U.S. patent application number 14/856704 was filed with the patent office on 2016-04-28 for horizontal-flow oil sands separator for an aqueous extraction process.
The applicant listed for this patent is Edward J. Grave, Paul D. Oldenburg, Andrew P. STEINHAUSER. Invention is credited to Edward J. Grave, Paul D. Oldenburg, Andrew P. STEINHAUSER.
Application Number | 20160115390 14/856704 |
Document ID | / |
Family ID | 54325051 |
Filed Date | 2016-04-28 |
United States Patent
Application |
20160115390 |
Kind Code |
A1 |
STEINHAUSER; Andrew P. ; et
al. |
April 28, 2016 |
Horizontal-Flow Oil Sands Separator for an Aqueous Extraction
Process
Abstract
The disclosure includes techniques for recovering hydrocarbons
from a bituminous feed in an aqueous extraction process, comprising
a vessel that comprises a feed inlet on a proximate end of the
vessel, a feed outlet on a distal end of the vessel, a bitumen
outlet, and a plurality of hoppers, wherein each hopper comprises a
tailing outlet.
Inventors: |
STEINHAUSER; Andrew P.;
(Friendswood, TX) ; Grave; Edward J.; (Spring,
TX) ; Oldenburg; Paul D.; (Cypress, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
STEINHAUSER; Andrew P.
Grave; Edward J.
Oldenburg; Paul D. |
Friendswood
Spring
Cypress |
TX
TX
TX |
US
US
US |
|
|
Family ID: |
54325051 |
Appl. No.: |
14/856704 |
Filed: |
September 17, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62067280 |
Oct 22, 2014 |
|
|
|
Current U.S.
Class: |
208/391 ;
196/14.52; 208/390 |
Current CPC
Class: |
C10G 1/045 20130101;
C10G 1/047 20130101 |
International
Class: |
C10G 1/04 20060101
C10G001/04 |
Claims
1. A system for recovering hydrocarbons from a bituminous feed in
an aqueous extraction process, comprising: a vessel comprising: a
feed inlet on a proximate end of the vessel; a feed outlet on a
distal end of the vessel; a bitumen outlet; and a plurality of
hoppers, wherein each hopper comprises a tailing outlet.
2. The system of claim 1, wherein the vessel further comprises at
least one perforated baffle.
3. The system of claim 1, wherein at least one hopper is of a
different size or shape than another hopper.
4. The system of claim 1, wherein the vessel further comprises a
solvent injection inlet.
5. The system of claim 1, further comprising a second separator
operatively coupled to the feed outlet or a tailing outlet of a
hopper.
6. The system of claim 5, wherein the secondary separator is
operatively coupled to the tailing outlet of a hopper, wherein the
secondary separator comprises a plurality of secondary separator
vessels, and wherein each secondary separator vessel comprises at
least one secondary hopper.
7. A method for recovering hydrocarbons feed in an aqueous
extraction process, comprising: passing a bituminous feed through
an inlet of a vessel; passing the bituminous feed across a
plurality of hoppers disposed on a lower end of the vessel;
separating the bituminous feed into a stream comprising bitumen, a
stream comprising tailings, and a stream comprising middlings;
passing the stream comprising bitumen from the vessel; passing the
stream comprising tailings from the vessel; and passing the stream
comprising middlings through an outlet of the vessel.
8. The method of claim 7, further comprising adjusting the speed of
the bituminous feed flow based at least in part on the residence
time required to obtain a predetermined separation.
9. The method of claim 7, further comprising passing the tailings
to a secondary separator structure, wherein the secondary separator
structure comprises a second vessel having a second plurality of
hoppers.
10. The method of claim 9, further comprising injecting water or a
solvent into the secondary separator structure, the vessel, or
both.
11. The method of claim 9, wherein the secondary separator
structure comprises a plurality of second vessels each comprising
at least one hopper.
12. The method of claim 7, further comprising: passing the stream
comprising middlings to an inlet of a second vessel; passing the
stream comprising middlings across a second plurality of hoppers
disposed on a lower end of the second vessel; separating stream
comprising middlings to obtain additional bitumen, additional
tailings, and additional middlings; passing the additional bitumen
from the second vessel; passing the additional tailings from the
second vessel; and passing the additional middlings through an
outlet of the second vessel.
13. The method of claim 12, further comprising passing at least a
portion of the additional bitumen to the inlet of first vessel.
14. The method of claim 7, wherein passing the stream comprising
tailings from the vessel and passing the stream comprising
middlings through an outlet of the vessel occur via a unitary
outlet.
15. The method of claim 7, wherein the bituminous feed comprises a
bituminous froth.
16. The method according to claim 7, further comprising:
precipitating a portion of asphaltenes from the bituminous feed;
separating the stream comprising solvent, bitumen, asphaltenes, and
tailings into: a solvent containing bitumen stream, and a tailings
stream containing asphaltenes.
17. The method of claim 7, wherein the bituminous feed comprises a
solvent-extracted bitumen, further comprising: passing the stream
comprising bitumen to a solvent recovery unit; and separating the
stream comprising bitumen into a stream comprising a
solvent-extracted bitumen and a stream comprising solvent.
18. The method of claim 7, wherein separating the bituminous feed
occurs substantially in a mine, further comprising transporting at
least a portion of the stream comprising bitumen to a
geographically remote location.
19. A system for separating a bituminous feed in an aqueous
extraction process, comprising: a vessel; an inlet device coupled
to a vessel and configured to receive the bituminous feed; an
outlet device coupled the vessel and configured to discharge a
middlings feed; a plurality of bitumen outlets disposed on the
vessel; a plurality of hoppers disposed on a lower end of the
vessel, wherein each hopper comprises a tailing outlet; and a
secondary extraction vessel operatively coupled to the outlet
device so as to pass bitumen extracted in the secondary extraction
vessel to the inlet device in a counter-current extraction.
20. The system of claim 19, further comprising a secondary
separator structure, wherein the secondary separator structure
comprises a plurality of vessels having a second plurality of
hoppers, wherein the secondary separator structure comprises an
injection inlet for injecting water or a solvent, and wherein the
injection inlet is coupled to an injection header extending to at
least two of the plurality of vessels.
21. The system of claim 19, further comprising a solvent recovery
unit operatively coupled to at least one bitumen outlet.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority benefit of U.S.
Provisional Patent Application No. 62/067,280 filed Oct. 22, 2014
entitled HORIZONTAL-FLOW OIL SANDS SEPARATOR FOR AN AQUEOUS
EXTRACTION PROCESS, the entirety of which is incorporated
herein.
BACKGROUND
[0002] This section is intended to introduce various aspects of the
art, which may be associated with the present disclosure. This
discussion is believed to assist in providing a framework to
facilitate a better understanding of particular aspects of the
present disclosure. Accordingly, it should be understood that this
section should be read in this light, and not necessarily as
admissions of prior art.
[0003] Oil sands are sand deposits which in addition to sand
comprise clays, connate-water and bitumen. Depending on the depth
of the deposit, bitumen may be recovered by mining or in situ
thermal methods. Oil sand ore in a mining and extraction operation
is typically processed using mechanical means and chemicals
addition to separate the bitumen from the sands. Recovering the
highly viscous bitumen from the oil sand poses numerous challenges,
particularly since large quantities of heat and water are required
to extract the bitumen. Further, most oil sand deposits are located
in remote areas (such as, for example, in northeastern Alberta,
Canada), which can contribute to increased costs for transportation
and processing, especially in harsh weather conditions. Because of
these challenges, obtaining a good yield of bitumen product from
the oil sands is desired in order to reduce costs and waste.
[0004] In conventional gravity separators, a slurry stream
comprising liquid and solid particles is delivered to a vessel
where the solid particles settle by gravity and are passed or
removed from the bottom of the vessel, while the clarified liquid
is passed or removed from the top of the vessel. In most processes,
the solid particles are distributed in size, where the large
particles settle more quickly and the small particles settle more
slowly. Particles that have settling velocities smaller than the
upward flux (superficial velocity) of the liquid may not settle at
all, but may instead be carried over with the clarified liquid.
Conventional separators generally achieve their optimum separation
efficiency by having a uniform upward velocity distribution as this
determines the theoretical limit of the maximum particle size that
can be carried over. Increasing the vessel size, for example,
decreases the upward velocity and thereby reduces the size of the
largest particles that carry-over, thereby increasing the fraction
of particles that report to the underflow.
[0005] To achieve the separation described above in an aqueous
extraction process, conventional practice is to utilize a
comparatively large diameter, vertical-flow separator with multiple
inlet nozzles and a conical bottom to separate the solvated
bitumen/water/solid stream. Depending on the particular aqueous
extraction process, there may be one or multiple separators used in
parallel and/or series. The separators may use flow conditioning
devices in the inlets or within the body of the separator itself.
Owing to their comparatively large size and the remoteness of
typical oil sands sites, these separators are often
difficult/expensive to manufacture and transport to site.
[0006] Consequently, a need exists for an efficient oil sands
separator in an aqueous extraction process that reduces the space
requirements at the site. Further, a need exists for an efficient
oil sands separator for an aqueous extraction process that reduces
the difficulties and/or expenses associated with manufacture and/or
transportation to remote sites.
[0007] Bitumen product cleaning generally refers to another stage
within the oil sands process wherein solid separation is required.
In a bitumen product cleaning process, bitumen extracted from the
ore yet still containing varying amounts of water and solids is
subjected to a deasphalting process, which forms asphaltene-rich
aggregates that can be removed with residual solids and water via
gravity settling. Conventional gravity settling may generally refer
to techniques for separating a feed containing immiscible phases of
different densities, e.g., settling of a feed in a vessel to obtain
a heavier phase zone in the vicinity of the base and a lighter
phase zone above an interface with the heavier phase zone. Patent
publication number US2012-0145653, titled "Apparatus and Method for
Separating a Feed Material Containing Immiscible Phases of
Different Densities," contains a representative gravity settling
approach.
SUMMARY
[0008] One embodiment includes a system for recovering hydrocarbons
from a bituminous feed in an aqueous extraction process, comprising
a vessel that comprises a feed inlet on a proximate end of the
vessel, a feed outlet on a distal end of the vessel, a bitumen
outlet, and a plurality of hoppers, wherein each hopper comprises a
tailing outlet.
[0009] Another embodiment includes a method for recovering
hydrocarbons in an aqueous extraction process, comprising passing a
bituminous feed through an inlet of a vessel, passing the
bituminous feed across a plurality of hoppers disposed on a lower
end of the vessel, separating the bituminous feed into a stream
comprising bitumen, a stream comprising tailings, and a stream
comprising middlings, passing the stream comprising bitumen from
the vessel, passing the stream comprising tailings from the vessel,
and passing the stream comprising middlings through an outlet of
the vessel.
[0010] Still another embodiment includes a system for separating a
bituminous feed in an aqueous extraction process, comprising a
vessel, an inlet device coupled to a vessel and configured to
receive the bituminous feed, an outlet device coupled the vessel
and configured to discharge a middlings feed, a plurality of
bitumen outlets disposed on the vessel, a plurality of hoppers
disposed on a lower end of the vessel, wherein each hopper
comprises a tailing outlet; and a secondary extraction vessel
operatively coupled to the outlet device so as to pass bitumen
extracted in the secondary extraction vessel to the inlet device in
a counter-current extraction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The advantages of the present techniques are better
understood by referring to the following detailed description and
the attached drawings, in which:
[0012] FIG. 1 is a schematic diagram of a separator system for
separating a bituminous feed in an aqueous extraction process.
[0013] FIG. 2 is a cross section of a horizontal-flow separator
system for recovering hydrocarbons from a bituminous feed in an
aqueous extraction process.
[0014] FIG. 3A is an inlet side view cross sectional diagram of a
system for recovering hydrocarbons from a bituminous feed in an
aqueous extraction process.
[0015] FIG. 3B is a perspective view of the system for recovering
hydrocarbons from a bituminous feed in an aqueous extraction
process.
[0016] FIG. 4 is a block diagram describing a process for
recovering hydrocarbons from a bituminous feed in an aqueous
extraction process.
[0017] FIG. 5 is a block diagram describing a continued process for
recovering hydrocarbons from a bituminous feed in an aqueous
extraction process.
[0018] FIG. 6A is an embodiment of system for recovering
hydrocarbons from a bituminous feed in an aqueous extraction
process.
[0019] FIG. 6B is another embodiment of system for recovering
hydrocarbons from a bituminous feed in an aqueous extraction
process.
DETAILED DESCRIPTION
[0020] In the following detailed description section, specific
embodiments of the present techniques are described. However, to
the extent that the following description is specific to a
particular embodiment or a particular use of the present
techniques, this is intended to be for exemplary purposes only and
simply provides a description of the exemplary embodiments.
Accordingly, the techniques are not limited to the specific
embodiments described herein, but rather, include all alternatives,
modifications, and equivalents falling within the true spirit and
scope of the appended claims.
[0021] Disclosed herein is a horizontal-flow separator for
separating bitumen/water/solids stream(s) in oil sands operations.
Many configurations are possible, some including small diameter
fingers to accomplish polishing of the solvent/bitumen prior to
further processing and commercialization. For example, the primary
separator vessel may be the first stage separator in a process,
with the smaller fingers serving as the second stage separator.
Alternately, both stages could simultaneously accomplish one step
of separation in the overall process. Some embodiments place feeds
or draws between these two parts of a separation system. Conical
section(s) in the first and/or second stage separators may have
different base angles and/or sizes depending on the various
physical properties and/or characteristics of the liquids and
solids being processed.
[0022] Horizontal-flow separators may be inherently better at
remove smaller particles often found in oil sands tailings.
Additionally, horizontal-flow separators may allow designers an
additional degree of freedom in sizing the separator(s). Owing to
Stokes' Law, vertical-flow separators depend on the upflow velocity
to determine the theoretical particle cut-size obtainable with the
separator. Both diameter (superficial fluid velocity) and length
(residence time) can be adjusted for horizontal-flow separators to
meet product stream specifications based upon Stokes' Law settling.
However, disclosed horizontal-flow designs allow designers
additional degrees-of-freedom in configuring the separator(s). As
the disclosed separators include generally smaller diameter vessels
(or even pipe size fingers), it is likely to facilitate manufacture
and transport to remote sites, resulting in capital savings over
the current separator technology. Labor costs to erect the
separator should also be reduced in view of the above.
[0023] At the outset, for ease of reference, certain terms used in
this application and their meanings as used in this context are set
forth. To the extent a term used herein is not defined herein, it
should be given the broadest definition persons in the pertinent
art have given that term as reflected in at least one printed
publication or issued patent. Further, the present techniques are
not limited by the usage of the terms shown herein, as all
equivalents, synonyms, new developments, and terms or techniques
that serve the same or a similar purpose are considered to be
within the scope of the present claims.
[0024] As used herein, the term "bitumen" is a naturally occurring
heavy oil material. Generally, it is the hydrocarbon component
found in oil sands. Bitumen can vary in composition depending upon
the degree of loss of more volatile components. It can vary from a
very viscous, tar-like, semi-solid material to solid forms. The
hydrocarbon types found in bitumen can include aliphatics,
aromatics, resins, and asphaltenes. A typical bitumen might be
composed of:
[0025] 19 weight (wt.) % aliphatics (which can range from 5 wt.
%-30 wt. %, or higher);
[0026] 19 wt. % asphaltenes (which can range from 5 wt. %-30 wt. %,
or higher);
[0027] 30 wt. % aromatics (which can range from 15 wt. %-50 wt. %,
or higher);
[0028] 32 wt. % resins (which can range from 15 wt. %-50 wt. %, or
higher); and
[0029] some amount of sulfur (which can range in excess of 7 wt.
%).
In addition, bitumen can contain some water and nitrogen compounds
ranging from less than 0.4 wt. % to in excess of 0.7 wt. %. The
percentage of the hydrocarbon found in bitumen can vary. The term
"heavy oil" includes bitumen as well as lighter materials that may
be found in a sand or carbonate reservoir.
[0030] As used herein, the term "bituminous feed" refers to a
stream derived via an aqueous extraction process from oil sands
that requires downstream processing in order to realize valuable
bitumen products or fractions. The bituminous feed is one that
comprises bitumen along with undesirable components. Such a
bituminous feed may be derived directly from oil sands, and may be,
for example, raw oil sands ore. Further, the bituminous feed may be
a feed that has already realized some initial processing, e.g.,
aqueous extraction processing, but nevertheless requires further
processing. Also, recycled streams that comprise bitumen in
combination with other components for removal as described herein
can be included in the bituminous feed. A bituminous feed need not
be derived directly from oil sands, but may arise from other
processes. For example, a waste product from other extraction
processes which comprises bitumen that would otherwise not have
been recovered, may be used as a bituminous feed. Such a bituminous
feed may be also derived directly from oil shale oil, bearing
diatomite or oil saturated sandstones.
[0031] As used herein, the term "bituminous froth" refers to a
stream comprising substantially more bitumen than middlings or
tailings following separation or processing of the bituminous feed.
A representative composition of a bituminous froth may include
about 60 percent by weight (%/wt) bitumen, about 30%/wt water, and
about 10%/wt solids, such as fine or coarse particulate. As will be
understood by those of skill in the art, this composition may vary
significantly depending on, inter alia, the composition of the
bituminous feed.
[0032] As used herein, the phrase "fine particles" means those
solids having a size of less than 44 microns (.mu.m), that is,
material that passes through a 325 mesh (44 micron). The
aforementioned range includes any number within the range.
[0033] As used herein, the phrase "coarse particles" means those
solids having a size of greater than 44 microns (.mu.m). The
aforementioned range includes any number within the range.
[0034] As used herein, the phrase "Heavy oil" includes oils which
are classified by the American Petroleum Institute ("API"), as
heavy oils, extra heavy oils, or bitumens. The term "heavy oil"
includes bitumen. Heavy oil may have a viscosity of about 1,000
centipoise (cP) or more, 10,000 cP or more, 100,000 cP or more, or
1,000,000 cP or more. In general, a heavy oil has an API gravity
between 22.3.degree. API (density of 920 kilograms per meter cubed
(kg/m.sup.3) or 0.920 grams per centimeter cubed (g/cm.sup.3)) and
10.0.degree. API (density of 1,000 kg/m.sup.3 or 1 g/cm.sup.3). An
extra heavy oil, in general, has an API gravity of less than
10.0.degree. API (density greater than 1,000 kg/m.sup.3 or 1
g/cm.sup.3). For example, a source of heavy oil includes oil sand
or bituminous sand, which is a combination of clay, sand, water and
bitumen. The recovery of heavy oils is based on the viscosity
decrease of fluids with increasing temperature or solvent
concentration. Once the viscosity is reduced, the mobilization of
fluid by steam, hot water flooding, or gravity is possible. The
reduced viscosity makes the drainage quicker and therefore directly
contributes to the recovery rate.
[0035] As used herein, the term "hopper" means a container with a
narrow opening at bottom. This definition is intended to encompass
frustum-shaped hoppers, e.g., pyramidal frustum, conical frustum,
square frustum, pentagonal frustum, etc., as well as various
prismatoids and other slant geometries that may be suitably be
employed by those of skill in the art to practice the techniques
described herein.
[0036] As used herein, the term "hydrocarbon" means an organic
compound that primarily includes the elements of hydrogen and
carbon, although nitrogen, sulfur, oxygen, metals, or any number of
other elements may be present in small amounts. Hydrocarbons
generally refer to components found in heavy oil or in oil sands.
However, the techniques described are not limited to heavy oils but
may also be used with any number of other reservoirs to improve
gravity drainage of liquids. Hydrocarbon compounds may be aliphatic
or aromatic, and may be straight chained, branched, or partially or
fully cyclic.
[0037] As used herein, the term "middlings" means a stream
containing a watery suspension of bitumen and dispersed solids,
e.g., fine particles, coarse particles, etc., that remains after a
bituminous feed has been separated into a stream of substantially
bitumen or bitumen froth and a stream of substantially
tailings.
[0038] As used herein, the term "tailings" means an underflow
material remaining suspended in a mixture after bitumen and/or
middlings are separated from an oil sands or a bituminous feed.
Tailings generally comprise the refuse material comprising fine
and/or coarse particles of sand and/or clay, traces of bitumen,
etc. remaining after the bitumen or bitumen froth has been
extracted from the bituminous feed.
[0039] As used herein, the phrases "solvent-based recovery process"
or "solvent extraction process" include any type of hydrocarbon
recovery process that uses a solvent, at least in part, to enhance
the recovery, for example, by diluting or lowering a viscosity of
the hydrocarbon. Solvent-based recovery processes may be used in
combination with other recovery processes, such as, for example,
thermal recovery processes. In solvent-based recovery processes, a
solvent is injected into a subterranean reservoir. The solvent may
be heated or unheated prior to injection, may be a vapor or liquid
and may be injected with or without steam. Solvent-based recovery
processes may include, but are not limited to, solvent assisted
cyclic steam stimulation (SA-CSS), solvent assisted steam assisted
gravity drainage (SA-SAGD), solvent assisted steam flood (SA-SF),
vapor extraction process (VAPEX), heated vapor extraction process
(H-VAPEX), cyclic solvent process (CSP), heated cyclic solvent
process (H-CSP), solvent flooding, heated solvent flooding, liquid
extraction process, heated liquid extraction process, solvent-based
extraction recovery process (SEP), thermal solvent-based extraction
recovery processes (TSEP), and any other such recovery process
employing solvents either alone or in combination with steam. A
solvent-based recovery process may be a thermal recovery process if
the solvent is heated prior to injection into the subterranean
reservoir. The solvent-based recovery process may employ gravity
drainage.
[0040] As used herein, the terms "a" and "an," mean one or more
when applied to any feature in embodiments of the present
inventions described in the specification and claims.
[0041] The use of "a" and "an" does not limit the meaning to a
single feature unless such a limit is specifically stated.
[0042] As used herein, the term "about" means.+-.10% of the
subsequent number, unless otherwise stated.
[0043] As used herein, the terms "approximate," "approximately,"
"substantial," and "substantially," mean a relative amount of a
material or characteristic that is sufficient to provide the
intended effect. The exact degree of deviation allowable in some
cases may depend on the specific context. It should be understood
by those of skill in the art who review this disclosure that these
terms are intended to allow a description of certain features
described and claimed without restricting the scope of these
features to the precise numeral ranges provided. Accordingly, these
terms should be interpreted as indicating that insubstantial or
inconsequential modifications or alterations of the subject matter
described and are considered to be within the scope of the
disclosure.
[0044] As used herein, the definite article "the" preceding
singular or plural nouns or noun phrases denotes a particular
specified feature or particular specified features and may have a
singular or plural connotation depending upon the context in which
it is used.
[0045] FIG. 1 is a schematic diagram of a conventional separator
system 100 for separating a bituminous feed. The separator system
100 includes a deep cone settler 102 is depicted for receiving a
feed 104. The deep cone settler 102 permits settling of solids to
the lower region 106, while a low solids bitumen extract 108 can be
drawn off as overflow. A pump 110 is used to convey the overflow to
further cleaning or solvent removal in a solvent recovery unit. A
vent gas 112a and 112b is provided to and passed or removed from
the deep cone settler to provide a low oxygen environment within
the deep cone settler 102. One or more pumps 114 may be used to
pump the discharge 116 to a countercurrent washer 118 for disposal
and/or further processing.
[0046] FIG. 2 is a cross section of a horizontal-flow separator
system 200 for recovering hydrocarbons from a bituminous feed in an
aqueous extraction process. The system 200 includes a vessel 202
having a feed inlet 204 on a proximate end 206 of the vessel 202
and a feed outlet 208 on a distal end 210 of the vessel 202. The
vessel 202 also has a plurality of bitumen outlets 212 on an upper
end 214 of the vessel 202 and hoppers 216 having water and/or
tailing outlets 218 on a lower end 221 of the vessel 202. The
vessel 202 optionally houses a plurality of internal flow path
obstructions or baffles 220, e.g., perforated baffles, disposed
across the internal surface of the vessel 202. The bitumen outlets
212 optionally comprise outlet baffles 222, e.g., perforated
baffles. While shown at approximately the midline of the top of the
vessel 202, those of skill in the art will recognize that the
bitumen outlets 212 may alternately or additionally be located
elsewhere on the upper end 214 of the vessel 202, e.g., on or
towards the distal end 210, within the scope of this
disclosure.
[0047] Similarly, while shown at approximately the centerline of
the vessel 202, those of skill in the art will appreciate that a
plurality of suitable locations exist for placement of the feed
inlet 204 and the feed outlet 208, e.g., on the upper end 214, the
lower end 221, or a side, upper, or lower wall of the vessel 202 at
the proximate end 206 or distal end 210 of the vessel 202. Such
alternate placement may be based on a variety of considerations,
e.g., obtaining a desired flowpath into and/or out of the vessel
202, structural limitations external to the vessel 202, etc. The
vessel 202 may optionally include one or more injection inlets (not
depicted) for injecting water and/or solvent.
[0048] In operation, a bituminous feed, e.g., from a hydrotransport
pipeline transporting an aqueous oil sands slurry, may enter the
vessel 202 through the feed inlet 204. The feed may flow
horizontally across the vessel 202 and the hoppers 216 to the feed
outlet 208. As feed flows across the hoppers 216, the angle of the
wall(s) of each hopper 216 and the upflow (rise) created by feed
incidence against the wall(s) of each hopper 216 may cause
separation according to known particle settling principles, e.g.,
Stokes' Law settling. This process causes bitumen to float to the
top of the vessel 202 where it may be collected via bitumen outlets
212. In some embodiments, the size, shape, and/or narrowing angle
of the hopper (or incidence wall angle) of the hoppers 216 are
varied from one hopper 216 to another, e.g., to obtain bulk and
fine settling, to alter the rate of rise and/or settling, etc. In
some embodiments, separation may alternatively or be additionally
accomplished through horizontal flow settling as in traditional
3-phase separators. Hoppers 216 may function to collect high solid
component streams for ease of continuous removal (e.g., separation
may not necessarily be created by upflow caused by impedance
against hopper walls).
[0049] The velocity of the bituminous feed flow may be altered by a
variety of techniques known in the art, e.g., via pressurization,
preliminary feed treatment, additional pumps, etc., in order to
obtain certain desired separation characteristics within the vessel
202. Alternately or additionally, as described above, baffles 220
and/or 222 may be optionally added at various points to impede or
direct flow. Additionally, some embodiments may inject water and/or
solvent into the feed stream via an injection inlet disposed on the
vessel 202 in order to alter one or more characteristics of the
feed, e.g., viscosity, separation, frothing, disaggregation, etc.
As the feed separates, water and/or tailings, may pass through the
water and/or tailing outlets 218 as bitumen is collected through
the bitumen outlets 212. A feed stream comprising substantially
middlings and/or unseparated bituminous feed may continue through
the feed outlet 208. In some embodiments, at least a portion of the
discharge through the feed outlet 208 is recycled through the
vessel 202. In some embodiments, at least a portion of the
discharge through the feed outlet 208 is passed to a second vessel
202 to substantially repeat the process. Embodiments using the
vessel 202 in place of a Primary Separation Cell in a water-based
process may generate a middlings stream that is sent to a secondary
recovery system comprising a number of stirred vessels in series.
The underflow from secondary recovery becomes a tailings (waste)
stream. Such embodiments may feed the overflow back into the
Primary Separation Cell.
[0050] FIG. 3A is an inlet side view cross sectional diagram of a
system 300 for recovering hydrocarbons from a bituminous feed in an
aqueous extraction process. FIG. 3B is a perspective view of the
system 300 for recovering hydrocarbons from a bituminous feed in an
aqueous extraction process. The components of the system 300 may be
substantially the same as the corresponding components of FIG. 2
unless otherwise noted. The system 300 comprises a secondary
separator 302 commonly coupled to the tailing outlets 218. Some
embodiments may attach a secondary separator 302 to less than all
of the tailing outlets 218, and other embodiments may attach
separate secondary separators 302 to one or more of the tailing
outlets 218. The secondary separator 302 has a water and/or solvent
injection inlet 303 for injecting water and/or solvent. Those of
skill in the art will appreciate that in some embodiments the
solvent injection inlet 303 may optionally comprise a common
injection header spanning the length of a common secondary
separator 302 or a plurality of secondary separators 302 (in
suitable embodiments) for distributing the water and/or solvent.
The secondary separator 302 has a plurality of secondary vessels
304, also referred to herein as "fingers" 304, having a plurality
of secondary hoppers 306 with secondary water and/or tailings
outlets 308. While depicted with a plurality of secondary hoppers
306, alternate embodiments may have more, fewer, or even no
secondary hoppers 306. Further, different fingers 304 may have
differing numbers of secondary hoppers 306, and may include
differing sizes, shapes, and/or narrowing angles of any of the
secondary hoppers 306. The fingers 304 each have a hydrocarbon or
bitumen outlet 310 for passing hydrocarbons therethrough. Although
not depicted, those of skill in the art will appreciate that a
plurality of baffles may be optionally added in the secondary
separator 302 as described above with respect to the baffles 220
and/or 222 in the vessel 202.
[0051] In operation, the vessel 202 portion of the system 300 may
function as described above in connection with the system 200.
Namely, a bituminous feed may enter the vessel 202 through the feed
inlet 204. The feed may flow horizontally across the vessel 202 and
the hoppers 216 to the feed outlet 208. As feed flows across the
hoppers 216, the angle of the wall(s) of each hopper 216 and the
upflow (rise) created by feed incidence against the wall(s) of each
hopper 216 causes separation according to known particle settling
principles. This process causes bitumen to float to the top of the
vessel 202 where hydrocarbons may be collected via bitumen outlets
212. As the feed separates, a stream comprising substantially
middlings and/or unseparated bituminous feed may continue through
the feed outlet 208 as bitumen is collected through the bitumen
outlets 212. Water, tailings, and/or some amount of bituminous feed
(collectively, the "secondary bituminous feed") may pass through
the water and/or tailing outlets 218 and into the secondary
separator 302. Water and/or solvent may be injected into the
secondary separator 302 at the water and/or solvent injection inlet
303 in order to alter one or more characteristics of the secondary
bituminous feed, e.g., viscosity, separation, frothing,
disaggregation, etc. It will be noted that a variety of locations
are available for placing the injection inlet 303, including at
each water and/or tailings outlet 218, and such alternate
embodiments are within the scope of this disclosure. The secondary
bituminous feed may be passed through the fingers 304 for secondary
or second phase separation. Second phase separation in each of the
fingers 304 may occur in substantially the same the same way as the
initial or first phase separation in the vessel 202. Specifically,
as the secondary bituminous feed flows across the secondary hoppers
306, the angle of the wall(s) of each hopper 306 and the upflow
(rise) created by feed incidence against the wall(s) of each hopper
306 causes separation according to known particle settling
principles. This process causes hydrocarbons or bitumen to float to
the top of the fingers 304 where the hydrocarbons or bitumen may be
collected via bitumen outlets 310. The remainder of the secondary
bituminous feed, which may comprise substantially tailings, may be
discharged through the secondary water and/or tailings outlets 308.
Following discharge, the remaining secondary bituminous feed may be
recirculated and/or otherwise combined with the bituminous feed,
may be sent for further processing, may be collected and disposed
of as tailings, or may undergo another process as optionally
determined according to the skill of those in the art.
[0052] FIG. 4 is a block diagram describing a process 400 for
recovering hydrocarbons in an aqueous extraction process. At block
402, the process 400 may pass a bituminous feed through an inlet,
e.g., the feed inlet 204 of FIG. 2, of a vessel, e.g., the vessel
202 of FIG. 2. At block 404, the process 400 may flow the
bituminous feed across a plurality of hoppers, e.g., the hoppers
216 of FIG. 2, disposed on a lower end of the vessel. At block 406,
the process 400 may separate the bituminous feed to obtain bitumen
and tailings. Separating the bituminous feed may include flowing
the bituminous feed across the hoppers. In so doing, the angle of
the wall(s) of each hopper and the upflow (rise) created by feed
incidence against the wall(s) of each hopper may cause separation
according to known particle settling principles, e.g., Stokes' Law
settling. At block 408, the process 400 may remove the hydrocarbons
and/or bitumen from the vessel, e.g., via bitumen outlets 212. At
block 410, the process 400 may pass or remove at least a portion of
the tailings created from the separation process from the vessel.
For example, the tailings may be discharged through one or more
water and/or tailing outlets, e.g., the water and/or tailing
outlets 218 of FIG. 2. At block 412, the process 400 may pass at
least a portion of the bituminous feed and/or a stream comprising
middlings through an outlet, e.g., the feed outlet 208 of FIG. 2,
of the vessel.
[0053] FIG. 5 is a block diagram describing a continued process 500
for recovering hydrocarbons in an aqueous extraction process. The
process 500 may comprise the process 400 and may begin after block
412 of FIG. 4. At block 502, the at least a portion of the
bituminous feed, or secondary bituminous feed, is passed to a
secondary separator, e.g., the secondary separator 302 of FIG. 3.
At block 504, the secondary bituminous feed is fed to at least one
secondary separator finger, e.g., a finger 304 of FIG. 3. At block
506, each finger may separate the secondary bituminous feed. For
example, each finger may comprise at least one hopper, e.g., a
secondary hopper 306 of FIG. 3, and may flow the secondary
bituminous feed across the hopper to obtain a desired settling of
the secondary bituminous feed. At block 508, hydrocarbons or
bitumen may be collected through one or more finger outlets, e.g.,
a bitumen outlet 310, and the remainder of the secondary bituminous
feed, which may comprise substantially tailings, may be discharged
through one or more outlets, e.g., water and/or tailings outlets
308 of FIG. 3.
[0054] FIG. 6A is an embodiment of an aqueous extraction process
600 for recovering hydrocarbons from a bituminous feed in an
aqueous extraction process comprising a system 300. The system 300
may be substantially the same as the system 300 of FIG. 3 unless
otherwise noted. In the aqueous extraction process 600, the system
300 replaces a conventional primary separation vessel, e.g., the
deep cone settler 102 of FIG. 1. The aqueous extraction process 600
further includes a secondary extraction 602 for performing
conventional oil sands separation following initial separation in
the system 300. As illustrated, a bituminous feed may be passed to
the system 300 via line 604 and processed, e.g., according to the
process 400 of FIG. 4, to create a stream comprising bitumen froth
passed via line 606, a stream comprising tailings passed via line
608, and a stream comprising middlings passed via line 610.
Following processing in the system 300, a stream comprising
middlings may be passed to the secondary extraction 602 where the
middlings are further processed to create an output stream
comprising flotation tailings via line 614 and an output stream
comprising bitumen via line 616. Line 616 is depicted in a
countercurrent configuration, returning a stream comprising bitumen
froth to the input of the system 300.
[0055] In some embodiments, e.g., embodiments wherein the process
600 is placed in the context of lean froth production (LFP), the
process 600 occurs substantially within a mine, e.g., to allow for
reduced tailings transport for in-pit tailings disposal. In such
embodiments, the process 600 may serve to perform an initial
bitumen separation from sand and clay prior to transport, e.g.,
transporting substantially oil sand froth, and secondary processing
at a geographically remote location, e.g., a central plant.
[0056] FIG. 6B is an embodiment of an aqueous extraction process
650 for recovering hydrocarbons from a bituminous feed. The system
650 may replace a conventional froth settling unit within a
Paraffin Froth Treatment (PFT) process. A PFT is a process known by
those of skill in the art for separating water, solids, and
asphaltenes from a solvent-diluted bitumen feed. The aqueous
extraction process 650 depicts a counter-current extraction and,
consequently, the process 650 comprises two separator systems 652a
and 652b, e.g., each a system 300 of FIG. 3, modified as noted
herein. It will be appreciated that the systems 652a and 652b each
comprise a unitary outlet for middlings and/or tailings, e.g.,
lines 654a and 654b, respectively. The output stream comprising
middlings and/or tailings passed via line 654a is passed to the
system 652b, e.g., serving as the input bituminous feed into the
system 652b, while the output stream comprising middlings and/or
tailings passed via line 654b is passed to a tailings solvent
recovery unit 658. The tailings solvent recovery unit 658 separates
the received stream into a stream comprising froth treatment
tailings, passed via line 660, and a stream comprising solvent,
which may join with the middlings and/or tailings line 654a via
line 662. The systems 652a and 652b each comprise outlets for
passing bitumen separated in the systems 652a and 652b, lines 656a
and 656b, respectively. Bitumen and/or bitumen froth passed via
line 656a is carried to a solvent recovery unit 664, which
separates the received feed into a stream comprising bitumen,
passed via line 666, and a stream comprising solvent, which may
join with the solvent recovery unit return line 662 via line 668.
At least a portion of the bitumen and/or bitumen froth passed via
line 656a may be returned to the inlet of the system 652a via line
656c.
[0057] While the present techniques may be susceptible to various
modifications and alternative forms, the exemplary embodiments
discussed herein have been shown only by way of example. However,
it should again be understood that the techniques disclosed herein
are not intended to be limited to the particular embodiments
disclosed. Indeed, the present techniques include all alternatives,
modifications, combinations, permutations, and equivalents falling
within the scope of the disclosure and appended claims.
* * * * *