Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
SYSTEM AND PROCESS FOR RECOVERING HYDROCARBONS USING
SUPERCRITICAL FLUID
[0001] CROSS-REFERENCE TO RELATED APPLICATIONS
[00021
[0003] TECHNOLOGICAL FIELD
100041 The present disclosure relates to a process for recovering hydrocarbon
fluids and, in some
cases, partially upgrading and/or transporting the hydrocarbon fluids. More
particularly, the
present disclosure relates to a process for recovering, partial upgrading and
transporting
hydrocarbons using an aqueous fluid at supercritical conditions.
100051 BACKGROUND
[0006] Oil recovered, or produced, and transported from a significant number
of oil reserves
around the world is simply too heavy to flow under reservoir and ambient
conditions. This makes
it challenging to bring remote, heavy oil resources closer to the markets
where refining facilities
are accessible.
[0007] In order to render such heavy oils flowable in the reservoir and
production well(s), one
conventional method known in the art is to use two phase saturated steam
generation and
distribution. That method typically presents a challenge in achieving
sufficiently uniform
distribution of latent heat in the reservoir. Latent heat profile control
devices are known and used
in the industry to distribute vapor and liquid phases more evenly at the
perforations; however,
installation and retrieval this equipment can be increase the complexity and
cost of a hydrocarbon
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Date Recue/Date Received 2023-07-14
production operation, and the difficulty of installing and retrieving the
equipment can be further
increased in horizontal wells by the bend radius at the heel of the well and
the sand that can settle
to the bottom of the casing.
[0008] Once heavy oil is produced from a well, it is conventional practice in
the industry to
facilitate the transport of the heavy oil by heating it to a high temperature
and maintaining high
pressure in insulated shipping pipelines.
[0009] Also, in order to render such heavy oils flowable, one common method
known in the art is
to reduce the viscosity and density of the heavy oil by mixing the heavy oil
with a sufficient diluent.
The diluent may be naphtha, syncrude, or any other fluid stream that has a
sufficiently higher API
gravity (i.e., much lower density) than the heavy oil. Typically, this heavy
oil must be taken to an
upgrader either in the field or at some remote central location before
shipment to a refinery.
[0010] In one conventional heavy oil production operation, diluted crude oil
is sent from the
production wellhead via a pipeline to an upgrading facility. Two key
operations occur at the
upgrading facility: (1) the diluent stream is recovered and recycled back to
the production wellhead
in a separate pipeline, and (2) the heavy oil is upgraded with suitable
technology known in the art
(coking, hydrocracking, hydrotreating, or the like) to produce higher-value
products for market.
Some typical characteristics of these higher-value products include: lower
sulfur content, lower
metals content, lower total acid number (TAN), lower residuum content, higher
API gravity, and
lower viscosity. Most of these desirable characteristics are achieved by
reacting the heavy oil with
hydrogen gas at high temperatures and pressures in the presence of a catalyst.
Depending on the
location of the upgrading facility and other market factors, the upgraded
crude might be sent to the
end-users via tankers and/or additional pipelines.
[0011] These diluent addition/removal processes and hydrogen-addition or other
upgrading
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processes can be undesirable in some cases. For example, the infrastructure
required for the
handling, recovery, and recycling of diluent can be expensive, especially over
long distances, and
diluent may not be readily availability at a reasonable price. The hydrogen-
addition processes such
as hydrotreating or hydrocracking typically require significant investments in
capital and
infrastructure which add to the total cost of producing the heavy oil. The
hydrogen-addition
processes also typically have high operating costs, since hydrogen production
costs are highly
sensitive to natural gas prices. Some remote heavy oil reserves may not even
have access to
sufficient quantities of low-cost natural gas to support a hydrogen plant.
These hydrogen-addition
processes also generally require expensive catalysts and resource intensive
catalyst handling
techniques, including catalyst regeneration. In some cases, the refineries
and/or upgrading facilities
that are located closest to the production site may have neither the capacity
nor the facilities to
accept the heavy oil. Additionally, coking is often used at refineries or
upgrading facilities. Sulfur
is removed prior to the coking process, and significant amounts of by-product
solid coke are
produced during the coking process, leading to lower liquid hydrocarbon yield.
In addition, the
liquid products from a coking plant often need further hydrotreating. Further,
the volume of the
product from the coking process is significantly less than the volume of the
feed crude oil.
[0012] For these and other reasons, there exists a continued need for improved
systems and
processes for recovering hydrocarbon fluids, particularly heavy oils.
[0013] SUMMARY OF THE INVENTION
[0014] The present disclosure provides a system and process for recovering
hydrocarbons using a
supercritical fluid, such as supercritical water.
[0015] In one embodiment, the system for providing a first aqueous fluid, such
as drinking water,
treated wastewater, untreated wastewater, river water, lake water, seawater,
or produced water. The
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Date Recue/Date Received 2023-07-14
system also includes a heater for receiving the first aqueous fluid and
heating the first aqueous
fluid to a temperature from 374 C to 1000 C at a pressure from 3205 to 10000
psia, such that the
first aqueous fluid is in a supercritical phase (also referred to and
understood herein to be a
supercritical state), a delivery system configured to receive the first
aqueous fluid from the heater
and delivery the first aqueous fluid for injection into an underground
hydrocarbon reservoir in the
supercritical phase, and a well configured to recover from the reservoir
hydrocarbons that have
been heated by the first aqueous fluid. One or more venturi chokes can be
disposed in the reservoir,
e.g., in a horizontal portion of a well that extends through at least part of
the reservoir, and
configured to inject the supercritical, dense-phase fluid so that the first
aqueous fluid flashes across
the venturi choke(s) as it is injected.
[0016] In some cases, the system is configured to mix a second aqueous fluid
with the recovered
hydrocarbons at conditions sufficient to upgrade at least a portion of the
hydrocarbons. The system
can be configured to provide the second aqueous fluid in a supercritical
phase.
[0017] The present disclosure also provides a process for recovering
hydrocarbons, such as whole
heavy petroleum crude oil and tar sand bitumen. According to one embodiment,
the process
includes providing a first aqueous fluid in a supercritical phase at a
temperature from 374 C to
1000 C and a pressure from 3205 to 10000 psia to an underground hydrocarbon
reservoir. The first
aqueous fluid can be drinking water, treated wastewater, untreated wastewater,
river water, lake
water, seawater, produced water, or mixtures thereof. The first aqueous fluid
is injected into the
underground hydrocarbon reservoir to heat the hydrocarbons. The heated
hydrocarbons are
recovered from the reservoir. In some cases, the step of injecting the first
aqueous fluid includes
delivering the first aqueous fluid through a wall of a wellbore (e.g., through
a venturi choke
installed in the wall of the wellbore) to the hydrocarbon reservoir. For
example, the first aqueous
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fluid can flash across a venturi choke from a steam or fluid injector into the
underground
hydrocarbon reservoir, such as by flashing the first aqueous fluid to at least
70% steam quality.
[0018] In some embodiments, the process also includes mixing a second aqueous
fluid with the
recovered hydrocarbons at conditions sufficient to upgrade at least a portion
of the hydrocarbons.
The second aqueous fluid can be in the supercritical phase, and/or the mixing
of the fluids can
occur in a wellbore or production pipeline. The step of upgrading can include
reducing the viscosity
of at least a portion of the hydrocarbons. For example, the upgrade operation
can be characterized
by a reaction residence time from 8 minutes to 2 hours. The first aqueous
fluid and the second
aqueous fluid can be generated individually or in a single supercritical fluid
generation operation,
e.g., from a modified steam generator or modified heat recovery steam
generator. In some cases,
the first aqueous fluid and the second aqueous fluid are generated from a 50
millions BTU/HR
modified oilfield steam generator. One or more heat exchangers, e.g., achieved
in a wellbore or
pipeline or other similar equipment can be used to achieve heat exchange
between the second
aqueous stream and the recovered hydrocarbons before mixing.
[0019] In one embodiment the instant application pertains to a process for
recovering
hydrocarbons. The process comprises making a supercritical dense phase fluid
comprising water
suitable for heating hydrocarbons. The first supercritical dense phase fluid
is generated by heating
water to a supercritical dense phase at a temperature from 374 C to 1000 C and
a pressure from
3205 to 10000 psia at a surface location. The first supercritical phase fluid
is flashed to a range of
about 70% to 100% steam quality or superheated steam to heat the hydrocarbons
with the about
70% to 100% steam quality or superheated steam.
[0020] In another embodiment the application pertains to a system for
recovering hydrocarbons.
The system comprises a supercritical phase fluid comprising water heated to a
temperature from
Date Recue/Date Received 2023-07-14
374 C to 1000 C at a pressure from 3205 to 10000 psia. The system also
comprises a delivery
system configured to receive the supercritical phase fluid and deliver the
supercritical phase fluid
to hydrocarbons to heat the hydrocarbons to reduce viscosity of at least a
portion of the
hydrocarbons. The delivery system is configured such that the supercritical
phase fluid drops in
pressure and flashes to a range of about 70% to 100% steam quality or
superheated steam prior to
contacting the hydrocarbons. A well configured to recover the heated
hydrocarbons.
100211 In another embodiment the application pertains to a process for
recovering hydrocarbons,
comprising making a supercritical dense phase fluid comprising water suitable
for heating
hydrocarbons. The supercritical dense phase fluid is generated by heating
water to a supercritical
dense phase at a temperature from 374 C to 1000 C and a pressure from 3205 to
10000 psia. The
supercritical phase fluid is isentropically expanded to a range of about 70%
to 100% steam quality
or superheated steam to heat the hydrocarbons with the about 70% to 100% steam
quality or
superheated steam.
[0022] In another embodiment the application pertains to a system comprising a
distribution
piping system configured to receive a subcritical phase fluid, a supercritical
phase fluid, or any
combination thereof. The system comprises an isentropic expansion device
operably connected
to the distribution piping system. The isentropic expansion device is
configured to expand the
subcritical phase fluid, the supercritical phase fluid, or any combination
thereof to a range of from
about 70% to 100% steam quality or superheated steam prior to said 70% to 100%
steam quality
or superheated steam heating one or more hydrocarbons. A well is configured to
recover heated
hydrocarbons.
[0022a] In accordance with another aspect, there is a process for recovering
hydrocarbons,
comprising: making a supercritical dense phase fluid comprising water suitable
for heating
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hydrocarbons, wherein the supercritical dense phase fluid is generated by
heating water to a
supercritical dense phase at a temperature from 374 C to 1000 C and a pressure
from 3205 to
10000 psia at a surface location; and isentropically expanding the
supercritical phase fluids to a
range of about 70% to 100% steam quality or superheated steam to heat the
hydrocarbons with the
about 70% to 100% steam quality or superheated steam.
[0022b] In accordance with a further aspect, there is a system comprising: a
distribution
pipingsystem configured to receive a subcritical phase fluid, a supercritical
phase fluid, or any
combination thereof; an isentropic expansion device operably connected to the
distribution piping
system wherein the isentropic expansion device is configured to expand the
subcritical phase fluid,
the supercritical phase fluid, or any combination thereof to a range of from
about 70% to 100%
steam quality or superheated steam prior to said about 70% to 100% steam
quality or superheated
steam heating one or more hydrocarbons; and a well configured to recover
heated hydrocarbons.
[0023] DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a schematic illustration of a system according to one
embodiment of the present
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Date Recue/Date Received 2023-07-14
disclosure, showing a process for recovery and partial upgrading for
transportation of hydrocarbon
fluids;
[0025] FIG. 2 is a schematic illustration of a system according to another
embodiment of the
present disclosure, configured to omit an upgrading operation illustrated in
FIG. 1.
[0026] FIG. 3 is a simplified block diagram showing a fluid injection into a
hydrocarbon reservoir
in the absence of isentropic expansion.
[0027] FIG. 4 is a simplified block diagram showing a supercritical injection
into a hydrocarbon
reservoir using at least one subsurface isentropic expansion device.
[0028] FIG. 5 is a simplified block diagram showing a supercritical injection
into a hydrocarbon
reservoir using at least one isentropic expansion device at or near a boiler
outlet.
[0029] FIG. 6 is a simplified block diagram showing a supercritical injection
into a hydrocarbon
reservoir using at least one isentropic expansion device subsequent to any
distribution piping
system and/or prior to any injection system.
[0030] FIG. 7 is a diagram showing supercritical water (SCW) in relation to a
once through steam
generator (OTSG).
[0031] DETAILED DESCRIPTION
[0032] The present disclosure now will be described more fully hereinafter
with reference to the
accompanying drawings, in which some, but not all embodiments are shown.
Indeed, these
embodiments may be embodied in many different forms and should not be
construed as limited to
the embodiments set forth herein; rather, these embodiments are provided so
that this disclosure
will satisfy applicable legal requirements. Like numbers refer to like
elements throughout.
[0033] Embodiments describing the process of the present disclosure are
referenced in FIG. 1.
More specifically, the following embodiments describe a system 10 and
processes for
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Date Recue/Date Received 2023-07-14
implementing the present disclosure.
[0034] In the system 10 of FIG. 1, a stream of aqueous fluid, i.e., boiler
feed water 12, is input
from a source 52 into a water heater 14 for a heating operation. Examples of
the boiler feed water
include drinking water, treated wastewater, untreated wastewater, river water,
lake water, seawater,
produced water (such as from a hydrocarbon production operation) or mixtures
thereof, and it is
appreciated that the boiler feed water can include water with various
materials dissolved or
otherwise contained in it. The boiler feed water 12 is typically provided in a
liquid phase and in
the temperature range of about 0 C to 100 C.
[0035] Examples of the water heater 14 include oilfield-type steam generators
and gas
turbine/generator cogeneration heat recovery steam generators, modified to
heat the feed water 12
to supercritical conditions. In particular, the water heater 14 can be
modified with upgraded tubing
materials and schedules designed for high pressure in the range of about 3205
to 4060 psig and a
temperature in the range of about 374 C to 455 C and a capacity in the range
of about 50 to 150
millions btu/hr or higher. In one embodiment based on this design, the heating
operation performed
in the water heater 14 generates high pressure, dense phase fluid at a
temperature from 374 C to
1000 C and a pressure from 3205 to 10000 psia. At these conditions, the
aqueous fluid is
considered to be in a supercritical dense phase.
[0036] A stream of the supercritical dense phase fluid 16 resulting from the
heating operation is
output from the water heater 14 into a delivery system 18, such as high
pressure piping having a
diameter in the range of about 6 to 61 cm. Based on this design, supercritical
dense phase fluid can
be distributed for long distances, and there is typically no longer a need for
equal phase splitting
to maintain steam quality in the distribution system 18 as is typically
performed in conventional
sub-critical two-phase steam delivery systems. Although the requirements for
the pipe material
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Date Recue/Date Received 2023-07-14
strength and wall thickness of the pipes used in the delivery system 18 may be
relatively greater
than those used in conventional sub-critical delivery systems, the overall
cost of the system can be
substantially reduced due to the lower hoopstresses and cost of smaller
diameter piping. Also, as
long as the pressure is adequately maintained in the delivery system 18, there
is less potential for
transient water head impact and resulting vibrations ("steam hammer" effects)
that are experienced
in conventional delivery systems, and any vibrations and acoustics generated
by such steam
hammer effects would typically act on smaller piping surface areas with
smaller forces in the
present delivery system 18 as compared to the larger internal piping surfaces
and steam hammer
forces associated with conventional sub-critical delivery systems.
[0037] The stream 16 from the heater 14 is split into first and second streams
of aqueous fluids,
such as a reservoir feed stream 20 and a wellbore or pipeline feed stream 22
as shown in FIG. 1.
The feedrate split ratio (expressed as the mass flow rate of the reservoir
feed stream to the mass
flow rate of the pipeline feed stream) is typically in the range of about
1:0.5 to 1:2, typically
depending upon the maturity of the steamflood.
[0038] The reservoir feed stream 20 is injected into a subterranean reservoir
24 via one or more
venturi chokes 26 or other appropriate choking devices. The system 10 can be
used to deliver the
feed stream 20 to a variety of different types of reservoirs. In some
representative examples, the
reservoir 24 is a sandstone, diatomite, shale oil, or carbonate heavy
petroleum crude oil or tar sand
bitumen reservoirs.
[0039] The one or more venturi chokes 26 are typically installed in a well 28
that extends
subterraneously at least partially vertically and/or horizontally from the
ground surface 30, such as
in the horizontal portion of the well 28 illustrated in FIG. 1. In one
embodiment, the venturi choke
26 includes a hardened steel alloy or tungsten carbide coated venturi choke
projectile that can be
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Date Recue/Date Received 2023-07-14
installed with a perforating gun that perforates the steel and concrete casing
of the well after the
well is drilled and completed, typically by disposing a string of steel casing
or liner in the well and
surrounding the it with concrete. If the chokes 26 are installed in this
manner, it is not necessary to
use well bore equipment, such as wellbore latent heat profile control devices,
and this can simplify
the installation, particularly in horizontal wells where installing and
retrieving tubing and cup-
packer chokes can be difficult due to the heel bend (or other nonlinearities
along the length of the
well) and build-up of sand at the bottom of the casing.
[0040] As the reservoir feed stream 20 passes though the venturi choke(s) 26,
at least a portion of
the supercritical phase water flashes to higher quality steam at the reservoir
conditions. In one
embodiment, the supercrictical phase water flashes to a range of about 70 to
100% steam quality
or, superheated steam, across the venturi choke 26. Additionally, if there is
near wellbore damage
that reduces permeability in a particular area, the venturi choke 26 can aid
recovery, e.g., 70% of
the initial pressure (as provided at the outlet of the water heater 14 to the
delivery system 18), such
that the injected fluid has ample pressure for near-wellbore reservoir
fracture and drive
mechanisms.
[0041] A stream of hydrocarbon fluids 32 is recovered from the reservoir 24,
typically via a
submersible pump 34 and/or a high pressure pump 36 at a pressure in the range
of about 3200 to
3500 psig at the pump 36 discharge and is output into a high pressure producer
wellbore or oil
gathering pipeline stream 38. The producer wellbore or high pressure oil
gathering pipeline stream
38 can be heated via a heat exchanger 40 to a temperature in the range of
about 374 C to 400 C
by thermal transfer from the pipeline feed stream 22, and the stream 38 is
thereby heated to form
an output stream 42.
[0042] The pipeline feed stream 22 is output from the heat exchanger 40 as an
output stream 44.
Date Recue/Date Received 2023-07-14
In one embodiment, the stream 44 is mixed with stream 42, thereby resulting in
the mixing of the
supercritical phase water of stream 44 and the hydrocarbons of stream 42. The
oil and water from
streams 38 and 22 should typically have sufficient thermal energy and be
subject to sufficient
mixing so that the combined stream 46 has conditions sufficient to upgrade at
least a portion of the
hydrocarbons as it flows through a wellbore or production pipeline downstream
of the mixing.
[0043] After the two streams 42, 44 are mixed; they are allowed to react under
temperature and
pressure conditions of supercritical water, i.e., supercritical water
conditions, in the absence of
externally added hydrogen, for a residence time sufficient to allow at least
partial upgrading
reactions to occur. The reaction can be allowed to occur in the absence of
externally added catalysts
or promoters, or such catalysts and promoters can be used in accordance with
other embodiments
of the present disclosure.
[0044] "Hydrogen" as used herein in the phrase, "in the absence of externally
added hydrogen,"
means hydrogen gas. This phrase is not intended to exclude all sources of
hydrogen that are
available as reactants. Other molecules, such as saturated hydrocarbons, may
act as a hydrogen
source during the reaction by donating hydrogen to other unsaturated
hydrocarbons. In addition,
H<sub>2</sub> may be formed in-situ during the reaction through steam reforming of
hydrocarbons and
water-gas -shi ft reaction.
[0045] Supercritical water conditions typically include a temperature from 374
C (the critical
temperature of water) to 1000 C, preferably from 374 C to 600 C and most
preferably from 374 C
to 455 C, a pressure from 3,205 (the critical pressure of water) to 10,000
psia, preferably from
3,205 psia to 7,200 psia and most preferably from 3,205 to 4,060 psia, an
oil/water volume ratio
from 1:0.1 to 1:10, preferably from 1:0.5 to 1:3 and most preferably about 1:1
to 1:2.
[0046] The reactants of the combined stream 46 are allowed to react under
these conditions for a
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Date Recue/Date Received 2023-07-14
sufficient time to allow at least partial upgrading reactions to occur, i.e.,
for a reduction in viscosity.
The residence time can be selected to allow the upgrading reactions to occur
selectively and to the
fullest extent without having undesirable side reactions of coking or residue
formation. Typical
residence times may be from 1 minute to 6 hours, preferably from 8 minutes to
2 hours and most
preferably from 20 to 40 minutes.
[0047] While not being bound to any theory of operation, it is believed that a
number of upgrading
reactions are occurring simultaneously at the supercritical reaction
conditions used in the present
process. In a preferred embodiment of the disclosure the major chemical
upgrading reactions are
believed to be:
Thermal Cracking: CHy--0.1 ightbr hydrocarbons
Skarn Reforming: CxHy+2 x1120=x0324-(2x+y/2)112
WaterCras-S.h i ft. CO+H 00 +H
= 2 2 2
Demetal i 7 at ion: C,õ,FriN +If 20/132-44.; ) -"N i (OH )2+
Ligh tor hydrocarbons
Dem ilfutintirm: C",,S.+1120/H2-112S+Iighter hydro-
arixar s
[0048] The exact pathway may depend on the wellbore or pipeline conditions
(temperature,
pressure, oil/water volume ratio) and the hydrocarbon feedstock.
100491 The combined stream 46 is input to a heat exchanger 48, in which
thermal energy from the
combined stream is transferred to the stream of boiler feed water 12, thereby
cooling the production
hydrocarbons in the combined stream 46 and preheating the boiler feed water 12
before the feed
12
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water 12 enters the water heater 14. The pressure of the combined stream 50
exiting the heat
exchanger 48 can be reduced to an appropriate pressure for transportation of
the partially upgraded,
lower viscosity production stream to an upgrader or refinery for further
processing. In some cases,
the upgrading accomplished by the combination of the streams 38, 22 can
eliminate the need for a
conventional field upgrader.
[0050] In other embodiments of the present disclosure, the upgrading aspect
described above can
be accomplished in other manners. For example, the pipeline feed stream 22 can
be provided
separately from the reservoir feed stream 20 and/or by a separate heating
device. Alternatively, the
upgrading operation that is illustrated in FIG. 1 can be omitted from the
system 10. For example,
the system 10 illustrated in FIG. 2 is configured to provide the stream 16 as
the reservoir feed
stream, i.e., without splitting the stream 16 to provide a pipeline feed
stream 22. The system of
FIG. 2 also omits the heat exchanger 40 of FIG. 1. The stream 38 is not
combined with a stream of
supercritical water but is instead provided to the heat exchanger 48 for pre-
heating the feed water
12. The stream 38 then exits the heat exchanger 48 and can be transported to a
refinery for
upgrading and/or further processing.
[0051] Additional Embodiments
100521 In one aspect the present application pertains to a process for
recovering hydrocarbons, the
process generally comprises making a supercritical dense phase fluid
comprising water suitable for
heating hydrocarbons. The supercritical dense phase fluid may be made in any
convenient manner
using conventional equipment. Generally, the supercritical dense phase fluid
is generated by
heating water to a supercritical dense phase. Typically, this is conducted at
a temperature of from
374 C to 1000 C and a pressure from 3205 to 10000 psia. The supercritical
dense phase fluid may
be made at a surface location or below ground near in an underground
hydrocarbon reservoir or
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Date Recue/Date Received 2023-07-14
both. In some embodiments the supercritical dense phase is made using an
oilfield steam generator
(forced flow or otherwise) as shown in, for example, figures 3-7.
100531 The supercritical phase fluid may then be isentropically expanded to a
range of from about
60%, or from about 70%, or from about 80%, or from about 90% up to about 100%
steam quality
of subcriti cal or superheated steam. Isentropic expansion is used herein to
mean that the expansion
is substantially adiabatic and/or substantially reversible. That is, the
majority, e.g., greater than
60%, or greater than 80%, or greater than 90%, or greater than 99% of the
mechanical energy of
water is not extracted. Alternatively or additionally, the isentropic or
adiabatic efficiency is, for
example, greater than 60%, or greater than 80%, or greater than 90%, or
greater than 95%, or even
greater than 99%.
100541 The specific isentropic expansion device employed in the process and/or
system is not
particularly critical so long as the desired steam quality output is obtained.
In some embodiments,
one or more, or two or more, or even three or more isentropic devices may be
employed in a
particular system or process. Typically, such devices employ a flow path
geometry that lead to the
desired isentropic effect and/or desired steam quality. Suitable such devices
include flow control
devices such as an orifice that reduces fluid pressure due to, for example,
constriction such as the
venturi chokes described above.
100551 The location of one or more isentropic devices and corresponding
isentropic expansion may
vary depending upon the type of system, equipment employed, desired steam
quality, type of
hydrocarbons, etc. Typically, the device or devices are located at or near a
location where high
quality or superheated steam is desired. In some systems that employ, for
example, a distribution
piping system operably connected to an oilfield steam generator, one or more
isentropic expansion
devices may be upstream or downstream or both of the distribution piping
system. Similarly, for
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Date Recue/Date Received 2023-07-14
systems that may include an injection system for injecting supercritical
fluid, subcritical fluid, or
superheated steam, one or more isentropic devices may be upstream or
downstream or both of the
injection system. For example, one or more isentropic devices may be located
at or near an outlet
or inlet of one or more of a boiler, a pipe system, or an injection system.
Thus, one or more devices
may be located (a) at or near an outlet of a superheater of, for example, an
oilfield steam generator,
and/or (b) at or near an inlet or outlet of a distribution piping system,
and/or (c) at or near an inlet
or outlet of an injection system, and/or (d) at, near, or within a hydrocarbon
reservoir, and/ or (e)
at or near a subsurface location, and/or (f) any combination of the
aforementioned potential
locations.
[0056] After isentropic expansion to make a desired quality of subcritical or
superheated steam,
e.g., isentropically expanded supercritical phase fluid, the steam may be
contacted with
hydrocarbons. The hydrocarbons may be at any suitable location but typically
are within an
underground or subsea hydrocarbon reservoir.
[0057] Figure 3 shows a simplified block diagram showing a fluid injection
into a hydrocarbon
reservoir in the absence of isentropic expansion. Figure 3 employs an oilfield
steam generator with
forced flow to generate subcritical fluid. The subcritical fluid is then sent
to an injection system
through a distribution piping system. The injection system then delivers the
subcritical fluid to a
hydrocarbon reservoir.
[0058] Figures 4-6 show representative embodiments for a supercritical system.
In contrast to the
the subcritical system in Figure 3 the oilfield steam generator in the
supercritical systems of Figures
4-6 employ a superheater in the path of the gas and water flow. The
superheater may be preceded
by the removal of total dissolved solids if desired. The type and capacity of
superheater is not
particularly critical so long as the desired fluid output parameters of
temperature, pressure, flow
Date Recue/Date Received 2023-07-14
rate, etc. can be reached. As shown in Figures 4-6 one or more expansion/flow
control devices can
be located in one or places within the systems to be used as an isentropic
expansion device. While
each of Figures 4-6 show only one expansion/flow control device it should be
understood that there
may be multiple devices in multiple combinations.
[0059] Figure 7 shows a general concept of supercritical water generation in a
once through steam
generator (OTSG) using an economizer, radiant section, and superheater. The
number of tubes,
diameters, and volume of the economizer, radiant section, and superheater of
course can vary
depending upon the number of passes, desired throughput, desired capacity and
other factors.
Similarly, while figure 7 refers to field venturi for pressure reduction it
should be understood that
any isentropic device or devices may be employed instead of, or in addition
to, venturi. Of course,
a once through steam generator is not critical to the systems and processes
employed and any
convenient manner may be employed to generate the supercritical water that is
sent to the field
venturi, e.g., isentropic expansion devices for pressure reduction.
[0060] Other definitions
[0061] The terms "comprise" (as well as forms, derivatives, or variations
thereof, such as
"comprising" and "comprises") and "include" (as well as forms, derivatives, or
variations thereof,
such as "including" and "includes") are inclusive (i.e., open-ended) and do
not exclude additional
elements or steps. For example, the terms "comprises" and/or "comprising,"
when used in this
specification, specify the presence of stated features, integers, steps,
operations, elements, and/or
components, but do not preclude the presence or addition of one or more other
features, integers,
steps, operations, elements, components, and/or groups thereof. Accordingly,
these terms are
intended to not only cover the recited element(s) or step(s), but may also
include other elements
or steps not expressly recited. Furthermore, as used herein, the use of the
terms "a" or "an" when
16
Date Recue/Date Received 2023-07-14
used in conjunction with an element may mean "one," but it is also consistent
with the meaning of
"one or more," "at least one," and "one or more than one." Therefore, an
element preceded by "a"
or "an" does not, without more constraints, preclude the existence of
additional identical elements.
[0062] The use of the term "about" applies to all numeric values, whether or
not explicitly
indicated. This term generally refers to a range of numbers that one of
ordinary skill in the art
would consider as a reasonable amount of deviation to the recited numeric
values (i.e., having the
equivalent function or result). For example, this term can be construed as
including a deviation of
percent of the given numeric value provided such a deviation does not alter
the end function
or result of the value. Therefore, a value of about 1% can be construed to be
a range from 0.9%
to 1.1%. Furthermore, a range may be construed to include the start and the
end of the range. For
example, a range of 10% to 20% (i.e., range of 10%-20%) includes 10% and also
includes 20%,
and includes percentages in between 10% and 20%, unless explicitly stated
otherwise
herein. Similarly, a range of between 10% and 20% (i.e., range between 10% -
20%) includes
10% and also includes 20%, and includes percentages in between 10% and 20%,
unless explicitly
stated otherwise herein.
[0063] The term "if' may be construed to mean "when" or "upon" or "in response
to determining"
or "in accordance with a determination" or "in response to detecting," that a
stated condition
precedent is true, depending on the context. Similarly, the phrase "if it is
determined [that a stated
condition precedent is truer or "if [a stated condition precedent is truer or
"when [a stated
condition precedent is truer may be construed to mean "upon determining" or
"in response to
determining" or "in accordance with a determination" or "upon detecting" or
"in response to
detecting" that the stated condition precedent is true, depending on the
context.
17
Date Recue/Date Received 2023-07-14
100641 It is understood that when combinations, subsets, groups, etc. of
elements are disclosed
(e.g., combinations of components in a composition, or combinations of steps
in a method), that
while specific reference of each of the various individual and collective
combinations and
permutations of these elements may not be explicitly disclosed, each is
specifically contemplated
and described herein. By way of example, if an item is described herein as
including a
component of type A, a component of type B, a component of type C, or any
combination
thereof, it is understood that this phrase describes all of the various
individual and collective
combinations and permutations of these components. For example, in some
embodiments, the
item described by this phrase could include only a component of type A. In
some embodiments,
the item described by this phrase could include only a component of type B. In
some
embodiments, the item described by this phrase could include only a component
of type C. In
some embodiments, the item described by this phrase could include a component
of type A and a
component of type B. In some embodiments, the item described by this phrase
could include a
component of type A and a component of type C. In some embodiments, the item
described by
this phrase could include a component of type B and a component of type C. In
some
embodiments, the item described by this phrase could include a component of
type A, a
component of type B, and a component of type C. In some embodiments, the item
described by
this phrase could include two or more components of type A (e.g., Al and A2).
In some
embodiments, the item described by this phrase could include two or more
components of type B
(e.g., B1 and B2). In some embodiments, the item described by this phrase
could include two or
more components of type C (e.g., Cl and C2). In some embodiments, the item
described by this
phrase could include two or more of a first component (e.g., two or more
components of type A
(Al and A2)), optionally one or more of a second component (e.g., optionally
one or more
18
Date Recue/Date Received 2023-07-14
components of type B), and optionally one or more of a third component (e.g.,
optionally one or
more components of type C). In some embodiments, the item described by this
phrase could
include two or more of a first component (e.g., two or more components of type
B (B1 and B2)),
optionally one or more of a second component (e.g., optionally one or more
components of type
A), and optionally one or more of a third component (e.g., optionally one or
more components of
type C). In some embodiments, the item described by this phrase could include
two or more of a
first component (e.g., two or more components of type C (Cl and C2)),
optionally one or more
of a second component (e.g., optionally one or more components of type A), and
optionally one
or more of a third component (e.g., optionally one or more components of type
B).
[0065] This written description uses examples to disclose the invention,
including the best mode,
and also to enable any person skilled in the art to make and use the
invention. The patentable
scope is defined by the claims, and may include other examples that occur to
those skilled in the
art. Such other examples are intended to be within the scope of the claims if
they have elements
that do not differ from the literal language of the claims, or if they include
equivalent elements
with insubstantial differences from the literal language of the claims.
100661 Unless defined otherwise, all technical and scientific terms used
herein have the same
meanings as commonly understood by one of skill in the art to which the
disclosed invention
belongs.
[0067] Many modifications and other embodiments of the present disclosure set
forth herein will
come to mind to one skilled in the art to which the present disclosure
pertains having the benefit
of the teachings presented in the foregoing descriptions and the associated
drawings. Therefore, it
is to be understood that the present disclosure is not to be limited to the
specific embodiments
disclosed and that modifications and other embodiments are intended to be
included within the
19
Date Recue/Date Received 2023-07-14
scope of the appended claims. Although specific terms are employed herein,
they are used in a
generic and descriptive sense only and not for purposes of limitation.
[0068] SPECIFIC EMBODIMENTS
[0069] Embodiment 1. A process for recovering hydrocarbons, comprising:
making a first supercritical dense phase fluid comprising water suitable for
heating
hydrocarbons, wherein the first supercritical dense phase fluid is generated
by heating water to a
supercritical dense phase at a temperature from 374 C to 1000 C and a pressure
from 3205 to
10000 psia at a surface location; and
flashing the first supercritical phase fluids to a range of about 70% to 100%
steam quality
or superheated steam to heat the hydrocarbons with the about 70% to 100% steam
quality or
superheated steam.
[0070] Embodiment 2. The process according to embodiment 1, wherein the
flashing is
across one or more venturi chokes.
[0071] Embodiment 3. The process according to embodiment 1, wherein the
temperature is
in a range of 374 C to 600 C and the pressure is from 3205 to 7200 psia.
[0072] Embodiment 4. The process according to embodiment 1, wherein the
temperature is
in a range of about 374 C to 455 C and the pressure is from about 3205 to 4060
psia.
[0073] Embodiment 5. The process according to embodiment 1, wherein the
first
supercritical dense phase fluid is output from an oilfield water heater into a
high pressure piping
having a diameter in a range of about 6 to 61 cm.
[0074] Embodiment 6. The process according to embodiment 1, wherein the
volume ratio
of the hydrocarbons to the supercritical dense phase fluid comprising water is
from 1:0.1 to 1:10.
Date Recue/Date Received 2023-07-14
[0075] Embodiment 7. The process according to embodiment 1, further
comprising: mixing
a second supercritical dense phase fluid comprising water with the heated
hydrocarbons to upgrade
at least a portion of the heated hydrocarbons, wherein the step of upgrading
comprises reducing
the viscosity of at least a portion of the heated hydrocarbons.
[0076] Embodiment 8. The process according to embodiment 7, wherein the
first
supercritical dense phase fluid and the second supercritical dense phase fluid
are generated from a
modified oilfield steam generator at a surface location or modified heat
recovery steam generator
at a surface location.
[0077] Embodiment 9. A system for recovering hydrocarbons, the system
comprising:
a supercritical phase fluid comprising water heated to a temperature from 374
C to 1000 C
at a pressure from 3205 to 10000 psia;
a delivery system configured to receive the supercritical phase fluid and
deliver the
supercritical phase fluid to hydrocarbons to heat the hydrocarbons to reduce
viscosity of at least
a portion of the hydrocarbons, wherein the delivery system is configured such
that the supercritical
phase fluid drops in pressure and flashes to a range of about 70% to 100%
steam quality or
superheated steam prior to contacting the hydrocarbons; and
a well configured to recover the heated hydrocarbons.
[0078] Embodiment 10. The system according to embodiment 9, wherein the
water is at a
temperature of from 374 C to 600 C at a pressure of from 3205 to 7200 psia and
wherein the
delivery system further comprises high pressure piping having a diameter in a
range of about 6 to
61 cm.
[0079] Embodiment 11. The system according to embodiment 9, wherein the
delivery system
further comprises venturi chokes.
21
Date Recue/Date Received 2023-07-14
[0080] Embodiment 12. A process for recovering hydrocarbons, comprising:
making a supercritical dense phase fluid comprising water suitable for heating
hydrocarbons, wherein the supercritical dense phase fluid is generated by
heating water to a
supercritical dense phase at a temperature from 374 C to 1000 C and a pressure
from 3205 to
10000 psia at a surface location;
isentropically expanding the supercritical phase fluids to a range of about
70% to 100%
steam quality or superheated steam to heat the hydrocarbons with the about 70%
to 100% steam
quality or superheated steam.
[0081] Embodiment 13. The process of embodiment 12, wherein the
supercritical phase
fluids are isentropically expanded by an isentropic expansion device.
[0082] Embodiment 14. The process of embodiment 12, which further comprises
injecting
the isentropically expanded supercritical phase fluids into a hydrocarbon
reservoir.
[0083] Embodiment 15. The process of embodiment 12, which further comprises
injecting
the supercritical phase fluids into a hydrocarbon reservoir prior to the
isentropically expanding.
[0084] Embodiment 16. The process of embodiment 13, wherein the isentropic
expansion
device is located at or near an outlet of one or more of a boiler, a pipe
system, or an injection
system, or at a subsurface location, or any combination thereof.
[0085] Embodiment 17. A system comprising:
a distribution piping system configured to receive a subcritical phase fluid,
a supercritical
phase fluid, or any combination thereof;
an isentropic expansion device operably connected to the distribution piping
system
wherein the isentropic expansion device is configured to expand the
subcritical phase fluid, the
supercritical phase fluid, or any combination thereof to a range of from about
70% to 100% steam
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Date Recue/Date Received 2023-07-14
quality or superheated steam prior to said 70% to 100% steam quality or
superheated steam heating
one or more hydrocarbons; and
a well configured to recover heated hydrocarbons.
[0086] Embodiment 18. The system of embodiment 17, wherein the system is
configured
such that isentropic expansion device is either upstream or downstream of the
distribution piping
system.
[0087] Embodiment 19. The system of embodiment 17, wherein the system
further
comprises a superheater configured to make a supercritical phase fluid
comprising water heated to
a temperature from 374 C to 1000 C at a pressure from 3205 to 10000 psi a
wherein the superheater
is operably connected to the distribution piping system.
[0088] Embodiment 20. The system of embodiment 17, wherein the system
further
comprises an injection system operably connected to the distribution piping
system wherein the
injection system is configured to inject one or more of the following into a
hydrocarbon reservoir:
a subcritical phase fluid, a supercritical phase fluid, 70% to 100% steam
quality or superheated
steam, or any combination thereof.
[0089] Embodiment 21. The system of embodiment 20, wherein the system is
configured
such that isentropic expansion device is either upstream or downstream of the
injection system.
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