U.S. patent application number 17/324507 was filed with the patent office on 2021-11-04 for methods and compositions for stimulating the production of hydrocarbons from subterranean formations.
This patent application is currently assigned to Flotek Chemistry, LLC. The applicant listed for this patent is Flotek Chemistry, LLC. Invention is credited to Paul Ashcraft, Lakia M. Champagne, Natalie Forbes, Angus Fursdon-Welsh, Randal M. Hill.
Application Number | 20210340435 17/324507 |
Document ID | / |
Family ID | 1000005712224 |
Filed Date | 2021-11-04 |
United States Patent
Application |
20210340435 |
Kind Code |
A1 |
Hill; Randal M. ; et
al. |
November 4, 2021 |
METHODS AND COMPOSITIONS FOR STIMULATING THE PRODUCTION OF
HYDROCARBONS FROM SUBTERRANEAN FORMATIONS
Abstract
Emulsion or microemulsion for treating an oil or gas well having
a wellbore are provided, and related methods. In some embodiments,
the emulsion or microemulsion comprises an aqueous phase; a
surfactant; and a non-aqueous phase comprising a first type of
solvent and a second type of solvent. In some embodiments, the
first type of solvent is a long chain hydrocarbon. In some
embodiments, the second type of solvent is an oxygenated solvent.
The emulsion or microemulsion may comprise additional components
(e.g., at least one type of co-solvent).
Inventors: |
Hill; Randal M.; (The
Woodlands, TX) ; Ashcraft; Paul; (Cypress, TX)
; Fursdon-Welsh; Angus; (Spring, TX) ; Champagne;
Lakia M.; (The Woodlands, TX) ; Forbes; Natalie;
(Houston, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Flotek Chemistry, LLC |
Houston |
TX |
US |
|
|
Assignee: |
Flotek Chemistry, LLC
Houston
TX
|
Family ID: |
1000005712224 |
Appl. No.: |
17/324507 |
Filed: |
May 19, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
16206304 |
Nov 30, 2018 |
11053433 |
|
|
17324507 |
|
|
|
|
62593680 |
Dec 1, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C09K 8/602 20130101;
C09K 8/86 20130101 |
International
Class: |
C09K 8/86 20060101
C09K008/86; C09K 8/60 20060101 C09K008/60 |
Claims
1. A microemulsion for treating an oil or gas well having a
wellbore, comprising: a surfactant comprising a nonionic
surfactant; an aqueous phase; and a non-aqueous phase comprising a
first type of solvent and a second type of solvent, wherein the
first type of solvent is a long chain hydrocarbon solvent, and the
second type of solvent is an oxygenated solvent; wherein the second
type of solvent is present in an amount of about 1 wt % to about 15
wt % versus the total microemulsion.
2. The microemulsion of claim 1, further comprising a terpene.
3. The microemulsion of claim 2, wherein the terpene comprises
d-limonene and/or dipentene.
4. The microemulsion of claim 1, wherein the nonionic surfactant
comprises an alcohol ethoxylate containing a hydrocarbon group of
10 to 18 carbon atoms and an ethoxylate group of 5 to 12 ethylene
oxide units.
5. The microemulsion of claim 1, wherein the surfactant comprises
the nonionic surfactant and an alcohol ethoxylate.
6. The microemulsion of claim 5, wherein the alcohol ethoxylate
comprises ethoxylated tristyrylphenol.
7. The microemulsion of claim 1, wherein the oxygenated solvent
comprises a cyclic or acyclic, branched or unbranched alkane having
6 to 12 carbons and substituted with a hydroxyl group.
8. The microemulsion of claim 1, wherein the oxygenated solvent
comprises isomers of heptanol, isomers of octanol, isomers of
nonanol, isomers of decanol, isomers of undecanol, and/or isomers
of dodecanol.
9. The microemulsion of claim 1, wherein the oxygenated solvent
comprises octanol or an isomer thereof.
10. The microemulsion of claim 1, wherein the oxygenated solvent
comprises isooctanol.
11. The microemulsion of claim 1, further comprising a terpene, a
first co-solvent, and a second co-solvent, wherein the terpene
comprises d-limonene and/or dipentene, the first co-solvent
comprises isopropanol, and the second co-solvent comprises
propylene glycol.
12. The microemulsion of claim 11, wherein the oxygenated solvent
comprises isooctanol and is present in an amount of about 1 wt % to
about 3 wt % versus the total microemulsion.
13. The microemulsion of claim 12, wherein: the surfactant
comprises the nonionic surfactant and an alcohol ethoxylate; the
alcohol ethoxylate comprises ethoxylated tristyrylphenol; and the
nonionic surfactant comprises an alcohol ethoxylate containing a
hydrocarbon group of 10 to 18 carbon atoms and an ethoxylate group
of 5 to 12 ethylene oxide units.
14. The microemulsion of claim 1, wherein: the first type of
solvent is present in an amount of about 1 wt % to about 20 wt %
versus the total microemulsion; the aqueous phase is present in an
amount of about 5 wt % to about 75 wt % versus the total
microemulsion; the surfactant is present in an amount of about 5 wt
% to about 40 wt % versus the total microemulsion; the
microemulsion comprises from about 1 wt % and about 5 wt % of a
first type of co-solvent, versus the total microemulsion; the
microemulsion comprises from about 15 wt % to about 25% of a second
type of co-solvent, versus the total microemulsion.
15. The microemulsion of claim 1, wherein the first type of solvent
comprises a C.sub.12-22 hydrocarbon compound, a plurality of
C.sub.12-22 hydrocarbon compounds, a C.sub.12-18 alpha-olefin
solvent, a plurality of C.sub.12-18 alpha-olefin solvents, and/or a
C.sub.12-18 hydrocarbon solvent.
16. The microemulsion of claim 1, wherein the microemulsion further
comprises at least one co-solvent.
17. The microemulsion of claim 16, wherein the at least one
co-solvent comprises a C.sub.1-6 alcohol and/or a C.sub.1-7
alkylene glycol.
18. The microemulsion of claim 16, wherein the at least one
co-solvent comprises isopropanol and/or propylene glycol.
19. The microemulsion of claim 1, wherein the ratio of the first
type of solvent to the second type of solvent is between about 11:4
to about 1:1 or between about 5:1 to about 1:5 by weight.
20. The microemulsion of claim 1, wherein the second type of
solvent is isooctanol and is present in an amount of about 1 wt %
to about 3 wt % versus the total microemulsion.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 16/206,304, filed Nov. 30, 2018, which claims
priority to U.S. Provisional Patent Application Ser. No.
62/593,680, filed on Dec. 1, 2017, which are incorporated herein by
reference in their entireties.
FIELD OF INVENTION
[0002] The present invention generally provides methods and
compositions for stimulating the production of hydrocarbons (e.g.,
formation crude oil and/or formation gas) from subterranean
formations.
BACKGROUND OF INVENTION
[0003] Emulsions and/or microemulsions are commonly employed in a
variety of operations related to the extraction of hydrocarbons,
such as well stimulation. Subterranean formations are often
stimulated to improve recovery of hydrocarbons. Common stimulation
techniques include hydraulic fracturing. Hydraulic fracturing
consists of the high pressure injection of a fluid containing
suspended proppant into the wellbore in order to create fractures
in the rock formation and facilitate production from low
permeability zones. All chemicals pumped downhole in an oil and/or
gas well can filter through the reservoir rock and block pore
throats with the possibility of creating formation damage. It is
well known that fluid invasion can significantly reduce hydrocarbon
production from a well. In order to reduce fluid invasion,
emulsions or microemulsions are generally added to the
well-treatment fluids to help unload the residual aqueous treatment
from the formation.
[0004] Accordingly, although a number of emulsions or
microemulsions are known in the art, there is a continued need for
more effective emulsions or microemulsions for use in treatment of
an oil and/or gas well.
SUMMARY OF INVENTION
[0005] Generally, compositions for use in various aspects of the
life cycle of an oil and/or gas well, and related methods, are
provided.
[0006] In some embodiments, microemulsions for treating an oil or
gas well having a wellbore are provided comprising a surfactant; an
aqueous phase; and a non-aqueous phase comprising a first type of
solvent and a second type of solvent, wherein the first type of
solvent is a long chain hydrocarbon solvent, and the second type of
solvent is an oxygenated solvent.
[0007] In some embodiments, methods of treating an oil or gas well
having a wellbore are provided comprising injecting an emulsion or
microemulsion into the wellbore of the oil or gas well to stimulate
the production of hydrocarbons, wherein the emulsion or
microemulsion comprises a surfactant, an aqueous phase, and a
non-aqueous phase comprising a first type of solvent and a second
type of solvent, wherein the first type of solvent is a long chain
hydrocarbon solvent, and the second type of solvent is an
oxygenated solvent.
[0008] Other aspects, embodiments, and features of the methods and
compositions will become apparent from the following detailed
description when considered in conjunction with the accompanying
drawings. All patent applications and patents incorporated herein
by reference are incorporated by reference in their entirety. In
case of conflict, the present specification, including definitions,
will control.
DETAILED DESCRIPTION
[0009] Compositions for use in various aspects of the life cycle of
an oil and/or gas well, and related methods, are provided. In some
embodiments, the composition is provided as an emulsion or a
microemulsion, wherein the emulsion or microemulsion comprises an
aqueous phase, a surfactant, and a non-aqueous phase. In some
embodiments, the non-aqueous phase comprises a plurality of types
of solvents. In some embodiments, the compositions are used in
methods relating to treating an oil and/or gas well having a
wellbore.
[0010] In some embodiments, the emulsion or microemulsion comprises
at least two types of solvents (e.g., a first type of solvent and a
second type of solvent). In some embodiments, the first type of
solvent is a long chain hydrocarbon solvent. In some embodiments,
the second type of solvent is an oxygenated solvent. Without
wishing to be bound by theory, the inventors unexpectedly
discovered that the ratio of the first type of solvent to the
second type of solvent may affect the ability to form a stable
emulsion or microemulsion with the selected solvents. For example,
in embodiments wherein only the first type of solvent or only the
second type of solvent is present in a composition, a stable
emulsion or microemulsion may not form, whereas a stable emulsion
or microemulsion can form under essentially the same conditions
(e.g., temperature, pressure) wherein both the first type of
solvent and the second type of solvent are present in a selected
ratio (e.g., at the same total weight percent). For example, see
Example 1 wherein a stable microemulsion does not form when only
the aliphatic mineral spirit is present in the composition, but
does form when isooctanol is included in specific ratios. In some
embodiments, the first type of solvent (e.g., long chain
hydrocarbon solvent) and the second type of solvent (e.g.,
oxygenated solvent) may be provided in a ratio between about 11:4
to about 1:1, or between about 5:1 to about 1:5, or between about
4:1 to about 1:1, or between about 6:1 to about 1:1, by weight of
the first type of solvent to the second type of solvent.
[0011] In some embodiments, the emulsions or microemulsions
described herein are stable over a wide range of temperatures. In
some embodiments, the emulsion or microemulsion is stable at
temperatures greater than about -25.degree. C., or greater than
about -20.degree. C., or greater than about -15.degree. C., or
greater than about -10.degree. C., or greater than about -5.degree.
C., or greater than about 0.degree. C. In some embodiments, the
emulsion or microemulsion is stable at temperatures up to about
25.degree. C., or up to about 30.degree. C., or up to about
40.degree. C., or up to about 50.degree. C., or up to about
55.degree. C., or up to about 60.degree. C., or up to about
70.degree. C. Combinations of these above mentioned ranges are
possible, for example, the microemulsion is stable for temperatures
between about -10.degree. C. and about 55.degree. C. Those of
ordinary skill in the art will be aware of methods for determining
the stability of an emulsion or microemulsion over a range of
temperatures, for example mixing a sample of surfactant, solvent,
and water in a container (e.g., having a volume between 10 and 50
milliliters), applying a low amount of shear (e.g., by hand with a
gentle rocking motion back and forth), and placing the sealed glass
jar at a fixed temperature (e.g., in a cold bath or oven at a fixed
temperature depending upon whether low temperature or high
temperature stability are preferentially investigated,
respectively). Samples can be observed over time (e.g., once an
hour) to determine visually if the microemulsion is becoming
destabilized, for example, as indicate by the formation of a hazy
coacervate, precipitate, or flocculation within the sample jar.
[0012] Without wishing to be bound by theory, the emulsions and
microemulsions described herein may provide a combination of
desired features for use in oil and/or gas well application. For
example, the presence of one or more long chain hydrocarbon
solvents may provide a solvency that is not observed when using
shorter chain hydrocarbon solvents. Furthermore, the emulsions or
microemulsions described herein may provide an increased surface
activity as compared to similar emulsions or microemulsions not
including the described combination of solvents.
[0013] Additional details regarding the emulsions or
microemulsions, as well as the components of the emulsions and
microemulsions and applications of the emulsions or microemulsions,
are described herein. The terms emulsions and microemulsions should
be understood to include emulsions or microemulsions that have a
water continuous phase, or that have an oil continuous phase, or
microemulsions that are bicontinuous or multiple continuous phases
of water and oil. In some embodiments, the emulsion or
microemulsion has a water continuous phase. It should be understand
that while many of the embodiments described herein refer to
microemulsions, this is by no means limiting, and emulsions may
also be encompassed.
[0014] The emulsion or microemulsion generally comprises a
non-aqueous phase. In some embodiments, the non-aqueous phase
comprises a solvent blend, comprising at least two types of
solvents. For example, the solvent blend may comprise a first type
of solvent and a second type of solvent. As described herein, in
some embodiments, the first type of solvent is a long chain
hydrocarbon solvent and/or the second type of solvent is an
oxygenated solvent.
[0015] In some embodiments, the emulsion or microemulsion comprises
from about 1 wt % to about 30 wt %, or from about 2 wt % to about
25 wt %, or from about 5 wt % to about 25 wt %, or from about 15 wt
% to about 25 wt %, or from about 3 wt % to about 40 wt %, or from
about 5 wt % to about 30 wt %, or from about 7 wt % to about 22 wt
% of the total amount of the one or more types of solvent, versus
the total weight of the emulsion or microemulsion composition.
[0016] In some embodiments, each solvent type may comprise more
than one solvent of that type. For example, the first type of
solvent may include a single long chain hydrocarbon solvent or a
plurality of types of long chain hydrocarbon solvents. As another
non-limiting example, the second type of solvent may include a
single oxygenated solvent or a plurality of types of oxygenated
solvents. In some embodiments, a solvent is a liquid that dissolves
other substances, for example, residues or other substances found
at or in a wellbore (e.g. kerogens, asphaltenes, paraffins, organic
scale).
Long-Chain Hydrocarbon Solvents
[0017] In some embodiments, the first type of solvent is a long
chain hydrocarbon solvent or comprises a plurality of types of long
chain hydrocarbon solvents. The term hydrocarbon solvent
encompasses unsubstituted cyclic or acyclic, branched or
unbranched, saturated or unsaturated, hydrocarbon compounds (e.g.,
alkanes, alkenes) The term long chain encompasses solvent having a
high number of carbon atoms, for example, 12-22, or 12-20, or
12-18, or 14-24, or 14-22, or 14-20, or 13-23, or 11-14, carbon
atoms, inclusive.
[0018] In some embodiments, the first type of solvent is or
comprises a mixture of C.sub.12-22 hydrocarbon solvents, or a
mixture of C.sub.12-20 hydrocarbon solvents, or a mixture of
C.sub.12-18 hydrocarbon solvents, or a mixture of C.sub.14-24
hydrocarbon solvents, or a mixture of C.sub.14-22 hydrocarbon
solvents, or a mixture of C.sub.14-20 hydrocarbon solvents, or a
mixture of C.sub.13-23 hydrocarbon solvents, or a mixture of
C.sub.11-14 hydrocarbon solvents. In some embodiments, the
hydrocarbon solvents are unsubstituted cyclic or acyclic, branched
or unbranched alkanes. In some embodiments, the hydrocarbon
solvents are unsubstituted cyclic or acyclic, branched or
unbranched alkenes. In some embodiments, the hydrocarbon solvents
include a combination of unsubstituted cyclic or acyclic, branched
or unbranched alkanes and unsubstituted cyclic or acyclic, branched
or unbranched alkenes.
[0019] In some embodiments, the first type of solvent is an
aliphatic mineral spirit, which is given its ordinary meaning in
the art and refers to a solvent comprising a plurality of types of
long chain hydrocarbon solvents, generally alkanes. The aliphatic
mineral spirit may be purchased from a commercial source.
Non-limiting examples of aliphatic mineral spirits that may be
purchased include EFC Crystal 210 solvent (available from Total),
Shellsol D80 (available from Shell.RTM.), and Exxsol.TM. D80
(available from Exxon Mobil.RTM.). In some embodiments, the
aliphatic mineral spirit has a high boiling point (e.g., greater
than about 150.degree. C., or greater than about 180.degree. C., or
greater than about 200.degree. C.) and/or a low vapor pressure
(e.g., less than about 1 kPa). As will be known to those of
ordinary skill in the art, aliphatic mineral spirits may comprise a
small amount of impurities (e.g., aromatic compounds) due to the
manner in which they are prepared (e.g., hydrogenation of petroleum
fractions). In some embodiments, the aliphatic mineral spirit
comprises less than about 2%, or less than about 1%, or less than
about 0.5%, or less than about 0.1%, or less than about 0.05%,
impurities (e.g., aromatic compounds).
[0020] In some embodiments, the first type of solvent is a long
chain alpha-olefin solvent or comprises a mixture of long chain
alpha-olefin solvents. Alpha-olefins (or .alpha.-olefins) are a
family of organic compounds which are alkenes (also known as
olefins) with a chemical formula C.sub.xH.sub.2x, distinguished by
having a double bond at the primary or alpha (.alpha.) position. In
some embodiments, x is 12-22, or 12-20, or 12-18, or 14-24, or
14-22, or 14-20, or 13-23, or 11-14. In some embodiments, the first
type of solvent is a C.sub.12-18 alpha-olefin solvent or comprises
more than one type of C.sub.12-18 alpha-olefin solvents.
Non-limiting examples of C.sub.12-18 alpha-olefin solvents include
1-dodecene, 2-methyl-1-undecene, 1-tridecene, 2-methyl-1-dodecene,
1-tetradecene, 2-methyl-1-tridecene, 1-pentadecene,
2-methyl-1-tetradecene, 1-hexadecene, 2-methyl-1-pentadecene,
1-heptadecene, 2-methyl-1-hexadecene, 1-octadecene, and
2-methyl-1-heptadecene.
[0021] In some embodiments, the first type of solvent (e.g., long
chain hydrocarbon solvent) is present in an amount from about 1 wt
% to about 25 wt %, or about 1 wt % to about 20 wt %, or from about
1 wt % to about 15 wt %, or from about 1 wt % to about 10 wt %, or
from about 1 wt % and about 5 wt %, or from about 1 wt % and about
3 wt %, versus the total microemulsion.
Oxygenated Solvents
[0022] In some embodiments, the second type of solvent comprises an
oxygenated solvent. As used herein, the term oxygenated solvent is
given its ordinary meaning in the art and refers to solvents
comprising one or more oxygen atoms in their molecular structure in
addition to carbon atoms and hydrogen (e.g., an oxygenated
hydrocarbon solvent). For example, the solvent may comprise one or
more of an alcohol, an aldehyde, a ketone, an ester, or an ether.
In some embodiments, the oxygenated solvent comprises a plurality
of types of oxygenated solvents having 6-22 carbon atoms, or 6-18
carbon atoms, or 8-18 carbon atoms, or 12-18 carbon atoms.
Non-limiting examples of oxygenated solvents include oxygenated
terpenes, alcohols, ketones, aldehydes, and esters.
[0023] In some embodiments, the ketone is a ketone having 12-18
carbon atoms. In some embodiments, the aldehyde is an aldehyde
having 12-18 carbon atoms. In some embodiments, the ester is an
ester having 6-22 carbon atoms. In some embodiments, the ester is a
methyl ester having 6-22 carbon atoms. In some embodiments, the
ester is an alkyl aliphatic carboxylic acid ester.
[0024] In some embodiments, the second type of solvent is an
alcohol. For example, the alcohol may be a cyclic or acyclic,
branched or unbranched alkane having 6 to 12 carbon atoms and
substituted with a hydroxyl group (e.g., an alcohol). Non-limiting
examples of cyclic or acyclic, branched or unbranched alkanes
having 6 to 12 carbon atoms and substituted with a hydroxyl group
include isomers of heptanol, isomers of octanol, isomers of
nonanol, isomers of decanol, isomers of undecanol, isomers of
dodecanol, and combinations thereof.
[0025] Non-limiting examples of alcohols include isomers of octanol
(e.g., 1-octanol, 2-octanol, 3-octanol, 4-octanol), isomers of
methyl heptanol, isomers of ethylhexanol (e.g., 2-ethyl-1-hexanol,
3-ethyl-1-hexanol, 4-ethyl-1-hexanol), isomers of dimethylhexanol,
isomers of propylpentanol, isomers of methylethylpentanol, isomers
of trimethylpentanol, and combinations thereof. In a particular
embodiment, the cyclic or acyclic, branched or unbranched alkane
has 8 carbon atoms and is substituted with a hydroxyl group. In a
particular embodiment, the oxygenated solvent is isooctanol.
[0026] Non-limiting examples of oxygenated terpenes include
terpenes containing alcohol, aldehyde, ether, or ketone groups. In
some embodiments, the terpene comprises an ether-oxygen, for
example, eucalyptol, or a carbonyl oxygen, for example, menthone.
In some embodiments, the terpene is a terpene alcohol. Non-limiting
examples of terpene alcohols include linalool, geraniol, nopol,
.alpha.-terpineol, and menthol. Non-limiting examples of oxygenated
terpenes include eucalyptol, 1,8-cineol, menthone, and carvone.
[0027] As used herein, "alkyl aliphatic carboxylic acid ester"
refers to a compound or a blend of compounds having the general
formula:
##STR00001##
wherein R.sup.1 is an optionally substituted aliphatic group,
including those bearing heteroatom-containing substituent groups,
and R.sup.2 is a C.sub.1 to C.sub.6 alkyl group. In some
embodiments, R.sup.1 is C.sub.6 to C.sub.22 alkyl. In some
embodiments, R.sup.1 is substituted with at least one
heteroatom-containing substituent group. For example, wherein a
blend of compounds is provided and each R.sup.2 is --CH.sub.3 and
each R.sup.1 is independently a C.sub.6 to C.sub.22 aliphatic
group, the blend of compounds is referred to as methyl aliphatic
carboxylic acid esters, or methyl esters. In some embodiments, such
alkyl aliphatic carboxylic acid esters may be derived from a fully
synthetic process or from natural products, and thus comprise a
blend of more than one ester. In some embodiments, the alkyl
aliphatic carboxylic acid ester comprises butyl 3-hydroxybutyrate,
isopropyl 3-hydroxybutyrate, hexyl 3-hydroxylbutyrate, and
combinations thereof. Non-limiting examples of alkyl aliphatic
carboxylic acid esters include methyl octanoate, methyl decanoate,
a blend of methyl octanoate and methyl decanoate, methyl octenoate,
methyl decenoate, methyl dodecenoate, methyl tetradodecenoate, and
butyl 3-hydroxybutyrate.
[0028] In some embodiments, the emulsion or microemulsion may
comprise a branched or unbranched dialkylether having the formula
C.sub.nH.sub.2n+1OC.sub.mH.sub.2m+1 wherein n+m is from 6 to 16. In
some embodiments, n+m is from 6 to 12, or from 6 to 10, or from 6
to 8. Non-limiting examples of branched or unbranched dialkylether
compounds having the formula C.sub.nH.sub.2n+1OC.sub.mH.sub.2m+1
include isomers of C.sub.3H.sub.7OC.sub.3H.sub.7, isomers of
C.sub.4H.sub.9OC.sub.3H.sub.7, isomers of
C.sub.5H.sub.11OC.sub.3H.sub.7, isomers of
C.sub.6H.sub.13OC.sub.3H.sub.7, isomers of
C.sub.4H.sub.9OC.sub.4H.sub.9, isomers of
C.sub.4H.sub.9OC.sub.5H.sub.11, isomers of
C.sub.4H.sub.9OC.sub.6H.sub.13, isomers of
C.sub.5H.sub.11OC.sub.6H.sub.13, and isomers of
C.sub.6H.sub.13OC.sub.6H.sub.13. In a particular embodiment, the
branched or unbranched dialklyether is an isomer of
C.sub.6H.sub.13OC.sub.6H.sub.13 (e.g., dihexylether).
[0029] Other non-limiting examples of oxygenated solvents include
2-(acetoacetoxy)ethyl methacrylate, 2-(hydroxyethyl) methacrylate,
2,2-dimethyl-1,3-propanediol, 1,4-cyclohexanedimethanol, and
oxoacids having 3-8 carbon atoms.
[0030] In some embodiments, the second type of solvent is present
in an amount from about 0.5 wt % to about 25 wt %, or from about 1
wt % to about 20 wt %, or from about 1 wt % to about 15 wt %, or
from about 1 wt % to about 10 wt %, or from about 1 wt % and about
5 wt %, or from about 1 wt % and about 3 wt %, versus the total
microemulsion.
Other Types of Solvents
[0031] In some embodiments, the emulsion or microemulsion may
comprise additional types of solvents. Non-limiting examples of
such solvents include terpenes, terpineols, terpene alcohols,
aldehydes, ketones, esters, amines, and amides.
[0032] Terpenes are generally derived biosynthetically from units
of isoprene. Terpenes may be generally classified as monoterpenes
(e.g., having two isoprene units), sesquiterpenes (e.g., having 3
isoprene units), diterpenes, or the like. The term "terpenoid"
includes natural degradation products, such as ionones, and natural
and synthetic derivatives, e.g., terpene alcohols, ethers,
aldehydes, ketones, acids, esters, epoxides, and hydrogenation
products (e.g., see Ullmann's Encyclopedia of Industrial Chemistry,
2012, pages 29-45, herein incorporated by reference). In some
embodiments, the terpene is a naturally occurring terpene. In some
embodiments, the terpene is a non-naturally occurring terpene
and/or a chemically modified terpene (e.g., saturated terpene,
terpene amine, fluorinated terpene, or silylated terpene). Terpenes
that are modified chemically, such as by oxidation or rearrangement
of the carbon skeleton, may be referred to as terpenoids. Many
references use "terpene" and "terpenoid" interchangeably, and this
disclosure will adhere to that usage.
[0033] In some embodiments, the terpene is a non-oxygenated
terpene. In some embodiments, the terpene is citrus terpene. In
some embodiments, the terpene is d-limonene. In some embodiments,
the terpene is dipentene. In some embodiments, the terpene is
selected from the group consisting of d-limonene, nopol, alpha
terpineol, eucalyptol, dipentene, linalool, alpha-pinene,
beta-pinene, alpha-terpinene, geraniol, alpha-terpinyl acetate,
menthol, menthone, cineole, citranellol, and combinations thereof.
As used herein, "terpene" refers to a single terpene compound or a
blend of terpene compounds.
[0034] In some embodiments, the emulsion or microemulsion may
comprise an unsubstituted cyclic or acyclic, branched or unbranched
alkane. In some embodiments, the cyclic or acyclic, branched or
unbranched alkane has from 6 to 12 carbon atoms. Non-limiting
examples of unsubstituted, acyclic, unbranched alkanes include
hexane, heptane, octane, nonane, decane, undecane, dodecane, and
combinations thereof. Non-limiting examples of unsubstituted,
acyclic, branched alkanes include isomers of methylpentane (e.g.,
2-methylpentane, 3-methylpentane), isomers of dimethylbutane (e.g.,
2,2-dimethylbutane, 2,3-dimethylbutane), isomers of methylhexane
(e.g., 2-methylhexane, 3-methylhexane), isomers of ethylpentane
(e.g., 3-ethylpentane), isomers of dimethylpentane (e.g.,
2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane,
3,3-dimethylpentane), isomers of trimethylbutane (e.g.,
2,2,3-trimethylbutane), isomers of methylheptane (e.g.,
2-methylheptane, 3-methylheptane, 4-methylheptane), isomers of
dimethylhexane (e.g., 2,2-dimethylhexane, 2,3-dimethylhexane,
2,4-dimethylhexane, 2,5-dimethylhexane, 3,3-dimethylhexane,
3,4-dimethylhexane), isomers of ethylhexane (e.g., 3-ethylhexane),
isomers of trimethylpentane (e.g., 2,2,3-trimethylpentane,
2,2,4-trimethylpentane, 2,3,3-trimethylpentane,
2,3,4-trimethylpentane), isomers of ethylmethylpentane (e.g.,
3-ethyl-2-methylpentane, 3-ethyl-3-methylpentane), and combinations
thereof. Non-limiting examples of unsubstituted cyclic branched or
unbranched alkanes include cyclohexane, methylcyclopentane,
ethylcyclobutane, propylcyclopropane, isopropylcyclopropane,
dimethylcyclobutane, cycloheptane, methylcyclohexane,
dimethylcyclopentane, ethylcyclopentane, trimethylcyclobutane,
cyclooctane, methylcycloheptane, dimethylcyclohexane,
ethylcyclohexane, cyclononane, methylcyclooctane,
dimethylcycloheptane, ethylcycloheptane, trimethylcyclohexane,
ethylmethylcyclohexane, propylcyclohexane, cyclodecane, and
combinations thereof. In some embodiments, the unsubstituted cyclic
or acyclic, branched or unbranched alkane having from 6 to 12
carbon atoms is selected from the group consisting of heptane,
octane, nonane, decane, 2,2,4-trimethylpentane (isooctane), and
propylcyclohexane, and combinations thereof.
[0035] In some embodiments, the emulsion or microemulsion may
comprise unsubstituted acyclic branched alkene or unsubstituted
acyclic unbranched alkene having one or two double bonds and from 6
to 12 carbon atoms, or an unsubstituted acyclic branched alkene or
unsubstituted acyclic unbranched alkene having one or two double
bonds and from 6 to 10 carbon atoms. Non-limiting examples of
unsubstituted acyclic unbranched alkenes having one or two double
bonds and from 6 to 12 carbon atoms include isomers of hexene
(e.g., 1-hexene, 2-hexene), isomers of hexadiene (e.g.,
1,3-hexadiene, 1,4-hexadiene), isomers of heptene (e.g., 1-heptene,
2-heptene, 3-heptene), isomers of heptadiene (e.g., 1,5-heptadiene,
1-6, heptadiene), isomers of octene (e.g., 1-octene, 2-octene,
3-octene), isomers of octadiene (e.g., 1,7-octadiene), isomers of
nonene, isomers of nonadiene, isomers of decene, isomers of
decadiene, isomers of undecene, isomers of undecadiene, isomers of
dodecene, isomers of dodecadiene, and combinations thereof. In some
embodiments, the acyclic, unbranched alkene having one or two
double bonds and from 6 to 12 carbon atoms is an alpha-olefin
(e.g., 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene,
1-undecene, 1-dodecene). Non-limiting examples of unsubstituted,
acyclic, branched alkenes include isomers of methylpentene, isomers
of dimethylpentene, isomers of ethylpentene, isomers of
methylethylpentene, isomers of propylpentene, isomers of
methylhexene, isomers of ethylhexene, isomers of dimethylhexene,
isomers of methylethylhexene, isomers of methylheptene, isomers of
ethylheptene, isomers of dimethylhexptene, isomers of
methylethylheptene, and combinations thereof.
[0036] In some embodiments, the emulsion or microemulsion may
comprise an aromatic solvent having a boiling point from about 300
to about 400 degrees Fahrenheit. Non-limiting examples of aromatic
solvents having a boiling point from about 300 to about 400 degrees
Fahrenheit include butylbenzene, hexylbenzene, mesitylene, light
aromatic naphtha, heavy aromatic naphtha, and combinations
thereof.
[0037] In some embodiments, the emulsion or microemulsion may
comprise an aromatic solvent having a boiling point from about 175
to about 300 degrees Fahrenheit. Non-limiting examples of aromatic
liquid solvents having a boiling point from about 175 to about 300
degrees Fahrenheit include benzene, xylenes, and toluene.
[0038] In some embodiments, the emulsion or microemulsion may
comprise an amine of the formula NR.sup.1R.sup.2R.sup.3, wherein
R.sup.1, R.sup.2, and R.sup.3 are the same or different and are
C.sub.1-16 alkyl groups that are (i) branched or unbranched; (ii)
cyclic or acyclic; and (iii) substituted or unsubstituted. In some
embodiments any two of R.sup.1, R.sup.2, and R.sup.3 are joined
together to form a ring. In some embodiments, each of R.sup.1,
R.sup.2, and R.sup.3 are the same or different and are hydrogen or
alkyl groups that are (i) branched or unbranched; (ii) cyclic or
acyclic; and (iii) substituted or unsubstituted. In some
embodiments, any two of R.sup.1, R.sup.2, and R.sup.3 are joined
together to form a ring, provided at least one of R.sup.1, R.sup.2,
and R.sup.3 is a methyl or an ethyl group. In some embodiments,
R.sup.1 is C.sub.1-C.sub.6 alkyl group that is (i) branched or
unbranched; (ii) cyclic or acyclic; and (iii) substituted or
unsubstituted and R.sup.2 and R.sup.3 are hydrogen or a C.sub.8-16
alkyl group that is (i) branched or unbranched; (ii) cyclic or
acyclic; and (iii) substituted or unsubstituted. In some
embodiments, R.sup.2 and R.sup.3 may be joined together to form a
ring. In some embodiments, R.sup.1 is a methyl or an ethyl group
and R.sup.2 and R.sup.3 are the same or different and are
C.sub.8-16 alkyl groups that are (i) branched or unbranched; (ii)
cyclic or acyclic; and (iii) substituted or unsubstituted. In some
embodiments R.sup.2 and R.sup.3 may be joined together to form a
ring. In some embodiments, R.sup.1 is a methyl group and R.sup.2
and R.sup.3 are the same or different and are hydrogen or
C.sub.8-16 alkyl groups that are (i) branched or unbranched; (ii)
cyclic or acyclic; and (iii) substituted or unsubstituted. In some
embodiments R.sup.2 and R.sup.3 may be joined together to form a
ring. In some embodiments, R.sup.1 and R.sup.2 are the same or
different and are hydrogen or C.sub.1-C.sub.6 alkyl groups that are
(i) branched or unbranched; (ii) cyclic or acyclic; and (iii)
substituted or unsubstituted and R.sup.3 is a C.sub.8-16 alkyl
group that is (i) branched or unbranched; (ii) cyclic or acyclic;
and (iii) substituted or unsubstituted. In some embodiments,
R.sup.1 and R.sup.2 are the same or different and are a methyl or
an ethyl group and R.sup.3 is hydrogen or a C.sub.8-16 alkyl group
that is (i) branched or unbranched; (ii) cyclic or acyclic; and
(iii) substituted or unsubstituted. In some embodiments, R.sup.1
and R.sup.2 are methyl groups and R.sup.3 is hydrogen or a
C.sub.8-16 alkyl group that is (i) branched or unbranched; (ii)
cyclic or acyclic; and (iii) substituted or unsubstituted.
[0039] In some embodiments, the amine is of the formula
NR.sup.1R.sup.2R.sup.3, wherein R.sup.1 is methyl and R.sup.2 and
R.sup.3 are C.sub.8-16 alkyl groups that are (i) branched or
unbranched; (ii) cyclic or acyclic; and (iii) substituted or
unsubstituted. In some embodiments R.sup.2 and R.sup.3 are joined
together to form a ring. Non-limiting examples of amines include
isomers of N-methyl-octylamine, isomers of N-methyl-nonylamine,
isomers of N-methyl-decylamine, isomers of N-methylundecylamine,
isomers of N-methyldodecylamine, isomers of N-methyl
teradecylamine, isomers of N-methyl-hexadecylamine, and
combinations thereof. In some embodiments, the amine is
N-methyl-decylamine, N-methyl-hexadecylamine, or a combination
thereof.
[0040] In some embodiments, the amine is of the formula
NR.sup.1R.sup.2R.sup.3, wherein R.sup.1 is a methyl group and
R.sup.2 and R.sup.3 are the same or different and are C.sub.8-16
alkyl groups that are (i) branched or unbranched; (ii) cyclic or
acyclic; and (iii) substituted or unsubstituted. In some
embodiments R.sup.2 and R.sup.3 are joined together to form a ring.
Non-limiting examples of amines include isomers of
N-methyl-N-octyloctylamine, isomers of N-methyl-N-nonylnonylamine,
isomers of N-methyl-N-decyldecylamine, isomers of
N-methyl-N-undecylundecylamine, isomers of
N-methyl-N-dodecyldodecylamine, isomers of
N-methyl-N-tetradecylteradecylamine, isomers of
N-methyl-N-hexadecylhexadecylamine, isomers of
N-methyl-N-octylnonylamine, isomers of N-methyl-N-octyldecylamine,
isomers of N-methyl-N-octyldodecylamine, isomers of
N-methyl-N-octylundecylamine, isomers of
N-methyl-N-octyltetradecylamine, isomers of
N-methyl-N-octylhexadecylamine, N-methyl-N-nonyldecylamine, isomers
of N-methyl-N-nonyldodecylamine, isomers of
N-methyl-N-nonyltetradecylamine, isomers of
N-methyl-N-nonylhexadecylamine, isomers of
N-methyl-N-decylundecylamine, isomers of
N-methyl-N-decyldodecylamine, isomers of
N-methyl-N-decyltetradecylamine, isomers of
N-methyl-N-decylhexadecylamine, isomers of
N-methyl-N-dodecylundecylamine, isomers of
N-methyl-N-dodecyltetradecylamine, isomers of
N-methyl-N-dodecylhexadecylamine, isomers of
N-methyl-N-tetradecylhexadecylamine, and combinations thereof. In
some embodiments, the amine is selected from the group consisting
of N-methyl-N-octyloctylamine, isomers of
N-methyl-N-nonylnonylamine, isomers of N-methyl N-decyldecylamine,
isomers of N-methyl-N-undecylundecylamine, isomers of
N-methyl-N-dodecyldodecylamine, isomers of
N-methyl-N-tetradecylteradecylamine, and isomers of
N-methyl-N-hexadecylhexadecylamine, and combinations thereof. In
some embodiments, the amine is N-methyl-N-dodecyldodecylamine, one
or more isomers of N-methyl-N-hexadecylhexadecylamine, or
combinations thereof. In some embodiments, the amine is selected
from the group consisting of isomers of N-methyl-N-octylnonylamine,
isomers of N-methyl-N-octyldecylamine, isomers of
N-methyl-N-octyldodecylamine, isomers of
N-methyl-N-octylundecylamine, isomers of
N-methyl-N-octyltetradecylamine, isomers of
N-methyl-N-octylhexadecylamine, N-methyl-N-nonyldecylamine, isomers
of N-methyl-N-nonyldodecylamine, isomers of
N-methyl-N-nonyltetradecylamine, isomers of
N-methyl-N-nonylhexadecylamine, isomers of
N-methyl-N-decyldodecylamine, isomers of
N-methyl-N-decylundecylamine, isomers of
N-methyl-N-decyldodecylamine, isomers of
N-methyl-N-decyltetradecylamine, isomers of
N-methyl-N-decylhexadecylamine, isomers of
N-methyl-N-dodecylundecylamine, isomers of
N-methyl-N-dodecyltetradecylamine, isomers of
N-methyl-N-dodecylhexadecylamine, isomers of
N-methyl-N-tetradecylhexadecylamine, and combinations thereof. In
some embodiments, the cyclic or acyclic, branched or unbranched
tri-substituted amine is selected from the group consisting of
N-methyl-N-octyldodecylamine, N-methyl-N-octylhexadecylamine, and
N-methyl-N-dodecylhexadecylamine, and combinations thereof.
[0041] In some embodiments, the amine is of the formula
NR.sup.1R.sup.2R.sup.3, wherein R.sup.1 and R.sup.2 are methyl and
R.sup.3 is a C.sub.8-16 alkyl that is (i) branched or unbranched;
(ii) cyclic or acyclic; and (iii) substituted or unsubstituted.
Non-limiting examples of amines include isomers of
N,N-dimethylnonylamine, isomers of N,N-dimethyldecylamine, isomers
of N,N-dimethylundecylamine, isomers of N,N-dimethyldodecylamine,
isomers of N,N-dimethyltetradecylamine, and isomers of
N,N-dimethylhexadecylamine. In some embodiments, the amine is
selected from the group consisting of N,N-dimethyldecylamine,
isomers of N,N-dodecylamine, and isomers of
N,N-dimethylhexadecylamine.
[0042] In some embodiments, the emulsion or microemulsion may
comprise an amide solvent. In some embodiments, the amide is of the
formula N(C.dbd.OR.sup.4)R.sup.5R.sup.6, wherein R.sup.4, R.sup.5,
and R.sup.6 are the same or different and are hydrogen or
C.sub.4-16 alkyl groups wherein the alkyl groups are (i) branched
or unbranched; (ii) cyclic or acyclic; and (iii) substituted or
unsubstituted. In some embodiments R.sup.5 and R.sup.6 are joined
together to form a ring. In some embodiments, each of R.sup.4,
R.sup.5, and R.sup.6 are the same or different and are hydrogen or
C.sub.4-16 alkyl groups wherein the alkyl groups are (i) branched
or unbranched; (ii) cyclic or acyclic; and (iii) substituted or
unsubstituted, provided at least one of R.sup.4, R.sup.5, and
R.sup.6 is a methyl or an ethyl group. In some embodiments R.sup.5
and R.sup.6 are joined together to form a ring. In some
embodiments, R.sup.4 is hydrogen, C.sub.1-C.sub.6 alkyl, wherein
the alkyl group is (i) branched or unbranched; (ii) cyclic or
acyclic; and (iii) substituted or unsubstituted, and R.sup.5 and
R.sup.6 are the same or different and are hydrogen or C.sub.8-16
alkyl groups wherein the alkyl groups are (i) branched or
unbranched; (ii) cyclic or acyclic; and (iii) substituted or
unsubstituted. In some embodiments, R.sup.5 and R.sup.6 are joined
together to form a ring. In some embodiments, R.sup.4 is hydrogen,
methyl, or ethyl and R.sup.5 and R.sup.6 are C.sub.8-16 alkyl
groups wherein the alkyl groups are (i) branched or unbranched;
(ii) cyclic or acyclic; and (iii) substituted or unsubstituted. In
some embodiments, R.sup.5 and R.sup.6 are joined together to form a
ring. In some embodiments, R.sup.4 is hydrogen and R.sup.5 and
R.sup.6 are the same or different and are C.sub.8-16 alkyl groups
wherein the alkyl groups are (i) branched or unbranched; (ii)
cyclic or acyclic; and (iii) substituted or unsubstituted. In some
embodiments R.sup.5 and R.sup.6 are joined together to form a ring.
In some embodiments, R.sup.4 and R.sup.5 are the same or different
and are hydrogen or C.sub.1-C.sub.6 alkyl groups wherein the alkyl
groups are (i) branched or unbranched; (ii) cyclic or acyclic; and
(iii) substituted or unsubstituted and R.sup.6 is a C.sub.8-16
alkyl group that is (i) branched or unbranched; (ii) cyclic or
acyclic; and (iii) substituted or unsubstituted. In some
embodiments, R.sup.4 and R.sup.5 are the same or different and are
independently hydrogen, methyl, or ethyl and R.sup.6 is a
C.sub.8-16 alkyl group that is (i) branched or unbranched; (ii)
cyclic or acyclic; and (iii) substituted or unsubstituted. In some
embodiments, R.sup.4 and R.sup.5 are hydrogen and R.sup.6 is a
C.sub.8-16 alkyl group that is (i) branched or unbranched; (ii)
cyclic or acyclic; and (iii) substituted or unsubstituted. In some
embodiments, R.sup.6 is hydrogen or R.sup.6 is a C.sub.1-6 alkyl
group that is (i) branched or unbranched; (ii) cyclic or acyclic;
and (iii) substituted or unsubstituted and R.sup.4 and R.sup.5 are
the same or different and are C.sub.8-16 alkyl groups wherein the
alkyl groups are (i) branched or unbranched; (ii) cyclic or
acyclic; and (iii) substituted or unsubstituted. In some
embodiments, R.sup.6 is hydrogen, methyl, or ethyl and R.sup.4 and
R.sup.5 are the same or different and are C.sub.8-16 alkyl groups
wherein the alkyl groups are (i) branched or unbranched; (ii)
cyclic or acyclic; and (iii) substituted or unsubstituted. In some
embodiments, R.sup.6 is hydrogen and R.sup.4 and R.sup.5 are the
same or different and are C.sub.8-16 alkyl groups wherein the alkyl
groups are (i) branched or unbranched; (ii) cyclic or acyclic; and
(iii) substituted or unsubstituted. In some embodiments, R.sup.5
and R.sup.6 are the same or different and are hydrogen or C.sub.1-6
alkyl groups wherein the alkyl groups are (i) branched or
unbranched; (ii) cyclic or acyclic; and (iii) substituted or
unsubstituted, and R.sup.4 is a C.sub.8-16 alkyl group that is (i)
branched or unbranched; (ii) cyclic or acyclic; and (iii)
substituted or unsubstituted. In some embodiments, R.sup.5 and
R.sup.6 are the same or different and are independently hydrogen,
methyl, or ethyl and R.sup.4 is a C.sub.8-16 alkyl group that is
(i) branched or unbranched; (ii) cyclic or acyclic; and (iii)
substituted or unsubstituted. In some embodiments, R.sup.5 and
R.sup.6 are hydrogen and R.sup.4 is a C.sub.8-16 alkyl group that
is (i) branched or unbranched; (ii) cyclic or acyclic; and (iii)
substituted or unsubstituted.
[0043] In some embodiments, the amide is of the formula
N(C.dbd.OR.sup.4)R.sup.5R.sup.6, wherein each of R.sup.4, R.sup.5,
and R.sup.6 are the same or different and are C.sub.4-16 alkyl
groups wherein the alkyl groups are (i) branched or unbranched;
(ii) cyclic or acyclic; and (iii) substituted or unsubstituted. In
some embodiments R.sup.5 and R.sup.6 are joined together to form a
ring. In some embodiments, the amide is of the formula N(C.dbd.O
R.sup.4)R.sup.5R.sup.6, wherein each of R.sup.4, R.sup.5, and
R.sup.6 are the same or different and are C.sub.8-16 alkyl groups
wherein the alkyl groups are (i) branched or unbranched; (ii)
cyclic or acyclic; and (iii) substituted or unsubstituted. In some
embodiments R.sup.5 and R.sup.6 are joined together to form a ring.
Non-limiting examples of amides include N,N-dioctyloctamide,
N,N-dinonylnonamide, N,N-didecyldecamide, N,N-didodecyldodecamide,
N,N-diundecylundecamide, N,N-ditetradecyltetradecamide,
N,N-dihexadecylhexadecamide, N,N-didecyloctamide,
N,N-didodecyloctamide, N,N-dioctyldodecamide,
N,N-didecyldodecamide, N,N-dioctylhexadecamide,
N,N-didecylhexadecamide, N,N-didodecylhexadecamide, and
combinations thereof. In some embodiments, the amide is
N,N-dioctyldodecamide, N,N-didodecyloctamide, or a combination
thereof.
[0044] In some embodiments, the amide is of the formula
N(C.dbd.OR.sup.4)R.sup.5R.sup.6, wherein R.sup.6 is selected from
the group consisting of hydrogen, methyl, ethyl, propyl and
isopropyl, and R.sup.4 and R.sup.5 are the same or different and
are C.sub.4-16 alkyl groups wherein the alkyl groups are (i)
branched or unbranched; (ii) cyclic or acyclic; and (iii)
substituted or unsubstituted. In some embodiments, R.sup.6 is
selected from the group consisting of hydrogen, methyl, ethyl,
propyl and isopropyl, and R.sup.4 and R.sup.5 are the same or
different and are C.sub.4-8 alkyl groups wherein the alkyl groups
are (i) branched or unbranched; (ii) cyclic or acyclic; and (iii)
substituted or unsubstituted. In some embodiments, at least one of
R.sup.4 and R.sup.5 is substituted with a hydroxyl group. In some
embodiments, at least one of R.sup.4 and R.sup.5 is C.sub.1-6 alkyl
substituted with a hydroxyl group.
[0045] In some embodiments, the amide is of the formula
N(C.dbd.OR.sup.4)R.sup.5R.sup.6, wherein R.sup.6 is C.sub.1-C.sub.3
alkyl and R.sup.4 and R.sup.5 are the same or different and are
C.sub.4-16 alkyl groups that are (i) branched or unbranched; (ii)
cyclic or acyclic; and (iii) substituted or unsubstituted. In some
embodiments, R.sup.6 is selected from the group consisting of
methyl, ethyl, propyl, and isopropyl, and R.sup.4 and R.sup.5 are
the same or different and are C.sub.4-16 alkyl groups that are (i)
branched or unbranched; (ii) cyclic or acyclic; and (iii)
substituted or unsubstituted. In some embodiments, R.sup.6 is
selected from the group consisting of methyl, ethyl, propyl, and
isopropyl, and R.sup.4 and R.sup.5 are the same or different and
are C.sub.8-16 alkyl groups that are (i) branched or unbranched;
(ii) cyclic or acyclic; and (iii) substituted or unsubstituted. In
some embodiments, at least one of R.sup.4 and R.sup.5 is
substituted with a hydroxyl group. In some embodiments, R.sup.6 is
selected from the group consisting of methyl, ethyl, propyl, and
isopropyl, and R.sup.4 and R.sup.5 are the same or different and
are C.sub.4-16 alkyl groups that are (i) branched or unbranched;
(ii) cyclic or acyclic; and (iii) substituted or unsubstituted. In
some embodiments at least one of R.sup.4 and R.sup.5 is C.sub.1-16
alkyl substituted with a hydroxyl group.
[0046] Non-limiting examples of amides include
N,N-di-tert-butylformamide, N,N-dipentylformamide,
N,N-dihexylformamide, N,N-diheptylformamide, N,N-dioctylformamide,
N,N-dinonylformamide, N,N-didecylformamide, N,N-diundecylformamide,
N,N-didodecylformamide, N,N-dihydroxymethylformamide,
N,N-di-tert-butylacetamide, N,N-dipentylacetamide,
N,N-dihexylacetamide, N,N-diheptylacetamide, N,N-dioctylacetamide,
N,N-dinonylacetamide, N,N-didecylacetamide, N,N-diundecylacetamide,
N,N-didodecylacetamide, N,N-dihydroxymethylacetamide,
N,N-dimethylpropionamide, N,N-diethylpropionamide,
N,N-dipropylpropionamide, N,N-di-n-propylpropionamide
N,N-diisopropylpropionamide, N,N-dibutylpropionamide,
N,N-di-n-butylpropionamide, N,N-di-sec-butylpropionamide,
N,N-diisobutylpropionamide or N,N-di-tert-butylpropionamide,
N,N-dipentylpropionamide, N,N-dihexylpropionamide,
N,N-diheptylpropionamide, N,N-dioctylpropionamide,
N,N-dinonylpropionamide, N,N-didecylpropionamide,
N,N-diundecylpropionamide, N,N-didodecylpropionamide,
N,N-dimethyl-n-butyramide, N,N-diethyl-n-butyramide,
N,N-dipropyl-n-butyramide, N,N-di-n-propyl-n-butyramide or
N,N-diisopropyl-n-butyramide, N,N-dibutyl-n-butyramide,
N,N-di-n-butyl-n-butyramide, N,N-di-sec-butyl-n-butyramide,
N,N-diisobutyl-n-butyramide, N,N-di-tert-butyl-n-butyramide,
N,N-dipentyl-n-butyramide, N,N-dihexyl-n-butyramide,
N,N-diheptyl-n-butyramide, N,N-dioctyl-n-butyramide,
N,N-dinonyl-n-butyramide, N,N-didecyl-n-butyramide,
N,N-diundecyl-n-butyramide, N,N-didodecyl-n-butyramide,
N,N-dipentylisobutyramide, N,N-dihexylisobutyramide,
N,N-diheptylisobutyramide, N,N-dioctylisobutyramide,
N,N-dinonylisobutyramide, N,N-didecylisobutyramide,
N,N-diundecylisobutyramide, N,N-didodecylisobutyramide,
N,N-pentylhexylformamide, N,N-pentylhexylacetamide,
N,N-pentylhexylpropionamide, N,N-pentylhexyl-n-butyramide,
N,N-pentylhexylisobutyramide, N,N-methylethylpropionamide,
N,N-methyl-n-propylpropionamide, N,N-methylisopropylpropionamide,
N,N-methyl-n-butylpropionamide, N,N-methylethyl-n-butyramide,
N,N-methyl-n-butyramide, N,N-methylisopropyl-n-butyramide,
N,N-methyl-n-butyl-n-butyramide, N,N-methylethylisobutyramide,
N,N-methyl-n-propylisobutyramide, N,N-methylisopropylisobutyramide,
and N,N-methyl-n-butylisobutyramide. In some embodiments, the amide
is selected from the group consisting of N,N-dioctyldodecacetamide,
N,N-methyl-N-octylhexadecdidodecylacetamide,
N-methyl-N-hexadecyldodecylhexadecacetamide, and combinations
thereof.
[0047] In some embodiments, the amide is of the formula
N(C.dbd.OR.sup.4)R.sup.5R.sup.6, wherein R.sup.6 is hydrogen or a
methyl group and R.sup.4 and R.sup.5 are C.sub.8-16 alkyl groups
that are (i) branched or unbranched; (ii) cyclic or acyclic; and
(iii) substituted or unsubstituted. Non-limiting amides include
isomers of N-methyloctamide, isomers of N-methylnonamide, isomers
of N-methyldecamide, isomers of N-methylundecamide, isomers of N
methyldodecamide, isomers of N methylteradecamide, and isomers of
N-methyl-hexadecamide. In some embodiments, the amides are selected
from the group consisting of N-methyloctamide, N-methyldodecamide,
N-methylhexadecamide, and combinations thereof.
[0048] Non-limiting amides include isomers of
N-methyl-N-octyloctamide, isomers of N-methyl-N-nonylnonamide,
isomers of N-methyl-N-decyldecamide, isomers of N methyl-N
undecylundecamide, isomers of N methyl-N-dodecyldodecamide, isomers
of N methyl N-tetradecylteradecamide, isomers of
N-methyl-N-hexadecylhdexadecamide, isomers of
N-methyl-N-octylnonamide, isomers of N-methyl-N-octyldecamide,
isomers of N-methyl-N-octyldodecamide, isomers of
N-methyl-N-octylundecamide, isomers of
N-methyl-N-octyltetradecamide, isomers of
N-methyl-N-octylhexadecamide, N-methyl-N-nonyldecamide, isomers of
N-methyl-N-nonyldodecamide, isomers of
N-methyl-N-nonyltetradecamide, isomers of
N-methyl-N-nonylhexadecamide, isomers of
N-methyl-N-decyldodecamide, isomers of N methyl-N-decylundecamide,
isomers of N-methyl-N-decyldodecamide, isomers of
N-methyl-N-decyltetradecamide, isomers of
N-methyl-N-decylhexadecamide, isomers of N
methyl-N-dodecylundecamide, isomers of N
methyl-N-dodecyltetradecamide, isomers of
N-methyl-N-dodecylhexadecamide, isomers of N
methyl-N-tetradecylhexadecamide, and combinations thereof. In some
embodiments, the amide is selected from the group consisting of
isomers of N-methyl-N-octyloctamide, isomers of
N-methyl-N-nonylnonamide, isomers of N-methyl-N-decyldecamide,
isomers of N methyl-N undecylundecamide, isomers of N
methyl-N-dodecyldodecamide, isomers of N methyl
N-tetradecylteradecamide, isomers of
N-methyl-N-hexadecylhdexadecamide, and combinations thereof. In
some embodiments, amide is selected from the group consisting of
N-methyl-N-octyloctamide, N methyl-N-dodecyldodecamide, and
N-methyl-N-hexadecylhexadecamide. In some embodiments, the amide is
selected from the group consisting of isomers of
N-methyl-N-octylnonamide, isomers of N-methyl-N-octyldecamide,
isomers of N-methyl-N-octyldodecamide, isomers of
N-methyl-N-octylundecamide, isomers of
N-methyl-N-octyltetradecamide, isomers of
N-methyl-N-octylhexadecamide, N-methyl-N-nonyldecamide, isomers of
N-methyl-N-nonyldodecamide, isomers of
N-methyl-N-nonyltetradecamide, isomers of
N-methyl-N-nonylhexadecamide, isomers of
N-methyl-N-decyldodecamide, isomers of N methyl-N-decylundecamide,
isomers of N-methyl-N-decyldodecamide, isomers of
N-methyl-N-decyltetradecamide, isomers of
N-methyl-N-decylhexadecamide, isomers of N
methyl-N-dodecylundecamide, isomers of N
methyl-N-dodecyltetradecamide, isomers of
N-methyl-N-dodecylhexadecamide, and isomers of N
methyl-N-tetradecylhexadecamide. In some embodiments, the amide is
selected from the group consisting of N-methyl-N-octyldodecamide,
N-methyl-N-octylhexadecamide, and
N-methyl-N-dodecylhexadecamide.
[0049] In some embodiments, the amide is of the formula
N(C.dbd.OR.sup.4)R.sup.5R.sup.6, wherein R.sup.5 and R.sup.6 are
the same or different and are hydrogen or C.sub.1-C.sub.3 alkyl
groups and R.sup.4 is a C.sub.4-16 alkyl group that is (i) branched
or unbranched; (ii) cyclic or acyclic; and (iii) substituted or
unsubstituted. In some embodiments, R.sup.5 and R.sup.6 are the
same or different and are selected from the group consisting of
hydrogen, methyl, ethyl, propyl and isopropyl, and R.sup.4 is a
C.sub.4-16 alkyl group that is (i) branched or unbranched; (ii)
cyclic or acyclic; and (iii) substituted or unsubstituted. In some
embodiments, R.sup.5 and R.sup.6 are the same or different and are
selected from the group consisting of hydrogen, methyl, ethyl,
propyl and isopropyl and R.sup.4 is a C.sub.8-16 alkyl group that
is (i) branched or unbranched; (ii) cyclic or acyclic; and (iii)
substituted or unsubstituted. In some embodiments, R.sup.4 is
substituted with a hydroxyl group. In some embodiments, R.sup.5 and
R.sup.6 are the same or different and are selected from the group
consisting of hydrogen, methyl, ethyl, propyl, and isopropyl, and
R.sup.4 is selected from the group consisting of tert-butyl and
C.sub.5-16 alkyl groups that are (i) branched or unbranched; (ii)
cyclic or acyclic; and (iii) substituted or unsubstituted, and
C.sub.1-16 alkyl groups that are (i) branched or unbranched; (ii)
cyclic or acyclic; and (iii) substituted with a hydroxyl group.
[0050] In some embodiments, the amide is of the formula
N(C.dbd.OR.sup.4)R.sup.5R.sup.6, wherein R.sup.5 and R.sup.6 are
methyl groups and R.sup.4 is a C.sub.8-16 alkyl group that is (i)
branched or unbranched; (ii) cyclic or acyclic; and (iii)
substituted or unsubstituted. Non-limiting examples of amides
include isomers of N,N-dimethyloctamide, isomers of
N,N-dimethylnonamide, isomers of N,N-dimethyldecamide, isomers of
N,N-dimethylundecamide, isomers of N,N-dimethyldodecamide, isomers
of N,N-dimethyltetradecamide, isomers of N,N-dimethylhexadecamide,
and combinations thereof. In some embodiments, the cyclic or
acyclic, branched or unbranched tri-substituted amines is selected
from the group consisting of N,N-dimethyloctamide, N,N-dodecamide,
and N,N-dimethylhexadecamide.
[0051] In some embodiments, a solvent (e.g., a terpene) may be
extracted from a natural source (e.g., citrus, pine), and may
comprise one or more impurities present from the extraction
process. In some embodiments, the solvent comprises a crude cut
(e.g., uncut crude oil, e.g., made by settling, separation,
heating, etc.). In some embodiments, the solvent is a crude oil
(e.g., naturally occurring crude oil, uncut crude oil, crude oil
extracted from the wellbore, synthetic crude oil, crude citrus oil,
crude pine oil, eucalyptus, etc.). In some embodiments, the solvent
comprises a citrus extract (e.g., crude orange oil, orange oil,
etc.). In some embodiments, the solvent is a citrus extract (e.g.,
crude orange oil, orange oil, etc.).
Aqueous Phase
[0052] In some embodiments, an emulsion or microemulsion comprises
an aqueous phase. Generally, the aqueous phase comprises water. The
water may be provided from any suitable source (e.g., sea water,
fresh water, deionized water, reverse osmosis water, water from
field production). In some embodiments, the emulsion or
microemulsion comprises from about 1 wt % to about 60 wt %, or from
about 10 wt % to about 55 wt %, or from about 15 wt % to about 45
wt %, or from about 25 wt % to about 45 wt % of water, or from
about 5 wt % to about 75 wt % versus the total weight of the
emulsion or microemulsion composition. In some embodiments, the
surfactant and one or more solvents may be provided at select wt %
as described herein, and the remainder of the composition may be
the aqueous phase (e.g., water). The aqueous phase may comprise
dissolved salts. Non-limiting examples of dissolved salts include
salts comprising K, Na, Br, Cr, Cs, or Bi, for example, halides of
these metals, including NaCl, KCl, CaCl.sub.2, MgCl, and
combinations thereof.
Surfactants
[0053] Generally, the emulsion or microemulsion comprises a
surfactant. In some embodiments, the emulsion or microemulsion
comprises a first surfactant and a second surfactant. In some
embodiments the emulsion or microemulsion comprises a first
surfactant and a co-surfactant. In some embodiments, the emulsion
or microemulsion comprises a first surfactant, a second surfactant
and a co-surfactant. The term surfactant is given its ordinary
meaning in the art and generally refers to compounds having an
amphiphilic structure which gives them a specific affinity for
oil/water-type and water/oil-type interfaces. In some embodiments,
the affinity helps the surfactants to reduce the free energy of
these interfaces and to stabilize the dispersed phase of an
emulsion or microemulsion.
[0054] The term surfactant includes but is not limited to nonionic
surfactants, anionic surfactants, cationic surfactants, amphoteric
surfactants, zwitterionic surfactants, switchable surfactants,
cleavable surfactants, dimeric or gemini surfactants, glucamide
surfactants, alkylpolyglycoside surfactants, extended surfactants
containing a nonionic spacer arm central extension and an ionic or
nonionic polar group, and combinations thereof. Nonionic
surfactants generally do not contain any charges. Anionic
surfactants generally possess a net negative charge. Cationic
surfactants generally possess a net positive charge. Amphoteric
surfactants generally have both positive and negative charges,
however, the net charge of the surfactant can be positive,
negative, or neutral, depending on the pH of the solution.
Zwitterionic surfactants are generally not pH dependent. A
zwitterion is a neutral molecule with a positive and a negative
electrical charge, though multiple positive and negative charges
can be present.
[0055] "Extended surfactants" are defined herein to be surfactants
having propoxylated/ethoxylated spacer arms. The extended chain
surfactants are intramolecular mixtures having at least one
hydrophilic portion and at least one lipophilic portion with an
intermediate polarity portion in between the hydrophilic portion
and the lipophilic portion; the intermediate polarity portion may
be referred to as a spacer. They attain high solubilization in the
single phase emulsion or microemulsion, and are in some instances,
insensitive to temperature and are useful for a wide variety of oil
types, such as natural or synthetic polar oil types in a
non-limiting embodiment. More information related to extended chain
surfactants may be found in U.S. Pat. No. 8,235,120, which is
incorporated herein by reference in its entirety.
[0056] The term co-surfactant as used herein is given its ordinary
meaning in the art and refers to compounds (e.g., pentanol) that
act in conjunction with surfactants to form an emulsion or
microemulsion.
[0057] In some embodiments, the one or more surfactants is a
surfactant described in U.S. patent application Ser. No.
14/212,731, filed Mar. 14, 2014, entitled "METHODS AND COMPOSITIONS
FOR USE IN OIL AND/OR GAS WELLS," now published as US/2014/0284053
on Sep. 25, 2014, herein incorporated by reference. In some
embodiments, the surfactant is a surfactant described in U.S.
patent application Ser. No. 14/212,763, filed Mar. 14, 2014,
entitled "METHODS AND COMPOSITIONS FOR USE IN OIL AND/OR GAS
WELLS," now published as US/2014/0338911 on Nov. 20, 2014, and
granted on Feb. 26, 2004 as U.S. Pat. No. 9,884,988 herein
incorporated by reference.
[0058] In some embodiments, the emulsion or microemulsion comprises
from about 1 wt % to about 50 wt %, or from about 1 wt % to about
40 wt %, or from about 1 wt % to about 35 wt %, or from about 5 wt
% to about 40 wt %, or from about 5 wt % to about 35 wt %, or from
about 10 wt % to about 30 wt %, or from about 10 wt % to about 20
wt % of the surfactant versus the total weight of the emulsion or
microemulsion.
[0059] In some embodiments, the surfactants described herein in
conjunction with solvents, generally form emulsions or
microemulsions that may be diluted to a use concentration to form
an oil-in-water nanodroplet dispersion. In some embodiments, the
surfactants generally have hydrophile-lipophile balance (HLB)
values from 8 to 18, or from 8 to 14.
[0060] Suitable surfactants for use with the compositions and
methods are generally described herein. In some embodiments, the
surfactant comprises a hydrophilic hydrocarbon surfactant.
[0061] In some embodiments, the surfactant comprises a nonionic
surfactant. In some embodiments, the surfactant is a nonionic
alkoxylated aliphatic alcohol having from 3 to 40 ethylene oxide
(EO) units and from 0 to 20 propylene oxide (PO) units. The term
aliphatic alcohol generally refers to a branched or linear,
saturated or unsaturated aliphatic moiety having from 6 to 18
carbon atoms. In some embodiments, the surfactant is a nonionic
alkoxylated aliphatic alcohol having from 3 to 40 ethylene oxide
(EO) units.
[0062] In some embodiments, the hydrophilic hydrocarbon surfactant
comprises an alcohol ethoxylate, wherein the alcohol ethoxylate
contains a hydrocarbon group of 10 to 18 carbon atoms and contains
an ethoxylate group of 5 to 12 ethylene oxide units.
[0063] In some embodiments, the surfactant is selected from the
group consisting of ethoxylated fatty acids, ethoxylated fatty
amines, and ethoxylated fatty amides wherein the fatty portion is a
branched or linear, saturated or unsaturated aliphatic hydrocarbon
moiety having from 6 to 18 carbon atoms.
[0064] In some embodiments, the surfactant is an alkoxylated castor
oil. In some embodiments, the surfactant is a sorbitan ester
derivative. In some embodiments the surfactant is an ethylene
oxide-propylene oxide copolymer wherein the total number of EO and
PO units is from 8 to 40 units. In some embodiments, the surfactant
is an alkoxylated tristyryl phenol containing from 6 to 100 total
ethylene oxide (EO) and propylene oxide (PO) units.
[0065] In some embodiments, the surfactant is an amine-based
surfactant selected from the group consisting of ethoxylated
alkylene amines, ethoxylated alkyl amines, propoxylated alkylene
amines, propoxylated alkyl amines, ethoxylated-propoxylated
alkylene amines and ethoxylated propoxylated alkyl amines. The
ethoxylated/propoxylated alkylene or alkyl amine surfactant
component preferably includes more than one nitrogen atom per
molecule. Suitable amines include ethylenediaminealkoxylate and
diethylenetriaminealkoxylate.
[0066] In some embodiments, the surfactant includes an alkanolamide
surfactant. In some embodiments, the surfactant includes an
alkanolamide surfactant that is a (C.sub.6-C.sub.18) aliphatic
amide having groups R.sup.1 and R.sup.2 substituted on the amide
nitrogen, wherein R.sup.1 and R.sup.2 are each independently
selected from the group consisting of --H, --(C.sub.1-C.sub.18)
aliphatic hydrocarbon, --(C.sub.2H.sub.4O).sub.nH,
--(C.sub.3H.sub.6O).sub.nH,
--(C.sub.2H.sub.4O).sub.n(C.sub.3H.sub.6O).sub.mH, and
(C.sub.1-C.sub.18) aliphatic alcohol, and n is about 1 to about 50
and m is 0 to about 20, wherein at least one of R.sup.1 and R.sup.2
is --(C.sub.2H.sub.4O).sub.nH, --(C.sub.3H.sub.6O).sub.nH,
--(C.sub.2H.sub.4O).sub.n(C.sub.3H.sub.6O).sub.mH, or
(C.sub.1-C.sub.18) aliphatic alcohol, and n is about 1 to about 50
and m is 0 to about 20.
[0067] In some embodiments, the surfactant includes
N,N-bis(hydroxyethyl)coco amides, N,N-bis(hydroxyethyl)coco fatty
acid amides, cocamide DEA, cocamide diethanolamine, coco
diethanolamides, coco diethanolamine, coco fatty acid
diethanolamides, coconut DEA, coconut diethanolamides, coconut oil
diethanolamides, coconut oil diethanolamine, lauric diethanolamide,
or lauramide DEA. In some embodiments the surfactant includes an
alkoxylated cocamide DEA, alkoxyated lauramide DEA, ethoxylated
cocamide DEA, or ethoxylated lauramide DEA.
[0068] The alkanolamide surfactant can have the structure:
##STR00002##
wherein R.sup.3 is a C.sub.6-C.sub.18 aliphatic hydrocarbon group,
and wherein R.sup.1 and R.sup.2 are each independently selected
from the group consisting of --H, --(C.sub.1-C.sub.18) aliphatic
hydrocarbon, --(C.sub.2H.sub.4O).sub.nH,
--(C.sub.3H.sub.6O).sub.nH,
--(C.sub.2H.sub.4O).sub.n(C.sub.3H.sub.6O).sub.mH, and n is about 1
to about 50 and m is 0 to about 20, wherein at least one of R.sup.1
and R.sup.2 is --(C.sub.2H.sub.4O).sub.nH,
--(C.sub.3H.sub.6O).sub.nH,
--(C.sub.2H.sub.4O).sub.n(C.sub.3H.sub.6O).sub.mH, or
(C.sub.1-C.sub.18) aliphatic alcohol, and n is about 1 to about 50
and m is 0 to about 20.
[0069] In some embodiments the surfactant is an alkoxylated
polyimine with a relative solubility number (RSN) in the range of
5-20. As will be known to those of ordinary skill in the art, RSN
values are generally determined by titrating water into a solution
of surfactant in 1,4 dioxane. The RSN values is generally defined
as the amount of distilled water necessary to be added to produce
persistent turbidity. In some embodiments the surfactant is an
alkoxylated novolac resin (also known as a phenolic resin) with a
relative solubility number in the range of 5-20. In some
embodiments the surfactant is a block copolymer surfactant with a
total molecular weight greater than 5000 daltons. The block
copolymer may have a hydrophobic block that is comprised of a
polymer chain that is linear, branched, hyperbranched, dendritic or
cyclic.
[0070] In some embodiments, the surfactant is an aliphatic
polyglycoside having the following formula:
##STR00003##
[0071] wherein R.sup.3 is an aliphatic group having from 6 to 18
carbon atoms; each R.sup.4 is independently selected from H,
--CH.sub.3, or --CH.sub.2CH.sub.3; Y is an average number of from
about 0 to about 5; and X is an average degree of polymerization
(DP) of from about 1 to about 4; G is the residue of a reducing
saccharide, for example, a glucose residue. In some embodiments, Y
is zero.
[0072] In some embodiments, the surfactant is an aliphatic
glycamide having the following formula:
##STR00004##
wherein R.sup.6 is an aliphatic group having from 6 to 18 carbon
atoms; R.sup.5 is an alkyl group having from 1 to 6 carbon atoms;
and Z is --CH.sub.2(CH.sub.2OH).sub.bCH.sub.2OH, wherein b is from
3 to 5. In some embodiments, R.sup.5 is --CH.sub.3. In some
embodiments, R.sup.6 is an alkyl group having from 6 to 18 carbon
atoms. In some embodiments, b is 3. In some embodiments, b is 4. In
some embodiments, b is 5.
[0073] Suitable anionic surfactants include, but are not
necessarily limited to, alkali metal alkyl sulfates, alkyl or
alkylaryl sulfonates, linear or branched alkyl ether sulfates and
sulfonates, alcohol polypropoxylated and/or polyethoxylated
sulfates, alkyl or alkylaryl disulfonates, alkyl disulfates, alkyl
sulphosuccinates, dialkyl sulphosuccinates alkyl ether sulfates,
linear and branched ether sulfates, fatty carboxylates, alkyl
sarcosinates, alkyl phosphates and combinations thereof.
[0074] In some embodiments, the surfactant is an aliphatic sulfate
wherein the aliphatic moiety is a branched or linear, saturated or
unsaturated aliphatic hydrocarbon moiety having from 6 to 18 carbon
atoms. In some embodiments, the surfactant is an aliphatic
sulfonate wherein the aliphatic moiety is a branched or linear,
saturated or unsaturated aliphatic hydrocarbon moiety having from 6
to 18 carbon atoms.
[0075] In some embodiments, the surfactant is an aliphatic alkoxy
sulfate wherein the aliphatic moiety is a branched or linear,
saturated or unsaturated aliphatic hydrocarbon moiety having from 6
to 18 carbon atoms and from 4 to 40 total ethylene oxide (EO) and
propylene oxide (PO) units.
[0076] In some embodiments, the surfactant is an aliphatic-aromatic
sulfate wherein the aliphatic moiety is a branched or linear,
saturated or unsaturated aliphatic hydrocarbon moiety having from 6
to 18 carbon atoms. In some embodiments, the surfactant is an
aliphatic-aromatic sulfonate wherein the aliphatic moiety is a
branched or linear, saturated or unsaturated aliphatic hydrocarbon
moiety having from 6 to 18 carbon atoms.
[0077] In some embodiments, the surfactant is an ester or half
ester of sulfosuccinic acid with monohydric alcohols.
[0078] In some embodiments, the surfactant is a quaternary
alkylammonium salt or a quaternary alkylbenzylammonium salt, whose
alkyl groups have 1 to 24 carbon atoms (e.g., a halide, sulfate,
phosphate, acetate, or hydroxide salt). In some embodiments, the
surfactant is a quaternary alkylbenzylammonium salt, whose alkyl
groups have 1-24 carbon atoms (e.g., a halide, sulfate, phosphate,
acetate, or hydroxide salt). In some embodiments, the surfactant is
an alkylpyridinium, an alkylimidazolinium, or an alkyloxazolinium
salt whose alkyl chain has up to 18 carbons atoms (e.g., a halide,
sulfate, phosphate, acetate, or hydroxide salt).
[0079] In some embodiments, the surfactant is a cationic surfactant
such as, monoalkyl quaternary amines, such as cocotrimethylammonium
chloride, cetyltrimethylammonium chloride,
stearyltrimethylannnonium chloride, soyatrimethylannnonium
chloride, behentrimethylammonium chloride, and the like and
mixtures thereof. Other suitable cationic surfactants that may be
useful include, but are not necessarily limited to,
dialkylquaternary amines such as dicetyldimethylammonium chloride,
dicocodimethylannnonium chloride, distearyldimethylammonium
chloride, and the like and mixtures thereof.
[0080] In some embodiments, the surfactant is an amine oxide (e.g.,
dodecyldimethylamine oxide, lauramine oxide, laurylamidopropylamine
oxide, cocamidopropylamine oxide). In some embodiments, the
surfactant is amphoteric or zwitterionic, including sultaines
(e.g., cocamidopropyl hydroxysultaine, lauryl sultaine, lauryl
sulfobetaine, coco sultaine, coco sulfobetaine), betaines (e.g.,
cocamidopropyl betaine, lauramidopropyl betaine, or lauryl betaine,
coco betaine), or phosphates (e.g., lecithin).
[0081] Non-limiting examples of suitable surfactants include
nonionic surfactants with linear or branched structure, including,
but not limited to, alkoxylated alcohols, alkoxylated fatty
alcohols, alkoxylated castor oils, alkoxylated fatty acids, and
alkoxylated fatty amides with a hydrocarbon chain of at least 8
carbon atoms and 5 units or more of alkoxylation. The term
alkoxylation includes ethoxylation and propoxylation. Other
nonionic surfactants include alkyl glycosides and alkyl glucamides.
Additional surfactants are described herein. Other non-limiting
examples of surfactants include adsorption modifiers, foamers,
surface tension lowering enhancers, and emulsion breaking
additives. Specific examples of such surfactants include cationic
surfactants with a medium chain length, linear or branched anionic
surfactants, alkyl benzene anionic surfactants, amine oxides,
amphoteric surfactants, silicone based surfactants, alkoxylated
novolac resins (e.g. alkoxylated phenolic resins), alkoxylated
polyimines, alkoxylated polyamines, and fluorosurfactants. In some
embodiments, the surfactant is a nonionic surfactant. In certain
embodiments, the nonionic surfactant may be one or more of an
ethoxylated castor oil, an ethoxylated alcohol, an ethoxylated
tristyrylphenol, or an ethoxylated sorbitan ester, or combinations
thereof.
Co-Solvent
[0082] In some embodiments, an emulsion or microemulsion further
comprises at least one co-solvent. The co-solvent may serve as a
coupling agent between the one or more types of solvent and the
surfactant and/or may aid in the stabilization of the emulsion or
microemulsion. In some embodiments, the co-solvent is an alcohol.
The alcohol may also be a freezing point depression agent for the
emulsion or microemulsion. That is, the alcohol may lower the
freezing point of the emulsion or microemulsion. In some
embodiments, the alcohol is selected from primary, secondary, and
tertiary alcohols having from 1 to 6 carbon atoms.
[0083] In some embodiments, the emulsion or microemulsion comprises
a first type of co-solvent and second type of co-solvent. In some
embodiments, the first type of co-solvent is a small chain alcohol
(e.g., C.sub.1-6 alcohol such as isopropanol). In some embodiments,
the second type of co-solvent is an small chain alkylene glycol
(e.g., C.sub.1-7 alkylene glycol such as propylene glycol).
[0084] Non-limiting examples of co-solvents include methanol,
ethanol, isopropanol, n-propanol, n-butanol, i-butanol,
sec-butanol, iso-butanol, t-butanol, ethylene glycol, propylene
glycol, dipropylene glycol monomethyl ether, triethylene glycol,
and ethylene glycol monobutyl ether.
[0085] In some embodiments, the emulsion or microemulsion comprises
from about 1 wt % to about 50 wt %, or from about 1 wt % to about
40 wt %, or from about 1 wt % to about 35 wt %, or from about 5 wt
% to about 40 wt %, or from about 5 wt % to about 35 wt %, or from
about 10 wt % to about 30 wt % of the co-solvent (e.g., alcohol),
versus the total weight of the emulsion or microemulsion
composition.
[0086] In some embodiments, the emulsion or microemulsion comprises
from about 1 wt % and about 5 wt %, or from about 1 wt % and about
3 wt %, or about 2 wt % of the first type of co-solvent (e.g.,
C.sub.1-6 alcohol such as isopropanol) and from about 15 wt % and
about 25 wt %, or from about 17 wt % and about 22 wt % of the
second type of co-solvent (e.g., C.sub.1-7 alkylene glycol such as
propylene glycol).
Additives
[0087] In some embodiments, the emulsion or microemulsion may
comprise one or more additives in addition to the components
discussed above. In some embodiments, the one or more additional
additives are present in an amount from about 0 wt % to about 70 wt
%, or from about 1 wt % to about 40 wt %, or from about 0 wt % to
about 30 wt %, or from about 0.5 wt % to about 30 wt %, or from
about 1 wt % to about 30 wt %, or from about 0 wt % to about 25 wt
%, or from about 1 wt % to about 25 wt %, or from about 0 wt % to
about 20 wt %, or from about 1 wt % to about 20 wt %, or from about
3 wt % to about 20 wt %, or from about 8 wt % to about 16 wt %,
versus the total weight of the emulsion or microemulsion
composition.
[0088] Non-limiting examples of additives include a demulsifier, a
freezing point depression agent, a proppant, a scale inhibitor, a
friction reducer, a biocide, a corrosion inhibitor, a buffer, a
viscosifier, an oxygen scavenger, a clay control additive, a
paraffin control additive, an asphaltene control additive, an acid,
an acid precursor, or a salt.
[0089] In some embodiments, the additive is a demulsifier. The
demulsifier may aid in preventing the formulation of an emulsion
between a treatment fluid and crude oil. Non-limiting examples of
demulsifiers include polyoxyethylene (50) sorbitol hexaoleate. In
some embodiments, the demulsifier is present in the emulsion or
microemulsion in an amount from about 4 wt % to about 8 wt % versus
the total weight of the emulsion or microemulsion composition.
[0090] In some embodiments, the emulsion or the microemulsion
comprises a freezing point depression agent (e.g., propylene
glycol). The emulsion or the microemulsion may comprise a single
freezing point depression agent or a combination of two or more
freezing point depression agents. The term "freezing point
depression agent" is given its ordinary meaning in the art and
refers to a compound which is added to a solution to reduce the
freezing point of the solution. That is, in some embodiments, a
solution comprising the freezing point depression agent has a lower
freezing point as compared to an essentially identical solution not
comprising the freezing point depression agent. Those of ordinary
skill in the art will be aware of suitable freezing point
depression agents for use in the emulsions or the microemulsions
described herein. Non-limiting examples of freezing point
depression agents include primary, secondary, and tertiary alcohols
with from 1 to 20 carbon atoms and alkylene glycols. In some
embodiments, the alcohol comprises at least 2 carbon atoms.
Non-limiting examples of alcohols include methanol, ethanol,
i-propanol, n-propanol, t-butanol, n-butanol, n-pentanol,
n-hexanol, and 2-ethyl hexanol. In some embodiments, the freezing
point depression agent is not methanol (e.g., due to toxicity).
Non-limiting examples of alkylene glycols include ethylene glycol
(EG), polyethylene glycol (PEG), propylene glycol (PG), and
triethylene glycol (TEG). In some embodiments, the freezing point
depression agent is not ethylene oxide (e.g., due to toxicity). In
some embodiments, the freezing point depression agent comprises an
alcohol and an alkylene glycol. In some embodiments, the freezing
point depression agent comprises a carboxycyclic acid salt and/or a
di-carboxycylic acid salt. Another non-limiting example of a
freezing point depression agent is a combination of choline
chloride and urea. In some embodiments, the emulsion or
microemulsion comprising the freezing point depression agent is
stable over a wide range of temperatures, e.g., from about
50.degree. F. to 200.degree. F. In some embodiments a freezing
point depression agent is present in the emulsion or microemulsion
in an amount from about 10 wt % to about 15 wt %.
[0091] In some embodiments, the emulsion or the microemulsion
comprises a proppant. In some embodiments, the proppant acts to
hold induced hydraulic fractures open in an oil and/or gas well.
Non-limiting examples of proppants (e.g., propping agents) include
grains of sand, glass beads, crystalline silica (e.g., quartz),
hexamethylenetetramine, ceramic proppants (e.g., calcined clays),
resin coated sands, and resin coated ceramic proppants. Other
proppants are also possible and will be known to those skilled in
the art.
[0092] In some embodiments, the emulsion or the microemulsion
comprises a scale inhibitor. The scale inhibitor may slow scaling
in, e.g., the treatment of an oil and/or gas well, wherein scaling
involves the unwanted deposition of solids (e.g., along a pipeline)
that hinders fluid flow. Non-limiting examples of scale inhibitors
include one or more of methyl alcohol, organic phosphonic acid
salts (e.g., phosphonate salt, aminopolycarboxlic acid salts),
polyacrylate, ethane-1,2-diol, calcium chloride, and sodium
hydroxide. Other scale inhibitors are also possible and will be
known to those skilled in the art.
[0093] In some embodiments, the emulsion or the microemulsion
comprises a friction reducer. The friction reducer may reduce drag,
which reduces energy input required in the context of e.g.
delivering the emulsion or microemulsion into a wellbore.
Non-limiting examples of friction reducers include oil-external
emulsions of polymers with oil-based solvents and an
emulsion-stabilizing surfactant. The emulsions may include
natural-based polymers like guar, cellulose, xanthan, proteins,
polypeptides or derivatives of same or synthetic polymers like
polyacrylamide-co-acrylic acid (PAM-AA), polyethylene oxide,
polyacrylic acid, and other copolymers of acrylamide and other
vinyl monomers. For a list of non-limiting examples, see U.S. Pat.
No. 8,865,632, filed Nov. 10, 2008, entitled "DRAG-REDUCING
COPOLYMER COMPOSITION," herein incorporated by reference. Other
common drag-reducing additives include dispersions of natural- or
synthetic polymers and copolymers in saline solution and dry
natural- or synthetic polymers and copolymers. These polymers or
copolymers may be nonionic, zwitterionic, anionic, or cationic
depending on the composition of polymer and pH of solution. Other
non-limiting examples of friction reducers include petroleum
distillates, ammonium salts, polyethoxylated alcohol surfactants,
and anionic polyacrylamide copolymers. Other friction reducers are
also possible and will be known to those skilled in the art.
[0094] In some embodiments, the emulsion or the microemulsion
comprises a biocide. The biocide may kill unwanted organisms (e.g.,
microorganisms) that come into contact with the emulsion or
microemulsion. Non-limiting examples of biocides include didecyl
dimethyl ammonium chloride, gluteral, Dazomet, bronopol, tributyl
tetradecyl phosphonium chloride, tetrakis (hydroxymethyl)
phosphonium sulfate, AQUCAR.RTM., UCARCIDE.RTM., glutaraldehyde,
sodium hypochlorite, and sodium hydroxide. Other biocides are also
possible and will be known to those skilled in the art.
[0095] In some embodiments, the emulsion or the microemulsion
comprises a corrosion inhibitor. The corrosion inhibitor may reduce
corrosion during e.g. treatment of an oil and/or gas well (e.g., in
a metal pipeline). Non-limiting examples of corrosion inhibitors
include isopropanol, quaternary ammonium compounds,
thiourea/formaldehyde copolymers, propargyl alcohol, and methanol.
Other corrosion inhibitors are also possible and will be known to
those skilled in the art.
[0096] In some embodiments, the emulsion or the microemulsion
comprises a buffer. The buffer may maintain the pH and/or reduce
changes in the pH of the aqueous phase of the emulsion or the
microemulsion. Non-limiting examples of buffers include acetic
acid, acetic anhydride, potassium hydroxide, sodium hydroxide, and
sodium acetate. Other buffers are also possible and will be known
to those skilled in the art.
[0097] In some embodiments, the emulsion or the microemulsion
comprises a viscosifier. The viscosifier may increase the viscosity
of the emulsion or the microemulsion. Non-limiting examples of
viscosifiers include polymers, e.g., guar, cellulose, xanthan,
proteins, polypeptides or derivatives of same or synthetic polymers
like polyacrylamide-co-acrylic acid (PAM-AA), polyethylene oxide,
polyacrylic acid, and other copolymers of acrylamide and other
vinyl monomers. Other viscosifiers are also possible and will be
known to those skilled in the art.
[0098] In some embodiments, the emulsion or the microemulsion
comprises an oxygen scavenger. The oxygen scavenger may decrease
the level of oxygen in the emulsion or the microemulsion.
Non-limiting examples of oxygen scavengers include sulfites and
bisulfites. Other oxygen scavengers are also possible and will be
known to those skilled in the art.
[0099] In some embodiments, the emulsion or the microemulsion
comprises a clay control additive. The clay control additive may
minimize damaging effects of clay (e.g., swelling, migration),
e.g., during treatment of oil and/or gas wells. Non-limiting
examples of clay control additives include quaternary ammonium
chloride, tetramethylammonium chloride, polymers (e.g., polyanionic
cellulose (PAC), partially hydrolyzed polyacrylamide (PHPA), etc.),
glycols, sulfonated asphalt, lignite, sodium silicate, and choline
chloride. Other clay control additives are also possible and will
be known to those skilled in the art.
[0100] In some embodiments, the emulsion or the microemulsion
comprises a paraffin control additive and/or an asphaltene control
additive. The paraffin control additive or the asphaltene control
additive may minimize paraffin deposition or asphaltene
precipitation respectively in crude oil, e.g., during treatment of
oil and/or gas wells. Non-limiting examples of paraffin control
additives and asphaltene control additives include active acidic
copolymers, active alkylated polyester, active alkylated polyester
amides, active alkylated polyester imides, aromatic naphthas, and
active amine sulfonates. Other paraffin control additives and
asphaltene control additives are also possible and will be known to
those skilled in the art.
[0101] In some embodiments, the emulsion or the microemulsion
comprises an acid and/or an acid precursor (e.g., an ester). For
example, the emulsion or the microemulsion may comprise an acid
when used during acidizing operations. In some embodiments, the
surfactant is alkaline and an acid (e.g., hydrochloric acid) may be
used to adjust the pH of the emulsion or the microemulsion towards
neutral. Non-limiting examples of acids or di-acids include
hydrochloric acid, acetic acid, formic acid, succinic acid, maleic
acid, malic acid, lactic acid, and hydrochloric-hydrofluoric acids.
In some embodiments, the emulsion or the microemulsion comprises an
organic acid or organic di-acid in the ester (or di-ester) form,
whereby the ester (or diester) is hydrolyzed in the wellbore and/or
reservoir to form the parent organic acid and an alcohol in the
wellbore and/or reservoir. Non-limiting examples of esters or
di-esters include isomers of methyl formate, ethyl formate,
ethylene glycol diformate,
alpha,alpha-4-trimethyl-3-cyclohexene-1-methylformate, methyl
lactate, ethyl lactate, alpha,alpha-4-trimethyl
3-cyclohexene-1-methyllactate, ethylene glycol dilactate, ethylene
glycol diacetate, methyl acetate, ethyl acetate,
alpha,alpha-4-trimethyl-3-cyclohexene-1-methylacetate, dimethyl
succinate, dimethyl maleate,
di(alpha,alpha-4-trimethyl-3-cyclohexene-1-methyl)-succinate,
1-methyl-4-(1-methylethenyl)-cyclohexylformate,
1-methyl-4-(1-ethylethenyl)-cyclohexylactate,
1-methyl-4-(1-methylethenyl)-cyclohexylacetate, and
di(1-methy-4-(1-methylethenyl)cyclohexyl)-succinate. Other acids
are also possible and will be known to those skilled in the
art.
In some embodiments, the emulsion or the microemulsion comprises a
salt. The salt may reduce the amount of water needed as a carrier
fluid and/or may lower the freezing point of the emulsion or the
microemulsion. Non limiting examples of salts include salts
comprising K, Na, Br, Cr, Cs, or Li, e.g., halides of these metals,
including but not limited to NaCl, KCl, CaCl.sub.2, and MgCl.sub.2.
Other salts are also possible and will be known to those skilled in
the art.
[0102] In some embodiments, the emulsion or the microemulsion
comprises an additive as described in U.S. patent application Ser.
No. 15/457,792, filed Mar. 13, 2017, entitled "METHODS AND
COMPOSITIONS INCORPORATING ALKYL POLYGLYCOSIDE SURFACTANT FOR USE
IN OIL AND/OR GAS WELLS," published as US 2017-0275518 on Sep. 28,
2017, herein incorporated by reference.
Methods
[0103] The emulsions or microemulsions described herein may be
formed using methods known to those of ordinary skill in the art.
In some embodiments, the aqueous and non-aqueous phases may be
combined (e.g., the water and the solvent(s)), followed by addition
of a surfactant(s) and optionally a co-solvent(s) (e.g.,
alcohol(s)) and agitation). Other orders of addition/combining are
possible. The strength, type, and length of the agitation may be
varied as known in the art depending on various factors including
the components of the emulsion or microemulsion, the quantity of
the emulsion or microemulsion, and the resulting type of emulsion
or microemulsion formed. For example, for small samples, a few
seconds of gentle mixing can yield an emulsion or microemulsion,
whereas for larger samples, longer agitation times and/or stronger
agitation may be required. Agitation may be provided by any
suitable source, e.g., a vortex mixer, a stirrer (e.g., magnetic
stirrer), etc.
[0104] Any suitable method for injecting the emulsion or
microemulsion (e.g., a diluted emulsion or microemulsion) into a
wellbore may be employed. For example, in some embodiments, the
emulsion or microemulsion, optionally diluted, may be injected into
a subterranean formation by injecting it into a well or wellbore in
the zone of interest of the formation and thereafter pressurizing
it into the formation for the selected distance. Methods for
achieving the placement of a selected quantity of a mixture in a
subterranean formation are known in the art. The well may be
treated with the emulsion or microemulsion for a suitable period of
time. The emulsion or microemulsion and/or other fluids may be
removed from the well using known techniques, including producing
the well.
[0105] It should be understood, that in embodiments where an
emulsion or microemulsion is said to be injected into a wellbore,
that the emulsion or microemulsion may be diluted and/or combined
with other liquid component(s) prior to and/or during injection
(e.g., via straight tubing, via coiled tubing, etc.). For example,
in some embodiments, the emulsion or microemulsion is diluted with
an aqueous carrier fluid (e.g., water, brine, sea water, fresh
water, or a well-treatment fluid (e.g., an acid, a fracturing fluid
comprising polymers, produced water, sand, slickwater, etc.,) prior
to and/or during injection into the wellbore. In some embodiments,
a composition for injecting into a wellbore is provided comprising
an emulsion or microemulsion as described herein and an aqueous
carrier fluid, wherein the emulsion or microemulsion is present in
an amount from about 0.1 gallons per thousand gallons (gpt) per
dilution fluid to about 50 gpt, or from about 0.1 gpt to about 100
gpt, or from about 0.5 gpt to about 10 gpt, or from about 0.5 gpt
to about 2 gpt.
[0106] The emulsions and microemulsions described herein may be
used in various aspects (e.g. steps) of the life cycle of an oil
and/or gas well, including, but not limited to, drilling, mud
displacement, casing, cementing, perforating, stimulation, kill
fluids, enhanced oil recovery, improved oil recovery, stored fluid,
and offshore applications. Inclusion of an emulsion or
microemulsion into the fluids typically employed in these
processes, e.g., drilling fluids, mud displacement fluids, casing
fluids, cementing fluids, perforating fluid, stimulation fluids,
kill fluids, etc., may result in many advantages as compared to use
of the fluid alone.
[0107] Various aspects of the well life cycle are described in
detail in U.S. patent application Ser. No. 14/212,731, filed Mar.
14, 2014, entitled "METHODS AND COMPOSITIONS FOR USE IN OIL AND/OR
GAS WELLS," now published as US/2014/0284053 on Sep. 25, 2014 and
in U.S. patent application Ser. No. 14/212,763, filed Mar. 14,
2014, entitled "METHODS AND COMPOSITIONS FOR USE IN OIL AND/OR GAS
WELLS," now published as US/2014/0338911 on Nov. 20, 2014, each
herein incorporated by reference.
[0108] As will be understood by those of ordinary skill in the art,
the steps of the life cycle of an oil and/or gas well may be
carried out in a variety of orders. In addition, in some
embodiments, each step may occur more than once in the life cycle
of the well.
Definitions
[0109] For convenience, certain terms employed in the
specification, examples, and appended claims are listed here.
[0110] As used herein, the term emulsion is given its ordinary
meaning in the art and refers to dispersions of one immiscible
liquid in another, in the form of droplets, with diameters
approximately in the range of 100-1,000 nanometers. Emulsions may
be thermodynamically unstable and/or require high shear forces to
induce their formation.
[0111] As used herein, the term microemulsion is given its ordinary
meaning in the art and refers to dispersions of one immiscible
liquid in another, in the form of droplets, with diameters
approximately in the range of about from about 1 nanometers (nm) to
about 1000 nm, or from about 10 nm to about 1000 nm, or from about
10 nm to about 500 nm, or from about 10 nm to about 300 nm, or from
about 10 nm to about 100 nm.
[0112] In some embodiments, microemulsions are clear or transparent
because they contain particles smaller than the wavelength of
visible light. In addition, microemulsions are homogeneous
thermodynamically stable single phases, and form spontaneously, and
thus, differ markedly from thermodynamically unstable emulsions,
which generally depend upon intense mixing energy for their
formation. Microemulsions may be characterized by a variety of
advantageous properties including, by not limited to, (i) clarity,
(ii) very small particle size, (iii) ultra-low interfacial
tensions, (iv) the ability to combine properties of water and oil
in a single homogeneous fluid, (v) shelf life stability, and (vi)
ease of preparation.
[0113] In some embodiments, the microemulsions described herein are
stabilized microemulsions that are formed by the combination of a
solvent-surfactant blend with an appropriate oil-based or
water-based carrier fluid. Generally, the microemulsion forms upon
simple mixing of the components without the need for high shearing
generally required in the formation of ordinary emulsions. In some
embodiments, the microemulsion is a thermodynamically stable
system, and the droplets remain finely dispersed over time. In some
embodiments, the average droplet size ranges from about 10 nm to
about 300 nm.
[0114] It should be understood that the description herein which
focuses on microemulsions is by no means limiting, and emulsions
may be employed where appropriate.
[0115] In some embodiments, the emulsion or microemulsion is a
single emulsion or microemulsion. For example, the emulsion or
microemulsion comprises a single layer of a surfactant. In other
embodiments, the emulsion or microemulsion may be a double or
multilamellar emulsion or microemulsion. For example, the emulsion
or microemulsion comprises two or more layers of a surfactant. In
some embodiments, the emulsion or microemulsion comprises a single
layer of surfactant surrounding a core (e.g., one or more of water,
oil, solvent, and/or other additives) or a multiple layers of
surfactant (e.g., two or more concentric layers surrounding the
core). In certain embodiments, the emulsion or microemulsion
comprises two or more immiscible cores (e.g., one or more of water,
oil, solvent, and/or other additives which have equal or about
equal affinities for the surfactant).
[0116] The term "emulsion" is given its ordinary meaning in the art
and generally refers to a thermodynamically stable dispersion of
water-in-oil or oil-in-water wherein in some embodiments (e.g., in
the case of a macroemulsion) the interior phase is in the form of
visually discernable droplets and the overall emulsion is cloudy,
and wherein the droplet diameter may in some embodiments (e.g., in
the case of a macroemulsion) be greater than about 300 nm.
[0117] The term "microemulsion" is given its ordinary meaning in
the art and generally refers to a thermodynamically stable
dispersion of water and oil that forms spontaneously upon mixture
of oil, water and various surfactants. Microemulsion droplets
generally have a mean diameter of less than 300 nm. Because
microemulsion droplets are smaller than the wavelength of visible
light, solutions comprising them are generally translucent or
transparent, unless there are other components present that
interfere with passage of visible light. In some embodiments, a
microemulsion is substantially homogeneous. In other embodiments,
microemulsion particles may co-exist with other surfactant-mediated
systems, e.g., micelles, hydrosols, and/or macroemulsions. In some
embodiments, the microemulsions of the present invention are
oil-in-water microemulsions. In some embodiments, the majority of
the oil component, e.g., (in various embodiments, greater than
about 50%, greater than about 75%, or greater than about 90%), is
located in microemulsion droplets rather than in micelles or
macroemulsion droplets. In various embodiments, the microemulsions
of the invention are clear or substantially clear.
[0118] The conventional terms water-in-oil and oil-in-water,
whether referring to macroemulsions, emulsions, or microemulsions,
simply describe systems that are water-discontinuous and
water-continuous, respectively. They do not denote any additional
restrictions on the range of substances denoted as "oil".
[0119] The terms "clear" or "transparent" as applied to a
microemulsion are given its ordinary meaning in the art and
generally refers to the microemulsion appearing as a single phase
without any particulate or colloidal material or a second phase
being present when viewed by the naked eye.
[0120] Definitions of specific functional groups and chemical terms
are described in more detail below. For purposes of this invention,
the chemical elements are identified in accordance with the
Periodic Table of the Elements, CAS version, Handbook of Chemistry
and Physics, 75.sup.th Ed., inside cover, and specific functional
groups are generally defined as described therein. Additionally,
general principles of organic chemistry, as well as specific
functional moieties and reactivity, are described in Organic
Chemistry, Thomas Sorrell, University Science Books, Sausalito:
1999, the entire contents of which are incorporated herein by
reference.
[0121] Certain compounds of the present invention may exist in
particular geometric or stereoisomeric forms. The present invention
contemplates all such compounds, including cis- and trans-isomers,
R- and S-enantiomers, diastereomers, (D)-isomers, (L)-isomers, the
racemic mixtures thereof, and other mixtures thereof, as falling
within the scope of the invention. Additional asymmetric carbon
atoms may be present in a substituent such as an alkyl group. All
such isomers, as well as mixtures thereof, are intended to be
included in this invention.
[0122] Isomeric mixtures containing any of a variety of isomer
ratios may be utilized in accordance with the present invention.
For example, where only two isomers are combined, mixtures
containing 50:50, 60:40, 70:30, 80:20, 90:10, 95:5, 96:4, 97:3,
98:2, 99:1, or 100:0 isomer ratios are all contemplated by the
present invention. Those of ordinary skill in the art will readily
appreciate that analogous ratios are contemplated for more complex
isomer mixtures.
[0123] The term "aliphatic," as used herein, includes both
saturated and unsaturated, nonaromatic, straight chain (i.e.,
unbranched), branched, acyclic, and cyclic (i.e., carbocyclic)
hydrocarbons, which are optionally substituted with one or more
functional groups. As will be appreciated by one of ordinary skill
in the art, "aliphatic" is intended herein to include, but is not
limited to, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, and
cycloalkynyl moieties. Thus, as used herein, the term "alkyl"
includes straight, branched and cyclic alkyl groups. An analogous
convention applies to other generic terms such as "alkenyl",
"alkynyl", and the like. Furthermore, as used herein, the terms
"alkyl", "alkenyl", "alkynyl", and the like encompass both
substituted and unsubstituted groups. In certain embodiments, as
used herein, "aliphatic" is used to indicate those aliphatic groups
(cyclic, acyclic, substituted, unsubstituted, branched or
unbranched) having 1 to 20 carbon atoms. Aliphatic group
substituents include, but are not limited to, any of the
substituents described herein, that result in the formation of a
stable moiety (e.g., aliphatic, alkyl, alkenyl, alkynyl,
heteroaliphatic, heterocyclic, aryl, heteroaryl, acyl, oxo, imino,
thiooxo, cyano, isocyano, amino, azido, nitro, hydroxyl, thiol,
halo, aliphaticamino, heteroaliphaticamino, alkylamino,
heteroalkylamino, arylamino, heteroarylamino, alkylaryl, arylalkyl,
aliphaticoxy, heteroaliphaticoxy, alkyloxy, heteroalkyloxy,
aryloxy, heteroaryloxy, aliphaticthioxy, heteroaliphaticthioxy,
alkylthioxy, heteroalkylthioxy, arylthioxy, heteroarylthioxy,
acyloxy, and the like, each of which may or may not be further
substituted).
[0124] As used herein, the term "alkyl" is given its ordinary
meaning in the art and refers to the radical of saturated aliphatic
groups, including straight chain alkyl groups, branched-chain alkyl
groups, cycloalkyl (alicyclic) groups, alkyl substituted cycloalkyl
groups, and cycloalkyl substituted alkyl groups. In some
embodiments, the alkyl group may be a lower alkyl group, e.g., an
alkyl group having 1 to 10 carbon atoms (e.g., methyl, ethyl,
propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, or decyl). In
some embodiments, a straight chain or branched chain alkyl may have
30 or fewer carbon atoms in its backbone, and, in some embodiments,
20 or fewer. In some embodiments, a straight chain or branched
chain alkyl may have 12 or fewer carbon atoms in its backbone
(e.g., C.sub.1-C.sub.12 for straight chain, C.sub.3-C.sub.12 for
branched chain), 6 or fewer, or 4 or fewer. Likewise, cycloalkyls
may have from 3 to 10 carbon atoms in their ring structure, or 5, 6
or 7 carbon atoms in their ring structure. Examples of alkyl groups
include, but are not limited to, methyl, ethyl, propyl, isopropyl,
cyclopropyl, butyl, isobutyl, t-butyl, cyclobutyl, hexyl, and
cyclochexyl.
[0125] The term "heteroalkyl" is given its ordinary meaning in the
art and refers to an alkyl group as described herein in which one
or more carbon atoms is replaced by a heteroatom. Suitable
heteroatoms include oxygen, sulfur, nitrogen, phosphorus, and the
like. Examples of heteroalkyl groups include, but are not limited
to, alkoxy, alkoxyalkyl, amino, thioester, poly(ethylene glycol),
and alkyl-substituted amino.
[0126] The terms "alkenyl" and "alkynyl" are given their ordinary
meaning in the art and refer to unsaturated aliphatic groups
analogous in length and possible substitution to the alkyls
described above, but that contain at least one double or triple
bond respectively.
[0127] In certain embodiments, the alkyl, alkenyl and alkynyl
groups employed in the invention contain 1 to 20 aliphatic carbon
atoms. In certain other embodiments, the alkyl, alkenyl, and
alkynyl groups employed in the invention contain 1 to 10 aliphatic
carbon atoms. In yet other embodiments, the alkyl, alkenyl, and
alkynyl groups employed in the invention contain 1 to 8 aliphatic
carbon atoms. In still other embodiments, the alkyl, alkenyl, and
alkynyl groups employed in the invention contain 1 to 6 aliphatic
carbon atoms. In yet other embodiments, the alkyl, alkenyl, and
alkynyl groups employed in the invention contain 1 to 4 carbon
atoms. Illustrative aliphatic groups thus include, but are not
limited to, for example, methyl, ethyl, n-propyl, isopropyl, allyl,
n-butyl, sec-butyl, isobutyl, t-butyl, n-pentyl, sec-pentyl,
isopentyl, t-pentyl, n-hexyl, sec-hexyl, moieties and the like,
which again, may bear one or more substituents. Alkenyl groups
include, but are not limited to, for example, ethenyl, propenyl,
butenyl, 1-methyl-2-buten-1-yl, and the like. Representative
alkynyl groups include, but are not limited to, ethynyl, 2-propynyl
(propargyl), 1-propynyl and the like.
[0128] The term "cycloalkyl," as used herein, refers specifically
to groups having three to ten, preferably three to seven carbon
atoms. Suitable cycloalkyls include, but are not limited to
cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and
the like, which, as in the case of other aliphatic,
heteroaliphatic, or hetercyclic moieties, may optionally be
substituted with substituents including, but not limited to
aliphatic; heteroaliphatic; aryl; heteroaryl; arylalkyl;
heteroarylalkyl; alkoxy; aryloxy; heteroalkoxy; heteroaryloxy;
alkylthio; arylthio; heteroalkylthio; heteroarylthio; --F; --Cl;
--Br; --I; --OH; --NO.sub.2; --CN; --CF.sub.3; --CH.sub.2CF.sub.3;
--CHCl.sub.2; --CH.sub.2OH; --CH.sub.2CH.sub.2OH;
--CH.sub.2NH.sub.2; --CH.sub.2SO.sub.2CH.sub.3; --C(O)R.sup.x;
--CO.sub.2(R.sup.x); --CON(R.sup.x).sub.2; --OC(O)R.sup.x;
--OCO.sub.2R.sup.x; --OCON(R.sup.x).sub.2; --N(R.sup.x).sub.2;
--S(O).sub.2R.sup.x; --NR.sup.x(CO)R.sup.x, wherein each occurrence
of R.sup.x independently includes, but is not limited to,
aliphatic, heteroaliphatic, aryl, heteroaryl, arylalkyl, or
heteroarylalkyl, wherein any of the aliphatic, heteroaliphatic,
arylalkyl, or heteroarylalkyl substituents described above and
herein may be substituted or unsubstituted, branched or unbranched,
cyclic or acyclic, and wherein any of the aryl or heteroaryl
substituents described above and herein may be substituted or
unsubstituted. Additional examples of generally applicable
substituents are illustrated by the specific embodiments shown in
the examples that are described herein.
[0129] As used herein, the term "aromatic" is given its ordinary
meaning in the art and refers to aromatic carbocyclic groups,
having a single ring (e.g., phenyl), multiple rings (e.g.,
biphenyl), or multiple fused rings in which at least one is
aromatic (e.g., 1,2,3,4-tetrahydronaphthyl, naphthyl, anthryl, or
phenanthryl). That is, at least one ring may have a conjugated pi
electron system, while other, adjoining rings can be cycloalkyls,
cycloalkenyls, cycloalkynyls, aryls and/or heterocyclyls. The term
aromatic encompasses aryl and heteroaryl.
[0130] As used herein, the term "aryl" is given its ordinary
meaning in the art and refers to aromatic carbocyclic groups,
optionally substituted, having a single ring (e.g., phenyl),
multiple rings (e.g., biphenyl), or multiple fused rings in which
at least one is aromatic (e.g., 1,2,3,4-tetrahydronaphthyl,
naphthyl, anthryl, or phenanthryl). That is, at least one ring may
have a conjugated pi electron system, while other, adjoining rings
can be cycloalkyls, cycloalkenyls, cycloalkynyls, aryls and/or
heterocyclyls. The aryl group may be optionally substituted, as
described herein. Substituents include, but are not limited to, any
of the previously mentioned substituents, e.g., the substituents
recited for aliphatic moieties, or for other moieties as disclosed
herein, resulting in the formation of a stable compound. In some
embodiments, an aryl group is a stable monocyclic or polycyclic
unsaturated moiety having preferably 3 to 14 carbon atoms, each of
which may be substituted or unsubstituted.
[0131] The term "heterocycle" is given its ordinary meaning in the
art and refers to cyclic groups containing at least one heteroatom
as a ring atom, in some embodiments, 1 to 3 heteroatoms as ring
atoms, with the remainder of the ring atoms being carbon atoms.
Suitable heteroatoms include oxygen, sulfur, nitrogen, phosphorus,
and the like. In some embodiments, the heterocycle may be
3-membered to 10-membered ring structures or 3-membered to
7-membered rings, whose ring structures include one to four
heteroatoms.
[0132] The term "heteroaryl" is given its ordinary meaning in the
art and refers to aryl groups comprising at least one heteroatom as
a ring atom. A "heteroaryl" is a stable heterocyclic or
polyheterocyclic unsaturated moiety having preferably 3 to 14
carbon atoms, each of which may be substituted or unsubstituted.
Substituents include, but are not limited to, any of the previously
mentioned substituents, e.g., the substituents recited for
aliphatic moieties, or for other moieties as disclosed herein,
resulting in the formation of a stable compound. In some
embodiments, a heteroaryl is a cyclic aromatic radical having from
five to ten ring atoms of which one ring atom is selected from S,
O, and N; zero, one, or two ring atoms are additional heteroatoms
independently selected from S, O, and N; and the remaining ring
atoms are carbon, the radical being joined to the rest of the
molecule via any of the ring atoms, such as, e.g., pyridyl,
pyrazinyl, pyrimidinyl, pyrrolyl, pyrazolyl, imidazolyl, thiazolyl,
oxazolyl, isooxazolyl, thiadiazolyl, oxadiazolyl, thiophenyl,
furanyl, quinolinyl, isoquinolinyl, and the like.
[0133] It will be appreciated that the above groups and/or
compounds, as described herein, may be optionally substituted with
any number of substituents or functional moieties. That is, any of
the above groups may be optionally substituted. As used herein, the
term "substituted" is contemplated to include all permissible
substituents of organic compounds, "permissible" being in the
context of the chemical rules of valence known to those of ordinary
skill in the art. In general, the term "substituted" whether
preceded by the term "optionally" or not, and substituents
contained in formulas of this invention, refer to the replacement
of hydrogen radicals in a given structure with the radical of a
specified substituent. When more than one position in any given
structure may be substituted with more than one substituent
selected from a specified group, the substituent may be either the
same or different at every position. It will be understood that
"substituted" also includes that the substitution results in a
stable compound, e.g., which does not spontaneously undergo
transformation such as by rearrangement, cyclization, elimination,
etc. In some embodiments, "substituted" may generally refer to
replacement of a hydrogen with a substituent as described herein.
However, "substituted," as used herein, does not encompass
replacement and/or alteration of a key functional group by which a
molecule is identified, e.g., such that the "substituted"
functional group becomes, through substitution, a different
functional group. For example, a "substituted phenyl group" must
still comprise the phenyl moiety and cannot be modified by
substitution, in this definition, to become, e.g., a pyridine ring.
In a broad aspect, the permissible substituents include acyclic and
cyclic, branched and unbranched, carbocyclic and heterocyclic,
aromatic and nonaromatic substituents of organic compounds.
Illustrative substituents include, for example, those described
herein. The permissible substituents can be one or more and the
same or different for appropriate organic compounds. For purposes
of this invention, the heteroatoms such as nitrogen may have
hydrogen substituents and/or any permissible substituents of
organic compounds described herein which satisfy the valencies of
the heteroatoms. Furthermore, this invention is not intended to be
limited in any manner by the permissible substituents of organic
compounds. Combinations of substituents and variables envisioned by
this invention are preferably those that result in the formation of
stable compounds useful for the formation of an imaging agent or an
imaging agent precursor.
[0134] The term "stable," as used herein, preferably refers to
compounds which possess stability sufficient to allow manufacture
and which maintain the integrity of the compound for a sufficient
period of time to be detected and preferably for a sufficient
period of time to be useful for the purposes detailed herein.
EXAMPLES
[0135] These and other aspects of the present invention will be
further appreciated upon consideration of the following Examples,
which are intended to illustrate certain particular embodiments of
the invention but are not intended to limit its scope, as defined
by the claims.
Example 1
[0136] As set forth in Table 1 below, a series of laboratory
experiments (Experiment #1 through #8) were conducted to observed
whether a microemulsion forms at 25.degree. C., when using long
chain solvents, namely aliphatic mineral spirts having 12-18 carbon
atoms, in combination with oxygenated solvents (e.g. isooctanol).
Samples were prepared by mixing 16 wt % ethoxylated nonionic
surfactant with each of the other components as set forth in Table
7, and then balanced to 100 wt % water. Each sample was
characterized as a microemulsion if upon minimal amounts of
low-shear mixing, the sample formed a visually clear, homogenous,
stable, single phase at 25.degree. C.
TABLE-US-00001 TABLE 1 Long Chain Aliphatic Mineral Spirits with
Oxygenated Solvent (Isooctanol) Aliphatic Mineral Spirits Micro-
Exper- Isopro- (C.sub.12-C.sub.18 Propylene emulsion iment panol
blend) Isooctanol Glycol Formed at # (wt %) (wt %) (wt %) (wt %)
25.degree. C. 1 2.0 2.2 2.8 18.0 No 2 2.0 2.2 2.3 18.5 No 3 2.0 2.2
1.8 19.0 Yes 4 2.0 2.2 0.8 20 No 5 2.5 1.6 1.6 18.7 Yes 6 2.5 2.2
1.6 18.7 Yes 7 2.5 0 1.6 20.9 No 8 2.5 2.2 0 20.3 No
[0137] In Experiment #2, no microemulsion was formed at 25.degree.
C. when using a combination of 2.2 wt % aliphatic mineral spirits
and 2.3 wt % isooctanol. However, as shown in Experiment #3, by
using 2.2 wt % aliphatic mineral spirits and decreasing the
isooctanol to 1.8 wt. %, a microemulsion was formed at 25.degree.
C. Further, the microemulsion formed in Experiment #3 was
determined to be stable for a wide temperature range of from about
15.degree. F. (-9.4.degree. C.) to about 125.degree. F.
(51.7.degree. C.).
[0138] As discussed above in Experiment #3, a microemulsion was
formed. However as shown in Experiment #4, which comprises 2.2 wt %
aliphatic mineral spirts and 0.8 wt % oxygenated solvent (i.e.
isooctanol), no microemulsion was formed.
[0139] Experiment #5, which comprises 1.6 wt % aliphatic mineral
spirits and 1.6 wt % oxygenated solvent (i.e. isooctanol), a
microemulsion formed. Further, the microemulsion formed in
Experiment #5 was tested and determined to be stable for a wide
temperature range of from about 15.degree. F. (-9.4.degree. C.) to
about 125.degree. F. (51.7.degree. C.).
[0140] In Experiment #6, which comprises 2.2 wt % of aliphatic
mineral spirits and 1.6 wt % oxygenated solvent (i.e. isooctanol),
a microemulsion formed. Further, the microemulsion formed in
Experiment #6 was tested and determined to be stable for a wide
temperature range of from about 15.degree. F. (-9.4.degree. C.) to
about 125.degree. F. (51.7.degree. C.). As is evidenced in
Experiment #6, not just any ratio of aliphatic mineral spirit to
oxygenated solvent will result in the formation of a
microemulsion.
[0141] A person of ordinary skill in the art would not expect that
a composition comprising a solvent having long chain lengths would
form a microemulsion that is stable for a wide range of
temperatures from about 15.degree. F. (-9.4.degree. C.) to about
125.degree. F. (51.7.degree. C.) as shown in Experiment #3, #5, and
#6.
[0142] While several embodiments of the present invention have been
described and illustrated herein, those of ordinary skill in the
art will readily envision a variety of other means and/or
structures for performing the functions and/or obtaining the
results and/or one or more of the advantages described herein, and
each of such variations and/or modifications is deemed to be within
the scope of the present invention. More generally, those skilled
in the art will readily appreciate that all parameters, dimensions,
materials, and configurations described herein are meant to be
exemplary and that the actual parameters, dimensions, materials,
and/or configurations will depend upon the specific application or
applications for which the teachings of the present invention
is/are used. Those skilled in the art will recognize, or be able to
ascertain using no more than routine experimentation, many
equivalents to the specific embodiments of the invention described
herein. It is, therefore, to be understood that the foregoing
embodiments are presented by way of example only and that, within
the scope of the appended claims and equivalents thereto, the
invention may be practiced otherwise than as specifically described
and claimed. The present invention is directed to each individual
feature, system, article, material, kit, and/or method described
herein. In addition, any combination of two or more such features,
systems, articles, materials, kits, and/or methods, if such
features, systems, articles, materials, kits, and/or methods are
not mutually inconsistent, is included within the scope of the
present invention.
[0143] The indefinite articles "a" and "an," as used herein in the
specification and in the claims, unless clearly indicated to the
contrary, should be understood to mean "at least one."
[0144] The phrase "and/or," as used herein in the specification and
in the claims, should be understood to mean "either or both" of the
elements so conjoined, e.g. elements that are conjunctively present
in some cases and disjunctively present in other cases. Other
elements may optionally be present other than the elements
specifically identified by the "and/or" clause, whether related or
unrelated to those elements specifically identified unless clearly
indicated to the contrary. Thus, as a non-limiting example, a
reference to "A and/or B," when used in conjunction with open-ended
language such as "comprising" can refer, in one embodiment, to A
without B (optionally including elements other than B); in another
embodiment, to B without A (optionally including elements other
than A); in yet another embodiment, to both A and B (optionally
including other elements); etc.
[0145] As used herein in the specification and in the claims, "or"
should be understood to have the same meaning as "and/or" as
defined above. For example, when separating items in a list, "or"
or "and/or" shall be interpreted as being inclusive, e.g. the
inclusion of at least one, but also including more than one, of a
number or list of elements, and, optionally, additional unlisted
items. Only terms clearly indicated to the contrary, such as "only
one of" or "exactly one of," or, when used in the claims,
"consisting of," will refer to the inclusion of exactly one element
or a list of elements. In general, the term "or" as used herein
shall only be interpreted as indicating exclusive alternatives
(e.g. "one or the other but not both") when preceded by terms of
exclusivity, such as "either," "one of," "only one of," or "exactly
one of." "Consisting essentially of," when used in the claims,
shall have its ordinary meaning as used in the field of patent
law.
[0146] As used herein in the specification and in the claims, the
phrase "between" in reference to a range of elements or a range of
units should be understood to include the lower and upper range of
the elements or the lower and upper range of the units,
respectively. For example, the phrase describing a molecule having
"between 6 to 12 carbon atoms" should mean a molecule that may
have, e.g., from 6 carbon atoms to 12 carbon atoms, inclusively.
For example, the phrase describing a composition comprising
"between about 5 wt % and about 40 wt % surfactant" should mean the
composition may have, e.g., from about 5 wt % to about 40 wt %
surfactant, inclusively.
[0147] As used herein in the specification and in the claims, the
phrase "at least one," in reference to a list of one or more
elements, should be understood to mean at least one element
selected from any one or more of the elements in the list of
elements, but not necessarily including at least one of each and
every element specifically listed within the list of elements and
not excluding any combinations of elements in the list of elements.
This definition also allows that elements may optionally be present
other than the elements specifically identified within the list of
elements to which the phrase "at least one" refers, whether related
or unrelated to those elements specifically identified. Thus, as a
non-limiting example, "at least one of A and B" (or, equivalently,
"at least one of A or B," or, equivalently "at least one of A
and/or B") can refer, in one embodiment, to at least one,
optionally including more than one, A, with no B present (and
optionally including elements other than B); in another embodiment,
to at least one, optionally including more than one, B, with no A
present (and optionally including elements other than A); in yet
another embodiment, to at least one, optionally including more than
one, A, and at least one, optionally including more than one, B
(and optionally including other elements); etc.
[0148] In the claims, as well as in the specification above, all
transitional phrases such as "comprising," "including," "carrying,"
"having," "containing," "involving," "holding," and the like are to
be understood to be open-ended, e.g. to mean including but not
limited to. Only the transitional phrases "consisting of" and
"consisting essentially of" shall be closed or semi-closed
transitional phrases, respectively, as set forth in the United
States Patent Office Manual of Patent Examining Procedures, Section
2111.03.
* * * * *