U.S. patent application number 13/857932 was filed with the patent office on 2014-09-11 for multi-purpose paraffin additives for deposit control, anti-settling and wax softening in oil-based fluids.
This patent application is currently assigned to Baker Hughes Incorporated. The applicant listed for this patent is Baker Hughes Incorporated. Invention is credited to Paul J. Biggerstaff, Thomas J. Falkler, Waynn C. Morgan.
Application Number | 20140250771 13/857932 |
Document ID | / |
Family ID | 51486040 |
Filed Date | 2014-09-11 |
United States Patent
Application |
20140250771 |
Kind Code |
A1 |
Biggerstaff; Paul J. ; et
al. |
September 11, 2014 |
Multi-Purpose Paraffin Additives for Deposit Control, Anti-Settling
and Wax Softening in Oil-Based Fluids
Abstract
An additive may be added to an oil-based fluid having at least
one wax foulant therein. The additive may be or include an alpha
olefin copolymer, an alkyl phenol-formaldehyde resin, an alkyl
acrylate, a polyalkyl methacrylate, ethylene vinyl acetate
co-polymer, ethylene vinyl acetate terpolymer, imidazoline, and
combinations thereof. The additive may alter at least one property
of the wax foulant as compared to an otherwise identical oil-based
fluid absent the additive. The altered property may be or include
the amount of wax foulant deposited, the amount of paraffinic wax
dispersed, settling rate of the paraffinic wax foulant, viscosity
of the paraffinic wax foulant, shape of the paraffinic wax foulant,
such as but not limited to softening the wax foulant, and
combinations thereof.
Inventors: |
Biggerstaff; Paul J.; (Sugar
Land, TX) ; Morgan; Waynn C.; (Alvin, TX) ;
Falkler; Thomas J.; (Missouri City, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Baker Hughes Incorporated; |
|
|
US |
|
|
Assignee: |
Baker Hughes Incorporated
Huston
TX
|
Family ID: |
51486040 |
Appl. No.: |
13/857932 |
Filed: |
April 5, 2013 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
13786674 |
Mar 6, 2013 |
|
|
|
13857932 |
|
|
|
|
Current U.S.
Class: |
44/351 |
Current CPC
Class: |
C10L 1/1966 20130101;
C10G 75/04 20130101; C10G 2300/1062 20130101; C10L 10/14 20130101;
C10L 1/1963 20130101; C10L 1/196 20130101; C10L 1/1955 20130101;
C10G 2400/10 20130101; C10L 1/1641 20130101; C10L 1/192
20130101 |
Class at
Publication: |
44/351 |
International
Class: |
C10L 1/19 20060101
C10L001/19; C10L 1/185 20060101 C10L001/185 |
Claims
1-11. (canceled)
12. A method for improving at least one property of at least one
wax foulant within an oil-based fluid, the method comprising:
adding an effective amount of an additive to improve at least one
property of the at least one wax foulant, where the additive is
selected from the group consisting of an alpha olefin copolymer, an
alkyl phenol-formaldehyde resin, an alkyl acrylate, a polyalkyl
methacrylate, ethylene vinyl acetate co-polymer, ethylene vinyl
acetate terpolymer, imidazoline, and combinations thereof; and
wherein the at least one property is selected from the group
consisting of the amount of wax foulant deposited, the amount of
wax foulant dispersed, settling rate of the wax foulant, viscosity
of the wax foulant, shape of the wax foulant, and combinations
thereof.
13. The method of claim 12, wherein the effective amount of the
additive ranges from about 10 ppm to about 10000 ppm.
14. The method of claim 12, wherein the alpha olefin copolymer is
selected from the group consisting of alpha olefin maleic anhydride
copolymers, esters of alpha-olefin maleic anhydride copolymers,
imides of alpha-olefin maleic anhydride copolymers, and
combinations thereof.
15. The method of claim 14, wherein the alpha olefin copolymer has
a ratio based on weight of alpha-olefin to maleic anhydride ranging
from [about 0.9 alpha olefin to about 1 maleic anhydride] to [about
1.1 alpha olefin to about 2 maleic anhydride].
16. The method of claim 12, wherein the average molecular weight of
the alpha olefin copolymer ranges from about 2,000 to about
50,000.
17. The method of claim 12, wherein the phenol-formaldehyde resin
has a carbon chain selected from the group consisting of a carbon
chain of greater than 20 carbons, a carbon chain ranging from 6
carbons to 12 carbons, and combinations thereof.
18. The method of claim 12, wherein the oil-based fluid is selected
from the group consisting of a production fluid, a crude oil, a
shale oil, a black wax crude, a yellow wax crude, a synthetic
crude, an oil sand, and combinations thereof.
19. The method of claim 12, wherein the alpha olefin has a carbon
chain ranging from 18 carbons to 50 carbons.
20. The method of claim 12, wherein the at least one wax foulant is
present within the oil-based fluid in a total amount ranging from
about 0.1 wt % to about 50 wt %.
21. The method of claim 12, wherein the at least one wax foulant
has a carbon chain selected from the group consisting of a carbon
chain ranging from about 10 carbons to about 20 carbons, 20 carbons
to 30 carbons, greater than 30 carbons, and combinations
thereof.
22. A method of refining an oil-based fluid having at least one
paraffinic wax therein, the method comprising: adding an effective
amount of an additive to improve at least one property of the at
least one paraffinic wax foulant, where the additive is selected
from the group consisting of an alpha olefin copolymer, an alkyl
phenol-formaldehyde resin, an alkyl acrylate, a polyalkyl
methacrylate, ethylene vinyl acetate co-polymer, ethylene vinyl
acetate co-polymer terpolymer, imidazoline, and combinations
thereof; wherein the amount of the additive within the oil-based
fluid ranges from about 10 ppm to about 10000 ppm; and wherein the
at least one property is selected from the group consisting of the
amount of paraffinic wax foulant deposited, the amount of
paraffinic wax foulant dispersed, settling rate of the paraffinic
wax foulant, viscosity of the paraffinic wax foulant, shape of the
paraffinic wax foulant, and combinations thereof; and wherein the
temperature of the oil-based fluid ranges from about -40 C to about
100 C.
23. A treated wax composition, where the composition comprises: at
least one wax foulant; and an effective amount of an additive to an
improve at least one property of the at least one wax foulant,
where the additive is selected from the group consisting of an
alpha olefin copolymer, an alkyl phenol-formaldehyde resin, an
alkyl acrylate, a polyalkyl methacrylate, ethylene vinyl acetate
co-polymer, ethylene vinyl acetate terpolymer, imidazoline, and
combinations thereof; wherein the at least one property is selected
from the group consisting of the amount of wax foulant deposited,
the amount of wax foulant dispersed, settling rate of the wax
foulant, viscosity of the wax foulant, shape of the wax foulant,
and combinations thereof.
24. The treated wax composition of claim 23, further comprising an
oil-based fluid.
25. The treated wax composition of claim 24, wherein the oil-based
fluid is selected from the group consisting of a production fluid,
a crude oil, a shale oil, a black wax crude, a yellow wax crude, a
synthetic crude, an oil sand, and combinations thereof.
26. The treated wax composition of claim 24, wherein the at least
one wax foulant is present within the oil-based fluid in a total
amount ranging from about 0.1 wt % to about 50 wt %.
27. The treated wax composition of claim 23, wherein the effective
amount of the additive ranges from about 10 ppm to about 10,000
ppm.
28. The treated wax composition of claim 23, wherein the alpha
olefin copolymer is selected from the group consisting of alpha
olefin maleic anhydride copolymers, esters of alpha-olefin maleic
anhydride copolymers, imides of alpha-olefin maleic anhydride
copolymers, and combinations thereof.
29. The treated wax composition of claim 26, wherein the alpha
olefin copolymer has a ratio based on weight of alpha-olefin to
maleic anhydride ranging from [about 0.9 alpha olefin to about 1
maleic anhydride] to [about 1.1 alpha olefin to about 2 maleic
anhydride].
30. The treated wax composition of claim 23, wherein the average
molecular weight of the alpha olefin copolymer ranges from about
2,000 to about 50,000.
31. The treated wax composition of claim 23, wherein the
phenol-formaldehyde resin has a carbon chain selected from the
group consisting of a carbon chain of greater than 20 carbons, a
carbon chain ranging from 6 carbons to 12 carbons, and combinations
thereof.
32. The treated wax composition of claim 23, wherein the alpha
olefin has a carbon chain ranging from 18 carbons to 50
carbons.
33. The treated wax composition of claim 23, wherein the at least
one wax foulant has a carbon chain selected from the group
consisting of a carbon chain ranging from about 10 carbons to about
20 carbons, 20 carbons to 30 carbons, greater than 30 carbons, and
combinations thereof.
34. A treated wax composition comprising: at least one wax foulant;
an oil-based fluid; and an effective amount of an additive to
improve at least one property of the at least one wax foulant,
where the additive is selected from the group consisting of an
alpha olefin copolymer, an alkyl phenol-formaldehyde resin, an
alkyl acrylate, a polyalkyl methacrylate, ethylene vinyl acetate
co-polymer, ethylene vinyl acetate terpolymer, imidazoline, and
combinations thereof; wherein the at least one property is selected
from the group consisting of the amount of wax foulant deposited,
the amount of wax foulant dispersed, settling rate of the wax
foulant, viscosity of the wax foulant, shape of the wax foulant,
and combinations thereof.
Description
RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent
application Ser. No. 13/786,674, for "COLD FLOW IMPROVEMENT OF
DISTILLATE FUELS USING ALPHA-OLEFIN COMPOSITIONS", filed on Mar. 6,
2013, and claims the benefit of priority from the aforementioned
application, which is herein incorporated in its entirety.
TECHNICAL FIELD
[0002] The present invention relates to compositions and methods
for altering at least one property of at least one wax foulant
within an oil-based fluid, and more specifically relates to adding
an effective amount of an additive to the oil-based fluid where the
additive may be or include an alpha olefin copolymer, an alkyl
phenol-formaldehyde resin, an alkyl acrylate, a polyalkyl
methacrylate, ethylene vinyl acetate co-polymer, ethylene vinyl
acetate terpolymer, imidazoline, and combinations thereof.
BACKGROUND
[0003] Shale oil and other types of unconventional crude oils, such
as but not limited to black wax crude, yellow wax crude, and the
like, are being extracted because of the increasing difficulties to
extract and obtain conventional types of crude oils. Shale oil may
be produced from oil shale by pyrolysis, hydrogenation, thermal
dissolution, and the like to convert the organic matter within the
rock into synthetic oil and/or gas. The resulting shale oil may be
used immediately as a fuel or refined for the same purposes and
products as those derived from conventional crude oil.
[0004] Black wax crude and yellow wax crude are thick crude oils
with a higher paraffinic or wax content than conventional crude
oils found in North America. These waxy crudes are viscous and have
a high pour point, which means they become semi-solid at lower
temperatures. These waxy crudes may solidify quickly, so effective
transport and handling of these waxy crude oils has been
problematic. As a result, producers have started to look at
blending in shale oils to lower the pour point and reduce the
heating needed in the distribution system in order to deliver and
handle these type crudes.
[0005] These unconventional crude oils are increasingly available
in the U.S. and are relatively inexpensive to extract. Although
shale oils are typically light in nature with a relatively low pour
point (defined as the last temperature at which the oil had
fluidity) compared to many conventional crude oils, they tend to
have a higher concentration of paraffin and wax foulants. A
significant amount of long chain (e.g. greater than 30 carbons),
high molecular weight paraffin and wax compounds begin to
crystallize and precipitate out of the oil even at temperatures,
such as 100 F or above. While this crystallization can occur in
conventional oils, the delta between the onset of wax
crystallization, commonly referred to as wax appearance
temperature, and the pour point of these oils is generally greater
than conventional crude oils resulting in greater wax settling.
[0006] Due to this phenomena, refineries and terminals face
challenges as a result of wax settling out of the unconventional
crude oil when being transported by vessels (e.g. trucks, barges,
rail, etc.) used to deliver the oil. Such problems include, but are
not limited to, wax deposition and the potential plugging of
transfer lines leading from the point of oil delivery to tankage;
wax build up in the bottom of the storage tanks; wax build up in
the bottom of transport vessels; sludge formation comprised of
inorganics and asphaltenes destabilized by the paraffins; loss of
hydrocarbon recovery due to solidification in the bottom phase of
the oils as a result of paraffin buildup and sludge; the fouling in
preheat exchangers prior to the oil being distilled, and the like.
The unrecovered hydrocarbon and sludge in transport vessels
commonly referred to as "Remains On Board" or "ROB" results in
economic loss due to remediation/clean-up costs, increased
hazardous waste generation and the cost associated with disposal of
this waste, demurrage incurred on the vessels during clean up and
lost oil volumes.
[0007] Thus, there is an immediate and growing need for a chemical
solution. It would be desirable if additives were created for
improving the properties of paraffin or wax foulants within these
unconventional types of crude oils, conventional crude oil blends,
and the wax foulant that has already separated and deposited from
the oil-based fluid or ROB in the transport vessels, pipelines and
storage tanks; etc.
SUMMARY
[0008] There is provided, in one form, a treated fluid that may
include an oil-based fluid having at least one wax foulant therein.
The treated fluid also includes an effective amount of an additive
for improving at least one property of the wax foulant(s), such as
but not limited to wax foulant deposited, the amount of wax
dispersed, settling rate of the wax foulant, viscosity of the wax
foulant, shape of the wax foulant, and combinations thereof. The
additive may be or include an alpha olefin copolymer, an alkyl
phenol-formaldehyde resin, an alkyl acrylate, a polyalkyl
methacrylate, ethylene vinyl acetate co-polymer, ethylene vinyl
acetate terpolymer, imidazoline, and combinations thereof.
[0009] In another non-limiting embodiment, the wax foulant may be a
paraffinic wax, and the temperature of the treated fluid may range
from about -40 C to about 40 C. The oil-based fluid may be or
include a production fluid, a crude oil, a shale oil, a black wax
crude, a yellow wax crude, a synthetic crude, an oil sand, and
combinations thereof.
[0010] In a non-limiting embodiment, a method for altering at least
one property of at least one wax foulant within an oil-based fluid
is described. An effective amount of an additive may be added to an
oil-based fluid to improve properties of the wax foulant(s)
therein, such as but not limited to wax foulant deposited, the
amount of wax dispersed, settling rate of the wax foulant,
viscosity of the wax foulant, shape of the wax foulant, and
combinations thereof. The additive may be or include an alpha
olefin copolymer, an alkyl phenol-formaldehyde resin, an alkyl
acrylate, a polyalkyl methacrylate, ethylene vinyl acetate
co-polymer, ethylene vinyl acetate co-polymer terpolymer,
imidazoline, and combinations thereof.
[0011] In a non-limiting embodiment, the method may be or include
refining an oil-based fluid having at least one paraffinic wax
therein. An effective amount of an additive may be added to an
oil-based fluid to improve properties of the paraffinic wax
foulant(s) therein, such as but not limited to paraffinic wax
foulant deposited, the amount of paraffinic wax dispersed, settling
rate of the paraffinic wax foulant, viscosity of the paraffinic wax
foulant, shape of the paraffinic wax foulant, and combinations
thereof. The additive may be or include an alpha olefin copolymer,
an alkyl phenol-formaldehyde resin, an alkyl acrylate, a polyalkyl
methacrylate, ethylene vinyl acetate co-polymer, ethylene vinyl
acetate co-polymer terpolymer, imidazoline, and combinations
thereof. The amount of the additive within the oil-based fluid may
range from about 10 ppm to about 10000 ppm. The temperature of the
oil-based fluid may range from about -40 C to about 100 C.
[0012] In another embodiment, a solid wax composition derived from
an oil-based fluid is described. The solid wax composition may
include an effective amount of an additive to improve at least one
property of the at least one wax foulant, where the additive is
selected from the group consisting of an alpha olefin copolymer, an
alkyl phenol-formaldehyde resin, an alkyl acrylate, a polyalkyl
methacrylate, ethylene vinyl acetate co-polymer, ethylene vinyl
acetate terpolymer, imidazoline, and combinations thereof. The
improved properties may be or include improving the amount of wax
foulant deposited, the amount of wax foulant dispersed, settling
rate of the wax foulant, viscosity of the wax foulant, shape of the
wax foulant, and combinations thereof.
[0013] The additive added to the oil-based fluid or wax solid
appears to reduce the amount of the wax foulant that may be
deposited within the oil-based fluid and/or increase the amount of
wax foulant that may be dispersed within the oil-based fluid or wax
solid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 illustrates the viscosity curve of four different
samples of shale oil where each sample has a different additive
within it; and
[0015] FIG. 2 illustrates the viscosity curve of three different
samples of shale oil where each sample has a different additive
within it with a narrower temperature range than that of FIG.
1.
DETAILED DESCRIPTION
[0016] It has been discovered that an effective amount of an
additive may be added to an oil-based fluid or wax solid to improve
at least one property of at least one wax foulant therein. When the
additive is incorporated into the oil-based fluid or wax solid, the
amount of wax foulant deposited, the amount of wax dispersed,
settling rate of the wax foulant, viscosity of the wax foulant,
shape of the wax foulant, and combinations thereof. The additive
may be or include, but is not limited to an alpha olefin copolymer,
an alkyl phenol-formaldehyde resin, an alkyl acrylate, a polyalkyl
methacrylate, ethylene vinyl acetate (EVA) co-polymer, EVA
terpolymer, imidazoline, and combinations thereof.
[0017] Complete reduction in wax deposition or completely
increasing the dispersion of the wax foulants within the oil-based
fluid or wax solid is desirable, but it should be appreciated that
neither is necessary for the compositions and methods discussed
herein to be considered effective. Success is obtained if more wax
foulants are dispersed or less wax foulants are deposited using the
additive than in the absence of the additive. `Effective amount` is
defined herein to mean any amount of the additive that may improve
at least one property of the wax foulants within the oil-based
fluid or wax solid.
[0018] The specific type of components within the additive may vary
depending on the desired outcome, such as but not limited to
deposition control of the wax foulant or dispersion of the wax
foulant. For example, a C20-C24 alpha olefin maleic anhydride
copolymer may be reacted with an amine (hereinafter referred to as
a `long chain succinimide`). The long chain succinimide may also be
blended with an acrylate/vinyl pyrollidine copolymer in another
non-limiting embodiment.
[0019] While this long chain succinimide may improve properties of
both deposition control and dispersion of the wax foulant, it may
be better suited for improving dispersion. Dispersants function by
keeping the wax foulants from agglomerating together and slows the
settling of the wax foulants according to Stoke's Law. Dispersants
may also be beneficial in cleaning existing wax buildup, such as
solid wax buildup in the bottom of a barge or railroad car after
transportation of the oil-based fluid and in the bottom of tanks
used for storing the oil-based fluid prior to transporting or
processing.
[0020] Another non-limiting example involves a C20-24 and C30+
alpha olefin maleic anhydride copolymer that has been fully
esterified with a C18-C22 fatty alcohol (hereinafter referred to as
the `esterified long chain AO/MA copolymer`). Similarly, this
esterified long chain AO/MA copolymer may improve deposition
control and dispersion of the wax foulants, but it may be better
suited for reducing the amount of wax deposition. Additionally, the
esterified long chain AO/MA copolymer AO/MA may function as a wax
crystal modifier to impact the shape and characteristics of the
wax, such as but not limited to softening the wax.
[0021] A blend of the long chain succinimide and the esterified
long chain AO/MA copolymer may improve deposition control and
dispersion of the wax foulants, but the blend may be better suited
for reducing the amount of wax deposition. Worth noting is that the
blend has better results on wax deposition than either of its
components used alone.
[0022] The EVA copolymer and/or EVA terpolymer are more polar and
may function as wax crystal modifiers to impact the shape and
characteristics of the wax, such as but not limited to making the
wax softer or more malleable. The EVA copolymer and/or terpolymer
may attach to the wax crystal to modify its structure, or they may
provide a nucleation site for the wax crystal to keep the wax
crystal size smaller and less likely to precipitate from the
oil-based fluid. If the wax crystal does precipitate out, it is
less likely to settle when an EVA copolymer and/or terpolymer has
been added to the oil-based fluid. The EVA copolymers and/or
terpolymers may improve dispersion of the wax foulants more than
improving deposition control; however, both properties may be
improved by an additive having an EVA copolymer and/or terpolymer
component.
[0023] The exact amount of the additive may vary depending on the
temperature of the oil-based fluid, the amount of wax foulant(s)
therein, and the like. The temperature of the treated fluid may
range from about -40 C independently to about 100 C, alternatively
from about -10 C independently to about 65 C, alternatively from
about -10 C independently to about 40 C, or from about -10 C
independently to about 25 C. As used herein with respect to a
range, "independently" means that any lower threshold may be used
together with any upper threshold to give a suitable alternative
range.
[0024] Depending on the conditions of the oil-based fluid, the
amount of the additive within the treated fluid or added to the wax
solid may range from about 10 ppm independently to about 10,000
ppm, alternatively from about 200 ppm independently to about 5000
ppm, from about 200 ppm independently to about 1000 ppm in another
non-limiting embodiment, or from about 200 ppm independently to
about 600 ppm. Between about 10 ppm independently to 200 ppm, there
may be improved paraffin dispersion and wax deposition control, but
performance may not be ideal.
[0025] The alpha olefin copolymer may be or include, but is not
limited to, alpha olefin maleic anhydride copolymers, esters of
alpha-olefin maleic anhydride copolymers, imides of alpha-olefin
maleic anhydride copolymers, and combinations thereof.
Alternatively, the alpha olefin copolymer may be or include, but is
not limited to, alpha olefin maleic anhydride copolymers, esters of
alpha-olefin maleic anhydride copolymers, imides of alpha-olefin
maleic anhydride copolymers, and combinations thereof. The maleic
anhydride moiety may be intact, converted to a functional group,
such as but not limited to a half ester, a full ester, a di-acid,
an acid/ester, an imide; and combinations thereof.
[0026] The alpha olefin copolymer may have a ratio based on weight
of alpha-olefin to maleic anhydride ranging from [about 0.9 alpha
olefin to about 1 maleic anhydride] to [about 1.1 alpha olefin to
about 2 maleic anhydride], such as a 1 to 2 ratio of alpha-olefin
to maleic anhydride, a 1.2 to 1 ratio of alpha-olefin to maleic
anhydride, a 0.9 to 1 ratio of alpha-olefin to maleic anhydride, a
1.1 to 1 ratio of alpha-olefin to maleic anhydride, and the like.
The average molecular weight of the alpha olefin copolymer may
range from about 2,000 independently to about 50,000, or from about
20,000 independently to about 30,000 in a non-limiting
embodiment.
[0027] The alpha olefin may have a carbon chain length ranging from
about 18 carbons independently to about 50 carbons, alternatively
from about 20 carbons independently to about 24 carbons, from about
26 carbons independently to about 28 carbons, or from about 30
carbons independently to about 50 carbons. The phenol-formaldehyde
resin may have a carbon chain length, such as but not limited to a
carbon chain greater than 20 carbons, a carbon chain ranging from 6
carbons to 12 carbons, and combinations thereof.
[0028] Non-limiting examples of an alkyl acrylate may be or
include, but are not limited to C16-C22 methacrylates, C16-C22
acrylates, and combinations thereof. Non-limiting examples of a
polyalkyl methacrylate may be or include, but are not limited to
C16-C22 methacrylates co-polymerized with C16-C22 acrylates, for
example stearyl methacrylate/behenyl acrylate co-polymer at a ratio
of 1:1 or 1:2, and combinations thereof. Non-limiting examples of
an ethylene vinyl acetate co-polymer may be or include, but are not
limited to ethylene copolymerized with between 18-45% vinyl
acetate, and combinations thereof. Non-limiting examples of an
ethylene vinyl acetate terpolymer may be or include, but are not
limited to ethylene vinyl acetate copolymer reacted with a
co-monomer such as maleic anhydride, isobutylene or alpha-olefins
between C6-C28, and combinations thereof. Non-limiting examples of
an imidazoline may be or include, but are not limited to monomer or
dimer fatty acids between C10-C36 reacted with amines, polyamines
or alkanolamines, alicyclic carboxylic acids reacted with amines,
polyamines or alkanolamines, and combinations thereof.
[0029] The oil-based fluid may be or include, but is not limited
to, a production fluid, a crude oil, a shale oil, a black wax
crude, a yellow wax crude, a synthetic crude, an oil sand, and
combinations thereof. The amount of the wax foulant within the
oil-based fluid may range from about 0.1 wt % to about 50% wt %,
alternatively from about 0.1 wt % independently to about 30 wt %,
alternatively from about 10 wt % independently to about 25 wt % in
another non-limiting embodiment. The wax foulant(s) may have a
carbon chain, such as but not limited to, a carbon chain ranging
from about 10 carbons independently to about 20 carbons, greater
than 20 carbons, and combinations thereof. In a non-limiting
embodiment, the wax foulant may be a paraffin wax. "Paraffin wax"
is defined herein to be a wax having a carbon chain length ranging
from 18 carbons to 40 carbons.
[0030] Any suitable mixing apparatus may be used to incorporate the
additive into the oil-based fluid. In the case of batch mixing, the
additive and the oil-based fluid are blended for a period of time
sufficient for incorporating the additive into the oil-based fluid.
In an alternative embodiment, the additive may be added to the
oil-based fluid as an injection, e.g. for a production fluid. In
another non-limiting embodiment, the additive may be applied to the
surface or within the matrix of deposited wax foulant, e.g. to the
surface of deposited wax in railroad car. This may reduce the
amount of wax foulant already deposited and/or increase the amount
of dispersed wax foulant. The method may include, but is not
limited to, direct spray of the additive on the solid surface of
the wax foulant, injection within the solid wax foulant or another
means for direct contact to the wax foulant by the additive.
[0031] Worth noting here, the additive may be added to the
oil-based fluid having wax foulant(s) therein when the oil-based
fluid and/or the wax foulants are in a fluid state, or the additive
may be added directly to a solidified wax mass. The solidified waxy
mass may or may not have an oil-based fluid therein; typically, the
wax and oil-based fluid remnants solidify, and a solid waxy
composition remains deposited. In another non-limiting embodiment,
the additive may be added directly to the deposited wax foulants
where the wax foulants have no oil-based fluid within the
solidified wax, such as but not limited to deposited wax foulants
in either the bulk oil holding system or within the processing unit
for the oil-based fluid, a railroad car bottom, etc.
[0032] The amount of the additive may be added to the oil-based
fluid in phases. For example, a single phase of an additive may be
added to the oil-based fluid in amount of 400 ppm. Alternatively,
additive may be added to the oil-based fluid in multiple phases,
e.g. where 400 ppm is added to the oil-based fluid in three phases
to total 1200 ppm over a designated time interval. As used in this
example, 400 ppm is not limiting to the amount of additive that may
be added to the oil-based fluid if a multi-phasic addition of the
additive is desirable; the amount of additive that may be added
when using a multi-phasic falls within the range of additive
amounts previously described. Said differently, it may be desirable
to one skilled in the art to add the additive in two phases where
the first phase addition is 10000 ppm, and the second phase
addition is 5000 ppm.
[0033] The invention will be further described with respect to the
following Examples, which are not meant to limit the invention, but
rather to further illustrate the various embodiments.
EXAMPLE 1
[0034] FIG. 1 illustrates the viscosity curve of four different
samples of shale oil where each sample has a different additive
within it. The blank has no additive. Additive A is a straight
alpha olefin maleic anhydride copolymer (C20-C24 and C30+)
esterified with a long chain (C18-C22) fatty alcohol. Additive A is
present within the oil-based fluid in an amount of 200 ppm based on
volume. Additive B is a C20-C24 alpha olefin maleic anhydride
copolymer reacted with an amine (a long chain succinimide).
Additive B is present within the oil-based fluid in an amount of
200 ppm based on volume. Additive C is a C20-C24 and C30+ alpha
olefin maleic anhydride copolymer that has been fully esterified
with a C18-C22 fatty alcohol blended 1:1 with a C20-C24 alpha
olefin maleic anhydride copolymer reacted with an amine (a long
chain succinimide). Additive C is present within the oil-based
fluid in an amount of 200 ppm based on volume. As noted by the
graph, additives A-C have an improved viscosity from -10 C to 65 C
compared to the blank.
EXAMPLE 2
[0035] FIG. 2 illustrates the viscosity curve of three different
samples of shale oil where each sample has a different additive
within it. The blank has no additive. Additive A and Additive C are
the same as those noted in FIG. 1. Additive A is present within the
oil-based fluid in an amount of 200 ppm based on volume. Additive C
is present within the oil-based fluid in an amount of 200 ppm based
on volume. As noted by the graph, additives A and C have an
improved viscosity from -10 C to 25 C compared to the blank.
EXAMPLE 3
[0036] TABLE 1 compares the amount of deposited wax, the deposited
density, the weight percent inhibition, and the bare probe testing
for the various types of additives within a Utica shale oil-based
fluid. Additives A-C are the same as additives described in FIGS. 1
and 2. Additive D is a C24-C28 alpha olefin maleic anhydride
copolymer with no esterification or imidization. Additive E is a
2:1 blend of additive A and D. All of the additives were effective
for improving the deposited weight, the deposited density, the
weight percent inhibition, and the bare probe testing. However, the
Additive C was the most effective additive for improving the
deposited weight, the deposited density, the weight percent
inhibition, and the bare probe testing. Moreover, increasing the
dosage of the Additive C from 200 ppm to 400 ppm increased the
improvement for the deposited weight, the deposited density, and
the weight percent inhibition.
[0037] The cold finger test results of TABLE 1 were done at a
condition temperature of 150.degree. F., a treatment temperature of
150.degree. F., a bulk oil temperature of 95.degree. F., a probe
temperature of 70.degree. F., a stir speed of 450 rpm, and a
duration of 24 hours.
TABLE-US-00001 TABLE 1 Additive Effect on Wax Deposition COLD
FINGER TEST RESULTS Deposit Dosage Deposit wt. density Wt. % Bare
Chemical (ppm) (gm) (gm/m{circumflex over ( )}2) inhibition probe
(%) Blank n/a 0.5166 90.07 n/a 0 A 200 0.133 22.84 74.65 20 D 200
0.2417 40.5 55.04 10 B 200 0.4297 78.64 12.69 5 E 200 0.2296 40.64
54.88 50 C 200 0.0782 13.19 85.36 90 C 400 0.0485 8.52 90.54 95
EXAMPLE 4
[0038] TABLE 2 compares additive A with additive C on deposited
wax, the deposited density, and the weight percent inhibition
within a Utica shale oil-based fluid. As noted by TABLE 2, additive
C was more effective at improving the deposited weight, the
deposited density, and the weight percent inhibition. Moreover,
increasing the dosage of additive C from 300 ppm to 600 ppm
increased the improvement for the deposited weight, the deposited
density, and the weight percent inhibition.
[0039] The cold finger test results of TABLE 2 were done at a
condition temperature of 150.degree. F., a treatment temperature of
150.degree. F., a bulk oil temperature of 103.degree. F., a probe
temperature of 73.degree. F., and a stir speed of 750 rpm.
TABLE-US-00002 TABLE 2 Additive Effect on Paraffin Deposition COLD
FINGER TEST RESULTS Dosage Deposit wt. Deposit Wt. % Chemical (ppm)
(gm) density (gm/m{circumflex over ( )}2) inhibition Blank n/a
0.5143 87.76 0 A 300 0.2759 49.13 44 A 600 0.0893 15.8 82 C 300
0.0784 13.92 84.1 C 600 0.0562 9.47 89.2
[0040] In the foregoing specification, the invention has been
described with reference to specific embodiments thereof, and has
been described as effective in providing fluids and methods for
altering at least one property of at least one wax foulant within
an oil-based fluid. However, it will be evident that various
modifications and changes can be made thereto without departing
from the broader spirit or scope of the invention as set forth in
the appended claims. Accordingly, the specification is to be
regarded in an illustrative rather than a restrictive sense. For
example, specific oil-based fluids, additives, alpha olefin
copolymers, wax foulants, and modifications falling within the
claimed parameters, but not specifically identified or tried in a
particular fluid, or method, are expected to be within the scope of
this invention.
[0041] The present invention may suitably comprise, consist or
consist essentially of the elements disclosed and may be practiced
in the absence of an element not disclosed. For instance, the
treated fluid may consist of or consist essentially of an oil-based
fluid comprising at least one wax foulant, and an effective amount
of an additive to an improve at least one property of the wax
foulant, where the additive is selected from the group consisting
of an alpha olefin copolymer, an alkyl phenol-formaldehyde resin,
an alkyl acrylate, a polyalkyl methacrylate, ethylene vinyl acetate
co-polymer, ethylene vinyl acetate terpolymer, imidazoline, and
combinations thereof; where the property is selected from the group
consisting of the amount of wax foulant deposited, the amount of
wax foulant dispersed, settling rate of the wax foulant, viscosity
of the wax foulant, shape of the wax foulant, and combinations
thereof.
[0042] There is further provided a method for improving at least
one property of at least one wax foulant within an oil-based fluid
where the method consists of or consists essentially of adding an
effective amount of an additive to improve at least one property of
the wax foulant where the additive is selected from the group
consisting of an alpha olefin copolymer, an alkyl
phenol-formaldehyde resin, an alkyl acrylate, a polyalkyl
methacrylate, ethylene vinyl acetate co-polymer, ethylene vinyl
acetate terpolymer, imidazoline, and combinations thereof; and
where at least one property is selected from the group consisting
of the amount of wax foulant deposited, the amount of wax foulant
dispersed, settling rate of the wax foulant, viscosity of the wax
foulant, shape of the wax foulant, and combinations thereof.
[0043] The words "comprising" and "comprises" as used throughout
the claims, are to be interpreted to mean "including but not
limited to" and "includes but not limited to", respectively.
* * * * *