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Sommaire du brevet 2765788 

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Disponibilité de l'Abrégé et des Revendications

L'apparition de différences dans le texte et l'image des Revendications et de l'Abrégé dépend du moment auquel le document est publié. Les textes des Revendications et de l'Abrégé sont affichés :

  • lorsque la demande peut être examinée par le public;
  • lorsque le brevet est émis (délivrance).
(12) Demande de brevet: (11) CA 2765788
(54) Titre français: EMULSIONS STABILISEES PAR DES PARTICULES POUR EXTRACTION D'HYDROCARBURES A PARTIR DE SABLES BITUMINEUX ET DE SCHISTE BITUMINEUX
(54) Titre anglais: PARTICLE STABILIZED EMULSIONS FOR EXTRACTION OF HYDROCARBONS FROM OIL SANDS AND OIL SHALE
Statut: Réputée abandonnée et au-delà du délai pour le rétablissement - en attente de la réponse à l’avis de communication rejetée
Données bibliographiques
(51) Classification internationale des brevets (CIB):
  • E21B 43/22 (2006.01)
  • C9K 8/58 (2006.01)
(72) Inventeurs :
  • RYAN, DAVID K. (Etats-Unis d'Amérique)
  • GOLOMB, DAN S. (Etats-Unis d'Amérique)
  • BARRY, EUGENE F. (Etats-Unis d'Amérique)
  • WOODS, MICHAEL J. (Etats-Unis d'Amérique)
  • SWETT, PETER A. (Etats-Unis d'Amérique)
(73) Titulaires :
  • UNIVERSITY OF MASSACHUSETTS
(71) Demandeurs :
  • UNIVERSITY OF MASSACHUSETTS (Etats-Unis d'Amérique)
(74) Agent: BORDEN LADNER GERVAIS LLP
(74) Co-agent:
(45) Délivré:
(86) Date de dépôt PCT: 2010-06-17
(87) Mise à la disponibilité du public: 2010-12-23
Licence disponible: S.O.
Cédé au domaine public: S.O.
(25) Langue des documents déposés: Anglais

Traité de coopération en matière de brevets (PCT): Oui
(86) Numéro de la demande PCT: PCT/US2010/038998
(87) Numéro de publication internationale PCT: US2010038998
(85) Entrée nationale: 2011-12-15

(30) Données de priorité de la demande:
Numéro de la demande Pays / territoire Date
61/268,875 (Etats-Unis d'Amérique) 2009-06-17

Abrégés

Abrégé français

L'invention porte sur des émulsions stabilisées par des particules, de la sorte qui peut utiliser du dioxyde de carbone liquide et/ou du dioxyde de carbone supercritique en tant que phase continue ou phase dispersée, pour l'extraction d'hydrocarbures.


Abrégé anglais

Particle-stabilized emulsions, of the sort which can utilize liquid carbon dioxide and/or supercritical carbon dioxide as a continuous or a dispersed phase, for hydrocarbon extraction.

Revendications

Note : Les revendications sont présentées dans la langue officielle dans laquelle elles ont été soumises.


What is claimed.
1. A primary method of subterranean hydrocarbon recovery, said method
comprising:
providing a subterranean formation comprising a hydrocarbon component, said
component selected from a tar, a bitumen precursor of said tar, an oil and a
kerogen
precursor of said oil;
contacting said subterranean formation with a fluid medium comprising an
emulsion comprising an aqueous component dispersed in a continuous phase at
least
partially immiscible with said aqueous component and a particulate component
selected from hydrophobic components and combinations thereof, and hydrophilic
components and combinations thereof, said particulate component in an amount
sufficient for at least partial emulsification, said contact for at least one
of a time and
at a pressure at least partially sufficient to displace said hydrocarbon
component from
said formation; and
recovering said hydrocarbon component.
2. The method of claim 1 wherein said fluid medium comprises a component
selected from a liquid carbon dioxide component, a supercritical carbon
dioxide
component and combinations thereof.
3. The method of claim 2 wherein a said carbon dioxide component comprises
greater than about 1 weight percent of said emulsion.
4. The method of claim 1 wherein said fluid medium comprises a component
selected from about C1 to about C20 hydrocarbons, about C2 to about C40 ethers
and
combinations thereof.
5. The method of claim 1 wherein said hydrophobic particulate component is
selected from coal particles, carbon black particles, activated carbon
particles,
asphaltene particles, petrocoke particles, fluorocarbon particles, and
combinations of
said components.
6. The method of claim 1 wherein said hydrophilic particulate component is
selected from pulverized limestone particles, pulverized sand particles,
pulverized
hydrophilic mineral particles, pulverized hydrophilic rock particles,
pulverized clay
particles and combinations of said components.
38

7. The method of claim 1 wherein said particulate components are dimensioned
from about 5 nanometers to about 100 µm.
8. The method of claim 1 wherein said fluid medium contact is selected from
in situ contact and ex situ contact with respect to said formation.
9. The method of claim 8 wherein said contact is in situ, said method
comprising
contacting said formation with an organic component at least partially
immiscible
with said aqueous component, said organic component comprising a compound
selected from C2 to about C20 hydrocarbon compounds, said hydrocarbon
compounds
selected from straight-chain, branched and cyclic aliphatic compounds and
aromatic
compounds, and C2 to about C40 ether compounds, and combinations of said
hydrocarbon and ether compounds, said contact prior to said ex situ contact.
10. The method of claim 8 wherein said contact is ex situ, said method
comprising
contacting excavated formation with an organic component at least partially
immiscible with said aqueous component, said organic component comprising a
compound selected from C2 to about C20 hydrocarbon compounds, said hydrocarbon
compounds selected from straight-chain, branched and cyclic aliphatic
compounds
and aromatic compounds, and C2 to about C40 ether compounds, and combinations
of
said hydrocarbon and ether compounds, said contact prior to said ex situ
contact.
11. A method of using a particulate-stabilized carbon dioxide emulsion for
hydrocarbon extraction from an oil sand/oil shale formation, said method
comprising:
providing a formation comprising at least one of oil sand and oil shale, and a
hydrocarbon component deposited therewith;
contacting said formation with an emulsion comprising a liquid carbon dioxide
component, a supercritical carbon dioxide component or a combination thereof,
and
an aqueous component, said emulsion comprising a particulate component
selected
from hydrophobic components and combinations thereof, said particulate
component
in an amount sufficient for at least partial emulsification, said contact for
at least one
of a time and at a pressure at least partially sufficient to displace said
hydrocarbon
from said formation; and
recovering said hydrocarbon component, and at least one of a portion of said
emulsion and a carbon dioxide component thereof.
39

12. The method of claim 11 wherein said continuous phase of said emulsion
comprises a said carbon dioxide component comprising greater than about 1
weight
percent of said emulsion.
13. The method of claim 11 wherein said hydrophobic particulate component is
selected from coal particles, carbon black particles, activated carbon
particles,
asphaltene particles, petrocoke particles, fluorocarbon particles and
combinations of
said components.
14. The method of claim 11 wherein said emulsion contact is ex situ.
15. A method of using a particulate-stabilized aqueous liquid-carbon dioxide
emulsion for hydrocarbon extraction from an oil sand/oil shale formation, said
method
comprising:
providing a formation comprising at least one of oil sand and oil shale, and a
hydrocarbon component deposited therewith;
contacting said formation with an emulsion comprising a liquid carbon dioxide
component, a supercritical carbon dioxide component or a combination thereof,
and
an aqueous component, said emulsion comprising a particle component selected
from
hydrophilic particulate components and combinations thereof, said particulate
component in an amount sufficient for at least partial emulsification, said
contact for
at least one of a time and at a pressure at least partially sufficient to
displace said
hydrocarbon from said formation; and
recovering said hydrocarbon component, and at least one of a portion of said
emulsion and a carbon dioxide component thereof.
16. The method of claim 15 wherein said continuous phase of said emulsion
comprises a said aqueous component comprising greater than about 1 weight
percent
of said emulsion.
17. The method of claim 15 wherein said hydrophilic particulate component is
selected from pulverized limestone particles, pulverized sand particles,
pulverized
hydrophilic mineral particles, pulverized rock particles, pulverized clay
particles, and
combinations of said components.
18. The method of claim 15 wherein said emulsion contact is ex situ.

Description

Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.


CA 02765788 2011-12-15
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Particle Stabilized Emulsions for Extraction of
Hydrocarbons from Oil Sands and Oil Shale
[0001 ] This application claims priority benefit from Application Serial No.
61/268,875, filed June 17, 2009, the entirety of which is incorporated herein
by
reference.
Background of the Invention
[0002] Oil sands, also known as tar sands, and oil shales are large deposits
of
energy rich bitumen or kerogen found immobilized in sand or rock strata at
numerous
locations around the world. The most notable oil sand reserves are located in
Alberta,
Canada, and Venezuela. The largest oil shale deposits are in North America,
but the
Middle East, Australia and Europe (e.g. Estonia) all have significant
deposits.
Bitumen and kerogen are high carbon content materials produced as a result of
fossilization of primeval fauna and flora. In order to use such hydrocarbons
as energy
sources and feed stocks for oil refineries, initial extraction from the
mineral matter
(sand and shale) is necessary.
[0003] Current methods of hydrocarbon extraction from oil sands and oil shales
use mainly ex situ methods in which the sand or shale deposits are excavated
and
processed in overland facilities by thermal or chemical treatment processes.
Such
methods are typically quite energy intensive, reducing overall net gain.
Furthermore,
large quantities of water are consumed, invariably in areas where water
resources are
limited. As another consideration, extraction agents are typically specialty
chemicals,
some of them toxic to human health and the environment. Altogether, the
removal of
the "overburden" covering the oil sand or oil shale deposits causes deep scars
to the
pristine environment where such deposits are located. Furthermore, the
disposal of
the residue after the extraction process causes deleterious environmental
problems,
considering that the residue still contains significant amounts of the
original bitumen
(tar) and kerogen in the excavated mineral matter, plus the addition of
potential toxic
chemical agents. To illustrate the residue disposal problem, oil sands and oil
shales
contain only up to 15% of bitumen or kerogen, thus, 85% or more of the
excavated

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treated sand or shale needs to be safely disposed of. Therefore, ex situ
extraction
methods, in addition to being energy and cost intensive, elicit considerable
public and
political opposition.
[0004] Accordingly, there remains an on-going search in the art for a method
to
enhance recovery/extraction of oil sand and oil shale deposits, to better
utilize the
benefits and advantages associated with such available hydrocarbon resources.
Summary of the Invention
[0005] In light of the foregoing, it is an object of the present invention to
provide one or more methods and/or systems for hydrocarbon recovery from oil
sand
and oil shale deposits, thereby overcoming various deficiencies and
shortcomings of
the prior art, including those outlined above. It will be understood by those
skilled in
the art that one or more aspects of this invention can meet certain
objectives, while
one or more other aspects can meet certain other objectives. Each objective
may not
apply equally, in all its respects, to every aspect of this invention. As
such, the
following objects can be viewed in the alternative with respect to any one
aspect of
this invention.
[0006] It can be an object of this invention to provide a method for
hydrocarbon
recovery from oil sand and oil shale deposits, with less environmental impact
as
compared to processes of the prior art.
[0007] It can be another object of the present invention, alone or in
conjunction
with one or more objectives, to provide an approach to hydrocarbon recovery
exhibiting greater efficiencies and cost benefits, as compared to the prior
art.
[0008] Other objects, features, benefits and advantages of the present
invention
will be apparent from this summary and the following descriptions of certain
embodiments, and will be readily apparent to those skilled in the art having
knowledge of various hydrocarbon recovery processes and production techniques.
Such objects, features, benefits and advantages will be apparent from the
above as
taken into conjunction with the accompanying examples, data, figures and all
reasonable inferences to be drawn therefrom.
2

CA 02765788 2011-12-15
WO 2010/148204
[0009] In part, the present invention can be directed to a primary method of
subterranean hydrocarbon recovery. Such a method can comprise providing a
subterranean formation comprising a hydrocarbon component, such a component as
can be selected from a tar, an oil and/or bitumen and kerogen precursors
thereof;
contacting the material content of such a subterranean formation with a fluid
medium
comprising an emulsion comprising a liquid carbon dioxide and/or supercritical
carbon dioxide component, an aqueous component and a particulate component
selected from hydrophilic components and/or combinations thereof and
hydrophobic
components and/or combinations thereof, such particulate component(s) in an
amount
sufficient for at least partial emulsification, such contact for a time and/or
at a pressure
at least partially sufficient to displace the hydrocarbon component from the
formation;
and recovering the hydrocarbon component and, optionally, at least a portion
of the
fluid medium and/or emulsion.
[0010] In certain embodiments, the fluid medium can comprise an emulsion
comprising a dispersed phase comprising an aqueous component, a continuous
phase
comprising one or more such carbon dioxide components and one or more
hydrophobic particulate components, such hydrophobic particles can include but
are
not limited to those described elsewhere herein or as would be otherwise known
to
those skilled in the art made aware of this invention.
[0011 ] In certain other embodiments, the fluid medium can comprise an
emulsion comprising a dispersed phase comprising one or more such carbon
dioxide
components, a continuous phase comprising an aqueous component and one or more
hydrophilic particulate components. Such hydrophilic particulate components
can
include but are not limited to those described elsewhere herein or as would
otherwise
be known skilled in the art skilled made aware of this invention.
[0012] In certain embodiments, the subterranean formation can comprise but is
not limited to a oil sand and/or oil shale deposit. In such embodiments, a
hydrocarbon
component can be selected from a tar and an oil and bitumen and/or kerogen
precursors thererof. Regardless, in certain such embodiments, the material
content of
such a formation can be excavated and contact with a fluid medium of the sort
discussed above can be ex situ and/or above ground with regard to the
subterranean
3

CA 02765788 2011-12-15
WO 2010/148204 r~ ii~~wiviv,o o
formation. In certain other embodiments, the material content can be contacted
in situ
and/or under ground with respect to the subterranean formation. Whether such
contact
is ex- or in-situ, such a fluid medium can comprise an emulsion comprising a
liquid
carbon dioxide and/or supercritical carbon dioxide component, an aqueous
component
and a particulate component selected from hydrophilic components and/or
combination thereof and hydrophobic components and/or combinations thereof.
[0013] In certain such non-limiting embodiments, such a fluid medium can
comprise an emulsion comprising a dispersed phase comprising an aqueous
component, a continuous phase comprising one or more such carbon dioxide
components and one or more hydrophobic particulate components. In certain
other
embodiments, such a fluid medium can comprise an emulsion comprising a
dispersed
phase comprising one or more such carbon dioxide components, a continuous
phase
comprising an aqueous component and one or more hydrophilic particulate
components.
[0014] Without regard to any particular hydrocarbon or subterranean formation,
in certain non-limiting embodiments, a carbon dioxide component of an emulsion
used in conjunction with this invention, whether part of a continuous phase or
dispersed phase, can be present in an amount greater than about 1 wt. % of the
emulsion.
[0015] Regardless, particles utilized in conjunction with such an emulsion can
be dimensioned from about 5 nanometers or less to about 100 m or more. With
correlation to a dispersed phase of such an emulsion, particulate dimension
can be
about 5x to about 50x smaller than a dimensional aspect of any such dispersed
phase.
These and various other non-limiting emulsion parameters are discussed
elsewhere
herein or as would be understood by those skilled in the art made aware of
this
invention. Such parameters can be varied, limited only by the physical
properties
and/or functional effect desired of a particular emulsion, in the context of a
particular
subterranean formation and/or hydrocarbon recovery.
[0016] Regardless of whether such fluid medium contact is in situ or ex situ,
such a method can comprise contact of said formation with an organic component
at
least partially immiscible with an aqueous component of such a fluid medium.
In
4

CA 02765788 2011-12-15
WO 2010/148204 r%_ /uawivivao o
certain embodiments, without limitation, such an organic compound can be
selected
from C2 to about C20 hydrocarbon compounds, C2 to about C40 ether compounds
and
combinations of such hydrocarbon and/or ether compounds, such compounds of the
sort illustrated below or as would otherwise be understood by those skilled in
the art
made aware of this invention. Regardless, such contact can be prior to either
such in
situ or ex situ contact and can be considered as an optional pre-treatment
aspect or
component of the present methodologies.
[0017] In part, the present invention can also be directed to a method of
using a
particulate-stabilized emulsion for hydrocarbon extraction from oil sand/oil
shale.
Such a method can comprise providing a oil sand, oil shale or a related
formation
comprising a hydrocarbon; contacting the material content of such a formation,
whether in situ or ex situ, with a fluid medium comprising an emulsion
comprising an
aqueous component, a component at least partially immiscible with such an
aqueous
component and a particulate component selected from hydrophilic components
and/or
combinations thereof and hydrophobic components and/or combinations thereof,
such
a particulate component(s) in an amount sufficient for at least partial
emulsification,
such contact for a time and/or at a pressure at least partially sufficient to
displace the
hydrocarbon deposit from the formation; and recovering the hydrocarbon
component
and at least a portion of the emulsion.
[0018] In certain embodiments, a hydrocarbon component can be selected from
a tar, an oil, a bitumen, a kerogen and/or combinations thereof. Regardless,
such a
fluid medium can comprise an emulsion comprising a dispersed phase comprising
an
aqueous component, a continuous phase comprising one or more components at
least
partially immiscible with such an aqueous component and one or more
hydrophobic
particulate components. As illustrated elsewhere herein, such a continuous
phase can
comprise a liquid carbon dioxide component, a supercritical carbon dioxide
component, an organic component at least partially immiscible with an aqueous
component and/or combinations thereof. With regard to such an organic
component,
whether alone or in combination with a carbon dioxide component, such an
organic
component can, without limitation, be selected from about C2 to about C,0
hydrocarbons, from about C2 to about C40 ethers and from combinations thereof.

CA 02765788 2011-12-15
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Regardless, such a dispersed phase can comprise water, water-miscible
components
and combinations thereof. Such hydrophobic particulate components can be
selected
from those described elsewhere herein or as would otherwise be understood by
those
skilled in the art made aware of this invention.
[0019] Likewise, without regard to hydrocarbon component, such a fluid
medium can comprise an emulsion comprising a continuous phase comprising an
aqueous component, a dispersed phase comprising one or more components at
least
partially immiscible with such an aqueous component and one or more
hydrophilic
particulate components. As illustrated elsewhere herein, such a continuous
phase can
comprise an aqueous component comprising water, water-miscible components and
combinations thereof. Such water-miscible components can, without limitation,
be
selected from CI to about C6 alcohols, CI to about C6 ketones, C2 to about C6
glycols,
such components as can comprise one or more ionic and/or non-ionic components
and/or solutes therein. Regardless, such a dispersed phase can comprise a
liquid
carbon dioxide component, a supercritical carbon dioxide component, an organic
component at least partially immiscible with such an aqueous component and
combinations thereof. Such hydrophilic particulate components can be selected
from
those described elsewhere herein or as would otherwise be understood by those
skilled
in the art made aware of this invention.
[0020] Without regard to any particular dispersed or continuous phase,
hydrophobic particulate components can include but are not limited to coal
particles,
carbon black particles, petrocoke particles, Teflon particles, latex
particles, polymer
bead particles, protein particles, modified cellulose particles, chitosan
particles, clay
particles, and various other hydrophobic particles known to those skilled in
the art,
whether naturally-available or prepared by grinding, pulverizing,
crystallizing,
chemical synthesis, chemical coating and/or surface modification, pyrolysis or
petroleum refining. Likewise, hydrophilic particulate components can include,
but are
not limited to carbonate mineral particles, silicate mineral particles, clay
mineral
particles, latex particles, polymer bead particles, protein particles,
cellulosic particles,
modified cellulose particles, chitin particles, chitosan particles, iron
particles, iron
oxide particles, cadmium selenide particles and various other hydrophilic
particles
6

CA 02765788 2011-12-15
WU 2010/148204 PCT/US2010/038998
known to those skilled in the art, whether prepared by grinding, pulverizing,
crystallizing, chemical coating and/or surface modification or chemical
synthesis.
[0021] Whether such a method is effected in situ or ex situ with respect to a
particular formation, in certain non-limiting embodiments, such an emulsion
can
comprise one or more carbon dioxide components. In certain such embodiments, a
carbon dioxide component, whether part of a continuous phase or dispersed
phase, can
be present in an amount greater than about 1 wt. % of the emulsion.
Regardless,
particulates utilized in conjunction with such an emulsion--whether
hydrophobic or
hydrophilic--can be dimensioned from about 5 nanometers or less to about 100
m or
more. Without limitation, nanometer-dimensioned particulates, i.e.,
nanoparticles, can
be used effectively in the context of in situ contact with an oil sand/oil
shale
formation. With correlation to a dispersed phase of such an emulsion,
particulate
dimension can be about 5 x to about 50 x smaller than a dimensional aspect of
any
such dispersed phase. These and various other non-limiting emulsion parameters
are
discussed elsewhere herein or as would be understood by those skilled in the
art made
aware of this invention. Such parameters can be varied, limited only by the
physical
properties and/or functional effect desired of a particular emulsion, in the
context of a
particular subterranean formation and/or hydrocarbon recovery.
[0022] With respect to either the methods and emulsions of the present
invention, the steps and components thereof can suitably comprise, consist of,
or
consist essentially of any of the steps or components disclosed herein. Each
such
method or step and emulsion or component thereof is distinguishable,
characteristically or functionally contrasted and can be practiced in
conjunction with
the present invention separate and apart from another. Accordingly, it should
also be
understood that inventive methods and/or emulsions, as illustratively
disclosed herein,
can be practiced or utilized in the absence of any one component or step which
may or
may not be disclosed, referenced or inferred herein, the absence of which may
or may
not be specifically disclosed, referenced or inferred herein.
7

CA 02765788 2011-12-15
VV %-# .U1Uf145hU4 PCT/US2010/038998
Brief Description of the Drawings
[0023]Non-limiting embodiments of the present invention can be described by
way of example with reference to the accompanying figures, which are schematic
and
are not intended to be drawn to scale. In the figures, each identical or
nearly identical
component illustrated is typically represented by a single numeral. For
purposes of
clarity, not every component is labeled in every figure, nor is every
component of
each embodiment of the invention shown where illustration is not necessary to
allow
those of ordinary skill in the art to understand the invention. In the
figures:
[0024] FIG. 1 shows a schematic diagram of a particle stabilized emulsion
according to one embodiment of the invention;
[0025] FIG. 2 shows droplets of water in a dodecane continuous phase
stabilized by carbon black particles according to another embodiment of the
invention;
[0026] FIG. 3 shows a schematic diagram of a high-pressure batch reactor for
forming an emulsion according to another embodiment of the invention;
[0027] FIG. 4 shows a static mixer that can be used to form an emulsion
according to another embodiment of the invention;
[0028] FIG. 5 shows a static mixer emulsion apparatus according to another
embodiment of the invention;
[0029] FIG. 6 shows a system for recovering hydrocarbon from a subterranean
formation according to another embodiment of the invention;
[0030] FIG. 7 shows one particular system for extracting hydrocarbon(s) from
excavated oil sand/oil shale, according to another embodiment of the
invention; and
[0031 ]FIGS. 8A-8B illustrate oil extraction from sand, in accordance with one
embodiment of this invention.
8

CA 02765788 2011-12-15
WO 20101148204 PCT/US2010/038998
Detailed Description of Certain Embodiments.
[0032] Particle stabilized emulsions, and more specifically, particle
stabilized
emulsions for extraction of hydrocarbons from oil sand and/or oil shale
formations are
provided. While certain embodiments are discussed, it will be understood by
those
skilled in the art made aware of this invention that any such embodiment can
independently pertain to the other or another such recovery process with
corresponding revision or adaptation to a particular recovery, subterranean
formation
and/or particular end-use application, and can be applied thereto with
comparable
effect. One aspect of the invention relates to a process for recovering
hydrocarbons
from a subterranean formation by contacting or injecting an emulsion of
aqueous
liquid in liquid or supercritical carbon dioxide (aqueous-in-CO2 [A/C]
emulsion more
commonly referred to as water-in-CO2 emulsion [W/C]) stabilized by fine
hydrophobic particles, with or into the formation. Another aspect of the
invention
relates to the process for recovering hydrocarbons from a subterranean
formation by
contacting or injecting an emulsion of liquid or supercritical carbon dioxide
(C02-in-
aqueous [C/A] emulsion more commonly referred to as C02-in-water emulsions
[C/W]) stabilized by fine hydrophilic particles, with or into the formation.
[0033] As understood in the art, an "emulsion" is a stable mixture of at least
two immiscible liquids. In general, mixing or dispersing immiscible liquids
(one
phase into the other) creates an unstable dispersion, which tends to separate
back into
two distinct phases. An emulsion is thus stabilized by the addition of an
"emulsifying
agent" which functions to reduce surface tension between at least two
immiscible
liquids. As used herein, an "emulsifying agent" defines a substance that, when
combined with a first component defining a first phase, and a second component
defining a second phase immiscible with the first phase, will facilitate
assembly of a
stable dispersion of the first and second phases.
[0034] Emulsions described herein may be stabilized by particles. The
particles
may orient themselves around the droplets according to their hydrophilicity or
hydrophobicity. For instance, in A/C emulsions, a part of the hydrophobic
particles
may be wetted by the continuous carbon dioxide phase. Conversely, with C/A
emulsions, the hydrophilic particles may be wetted by an aqueous continuous
phase.
9

CA 02765788 2011-12-15
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The sheath of particles surrounding the droplets can prevent the coalescence
of either
carbon dioxide or water droplets into a continuous phase. In C/A emulsions, a
larger
part of the hydrophilic particles may be wetted by the continuous aqueous
phase. As
discussed below, the invention comprises many types of aqueous systems
including
water that is distilled, deionized, artesian, sea, waste, brine, oil- and gas-
well
associated or formation water. Similarly, the invention comprises all sorts of
carbon
dioxide, pure liquid and supercritical carbon dioxide, as well as complex
mixtures and
complex liquids, such as liquid hydrogen sulfide, organic and inorganic
solvents
freely miscible with carbon dioxide.
[0035] Without restriction to any one theory or mode of operation, upon
injection into a subterranean formation, the emulsion disperses and
disintegrates. If,
for example, an A/C emulsion is injected, the liquid or supercritical carbon
dioxide
released therefrom can interact with the hydrocarbon component of the
formation,
dissolve at least a portion of it, at least partially reduces its viscosity
and leave behind
a slurry of fine particles in water. Further, as sand or other similar
granules of the
formation may be hydrophilic, there may be a preferential interaction with
water
rather than the hydrophobic hydrocarbon component, thereby allowing release of
the
tar, oil, bitumen and/or kerogen from the granules. As a result, water can
displace the
hydrocarbon component from the formation, mobilizing it for extraction and
recovery.
[0036] Alternatively, a similar process can be envisioned with respect to a
C/A
emulsion system. While liquid carbon dioxide is very sparingly soluble in
water (e.g.,
less than about 5 wt. % at low temperatures and relatively high pressures), up
to about
50 wt. % or more of a carbon dioxide component can be dispersed in water with
an
emulsion system of the sort described herein, using hydrophilic particulate
components. As discussed above, interaction of such a carbon dioxide (and/or
organic) component with an oil sand/oil shale formation can be used to promote
hydrocarbon extraction and recovery.
[0037] Accordingly, in one embodiment, a method of recovering or extracting a
hydrocarbon from an oil sand and/or oil shale formation is provided. The
method
comprises introducing an emulsion comprising supercritical C02, an aqueous
liquid,
and an emulsifying agent comprising particles, into such formation or in
contact with

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sand or shale excavation therefrom, and extracting hydrocarbon. In some cases,
the
emulsion comprises supercritical CO2 and an aqueous liquid. For example, the
emulsion may comprise a continuous phase comprising supercritical CO2 and a
dispersed phase comprising an aqueous liquid.
[0038] In another embodiment, such a method comprises contacting an
emulsion comprising a continuous phase including greater than about 1 % by
weight of
liquid C02, a dispersed phase comprising an aqueous liquid, and an emulsifying
agent
comprising particles, with oil sand and/or oil shale, and extracting
hydrocarbon
deposit(s) therefrom.
[0039] In another embodiment, a related system is provided. The system
comprises supercritical C02, an aqueous liquid, and particles in fluid
communication
with an emulsion forming apparatus for forming an emulsion comprising the CO2
component, aqueous liquid, and particles. The system also includes an
apparatus for
introducing the emulsion into a formation or contacting material excavated
therefrom
and an apparatus for recovering hydrocarbons. In one embodiment, the emulsion
formed by such a system comprises a continuous phase comprising supercritical
CO2
and a dispersed phase comprising an aqueous liquid.
[0040] In another embodiment, a related system comprises liquid C02, an
aqueous liquid, and particles in amounts sufficient to form an emulsion
comprising a
continuous phase including greater than about 1% by weight of liquid C02, a
dispersed phase comprising an aqueous liquid, and an emulsifying agent
comprising
particles. The liquid C02, aqueous liquid, and particles may be in fluid
communication with an emulsion forming apparatus. The system also includes an
apparatus for introducing the emulsion into a formation or contacting an
excavation
thereof and an apparatus for recovering hydrocarbon. In one embodiment, the
emulsion formed by such a system comprises a continuous phase comprising
greater
than about 1% by weight of liquid CO2 and a dispersed phase comprising an
aqueous
liquid.
[0041 ] In another aspect, whether method or system-related, a series of
emulsions are provided. In one embodiment, the emulsion comprises a plurality
of
droplets of an aqueous liquid suspended in a continuous phase comprising
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supercritical CO2, and an emulsifying agent comprising particles. In another
embodiment, an emulsion comprises a plurality of droplets of an aqueous liquid
suspended in a continuous phase comprising greater than about I% by weight of
liquid CO,, and an emulsifying agent comprising particles.
[0042] In another embodiment, a method of this invention comprises extracting
a hydrocarbon component from a mixture. The method comprises introducing an
emulsion comprising supercritical C02, an aqueous liquid, and an emulsifying
agent
comprising particles, into a mixture containing a hydrocarbon, and extracting
the
hydrocarbon from the mixture. In some cases, the emulsion comprises
supercritical
CO2 and an aqueous liquid. For example, the emulsion may comprise a continuous
phase comprising supercritical CO2 and a dispersed phase comprising an aqueous
liquid.
[0043] In another embodiment, such a method of extracting a hydrocarbon from
a mixture comprises introducing an emulsion comprising a continuous phase
including
greater than about 1% by weight of liquid C02, a dispersed phase comprising an
aqueous liquid, and an emulsifying agent comprising particles, into a mixture
of
components, and extracting a hydrocarbon component from the mixture. In one
embodiment, the emulsion comprises a continuous phase comprising greater than
about 1% by weight of liquid CO2 and a dispersed phase comprising an aqueous
liquid.
[0044] In another aspect, a related system for recovering a hydrocarbon
component from a mixture is provided. In one embodiment, the system comprises
supercritical C02, an aqueous liquid, and particles in fluid communication
with an
emulsion-forming apparatus for forming an emulsion comprising the
supercritical
C02, aqueous liquid, and particles. The system also includes an apparatus for
introducing the emulsion into a mixture of components, and an apparatus for
recovering a hydrocarbon component from the mixture. In some cases, the
emulsion
of such system comprises supercritical CO2 and an aqueous liquid. For example,
the
emulsion may comprise a continuous phase comprising supercritical CO2 and a
dispersed phase comprising an aqueous liquid.
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[0045] In one embodiment, a related system for recovering a hydrocarbon
component from a mixture comprises liquid C02, an aqueous liquid, and
particles in
amounts sufficient to form an emulsion comprising a continuous phase including
greater than about 1% by weight of liquid CO2. The system also includes a
dispersed
phase comprising an aqueous liquid, and an emulsifying agent comprising
particles.
The liquid CO2, aqueous liquid, and particles are in fluid communication with
an
emulsion-forming apparatus, an apparatus for introducing the emulsion into a
mixture
of components, and an apparatus for recovering a hydrocarbon component from
the
mixture. In some cases, the emulsion comprises a continuous phase comprising
greater than about I% by weight of liquid CO2 and a dispersed phase comprising
an
aqueous liquid.
[0046] As shown in the embodiment illustrated in FIG. 1, an emulsion 8
includes droplets 10 (also known as "globules") of a dispersed phase 14 (i.e.,
the
isolated phase stabilized by an emulsifying agent). In some embodiments, the
dispersed phase can comprise an aqueous liquid (e.g., water or aqueous
solutions). In
certain embodiments in which the dispersed phase comprises an aqueous liquid,
a
continuous phase 18 can comprise supercritical or liquid carbon dioxide (i.e.,
an A/C-
type emulsion). Some emulsions may also include an oil or lipid component
forming
all, or portions, of a continuous phase (e.g., aqueous-in-oil [A/O] type
emulsions).
Examples of such emulsions are provided below. The droplets of the emulsion
are
stabilized by particles 22, which may include, for example, solid particles
such as
pulverized coal. The particles form a particle sheath at the interface of the
two phases,
preventing their coalescence into a bulk phase. Without limitation, such
particle
stabilized emulsions can be referred to or are commonly known as "Pickering
emulsions".
[0047] While in some embodiments, liquid or supercritical CO2 may form
substantially all of the continuous phase of A/C emulsions, the invention is
not so
limited, and it should be understood that A/C emulsions described herein can
have
other compositions. For example, as described in more detail below, A/C
emulsions
can also include other fluids in the continuous phase in addition to liquid or
supercritical CO2 (e.g., to form a ternary mixture). In certain embodiments
including
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A/C-type, the continuous phase, can include greater than about 1% by weight of
liquid
or supercritical CO2. For example, in some cases, the continuous phase can
include
between about 1- about 20%, about 20- about 50%, or about 50-100% by weight of
liquid or supercritical CO2.
[0048] As used herein "droplet" means an isolated phase having any shape, for
example cylindrical, spherical, ellipsoidal, tubular, irregular shapes, etc.
Droplets may
have an average cross-sectional dimension of greater than or equal to about 25
nm,
greater than or equal to about 50 nm, greater than or equal to about 100 nm,
greater
than or equal to about 250 nm, greater than or equal to about 500 nm, greater
than or
equal to about 1 micron, greater than or equal to about 5 gm, greater than or
equal to
about 10 gm, greater than or equal to about 50 gm, greater than or equal to
about
100 gm, greater than or equal to about 200 gm, greater than or equal to about
350 gm,
greater than or equal to about 500 gm, greater than or equal to about 700 gm,
greater
than or equal to about 800 gm, or greater than or equal to about 900 gm. The
droplet
size of a particular emulsion may depend, at least in part, on the size and
type of the
emulsifying particles, inter-particle interactions (e.g., steric
interactions),
concentration and composition of the continuous and dispersed phases, as well
as the
rate of shearing/mixing when forming the emulsion, as described in more detail
below.
[0049] In some embodiments, emulsions described herein have a CO2
continuous phase and an aqueous dispersed phase. For example, in one
embodiment,
an emulsion comprises a plurality of droplets of an aqueous liquid (e.g.,
water and
seawater) suspended in continuous phase comprising greater than 1 % by weight
of
liquid CO2, and an emulsifying agent comprising particles. For example, in
some
cases, the continuous phase can include between 1-20%, 20-50%, or 50-100% by
weight of liquid CO2. In some cases, the continuous phase consists essentially
of
liquid CO2.
[0050] Whether or not expressly indicated, all numbers expressing component
quantities, concentrations or proportions (e.g., weight percentages ratios and
factors of
ratios), dimensions, properties, reaction or process parameters or conditions,
and so
forth used in the specification and claims are to be understood as being
modified in all
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instances by the term "about." Accordingly, unless indicated to the contrary,
the
numerical values set forth in this specification and the attached claims are
approximations that may vary depending upon the desired properties sought to
be
obtained by the present invention. At the very least, and not as a limitation
of
application of the doctrine of equivalents to the scope of such claims, each
numerical
value should be construed in light of the number of reported significant
digits and by
applying ordinary rounding techniques.
[0051 ] In certain embodiments, particle stabilized aqueous-in-oil (A/O)
emulsions are contemplated. (Such emulsions are also known as water-in-oil
[W/O]
emulsions). As described below, an "oil" can include any liquid that is
immiscible
with an aqueous liquid such as water; that is, any liquid that, when admixed
with an
aqueous liquid, can form a two-phase mixture. In one embodiment, an emulsion
may
include a continuous phase comprising an oil (e.g., a hydrocarbon or
fluorocarbon)
and a dispersed phase comprising an aqueous liquid (e.g., water). Such
emulsions
may optionally comprise liquid or supercritical carbon dioxide with respect to
a
continuous phase thereof. An example of a particle stabilized aqueous-in-oil
emulsion
is shown in FIG. 2. In the illustrative embodiment of FIG. 2, emulsion 40
including
droplets 42 of water in a dodecane continuous phase 44. The droplets are
stabilized
by carbon black particles 48. In this particular embodiment, the droplets have
an
average size of 10-20 m.
[0052] The aqueous liquid of an emulsion can be any liquid miscible with
water; that is, any liquid that, when admixed with water, can form a single-
phase
solution. In some cases, the aqueous liquid can comprise one or more
additives, such
as salts (e.g., salts of alkali and/or alkali earth metals). Non-limiting
examples of
aqueous phase materials include, for example, water (e.g., purified water,
unpurified
water, distilled water, deionized water, artesian water, seawater, ground
water, well
water, waste water, brackish water, brine, oil- and gas-well associated water,
formation water, natural sources of water that may or may not contain
dissolved salts
or contaminants, etc.), methanol, ethanol, DMF (dimethylformamide), or DMSO
(dimethyl sulfoxide). Those of ordinary skill in the art can choose
appropriate

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aqueous liquid(s) for forming particle stabilized emulsions based on general
knowledge of the art in combination with description provided herein.
[0053] The oil portion of an emulsion can be any liquid that is immiscible
with
an aqueous liquid such as water. In some cases, the oil may include one or
more
additives such as a surfactant. Two classes of oils that may be used in
emulsions
described herein include hydrocarbons and halocarbons (e.g., fluorocarbons).
The
emulsion can be stable at any suitable temperature depending on the particular
application.
[0054] A hydrocarbon may include a linear, branched, cyclic, saturated, or
unsaturated hydrocarbon. The hydrocarbon can optionally include at least one
heteroatom (e.g., oxygen in the backbone of the compound to provide a
corresponding
ether). Non-limiting examples of hydrocarbons include methane, ethane (and,
e.g.,
dimethyl ether), propane, butane, pentane, hexane, heptane, octane, nonane,
decane,
undodecane, dodecane, and the like and corresponding available ethers. Higher-
order
hydrocarbons such as C10-C20 hydrocarbons can also be used. In some cases, a
continuous or dispersed phase of an emulsion can include mixtures of
hydrocarbons of
various chain lengths. The hydrocarbon may be, for example, a petroleum
hydrocarbon. In some cases, hydrocarbons recovered from an oil sand/oil shale
formation can be used in continuous phases of emulsions described herein.
Regardless, use of such water immiscible solvents such as dimethyl ether,
dodecane or
similar such organic solvents, can facilitate hydrocarbon extraction from a
particular
formation. For instance, use of such components, whether in conjunction with a
dispersed or continuous phase, can enable extraction at lower (e.g.,
atmospheric)
pressures, thereby improving extraction efficiencies. Likewise, as discussed
below,
such organic components can be used with good effect for in situ extraction.
[0055] A fluorocarbon may include any fluorinated compound such as a linear,
branched, cyclic, saturated, or unsaturated fluorinated hydrocarbon. The
fluorocarbon
can optionally include at least one heteroatom (e.g., in the backbone of the
component). In some cases, the fluorocarbon compound may be highly
fluorinated,
i.e., greater than 50% of the hydrogen atoms of the component are replaced by
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fluorine atoms. In other cases, the fluorocarbon is perfluorinated.
Halocarbons
including, for example, bromine or chlorine atoms, are also contemplated.
[0056] In certain embodiments, emulsions described here include liquid or
supercritical carbon dioxide in the continuous phases. Gaseous carbon dioxide
can
become liquid carbon dioxide when compressed or pressurized (e.g., above 5.1
atm).
Supercritical carbon dioxide can form when the carbon dioxide is brought above
its
critical temperature (31.1 C) and pressure (78.3 atm). Supercritical carbon
dioxide
behaves like a gas with respect to viscosity, and can expand to fill its
container like a
gas, but behave like a liquid with respect to density. Additionally, liquid
and
supercritical carbon dioxide can diffuse through solids like a gas, and
dissolve
materials like a liquid, because of their properties such as low viscosity,
high diffusion
rate, and little or no surface tension. For example, the viscosity of
supercritical carbon
dioxide is typically in the range of 20 to 100 Pa=s, whereas typical liquids
have
viscosities of approximately 500 to 1000 .tPa=s. Such properties make
supercritical
and liquid carbon dioxide useful for extraction processes.
[0057] The invention comprises all sorts of carbon dioxide, pure liquid and
supercritical carbon dioxide, complex mixtures, complex liquids, as well as
binary
liquids, such as liquid hydrogen sulfide, organic and inorganic solvents
freely miscible
with carbon dioxide.
[0058] In embodiments comprising liquid or supercritical carbon dioxide as
part
of a continuous phase of an emulsion, it should be understood that other
materials can
form at least a portion of that phase. Likewise, continuous or dispersed
phases
described herein may include one or more of the following non-limiting
examples of
supercritical fluids: water, methane, ethane, propane, ethylene, propylene,
methanol,
ethanol and acetone. Additionally and/or alternatively, the continuous or
dispersed
phase can also include liquids such as liquid nitrogen, liquid oxygen, liquid
hydrogen,
liquid argon, liquid helium, or other cryogenic liquids (i.e., liquefied gases
at very low
temperatures). Particle stabilized emulsions comprising a cryogenic liquid or
a
supercritical fluid as a continuous or dispersed phase, and an aqueous liquid
as a
continuous or dispersed phase are also provided.
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[0059] Liquids forming continuous and dispersed phases may have a range of
viscosities suitable for forming emulsions described herein. In some cases in
which
the continuous and/or dispersed phase comprises a supercritical or cryogenic
liquid,
for example, the viscosity of the liquid may be in the range of, e.g., between
10-200 Pa=s. For instance, in one embodiment, a continuous and/or dispersed
phase
consisting essentially of a supercritical or cryogenic liquid may have a
viscosity in the
above range. In another embodiment, a continuous and/or dispersed phase
comprising
a supercritical or cryogenic liquid (e.g., which may be dissolved in a liquid)
may have
a viscosity in the range of between 200-1,500 Pa=s. In yet another exemplary
embodiment, a continuous and/or dispersed phase comprising a liquid, but which
does
not comprise a supercritical or cryogenic liquid therein, may have a viscosity
in the
range of between 200-1,500 llPa=s. It should be understood, however, that any
suitable viscosity of a continuous and/or dispersed phase can be used to form
emulsions described herein and that the invention is not limited in this
respect.
[0060] In certain embodiments, the dispersed and/or continuous phase of an
emulsion may include one or more additives such as organic substances,
microbial
components (e.g., bacteria), minerals, undissolved particles, various
dissolved species,
gases, solvents, salts, and the like. Accordingly, in some embodiments,
emulsions
described herein include ternary or higher mixtures.
[0061 ] In certain embodiments, emulsions described herein are stabilized at
least in part by fine particles. Suitable particles include solid particles
that are at least
partially undissolved in the emulsion. The particles may be, for example,
naturally
occurring, synthetic, or modified. Particles can be held at the interface
between the
two phases of the emulsion by, e.g., van der Waals forces,
hydrophobic/hydrophilic
interactions, hydrogen bonding, ionic interactions, and the like.
[0062] The surface properties of the particles (e.g., wettability) determines,
at
least in part, use in conjunction with an aqueous-in-CO2 emulsion, in the case
of a
mixture of carbon dioxide (e.g., supercritical or liquid carbon dioxide) and
an aqueous
liquid. Particles having some hydrophobic character (e.g., ground Teflon'',
activated
carbon, carbon black, and pulverized coal) are preferentially wetted by the
carbon
dioxide phase; hence, they promote A/C-type emulsions. In some cases, the
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hydrophobic character of the particles is naturally occurring or inherent in
the
material. In other embodiments, however, particles can be treated by a process
such
as heating or coating, which can change the surface characteristics of the
materials.
For instance, particles can be partially, completely, or uniformly coated with
a
substance (e.g., a surfactant or polymer). Applicable surface properties of
the
particles can be measured by those of ordinary skill in the art by techniques
such as
contact angle measurements between, for example, particle, aqueous and carbon
dioxide three-component systems. Numerous representative particulate materials
are
summarized, below, with respect to type, preparation and source.
Material Preparation Source Type
Carbonate minerals Grinding/pulverizing/crystallizing Natural/chemical
Hydrophilic
Silicate minerals Grinding/pulverizing/crystallizing Natural/chemical
Hydrophilic
Clay minerals Natural Hydrophilic
Coated clays Chemical coating Natural+chemical Hydrophobic
Coal Grinding/pulverizing Natural Hydrophobic
Carbon black Pyrolysis Chemical Hydrophobic
Petrocoke Petroleum refining Chemical Hydrophobic
Teflon Synthetic Chemical Hydrophobic
Latex Synthetic Chemical Both
Polymer beads Synthetic Chemical Both
Proteins Natural Both
Cellulosic Grinding/pulverizing Natural Hydrophilic
Modified cellulose Chemical modification of surface Natural+chemical Both
Chitin Natural --Hydrophilic
Chitosan Chemical modification of surface Natural+chemical Both
Iron Grinding/pulverizing Hydrophilic
Iron oxide Gnnding/pulverizing/crystallizing Hydrophilic
Cadmium selenide Chemical
[0063] Particles described herein may have a variety of shapes and sizes. For
example, particles may be cylindrical, spherical, rectangular, triangular,
ellipsoidal,
tubular, rod-like, or irregularly shaped. Suitable sizes of the particles may
depend on
factors such as the particulate type of emulsion (e.g., a water-in-carbon
dioxide
emulsion), the components of the continuous and dispersed phases, and the size
of the
dispersed droplets in the medium. The size of the particles refers to the
length of the
shortest line (e.g., cross-sectional dimension) connecting two end points of
the particle
and passing through the geometric center of the particle. In some embodiments,
the
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average size of the particles used to form an emulsion is less than 100 gm,
less than
50 gm, less than 25 gm, less than 10 gm, less than 5 gm, less than 1 gm, less
than
500 nm, less than 250 nm, less than 100 nm, less than 50 rim, less than 10
rim, or less
than 5 nm.
[0064] In some instances, the average size of the particles used to form an
emulsion is chosen, at least in part, by the desired size of the dispersed
droplets of the
emulsion. For instance, in some embodiments, very small particles may not be
suitable for large droplets, as the particles may be dislodged from the
surface of large
droplets by Brownian motion. In other embodiments, large particles may not be
suitable for small droplets, as the particles may not be able to pack onto
small
droplets. Accordingly, in some cases, the particle size is adjusted to the
dispersed
droplet diameter. In certain embodiments, the average size of the particles
may be
5-50 times smaller than the average size of the dispersed droplets of the
emulsion. For
example, the average size of the particles may be at least 5, 15, 25, or 50
times smaller
than the average size of the dispersed droplets of the emulsion. The ratio of
particle
size to droplet size may be, for example, between 1:10 and 1:30 (e.g., between
1:10
and 1:20 or between 1:20 and 1:30). Of course, other ratios of particle size
to droplet
size may also be used.
[0065] Particles may include elemental metals (e.g., gold, silver, copper),
semi-
metals and non-metals (e.g., antimony, bismuth, graphite, sulfur), and/or
ceramics. In
some instances, particles can include, but not limited to, oxides, sulfides,
sulfates,
carbonates, silicates.
[0066] Particles can also include, but not limited to, polymer particles
(e.g., plastics) such as polycarbonates, polyethers, polyethylenes,
polypropylenes,
polyvinyl chloride, polystyrene, polyamides, polyacrylates, polymethacrylates,
polytetrafluoroethylene (Teflon`') and the like.
[0067] In one particular embodiment, particles from the following group of
materials can be used: carbon black, petrocoke, Teflon`, shale, surface-coated
clays,
silica and pulverized coal. It should be understood that the invention is not
limited to
the above mentioned particles, but any particle or group of particles that
facilitates the

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generation of an A/C and/or C/A emulsion as desired can be used in accordance
with
the invention.
[0068] In certain embodiments of the invention, an emulsion can be stabilized
by both particles and a surfactant, which act as emulsifying agents to
stabilize at least
two immiscible phases. A variety of surfactants is known in the art and may
include,
for example, anionic, cationic, zwitterionic, and non-ionic species.
[0069] Those of ordinary skill in the art can also choose an appropriate
emulsifying agent by, for example, choosing the components used to form the
continuous and dispersed phases of the emulsion and knowing the surface
properties
(e.g., wettability) and/or likelihood of reactivity between the emulsifying
agent and
the two phases, and/or by a simple screening test. For example, if a water-in-
carbon
dioxide emulsion is desired, a suitable emulsifying agent (e.g., particles)
may include
one that is hydrophobic such that it can be wetted by the continuous carbon
dioxide
phase. One simple screening test may include mixing one set of components in a
vial
to forni the emulsion and determining the stability of the emulsion. Either
the
material composition, quantities, and/or concentration of one component can
then be
varied while keeping the others constant, and the stability of this emulsion
can then be
measured. Other simple tests can be conducted by those of ordinary skill in
the art.
[0070] Emulsions described herein are, according to some embodiments, stable
for at least about 1 minute. Emulsions that are stable over time are useful
because
they allow for the time necessary to transport, place, and/or use the emulsion
before
coalescence or disintegration. For example, emulsions may be stable for more
than
1 minute, 1 hour, 1 day, 1 week, I month, or 1 year. As used herein, a "stable
emulsion" means that droplets of the emulsion do not coalesce, e.g., to form
larger
droplets, at a particular temperature and pressure resulting in two bulk
phases with a
meniscus between them. In one particular embodiment, an emulsion that can be
used
for hydrocarbon extraction from oil sand/oil shale is stable from the time of
formation
to the time of injection into or contact with the sand/shale.
[0071 ] Emulsions described herein can have any suitable ratio of continuous
and dispersed phases. Typically, however, the volume of the continuous phase
is
greater than that of the dispersed phase. For example, the ratio of the
volumes of the
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continuous phase to dispersed phase may be greater than or equal to 1:1 up to
20:1
(e.g., between 1:1 and 5:1, between 5:1 and 10:1, or between 10:1 and 20:1).
It should
be understood, however, that any suitable ratio of volumes of continuous phase
to
dispersed phase can be used to form emulsions described herein and that the
invention
is not limited in this respect.
[0072] The amount of particles necessary for forming an emulsion may depend
on one or more of the following parameters: particle size, droplet size, type
of
emulsion formed, shape of the particles (which, in turn, may effect inter-
particle or
steric interactions), concentration and composition of the continuous and
dispersed
phases, and physical parameters associated with forming the emulsion (e.g.,
shear
force, temperature, and pressure). Accordingly, various amounts of particles
relative
to the amount of dispersed and/or continuous phase may be used to form
emulsions
described herein. In certain embodiments, the mass ratio of particle to carbon
dioxide
may be, for example, greater than or equal to 0.005:1 up to 1.0:1 (e.g.,
between
0.005:1 and 0.2:1, between 0.2:1 and 0.6:1, or between 0.6:1 and 1.0:1).
[0073] In some embodiments, the amount of particles added to two immiscible
phases of an emulsion can be greater than that which is necessary to form the
emulsion, and a portion of the particles can accumulate, for example, at the
bottom of
a reactor. In addition, because not all particles are of uniform size and may,
in fact,
include a distribution of sizes (e.g., some may be too small to adhere to the
interface
of the continuous and dispersed phases, and some may be too big), higher mass
ratios
of particles to dispersed phase material may be used.
[0074] In some embodiments, the amount of particles necessary for emulsion
formation can be estimated from a particle sheath model (e.g., a monolayer or
multi-
layer sheath model). An example is given for liquid CO2 droplets in an aqueous
continuous phase and particles comprising CaCO3. Taking a droplet diameter of
100 gm, a sheath thickness of 2 gm (corresponding to a monolayer of Hubercarb
CaCO3 Q6 particles with mean size 2 gm), a liquid CO2 density at 15 C and 17
MPa
of 0.93 g/cm3, and a CaCO3 bulk density of 2.7, the mass ratio of CaCO3/CO2 is
estimated at 0.2:1. Because not all particles have a uniform size, different
ratios of
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CaCO3/CO2 may be used. For example, 0.4:1, that is, for every 1 kg of CO2, 0.4
kg of
pulverized limestone may be used as well as ratios down to 0.002:1.
[0075] Emulsions described herein may be formed using any suitable
emulsification procedure known to those of ordinary skill in the art. In this
regard, it
will be appreciated that the emulsions can be formed using methods/systems
such as
microfluidic systems (e.g., a microfluidizer), ultrasound, high pressure
homogenization, using a static mixer, shaking, stirring, spray processes, and
membrane techniques. In certain embodiments, emulsions described herein are
formed by shear forces. In the description herein concerning the use of
appropriate
methods of fabricating emulsions, those of ordinary skill in the art can
select suitable
materials, techniques, conditions (e.g., temperature and pressure) etc. based
upon the
particular application, general knowledge of the art and available reference
materials
concerning certain techniques for forming emulsions, in combination with the
description herein.
[0076] In one particular embodiment, emulsions described herein are formed
using a high-pressure batch reactor, as shown in FIG. 3. As shown in the
embodiment
illustrated in FIG. 3, high-pressure batch reactor 50 can be used to form an
emulsion
comprising water and liquid or supercritical carbon dioxide as the continuous
or
dispersed phases. The reactor includes source of water 54 in fluid
communication
with vertical batch reactor 58. Electrical pump 60 can transport water from
the source
to the reactor via pipe 62, and this process which can be controlled at least
in part by
check valve 64 and/or release valve 66. As illustrated, source of carbon
dioxide 70 is
also in fluid communication with the reactor via pipe 72. Introduction of
carbon
dioxide into the reactor can be controlled by manual piston screw pump 74,
shut off
valves 76 and 78, and relief valve 80. The pressures in the pipes can be
measured by
gauges 82 and 86. Once water and carbon dioxide are introduced into reactor
58,
magnetic mixer assembly 88 can mix the components and form an emulsion. The
temperature inside the reactor can be measured by thermal couple and panel
meter 90.
Particles can be introduced into the reactor via an opening (not shown) in the
form of
a slurry or particles alone. System 100, or a similar system, can be used to
form a
23

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variety of emulsions including, but not limited to, C02-in-aqueous, aqueous-in-
CO2,
aqueous-in-oil, and oil-in-aqueous emulsions.
[0077] In another embodiment, a microfluidizer is used to form an emulsion.
The size and stability of the droplets produced by this method may vary
depending on,
for example, capillary tip diameter, fluid velocity, viscosity ratio of the
continuous
and dispersed phases, and interfacial tension of the two phases.
[0078] In another embodiment, a static mixer is used to form an emulsion. An
example of a static mixer is illustrated in FIG. 4. As shown in the embodiment
illustrated in FIG. 4, static mixer 92 is tubular and includes alternating
helical mixing
blades 96 with no moving parts. In some cases, the static mixer is a Kenics-
type static
mixer. The components of an emulsion (e.g., liquid or supercritical CO2,
particles,
and an aqueous liquid) can be introduced at an up-stream portion 94 of the
mixer, and
an emulsion formed of the components can exit at a down-stream portion 98. A
static
mixer can be incorporated into a static mixer emulsion apparatus, e.g., as
shown in
FIG. 5. The size and stability of the droplets produced by a static mixer may
vary
depending on, for example, the pressure differential between the up- and down-
stream
portions of the static mixer, the length of the mixer, the number of baffles
per unit
length of the mixer, and other variables (e.g., temperature).
[0079] In some embodiments of the invention, emulsions described herein are
used for extracting a component from a mixture of at least two components. The
component to be extracted may be in the form of a solid (e.g., particles), a
liquid
(e.g., oil), or a gas (e.g., methane). In some cases, the component may
include
impurities and/or can include more than one phase (e.g., solid contaminants in
a
liquid). The at least two components of the mixture may be of the same phase
(e.g., both solid, both liquid, or both gaseous) or may include different
phases (e.g., a
solid and a liquid, a solid and a gas, or a liquid and a gas).
[0080] FIG. 6 schematically illustrates a system and one or more associated
methods that can be used to recover a hydrocarbon from a subterranean
formation in
situ, that is, underground without removing the overground burden. As shown in
this
illustrative embodiment, system and related method(s) 100 include particles
102,
supercritical or liquid CO2 104 and aqueous liquid (e.g., water), which can be
in fluid
24

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communication with emulsion forming apparatus 112 for forming, for example,
aqueous-in-C02, or aqueous-in-oil emulsions. Once an appropriate emulsion is
formed, the emulsion may flow to injection apparatus 118 (e.g., an injection
well or
pump), which may introduce the emulsion into well 123 in the direction of
arrows
122.
[0081 ] Well 123 may be drilled from top layer 124 to bottom layer 125 of a
subterranean formation, and the intermediate layer may include oil sand and/or
oil
shale deposits 126 containing mixtures of bitumen and/or kerogen components.
Without limitation as to any one theory or mode of operation, when the
emulsion is
introduced into well 123, this produces areas of high pressure 127 and low
pressure
129; as a result, the emulsion flows in the direction of arrows 128 from well
123 to
well 130. Likewise, without limitation to any one theory or mode of operation,
the
carbon dioxide (or other oil) component, can dilute the hydrocarbon component,
reduce its density and/or increase its mobility, thereby mobilizing the
hydrocarbon
component in the direction of arrows 128. The remaining slurry of fine
particles in
water pushes out the diluted hydrocarbon. Such a process appears to be aided
by the
fact that water has a greater affinity for hydrophilic sand particles, than
for oil. As a
result, the aqueous component of the emulsion is exchanged with the
hydrocarbon
component on the sand or shale of the formation. The hydrocarbon extracted
from
formation/deposits 126, along with portions of the continuous and/or dispersed
phases
of the emulsion, can flow in the directions of arrows 132 to receiver 142
(e.g., a
producing well).
[0082] Regardless, as the resulting extracted mixture may include carbon
dioxide, a hydrocarbon and water (e.g., in the case of a water-in-CO2 emulsion
being
injected), separation of the components may be necessary or desired. A first
separation process can include the use of separator 146, which may separate
carbon
dioxide from the hydrocarbon and water. The carbon dioxide, which may now be
in
the form of a gas, can be recovered in container 154. If desired, this carbon
dioxide
can be recycled by transporting it to compressor/condenser 158, which can
compress
and/or condense the carbon dioxide to form supercritical or liquid CO2. This
compressed carbon dioxide can act as, or be added to, source of carbon dioxide
104.

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[0083] Once separator 146 removes CO2 from the extracted mixture, oil/gas and
water can be transported to separator 164, which can separate water from the
hydrocarbon component. Water separated from the mixture can be transported to
container 168, and can act as, or be added to, source of water 108 used in
forming the
emulsion. Additionally and/or alternatively, at least a portion of the water
can be
transported to a water disposal well. The hydrocarbon separated from separator
164
can be transported to storage facility 174 for future use or consumption. In
some
embodiments, at least a portion of the oil can act as, or be added to, source
of oil 109
used to form the emulsion.
[0084] Carbon dioxide 104 may be obtained commercially from sources such as
natural CO2 deposits, gas wells, CO2 separated from natural gas wells, from
separating
CO2 in the flue gas of fossil fuel combustion, from cement manufacturing, from
fermentation, from combustion of carbonaceous fuels, and as a by-product of
chemical processing where CO2 is a major by-product. For example, CO2 may be
obtained as a by-product from steam-hydrocarbon reformers used in the
production of
ammonia, gasoline, and other chemicals.
[0085] In the future, large amounts of CO2 may be obtained from a new
generation of coal based power plants. The new plants may use the principle of
integrated coal gasification combined cycle (IGCC) with CO2 capture. In these
plants,
coal is gasified to produce a synthetic gas comprising a mixture of carbon
monoxide
(CO) and hydrogen (H2). The CO is further reformed with steam to produce more
H2
and CO2. The CO2 is separated from H2 by one of several known technologies,
such as
physical absorption, chemical absorption, or membrane separation. The H2 is
used for
power generation in a combined cycle. The separated gaseous CO2 is liquefied
under
pressure and may be sequestered in subterranean formations, called geologic
sequestration. However, a part of the separated CO2 may become available to
form the
particle stabilized emulsions to be used for oil sand and/or oil shale
extraction as
described in this invention.
[0086] As described above, at least a portion of carbon dioxide 104 may be
recycled or recovered from the extraction process. Carbon dioxide may be
treated by
processes such as, for example, amine (MEA) treatment, adsorption processes,
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extractive distillation techniques, and membrane systems. Crude CO2
(e.g., containing at least 90% C02) can be compressed in either two or three
stages,
cooled, purified, and condensed to the liquid phase by a compressor/condenser.
The
carbon dioxide can then be placed in an insulated storage vessel.
[0087] If CO2 is imported to the oil sand/oil shale extraction site, it is
most
economical to transport the liquid carbon dioxide by pipeline. Alternatively,
the
carbon dioxide can be transported, for example, in high-pressure un-insulated
steel
cylinders, as a high-pressure liquid in insulated truck trailers or rail tank
cars, or as dry
ice in insulated boxes, trucks, or boxcars.
[0088] As described above, a variety of aqueous liquids can be used in
emulsions described herein. In one embodiment, water from a well on site of
the
subterranean formation can be used. In other embodiments, well water, sea
water, or
other sources of water can be imported. In yet another embodiment, waste water
from
an oil refinement process may be used in forming emulsions described herein.
Optionally, the water may be purified (e.g., filtered) to remove waste
materials,
contaminants, and the like, prior to formation of the emulsion.
[0089] In the embodiment illustrated in FIG. 6, particles 102, carbon dioxide
104, and aqueous liquid 108 (and/or oil) are shown as separate sources.
However, in
other embodiments, one or more materials can be premixed prior to forming an
emulsion. For example, in one embodiment the particles are mixed with water to
form
a slurry prior to formation of an emulsion with carbon dioxide. In another
embodiment, the particles are mixed with carbon dioxide to form a slurry prior
to
formation of an emulsion with another liquid. Other pre-mixtures of components
can
also be used. Regardless, such a methodology can be used for in situ
extraction of
hydrocarbons from a subterranean formation, e.g., oil sand or oil shale. A
stabilized
emulsion can be injected directly into the formation. When A/C emulsions are
used,
injection depth should be greater than about 200 meters. At shallower depths,
vaporization of a liquid carbon dioxide component would disintegrate the
emulsion.
However, as discussed above, A/O emulsions using an alternative organic
continuous
phase (e.g., dimethyl ether, dodecane, etc.) can be used at effectively
shallower
depths.
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[0090] In certain embodiments, for in situ hydrocarbon extraction
(e.g., petroleum) from oil sands or oil shale, as illustrated in FIG. 6, an
organic
component at least partially immiscible with an aqueous component, can be
injected
into the oil sand or oil shale formation prior to the injection of the
particle stabilized
emulsion of an aqueous fluid in carbon dioxide (A/C) or carbon dioxide in
aqueous
fluid (C/A). The organic component can, without limitation, be selected from
about
C2 to about C20 hydrocarbons (e.g., straight-chain, branched and/or cyclic
aliphatic
and aromatic compounds - - whether substituted or unsubstituted, saturated or
unsaturated), from about C2 to about C40 ethers and from combinations thereof.
The
prior injection of the said hydrocarbons or ethers can reside in the formation
from
about 1 hour, 1 week, 1 month to about 1 year before injection of the particle
stabilized emulsion. This embodiment may lead to greater petroleum extraction
efficiency compared to the co-injection of such an organic component together
with or
as a component of the A/C or C/A emulsion. This embodiment can be designated
"soak&puf"
[0091 ] One particular system for recovering hydrocarbons ex situ from
excavated oil sand and/or oil shale is shown in FIG. 7. In the illustrative
embodiment
shown in FIG. 7, an A/C or C/A emulsion can be contacted with excavated
sand/shale.
In the embodiment, a crusher 1 comminutes the oil sand or oil shale into beach
sand
size granules. The granules are fed via a hermetic feeder 2 into the contact
tower 3.
The contact tower must be kept under a sufficiently high pressure in order for
the
emulsion not to phase separate, and the liquid or supercritical CO2 flash into
a gas.
The particle stabilized A/C or C/A emulsion is prepared in the particle-water
mixer
4.The emulsion is injected into the contact tower via an emulsion forming
apparatus 5,
where it flows counter-current to the oil sand or oil shale granules. The
residual
tailings are discharged via a hermetic discharger 6 into a hopper 7, from
whence they
are transported away by truck or rail. The upward flowing emulsion extracts
and
dissolves the oil from the sand or shale granules and exits the top of the
contact tower
into a flash separator 9. where liquid or supercritical CO2 is flashed into
gaseous CO2,
which is liquefied in compressor 10 for eventual re-use. The extracted oil is
stored in
tank 11 for transport to the refinery. A liquid CO2 tank 12 stores the
necessary make-
28

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up liquid CO,. The emulsifying particles are stored in hopper 13. The
necessary water
for forming the emulsion comes from municipal water, surface water (river,
lake,
ocean) or associated water from oil and natural gas production.
[0092] In certain embodiments, for ex situ hydrocarbon extraction
(e.g., petroleum) from oil sands or oil shale, an organic component at least
partially
immiscible with an aqueous component, can be contacted with the excavated oil
sand
or oil shale in a contact tower, as illustrated in FIG. 7, rior to contact in
the tower of
the particle stabilized emulsion of an aqueous fluid in carbon dioxide (A/C)
or carbon
dioxide in aqueous fluid (C/A). The organic component can, without limitation,
be
selected from about C2 to about C70 hydrocarbons (e.g., straight-chain,
branched
and/or cyclic, aliphatic and aromatic compounds - - whether substituted or
unsubstituted, saturated or unsaturated), from about C2 to about C40 ethers
and from
combinations thereof. The prior contact of the said hydrocarbons or ethers can
reside
in the tower from about 1 minute, 1 hour, to about 1 week before contact in
the tower
of the particle stabilized emulsion. This embodiment may lead to greater
petroleum
extraction efficiency compared to the co-injection of such an organic
component
together with or as a component of the A/C or C/A emulsion. This embodiment
can
be designated "soak&extract. "
[0093] Figure 7 is but one of the possible ex situ extraction processes, and
is not
limited to this invention. For example, a batch reactor can be used for the
extraction
procedure. It is understood by those skilled in the art of ex situ oil
extraction that
either a continuous process, such as illustrated in FIGURE 7, or a batch
reactor, or a
combination thereof, using the extraction process based on A/C or C/A
emulsions is
part and parcel of this invention. Furthermore, when using water-immiscible
solvents
such as dimethyl ether, dodecane or other such solvents of the sort described
herein,
conventional, atmospheric pressure vessels can be used with good effect for
hydrocarbon extraction from oil sand or oil shale.
Examples of the Invention.
[0094] The following non-limiting examples and data illustrate various aspects
and features relating to the methods and/or systems of the present invention,
including
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the preparation of particle stabilized emulsions over range of physical
properties and
functional effects, as are available through the synthetic methodologies
described
herein. In comparison with the prior art, the present methods and/or systems
provide
results and data which are surprising, unexpected and contrary thereto. While
the
utility of this invention is illustrated through the use of several
methods/systems and
emulsions, together with various continuous and dispersed phases thereof, it
will be
understood by those skilled in the art that comparable results are obtainable
with
various other methods/systems and emulsions/continuous phases/dispersed
phases, as
are commensurate with the scope of this invention.
[0095] The following examples illustrate preparation of particle stabilized
emulsions, for use in oil sand, oil shale or related extraction methods,
according to
certain embodiments of the invention.
Example la
[0096] Particle stabilized aqueous liquid-in-CO2 (A/C) macroemulsions were
formed in a high pressure batch reactor (HPBR) with view windows using an
apparatus similar to the one shown in FIG. 3. The reactor included a stainless
steel
pressure cell of 85 mL internal volume equipped with tempered glass windows
(PresSure Products G03XCO1B). The windows were placed 180 apart, with one
illuminated with a 20 W, 12 V compact halogen bulb and the other allowing
observation with a video camera. The view window diameter was 25 mm. The
window diameter was used as a scale for determining droplet diameter sizes.
The
reactor was equipped with a pressure-relief valve (Swagelok R3-A), a
thermocouple
(Omega KMQSS-125G-6), a pressure gauge (Swagelok PGI-63B), a bleed valve
(Swagelok SS-BVM2), and a 3.2 mm port for admitting CO2. A cylindrical
magnetic
stir bar with a cross shape on top (VWR Spinplus) was utilized for internal
mixing.
Unless otherwise indicated, the stir bar rotated at 1300 rpm. Reactor
temperature was
adjusted by application of hot air from a heat gun or solid dry ice chips.

CA 02765788 2011-12-15
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Example lb
[0097] For preparation of A/C macroemulsions, the following procedure was
carried out: dry hydrophobic particles were added to the HPBR, followed by
injection
of liquid CO2. After agitation, a high-pressure syringe pump was used to
inject water
to a set pressure of 17.2 MPa. For the A/C emulsions, a proportion of -65 mL
of
C02/20 mL of H2O was used.
Example lc
[0098] For most particles used in these representative, non-limiting examples,
the particle size was determined from SEM images. In each frame, nearly all
particles
were counted and measured. For spherical particles, their diameter was
measured; for
crystalline or irregular particles, the average of two dimensions was taken,
one along
the long axis and the other along the short axis. The mean diameter was
estimated as
(dp)mean = [In, (dp) x d,]/NN (1)
where n, (dA) is the number of particles counted that have a size dp, and N,
is the total
number of particles counted. The mean size, (dp)mean, and standard deviation
of the
particles used in this study are tabulated in Table 1.
Example 1 d
[0099] For dispersed phase droplet size determination, the HPBR window
diameter (25 mm) was used as a scale. The diameter of droplets near the window
was
measured under magnification and compared with the window diameter.
Table 1. Mean Particle Size and (Standard Deviation) in um of Pulverized
Materials Used
for Stabilizing C/A and A/C Type Emulsions
(a) (hydrophilic)
particle limestone (Q6) limestone CaCO3 sand Si02 flyash shale lizardite
(Ql) (Fisher)
mean,
size 2 (1.7) 0.55 (0.4) 3.1 (1.6) 4.3 (5.7) 2.5 (3.4) 4.2 (6.0) 4.8 (3.9)
um
(b) Hydrophobic
particle carbon black' coal Teflon
mean, 0.12 4.2(4.4) 1.8 (1.0)
size m
a Manufacturer data;
31

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WO 2010/148204 PCT/US2010/038998
() standard deviation
[00100] The following examples provide results and observations relating
to the emulsions prepared above, and illustrate various properties and
functional
characteristics which can be utilized in the context of oil sand or shale oil
hydrocarbon
recovery. (For purpose of comparison, various representative hydrophilic
particles
and corresponding emulsions were prepared and characterized.)
Hydrophilic Particles.
Example 2a
[001011 Limestone. Both Hubercarb as mined pulverized limestone and
Fisher Chemical reagent-grade CaCO3 gave stable C/A macroemulsions. A C/A
macroemulsion formed with Hubercarb Q1 particles with mean particle size of
0.55
(0.4) gm, where the number in parentheses is the standard deviation. A non-
uniform
macroemulsion was formed, with heavier globules settling at the bottom of the
water
column, median-size globules being neutrally buoyant, and large globules
floating on
top of the water column. The large globules appeared to be partially covered
with a
sheath of particles.
[00102] A C/A macroemulsion stabilized by Hubercarb Q6 particles with
mean particle size of 2 (1.7) gm was formed. After thorough mixing and a rest
period,
most globules settled in the bottom of the pressure cell, indicating that the
globules
were heavier than the surrounding water. The globule diameter was in the range
of
200-300 gm.
[00103] Macroemulsions were also formed with supercritical CO2 and Q6
particles. The pressure in the cell was 17.2 MPa at a temperature of 45-47 C.
A
stable macroemulsion formed with a globule diameter in the 100-150 micron
range,
smaller than that with liquid CO2 under the same pressure and mixing
conditions.
Most globules settled in the bottom of the cell. Even though the density of
supercritical CO2 (-P800 kg m-3) is smaller than that of liquid CO2 (-930 kg M-
3 at
17.2 MPa and 15 C), the gross density of the supercritical globules was
greater than
that of the surrounding water.
[00104] Limestone particle-stabilized macroemulsions were also formed
in a solution of 3.5 wt % NaCI in deionized water. The globule diameter was
similar
32

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to that formed in deionized water alone, and all the initially present liquid
CO2 was
emulsified. However, no systematic measurements were performed on emulsion
yield
as a function of NaCl concentration.
[00105] Macroemulsions were also formed with Fisher Chemical C-65
reagent-grade CaCO3 (mean particle size 3.1 (1.6) m). Under mild mixing
conditions (400-500 rpm), rather large globules were formed, in the 500-800
micron
diameter range. The sheath of crystalline particles adhering to the surface of
CO2
droplets was clearly visible.
Example 2b
[00106] Sand. The milled and sieved sand particles had a mean particle
size of 4.3 (5.7) m. The large standard deviation indicates a wide
distribution of
particle size. The sand particles produced a stable C/A macroemulsion,
probably due
to the hydrophilic silica content of sand. The globule diameter was in the
200-300 micron range.
Example 2c
[00107] Fly ash. The unprocessed flyash particles had a mean particle
size of 2.5 (3.1) m. The large standard deviation indicates a wide
distribution of
sizes, but most particles were in the submicron to a few micron size range.
The size
of the particles, plus their hydrophilic character (similar to sand), was
conducive for
the formation of a stable C/A macroemulsion. The globule diameter was in the
80-150 micron range.
Example 2d
[00108] Shale. The pulverized shale had a mean particle size of 4.2 (6.0)
pm with a wide distribution of sizes. Pulverized shale produced a stable C/A
macroemulsion, probably due to the hydrophilic character of shale's major
ingredients,
clay minerals and quartz. The globule diameter was in the 80-150 micron range.
Because of the small bulk density of shale (2.0-2.2 g/cm3), most pulverized
shale-
sheathed globules floated on top of the water column.
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Example 2e
[00109] Magnesium Silicate. The pulverized lizardite had a mean particle
size of 4.8 (3.9) gm. The appropriate particle size and the hydrophilic
character of
magnesium silicate produced a stable C/A macroemulsion. The globule diameter
was
in the 80-130 micron range.
Hydrophobic Particles.
Example 3a
[00110] Teflon. Teflon`' powder is strongly hydrophobic. One gram of
the powdered resin produced an aqueous liquid-in-carbon dioxide (A/C)
macroemulsion, where water is the dispersed phase and CO2 is the continuous
phase.
Water droplets sheathed with Teflon particles were evident, and no phase
separation
occurred during several hours of observation, which indicates that a stable
A/C
macroemulsion was formed.
Example 3b
[00111] Activated Carbon. When activated carbon (AC) was dispersed in
liquid CO2 under pressure, the AC agglomerated into clumps. Under the
conditions
employed, upon addition of water and stirring, a black mass ensued in which it
was
difficult to discern distinct globules.
Example 3c
[00112] Carbon Black. Carbon black (CB) did disperse in liquid CO2
without agglomeration. Upon addition of water with stirring, a black,
inscrutable
liquid ensued. However, no phase separation occurred after several hours of
observation, suggesting that a stable A/C emulsion was formed.
Example 3d
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[00113] Coal. Pulverized coal also dispersed readily in liquid CO2
without agglomeration. Upon addition of water with stirring, a A/C
macroemulsion
was formed where water droplets were sheathed with coal particles dispersed in
C02-
Example 4a
[00114] The example shows that particle stabilized emulsions described
herein can be used to extract or remove oil from oil sand or shale oil. As
shown in
FIG. 8A, , embodiment 200 includes a mixture of oil and sand. A water-in-oil
emulsion comprising a dodecane continuous phase (having an average droplet
size of
50-100 gm) and a water dispersed phase stabilized by Teflon`s particles
(average size
of 1.8 gm) was injected into tube 206 in the direction of arrow 208. Tube 206
extended to the bottom of column 207. As the emulsion exited tube 206 and
flowed
back up column 207 in the direction of arrow 209, oil was extracted from the
mixture
of sand and oil. This extraction process resulted in a relatively clean sand
212 (i.e.,
substantially free of oil), and extracted oil phase 214 as a mixture of oil
and dodecane.
Example 4b
[00115] As shown in the comparative example of FIG. 8B, a similar
process as described for FIG. 8 was used, except a mixture of oil and sand was
extracted using alternating dodecane and water instead of an emulsion of
dodecane
and water. This extraction process resulted in embodiment 210 including a
smaller oil
and dodecane phase 220 (compared to that of FIG. 8A), water phase 222, and a
mixture of oil and sand 224.
[00116] This example shows that particle stabilized dodecane and water
emulsions are more effective in extracting oil from sand and oil mixtures than
non-
emulsions comprising dodecane and water.
[00117] As demonstrated, the emulsion technology of this invention
improves upon the currently practiced extraction method using hot water
frothing on
account of the greater extraction efficiency of liquid or supercritical CO2 or
other
solvents. Emulsions of Water-in-CO2 (W/C) or Water-in-Oil (W/O) stabilized by
fine
particles can disperse as much as 50% by volume water in liquid or
supercritical CO2

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or other solvents, whereas less than a few percent by volume water can be
dissolved in
liquid or supercriticalCO2 or other solvents. Laboratory experiments showed
that
crude oil is readily displaced from the pores of oil sand or oil shale when
using
particle stabilized W/C or W/O emulsions. Because the surface of sand or shale
granules is hydrophilic, the water readily adsorbs in place of the extracted
crude oil.
In addition, the emulsion components can be recycled, thus reducing water use
requirements and otherwise significantly lowering the material costs inherent
in the
currently practiced hot water frothing methods. Particle stabilized emulsions
of
Water-in-CO2 provide greater extraction efficiencies than water alone, CO2
alone, or
Water-Alternate-Gas (WAG) methods.
[00118] 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. For instance, it will be understood by those skilled in the art
that various
other emulsions can be used in conjunction with this invention, such emulsions
including carbon dioxide and/or oil in aqueous emulsions, with corresponding
modification to the methods/apparatus and/or systems described herein. 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. 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,
36

CA 02765788 2011-12-15
WO 2010/148204 PCT/US2010/038998
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.
37

Dessin représentatif
Une figure unique qui représente un dessin illustrant l'invention.
États administratifs

2024-08-01 : Dans le cadre de la transition vers les Brevets de nouvelle génération (BNG), la base de données sur les brevets canadiens (BDBC) contient désormais un Historique d'événement plus détaillé, qui reproduit le Journal des événements de notre nouvelle solution interne.

Veuillez noter que les événements débutant par « Inactive : » se réfèrent à des événements qui ne sont plus utilisés dans notre nouvelle solution interne.

Pour une meilleure compréhension de l'état de la demande ou brevet qui figure sur cette page, la rubrique Mise en garde , et les descriptions de Brevet , Historique d'événement , Taxes périodiques et Historique des paiements devraient être consultées.

Historique d'événement

Description Date
Demande non rétablie avant l'échéance 2014-06-17
Le délai pour l'annulation est expiré 2014-06-17
Réputée abandonnée - omission de répondre à un avis sur les taxes pour le maintien en état 2013-06-17
Inactive : CIB enlevée 2012-09-26
Inactive : CIB en 1re position 2012-09-26
Lettre envoyée 2012-07-26
Inactive : Correspondance - PCT 2012-07-04
Inactive : Transfert individuel 2012-07-04
Inactive : Page couverture publiée 2012-02-23
Inactive : Notice - Entrée phase nat. - Pas de RE 2012-02-10
Demande reçue - PCT 2012-02-09
Inactive : CIB attribuée 2012-02-09
Inactive : CIB attribuée 2012-02-09
Inactive : CIB attribuée 2012-02-09
Inactive : CIB en 1re position 2012-02-09
Exigences pour l'entrée dans la phase nationale - jugée conforme 2011-12-15
Demande publiée (accessible au public) 2010-12-23

Historique d'abandonnement

Date d'abandonnement Raison Date de rétablissement
2013-06-17

Taxes périodiques

Le dernier paiement a été reçu le 2012-06-01

Avis : Si le paiement en totalité n'a pas été reçu au plus tard à la date indiquée, une taxe supplémentaire peut être imposée, soit une des taxes suivantes :

  • taxe de rétablissement ;
  • taxe pour paiement en souffrance ; ou
  • taxe additionnelle pour le renversement d'une péremption réputée.

Les taxes sur les brevets sont ajustées au 1er janvier de chaque année. Les montants ci-dessus sont les montants actuels s'ils sont reçus au plus tard le 31 décembre de l'année en cours.
Veuillez vous référer à la page web des taxes sur les brevets de l'OPIC pour voir tous les montants actuels des taxes.

Historique des taxes

Type de taxes Anniversaire Échéance Date payée
Taxe nationale de base - générale 2011-12-15
TM (demande, 2e anniv.) - générale 02 2012-06-18 2012-06-01
Enregistrement d'un document 2012-07-04
Titulaires au dossier

Les titulaires actuels et antérieures au dossier sont affichés en ordre alphabétique.

Titulaires actuels au dossier
UNIVERSITY OF MASSACHUSETTS
Titulaires antérieures au dossier
DAN S. GOLOMB
DAVID K. RYAN
EUGENE F. BARRY
MICHAEL J. WOODS
PETER A. SWETT
Les propriétaires antérieurs qui ne figurent pas dans la liste des « Propriétaires au dossier » apparaîtront dans d'autres documents au dossier.
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Description du
Document 
Date
(yyyy-mm-dd) 
Nombre de pages   Taille de l'image (Ko) 
Revendications 2011-12-14 3 151
Abrégé 2011-12-14 1 71
Description 2011-12-14 37 1 937
Dessin représentatif 2012-02-12 1 40
Page couverture 2012-02-22 1 71
Dessins 2011-12-14 8 620
Avis d'entree dans la phase nationale 2012-02-09 1 206
Rappel de taxe de maintien due 2012-02-19 1 111
Courtoisie - Certificat d'enregistrement (document(s) connexe(s)) 2012-07-25 1 126
Courtoisie - Lettre d'abandon (taxe de maintien en état) 2013-08-11 1 172
PCT 2011-12-14 7 285
Correspondance 2012-07-03 1 46