated May 14, 1968, which described demulsifiers
prepared by condensing polyether polyols and oxyalkylated
~10 alkylphenol resins with diglycidyl ethers of bis-phenol com-
pounds.
One hundred parts of the product of Example 1, in co-
pending Canadian Application, Serial No. 361,281, filed
September 3, 1980, entitled "MiceIlar Solutions Of Thin Film
Spreading Agenks Comprising A Polyether Polyol", was reacted
with 15 parts of the diglycidyl ether of bis-phenol A, followed
; by reacting with 80 parts of the product of Example IA, above,
all in accordance with the procedure of the Seale, et al,
patent, Example D8. Addition of the final 300 parts of SO
~20 extract was omitted. This product meets the three criteria for
thin film spreading agent.
EXAMPLF. II
The procedure employed in Example 44a of U.S. Patenk
2,499,365, to M. DeGrooke, issued March 7, 1950, was followed
ko produce an alkaline catalyzed, fusible, xylene-soluble p-
tertiary amylphenol resin.
Using the procedure described under Example IA, above,
1,000 lbs. of this resin solukion was reacted with 1,000 lbs. of
a mixture of 150 lbs. of butylene oxide, 250 lbs. of propylene
oxide and 600 lbs. of ethylene oxide.
- 34 -
3~5~:8S3
After completion of the oxide addition, the temperature
was adjusted to 140C and 70 lbs. of dimethyl, diglycidyl hydantoin
dissolved in 250 lbs. of xylene was slowly introduced with rapid
stirring. After completion of the epoxy hydantoin addition,
stirring and heating at 140C was continued until the batch
viscosity at 100C was between 1,500 and 2,000 centipoises.
EX~MPLE III
The procedure of Example I was followed except that con-
densation with the oxylalkylated phenolic resin and final addition
of SO2 extract were both deleted.
The product was an effective demulsifier meeting the cri-
teria described above, therefor. This product was also found to
improve the percentage of oiI recovery when used as an additive to
water used in experimental secondary waterflooding tests.
EXAMPLE IV ~
~ The procedure of Example I is followed, except that L2
;~ parts o Ciba-Geigy Resin XB2818, an alkylated dihydantoin contain-
ing three epoxide groups, was substituted for the 15 parts of
di~lycidyl ether used in Example I. Reaction was continued until
the product exhibited a viscosity of about 1,500 centipoises at
100C. The final product met the three criteria for ~FSA.
EXAMPLE V
Into a 500 gal. stainless steel autoclave equipped with
stirrer, steam jacket, cooling coils and appropriate inlet and
outlet lines was introduced 1,000 lbs. of commercial polypropylene
glycol with average molecular weight of 4,000. Sixteen pounds of
a 50% aqueous solution of potassium hydroxide was then added to
the glycol. Steam was admitted to the ~acket and the contents
were stirred while the temperature was brought to about 125C.
~;2853
A slow stream of nitrogen was blown through the vessel
contents during the heating period to effect removal of water.
Ni-trogen sparging was stopped when a sample of the glyol showed
a water content below 0.1%.
At this point, commercial epoxidized soyabean oil containing
an average of three epoxy groups per glyceride molecule was added
at aslow continuous rate while the temperature was increased to
145C. Addi.tion was stopped after 90 lbs. of epoxidized soyabean
oil had been introduced. Stirring and heating at 145C was con-
tinued until the reaction mixture had a viscosity within ~he
range of 1,200 to 1,400 centipoises when measured at 100C.
EXAMPLES OF MICELLAR SOLUT:ION'S INCORP'ORATING TFSA'S
_ ~ _ _ ... . ..
'EXAMPLE'A
Wt. %
Product of Example II 38
Isopropanol 16
Dodecylbenzene sulfonic acid 16
Diethylene triamine 4
Water 26
This product is an effective emulsion breaker for emulsions
produced in the Glendive field of Montana and is particularly
useful as a synergistic component when combined with other
aqueous TFSA compositions such as described in my co-pending
Canadian Application, Serial No. 361,788, filed October 8, 1980,
entitled "Micellar Solutions Of Thin Film Spreading Agents
Comprising Polyepoxide Condensates Of Resinous Polyalkylene
Oxide Adducts And Polyether Polyols".
- 36 -
~2Y~5~ -
EXAMPLE B
Wt. %
Product of Example III 25
Xylene 8
Sodium salt of p-nonylphenoxy-
pentaethoxy sulfuric acid 15
Isopropanol 31
Methanol 6
Water 15
This is a solution of very low pour point which is suitable
for use as a demulsifier in oil fields where ambient temperatures
are well below freezing.
EX~MPLE C
Wt.
Product of Example III 31.3
Isopropanol` 31.2
Ammonium, nonylphenoxyethoxy sulfate 15.6
Sodium acetate ~ ;~ 0.2
Water 21.7
~:
Among procedures which~have~been found useful in selecting
effective micellar TFSA solutions for this use, one involves a
determination of oil displacement efficiency frcm prepared oil-
containing rock cores in equipmen~ described below. A tube of
glass or transparent polymethacrylate ester, having an inslde
diameter of about 3.5 cm (1~ in.) and a length of about 45 cm
(18 in.), is fitted with inlet connections and appropriàte valves
at each end. The tube is mounted vertically on a rack in an air
bath equipped with a fan, heater and thermostat which allows
selection and maintenance of temperatur~s in the range of between
about 25 - 130C.
~28S3
To select an effective micellar TFSA solution for use in
a given oil formation, samples of the oil, of the producing rock
formation and of the water to be used in the flooding operation
were obtained. The formation rock is extracted with toluene to
remove oil, is dried and is then ground in a ball mill to the
point where a large percen~age passes a 40 mesh sieve. The
fraction between 60 and 100 mesh in size is retained. The tube
described above is removed from the air bath, opened and, after
insertion of a glass wool retainer at the lower end, is packed
with the ground formation rock. The tube is tapped gently from
time-to-time during filling to ensure close packing and is visually
inspected to assure absence of voids.
The tube is then returned to the air bath, connected to
the inlet tubing, the temperature is adjusted to the oil formation
temperature and water representative of that produced from the
formation is admitted slowly through the bottom line from a cali-
brated reservoir in an amount just sufficient to fill the packed
rock plug in the tube. This volume is determined from the cali-
brations and is referred to as the "pore volume", being that
volume of water just sufficient to fill the pores or interstices
of the packed plug rock.
The upper line to the reservoir is then connected to a
calibrated reservoir containing the oil representing that from
the formation to be flooded. By proper manipulation of valves,
the line is filled with oil which is then slowly pumped into the
core from the reservoir after the lower valve is opened to allow
displacement of the formation water.
As breakthrough of oil at the bottom is noted, pumping is
stopped and the volume of oil introduced into the sand is deter-
mined from the reservoir readings. This is referred to as thevolume of oil in place. ~he tube of sand containing oil is then
~;Z853
left in the air bath at the temperature of the formation for a
period of three days to allow establishment of equilibrium between
the ground formation rock and the oil with respect to adsorption
of oil constituents on the rock and lowering of interfacial tension.
The time allowed for equilibrium may be varied widely. At higher
temperatures, the time re~uired to reach equilibrium is probably
reduced. Usually, for comparative tests, three days are allowed
to age the oil-rock plug. Results with this procedure closely
simulate work with actual cores of oil-bearing rock.
The oil and water samples used for test purposes are
preferably taken under an inert gas such as high purity nitrogen,
and are maintained out of contact with air during all minipulations
in order to prevent oxidation of the oil and concomitant intro-
duction of spurious polar, surface-active constituents in the oil.
At this point, the rock-oil system simulates the original oil
formation before primary production oil has commenced and well
before any secondary waterflood operation.
The upper inlet line to the t~be is now connected to the
sample of water used in the flooding of the oil formation and, by
means of a syringe pump or similar very small volume positive
displacement pump, the water is pumped in~o the sand body from
the top to displace fluids out of the bottom tubing connection
into a calibra~ed receiver. The pumping rate is adjusted to one
~ simulating the rate of flood water advance in an actual operation,
which is usually in a range of 1 to 50 cm per day. Pumping is
maintained at this rate until two pore volumes of water have been
pumped through the sand.
The volumes of fluids collected in the receiver are measured
and the relative amount of oil and water displaced from the rock
sample are determined and recorded. Of special interest is the
volume of oil displaced as a fraction of the original pore volume.
53
This information may be viewed as an indication of the approximate
percentage of oil originally in place which is produced by natural
water drive following drilling of a well into the rock formation
followed by the primary phase of field production carried to the
approximate economic limit.
Following this step, one to three additional pore volumes
of water containing the TFSA micellar solution to be tested are
pumped slowly through the plug and the volumes of additional oil
and water displaced are determined. Typically, where such an
initial "slug" of micellar TFSA solution is introduced, it may be
contained in a volume of fluid ranging from 1% to 100~ of the pore
volume, but most frequently it will be in a slug volume of 10% to
50% of pore volume.
After this final displacement step, the produced oil and
water are again measured. By comparing the amount of oil produced
by this additional injection of water containing, or preceded by
a solution, of micellar TFSA solution with the amount produced
when the same volume of water containing no TFSA solution is in-
jected, one can evaluate the effectiveness of the particular
micellar TFSA solution used for enhancing the recovery of additional
oil over and above that obtained by ordinary waterflooding.
Generally, six or more sand columns of the kind described
above are mounted in the heated air bath. Test of a given micellar
TFSA solution is then run in triplicate, using identical conditions
and concentrations, simultaneously with three blank tests run
similarly but without addition of micellar TFSA solution to the
water.
The composition of Example C was tested by this procedure
with the following conditions:
Oil -- East Texas Field
API Gravity approximately 40.4
_ an _
~;2~353
Water -- Mixed water used in flood operations
Airbath Temperature -- 150 F tSame as formation tempera-
ture)
Oil was displaced by pumping two pore volumes of water
into the sand. After measuring the volumes o~ oil and water pro-
duced through the bottom line, a further 0.2 pore volumes of water
containing 3,500 ppm of the composition of Example C was injected
followed by 2.8 volumes of water containing 200 ppm of the compo-
sition of Example C. Measurement of the volume~ of oil and water
produced were read after each 0.2 pore volumes of wa~er was
injected.
Results of this test at the points of 2,3 and 5 pore volumes
of injected water are given in the table ~elow wherein averages of
three duplicate determinations are presented.
Oil Recovery ~s % of
_ Oi1~in Place
Composition of Ratio of Increment
Example C of Oil Production
ore Volumes~ Added to Water A~ter Initial 2 P.V.
(P.V.) o~ Water No Chemical after Initial Chemical/No Chemical
Injec~ed Addition 2 P.V. of Water
- ~ ~
2 40.1 40.1
3 43.2 46.2 2.0
a6~o 50.0 1.68
Use of the composition of Example C in the amounts glven
above resulted in the production of 100% more oil from in~ection of
on~ incremental pore volume of water than was produced by water
injection alone and gave 68~ more oil after three incremental pore
volumes of treated water injection.
Although the invention has been described in terms of
specified embodiments which are set forth in detail, it should be
understood that this is by illustration only and that the invention
is not necessarily limited thereto, since alternative embodiments
and operating techniques will become apparent to those skilled in
the art in view of the disclosure. Accordingly, modifications are
contemplated which can be made without departing from the spirit of
the described invention.
