Note: Descriptions are shown in the official language in which they were submitted.
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METHODS FOR OIL EXTRACTION
FIELD OF INVENTION
The present invention relates to the extraction of heavy oils.
BACKGROUND
All publications herein are incorporated by reference to the same extent as if
each individual publication or patent application was specifically and
individually
indicated to be incorporated by reference. The following description includes
information that may be useful in understanding the present invention. It is
not an
admission that any of the information provided herein is prior art or relevant
to the
presently claimed invention, or that any publication specifically or
implicitly
referenced is prior art.
Oil sands (also known as tar sands) are a mixture of primarily sand, bitumen
and water. Each grain of oil sand may have three layers: an "envelope" of
water
surrounding a grain of sand, with bitumen surrounding the water to form the
outer
layer. Hence, "oil-wetted" and conversely it can also be "water-wetted". Other
materials, such as clay, may be present among the sand, bitumen and water.
Bitumen, in its raw state, is a heavy, viscous crude oil that frequently
contains high
amounts of sulfur. Bitumen found in Utah is known to generally contain lower
amounts of sulfur.
Oil shale is a sedimentary rock that contains solid bituminous materials. The
bitumen may be released through the process of pyrolysis when the rock is
heated.
There are two techniques currently used to extract bitumen: terrain mining
with trucks, crushing and processing, and sub-terrain mining, by thermal
recovery;
for example using steam. For terrain mining, massive open-pit mines are
constructed, along with associated extraction facilities to separate the
bitumen from
the sand_ For sub-terrain operations, drilling wells are made and steam is
injected to
heat the bitumen, allowing it to flow and to be pumped from a well.
Bitumen is sold in two general forms: raw and synthetic crude oil ("SCO"). In
its raw form, the bitumen is blended with a diluent to produce a "bitumen
blend"
because in its raw form, bitumen is too viscous to transport by conventional
pipeline.
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Diluents used for the blend are often less viscous hydrocarbons, most commonly
a
very light natural gas condensate (C5+ or "pentanes plus"). Furthermore, the
diluent
is a costly, fully processed, light crude oil. The bitumen blend is sold to
refineries
and competes with conventional heavy oils. As SCO, the bitumen has been
upgraded. SCO is also sold to conventional refineries and competes with
conventional medium and light oils.
Further, crude oil development and production may include three phases:
primary recovery, secondary recovery and tertiary (also known as enhanced)
recovery. Primary recovery involves the utilization of the natural pressure of
an oil
reservoir or gravity to drive oil into the welibore and lift technologies,
(e.g., pumps) to
bring the oil to the surface. However, only a small percentage (about 10%) of
an oil
reservoir's oil is typically produced during this phase. During the secondary
recovery, techniques such as injecting water or gas to displace the oil and to
drive it
to a welibore are used. Secondary recovery may result in recovering about 20-
40%
of the original oil. Tertiary or.enhanced oil recovery techniques have been
used and
may result in the recovery of about 30-60% of the original oil.
The use of carbon dioxide (C02) has had some success in enhanced oil
recovery. However, CO2 floods frequently have poor sweeping efficiency caused
by
gas fingering and gravity override. Poor sweep efficiency results from a high
mobility
ratio caused by the low viscosity of high-density COZCOmpared to that of water
or oil
Water injection alternating with gas is a common process used for mobility
control
during CO2floods. However, the effectiveness of this altemation is reduced by
gravity segregation between water and CO2and by permeability differences.
While there are methods known in the art to extract bitumen, there exists a
need in the art to extract this valuable resource in a more efficient, safe
and
environmentally friendly manner. Further, there is a need in the art to
further
enhance the recovery of oil from oil reservoirs.
SUMMARY OF THE INVENTION
The following embodiments and aspects thereof are described and illustrated
in conjunction with compositions and methods which are meant to be exemplary
and
illustrative, not limiting in scope.
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One embodiment of the present invention provides for a method for extracting
heavy oil from an oil reservoir, comprising: providing a solvent comprising
sodium
silicate, a salt or an equivalent thereof; injecting the solvent into the oil
reservoir; and
extracting the heavy oil from the oil reservoir. In one embodiment, the heavy
oil may
comprise bitumen. In one embodiment, the solvent may further comprise soy
flour,
lignin flour and/or citrus pectin. In another embodiment, the solvent may
further
comprise detergent-like surfactants. In another embodiment, the method may
further
comprise heating the solvent prior to injecting the solvent. In another
embodiment,
the method may further comprise injecting steam into the oil reservoir.
Another embodiment of the present invention provides for a method for
extracting bitumen from an oil sands reservoir, comprising: providing a
solvent
comprising sodium silicate, a salt or an equivalent thereof; injecting the
solvent into
the oil sands reservoir; extracting a slurry comprising oil sands from the oil
sands
reservoir; and extracting the bitumen from the slurry. In one embodiment, the
solvent may further comprise soy flour, lignin flour and/or citrus pectin. In
another
embodiment, the method may further comprise heating the solvent prior to
injecting
the solvent. In another embodiment, the method may further comprise injecting
steam into the oil reservoir. In one embodiment, extracting the bitumen may
comprise separating the bitumen from an inorganic material that exists in the
slurry.
In one embodiment, separating the bitumen from the inorganic material may
comprise adding a quantity of air to the slurry. In another embodiment
separating
the bitumen from the inorganic material may comprise adding a quantity of the
solvent to the slurry. In another embodiment, the method may further comprise
passing the slurry through a stripper to remove air bubbles. In another
embodiment,
the method may further comprise separating the bitumen from the solvent. In
one
embodiment, separating the bitumen from the solvent may comprise placing the
slurry through a counter-current decantation circuit.
Another embodiment of the present invention provides for a method for
extracting bitumen from terrain oil sands or oil shale, comprising: removing
the oil
sands or oil shale from the terrain; providing a solvent comprising sodium
silicate, a
salt or an equivalent thereof; adding the solvent to the removed oil sands or
oil shale
to create a slurry; and extracting bitumen from the slurry. In one embodiment,
the
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solvent may further comprise soy flour, lignin flour and/or citrus pectin. In
one
embodiment, the method may further comprise reducing the size of the removed
oil
sands or oil shale. In one embodiment, extracting the bitumen may comprise
separating the bitumen from an inorganic material that exists in the slurry.
In one
embodiment, separating the bitumen from the inorganic material may comprise
adding a quantity of air to the slurry. In another embodiment, separating the
bitumen
from the inorganic material may comprise adding a quantity of the solvent to
the
slurry. In another embodiment, the method may further comprise passing the
slurry
through a stripper to remove air bubbles. In another embodiment, the method
may
further comprise separating the bitumen from the solvent. In one embodiment,
separating the bitumen from the solvent may comprise placing the slurry
through a
counter-current decantation circuit. In one embodiment, removing the oil sands
or oil
shale may comprise: providing a solvent comprising sodium silicate, a salt or
an
equivalent thereof; using the solvent to fluidize the oil sands or oil shale;
and
pumping the fluidized oil sands or oil shale out of the terrain.
Other features and advantages of the invention will become apparent from the
following detailed description, taken in conjunction with the accompanying
drawings,
which illustrate, by way of example, various features of embodiments of the
invention.
BRIEF DESCRIPTION OF THE FIGURES
Exemplary embodiments are illustrated in referenced figures. It is intended
that the embodiments and figures disclosed herein are to be considered
illustrative
rather than restrictive.
Figure 1 depicts an oil sands processing flow diagram in accordance with
various embodiments of the present invention.
Figure 2 depicts a terrain mining flow diagram in accordance with an
embodiment of the present invention.
Figure 3 depicts sub-terrain mining with heated steam, in accordance with
various embodiments of the present invention.
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Figure 4 depicts a flow diagram detailing the extraction of the bitumen from
oil
sands mined from the terrain in accordance with an embodiment of the present
invention. In one embodiment the violent agitation of the slurry is optionai.
Figure 5 depicts a flow diagram showing the process for the separation of
bitumen from the froth in accordance with an embodiment of the present
invention.
DESCRIPTION OF THE INVENTION
All references cited herein are incorporated by reference in their entirety as
though fully set forth. Unless defined otherwise, technical and scientific
terms used
herein have the same meaning as commonly understood by one of ordinary skill
in
the art to which this invention belongs. Singleton et al., Dictionary of
Microbiology
and Molecular Biology 3'd ed., J. Wiley & Sons (New York, NY 2001); and March,
Advanced Organic Chemistry Reactions, Mechanisms and Structure 5ffi ed., J.
Wiley
& Sons (New York, NY 2001) provide one skilled in the art with a general guide
to
many of the terms used in the present application.
One skilled in the art will recognize many methods and materials similar or
equivalent to those described herein, which could be used in the practice of
the
present invention. Indeed, the present invention is in no way limited to the
methods
and materials described. For purposes of the present invention, the following
terms
are defined below.
"Beneficial microbe" as used herein refers to microorganisms that have
capabilities to impart beneficial properties to their surrounding environment.
"Beneficial capabilities" include, but are not limited to the ability digest,
dissolve,
break up, remove, decompose, or degrade materials. Examples of materials
include
but are not limited to arsenic, metals in tailings, methyl tertiary butyl
ether ("MTBE"),
waste material and hydrocarbon-based material, such as oil. Examples of such
microbes include, but are not limited to probiotics, bacteria, fungus, yeast
and algae.
"Probiotics" as used herein refers to beneficial bacteria or yeast. Examples
of
probiotics include but are not limited to Bifidobacterium, including,
Bifidobacterium
bifidum, Bifidobacterium breve, Bifidobacterium infantis, Bifidobacterium
longum;
Lactobacillus, including, Lactobacillus acidophilus, Lactobacillus bulgaricus,
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Lactobacillus casei, Lactobacillus plantarum, Lactobacillus rhamnosus,
Lactobacillus
GG; Streptococcus thermophilus, Enterococcus and Saccharomyces boulardii.
"Degreasing composition" as used herein refers to an organic or inorganic
composition that is able to dissolve, break up, remove, decompose, or degrade
hydrocarbon-based substances. The degreasing composition may exist as a solid,
liquid or gas.
"Fluidize" as used herein refers to enabling the non cohesion of a mass and
its ability to flow, even if such flow is of non-uniform size or lumpy.
Fluidize does not
necessarily mean that the oil sands or oil shale are reduced to a particular
size.
Indeed, it is contemplated that large lumps may exist within what is referred
to as
fluidized.
"Heavy oil" as used herein refers to crude oil with high viscosity and high
specific gravity. Although not required, heavy oils typically have low
hydrogen to
carbon ratios, high asphaltene, sulfur, nitrogen, heavy-metal content, and/or
acid
numbers. Typically, but not required, heavy oils have a viscosity above lOcP
and a
specific gravity below 22.3 API.
"Waterflood" as used herein refers to a method of extracting oil from a
reservoir where water and/or a liquid is injected into the reservoir to
displace the oil
in the reservoir.
"Wellbore" as used herein refers to the open portion of an oil well where the
oil from the reservoir may enter.
Various embodiments of the present invention provide for methods for oil
extraction. In one embodiment, the oil is heavy oil. In a particular
embodiment, the
oil is bitumen.
In one embodiment of the present invention, a waterflood with a solvent is
utilized to extract the oil. The method comprises providing a solvent;
injecting the
solvent into an oil reservoir; and extracting the oil from the oil reservoir.
Extracting
the oil from the oil reservoir may be performed by any known technology in the
art;
for example, by utilizing lifting technologies (e.g., pumps). While not
wishing to be
bound by any particular theory, the inventors believe that the solvent reduces
the
viscosity of the oil and allows it to move more easily toward production
wells.
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In one embodiment, the solvent may comprise a degreasing composition. In
a particular embodiment, the solvent may comprise sodium silicate, a salt
and/or an
equivalent thereof. The concentration of the sodium silicate in the solvent
may vary
to correspond to the conditions of the oil reservoir. An oil reservoir may
contain
liquids such as water or brine, which may dilute the solvent. As such, in
these
instances, a solvent comprising a higher concentration of sodium silicate may
be
advantageous. The exact concentration of sodium silicate in the solvent may
depend on the anticipated amount of liquid that already exists in the oil
reservoir. In
one embodiment, the concentration of sodium silicate may be a concentration
that
will bring the concentration of sodium silicate in the liquid in the reservoir
to about
1%(by weight) when the solvent comes in contact with the liquid in the
reservoir. In
one embodiment, the concentration of sodium silicate may be a concentration
that
will bring the concentration of sodium silicate in the liquid in the reservoir
to less than
2% when the solvent comes in contact with the liquid in the reservoir. In
another
embodiment, the concentration of sodium silicate may be a concentration that
will
bring the concentration of sodium silicate in the liquid in the reservoir to
about 10%
when the solvent comes in contact with the liquid in the reservoir. In other
embodiments, the concentration of sodium silicate may be a concentration that
will
bring the concentration of sodium silicate in the liquid in the reservoir to
about 2%,
3%, 4%, 5%, 6%, 7%, 8% or 9% when the solvent comes in contact with the liquid
in
the reservoir. One of skill in the art will be able to determine the
appropriate
concentration to use without undue experimentation. In one embodiment, a
solvent
with a high concentration of sodium silicate (e.g., a concentration of greater
than
about 60% by weight) may be injected. In another embodiment, the concentration
of
sodium silicate may be between about 60% and 70% by weight. In another
embodiment, the concentration of sodium silicate may be between about 70% and
80% by weight. In another embodiment, the concentration of sodium silicate may
be
between about 80% and 90% by weight. In another embodiment, the concentration
of sodium silicate may be between about 90% and 99% by weight. In another
embodiment, the solvent may comprise a lower concentration of sodium silicate
(e.g., a concentration of less than 5%, 4%, 3%, 2% or 1% by weight).
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In another particular embodiment, the solvent may further comprise soy flour,
lignin flour and/or citrus pectin. In another embodiment, the solvent may be a
degreasing composition or a dispersion solution described in U.S. Patent No.
5,306,351, hereby incorporated by reference in its entirety as though fully
set forth.
While not wishing to be bound by any particular theory, the inventors believe
that the
solvent comprising sodium silicate causes the hydrocarbon to become fluid and
retards self adhesion, which reduces the viscosity of the oil and allows it to
move
more easily.
In another embodiment, the method may further comprise the use of gas
injection to extract the oil. Thus, the method may comprise providing a
solvent and a
quantity of gas; injecting the solvent into an oil reservoir; injecting the
quantity of gas
into the oil reservoir; and extracting the oil from the oil reservoir.
Extracting the oil
from the oil reservoir may be made by any known technology in the art; for
example,
by utilizing lifting technologies (e.g., pumps). The injection of the solvent
and the gas
may be performed in any order and may be performed simultaneously or
concurrently.
In one embodiment, the gas may be a gas capable of expanding in an oil
reservoir to push oil into a wellbore. In another embodiment, the gas may be a
gas
capable of dissolving in the oil to lower its viscosity and improve its flow
rate. These
gases may be natural gas, nitrogen, carbon dioxide (C02), or combinations
thereof.
One of skill in the art will recognize other gases capable of expanding in an
oil
reservoir and/or capable of dissolving in oil, and which may be appropriate to
use for
oil extraction. These gases may be from a naturally occurring reservoir,
produced
from industrial applications (e.g., natural gas processing, fertilizer,
ethanol, and
hydrogen plants), or produced specifically for use in oil extraction.
In another embodiment, the method may comprise the use of heat to extract
the oil. The introduction of heat may serve to lower the viscosity of the oil
and may
improve its ability to flow_ Heat may be introduced by any method known in the
art.
In one embodiment, heat may be introduced by heating the solvent prior to
injecting the solvent into the oil reservoir. Thus, the method may comprise
providing
a solvent; heating the solvent; injecting the heated solvent into the oil
reservoir; and
extracting the oil from the oil reservoir.
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In another embodiment, the heat may be introduced by injecting steam into
the oil reservoir. Thus, the method may comprise providing a solvent;
injecting the
solvent into the oil reservoir; injecting the steam into an oil reservoir; and
extracting
the oil from the oil reservoir.
The method may also further comprise the use of heat and injecting a quantity
of gas into the oil reservoir. Thus, the method may comprise providing a
solvent and
a gas; heating the solvent; injecting the heated solvent into the oil
reservoir; injecting
the gas into the oil reservoir; and extracting the oil from the oil reservoir.
Alternatively, the method may comprise providing a solvent and a gas;
injecting the
solvent into the oil reservoir; injecting the steam into an oil reservoir; and
extracting
the oil from the oil reservoir. The injection of the solvent, steam and/or gas
may be
performed in any order and may be performed simultaneously or concurrently.
In another embodiment, the method may further comprise the use detergent-
like surfactants to lower the surface tension. The surfactants may be added to
the
solvent. Surface tension may prevent oil droplets from moving through a
reservoir
and thus lowering the surface tension may assist the flow of the oil through a
reservoir.
Extraction of Oil from Oil Sands and Oil Shale
Particular embodiments of the present invention provides for the extraction of
oil from oil sands and oil shale. (See figure 1.) The oils sands or oil shale
may exist
in a variety of sizes. In one particular embodiment the oil is bitumen.
Oil Sands/Oil Shale Mining
In one embodiment of the present invention the oil sands or oil shale are
mined from the terrain. In a particular embodiment hydraulic and/or electric
shovels
and/or hydraulic excavators may be used to remove the oil sands or oil shale
from
the mining pit. In instances where the oil sands or oil shale are larger than
about two
inch in diameter, the removed oil sands or oil shale may be placed in a
crusher
where its size is reduced. The pieces may be further reduced to about two inch
pieces by use of rotary breakers. Hot or warm water may be added to create a
slurry. In one embodiment, a solvent may be used in addition to or in place of
the
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water. In one embodiment, the solvent may comprise a degreasing composition.
In
a particular embodiment, the solvent may comprise sodium silicate. In another
particular embodiment, the solvent may further comprise soy flour, lignin
flour and/or
citrus pectin. In another embodiment, the solvent may be a degreasing
composition
or a dispersion solution described in U.S. Patent No. 5,306,351. (See figure
2.) The
slurry may be further processed at an on-site extraction plant, or it may be
transported to an off-site extraction plant. Transporting the slurry may be
performed
by any method; for example, through a pipeline or by vehicles to the
extraction plant.
In another embodiment of terrain mining, a solvent may be used to fluidize oil
sands or oil shale pits and the oil sands or oil shale may be pumped and
transported
to an extraction facility. In one embodiment, the solvent may comprise a
degreasing
composition. In a particular embodiment, the solvent may comprise sodium
silicate.
In another particular embodiment, the solvent may further comprise soy flour,
lignin
flour and/or citrus pectin. In another embodiment, the solvent may be a
degreasing
composition or a dispersion solution described in U.S. Patent No. 5,306,351.
In a
particular embodiment, the solvent may be injected at pressures of about 4000
to
about 8000 psi to fluidize the oil sands or oil shale. The use of higher or
lower
pressure or mixing may aid the separation of bitumen from the oil sands or oil
shale.
The resulting slurry may be vacuumed and transported to an oil extraction
facility; at
the oil extraction facility, the oil may be extracted by methods known in the
art or in
accordance with various embodiments of the present invention.
Additional embodiments provide for methods of sub-terrain mining of the oil
sands. In one embodiment, sub-terrain mining may be performed by drilling a
pair of
horizontal wells in the oil sands reservoir for use in extracting the oil
sands from the
reservoir.
In one embodiment of the present invention, a waterflood with a solvent is
utilized to extract the oil sands. The method comprises providing a solvent;
injecting
the solvent into an oil sands reservoir; and extracting the oil sands from the
oil sands
reservoir.
In one embodiment, the solvent may comprise a degreasing composition. In
a particular embodiment, the solvent may comprise sodium silicate. In another
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particular embodiment, the solvent may further comprise soy flour, lignin
flour and/or
citrus pectin. In another embodiment, the solvent may be a degreasing
composition
or a dispersion solution described in U.S. Patent No. 5,306,351.
In another embodiment, the method may further comprise the use of gas
injection to extract the oil sands. Thus, the method may comprise providing a
solvent and a quantity of gas; injecting the solvent into an oil sands
reservoir;
injecting the quantity of gas into the oil sands reservoir; and extracting the
oil sands
from the oil reservoir. The injection of the solvent and the gas may be
performed in
any order and may be performed simultaneously or concurrently.
In one embodiment, the gas may be a gas that is capable of expanding in an
oil sands reservoir to push oil sands to a wellbore. In another embodiment,
the gas
may be a gas that is capable of dissolving in the oil sands to lower its
viscosity and
improve its flow rate. These gases may be natural gas, nitrogen, carbon
dioxide
(C02), or combinations thereof. One of skill in the art will recognize other
types of
gases that are capable of expanding in an oil sand reservoir and/or capable of
dissolving in the oil sands, and which may be appropriate to use for oil sands
extraction. These gases may be from a naturally occurring reservoir, produced
from
industrial applications (e.g., natural gas processing, fertilizer, ethanol,
and hydrogen
plants), or produced specifically for use in oil extraction.
In another embodiment, the method may comprise the use of heat to extract
the oil sands. The introduction of heat may serve to lower the viscosity of
the oil
sands and may improve its ability to flow.
In one embodiment, heat may be introduced by heating the solvent prior to
injecting the solvent into the oil sands reservoir. Thus, the method may
comprise
providing a solvent; heating the solvent; injecting the heated solvent into
the oil
sands reservoir; and extracting the oil sands from the oil sands reservoir.
In another embodiment, the heat may be introduced by injecting steam into
the oil sands reservoir. Thus, the method may comprise providing a solvent;
injecting the solvent into the oil sands reservoir; injecting the steam into
an oil sands
reservoir; and extracting the oil sands from the oil sands reservoir.
The method may also further comprise the use of heat and injecting a quantity
of gas into the oil sands reservoir. Thus, the method may comprise providing a
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solvent and a gas; heating the solvent; injecting the heated solvent into the
oil sands
reservoir; injecting the gas into the oil sands reservoir; and extracting the
oil sands
from the oil sands reservoir. Alternatively, the method may comprise providing
a
solvent and a gas; injecting the solvent into the oil sands reservoir;
injecting the
steam into an oil sands reservoir; and extracting the oil sands from the oil
sands
reservoir. The injection of the solvent, steam and/or gas may be performed in
any
order and may be performed simultaneously or concurrently.
In embodiments where the sub-terrain mining is performed by drilling a pair of
horizontal wells in the oil sands reservoir, steam may be injected into the
upper well
and the steam contacts the bitumen and heats the bitumen. The heated bitumen
(which may contain other materials, such as sand or clay) becomes mobile and
flows
with the condensed water from the steam to the lower horizontal well and flows
to
the surface or is pumped to the surface. The length of the wells may depend on
the
oil sands reservoir site. In various embodiments, the pair of wells may be
about 750
to about 1000 meters in length. The pair of wells may be drilled parallel to
one
another and spaced about 100 to about 200 meters apart.
In another embodiment, the method may further comprise the use detergent-
like surfactants to lower the surface tension. The surface tension may prevent
oil
droplets from moving through a reservoir and thus lowering the surface tension
may
assist the flow of the oil through a reservoir.
The bitumen in the bitumen mixture removed from the sub-terrain mines may
be extracted in accordance with various embodiments of the present invention.
Bitumen Extraction
During the oil extraction process, a quantity of bitumen is separated from the
rock, sand, clay and/or other materials. In various embodiments, the process
may
be performed at a high temperature to allow for extraction of the bitumen by
the
process of pyrolysis. In one embodiment, air may be added to the slurry and
transported to a gravity separation vessel. Due to the density differences,
the
bitumen will float atop and/or the bitumen will attach to the air bubbles and
rise to the
top to form a bitumen-rich froth. The inorganic contaminants, along with sand,
dirt,
silt, clay, etc., will settle to the bottom.
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In an alternative embodiment, the solvent may be used to separate the
bitumen from the rock, sand, clay and/or other materials. In one embodiment,
the
solvent may comprise a degreasing composition. In a particular embodiment, the
solvent may comprise sodium silicate. In another particular embodiment, the
solvent
may further comprise soy flour, lignin flour and/or citrus pectin. In another
embodiment, the solvent may be a degreasing composition or a dispersion
solution
described in U.S. Patent No. 5,306,351. In this alternative embodiment, the
addition
of air is optional for the separation process. Materials such as sand, dirt,
silt, clay,
etc. may have a greater affinity for the solvent thus may fall out of solution
and settle
to the bottom, and the bitumen will rise to the top. Furthermore, since the
bitumen
and the solvent may separate from each other, there may be a reduction or
elimination of the formation of froth. In instances where there are additional
organic
materials and/or contaminants, froth may still form. The materials that settle
at the
bottom are pumped to a tailing processing system. This settling action can be
enhanced with the use violent agitation before allowing it to settle. In an
alternative
embodiment, the solvent can be redrawn from the middle of a settling tank and
reused one or more times. (See figure 4.)
Water/Oil Separation
In embodiments where a froth (containing the bitumen) is formed, the froth
may be passed through a stripper, which removes the air bubbles and allows the
bitumen froth to be further processed. The bitumen froth may be placed through
a
counter-current decantation circuit. A solvent may be added to separate any
remaining solids and water. In one embodiment, the solvent may comprise a
degreasing composition. In a particular embodiment, the solvent may comprise
sodium silicate. In another particular embodiment, the solvent may further
comprise
soy flour, lignin flour and citrus pectin. In another embodiment, the solvent
may be a
degreasing composition or a dispersion solution described in U.S. Patent No.
5,306,351. This process may yield diluted bitumen that is at an appropriate
viscosity
to be transported by pipeline. (See figure 5.)
In an alternative embodiment, the bitumen mixture from the sub-terrain mining
may be subjected to this water/oil separation process. For example, the
bitumen
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mixture may be sent through a counter-current decantation circuit. A solvent
may be
added to separate any remaining solids and water. In a particular embodiment,
the
solvent may comprise sodium silicate. In another particular embodiment, the
solvent
may further comprise soy flour, lignin flour and/or citrus pectin. In another
embodiment, the solvent may be a degreasing composition or a dispersion
solution
described in U.S. Patent No. 5,306,351. This process may also yield diluted
bitumen
that is at an appropriate viscosity to be transported by pipeline.
The tailings from the crushing process may contain about 8% bitumen. A
solvent may be added to the tailings to extract additional bitumen. In a
particular
embodiment, the solvent may comprise sodium silicate. In another particular
embodiment, the solvent may further comprise soy flour, lignin flour and
citrus pectin.
In another embodiment, the solvent may be a degreasing composition or a
dispersion solution described in U.S. Patent No. 5,306,351. The resulting
mixture
can be processed through a high pressure mixer to assist in separating the
bitumen
from the sand. In a further embodiment, beneficial microbes may be added to
the
tailings for treatment or remediation of the tailings.
Another embodiment of the present invention utilizes a solvent as a diluent
for
the extracted bitumen. In a particular embodiment, the solvent may comprise
sodium silicate. In another particular embodiment, the solvent may further
comprise
soy flour, lignin flour and citrus pectin. In another embodiment, the solvent
may be a
degreasing composition or a dispersion solution described in U.S. Patent No.
5,306,351. The addition of the solvent may create a bitumen blend. The bitumen
blend may be at an appropriate viscosity to enable transportation of the
bitumen by
conventional pipelines.
Examples
The following examples are provided to better illustrate the claimed invention
and are not to be interpreted as limiting the scope of the invention. To the
extent
that specific materials are mentioned, it is merely for purposes of
illustration and is
not intended to limit the invention. One skilled in the art may develop
equivalent
means or reactants without the exercise of inventive capacity and without
departing
from the scope of the invention.
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Example I
This example illustrates the preparation of a dispersion solution which may be
utilized in various embodiments of the present invention. The manufacture of
the
dispersion solution occurs in three steps, first, five gallons of a natural
concentrate is
made, followed by the formation of a one hundred gallon completed concentrate,
and
then followed by the formation of an eighteen hundred gallon dispersion
solution.
First, a concentrated five gallon solution of soy flour, lignin flour and
citrus
pectin is prepared. Into a six gallon vessel, preferably having mechanical
mixing
capability, is first placed about four gallons of water. The additive
components which
will be used are as follows:
Soy flour (powdered) 1.0 pounds
Lignin flour (powdered) 0.5 pounds
Citrus Pectin 0.5 pounds
The one pound quantity of soy flour is added to the four gallon quantity of
water and mixed until smooth. Next, the one half pound of lignin flour is
slowly added
and mixed until the mixture is smooth. Next, the one half pound of citrus
pectin is
slowly added and mixed until the mixture is smooth. To the mixture is then
added
more water until the total liquid volume reaches five gallons. This mixture
will be
hereinafter referred to as the natural concentrate. The natural concentrate is
then
allowed to sit for 72 hours.
The soy flour may be commercially available from the A.E. Staley Company of
Decatur, Ill., 62525. The lignin flour may be commercially obtained from
Georgia
Pacific Corporation of Atlanta, Ga. The citrus pectin may be obtained from
Pectogel
of Great Neck, N.Y., 11021.
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The natural concentrate solution has the following composition:
Soy flour (powdered) 2.38%
Lignin flour (powdered) 1.19%
Citrus Pectin (powdered) 1.19%
Water 95.23%
100.0%
A silicate solution is formulated by first adding about forty gallons of water
to a
container (e.g., 125 gallon container). Next, fifty five gallons of sodium
silicate is
added to the forty gallons of water. The sodium silicate is commercially
available
under the trademarked name OXYCHEM, from Occidental Chemical Corporation,
Niagra Falls, N.Y. 14302. This sodium silicate is a liquid having a density of
about
11.67 pounds per gallon. The sodium silicate and water are mixed for about
three
minutes to form a sodium silicate-water mixture.
Next, the natural concentrate is added to the sodium silicate - water mixture,
and mixed for about seven minutes to form one hundred gallons of the completed
concentrate.
The completed concentrate has a composition by weight which is as follows:
Sodium Silicate (liquid) Na2O.XSiO2 62.951 %
Soy flour (powdered) 0.098%
Lignin flour (powdered) 0.049%
Citrus Pectin (powdered) 0.049%
Water 36.853%
100.0%
To the completed concentrate, 100 gallons, is added about 1700 gallons of
water to yield an eighteen hundred gallon dispersion solution, which is the
working
solution utilized in removing the oil.
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The completed dispersion solution has a composition by weight which is as
follows:
Sodium Silicate (liquid) Na20.XSiO2 4.1975%
Soy flour (powdered) 0.0065%
Lignin flour (powdered) 0.0032%
Citrus Pectin (powdered) 0.0032%
Water 95.7896%
100.0%
Example 2
As an option and for instances where the material to be removed is
particularly difficult, other materials may be added. One such material is
sodium
phosphate (powder) Na3PO4 which may be obtained from the Monsanto Chemical
Company of St. Louis, Mo. Another such material which may be added is soda
ash,
Na2CO3 obtainable commercially from Van Waters & Rogers of San Mateo, CA,
94403. Another material which may be added is a surfactant, also known as non-
ionic TRITON X100 which has a formula C33H6001o.5, and which is available from
Union Carbide of Danbury, Conn. Indeed other ingredients may be added to alter
the
performance of the dispersion solution.
Where needed, the sodium phosphate powder may be added in an amount of
about ten pounds dry weight per 1800 gallons of dispersion solution.
Similarly, the
soda ash may be added in an amount of about ten pounds dry weight per 1800
gallons of dispersion solution. The TRITON X100 may be added in an amount of
about one gallon of X100 per 1800 gallons of dispersion solution. In addition,
it is
permissible to add one, two, or all three of the above optional components per
single
1800 gallon dispersion solution batch.
While the description above refers to particular embodiments of the present
invention, it should be readily apparent to people of ordinary skill in the
art that a
number of modifications may be made without departing from the spirit thereof.
The
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accompanying claims are intended to cover such modifications as would fall
within
the true spirit and scope of the invention. The presently disclosed
embodiments are,
therefore, to be considered in all respects as illustrative and not
restrictive, the scope
of the invention being indicated by the appended claims rather than the
foregoing
description. All changes that come within the meaning of and range of
equivalency
of the claims are intended to be embraced therein.
is
