U.S. patent application number 12/847016 was filed with the patent office on 2012-02-02 for subsurface heater.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. Invention is credited to Kelly Roy Fletcher, Michael Solomon Idelchik, Narendra Digamber Joshi, Sherif Hatem Abdulla Mohamed.
Application Number | 20120028201 12/847016 |
Document ID | / |
Family ID | 44898768 |
Filed Date | 2012-02-02 |
United States Patent
Application |
20120028201 |
Kind Code |
A1 |
Mohamed; Sherif Hatem Abdulla ;
et al. |
February 2, 2012 |
SUBSURFACE HEATER
Abstract
In one aspect, the present invention provides a subsurface
heater comprising: a combustible gas supply conduit; an oxygen
supply conduit and a heat transmissive external housing
encompassing a porous refractory medium. The combustible gas supply
conduit and the oxygen supply conduit are configured as a
concentric pair disposed within the porous refractory medium and
coupled to a plurality of gas jets disposed within the porous
refractory medium. The porous refractory medium has disposed within
it a plurality of combustion product gas return conduits. The
combustion product gas return conduits are configured to receive
combustion product gases from the porous refractory medium. Also
provided in another aspect of the present invention, is a method
for heating a subsurface zone.
Inventors: |
Mohamed; Sherif Hatem Abdulla;
(Niskayuna, NY) ; Joshi; Narendra Digamber;
(Schenectady, NY) ; Idelchik; Michael Solomon;
(Niskayuna, NY) ; Fletcher; Kelly Roy; (Niskayuna,
NY) |
Assignee: |
GENERAL ELECTRIC COMPANY
SCHENECTADY
NY
|
Family ID: |
44898768 |
Appl. No.: |
12/847016 |
Filed: |
July 30, 2010 |
Current U.S.
Class: |
432/3 ;
126/85R |
Current CPC
Class: |
E21B 36/02 20130101;
F23C 3/004 20130101; E21B 43/24 20130101; F23C 99/006 20130101 |
Class at
Publication: |
432/3 ;
126/85.R |
International
Class: |
F24C 3/00 20060101
F24C003/00 |
Claims
1. A subsurface heater comprising: a combustible gas supply conduit
and an oxygen supply conduit configured as a concentric pair
disposed within a porous refractory medium and coupled to a
plurality of gas jets disposed within the porous refractory medium,
the porous refractory medium having disposed within it a plurality
of combustion product gas return conduits, the combustion product
gas return conduits being configured to receive combustion product
gases from the porous refractory medium; and a heat transmissive
external housing encompassing the porous refractory medium.
2. The subsurface heater according to claim 1, wherein the porous
refractory medium is at least one selected from the group
consisting of alumina, silica, zirconia, silicon carbide,
alumina-silicon dioxide, zirconia-alumina composites, and metals
balls including metals such as iron, or iron based alloys.
3. The subsurface heater according to claim 1, wherein the porous
refractory medium is selected from the group consisting of alumina,
silica, carbon and silt.
4. The subsurface heater according to claim 1, wherein the gas jets
precess about a central axis defined by the gas supply
conduits.
5. The subsurface heater according to claim 1, wherein the gas jets
are independently operable.
6. The subsurface heater according to claim 1, wherein the
combustion product gas return conduits are symmetrically disposed
within the porous refractory medium.
7. The subsurface heater according to claim 1, wherein the
combustion product gas return conduits are located on the periphery
of the porous refractory medium and adjacent to an inner surface of
the heat transmissive external housing.
8. The subsurface heater according to claim 1, wherein the
combustion product gas return conduits are independently
operable.
9. The subsurface heater according to claim 1, further comprising a
plurality of temperature sensors.
10. The subsurface heater according to claim 9, wherein the
temperature sensors are configured to provide data to a control
system.
11. The subsurface heater according to claim 1, wherein the
combustion product gas return conduits are spaced in a cluster in
the porous refractory medium.
12. A method for heating a subsurface zone, comprising: (a)
creating an accommodation cavity for a subsurface heater comprising
a combustible gas supply conduit and an oxygen supply conduit
configured as a concentric pair disposed within a porous refractory
medium and coupled to a plurality of gas jets disposed within the
porous refractory medium, the porous refractory medium having
disposed within it a plurality of combustion product gas return
conduits, the combustion product gas return conduits being
configured to receive combustion product gases from the porous
refractory medium; and a heat transmissive external housing
encompassing the porous refractory medium; (b) installing the
subsurface heater; and (c) operating the subsurface heater.
13. The method according to claim 1, wherein the combustible
product gas is at least one selected from the group consisting of
nitrogen, oxygen, carbon dioxide, and water vapor.
14. The method according to claim 1, wherein the accommodation
cavity is created in a hydrocarbon reservoir.
15. The method according to claim 1, wherein the accommodation
cavity is created in a near-surface zone.
16. A subsurface heater comprising: a combustible gas supply
conduit and an oxygen supply conduit configured as a concentric
pair disposed within a porous refractory medium and coupled to a
plurality of gas jets disposed within the porous refractory medium,
the porous refractory medium having disposed within it a plurality
of combustion product gas return conduits, the combustion product
gas return conduits being configured to receive combustion product
gases from the porous refractory medium; and a heat transmissive
external housing encompassing the porous refractory medium and
wherein the plurality of gas jets are independently operable.
17. The subsurface heater according to claim 16, wherein the porous
refractory medium is at least one selected from the group
consisting of alumina, silica, zirconia, silicon carbide,
alumina-silicon dioxide, zirconia-alumina composites, and metals
balls including metals such as iron, or iron based alloys.
18. The subsurface heater according to claim 16, wherein the gas
jets precess about a central axis defined by the gas supply
conduits.
19. The subsurface heater according to claim 16, further comprising
a plurality of temperature sensors configured to provide data to a
control system.
20. The subsurface heater according to claim 16, wherein the
combustion product gas return conduits are located on the periphery
of the porous refractory medium and adjacent to an inner surface of
the heat transmissive external housing.
Description
BACKGROUND
[0001] There are extensive hydrocarbon reservoirs distributed
throughout the world which, for the foreseeable future, represent
key energy resources for the world's continued economic
development. These reservoirs often contain a viscous hydrocarbon
concoction, called "tar," "heavy oil," or "ultra heavy oil," which
typically has a viscosity in the range from about 3,000 to
1,000,000 centipoise when measured at around 37.5.degree. C. Many
hydrocarbon bearing geologic formations contain such hydrocarbon
concoctions which do not permit a ready flow of the hydrocarbon
content to a wellbore for extraction because of their high
viscosity. In certain hydrocarbon reservoirs, for example, oil
shale reservoirs, the hydrocarbon components must be thermally
broken down into lower molecular weight compounds in order to
effect their recovery from the reservoir. In certain instances, the
reservoir must be heated to a temperature in excess of 300.degree.
C. in order to effect even the partial extraction of hydrocarbons
from a hydrocarbon reservoir.
[0002] Three different types of processes are known to enhance
hydrocarbon extraction from subterranean hydrocarbon reservoirs.
These processes may be classified generally as thermal processes,
chemical processes and miscible displacement processes.
[0003] A notable, known thermal process involves an "in situ"
combustion technique in which the reservoir, serving as its own
fuel source, is ignited through an injection well and a zone of
combustion is propagated from the injection well towards a
production well. The combustion can be somewhat controlled by the
position of the injection well and the mode of delivery of the
exogenous oxygen needed to effect combustion within the combustion
zone. Because of the nature and complexity of the fuel involved,
such in situ combustion techniques produce a complex variety of
combustion product gases which must be carefully managed in order
to prevent their uncontrolled release into the living
environment.
[0004] Heat conduction phenomena within and around the reservoir
may play a critical role in hydrocarbon recovery rates, and such
rates may be further limited by a tendency of the hydrocarbon
components of the reservoir to undergo coking. The heat transfer
rate from a heat source to the reservoir may be limited by the
coking temperature and the ambient temperature of the hydrocarbon
bearing reservoir. Thus, methods involving heating of a hydrocarbon
reservoir must balance the rate at which heat is introduced into
the reservoir against the coking temperature of the hydrocarbon
components of the reservoir and the rate at which the heat can be
conducted from the heat source into the reservoir.
[0005] Therefore there is a need for subsurface heating devices
which utilize clean fuels such as natural gas and effect a
controlled delivery of substantial amounts of heat from the device
to the reservoir such that coking may be minimized while maximizing
the efficiency of hydrocarbon recovery.
BRIEF DESCRIPTION
[0006] In one aspect, the present invention provides a subsurface
heater comprising: a combustible gas supply conduit; an oxygen
supply conduit and a heat transmissive external housing
encompassing the porous refractory medium. The combustible gas
supply conduit and the oxygen supply conduit are configured as a
concentric pair disposed within a porous refractory medium and
coupled to a plurality of gas jets disposed within the porous
refractory medium. The porous refractory medium having disposed
within it a plurality of combustion product gas return conduits.
The combustion product gas return conduits are configured to
receive combustion product gases from the porous refractory
medium.
[0007] In another aspect, the present invention provides a method
for heating a subsurface zone, comprising: (a) creating an
accommodation cavity for a subsurface heater; (b) installing the
subsurface heater; and (c) operating the subsurface heater. The
subsurface heater comprises a combustible gas supply conduit and an
oxygen supply conduit configured as a concentric pair disposed
within a porous refractory medium and coupled to a plurality of gas
jets disposed within the porous refractory medium, the porous
refractory medium having disposed within it a plurality of
combustion product gas return conduits, the combustion product gas
return conduits being configured to receive combustion product
gases from the porous refractory medium; and a heat transmissive
external housing encompassing the porous refractory medium.
[0008] In yet another aspect, the present invention provides a
subsurface heater comprising: a combustible gas supply conduit; an
oxygen supply conduit and a heat transmissive external housing
encompassing the porous refractory medium. The combustible gas
supply conduit and the oxygen supply conduit are configured as a
concentric pair disposed within a porous refractory medium and
coupled to a plurality of gas jets disposed within the porous
refractory medium. The porous refractory medium having disposed
within it a plurality of combustion product gas return conduits.
The combustion product gas return conduits are configured to
receive combustion product gases from the porous refractory medium.
The plurality of gas jets are independently operable.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0009] These and other features, aspects, and advantages of the
present invention will become better understood when the following
detailed description is read with reference to the accompanying
drawings in which like characters represent like parts throughout
the drawings, wherein:
[0010] FIG. 1 is a cross-section of a subsurface heater in
accordance with an embodiment of the invention.
[0011] FIG. 2 is a sectional view of a subsurface heater in
accordance with an embodiment of the invention.
[0012] FIG. 3 is a section of a subsurface heater in accordance
with an embodiment of the invention.
[0013] FIG. 4 is a section of a subsurface heater in accordance
with an embodiment of the invention.
[0014] FIG. 5 is a section of a subsurface heater in accordance
with an embodiment of the invention.
DETAILED DESCRIPTION
[0015] In the following specification and the claims, which follow,
reference will be made to a number of terms, which shall be defined
to have the following meanings.
[0016] The singular forms "a", "an" and "the" include plural
referents unless the context clearly dictates otherwise.
[0017] "Optional" or "optionally" means that the subsequently
described event or circumstance may or may not occur, and that the
description includes instances where the event occurs and instances
where it does not.
[0018] It is also understood that terms such as "top," "bottom,"
"outward," "inward," and the like are words of convenience and are
not to be construed as limiting terms. Furthermore, whenever a
particular feature of the invention is said to comprise or consist
of at least one of a number of elements of a group and combinations
thereof, it is understood that the feature may comprise or consist
of any of the elements of the group, either individually or in
combination with any of the other elements of that group.
[0019] Approximating language, as used herein throughout the
specification and claims, may be applied to modify any quantitative
representation that could permissibly vary without resulting in a
change in the basic function to which it is related. Accordingly, a
value modified by a term or terms, such as "about", is not to be
limited to the precise value specified. In some instances, the
approximating language may correspond to the precision of an
instrument for measuring the value. Similarly, "free" may be used
in combination with a term, and may include an insubstantial
number, or trace amounts, while still being considered free of the
modified term.
[0020] As discussed in detail below, embodiments of the present
invention include a subsurface heater comprising: a combustible gas
supply conduit; an oxygen supply conduit and a heat transmissive
external housing encompassing the porous refractory medium. The
combustible gas supply conduit and the oxygen supply conduit are
configured as a concentric pair disposed within a porous refractory
medium and coupled to a plurality of gas jets disposed within the
porous refractory medium. The porous refractory medium having
disposed within it a plurality of combustion product gas return
conduits. The combustion product gas return conduits are configured
to receive combustion product gases from the porous refractory
medium.
[0021] In one embodiment of the present invention, as illustrated
by FIG. 1, the subsurface heater 10 includes a combustion gas
supply conduit 12 and an oxygen supply conduit 14. In one
embodiment, the combustion gas supply conduit 12 and oxygen supply
conduit 14 form a concentric pair. In another embodiment, the
combustion gas supply conduit 12 and oxygen supply conduit 14 can
be placed parallel to each other (for example a side by side type
of arrangement). In one embodiment, the combustion gas can be
selected from the group consisting of natural gas, hydrocarbons
such as methane, propane etc, a premix of methane and air, kerosene
type jet fuel and the like. In another embodiment, the combustion
gas supply conduit 12 forms an inner conduit of the concentric
pair. In yet another embodiment, the combustion gas supply conduit
12 forms an outer conduit of the concentric pair.
[0022] In one embodiment, the oxygen supply conduit 14 can carry
gas selected from air, inert gases such as argon, nitrogen, air
enriched with oxygen, synthetic mixtures of oxygen and one or more
gases, and the like. In another embodiment, the oxygen supply
conduit 14 can carry gas that contains at least about 70 percent by
weight of oxygen. In yet another embodiment, the oxygen supply
conduit 14 can carry gas that contains at least about 90 percent by
weight of oxygen.
[0023] The subsurface heater includes a heat transmissive external
housing 18. The heat transmissive external housing 18 encompasses a
porous refractory medium 20. In one embodiment, the area between
the outer conduit of the concentric pair and the heat transmissive
external housing 18 contains the porous refractory medium 20. In
one embodiment, the porous refractory medium 20 includes materials
that are heat resistant. Non-limiting examples of the materials
that can be present in the porous refractory medium 20 include
ceramic materials such as alumina, silica, zirconia, silicon
carbide, alumina-silicon dioxide (mullite), zirconia-alumina
composites, metals balls including metals such as iron, or iron
based alloys. In another embodiment, the porous refractory medium
20 includes at least one material selected from the group
consisting of alumina, silica, carbon, and silt.
[0024] In one embodiment, the combustion gas supply conduit 12 and
the oxygen supply conduit 14 that are configured as a concentric
pair disposed within the porous refractory medium 20. The
combustion gas supply conduit 12 and the oxygen supply conduit 14
are coupled to a plurality of gas jets 24 (as shown in FIG. 2). In
one embodiment, the gas jets 24 can precess about a central axis
defined by the combustion gas supply conduit 12 and the oxygen
supply conduit 14. Thus, the positions of the gas jets 24 and
associated oxygen (air) nozzles 22 may vary with respect to a
reference position defined for the axis defined by the combustion
gas supply conduit 12 and oxygen supply conduit 14 and is referred
to herein as a movement of precession. In one embodiment, the
movement of precession can be comprised of regular rotational
intervals with respect to a reference position. In one embodiment,
one of the plurality of gas jets 24 represents the reference
position and is denominated as 0 degrees of rotation, while a
second adjacent gas jet is precessed with respect to the first gas
jet by about 90 degrees of rotation, while the third gas jet
adjacent to the second gas jet is precessed with respect to the
first gas jet by about 180 degrees of rotation, while a fourth gas
jet adjacent to the third gas jet is precessed with respect to the
first gas jet by about 270 degrees of rotation, and a fifth gas jet
adjacent to the fourth gas jet is precessed with respect to the
first gas jet by about 0 degrees of rotation. Those of ordinary
skill in the art will appreciate that various configurations of the
plurality of gas jets 24 and associated oxygen (air) nozzles 22 are
possible. In one embodiment, groupings of the plurality of gas jets
24 and associated oxygen (air) nozzles 22 may precess about the
axis defined by the combustion gas supply conduit 12 and oxygen
supply conduit 14.
[0025] In another series of embodiments, the movement of precession
can be random or discontinuous. In yet another embodiment, there is
no precession of the plurality of gas jets 24 and associated oxygen
(air) nozzles 22 about a reference position along the axis defined
by the combustion gas supply conduit 12 and the oxygen supply
conduit 14.
[0026] In one embodiment, each one of the plurality of gas jets 24
and associated oxygen (air) nozzles 22 (together referred to as
"burners") are independently operable i.e. a burner can be switched
on or off independently without affecting the status of other
burners in the subsurface heater. Thus, in one embodiment, during
operation a first plurality of burners located at a reference
position denominated 0 degrees along the axis defined by the
combustion gas supply conduit 12 and oxygen supply conduit 14 are
"switched on" (i.e. the plurality of gas jets 24 and associated
oxygen (air) nozzles 22 are open and the oxygen-fuel mixture
emerging therefrom is burning) while a second plurality of burners
located at a reference position denominated 180 degrees along the
axis defined by the combustion gas supply conduit 12 and oxygen
supply conduit 14 are "switched off" (i.e. gas jets 24 and
associated oxygen (air) nozzles 22 are closed). In yet another
embodiment, the amount of heat produced at any given time by any
one of the plurality of gas jets 24 can be varied independently by
varying parameters such as pressure of the combustion gas, pressure
of the oxygen, or varying the ratio of the oxygen to the combustion
gas.
[0027] In various embodiments, the plurality of gas jets 24 and
associated oxygen (air) nozzles 22 may be controlled such that they
are open, partially opened or closed depending on need.
Conventional control systems may be employed. In one embodiment,
the mechanical components of the burners (e.g. the gas jets 24, the
associated oxygen (air) nozzles 22, and the burner igniter) and a
set of operational sensors (flame on/off sensor, valve open/closed
sensor, temperature sensor, pressure sensor, igniter on/off sensor)
are linked to a controller via an insulated control cable arrayed
along the axis of and within the combustion gas supply conduit
12.
[0028] In one embodiment, the porous refractory medium 20 can
include three zones (not shown) that include a mixing zone, an
ignition zone and a reaction zone. The reaction zone can also be
referred to as a combustion zone as the combustion occurs at the
reaction zone. In another embodiment, the three zone present in the
porous refractory medium 20 can be easily distinguishable. In one
embodiment, the three zones can include porous refractory medium 20
having uniform particle size. In another embodiment, the particle
size of the material in the porous refractory medium 20 can vary in
the three zones. For example, the mixing zone can be packed with
small size particles, the ignition zone can be packed with larger
size particles.
[0029] In one embodiment, the porous refractory medium 20 includes
a plurality of nozzles 22, at times herein referred to as "air
nozzles", which are coupled to the oxygen supply conduit, release
an oxygen-containing gas (e.g. air, oxygen, or a synthetic mixture
of oxygen and one or more gases) into the porous refractory medium
20. In another embodiment, the air nozzle 22 and the gas jet 24 can
be form a concentric pair. In one embodiment, the mixing of the
oxygen-containing gas supplied by the oxygen supply conduit and the
combustion gas occurs in the vicinity of the plurality of gas jets
24. In one embodiment, the mixture of combustion gas and oxygen can
be ignited by an igniter, for example a small open flame burner, an
electrically heated wire, or a spark device. Once ignited the flame
may propagate into the combustion zone in the porous refractory
medium 20.
[0030] Disposed within the porous refractory medium 20 is a
plurality of combustion product gas return conduits 16. The
combustion product gas return conduits 16 are configured to receive
combustion product gases that are formed as a result of combustion
in the porous refractory medium 20. Combustion product gases are
typically comprised of carbon dioxide and water nut may include
other products as well. In one embodiment, the combustion product
gas return conduits 16 are symmetrically disposed with respect to
each other within the porous refractory medium 20. In another
embodiment, the combustion product gas return conduits 16 are
located on the periphery of the porous refractory medium 20
adjacent to an inner surface of the heat transmissive external
housing 18. In yet another embodiment, the combustion product gas
return conduits 16 can be disposed in a random or discontinuous
manner throughout the porous refractory medium 20. In another
embodiment, the combustion product gas return conduits 16 can be
disposed in a periodic manner in the porous refractory medium 20.
In yet another embodiment, the combustion product gas return
conduits 16 can be spaced in a cluster in the porous refractory
medium 20. In one embodiment, the combustion product gas return
conduits 16 include a porous outer surface that enables the flow of
the combustion product gases to flow into the conduits from the
porous refractory medium 20. In one embodiment, the combustion
product gas return conduits 16 can be independently operable. As
used herein the term "independently operable" means that at any
given time only some or all of the combustion product gas return
conduits 16 can be operable to conduct the combustion product gas
from the porous refractory medium 20. In one embodiment, the
combustion gas supply conduit 12 and oxygen supply conduit 14
disposed in the porous refractory medium 20 are configured to have
an opposed flow with the heat generated as a result of combustion,
i.e. the heat is conducted towards the central part of the porous
refractory medium 20 while the combustion gas and the oxygen flow
away from the center. In another embodiment, the combustion gas and
the oxygen are maintained at a temperature of about 50.degree. C.
which aids in lower flow velocities and reduces pressure
losses.
[0031] As will be appreciated by those of ordinary skill in the
art, the fuel and air tubes (i.e. the combustible gas supply
conduit and the oxygen supply conduit) may be in close proximity to
the combustion zone of the porous refractory medium and there is a
tendency of heat to flow toward the center of the subsurface heater
as well as being radiated outwardly from the subsurface heater. As
a result of the outward flow of the combustible gas and the oxygen
containing gas from the combustion gas supply conduit and the
oxygen supply conduit respectively, the temperature within each of
the conduits can be maintained at relatively low temperature during
operation of the subsurface burner. Lower flow velocities and lower
pressure losses are a result, of the relatively low temperatures
prevailing within the fuel and oxygen containing gas supply
conduits.
[0032] In one embodiment, the subsurface heater can further include
a plurality of temperature sensors (not shown). In one embodiment,
the temperature sensor can be disposed within the subsurface
heater. In another embodiment, the temperature sensor can be
disposed outside an outer surface of the heat transmissive external
housing 18 of the subsurface heater. In another embodiment, the
temperature sensor is configured to provide data to a control
system.
[0033] FIG. 2 is a section 30 of the subsurface heater according to
one embodiment of the invention. As illustrated in FIG. 2 the
pressurized combustion gas from the combustion gas supply conduit
12 and the oxygen from the oxygen supply conduit 14 are contacted
with the porous refractory medium 20 through the gas jet 24 and the
air nozzle 22 respectively. As illustrated in FIG. 2 the combustion
product gas return conduits 16 are disposed periphery of the porous
refractory medium 20 adjacent to an inner surface 26 of the heat
transmissive external housing 18.
[0034] FIG. 3 is a section of the subsurface heater 50 according to
one embodiment of the invention. As shown in FIG. 3 the oxygen 52
and the combustion gas 54 flow into the reaction zone 56 in the
porous refractory medium 20. In one embodiment, the propagation of
the flame is radial. The equivalence ratio contour which is defined
as an estimated contour along which the combustion gas to the
oxygen ratio is equal to the stoichiometric ratio of the combustion
gas to the oxygen. This indicates that the reaction or combustion
occurs stoichiometrically along the contour. In one embodiment, the
highest flame temperature can be experienced in the region defined
by the contour.
[0035] FIG. 4 depicts the temperature profile along a section of
the subsurface heater according to one embodiment of the invention.
The temperature profile along the heater and external to it in the
area surrounding the heater for example shale oil, is shown in FIG.
4. In the illustrated embodiment the temperature is found to be
dependent upon the distance from the axis defined by the center of
the combustion gas supply conduit 12. FIG. 5 provides data 80
demonstrating the temperature contours or isotherms 82, 84, 86, 88
and 90 within a subsurface heater during operation according to one
embodiment of the invention.
[0036] In one embodiment, the subsurface heater can be operated in
a pressurized environment. In another embodiment, the can be
operable at varying combustion gas and oxygen pressures over
several thousands of feet in length. In one embodiment, the heat
released from the combustion product gas return conduits 16 is
relatively low, for example when the average temperature of the
combustion product gases within and along the length of the
combustion product gas return conduits 16 is less than about
200.degree. C. Under such conditions the generation of NOx may be
minimal. In one embodiment, and the combustion product gases
comprise less than about 2 ppm NOx.
[0037] Another aspect of the invention provides a method for
heating a subsurface zone, comprising: (a) creating an
accommodation cavity for a subsurface heater; (b) installing the
subsurface heater; and (c) operating the subsurface heater.
[0038] In one embodiment, the accommodation cavity can be created
in a hydrocarbon reservoir. As used herein the term "hydrocarbon"
is defined as compounds comprising carbon and hydrogen. However,
hydrocarbon-containing reservoirs may contain a host of components
comprising elements other than carbon and hydrogen, for example
halogens, nitrogen, oxygen, metals, sulfur, and selenium.
Non-limiting examples of components which may be present in a
hydrocarbon reservoir include, straight chain and branched
hydrocarbons, for example eicosane (a C.sub.20 straight chain
hydrocarbon) and phytane (a C.sub.20 branched hydrocarbon),
bitumen, oil tars, minerals, asphaltites, kerogen, and the like.
The hydrocarbon reservoir is typically contained within a geologic
matrix, such as sedimentary rock, sands, silicilytes, carbonates,
diatomites, and the like. In one embodiment, the hydrocarbon
reservoir is a subterranean, viscous oil-containing formation. In
one embodiment, the hydrocarbon reservoir is contained within a
heavy oil tar sand formation. In another embodiment, hydrocarbon
reservoir is contained within a shale oil formation. In one
embodiment, the accommodation cavity can be subterranean, located
under tundra, under sea or inland based wells. The methods provided
by the present invention may be practiced in conjunction with a
wide variety of hydrocarbon recovery techniques including vertical
recovery, horizontal recovery, and steam assisted gravity drainage
(SAGD) techniques. In another embodiment, the accommodation cavity
can be created in a near-surface zone. Examples of applicable
near-surface zones include but are not limited to construction
activity zones, water containment zones, water transport zones
(e.g. municipal water delivery and waste water removal), and water
treatment zones such as municipal water treatment plants.
[0039] This written description uses examples to disclose the
invention, including the best mode, and also to enable any person
skilled in the art to practice the invention, including making and
using any devices or systems and performing any incorporated
methods. The patentable scope of the invention 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 structural elements that do not differ
from the literal language of the claims, or if they include
equivalent structural elements with insubstantial differences from
the literal languages of the claims.
* * * * *