Note: Descriptions are shown in the official language in which they were submitted.
1
GEOTHERMAL HEATING OF HYDROCARBON RESERVOIRS FOR IN SITU
RECOVERY
TECHNICAL FIELD
10001 ] The technical field generally relates to recovering hydrocarbons or
fluids, such as
heavy hydrocarbons, from a subsurface formation, and more particularly to
systems and methods
for recovering hydrocarbons from a subsurface formation aided by a geothermal
well. The
technical field also relates to the use of wells for recovering geothermal
heat from a subterranean
formation for use at surface.
BACKGROUND
10002 ] The general principle of recovering hydrocarbons, such as heavy
hydrocarbons,
from a subsurface formation involves heating the heavy hydrocarbons or
otherwise reducing the
viscosity, thereby facilitating recovery via a production well. Existing
thermal processes for
recovering heavy hydrocarbons typically require a large surface footprint with
significant
infrastructure, notably for steam generation. For example, steam-assisted
gravity drainage (SAGD)
processes require water and natural gas to generate steam at the surface so
that the steam can be
injected into the injection well for heating the heavy hydrocarbons. These
processes have
drawbacks, such as energy consumption, notable capital expenditure
requirements, and CO2
generation.
10003 ] There is therefore a need for improved technologies for recovering
hydrocarbons
from subsurface reservoirs and for leveraging geothermal heat sources for
various uses.
SUMMARY
10004 ] Various systems and methods are described herein for recovering
heavy
hydrocarbons from a subsurface formation while leveraging geothermal heat
present in a lower
zone of the formation. Drawing the geothermal heat up to the heavy hydrocarbon
zone using a
geothermal well can facilitate mobilization and recovery of the heavy
hydrocarbons. Various
implementations, aspects and applications of the technology are described in
further detail herein.
Date Recue/Date Received 2022-09-29
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10005 ] In some aspects, there is provided a system for recovering heavy
hydrocarbons from
a subsurface formation, the system comprising:
a geothermal well comprising:
a heat-receiving well section extending within a geothermal zone of the
formation
and being configured to be heated by geothermal heat in the geothermal zone
and
transmit heat upward; and
a heat-transmission well section extending from the heat-receiving well
section
and extending into at least a heavy hydrocarbon zone of the formation located
above the geothermal zone, the heat-transmission well section being configured
to receive heat from the heat-receiving well section and transmit heat into
the
heavy hydrocarbon zone to promote mobilization of the heavy hydrocarbons; and
a production well located in the heavy hydrocarbon zone and configured to
receive
mobilized heavy hydrocarbons for recovery to surface.
10006 ] In some aspects, the heavy hydrocarbons may include heavy
hydrocarbons, such as
heavy oil, and/or bitumen. The hydrocarbons could also include oil or other
hydrocarbon fluids.
10007 ] In some aspects, the geothermal well can include an elongated
component located
in a corresponding wellbore and composed of a heat conductive material, and
the heat is
transmitted upward from the heat-receiving well section by conduction.
10008 ] In some aspects, the geothermal well can include a supercritical
fluid located in the
heat-receiving well section and heat-transmission well section, and the heat
is transmitted upward
from the heat-receiving well section to the heat-transmission well section by
conduction.
10009 ] The geothermal well can include an insulated casing, which can be a
vacuum
insulated tubing casing.
10010 ] In some aspects, the geothermal well can further include an upper
well section that
extends from the heat-transmission well section to the surface.
Date Recue/Date Received 2022-09-29
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10011 1 The geothermal well can be configured to receive an injection fluid
that is injectable
downhole from the surface via the upper well section, and enters the heavy
hydrocarbon zone via
the heat-transmission well section. The injection fluid may be heated in the
heat-transmission
section and/or heat-receiving well section to form a heated fluid, and the
heated fluid is injected
into the heavy hydrocarbon zone via the heat-transmission well section. In
some aspects, the
injection fluid is not preheated at the surface. The injection fluid may
include a gas, a liquid, or a
mixture thereof. The gas can include steam or CO2, while the liquid can
include water.
10012 ] The geothermal well may be configured so that the injection fluid
is heated the heat-
receiving well section to form a heated fluid, the heated fluid being
circulated to the heat-
transmission well section and injected into the heavy hydrocarbon zone via the
heat-transmission
well section.
10013 ] The geothermal well may be configured to receive a first injection
fluid that is
injectable downhole from the surface via the upper well section, and is
transported to the heat-
receiving well section to form a heated first injection fluid, the heated
fluid being circulated to the
heat-transmission well section; and a second injection fluid that is heated in
the heat-transmission
to form a heated second injection fluid, and the heated second injection fluid
is injected into the
heavy hydrocarbon zone via the heat-transmission well section. The first
injection fluid may be a
supercritical fluid.
10014 ] In some aspects, the geothermal well may be configured such that
steam is
generated upon heating of the water in the heat-transmission well section, and
the steam is injected
into the heavy hydrocarbon zone from the heat-transmission well section.
10015 ] In some aspects, the heat-transmission well section includes a
tubular liner that
includes perforations for injection of the injection fluid into the heavy
hydrocarbon zone.
10016 ] The geothermal well may include at least one valve or packer
located in a downhole
region of the heat-transmission well section to prevent flow of the injection
fluid further downhole.
The at least one valve or packer may be located at a downhole end of the heat-
transmission well
section to prevent flow of the injection fluid into the heat-receiving well
section.
Date Recue/Date Received 2022-09-29
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10017 ] The geothermal well may also include at least one control valve
located at an uphole
region of the heat-transmission well section or in the upper well section to
control the injection
fluid entering the heat-transmission well section.
10018 ] In some aspects, the heat-receiving well section may be configured
to receive a hot
native fluid from the geothermal zone of the formation, and transport the hot
native fluid uphole
into the heat-transmitting well section. The hot native fluid may be injected
into the heavy
hydrocarbon zone via the heat-transmission well section. The hot native fluid
may include a gas,
a liquid, or a mixture thereof. The gas may include steam or CO2, whereas the
liquid may include
water.
10019 ] In some aspects, the geothermal well may be configured such that
lower pressures
that are present ascending up the geothermal well cause the water to flash to
form steam which is
injected into the heavy hydrocarbon zone via the heat-transmission well
section.
10020 ] The geothermal well may include at least one stop valve or packer
located in an
uphole region of the heat-receiving well section to prevent flow of the native
fluid further up the
geothermal well.
10021 ] The geothermal well may also include a flow control valve that is
located at an
uphole region of the heat-receiving well section and configured to control
flow of the hot native
fluid into the heat-transmission well section. The at least one flow control
valve may control the
amount of the native fluid entering the heat-transmission well section.
10022 ] In some aspects, the heat-receiving well section may be configured
to transmit the
heat by conduction to the heat-transmission well section, and the heat-
transmission well section is
configured to transmit the heat into the heavy hydrocarbon zone by conduction,
in the absence of
fluid injection into the heavy hydrocarbon zone.
10023 ] In some aspects, the heat-receiving well section may be configured
to prevent flow
of a native fluid from the geothermal zone of the formation uphole into the
heat-transmission well
section.
Date Recue/Date Received 2022-09-29
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10024 ] In some aspects, the heat-transmission well section may be
horizontal and overly
at least a portion of the production well. The heat-transmission well section
may also be parallel
with and vertically spaced apart from the production well.
10025 ] In some aspects, the heat-receiving well section may substantially
be perpendicular
with respect to the heat-transmission well section. The heat-receiving well
section may be
generally vertical. The heat-receiving well section may also be generally
inclined.
10026 ] In some aspects, the heavy hydrocarbon zone and the geothermal zone
are vertically
separated from each other by at least one barrier zone of the formation.
10027 ] In some aspects, the heat-receiving well section may have branched
well sections
or may be a linear well section.
10028 ] In some aspects, there may be a plurality of the geothermal wells
associated with
one or more production wells. A plurality of the production wells may also be
associated with the
geothermal well.
10029 ] In some aspects, there is provided a method for recovering heavy
hydrocarbons
from a subsurface formation, the method comprising:
heating a heavy hydrocarbon zone of the formation and mobilizing heavy
hydrocarbons
contained therein with geothermal heat obtained from a geothermal zone of the
formation,
wherein the geothermal heat is obtained by a geothermal well comprising:
a heat-receiving well section extending within the geothermal zone of the
formation, and
being configured to be heated by geothermal heat in the lower geothermal zone
and
transmit heat upward;
a heat-transmission well section extending from the heat-receiving well
section and
extending into at least the heavy hydrocarbon zone of the formation located
above the
geothermal zone, the heat-transmission well section being configured to
receive heat from
the heat-receiving well section and transmit heat into the heavy hydrocarbon
zone to
promote mobilization of the heavy hydrocarbons; and
Date Recue/Date Received 2022-09-29
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recovering the mobilized heavy hydrocarbons to surface.
10030 ] In some aspects, the heating and the recovering are performed
simultaneously; or
wherein the heating is performed as a pretreatment step prior to recovering
the mobilized heavy
hydrocarbons from the subsurface formation.
10031 ] In some aspects, the heating of the heavy hydrocarbon zone may be
performed by
conduction of the geothermal heat through the heat-receiving well section and
the heat-
transmission well section and into the heavy hydrocarbon zone in the absence
of fluid injection
into the geothermal well.
10032 ] In some aspects, the heating of the heavy hydrocarbon zone may be
performed by
conduction of the geothermal heat from the heat-receiving well section to the
heat-transmission
well section, and by downhole injection of an injection fluid that is heated
in the heat-transmission
well section and then injected into the heavy hydrocarbon zone.
10033 ] In some aspects, the heating of the heavy hydrocarbon zone may
include
introducing a circulation fluid downhole into the geothermal well, wherein the
circulation fluid is
circulated through the heat-receiving well section to be heated to form a
heated fluid, and then the
heated fluid is transported to the heat-transmission well section for
injection into the heavy
hydrocarbon zone or for indirect heating of the heavy hydrocarbon zone. The
circulation fluid may
include a gas, a liquid, or a mixture thereof. The gas may include steam or
CO2, whereas the liquid
may include water. In some aspects, steam may be generated as the heated fluid
upon heating of
the water in the heat-receiving well section, and the steam is injected into
the heavy hydrocarbon
zone from the heat-transmission well section.
10034 ] In some aspects, the heating of the heavy hydrocarbon zone may be
performed by
conduction of the geothermal heat from the heat-receiving well section to the
heat-transmission
well section, and by injection of a hot native fluid that is received from the
geothermal zone of the
formation through heat-receiving well section, transported uphole to the heat-
transmission well
section, and then injected into the heavy hydrocarbon zone. The native fluid
may include a gas, a
liquid, or a mixture thereof. The gas may include steam or CO2, whereas the
liquid may include
water.
Date Recue/Date Received 2022-09-29
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10035 ] In some aspects, lower pressures that are present ascending up the
geothermal well
cause the water to flash to form steam which is injected into the heavy
hydrocarbon zone via the
heat-transmission well section.
10036 ] In some aspects, the recovering of the mobilized heavy hydrocarbons
may be
performed by gravity drainage.
10037 ] In some aspects, there is provided a method for recovering
hydrocarbons from a
subsurface formation, the method comprising transferring geothermal heat from
a geothermal zone
of the formation to a hydrocarbon zone located above the geothermal zone by
conduction to
promote mobilization of the hydrocarbons for production thereof to surface.
The hydrocarbons
may include heavy hydrocarbons.
10038 ] In some aspects, there is provided a method for recovering
hydrocarbons from a
subsurface formation, the method comprising transferring geothermal heat from
a geothermal zone
of the formation to a hydrocarbon zone located above the geothermal zone
without transferring the
geothermal heat to surface to promote mobilization of the hydrocarbons for
production thereof to
the surface. The hydrocarbons may include heavy hydrocarbons.
10039 ] In some aspects, there is provided a method for heating and
recovering a fluid in a
subsurface formation, the method comprising:
heating a fluid-containing zone of the formation with geothermal heat obtained
from a
geothermal zone of the formation, wherein the geothermal heat is obtained by a
geothermal well comprising:
a heat-receiving well section extending within the geothermal zone of the
formation, and being configured to be heated by geothermal heat in the lower
geothermal zone and transmit heat upward;
a heat-transmission well section extending from the heat-receiving well
section and
extending into at least the fluid-containing zone of the formation located
above the
geothermal zone, the heat-transmission well section being configured to
receive
Date Recue/Date Received 2022-09-29
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heat from the heat-receiving well section and transmit heat into the fluid-
containing
zone to heat fluids contained therein; and
recovering heated fluid to surface.
10040 ] In some aspects, there is provided a system for recovering
hydrocarbons from a
subsurface formation, the system comprising:
a geothermal well comprising:
a heat-receiving well section extending within a geothermal zone of the
formation and being configured to be heated by geothermal heat in the
geothermal zone and transmit heat upward;
a heat-transmission well section extending from the heat-receiving well
section
and extending into at least a hydrocarbon zone of the formation located above
the geothermal zone, the heat-transmission well section being configured to
receive heat from the heat-receiving well section and transmit heat into the
hydrocarbon zone to promote mobilization of the hydrocarbons; and
a production well located in the hydrocarbon zone and configured to receive
mobilized hydrocarbons for recovery to surface.
10041 ] In some aspects, there is provided a method for recovering
hydrocarbons from a
subsurface formation, the method comprising:
heating a hydrocarbon zone of the formation and mobilizing hydrocarbons
contained
therein with geothermal heat obtained from a geothermal zone of the formation,
wherein the geothermal heat is obtained by a geothermal well comprising:
a heat-receiving well section extending within the geothermal zone of the
formation, and being configured to be heated by geothermal heat in the lower
geothermal zone and transmit heat upward;
Date Recue/Date Received 2022-09-29
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a heat-transmission well section extending from the heat-receiving well
section and
extending into at least the hydrocarbon zone of the formation located above
the
geothermal zone, the heat-transmission well section being configured to
receive
heat from the heat-receiving well section and transmit heat into the
hydrocarbon
zone to promote mobilization of the hydrocarbons; and
recovering the mobilized hydrocarbons to surface.
10042 ] In some aspects, there is provided a system for recovering heavy
hydrocarbons and
geothermal heat from a subsurface formation, the system comprising:
a geothermal well comprising:
a heat-receiving well section extending within a geothermal zone of the
formation and being configured to be heated by geothermal heat in the
geothermal zone and transmit heat upward;
a heat-transmission well section extending from the heat-receiving well
section
and extending into at least a heavy hydrocarbon zone of the formation located
above the geothermal zone, the heat-transmission well section being configured
to receive geothermal heat from the heat-receiving well section and transmit a
first portion of the geothermal heat into the heavy hydrocarbon zone to
promote
mobilization of the heavy hydrocarbons;
an upper well section extending from the heat-transmission well section to the
surface, the upper well section being configured to receive a second portion
of
the geothermal heat from the heat-transmission well section for recovery to
the
surface; and
a production well located in the heavy hydrocarbon zone and configured to
receive mobilized heavy hydrocarbons for recovery to the surface.
10043 ] The geothermal well may include an elongated component located in a
corresponding wellbore and composed of a heat conductive material, and the
geothermal heat is
transmitted upward from the heat-receiving well section by conduction.
Date Recue/Date Received 2022-09-29
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10044 ] The geothermal well may include a supercritical fluid located in
the heat-receiving
well section and heat-transmission well section, and the heat is transmitted
upward from the heat-
receiving well section to the heat-transmission well section by conduction.
10045 ] The geothermal well may include an insulated casing, which may be a
vacuum
insulated tubing casing.
10046 ] The geothermal well may be configured such that the heat-receiving
well section is
configured to receive a hot native fluid from the geothermal zone of the
formation, and transport
the hot native fluid uphole into the heat-transmission well section and to the
surface.
10047 ] The geothermal well may be configured such that a first portion of
the hot native
fluid is transported into the heat-transmission well section and injected into
the heavy hydrocarbon
zone; and a second portion of the hot native fluid is transported into the
heat-transmission well
section and further into the upper well section for recovery to the surface.
The hot native fluid may
include a gas, a liquid, or a mixture thereof. The gas may include steam or
CO2. The liquid may
include water.
10048 ] The geothermal well may be configured such that the second portion
of the hot
native fluid comprises steam that is used for generating electricity at or
just below the surface.
10049 ] The geothermal well may be configured such that the geothermal heat
recovered to
the surface is used for generating electricity and/or steam.
10050 ] In some aspects, there is provided a system for recovering
geothermal heat and/or
a hot native fluid from a subsurface formation, the system comprising:
a geothermal well comprising:
a heat-receiving well section extending within a geothermal zone of the
formation and being configured to transport the geothermal heat and/or hot
native fluid in the geothermal zone upward; and
an upper well section extending from the heat-receiving well section to the
surface, the upper well section being configured to receive the geothermal
heat
Date Recue/Date Received 2022-09-29
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and/or hot native fluid from the heat-receiving well section for recovery to
the
surface.
10051 ] The geothermal well may include an elongated component located in a
corresponding wellbore and composed of a heat conductive material, and the
geothermal heat is
transmitted upward from the heat-receiving well section by conduction.
10052 ] The geothermal well may include a supercritical fluid located in
the heat-receiving
well section and heat-transmission well section, and the heat is transmitted
upward from the heat-
receiving well section to the heat-transmission well section by conduction.
10053 ] The geothermal well may include an insulated casing, which may be a
vacuum
insulated tubing casing.
10054 ] The hot native fluid may include a gas, a liquid, or a mixture
thereof. The gas may
include steam or CO2. The liquid may include water..
10055 ] The geothermal well may be configured such that the hot native
fluid comprises
steam that is used for generating electricity at or just below the surface.
10056 ] The geothermal well may be configured such that the geothermal heat
recovered to
the surface is used for generating electricity and/or steam.
10057 ] In some aspects, there is provided a method for recovering
hydrocarbons,
geothermal heat, and/or hot native fluid from a subsurface formation, the
method comprising:
heating a hydrocarbon zone of the formation and mobilizing hydrocarbons
contained
therein with geothermal heat and/or hot native fluid obtained from a
geothermal zone
of the formation, wherein the geothermal heat and/or hot native fluid is
obtained by a
geothermal well comprising:
a heat-receiving well section extending within the geothermal zone of the
formation, and being configured to be heated by geothermal heat and/or hot
native
fluid in the lower geothermal zone and transmit heat upward;
Date Recue/Date Received 2022-09-29
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a heat-transmission well section extending from the heat-receiving well
section and
extending into at least the hydrocarbon zone of the formation located above
the
geothermal zone, the heat-transmission well section being configured to
receive
geothermal heat and/or hot native fluid from the heat-receiving well section
and
transmit a first portion of the geothermal heat and/or hot native fluid into
the
hydrocarbon zone to promote mobilization of the hydrocarbons;
an upper well section extending from the heat-transmission well section to the
surface, the upper well section being configured to receive a second portion
of the
geothermal heat and/or hot native fluid from the heat-transmission well
section for
recovery to the surface; and
recovering the mobilized hydrocarbons and the geothermal heat to the surface.
10058 ] In some aspects, there is provided a method for recovering
geothermal heat and/or
hot native fluid from a subsurface formation, the method comprising:
obtaining geothermal heat and/or hot native fluid contained within a
geothermal zone
of the subsurface formation, wherein the geothermal heat and/or hot native
fluid is
obtained by a geothermal well comprising:
a heat-receiving well section extending within the geothermal zone and being
configured to transport the geothermal heat and/or hot native fluid in the
geothermal zone upward; and
an upper well section extending from the heat-receiving well section to the
surface, the upper well section being configured to receive the geothermal
heat
and/or hot native fluid from the heat-receiving well section for recovery to
the
surface;
using the geothermal heat and/or hot native fluid at the surface.
10059 ] In some aspects, there is provided a method for recovering
geothermal heat and/or
hot native fluid from a subsurface formation, the method comprising:
Date Recue/Date Received 2022-09-29
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obtaining geothermal heat and/or hot native fluid contained within a
geothermal zone
of the formation, wherein the geothermal heat and/or hot native fluid is
obtained by an
abandoned well, and wherein the abandoned well is configured to receive the
geothermal heat and/or the hot native fluid from the geothermal zone; and
recovering at least a portion of the geothermal heat and/or at least a portion
of the hot
native fluid to the surface.
10060 ] In some aspects, at least a downhole portion of the abandoned well
is located in the
geothermal zone of the formation.
10061 ] In some aspects, the method further comprises drilling downhole
into the
abandoned well to extend the abandoned well and reach the geothermal zone of
the formation.
10062 ] In some aspects, the abandoned well receives an elongated component
composed
of a heat conductive material, and the geothermal heat is transmitted uphole
in the well by
conduction through the elongated component.
10063 ] In some aspects, the abandoned well comprises a supercritical
fluid, and the
geothermal heat is transmitted uphole in the well by conduction.
10064 ] In some aspects, the abandoned well comprises an insulated casing,
which may be
a vacuum insulated tubing casing.
10065 ] In some aspects, the abandoned well receives a hot native fluid
from the geothermal
zone of the formation, and transports the hot native fluid uphole in the well
to the surface. The hot
native fluid may include a gas, a liquid, or a mixture thereof. The gas may
include steam or CO2.
The liquid may include water..
10066 ] In some aspects, the abandoned well is an abandoned production well
or and
abandoned injection well.
10067 ] In some aspects, the hot native fluid comprises steam that is used
for generating
electricity at or just below the surface.
Date Recue/Date Received 2022-09-29
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10068 ] In some aspects, the geothermal heat recovered to the surface is
used for generating
electricity and/or steam.
10069 ] In some aspects, there is provided a use of geothermal heat
recovered by the system
defined herein or by the method defined herein, for generating electricity
and/or steam, or for
reinjection into a geothermal well for recovering heavy hydrocarbons from the
subsurface
formation and/or a second subsurface formation.
10070 ] In some aspects, there is provided a system for geothermally
heating and recovering
an injection fluid, the system comprising:
a geothermal well comprising:
a heat-receiving well section extending within a geothermal zone of a
subsurface formation and being configured to transport the injection fluid in
the
geothermal zone downward; and
an upper well section extending from the heat-receiving well section to the
surface, the upper well section being configured to receive an injection fluid
that
is injectable downhole from the surface via the upper well section;
wherein the geothermal well is configured so that the injection fluid is
heated in the
geothermal zone to form a geothermally-heated fluid and wherein the heat-
receiving well
section is configured to receive the geothermally-heated fluid for recovery to
the surface.
10071 ] In some aspects, there is provided a method for geothermally
heating and
recovering an injection fluid, the method comprising:
injecting an injection fluid into a geothermal well comprising:
a heat-receiving well section extending within a geothermal zone of a
subsurface formation and being configured to transport the injection fluid in
the
geothermal zone downward; and
Date Recue/Date Received 2022-09-29
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an upper well section extending from the heat-receiving well section to the
surface, the upper well section being configured receive the injection fluid
that
is injectable downhole from the surface via the upper well section;
wherein the geothermal well is configured so that the injection fluid is
heated in
the geothermal zone to form a geothermally-heated fluid and wherein the heat-
receiving well section is configured to receive the geothermally-heated fluid
for
recovery to the surface;
and
recovering the geothermally-heated fluid at the surface.
10072 ] In some aspects, there is provided a use of geothermally-heated
injection fluid
recovered by the system defined herein or by the method defined herein, for
generating electricity
and/or steam, or for reinjection into a geothermal well for recovering heavy
hydrocarbons from
the subsurface formation and/or a second subsurface formation.
BRIEF DESCRIPTION OF THE DRAWINGS
10073 ] For a better understanding of the aspects and implementations
described herein and
to show more clearly how they may be carried into effect, reference will now
be made, by way of
example only, to the accompanying drawings which show exemplary
implementations, and in
which:
10074 ] Fig. 1 is a side view schematic of a system for recovering heavy
hydrocarbons
according to one example implementation. The system comprises a geothermal
well comprising a
heat-receiving well section and a heat-transmitting well section, where the
geothermal well heats
the heavy hydrocarbons by conduction (wavy lines) of heat from a hot
geothermal zone up to the
heavy hydrocarbon zone. Heated heavy hydrocarbons are then recovered to the
surface via a
production well.
10075 ] Fig. 2 is a side view schematic of the system for recovering heavy
hydrocarbons
according to a second example implementation. The system comprises a
geothermal well
comprising a heat-receiving well section and a heat-transmitting well section,
where the
Date Recue/Date Received 2022-09-29
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geothermal well heats the heavy hydrocarbons by conduction of heat from a hot
geothermal zone
up to the heavy hydrocarbon zone, as well as by injection of a fluid (dashed
arrows; white arrows
represent colder fluid and black arrows represent heated fluid) from the
surface that is heated in
heat-transmitting well section and injected into the heavy hydrocarbon zone.
Heated heavy
hydrocarbons are then recovered to the surface via a production well.
10076 ] Fig. 3 is a side view schematic of the system for recovering heavy
hydrocarbons
according to a third example implementation. The system comprises a geothermal
well comprising
a heat-receiving well section and a heat-transmitting well section, where the
geothermal well heats
the heavy hydrocarbons by conduction of heat (solid arrows) from a hot
geothermal zone up to the
heavy hydrocarbon zone. In addition, a hot native fluid (dashed arrows) from
the hot geothermal
zone flows into the geothermal well and is transported from the heat-receiving
well section up to
the heat-transmission well section for injection into the heavy hydrocarbon
zone. Heated heavy
hydrocarbons are then recovered to the surface via a production well.
10077 ] Fig. 4 is a close-up side view schematic of the heat-receiving well
section,
according to one example implementation.
10078 ] Fig. 5 is a close-up side view schematic of the upper well
receiving section,
according to one example implementation.
10079 ] Fig. 6 is a close-up side view schematic of the heat-transmitting
well section,
according to one example implementation.
10080 ] Fig. 7 is a close-up side view schematic of the heat-transmitting
well section,
according to one example implementation.
10081 ] Fig. 8 is a side view schematic of the system of Figs. 1 to 3,
whereby the hot native
fluid (dashed arrows from the hot geothermal zone) from the hot geothermal
zone and injection of
a fluid (dashed arrows from the surface; white arrows represent colder fluid
and black arrows
represent heated fluid) from the surface is transported to the heat-
transmitting well section and
injected into the heavy hydrocarbon zone.
Date Recue/Date Received 2022-09-29
17
10082 ] Fig. 9 is a side view schematic of the system of Fig. 2 and 3,
whereby the hot native
fluid (dashed arrows from the hot geothermal zone) from the hot geothermal
zone and/or injection
of a fluid (dashed arrows from the surface; white arrows represent colder
fluid and black arrows
represent heated fluid) from the surface is transported to the heat-
transmitting well section and
injected into the heavy hydrocarbon zone, in the absence of conduction.
10083 ] Fig. 10 is a side view schematic of the system of Fig. 2, wherein
injection of a fluid
(dashed arrows from the surface; white arrows represent colder fluid and black
arrows represent
heated fluid) from the surface is transported to the heat-receiving well
section for heating in the
geothermal zone, circulated to the heat-transmission well section, and
injected into the heavy
hydrocarbon zone, in the absence of conduction.
10084 ] Fig. 11 is a side view schematic of the system of Fig. 1, wherein
the geothermal
well includes supercritical fluid (wavy arrows) that conducts geothermal heat
from the heat-
receiving well section to the heat-transmission well section, in the absence
of an elongated
component.
10085 ] Fig. 12 is a side view schematic of the system of Fig. 1, wherein
the geothermal
well includes supercritical fluid (wavy arrows) that conducts geothermal heat
and/or a hot native
fluid (dashed arrows from the hot geothermal zone) from the heat-receiving
well section to the
heat-transmission well section, in the absence of an elongated component. Hot
native fluid is then
injected into the hydrocarbon zone via the heat-transmission well section.
10086 ] Fig. 13 is a side view schematic of the system of Fig. 2, wherein
the geothermal
well includes supercritical fluid (wavy arrows) that conducts geothermal heat
from the heat-
receiving well section to the heat-transmission well section, in the absence
of an elongated
component. Injection of an injection fluid (dashed arrows from the surface;
white arrows represent
colder fluid and black arrows represent heated fluid) from the surface is
transported into the heat-
transmission well section to be heated and injected into the heavy hydrocarbon
zone.
10087 ] Fig. 14 is a side view schematic of the system of Fig. 2, wherein
injection of a
supercritical fluid (wavy arrows) from the surface is transported to the heat-
receiving well section
for heating in the geothermal zone, circulated to the heat-transmission well
section, in the absence
Date Recue/Date Received 2022-09-29
18
of an elongated component. Injection of another fluid (dashed arrows from the
surface; white
arrows represent colder fluid and black arrows represent heated fluid) from
the surface is
transported into the heat-transmission well section to be heated by the
circulating supercritical
fluid and injected into the heavy hydrocarbon zone.
10088 ] Fig. 15 is a side view schematic of the system of Fig. 1 and 3
whereby geothermal
heat (solid arrows) and/or hot native fluid (dashed arrows) from the hot
geothermal zone up is
further transported to the surface.
10089 ] Fig. 16 is a side view schematic of the system of Fig. 12, whereby
supercritical
fluid (wavy arrows) and/or hot native fluid (dashed arrows) from the hot
geothermal zone up is
further transported to the surface, in the presence of conduction with a
supercritical fluid (wavy
arrows),.
10090 ] Fig. 17 is a side view schematic of the system for recovering
geothermal heat (solid
arrows) and/or hot native fluid (dashed arrows) from a subsurface formation,
in the presence or
absence of conduction with an elongated component, using a geothermal well or
an abandoned
well.
10091 ] Fig. 18 is a side view schematic of the system for recovering
geothermal heat and/or
hot native fluid (dashed arrows) from a subsurface formation, in the presence
of conduction with
a supercritical fluid (wavy arrows), using a geothermal well or an abandoned
well.
10092 ] Fig. 19 is a side view schematic of the system for recovering
geothermally-heated
injection fluid from a subsurface formation, wherein injection of a fluid
(dashed arrows from the
surface; white arrows represent colder fluid and black arrows represent heated
fluid) from the
surface is transported to the heat-receiving well section for heating in the
geothermal zone,
circulated to the heat-transmission well section, and recovered to the
surface, using a geothermal
well or an abandoned well.
10093 ] It will be appreciated that for simplicity and clarity of
illustration, elements shown
in the figures have not necessarily been drawn to scale. For example, the
dimensions of some of
the elements may be exaggerated relative to other elements for clarity.
Nevertheless, for disclosure
Date Recue/Date Received 2022-09-29
19
purposes, it should be understood that the relative proportions of the various
elements as shown in
the figures are disclosed.
DETAILED DESCRIPTION
10094 ] The present description relates to systems and methods for
recovering heavy
hydrocarbons from a subsurface formation, as shown for example in Figs. 1-4,
as well as systems
and methods for retrieving heat from a subterranean formation and using the
heat at surface and/or
in a subterranean zone.
10095 ] In some implementations, the systems and methods described herein
leverage the
use of a geothermal well to obtain geothermal heat from a low zone of the
formation and transport
that heat up to a heavy hydrocarbon zone to heat and mobilize the hydrocarbons
to facilitate
recovery. The geothermal heat can be sent directly from the geothermal zone to
the heavy
hydrocarbon zone by conduction via completion equipment in the well and/or by
allowing hot
native fluid to flow up through the well for injection into the heavy
hydrocarbon zone. Optionally,
a fluid can be injected from surface and can be heated by the geothermal heat
and injected into
the reservoir.
10096 ] More particularly, the system can include a geothermal well that
brings heat from
the hot geothermal zone up to the heavy hydrocarbon zone for heating the heavy
hydrocarbons,
thereby reducing the viscosity of the heavy hydrocarbons for facilitated
recovery to the surface
by a nearby production well. The systems and methods described herein harness
geothermal heat
for directly heating hydrocarbons, and therefore provide enhancements in terms
of efficiency and
environmental sustainability.
10097 ] Referring now to Figs. 1 to 4, the present technology relates to a
system 10 for
recovering heavy hydrocarbons 12 from a subsurface formation. The system 10
includes a
geothermal well 14 that includes a heat-receiving well section 16 and a heat-
transmission well
section 18, and the system 10 also includes a production well 20. The heat-
receiving well 16
section extends within a geothermal zone 22 of the formation and is configured
to be heated by
geothermal heat in the geothermal zone 22 and to transmit the heat upward. The
heat-transmission
well section 18 extends from the heat-receiving well section 16 into at least
a heavy hydrocarbon
Date Recue/Date Received 2022-09-29
20
zone 24 of the formation located above the geothermal zone 22. The heat-
transmission well
section 18 is configured to receive heat from the heat-receiving well section
16 and to transmit
the heat into the heavy hydrocarbon zone 24 to promote mobilization of the
heavy hydrocarbons
12. The production well 20 is located in the heavy hydrocarbon zone 24 and is
configured to
receive mobilized heavy hydrocarbons 12 for recovery to the surface 26.
10098 ] As used herein, the term "hydrocarbons" may refer to any
hydrocarbon that is
present in a subsurface formation for recovery to the surface. The
hydrocarbons may in include
"heavy" hydrocarbons having a relatively high viscosity that would create
difficulties for in situ
recovery. Heavy hydrocarbons may include heavy oil, crude oil and bitumen, for
example.
Hydrocarbons may be localized in subsurface formations termed "hydrocarbon
zones" or
reservoirs. In some cases, heavy hydrocarbons have a low API (American
Petroleum Institute)
gravity. In some cases, the heavy hydrocarbons have an API gravity that is
lower than 30, 25, 20,
15, or 10. The heavy hydrocarbons can be recovered as oil-water emulsions, due
to native water
or injected water or steam. It is noted that the present technology may be
useful for the recovery
and/or production of various hydrocarbon fluids, including light crude oil,
shale oil, or vapour
phase hydrocarbons such as natural gas, where geothermal heating can provide
one or more
benefits. It is also possible to apply the techniques described herein to heat
other types of fluids
that are present in formations, such as water, brine, and the like.
10099 ] As used herein, the terms "subsurface formation", "underground
reservoir", and
"subterranean zone" may be used interchangeably. The subsurface formations
described herein
may be localized offshore or onshore and at any depth. Subsurface formations
may include
hydrocarbons and hydrocarbon zones. Furthermore, subsurface formations may
include
geothermal zones containing geothermal heat.
100100 ] As used herein, the term "surface" may refer to the uppermost
level of land (ground)
or sea, or to a region just below the surface (i.e., near surface).
100101 ] As used herein, the term "supercritical fluid" may refer to a
single or a mixture of
different fluids.
Date Recue/Date Received 2022-09-29
21
100102 ] As used herein, the term "mobilized" refers to hydrocarbons that
have a reduced
viscosity for facilitated recovery. Heating, for example, may be one method
for reducing the
viscosity of hydrocarbons and promoting their mobilization. In some
implementations, heating
hydrocarbons to at least 100 C may be sufficient for promoting mobilization.
Optimal temperature
ranges for mobilization may be at least within 150 C to 300 C, however, in
areas of higher
pressure, a lower temperature (<100 C) may be sufficient to heat and mobilize
the hydrocarbons.
In some implementations, the resulting viscosity of mobilized hydrocarbons is
preferably less than
about 1000 cP (centipoise), less than about 750 cP, less than about 500 cP,
less than about 250 cP,
less than about 100 cP, or less than about 50 cP.
100103 ] The subsurface formations including the heavy hydrocarbon zones 24
may be
located at various distances from a geothermal zone 22, and may be separated
by one or more
barriers. Barrier layers may include a low-permeability stratum in the
formation, and may be
formed of shale or mud, for example. The geothermal well 14 may be configured
to increase or
decrease the length of the heat-receiving well section 16 and/or the heat-
transmission well section
18 depending on the position of the heavy hydrocarbon zone 24 with respect to
the geothermal
zone 22. In some cases, the heavy hydrocarbon zone 24 and the geothermal zone
22 are vertically
separated from each other. Alternatively, the heavy hydrocarbon zone 24 and
the geothermal zone
22 are horizontally separated from each other.
100104 ] In some implementations, the heat-receiving well section 16 is
generally
perpendicular with respect to the heat-transmission well section 18,
especially when the heat-
transmission well section 18 is generally horizontal and the heat-receiving
well section 16 is
generally vertical. The heat-receiving well section 16 may be generally
vertical or generally
inclined, horizontal, or directional. In some implementations, the heat-
receiving well section 16
has branched well sections or is an unbranched well section.
100105 ] In some implementations, the heat-transmission well section 18 is
horizontal and
overlies at least a portion of the production well 20. In some cases, the heat-
transmission well 18
section is parallel with and vertically spaced apart from the production well
20, and forms a well
pair configuration with the production well 20. The heat-transmitting well
section 18 may also
have branched well sections or may be an unbranched well section. While the
well pair
Date Recue/Date Received 2022-09-29
22
confirmation is shown in the figures, it is also noted that the heat-
transmission well section 18 can
be located above one or more production wells 20 and oriented at various
angles rather than being
directly above and parallel with the production well 20.
100106 ] In some implementations, the geothermal well 14 includes an upper
well section 28
that extends from the heat-transmission well section 18 to the surface 26. The
upper well section
28 is formed during the initial drilling of the geothermal well 14 and may
simply be kept as a
wellbore access. In some cases, the upper well section 28 is used to inject an
injection fluid 32
downhole into the heat-transmitting well section 16, as will be described in
further detail below.
100107 ] In some implementations, the system includes a plurality of
geothermal wells 14
associated with one or more production wells 20. The geothermal wells 14 can
be provided in
various arrangements and patterns with respect to each other and with respect
to the production
wells 20. The system may include a combination of different geothermal wells,
as shown by
different implementations herein, associated with one or more production wells
20. For example,
one geothermal well 14 can be configured for fluid injection, while another
geothermal well 14
can be configured to transfer geothermal heat by conduction without fluid
injection. In addition,
there may be a plurality of production wells associated with a geothermal
well. Finally, the
systems, methods, or geothermal wells described herein may be partially or
completely combined
with existing in situ recovery systems and methods for recovering heavy
hydrocarbons, such as
but not limited to the SAGD process. For example, one or more SAGD well pairs
could be located
close to and associated with one or more of the geothermal wells 14.
First Implementation
100108 ] Fig. 1 illustrates the system 10 that includes the geothermal well
14 which heats
the heavy hydrocarbons 12 by conduction of heat from the hot geothermal zone
22 to the heavy
hydrocarbon zone 24 where fluid does not flow into the heat-transmission
section 18 from the
surface or from the heat-receiving section 16.
100109 ] According to this example implementation, the geothermal well 14
includes an
elongated component 30 located in the wellbore of the geothermal well and
composed of a heat
conductive material, and the heat is transmitted upward (or "uphole" as
depicted by the arrows in
Date Recue/Date Received 2022-09-29
23
Fig. 1) from the heat-receiving well section 16 by conduction. The elongated
component 30 may
be, but is not limited to, a rod, a cable or a tubular. The elongated
component 30 can be constructed
so as to promote heating from the geothermal zone, conducting heat up to the
heat-transmission
section 18, and then releasing the heat into the heavy hydrocarbon zone 24.
The elongated
component 30 can have an outer surface that is in direct contact with the
inner wall of the wellbore
at locations where heat is transported into the hydrocarbon zone 24, and it
can be insulated from
the formation in locations where heat transmission to the outer formations is
to be minimized (e.g.,
through barrier zones or any zones that are in between the geothermal zone and
the heavy
hydrocarbon zone). The heat conductive material may be a metal, such as to
steel. The elongated
component 30 may extend between a lower part of the heat-receiving well
section 16 to an upper
part of the heat-transmitting well section 18, although it can have various
dimensions and
constructions depending on the application. Heat released by the heat-
transmitting well section 18
into the reservoir is depicted as wavy lines in Fig. 1.
100110 ] The geothermal well 14 may further include an insulated casing.
The insulating
casing may enclose the elongated component 30 to prevent heat loss in certain
locations. The
insulated casing may be a vacuum insulated tubing (VIT) casing. The insulated
casing surface may
therefore be in direct contact with the inner wall of the wellbore at
locations where heat is
transported into the hydrocarbon zone 24, to minimize heat loss from the
wellbore to the outer
formation. The insulation can thus be provided in between the heat-receiving
and heat-releasing
sections of the geothermal well.
100111 ] The geothermal well 14 also includes the upper well section 28
that extends from
the heat-transmission well section 18 to the surface 26. The upper well
section 28 is formed during
drilling and may be completed in various ways depending on the desired use.
For example, for this
example implementations, the upper well section 28 may simply be a wellbore
access (e.g., for
inspection, maintenance or measurements) and thus is not equipped for
injection or production.
The upper well section 28 could also be completed so that little to no
geothermal heat or fluid can
travels up from the heat-transmission well section 18, and therefore could be
provided with
appropriate equipment for this purpose.
Second Implementation
Date Recue/Date Received 2022-09-29
24
100112 ] Fig. 2 illustrates the system 10 which includes the geothermal
well 14 which heats
the heavy hydrocarbons 12 by conduction of heat from the hot geothermal zone
22 to the heavy
hydrocarbon zone 24, and in this sense is similar to the system 10 according
to the first
implementation, but it also involves providing an injection fluid 32 from the
surface 26. The
injection fluid 32 is provided from the surface 26 downhole and into the heat-
transmitting well 18
section. The injection fluid 32 is heated by the heat-transmitting well 18
section, which has
received geothermal heat, and is injected into the heavy hydrocarbon zone 24.
This implementation
therefore includes geothermal heating as well as fluid injection from the
surface to help mobilize
the heavy hydrocarbons 12.
100113 ] According to this example implementation, the injection fluid 32
is introduced via
the upper well section 28 and flows down into the heat-transmitting well
section 18. The upper
well section 28 may therefore be coupled to injection equipment at surface 26
which can be
configured depending on the type and state of the injection fluid (e.g.,
vapor, liquid, heated,
ambient). The injection fluid 32 is then heated by the heat-transmitting well
section 18, which is
heated geothermally by conduction as described herein. The heated injection
fluid 32 is then
injected into the heavy hydrocarbon zone 24 to help mobilize the heavy
hydrocarbons 12. The
heavy hydrocarbons 12 may therefore be heated by conduction of geothermal heat
from the heat-
transmitting well section 18 into the hydrocarbon zone, as well as by contact
with the heated
injection fluid 32 entering the hydrocarbon zone 24. The injection fluid 32
can help mobilize the
heavy hydrocarbons by heating and also be other mechanisms as some injection
fluids can mix
with the hydrocarbons and help reduce viscosity.
100114 ] For this implementation, the heat-transmitting well section 18 is
configured to
allow the injection fluid to flow into the heavy hydrocarbon zone 24, and thus
provides fluid
communication between the wellbore and the surrounding reservoir. For
instance, the heat-
transmitting well section 18 may include perforations 34 for releasing the
heated injection fluid 32
into the heavy hydrocarbon zone 24, as shown in Fig. 6. The perforations 34
can be provided
through a tubular liner that facilitates transmission of the geothermal heat.
The heat-transmitting
well section 18 may include flow control devices 35 or other completion
systems to enable
injection of the heated injection fluid 32 into the heavy hydrocarbon zone 24,
as shown
schematically in Fig. 7. The heat-transmitting well section 18 may include a
steel tubing that is
Date Recue/Date Received 2022-09-29
25
perforated for injection of the injection fluid 32. The injection fluid 32 can
be delivered from
surface using a pump or a compressor, for example, depending on the type of
injection fluid
introduced into the geothermal well.
100115 ] The injection fluid 32 may include a gas, liquid, or a mixture of
gas and liquid. The
gas may include steam or CO2. The liquid may include water. In some
implementations, the
injection fluid 32 is not preheated prior to downhole injection. In some
cases, the injection fluid
32 is a liquid (e.g., liquid comprising water) which is introduced as a liquid
and is heated in the
heat-transmitting well section 18 and is thus converted partially or
completely into a gas (e.g.,
steam) which is injected into the heavy hydrocarbon zone 24. This downhole
vaporization of the
injection fluid is enabled by the geothermal heat in the heat-transmitting
well section 18.
Alternatively, the injection fluid can be in liquid phase when introduced into
the geothermal well
and also when injected into the reservoir.
100116 ] When fluid is injected into the reservoir, it can form a mixture
with the mobilized
heavy hydrocarbons 12, which is then recovered as the production fluid. The
production fluid can
include hydrocarbons, injection fluid as well as other native fluids such as
water and light gases.
The production fluid is treated at surface. Heavy hydrocarbons 12 may be
separated from the other
components of the production fluid by various methods, such as by using
separators (e.g., gas
separator, oil/water separator, vapor/liquid separators, etc.). In some
implementations, the
produced water and/or gas/CO2 that is separated from the hydrocarbons may be
treated and reused
as part of the injection fluid 32. In general, the production fluid can be
treated to remove the
injection fluid for reuse in the system 10.
100117 ] In the second implementation, the geothermal well 14 can be
equipped to allow the
injection fluid to pass from the surface, into the heat-transmission well
section, and into the
reservoir without flowing further down the geothermal well 14. For example,
the geothermal well
can have a packer, valve or another device that prevents fluid flow from the
heat-transmission well
section 18 down into the heat-receiving well section 16. The flow prevention
device can be
deployed at a downhole end of the heat-transmission well section 16, for
example. Examples of
such a packer 40 and valve 38 are schematically illustrated in this
arrangement in Fig. 6.
Third Implementation
Date Recue/Date Received 2022-09-29
26
100118 ] Fig. 3 illustrates the system 10 which includes the geothermal
well 14 that heats the
heavy hydrocarbons 12 by conduction of heat from the hot geothermal zone 22 to
the heavy
hydrocarbon zone 24, and in this sense is similar to the system 10 according
to the first
implementation, but it also involves allowing a hot native fluid to flow from
the geothermal zone
22 through the geothermal well 14 and into the heavy hydrocarbon zone 24. The
hot native fluid
36 is obtained from the hot geothermal zone 22 and is transported uphole from
the heat-receiving
well section 16 into the heat-transmission well section 18 for injection into
the heavy hydrocarbon
zone 24.
100119 ] According to this example implementation, the hot native fluid 36
is fluid that is
originally present in hot geothermal zone 22. The heat-receiving well section
16 may comprise a
fluid inlet 41 (see Fig. 4) that receives the hot native fluid 36 from the hot
geothermal zone 22 and
due to pressure differential the hot native fluid 36 flows up to the heat-
transmitting well section
18. The fluid inlet 41 could be configured to be operable between an open
position and a closed
position to control whether the hot native fluid can enter the geothermal well
14. The fluid inlet 41
may be configured to work independently or in conjunction with the elongated
component 30 (heat
conductive material). The native fluid is at a higher pressure compared to the
heat-transmitting
well section 18 and thus the heat-receiving well section 16 provides a conduit
for passage of the
native fluid to the lower pressure region. The hot native fluid 36 may then be
injected into the
heavy hydrocarbon zone 24 via the perforations 34 or other flow control
devices 35of the heat-
transmitting well section 18. The heavy hydrocarbons 12 may therefore be
heated by conduction
of geothermal heat via the heat-transmitting well 18 section, and by injecting
the hot native
geothermal fluid 36 that is transported uphole into the heat-transmitting well
section 18.
100120 ] The hot native fluid 36 may include gas, liquid, or a mixture of
gas and liquid,
depending on the fluids native to the particular geological formation. Due to
lower pressures that
are present ascending up the geothermal well 14, the hot native fluid 36,
which may begin as a
liquid (e.g., water), may flash to form a gas (e.g., steam) which is injected
into the heavy
hydrocarbon zone 24 via the heat-transmission well section 18. The hot native
fluid 36 may include
steam from its initial phase within the hot geothermal zone 22 and be injected
as steam and/or hot
water in the heat-transmission well section 18. In some instances, the hot
native fluid 36 is kept
Date Recue/Date Received 2022-09-29
27
hot or is further heated by simultaneous conduction of geothermal heat in the
heat-receiving well
section 16 and heat-transmitting well section 18, as described in the first
implementation.
100121 ] When native fluid is allowed to flow up and into the hydrocarbon
zone, it can form
a mixture with the mobilized heavy hydrocarbons 12, which is then recovered as
the production
fluid. The production fluid can include hydrocarbons, native fluid from the
geothermal zone, as
well as native fluids from the hydrocarbon zone. The production fluid is
treated at surface. Heavy
hydrocarbons 12 may be separated from the other components of the production
fluid by various
methods, such as by using separators (e.g., gas separator, oil/water
separator, vapor/liquid
separators, etc.). In some implementations, the produced water and/or gas/CO2
that is separated
from the hydrocarbons may be treated and disposed of or used as injection
fluid in another well.
100122 ] In the third implementation, the geothermal well 14 can be
equipped to allow the
hot native fluid to pass from the geothermal zone, up through the heat-
receiving well section, into
the heat-transmission well section, and then into the reservoir without
flowing further up the
geothermal well 14. For example, the geothermal well can have an uphole packer
40a, an uphole
valve 38a or another device that prevents fluid flow from the heat-
transmission well section 18 up
the upper section of the geothermal well. The flow prevention device can be
deployed at an uphole
end of the heat-transmission well section 16, for example. Examples of such a
packer 40a and
valve 38a are schematically illustrated in this arrangement in Fig. 7.
Variant implementations
100123 ] While three example implementations have been described above, it
is noted that
one or more of the implementations can be used over time for a given system.
For example, a
geothermal well 14 could be initially operated according to the first
implementation with no fluid
injection from the surface or the geothermal zone, and then the geothermal
well could be
subsequently operated according to the second or third implementation by allow
the appropriate
fluid flow and injection. For instance, the geothermal well could be equipped
with valves that
could be operated manually or remotely in an open or closed position to allow
fluid to flow from
surface or from the geothermal zone into the heat-transmission well section
and then into the
hydrocarbon zone. The geothermal well could also be recompleted to switch
operation to another
implementation.
Date Recue/Date Received 2022-09-29
28
100124 ] It is also possible for a given geothermal well to switch
operation between the
second and third implementations. For instance, referring to Figs. 4-7, the
geothermal well 14
could be operated with fluid injection from the surface where the uphole valve
38a is open and the
downhole valve 38 is closed; and then the operating mode could be switched by
ceasing fluid
injection from the surface, closing the uphole valve 38a, opening the downhole
valve 38, and
opening the fluid inlet 41 to allow native fluid flow into the geothermal well
14. It may be of
interest to begin the hydrocarbon recovery process using the third
implementations to leverage the
hot native fluids present in the geothermal zone, and then if or when the hot
native fluids become
depleted the process can switch to fluid injection from the surface. In this
manner, the operating
mode of the geothermal well 14 could be modified between the first, second and
third
implementations, if desired.
100125 ] In addition, the systems according to the first, second and third
implementations
may be used alone or in combination for heating and/or recovery heavy
hydrocarbons. For
example, Fig. 8 describes a combination of the systems according to the first,
second and third
implementations, whereby geothermal heat is transmitted by conduction (with
the elongated
component 30) and transmission of a hot native fluid 36, and whereby an
injection fluid 32 is
provided from the surface 26. In some cases, for both the hot native fluid 36
and the injection fluid
32 to be injected into the hydrocarbon zone 24 by the heat-transmission well
section, pressures in
the heat-receiving well section 16/geothermal zone 22 and upper well section
28 must be higher
than the pressure in the heat-transmission well section 18/hydrocarbon zone
24.
100126 ] Furthermore, Fig. 9 generally discloses systems in which the
geothermal well is
configured to provide geothermal heat to a target subterranean zone (e.g.,
hydrocarbon zone 24),
via a hot native fluid 36 and/or injection fluid 32, in the absence of
conduction. The geothermal
well 14, therefore, could be configured without an elongated component for
heat conduction. The
hot native fluid 36 (e.g., air or steam) may travel from the heat-receiving
well section 16 to the
heat-transmission well section 18 to be injected into the subterranean zone,
such as for
mobilization of the hydrocarbons 12. Similarly, the injection fluid 32, which
may or may not be
pre-heated, may flow into the heat-transmission well section 18 for injection
into the subterranean
zone. In some cases, the injection fluid 32 is heated downhole in the
subterranean zone. For
Example, in scenarios where an injection fluid 32 is provided for injection
into the hydrocarbon
Date Recue/Date Received 2022-09-29
29
zone 24 in the absence of conduction or hot native fluid 36, the injection
fluid 32 may be
transported downhole into the heat-receiving well section 16 to be heated by
the geothermal zone
22, and subsequently circulated to the heat-transmission well section 18 for
injection (Fig. 10). In
some cases, the injection fluid 32 is released into the hot geothermal zone
22, and is heated and
recovered by the heat-receiving well section 16 (Fig. 10).
100127 ] In some scenarios, in the absence of an elongated component 30,
supercritical fluid
42 may be used to conduct geothermal heat and/or hot native fluid in the
geothermal well 14, such
as in the systems of Fig. 11-14. The heat-receiving 16 and heat-transmission
18 well sections of
the geothermal well 14 may be filled with the supercritical fluid 42 to
conduct geothermal heat
from the heat-receiving well section 16 to the heat-transmission well section
18 (Fig. 11). A hot
native fluid 36 may be transported from the heat-receiving well section 16 to
the heat-transmission
well section 18 for injection into the hydrocarbon zone (Fig. 12). In some
scenarios, an injection
fluid 32 from the surface 26 may then be injected and transported into a
reservoir within the heat-
transmission well section 18 that is surrounded by the supercritical fluid 42
to be heated, and then
injected into the hydrocarbon zone 24 for mobilization of the hydrocarbons 18,
as described in Fig.
13. In some scenarios, the supercritical fluid 42 may be circulated in the
geothermal well for
heating the injection fluid 32. For example, described in Fig. 14 is a system
10, wherein injection
of the supercritical fluid 42 from the surface 26 is transported to the heat-
receiving well section 16
for heating in the geothermal zone, and is then circulated to the heat-
transmission well section 18.
Furthermore, injection of the injection fluid 32 from the surface 26,
optionally in a separate
compaiiment than the supercritical fluid 42, is transported into the heat-
transmission well section
to be heated by the circulating supercritical fluid 42 and is injected into
the hydrocarbon zone 24
for mobilization of hydrocarbons 12.
100128 ] The systems described herein may also be used alone or in
combination with other
conventional systems used for heating and/or recovery of heavy hydrocarbons.
Preferably, the
systems described herein do not utilize surface boilers or steam as an
injection fluid. The systems
described herein preferably minimize the use of non-renewable energy sources
for heating and/or
recovering heavy hydrocarbons.
Date Recue/Date Received 2022-09-29
30
100129 ] In some cases, the system 10 according to the first implementation
is used alone.
Therefore, the heat-receiving well section 16 is configured to transmit the
heat by conduction to
the heat-transmission well section 18, and the heat-transmission well section
18 is configured to
transmit the heat into the heavy hydrocarbon zone 24 by conduction, in the
absence of fluid
injection (either of hot native fluid 36 or injection fluid 32) into the
geothermal well 14 and the
heavy hydrocarbon zone 24.
100130 ] As mentioned above, the geothermal well 14 may include one more
valves and/or
packers, or other completion devices, to control uphole or downhole flow of
fluids. The one or
more valves and/or packers may be located at various points of the heat-
receiving well section 16,
heat-transmitting well section 18, and/or the upper well section 28, as shown
in Figs. 4-7.
100131 ] The geothermal well 14 may include at least one downhole valve 38
or packer 40
located in a downhole region of the heat-transmission well section 18 to
prevent flow of the
injection fluid 32 further downhole. The at least one downhole valve 38 or
packer 40 may be
located at a downhole end of the heat-transmission well section 18 to prevent
flow of the injection
fluid 32 into the heat-receiving well section 16. It is also possible to
provide multiple downhole
isolation devices, such as valves or packers, at various locations along the
heat-transmission well
section 18 and/or the heat-receiving well section 18, and to operate the
downhole isolation devices
to achieve desired fluid injection effects.
100132 ] The geothermal well 14 may include at least one control valve or
uphole valve 38a
located at an uphole region of the heat-transmission well section 18 or in the
upper well section
28. The control valve 38a can be configured and operated to control the
injection fluid 32 entering
the heat-transmission well section 18. Control of the injection fluid can also
be achieved using the
surface equipment to control injection rate or pressure of the fluid.
100133 ] The downhole and/or uphole valves 38/38a or the downhole and/or
uphole packers
40/40a can be configured to prevent fluid flow further up the geothermal well
14, which may be
desired to stop transfer of heat and/or hot native fluid 36 from the heat-
receiving well section 16
or heat-transmitting well section 18 further uphole or for well control
purposes. The
downhole/uphole valves 38/38a and/or the downhole/uphole packers 40/40a can be
located in
various parts of the heat-transmission well section 18, as shown in Figs. 6
and 7 for example.
Date Recue/Date Received 2022-09-29
31
100134 ] The geothermal well 14 may include a fluid circulation system that
allows fluid to
circulate without being injected into the reservoir. For example, the
geothermal well may be
configured such that hot circulation fluid is circulated from the surface down
into the heat-
transmission well section 18 to provide additional heat to the reservoir. The
circulation fluid could
be steam, but since the steam is not injected into the reservoir the
condensate does not require
substantial water treatment before being reused to generate additional steam.
It is also possible to
configure the fluid circulation system to receive the hot native fluid and
allow it pass up and
through the heat-transmission well section 18 without being injected into the
reservoir.
100135 ] The downhole and/or uphole valves 38/38a or the downhole and/or
uphole packers
40/40a can also be configured to prevent hot native fluid 36 backflow or
injection fluid 32 flow
downhole into the geothermal well 14. This may be desired to stop transfer of
heat and/or fluid
from the heat receiving well section 16 or heat-transmitting well section 18
further downhole, or
for well control purposes. The downhole/uphole valves 38/38a and/or the
downhole/uphole
packers 40/40a can be located in various parts of the heat-receiving well
section 16 or the heat-
transmission well section 18, as shown in Figs. 5-7 for example.
Methods for heating and recovering heavy hydrocarbons
100136 ] According to another general aspect of the technology, there is
described a method
for heating and/or recovering heavy hydrocarbons 12 from an underground
reservoir.
100137 ] According to another general aspect of the invention, there is
described a method
for recovering heavy hydrocarbons 12 from a subsurface formation, the method
comprising
transferring geothermal heat from a geothermal zone 22 of the formation to a
heavy hydrocarbon
zone 24 located above the geothermal zone 22 by conduction to promote
mobilization of the heavy
hydrocarbons 12 for recovery thereof to surface 26.
100138 ] According to another general aspect of the invention, there is
described a method
for recovering heavy hydrocarbons 12 from a subsurface formation, the method
comprising
transferring geothermal heat from a geothermal zone 22 of the formation to a
heavy hydrocarbon
zone 24 located above the geothermal zone 22 without transferring the
geothermal heat to surface
26 to promote mobilization of the heavy hydrocarbons 12 for recovery thereof
to the surface 26.
Date Recue/Date Received 2022-09-29
32
100139 ] According to one example implementation, there is described a
method for
recovering heavy hydrocarbons 12 from a subsurface formation, wherein the
method includes
heating a heavy hydrocarbon zone 24 of the formation and mobilizing heavy
hydrocarbons 12
contained therein with geothermal heat obtained from a geothermal zone 22 of
the formation,
wherein the geothermal heat is obtained by a geothermal well 14. The
geothermal well 14 includes
a heat-receiving well section 16 extending within the geothermal zone 22 of
the formation, and is
configured to be heated by geothermal heat in the lower geothermal zone 22 and
transmit heat
upward. The geothermal well 14 also includes a heat-transmission well section
18 extending from
the heat-receiving well section 16 and extending into at least the heavy
hydrocarbon zone 24 of
the formation located above the geothermal zone 22, the heat-transmission well
section 18 being
configured to receive heat from the heat-receiving well section 16 and
transmit heat into the heavy
hydrocarbon zone 24 to promote mobilization of the heavy hydrocarbons12. The
method further
includes recovering the mobilized heavy hydrocarbons 12 to surface 26.
100140 ] The methods described herein may utilize the systems 10 or
geothermal wells 14
according to the example implementations described herein, either alone or in
combination.
100141 ] Recovering mobilized heavy hydrocarbons 12 may involve the use of
one or more
production wells 20 located nearby the geothermal wells 14. In some cases, the
recovering of the
mobilized heavy hydrocarbons 12 is performed by gravity drainage. In some
cases, the heating
and the recovering are performed simultaneously. Alternatively, the heating is
performed as a
pretreatment step prior to recovering the mobilized heavy hydrocarbons 12 from
the subsurface
formation. The geothermal heating methods can be used for starting up a well
pair or a well to be
used for injection. The geothermal heating methods can be used where the
geothermal well
operates in conjunction with various other wells and in situ recovery methods,
such as SAGD and
CSS, where the geothermal well is located above, beside, below or offset with
respect to another
well that recovers production fluid.
100142 ] In some implementations, the heating of the heavy hydrocarbon zone
24 is
performed by conduction of the geothermal heat through the heat-receiving well
section 16 and
the heat-transmission well section 18 and into the heavy hydrocarbon zone 24
in the absence of
fluid injection into the geothermal well 14 and/or heavy hydrocarbon zone 24.
Date Recue/Date Received 2022-09-29
33
100143 ] In some implementations, the heating of the heavy hydrocarbon zone
24 is
performed by conduction of the geothermal heat from the heat-receiving well
section 16 to the
heat-transmission well section 18, and by downhole injection of an injection
fluid 32 that is heated
in the heat-transmission well section 18 and then injected or released into
the heavy hydrocarbon
zone 24.
100144 ] In other implementations, the heating of the heavy hydrocarbon
zone 24 is
performed by conduction of the geothermal heat from the heat-receiving well
section 16 to the
heat-transmission well section 18, and by injection of a hot native fluid 36
that is received from
the geothermal zone 22 of the formation through heat-receiving well section
16, transported uphole
to the heat-transmission well section 18, and then injected into the heavy
hydrocarbon zone 24.
100145 ] In some implementations, the heating of the heavy hydrocarbon zone
24 includes a
circulation fluid downhole into the geothermal well 14, wherein the
circulation fluid is circulated
through the heat-receiving well section 16 to be heated to form a heated fluid
32, and then the
heated fluid is transported to the heat-transmission well section 18 for
injection into the heavy
hydrocarbon zone 24 or for indirect heating of the heavy hydrocarbon zone 24.
Further Implementations and Aspects
100146 ] Fig. 15 and 16 generally discloses systems in which the geothermal
well is
configured and operated to not only provide geothermal heat to a target
subterranean zone, such
as the hydrocarbon zone 24, but also to bring a portion of the heat and/or hot
native fluid 36to
surface. The geothermal heat brought to surface could then be used for various
purposes,
including steam generation for surface or subterranean applications,
electricity generation, and/or
other uses.
100147 ] Fig. 15 and 16 illustrates the system 10 that includes the
geothermal well 14 which
may transport geothermal heat by conduction from the hot geothermal zone 22
for recovery to the
surface 26. The geothermal well 14 would thus be appropriately completed with
equipment for
enabling heat conduction into the hydrocarbon zone 24 and up to the surface
26.
100148 ] According to this example implementation, the geothermal well 14
can include the
elongated component 30 or using a supercritical fluid 42, as previously
described, located in the
Date Recue/Date Received 2022-09-29
34
wellbore of the geothermal well and composed of a heat conductive material,
and the heat is
transmitted upward (or "uphole" as depicted by the arrows in Fig. 8) from the
heat-receiving well
section 16 to the surface 26 by conduction. The elongated component 30 is
constructed so as to
promote heating from the geothermal zone, conducting heat into the hydrocarbon
zone 24 and
also uphole to the surface 26. The elongated component 30 may therefore
further extend into the
upper well section 28 and up to the surface 26. Furthermore, the insulated
casing or other
insulation equipment may be present in the upper well section 28 of the
geothermal well 14 to
limit heat loss to the formation that is uphole of the hydrocarbon zone 24
before the heat reaches
the surface. In such systems, the insulation can be provided where heat loss
is to be minimized
and not in the regions where heat is to be received and delivered. Thus,
different segments of the
elongated component 30 could be insulated while others are exposed to promote
heat transfer
with the formation or surface equipment. In some aspects, the elongated
component 30 may be
replaced by a supercritical fluid 42 which is used to conduct geothermal heat
from the heat-
receiving well section 16 to the heat-transmission well section 18 and further
to upper-well
section 28 for recovery to the surface 22.
100149 ] In some implementations, the system 10 also involves allowing a
hot native fluid
36 to flow from the geothermal zone 22 through the geothermal well 14 to the
surface 26, as also
depicted in Fig. 15 and 16. The hot native fluid 36 may be the hot native
fluid as previously
described. In this scenario, the hot native fluid as well as heat conducted
from the geothermal
zone would be brought up to the hydrocarbon zone for heating. A portion of the
heat can then be
conducted up to the surface and/or at least a portion of the hot native fluid
can be brought up to
surface. The heat that is in the hot native fluid and/or obtained through
conduction, can then be
used at surface for various applications. In some implementations, the system
10 involves
allowing a hot native fluid 36 to flow from the geothermal zone 22 through the
geothermal well
14 to the surface 26, in the absence of conduction through a solid medium.
Therefore, according
to this implementation, the geothermal well 14 may not include the elongated
component 30.
100150 ] The geothermal heat and/or hot native fluid 36 recovered to the
surface 26 may be
utilized as thermal energy and/or utilized to produce electrical energy. For
example, geothermal
heat may be used directly for heating, such as for heating homes or for
heating nearby or distant
oil pipelines to maintain a low oil viscosity at the surface. Depending on the
quantity of
Date Recue/Date Received 2022-09-29
35
geothermal heat that is obtained at surface, it can be used to heat pipelines
and surface equipment
that is located proximate to the well head and/or at remote locations.
Geothermal heat may also
be used to generate electricity, such as for example by first heating water
using the recovered
geothermal heat to generate steam, and powering steam turbines. Steam can then
be used for
heating, as described above. Steam and electricity may be produced at the
surface, optionally
using steam insulated tanks to prevent cooling of the steam. In some cases,
steam is directly
obtained from the geothermal well 14 as the hot native fluid 36 from the
geothermal zone. The
vacuum insulated tubing may be extended in regions of the geothermal well 14,
such as in the
upper well section 28, to prevent cooling of the hot native fluid 36 (e.g.,
steam). Furthermore,
geothermal heat obtained by embodiments of the system described herein may be
used to power
a thermoelectric generator to generate electricity..
100151 ] In some scenarios, as described in Fig. 10, injection fluid 32 may
be injected into
the geothermal well and is heated by the hot geothermal zone. This
geothermally-heated injection
fluid may then be recovered to the surface for use as thermal energy,
electrical energy, and/or for
injection (or reinjection) into a nearby or distant heavy hydrocarbon zone
(Fig. 19).
100152 ] In some case, the recovered geothermal heat, hot native fluid 36,
and/or
geothermally-heated injection fluid 12 may be recirculated or reinjected into
a nearby or distant
heavy hydrocarbon zone 24 for heating and recovery of heavy hydrocarbons. In
some cases, the
recovered geothermal heat and/or hot native fluid is recirculated or
reinjected into the same
geothermal well 14. In some cases, the recovered geothermal heat and/or hot
native fluid is
recirculated or reinjected into one or more nearby or distant geothermal wells
as described herein,
or abandoned, previously used, or repurposed wells (e.g., injection or
production well). The
recovered recovered geothermal heat, hot native fluid 36, and/or geothermally-
heated injection
fluid, can therefore be re-injected into a geothermal well for recovering
heavy hydrocarbons from
the same subsurface formation and/or a second nearby or distant subsurface
formation.
100153 ] In some aspects, the systems described herein may not employ the
use of a boiler
and/or a heat exchanger at the surface to maintain the temperature of the
geothermal heat, hot
native fluid, or geothermally-heated injection fluid. The temperature of
recovered geothermal
Date Recue/Date Received 2022-09-29
36
heat, hot native fluid, or geothermally-heated injection fluid may be
maintained using known
thermal insulation techniques and tubing
100154 ] In some scenarios, a portion of the geothermal heat can be used in
a surface facility
to generate steam. It is also possible to use a portion of the geothermal heat
for steam generation
using a near-surface steam generator, as well as steam insulated tanks,
located underground but
close to the surface (i.e., near surface).
100155 ] In some cases, the geothermal well 14 could be operated in
different heat recovery
modes over time. For example, the geothermal well could initially be operated
in one heat
recovery mode where geothermal heat is only brought up to the hydrocarbon
zone, and then at a
later phase in operations the geothermal well could be switched to operate in
another heat
recovery mode in which geothermal heat is only brought to surface or is
delivered to the
hydrocarbon zone and the surface. In this manner, the operation of the
geothermal well could be
modified over time depending on heat requirements and end-uses. For example,
after the
hydrocarbon recovery process for a given reservoir has been completed, the
geothermal well
could be converted to a heat-to-surface well to continue delivering heat to
the surface.
100156 ] In some scenarios, the systems in which the geothermal well 14 is
configured and
operated to bring geothermal heat from a hot geothermal zone to the surface
may be configured
and operated in the absence of recovery of hydrocarbons, as depicted in Fig.
17 and 18. Therefore,
the geothermal well 14 may not include the heating of a target subterranean
zone (e.g.,
hydrocarbon zone) for the purpose of enhancing recovery of fluid from the
zone. According to
this implementation, geothermal heat may be recovered to the surface, or near-
surface, by
conduction (e.g., with the use of the elongated component 30 [Fig. 17] or a
supercritical fluid 42
[Fig. 18]). In some cases, a hot native fluid 36 (e.g., steam) from a
subterranean zone may be
recovered to the surface, or near-surface, in the presence or absence of
conduction (i.e., absence
of the elongated component 30). The system may include any one of the
geothermal wells
including one or more the sections described herein. For example, if
geothermal heat and/or hot
naïve fluid is not being delivered into a hydrocarbon zone, the heat-
transmission well section may
not be necessary and may be configured differently (e.g., it may be insulated
to discourage heat
Date Recue/Date Received 2022-09-29
37
transmission into that zone). Recovered fluid and/or heat may be used at
surface to generate
electricity and/or steam, as previously described.
100157 ] According to some implementations, the system that is configured
and operated to
bring geothermal heat from a hot geothermal zone to the surface in the absence
of recovery of
hydrocarbons, as described in Fig. 17 and 18, may include the use of offshore
wells or onshore
wells, and such wells may be abandoned or previously-used. Such wells may
include production
wells, such as oil production wells and/or injection wells, and may or may not
be further drilled
into to reach deeper and/or hotter geothermal zones. At least a downhole
portion of the abandoned
well may be located in the geothermal zone of the formation. Initial
temperature readings of
abandoned wells may be obtained to determine whether the well is suitable for
recovering
geothermal heat to the surface. Abandoned wells may be configured with the
elongated
component 30, supercritical fluid 42, and/or insulated tubing, as previously
described, extending
downhole for recovery of geothermal heat by conduction. Furthermore, a hot
native fluid 36 (e.g.,
steam) may be recovered, in the presence or absence of conduction, using
abandoned wells.
Recovered fluid and/or heat may be used to generate electricity and/or steam,
as previously
described.
100158 ] When abandoned or shut-in well are used, the wells can be
recompleted to provide
completion equipment suitable for retrieving the geothermal heat. For example,
a shut-in well
could be recompleted by running in an elongated component with predetermined
segments that
are insulated and exposed to promote conduction of heat from hot zones up to
the surface while
inhibiting heat loss to the formation. The elongated component in the upper
vertical section of the
wells could be insulated, for example, while the deeper parts of the elongated
component are
exposed to receive geothermal heat. Alternatively, shut-in wells could be
leveraged without
completion with an elongated component but are configured so that heat that
transfers up to the
surface is captured and utilized. This could involve surface equipment that is
connected to the
wellhead to capture heat that is transferred via conduction and/or convection
to surface.
Methods for recovering geothermal heat
100159 ] According to another general aspect of the technology, there is
described a method
for recovering geothermal heat from a subsurface formation to the surface.
Date Recue/Date Received 2022-09-29
38
100160 ] According to this aspect, the method includes recovering
geothermal heat obtained
by a geothermal well and transporting the geothermal heat by conduction and/or
transporting a hot
native fluid 36 from the geothermal zone 22, to the surface 26. In some cases,
the method utilizes
the systems 10 or geothermal wells 14 according to example implementations
described herein,
either alone or in combination. The method may include heating a heavy
hydrocarbon zone 24 of
the formation and mobilizing heavy hydrocarbons 12 contained therein with a
portion of
geothermal heat, and optionally a portion of the hot native fluid 36, obtained
from the geothermal
zone 22 of the formation, for recovery of the mobilized heavy hydrocarbons 12
to the surface 26
by a nearby production well 20, as previously described.
100161 ] According to another general aspect, there is described a method
for recovering
geothermal heat from a subsurface formation using an abandoned well (e.g.,
production or
injection well). At least a downhole portion of the abandoned well may be
located in the
geothermal zone of the formation. Initial temperature readings of abandoned
wells may therefore
be obtained to determine whether the well is suitable for recovering
geothermal heat to the
surface, or near-surface. The method may therefore include an initial step of
determining suitable
wells to be used as geothermal wells, and the determining step can include
temperature sensing.
The temperature sensing can use equipment that exists in the well, or
instrumentation that is
deployed into the abandoned well to obtain temperature and/or pressure
readings. The method
may also include drilling downhole into the abandoned well to reach a
geothermal zone of the
formation to extend the well and reach more elevated temperatures. The
abandoned well may be
configured to receive the elongated component 30 or a supercritical fluid 42,
as previously
described, to reach the geothermal zone and transmit geothermal heat uphole in
the well by
conduction. Insulated casing may be applied at any point in the well to
prevent heat loss.
Furthermore, the abandoned well may be configured to receive a hot native
fluid 36 from the
geothermal zone of the formation, and transport the hot native fluid uphole in
the well to the
surface.
100162 ] It will be appreciated that, for simplicity and clarity of
illustration, where
considered appropriate, reference numerals may be repeated among the Figures
to indicate
corresponding or analogous elements or steps. In addition, numerous specific
details are set forth
in order to provide a thorough understanding of the exemplary implementations
described herein.
Date Recue/Date Received 2022-09-29
39
However, it will be understood by those of ordinary skill in the art, that the
implementations
described herein may be practiced without these specific details. In other
instances, well-known
methods, procedures and components have not been described in detail so as not
to obscure the
implementations described herein. Furthermore, this description is not to be
considered as limiting
the scope of the implementations described herein in any way but rather as
merely describing the
implementation of the various implementations described herein.
100163 ] The use of the word "a" or "an" when used in conjunction with the
term
"comprising" in the claims and/or the specification may mean "one" but it is
also consistent with
the meaning of "one or more", "at least one", and "one or more than one".
100164 ] As used in this specification and claim(s), the words "comprising"
(and any form
of comprising, such as "comprise" and "comprises"), "having" (and any form of
having, such as
"have" and "has"), "including" (and any form of including, such as "includes"
and "include") or
"containing" (and any form of containing, such as "contains" and "contain")
are inclusive or open-
ended and do not exclude additional, unrecited elements or method steps.
100165 ] Other objects, advantages and features of the present description
will become more
apparent upon reading of the following non-restrictive description of specific
implementations
thereof, given by way of example only with reference to the accompanying
drawings.
Date Recue/Date Received 2022-09-29
