Note: Descriptions are shown in the official language in which they were submitted.
359L'
BACKGROUND OF THE INVENTION
1. ~13LD 0~ tlO~: The invention relates to a new and
improved micellar solution of a thin film spreading agent comprising
an acylated polyether polyol which is particularly useful for break-
ing or preventing petroleum emulsions. More specifically, the
invention rela~es to a composition in which water replaces all or a
substantial part of the organic solvents formerly required for
preparation of liquid solutions oE this interfacially active compound.
2. DESCRIP~o~ IO~ A~l: One of the principal uses of
the presen~ composition is in the breaking of petroleum emulsions
to permit thP separation thereof into two bulk phases. Uuch of the
crude petroleum oil produced throughout the world is accompanied by
some water or brine which originates in or adjacent to the geological
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 o~ the total fluid produced. ~ue to the natural occur-
rence in most petrolèum of oil-soluble or dispersible emulsifying
~,
agents, much of the aqueous phase produced with oil is emulsified
therein, forming sta~le water-in-oil emulsions.~
The literature contains numerous reerences to such
emulsions, the problems resul~ing from their occurrence, and the
methods employed to break them and separate sal ble 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 Filrns Affecting the Stability of
Petroleum Emulsions" by Chas. M. Blair, Jr. in C ~ d Industry
(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
~'
8~ .
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 tha
surface. These products, however, were effective only at relatively
high concentrations and their use added substantially to the cost
of production.
Some time ago, it was discovexed that certain lightly sul-
fonated oils, acetylated caster oils and various polyesters, all of
which were insoluble in water but soluble in alcohols and aromatic
hydrocarbons, were much more effective in breaking emulsions.
Accordingly, esqentially all commercial demulsifier development has
led to production of agents which are insoluble in both water and
petroleum oils and have other properties to be described 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 coa1escence of dispersed water droplets. Generally,
such interfacially active compounds are hereafter referred to as
Thin Film Spreading Agents, or "TF5A'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 compositions. A wide variety of such compositions are
required to trea~ the many different emulsions encountered throughout
the world.
While present TFSA compositions are highly effective, being,
perhaps, up to fifty to a hunared times more effective per unit
volume than the original water-soluble demulsifiers, they suffer
serious practical deficiencies because of their solubility charac-
teristics. For example, alcohols and the aromatic hydrocarbons,
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 are flammable
~L5;~1~54
and thus create safety problems and entail more expense in shipping,
storing and use. The low flash point flammability can be improved
by using high boiling aromatic solvents, but these are increasingly
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 very small amoun~s, 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 dalivery
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 p~oduced in the United States
by s~eam in~ection procedures. Typically, we~ steam is injec~ed
into the oil producing strata for several weeks in order to heat
the oil, lower its vlscosity and increase reservoir energy. Steam
20 iniection i8 then stopped and oil is flowed or pumped from the
bore hole which was used for steam injection. Much of the water
resulting from condensation o~ the steam is also produced with the
oil in emuisified 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 injecting a water-soluble demulsifier into the wet -
steam during the ste~m 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 solu-
bility seriously limits the choice of demulsifiers for use insteam or water injection to the relatively inefficient compositions.
~l~Z85~
As disclosed in my co-pending Canadian applications,
Serial Number 353,251, filed ~une 3, 1980 and entitled "Method
Of Recovering Petroleum From A Subterranean Reservoir Incor-
porating A Polyether Polyol", and Serial Number 353,233, filed
June 3, 1980, and entitled "Method of Recovering Petroleum
From A Subterranean Reservoir Incorporationg Polyepo~ide Con-
densates Of Resinous Polyalkylene Oxide Adducts And Polyether
Polyols", TF5A's are useful in processes for enhanced recovery
of petroleum. Used in such processes involving displacement
of 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 abil-
ity to further water wetting of reservoir rock, lessen the vis-
cosity of the oil-water interfacial layer and promote coales-
cence of dispersed droplets of either water or oil in the other
,
phase.
By use of the present aqueous micellar solutions, the in-
troduction of TFSA into aqueous displacement or flooding fluids
is greatly facilitated. In addition, the present micellar
solutions, per se, or in combination with other components, can
be used as the flooding agent or as a pretreating bank or slug
ahead of other aqueous fluids.
other applications for the present TFSA micellar solutions
include their use as flocculation aids for finely ground hema-
tite and magnetite ores during the desliming step of ore bene-
ficiation, as additives for improviny the oil removal and de-
tergent action of cleaning compositions and detergents designed
for use on polar
s~ ~
materials, for the improvement of solvent extraction processes
such as those used in ex~raction 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 extrac~ion with organic solutions
of metal complex-forming agents, and as assistants to improve the
wetting and dying of natural and synethetic fibers and for other
processes normally involving the interface between surfaces of
differing polarity or wetting characteristics.
SUMMARY OF THE INVENTION
A primary object of the present invention is to provide
aqueous, liquid compositions of these TFSA's having new and useful
characteristics which allow production of: petxoleum emulsion
breakers and emulsion preventing compositions free or relatively
free of highly flammable and environmentally objectionable aromatic
hydrocarbons; compositions having a comparati~ely low cost; compo-
sitions which are soluble or dispersible in water and which, there-
fore, can often be applied by mor~ effective methods than can
existing produc~s; 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 Gompounded with water-soluble reagents
of other types, such as corrosion inhibitors, wetting agents, scale
inhibitors, biocides, acidsl etc., to provide multipurpose compounds
for use in solving many oil well completion, production, trans-
portation 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
8~4
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 T~IE PREFERRED 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 25C
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 about 7.9; and
; 3. Spread at the interface 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 of 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 absorption at oil-water interfaces to form very thin films.
Unlike most commonly encountered surface-active compounds,
the present TFSA appears to be lncapable 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 previously
recited properties:
~285~
1. The solubility in Water and in lsooctane a* about
:~.
Solubility tests may be run by placing~a 1 ml
sample tor 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 repeat the shaking procedure. Finally,
return the sample to the bath and allow it to stand
quletly for one hour. The cylinder contents should be
carefully examined and any cLoudiness or opacity of the
liquid phase or the appearance of any sediment or un~
dissolved material in the cyLinder noted, thus indicat-
ing that the sample satisfied the requirement for
insolubility in water.
Isooctane solubility is determined similarly by
substituting this hydrocarbon fox the water used above.
2. The Solubility ~arameter (S.P.) at about 25C is from
b'etween about'6.9 ahd about 8.5, inclusive
, ~. . ~ ~
Methods of determination of solubility parameter
are disclosed in Joel H. Hildebrand, i'The Solubility
of Nonelectrolytes", Third Edition, pgs. 425 et seq~
However, a simplified procedure, sufficiently accurate
for qualification of ~ useful TFSA composition may be
utilized. Components of a give solubility parameter
are generally insoluble in hydrocarbon (non-hydrogen-
bonding) solvents ha~ing a lower solubility parameter
than themselves. Therefore, the present composition
~5Z8S~ .
should be insoluble in a hydrocarbon solvent of a
solubility parameter of about 6.8. Since the solu-
bility 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 (S.P. 6.85)
or perfluoro-n-hep~ane (S.P. 5.7).
A mixture of about 72 parts of benzene with about
; 10 28 paxts of isooctane will provide a solvent having a
solubility parameter of about 8.5 at room temperature
(about 25C). Perfluoro-n-heptane has a solubility
parameter of about 5.7 at 25C, so a mixture of 68
parts of this solven~ with 32 parts of benzene provides
a solvent wlth a solubility~parameter of about 698, or
isooctane of a solubility parameter 6.85 may be used.
When 5 ml of th~ TF9A are mixed with 95 ml of an
8.5~solubilitv parameter ~oIvent at room temperature,
a clear solution should result. When 5 ml of TFSA is
mixed with a 6.85 solubility parameter svlvent, a
cloudy mixture or one showing phase separation should
,
result. Solvent mixtures have a solubility parameter
between about 7.0 and about 7.9 may be prepared as
described above and utilized in a similar test procedure.
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
854
the starting compounds employed in the synthesis.
As a xesult, in running solubility and solubility
parameter tests, very slight appearances of cloudi-
ness or lack of absolute clarity should not be inter-
preted as a pass or a failure to pass the criteria.
The intent of the test is to ensure that the bulk of
the cogeneric mixture, i.e., 75~ or more, meets the
requirement. When the result is in doubt, the solu-
bility tests may be run in centrifuge tubes allowing
subsequent 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 weight or volum~ of separated phase can
be determined.
3. The TFSA should spread at tha interface between diskilled
water _hd refined mlneral oi~ to form fi-lms with thick-
ness~ no g-reatex than about 20 Angstroms (0 0020 micro-
meter) at a film Pressure of about 16 dYnes ~er cm
(0.016 Newton Per meter)
~ Suitable methods of determining film pressure are
disc1Osed~i~ N. K. Adam, "Physics and Chemistry of
' Surfaces", Third Edition, ~ ~s,
London, 1941, pgs. 20 et seq, and C. M. Blaix, ~r.,
"Interfacial Films Affecting The Stability of Petroleum
Emulsions", Chemistry and_Industr~ (London), 1960, pgs.
538 et seq. Film thickness is calculated on the assump-
tion that all of the TFSA remains on the area of inter-
~ace between oil and water on which the product or its
solution in a volatile solvent has been placed. Since
spreading pressure is numerically equal to the change
in interfacial tension resulting from spreading of a
film, it is conveniently determined by making interfacial
~28S~ .
tension measurements before and after adding a
known amount of TFSA to an interface of known area.
Alterna~ively, one may utilize an interfacial
film balance of the Langmuir type such as that described
by J. H. Brooks and B. A. Pethica, Transactions of the
Faraday Soc ~ (1964), p.. 20 et seq, or other methods
which ha~e been qualified for such interfacial spread-
ing pressure determinations.
In determining the interfacial spreading pressure
of the TFSA products, I prefer to use as the oil phase
a fairly~avallahle~and reproducible oil such as a
clear, refined~mineral oil. Such oils are derived
from petroleum and have been treated with sulfuric
acid and other agents:to remove nonhydrocarbon and :
aromatic constituents. Typical of such oils is "Nujol",
distributed~by Plough, Inc. This oil ranges in density
:
from about 0.85 to 0~89 and usually has a solubility
parameter between about 6.9 and about 7.5. Mumerous
similar oils of greater or smaller density and viscosity
are commonly available from c~hemical supply houses and
pharmacies.
Other essentially aliphatic or naphthenic hydro-
carbons of low vola ility 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 contain very small
quantities of alpha-tocopherol (Vitamin El or similar
antioxidants which are oil-soluble and do not interfere
with ~he spreading measurements.
5~ .
While the existence of micelles and o 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 opera-
tions involving detergency where either oily (nonpolar) or earthy
(highly polar) soil particles are to be removed, their utility in
cooperation 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
solutions designed to dissolve petroleum oils, bitumen, wax, and
other relatively nonpolar compounds are described for purposes of
cleaning oil forma~ion faces and for effecting enhanced recovery
of petroleum by solution thereof. ~t this early date~ however,
the use of micellar principles was not contemplated for the
preparation of solutions of ~he relatively high mQlecular weight
demulsifiers.
However, some of the principles disclosed in the above
patent, omitting the main objective therein of dissolving rela-
tively 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 rnicelle-~ormin~ amphipathic 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 hydrotro~ic a~ent. This is a small to medium mole-
cular weight semi-polar compound containing oxygen,
nitrogen or sulfur and capable of forming hydrogen bonds.
~iZ8S~
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 properties recited above.
In additi.on to these components, 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 impurities, solvents, or by-products of
syntheses used in forming the hydrotropic agent, or may be addi-
tions found useful in forming the composition of this invention.
As an example of the latter, small amounts of inorganlc salts
such as NaCl, Na2SO4, KNO3, CaC12, and the likel are sometimes
helpful in promoting homogeneity with a minimum of amphipathic
and hydrotropic agents. They may also yield compositions of lower
freezing point, a property u=eful whell the composition is employed
in cold climates. Similarly~, ethylene glycol, methanol, ethanol,
acetic acld, or similar organic compounds may be incorporated into
the compositions to improv= physical properties such as freezing
point, viscosity, and density, or to improve stability.
~ ~ A~ stated above, the micelle-forming amphipathic agents
which may be used in preparing the a~ueous solutions herein con-
templated may be either cation-active, anion-active, or of the
nonelectrolvtic type. Amphipathic agents generally have present
at least one xadical containing about 1~ 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
present compositions. The hydrophobic portions of these agents
may be aliphatic, alicyclic, alkylalicyclic, aromatic, arylalkyl,
or alkylaromatic. The preferred type of agents are those in which
- 13 -
28S4
the molecule contains a long, uninterrupted carbon chain contain-
ing from 10 to 22 carbon atoms in length. Examples of suitabls
anion-active amphipathic agents include the common soaps, as well
as materials such as sodium cetyl sulfate, ammonium lauryl sul-
fonate, ammonium di-Lsopropyl naphthalene sulfonate, sodium oleyl
glyceryl sulfate, mahogany and green sulfonates from petroleum or
petroleum fractions or extracts, sodium stearamidoethyl sulfonate,
dodecylbenzene sulfonate, dioctyl sodium sulfo-succinate, sodium
naphthenate, and the like. Other suitable sulfonates are dis-
closed 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 sul~onium 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 of polyethylene glyools.
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 of the above mentioned
types. Such compoun~s 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
described 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
8S~
of a hydrophobic hydrocarbon residue of comparatively low molecular
weight combined with a hydrophilic group of low molecular 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 chain structure, but no branch may have a length
of more than 7 carbon atoms from the point of attachment to the
hydrophilic residue, counting a benzene or cyclohexyl group as
beLng equivalent in length to an aliphatic chain of three carbon
atoms. Where the hydrocarbon residue consists of not more than 4
carbon atoms, structures of the normal primary alkyl type are pre-
ferred. 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 ox ethyl
groups.
This hydrophobic hydrocarbon residue is combined 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;
(c) A carboxy amide group;
(d) An amine salt groupt
(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 etherification,
esterification, or amidification, or the like, with another organic
residue which contains not more than four carbon atoms and also
~i2~35~
one or more of the hydrophilic groups named above, provided that
after said combination, at least one of the hydrophile groups
remains free. Specific examples illustrating this class of
compounds are: Ethyl alcohol, n-amyl alcohol, alphaterpineol,
p-cresol, cyclohexanol, n-butyraldehyde, benzaldehyde, n-butyric
acid, glycol mono-butyrate, propyl lactate, mono n-butyl amine
hydrochloride, n-propionamid, ethylene glycol mono n-butyl amine
hydrochloride, n-propionamid, ethylene glycol mono n-butyl ether,
pyridine, methylated pyridine, piperidine, or methylated piperidines.
The solubilizer (mutual solvent or hydrotropic compound
above described) is essentially a semi-polar liquid in the sense
that any liquid whose polar character is no greater than that of
ethyl alcohol a~d which shows at least some tendency to dissolve
in wa~er, or have water dissolved in itj is properly designated as
semi-polar.
The solubilizer or semi-po~ar li~uid indicated may be
illustrated by the formula X - Z, in which X is a radical having
2 to 12 carbon atoms, and which may be alkylt alicyclic, aromaticl
alkylalicyclic, alkylaryl, arylalkyl, or alicyclicalkyl in nature,
and may, furthermore, include heterocyclic compounds and substituted
heterocyclic compounds. ~here i5 the added limitation that the
longest 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 / U
- OH; - N ; -C ; - CN ; - COOH; or - OMe
\V O \V
where U and V are hydrogen or a hydrocarbon substituent and Me is
an alkalie metal;
N
0 if X is a cyclic teritary amine nucleus;
~z~s~ -
\
NH
if X is a cyclic secondary amine nucleus.
The semi-polar liquid also may be indicated by the
following formula: - X - Y - R - (Z)n Here X and Z have their
previous significance, R is ~ CH2 - , - C2H4 - , - C3H5 - ;
- C3H6- -or - C~H4 - O - C2H4 -
and n is either one or two as the choice of R demands. Y is
- one of the following:
O H H O O O
- ~ -N -; -N ~ C -O ; - O ~ O ; -S -.
In general, these hydrotropic agents are liquids having
di-electric constant values between about 6 and about 26, and have
at least one polar group containing one or more atoms of oxygen,
and/or nitrogen. It is signifioant, perhaps, that all of the
solubL1izers 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 am~hipathic agent
:
used~, he amount and kind of TFSA used, and the proportion ofwater used, and is best determined~by~preparing experimental
mixtures on a; small scale. ~ ~
In some casés, 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 so7utions
having greater stability 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.
;28S9L
The acylated polyether polyol or TFSA utilized in this
inven~ion is generally an organic polymer or semi-polymer with
an average molecular 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 subsequently to be desorbed at water~rock interfaces, the
TFSA must generally contain constituents which give it a highly
distributed hydrophile and hydrophobe character, and without such
concentrations of either hydrophilic or hydrophobic groups as to
produce water solubility or oil solubility, in the ordinary macro-
scopic 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 spreading
efficiently at such interfaces to form thin films 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, the present TFSA constituent o the micellar
solution in contrast to formerly used surfactants, has relatively
little or no tendency to stabilize either oil-in-water or water-
in-oil emulsions when present in normal use~amountsO
Usually the TFSA constituents applicable to the practice
of the invention are organic molPcules containing carbon, hydrogen
and oxygen, although in some instances 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 residues or otherwise. The critical requirements for
the TFSA compositions 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,
3Si4
carbonyl, ester, ether, sulfonium, amino, ammonium, phospho or
similar hydrogen bonding groups, connected by or to hydrophobic
groups, such as alkylene, alkyl, cycloalkyl, aryl, arylene,
aralkyl, polyalkylene, polyalkylyne, combinations of such groups
and such groups containing relatively non-polar substituents,
such as hydrocarbon, chlorine, fluorine and the like. Sometimes
the hydrophobic moieties 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 si~es depends greatly on the structure of the
hydrophilic moiety. Most commonly, the hydrophobi~ groups will
contain 14 to 22 carhon atoms and will have linear or sheet-like
conformations allowi~g for relatively flat orientation on surfaces.
Polar moieties other than hydrogen bonding ones are not
excluded from these compositions and, indeed, may be deliberately
included in some structures to improve adsorption and interacial
spreading tendencies. For example, quaternary ammonium groups,
while incapable of forming hydrogen bonds, c~an improve spreading
and interfacial adsorption in some applications by way of their
highly ionized form which imparts cationic character to the mole-
cules in which they occur and, via coulombic repulsion effects,
can improve spreading in a film.
Generally, the TFSA 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, the effective TFSA may be
derived from a wide variety of chemical reactants and may contain
numerous different groups or moieties, I have found that parti-
cularly effective products are those which are described as an
acylated polyether polyol having the formula:
S4
/ [O(A)jH]n
: R
~ R [(A)kH]J m
: wherein:
; A i~s an alkylene oxide group, -CiH2iO-;
O~is oxygen;
:is a positive integer no greater than about 10;
j is a positive integer no greater than about 100;
: k is a positive integer no greater than about 100;
:~ 10 N is nitrogen;
-
l is one of hydrogen, a monovalent hydrocarbon group containing
ess~than;about C~ or ~ H]; :
L iS a pos~itive integer~no greater than about:100;
: R is~a hydrocarbon moiety of a polyol,~a primarv 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 uni~y when R
~ is hydrogen, :; : ~ :
:~ 20 said~acylated polyether polyol~being the reaction product of said
polyether polyol and~a member selected ~rom the~alass consLsting~
of mono- and polybasic carboxylic acids, acid anhydrides, and
iso-, diiso-, and polyisocyanates, said:acylated polyether polyol
at about 25C (a) being less than about 1% by volume soluble~in
water and in isooctane; (b) having a solubility paramet~r in the
range of between about 6.9 and about 8.5; and (c) spreading at
the interface between distilled water and refined mineral oil to
form a film having a thickness no greater than about 20 Angstroms
at a film pressure of about 16 dynes per cm.
Alternatively, the TFSA constituents may be described as
acylated polyether polyols derivable by the reaction of an alkylene
~ LS;28S~ '
oxide containing less than about 10 carbon atoms with a member of
the group consisting of polyols, amines, polyamines and amino
alcohols containing from between about 2 to about 10 active
hydrogen groups capable of reaction with alkylene oxides and the
acylating agent being a member selected from the class consisting
of mono- and polybasic carboxylic acids, acid anhydrides and iso-,
diiso- and polyisocyanates.
Compositions incorporated within the scope of the formula
set forth above contain an average of about 1~ or more hydroxyl
groups per molecule and are generally composed of a cogeneric
mixture of products obtained by condensing alkylene oxides with
smaller molecules containing two or more reactive hydrogens as
part of hydroxyl or amino ~roups.
Representative of these compositions is polypropylene
- glycol, having an average molecular w~eight 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 addLtion of about six moLes of e~hylene oxide. Alternatively,
one may condense about 20 moles of propylene oxide with a pre-
viously prepared polyethylene glycol of about 240 average molecular
weight.
Alkylene ox-des suitable for use in preparing the TFSA
con~tituents used in the present solutions include ethylene oxide,
propylene oxide, butylene oxide, 2-3-epoxy-2-methyl butane, tri-
methylene oxide, tetrahydrofuran, glycidol, and similar oxides
containing less than about 10 carbon atoms. Because of their
reactivity and relatively low cost, the preferred alkylene oxides
for preparing effective TFSA constituents are the 1,2-alkylene
oxides (oxiranes) exemplified by ethylene oxide, propylene oxide
and butylene oxide. In the preparation of many TFSA constituents,
85~ -
more than one alkylene oxide may be employed either as mixtures
of oxides or sequentially to form block additions of individual
alkylene oxide groups.
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, resorcinol,
hydroquinone and the like.
Trihydric ether alcohois may be prapared 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, polvether
alcohols with a multiplicity of hydroxyl groups may be obtained
by condensing alkylene oxides with mu:Ltireactive starting compounds,
such as pentaerythritol,~ glycerol, N-monobutyl ethylene diamine,
txishydroxymethylaminomethane, ethylene diamine, diethylenetri-
amine, diglyoerol, hexamethylene diamine, decylamine and cyclo-
hexylamine. DeGroote, in U.S. Patent No. 2,679,511, describes a
number of amino deriyed 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
hydrogen compounds having 18 or fewer carbon atoms and 10 or
fewer reactive hydrogens.
Other general descriptions of suitable compounds coming
within the scope of the structure detailed above, along with
~ 5285~ '
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.
Effective TFSA with improved performance may be prepared
by acylation of the polyether polyol described above with a mono-
or polybasic carboxylic acid, acid anhydride, isocyanate, diiso-
cyanate or other polyisocyanate. An especially useful TFSA may
be made by reacting an approximately difunctional polyether polyol
with a difunctional carboxylylic acid, acid anhydride or iso-
cyanate to form a polymeric ester or urethane. However, poly-
merization is not always required, and where effected is usually
not carried to the point of including a very large number of
monomer units in the molecule. Frequently, effective reagents are
obtained where residual, unreacted hydroxyl or carboxyl groups
remain in the product or, where a polyisocyanate is used, one or
more residual isocyanate groups or am:ino or substituted urea groups
which result from reaction of residua:L end groups with water,
followed by decarboxylation, may remain.
Examples of acylating agents suitabIe for preparing useful
20~ esters include acetLc acid, acetic anhydride, butyric acid,
benzoic acid, abietic acid, adipic acld, diglycollic acid,
phthallic anhydride, fumaric acid, hydroxyacetic acid, itaconic
acid, succinic acid, dimerized fatty acids and the like. I have
found the most generally useful acylating agents to be the di-
and mono-basic acids and anhydrides containing less than 13 carbon
atoms.
Examples of isocyanates useful for the acylation of a
polyether polyol to produce an effective TFSA include methyliso-
cyanate, phenyl isocyanate, cyclohexylmethylene isocyanate, and the
like. Especially useful reactants are polyisocyanates containing
to or more isocyanate groups and including phenylene diisocyanate,
354
toluene diisocyanate, diphenylmethanediisocy~ate, hexa-
methylene diisocyanate, 1,5-Naphthalene diisocyanate and poly-
methylene polyphenyl isocyanates.
Following acylation reacti.ons of polyether polyols with
polyisocyanates, where a stoichiometric excess of the latter re-
actant is employed, remaining isocyanate groups may be left as
such or may, by appropriate addition of water or monohydric
alcohol, be converted to carbamic acid groups, which immediately
undergo decarboxylation to yield residual amino groups, or
carbamate groups.
Examples of acylated pol:yether polyols and their manufac-
turing procedures are well known to the art, as disclosed in
U.S. Patent No. 2,454,808, issued November 30, 1948, to
Kirkpatrick, U.S. Patent No. 2,562,878, issued August 7, 1951,
to Blair, U.S. Patent No. 2~679~511J issued May 25, 1954, to
DeGroote, U.S. Patent No. 2,60.2,061~ issued July 1, 1~52~, also
to DeGroote, "chemical Process Industries~l~by R.N. Shreve,
McGraw Hill Publishiny Co., 1967, page;654 et seq., and "Hlgh
:: : :
Polymers", Vol. XIII, edited by N.G. Gaylord, John Wiley & Sons,
:: 20 1963, page 317 et seq.
As to the limits of:the various constituents of the micel-
lar solutions containing TFSA, the following will serve as a
guide, the percentages being by weight:
Percent
TFSA Constituentsabout 5 to about 75
Hydrotropic Agentabout 2 to about 30
Amphipathic Agentabout 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,
- 24 -
~z~s~ .
may be due to the ability to bind water, i.e., to become hydrated.
This sugges~s that certain other materials which are highly hydro-
phile in character and cleaxly 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.
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 manufac~ure 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 somewhat 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 ef~ective 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
~0 situation, as follows:
A sample of fresh emulsion is obtained and lO0 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 to
other bottles 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.
8~4
After the shaking period, the bottles are placed upright
in the water hath and allowed to stand quietlyO Periodically,
the volume of the separated water layer is recorded along with
observations on the sharpness of the oil-water interface,
appearance of the oil and clarity of the water phase.
After ~he 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
samples of the oil are removed by pipette or syringe and centri-
fuged to determine the amount of free and emulsified water leftin 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 combinod information on residuaI water and emulsion,
speed of the water separation and interface appearance provides
the basis for selection of the generally most effective TFS~
: constituent, Where no~e of the results are satisfactory, the
tests should be repeated using higher concentrations of:TFSA
constLtuents and, conversely, where all results are good and
similar, the tests should be repeated at lower concentrations
until good discrimination is possible.
In practicing the process for resolving petroleum emul-
sions of the water-in-oil type with the present micellar solution,
such solution is brought into contact with or caused to act upon
the emulsion to be treated, in any of the various methods or
apparatus now generally used to resolve or blreak petroleum emulsions
with a chemical reagent, the above procedure being used alone or
in combination with other demulsifying procedure, such as the
electrical dehydration process.
One type of procedure is to accumulate a volume of
emulsified oil in a tank and conduct a batch treatment type of
859L
demulsification 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 solution, depending upon the convection currents in the
emulsion ~o produce satisfactory admixture. In a third modification
of this 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 adjustable proportioning mechanism or proportioning
pump. Ordinarily, the flow of fluids through the subsequent lines
: and fittings suEfices to produce the desired degree of mixing of
mlcellar TFSA solution and emulsion, although, in some instances,
additional mixing devices may be introduced into the flow system.
: 20 In this general procedure, the system may inolude various mechanical
devices for withdrawing free water, separating entrined water, or
accomplishing quiescent settling of the chemically tr~ated emulsionO
Heating devices may likewise be incorporated in any of the treating
procedures described~herein.
A third type of application (down-the-hole) of micellar
-TFSA solution to emulsion is 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 procedures.
This particular type of application is especially u~eful when the
8S4~
micellar solution is used in connection with acidification of
calcareous oil-bearing strata, especially if dissolved in the
acid employed for acidification.
In all cases, it will be apparent from the foregoing
description, the broad process consists simpl~ in introducing a
relatively small proportion of micellar TFSA solution into a
relatively large proportion of emulsion, admixing the chemical
and 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 water content
of the emulsion separates and settles from the mass.
Besides thelr util1ty for breaking petroleum emulsions,
~the present micellar TFSA solutions, as mentioned ea~lier, may be
;~ used to prevent emulsion formation in steam flooding, in secondary
waterflooding, in acidizing of oil-producing formationsj and the
ike.
Petroleum oils, even after demulsification, may contain
substantial amounts of inorganic salt~, ei~her in so1id form or as
sma11~rema1ning brine droplets. For this reason, most petroleum
; 20 oils~are desa1ted~prior to refining. The desalting step~is
effected by adding a~d mi~xing with~the oil a ~ew volume percentages
of fresh water to co~tact 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 desired, they may be added to the oil
phase as are present aromatic solvent compositions.
Most petroleum oil, along 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 mitigated or prevented by addition to the fluids of small
amounts of organic inhibitors. ~ffective 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 dimethyldodecyl ammonium chloride, hexadecylaminopropyl
amine, decyloxypropyl amine, mixed amines prepared by hydrogenation
of nitrile derivatives of tall oil fatty acids, soya acid esters
of~monoethanol amine, 2-undecyl, l~amino ethyl imidazoline and a
wlde variety of caticnic nltrogen compounds of semi-polar character.
Also effective in some applications are nonyl succinic acld, dio-
cylnaphthalene suIfonic acid, trimeric and dimeric fatty acids,
propargyl alcohol, mercaptobenzothiozole, 2, 4, 6-trimethyl-1, 3,
5-trithiaane, hexadecyldimethyl benzimidazolium bromide, 2-thio-
butyl-N-tetrodecylpyridinium 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 prevent or lessen con~act of corrosive
fluids and gases with the metal and interfere with ionic and
electron transfer reactions involved in the corrosion process.
Corrosion inhibitors are quike 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 at~ack
occurs at the surface, the inhibitor may be introduced at or near
the well head, allowing it to adsorb on the flow lines and surface
equipment to insure protection.
Addition of inhibitor at either downhole or surface
locations may be combined conveniently 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 amphlpathic agents whi¢h might be otherwise
utilized. Combining the micellar solution with corrosion inhibitor
permits more economic chemical treatment by reducing inventory to
one compoundj requiring only one chemical injection system rather
than two and lessening the labor and supervision required.
Still another important effec~ of using the micellar
solution of TFSA and corrosion inhibitor results from the prevention
of emulsification by the inhibitorO 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
nonemulsifving hydrocarbons such as distillate, casing head
gasoline, kerosene, diesel fuel and various refinery fractions.
ii4
Inhibitors are commonly used in refinery systems where emulsifi-
cation is highly objectionable and where the compositions could
be designed to include an effective emulsion preventative micellar
solution of TFSA.
Inhibitor use may range ~rom 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,
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 ~f 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
mhibitor in water dispersible, micellar solutions are given below.
Selection of the proper corrosion inhibltor for a given
system or oil is usually made by conducting laboratory tests
under conditions simulating those encountered in the well or
flowline. Such tests are exemplified by that described in Item
No. lK155, "~roposed~Standardized Laboratory Procedure for
Screening Corrosion Inhibitors for Oil and Gas Wells", published
by the National Association of Corrosion Engineers, Houston, Texas.
EXAMPLES OF THIN FILM SPREADING AGENTS
EXAMP~E I
Reference is made to U.S. Patent No. 2,562,878, dated August
7, 1951, to Chas. M. Blair, Jr., which describes the preparation
of demulsifiers which are polyesters of dicarboxylic acids and
polyhydric alkylene ether glycols. Using the procedure described
therein, 150 1bs. of diglycolic acid was reacted with'2,000 lbs.
of "Pluronic L-62" manufactured by Wyandotte Chemical Corporation
of Wyandotte, Michigan. "Pluronic L-62"~is described as a poly-
propylene glycol havlng a molecular weight of about 1,650 to
which has been added and condensed therewith about 25% by weight
of ethylene oxide.
The esterification reaction was continued until the acid
number of the reaction mixture had dropped to about 15.
The resulting product' was a moderately viscous liquid,
:
insoluble to the extent of 1% in either water or isooctane, had a
Solubility Parameter of 8.1, and s~read at the interface between
white mineral oll and water at 25C to yield a fllm pressure of
22 dynes per c~ at a calculated thickness of 14 Angstroms.
:
EXAMPLE 'II
' Using the procedure des'cribèd by C. H. M. Roberts in U.S.
Patent No. 1,977,146, dated October 23, 1934, one mole'each`of
the mono- and diglycerides' of ricinoleic acid were'reacted with
three moles of phthallic anhydride. ~he'reaction was stopped
short of gelation to yield a viscous, reddish polymer, insoluble
in water and isooctane, having a solubility parameter of 8.4 and
spreading at the white oil-dis~illed water interface with a
pressure of 20 dynes per cm at a calculated thickness of 10
Angstro~s.
EXAMPLE III
To l,000'parts of commercial polyoxypropylene'glycol of
molecular weIght of about 2,000 was added 200 parts of ethylene
* Trade Mark
32 -
854
l oxide. Reaction was conducted as in Example I. After completion
of the ethylene oxide addition, a mild vacuum was applied for 30
minutes to remove any unreacted oxide. The temperature was
lowered to 40C and 5 parts of dodecylbenzene~'sulfonic 'acid were
added to the reaction mass while'stirring. Eighty parts of
phenyacetic acid were then introduced and heating and stirring
were commenced under a take-'off condensor. The temperature'was
slowly ra1sed to about 160C over a three-hour period and was
held at this temperature ~for an additional 2 hours.
The'product was then cooled and drummed. It was an effec-
tive'demulsifier espec'ially for pet'roleum emulsions encountered
in southern Louis1ana, and met the'cr1teria recited previously
for such interfacially active'compounds.
::
:`::: :: ::
FX~MPLE IV
Two and one-~hal parts of tris-hydroxymethylaminomethane
were substituted for the dipropylene glyco1 in Example I of~my
co-pendin~ application Serial No.' _ 6 , ~ , , fL1ed
, entltled "Petroleum De~ulsifier's Comprising A
Polyether Polyol". ~ ,;
To the above~product was added with stirr1ng 5~parts of
maleic anhydride. The temperature was then raised to 130C
while the vessel was open to a take-off condensor. St'irring and
heating were continued unt1l a sample of the react1on mass had a
viscosity in the range of 900 to l,lO0 centipoises at 80C.
This product was an effective thin film spreading agent and
especially useful as a dem,ulsifier for petroleum emulsions
occurring in western Kansas and in Kuwait.
.
~;2~35~
EX~MPLF V
Using the apparatus and procedure of Example I, 4,000
lbs. of polypropylene glycol of average molecular weight l,200
was condensed with 700 lbs. of ethylene oxide. Forty pounds of
potassium hydroxide was dissolved in the polypropylene glycol
prior to oxide addition, which was carried out within the tempera-
ture range of about 140 - 160C. under a maximum pressure of
about 75 psi.
After completion of the above reaction, the temperature
was lowered to about 60C and the reaction vessel was connected
to a take-off condensor. Fifty pounds of 85~ phosphoric acid was
slowly added to the reaction mass with stirring~followed by 314
; lbso of adipic acid. The temperature was then slowly brought to
145 - 155C. while continuing to stir and to distill water from
the reaction mixture. The acid number of the produot was periodi-
cally determined. When a valve between 10 and 15 mg. KOH per gm.
was reached, heating was stopped, the product was cooled to room
temperature and filled into 55-gallon drums.
This product has a calculated equivalent weight in excess
of 4,000, is insoluble to the extent of 1% in water and isooctane,
;; : :
has a solubility parameter of 7.9 and rapidly spreads at the inter-
face between white oil and distilled water, at 25C, to give a film
pressure of 18 dynes~per cm at a calculated thickness of 18
Angstroms.
EXAMP_E VI
Into a l,000 gal. stainless steel autoclave, equipped with
steam jacket, internal cooling coils, stirrer, condensor and
several inlet feed lines were place 92 lbs. of glycerol. 2,750 lbs.
of a mixture of 2,250 lbs. of propylene oxide and 500 lbs. of
ethylene oxide was prepared in a separate weighed feed tank.
i;2~3~4
Twelve pounds of a 50% aqueous solution of potassium hydroxide
was stirred into the glycerol while heating to about 120C.
During this period, the vessel was connected to a steam jet
vacuum system through the condensor, arranged in take-off position.
Stirring under vacuum was continued until the evolution of water
had effectively ceased.
The vessel was then closed and the mixed oxides were
introduced slowly. The resulting exothermLc reaction was con-
trolled by the oxide addition rate such as to allow a slow
increase in temperature to about 150C. After the addition of
:`
about 800 lbs. of oxides the rate of reaction declined. The oxide
addition line was then closed, the temperature lowered to 110C,
the vessel was vented briefly to the vacuum jet, and an additional
25 lbs. of 50% aqueous solution of potassium hydroxide was intro-
duced into the reaction mass which was then stirred under vacuum
at 120 - 140C until water evolution ceased.
The vessel was closed, the oxide inlet line was again
opened and reaction was~continued with the fresh catalyst~ holding
-~ ~ the temperature at about 150C under a maximum pressure of about
~:: ? ~ 50 psi until the whole of the ~,750 lbs. of mixed oxide had been
reacted
~ After cooling this batch to about 120C, 1,860 lbs. of
commercial mixed xylene was pumped into the autoclave and the whole
was stirred and adjusted to a temperature o about 95C. A solu-
tion of 125 lbs. of toluene diisocyanate in 200 lbs. o xylene was
then slowly pumped into the vessel while maintaining the tempexa-
ture at 100 ~ 5C~ for approximately the two hours required for
the addition. The temperature was then raised to 140C and
stirring was continued until the viscosity at 100C was within
the range of 1,000 to 1,500 centipoises. Heating was then dis-
continued and the batch was cooled quickly to allow transfer to
storage.
85~
A sample of this product, after removal of xylene by vacuum
distillation was found to meet the three criteria ~or a TFSA.
EXAMPLES OF MICELLAR SOLUTIONS OF TFSA's
_ . . .......... .
EXAMPLE A
Wt. %
Product o Example II 40
2-heptadecyl-3-triethylene triaminoimidazoline 6
Acetic Acid 1.5
Phenol 2.5
; 10 n-Butanol 10
Water 40
Besides having good demulsification action, this product
:: :
is an effective corrosion in~ibitor for down-the-hole use, the
imidazoline used as the amphipathic agent being a strongly ad~
sorbed inhibitor for steel ln anaerobic systems.
EXAMPLE B
Wt.
i ~ ~
Product of Example IV 20
n-DodeGylbenzene sulfonic acid 6
20 Methanol 14
Ethylene glycol monobutyl ether 10
Water 50
This clear,~homogeneous solution is quite acidic. It
can be combined with 15~ hydrochloric acid used for acidizing
calcareous oil-producing formations and acts therein to prevent
emulsification of acid and &pent acid.
EXAMPLE C
Wt. %
Product of E~ample II 70
Oleyl amine 10
359~ .
Acetic Acid 3
n-Propanol 2
Water lS
This is a clear, homogeneous but viscous solution.
EXAMPLE D
Wt. %
Product of Example III 35
Dinonylphenolsulfonic acid
50% aqueous UaOH 2
10 : Isopropanol ~ 9~
Methanol 10 :
;~ Water ~ ~ 36
: EXAMPLE E
-
: Wt. %
~ Product of Example I 28
: Ethyleneglycol monobutyl ether 14
5-mole ethylene adduct of p-nonyI phenol 14
: Water 44
This product may be diluted further with water to form
~20 clear to slightly opalescent solutions.
E XAMPLE F
Wt. %
Product of Example VI 41.0
Ammonium dodecylbenzene sul~onate 17.5
Isopropanol 24.0
Water 17.5
This product is an effective micellar composition for
numerous petroleum emulsions, but is especially effective as a
. component in
~Z85~1~
synergistic blends with the composition of Examble B and with
other compositions such as those disclosed in my co-pending
applications cited in detail, above.
The product of Example F has also been found to be an effec-
tive waterflood additive, especially in combination with aqueous
micellar solutions of resinous polyoxide adducts such as those
,
described in ~y co-pending Canadia-n application, Serial
No. 361,787 filed October 8, 1980, and entitled, "Micellar Solu-
tions Of Thin Film Spreading Agents Comprising Resinous Poly-
alkylene Oxide Adducts".
EXAMPLE G
Wt.
Product of Example IV 35
:
Oc-taethyleneglycol Monooleate l0
Ethylene glycol ~monobutyl ether 12
:
"Polyox" coagulant grade (a commercial
polyethylene oxide~ of about
5 million molecular~weight~ 2
Wàter 41
:
This~product is a very viscous, redish liquid, readily dis-
~20 persible in water to~form s11ght1y opalescent solutions. It iseffective alone or in combination with other aqueous systems or
diluted in water~as a flooding agent for oi] recovery, especial-
ly where a higher viscosity agent is needed for mobility control.
Further, it is an effective demulsifier for heavy oil emul-
sion produced in the McKittrick, Ca. field and is even more
effective in a 50-50 blend with the compositon of Example E.
Still further, this product is found to assist in the floc-
culation and sedimentation of finely ground hematite particles
during the decantation of aqueous slurries of the
ground ore to remove sand and clay minerals and effect benefic-
iation of the iron-containing values.
- 38 -
s~ ~
Among procedures which have been found useful in selecting
effective mîcellar TFSA solutions for this use, one involves a
determination of oil displacement efficiency from prepared oil-
containing rock cores in equipment described below. A tube of
glass or transparent polymethacrylate ester, having an inside
diameter of about 3.5 cm (1~ in.) and a length of about 45 cm
(18 in.), is fitted with inlet connections and appropriate valves
at each end. rrhe tube is mounted vertically on a rack in an air
bath equipped with a fan, heater and thermostat which allows
selection and maintenance of temperatures in the range of between
about 25 - 130C.
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 wi~h toluene to
remove oil, is dried and is then ground in a ball mill to the
point where a large percentage 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 calibra-
tions and is referred to as the "pore volume", being that volume ofwater just sufficient to fill the pores or interstices of the
packed plug rock.
35i4
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 dis-
placement 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-
minea from the reservoir readings. This is referred to as the
volume of oil in place. The tube;of sand containing oil is then
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 equilib~ium may be varied widely. At higher
temperatures, the time required to reach equilibrium is probably
reduced. Usually, for comparative test~, three days are allowed
to age the oiI-rock plug.~ Results wlth this procedure closely
~ simulate work with actual cores o~ oil-bearing rock.
The oil and water samples used for ~est purposes are pre-
ferably taken under an inert gas such as high purity nitrogen, and
are maintained out of contact with air duriny all miniuplations in
order to prevent o~idation of the oil and concomitant introduction
of spurious polar, surface-active constituents in the oil. At
this point, the rock-oil system simulates the original oil forma-
tion before primary production oil has commenced and well before
any secondary waterflood operation.
The upper inlet line to the tube 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 into the sand body from
~ i2~
the top to displace fluids out of the bottom tubiny connection
into a calibrated 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. This formation 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 mi~ellar :~FSA 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 displacemen 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
injected, 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.
8~ -
Generally, six ox 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 conc~ntrations, simu~taneously with three blank tests run
similarly but without addition of micellar TFSA solution to the
water.
The composition of Example D was tested by this procedure
with the following conditions:
Oil -- Ranger Zone, Wilmington, Calif.,
field API Gravity approximately 13.5
Water -- Mixed water used in ~lood operations
Airbath Temperature -- 150F (Same as formation temperature)
Oil was displaced by pumping two pore volumes of water into
the sand. After measuring the volumes of oil and water produced
through the bottom line, a further 0.2 pore volumes of water con-
tainlng 2,600 ppm o~ the composition of Example F was injected
followed by 2.8 volumes of water containing 175 ppm of the composi-
:
tion of Example D. Measurement of the volumes of oil and water
produced were read after each 0.2 pore volumes of water was injected.
Results of this test at the points of 2,3 and 5 pore volumes
of injected water are gi~en in the table below wherein averages of
three duplicate determinations are presented.
Oil Recovery as ~ of
Oil in Place
. _ , ,, _ .
Composition of Ratio of Increment
Example F of Oil Production
Added to Water After Initial 2
Pore Volumes (P.V.)No Chemical after Initial P.V. Chemical/
of Water Injected Addition 2 P.V. o-f Water No Chemical
_ . , , , _ . .
2 36.5 36.5
3 40.0 43.7 2.1
5 43.1 53.0 2.5
~i;213S4
Use of the composition of Example F in the amounts given
above resulted in the production of 110% more oil from injection
of one incremental pore volume of water than was produced by water
injection alone and gave 150% 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.
: .
