Note: Descriptions are shown in the official language in which they were submitted.
APPARATUSES, SYSTEMS, AND METHODS FOR FLUID INFLOW CONTROL
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of US Provisional Patent Application
Serial
No. 63/139,077, filed January 19, 2021.
TECHNICAL FIELD
The present disclosure generally relates to apparatuses, systems, and methods
for
controlling fluid to flow into a base pipe downhole in a well and in
particular to apparatuses,
systems, and methods for controlling water to flow into a base pipe downhole
in a well while
allowing hydrocarbon to flow thereinto.
BACKGROUND
Steam-assisted gravity drainage (SAGD) is a widely used, enhanced oil recovery
technology for producing heavy crude oil and bitumen reserves. In a SAGD
process, a pair of
horizontal wells is drilled with one horizontal well (denoted the "injection
well" or the "injector"
hereinafter) positioned a few meters above the other well (denoted the
"production well" or the
"producer" hereinafter). Steam is continuously injected into a reservoir
through the upper injection
well. The steam heats the bitumen and reduces its viscosity, allowing the
hydrocarbon to drain to
the lower production well and be pumped to the surface.
The energy consumption of SAGD is highly dependent on steam requirements. The
steam
front can be heavily influenced by factors such as reservoir heterogeneity,
fluid dynamics, and the
distance the production zone is away from the downhole pump. Uniform steam-
chamber growth
(confoimance) in a SAGD process promotes enhanced bitumen recovery, project
economics, and
environmental benefits. In contrast, uneven steam-chamber growth can lead to a
high steam-oil-
ratio and early breakthrough of steam and/or water in the producer, thereby
negatively affecting
the well economics and increasing the environmental footprint of the SAGD
operation.
An inflow control device is a device used in well completions that may utilize
fluid
properties to dynamically adjust the wellbore pressure distribution and
restrict the flow of
undesired fluids (for example, steam and water) into the base pipe of the
producer. This restriction
forces the steam to penetrate back into the reservoir for better heating
efficiency and evens out
production along the length of the producer. The design and mechanisms of
inflow control devices
may also be applied to producers in other types of thermal oil recovery
processes, for example,
cyclic steam stimulation (CS S) and steam flooding.
1
Date Recue/Date Received 2023-09-13
Therefore, there always exists a need for improved inflow control devices,
systems, and
methods to increase the efficiency and reduce the environmental impact of
steam-based heavy
crude and bitumen recovery processes.
SUMMARY
The present disclosure provides apparatus, systems, and methods for
controlling fluid flow
into a base pipe of a production well. An advantage of the present disclosure
is the provision of
apparatus, systems, and methods having improved characteristics over existing
technologies.
According to one aspect of the present disclosure, there is provided an
apparatus for
restricting water and/or steam in a fluid entering a base pipe in a wellbore,
the apparatus
comprising: a body having an exterior end and an interior end; at least one
inlet positioned on or
about the exterior end of the body for receiving the fluid; and a bore in
fluid communication with
the at least one inlet and extending within the body to the interior end
thereof, the bore comprising:
a first section in fluid communication with the at least one inlet for
decreasing a pressure of the
fluid by increasing a velocity thereof; a second section coupled to the first
section for allowing the
undersaturated or saturated water in the fluid to generate steam or allowing
the expansion of the
injected steam/vapor for partially or fully restricting, inhibiting or
blocking the bore; a third
section coupled to the second section for causing remaining undersaturated or
saturated water and
the injected or generated steam to conduct work to surrounding environment of
the bore to further
decrease the pressure of the fluid or to further expand the volume thereof for
generating more
volume of steam for partially or fully restricting, inhibiting or blocking the
bore; and an outlet for
discharging remainder of the fluid into the base pipe as the hydrocarbon-
enriched fluid.
According to one aspect of the present disclosure, there is provided an
apparatus for
coupling to a port on a sidewall of a base pipe in a wellbore, the apparatus
comprising: a body
having an exterior end and an interior end; at least one inlet positioned on
or about the exterior
end of the body for receiving a fluid, the fluid comprising water in at least
one of a liquid phase
and a gas phase; an outlet on or about the interior end of the body; and a
bore extending within
the body and in fluid communication with the at least one inlet and the
outlet; the bore comprises:
a first section in fluid communication with the at least one inlet for
decreasing a pressure of the
fluid by increasing a velocity thereof; a second section coupled to the first
section for causing a
volume of steam to at least restrict a flow of the fluid in the bore; and a
third section coupled to
the second section and in fluid communication with the outlet for causing more
volume of steam
to at least further restrict the flow of the fluid in the bore.
In some embodiments, the first section comprises a first end in fluid
communication with
the at least one inlet, a second end, and a first length defined therebetween,
the first section having
2
Date Recue/Date Received 2023-09-13
a first inner diameter (ID) continuously reducing from the first end to the
second end with a
maximum first ID at the first end.
In some embodiments, the second section extends from the second end to a third
end with
a second length defined therebetween, the second section having a uniform
second ID equal to the
first ID of the first section at the second end.
In some embodiments, the third section is coupled to the second section and is
in fluid
communication with the outlet for further decreasing the pressure or expanding
the volume of the
fluid for causing the more volume of steam to at least further restrict the
flow of the fluid in the
bore.
In some embodiments, the third section extends from the third end to a fourth
end in fluid
communication with the outlet, the third section having a third length defined
between the third
end and the fourth end, and the third section having a third ID continuously
increasing from the
third end to the fourth end with a maximum third ID at the fourth end.
In some embodiments, the third length is greater than the first length.
In some embodiments, the maximum third ID is greater than the second ID.
In some embodiments, the apparatus is configured for providing a steam volume
fraction
of at least 0.2 at the outlet with a mass flow rate within a predefined range.
According to one aspect of the present disclosure, there is provided an
apparatus
comprising: a body having an exterior end and an interior end; at least one
inlet positioned about
the exterior end of the body; an outlet on or about the interior end of the
body; and a bore extending
within the body and in fluid communication with the at least one inlet and the
outlet; the bore
comprises: a first section having a first end in fluid communication with the
at least one inlet, a
second end, and a first length defined therebetween, the first section having
a first inner diameter
(ID) continuously reducing from the first end to the second end with a maximum
first ID at the
first end; a second section extending from the second end to a third end with
a second length
defined therebetween, the second section having a uniform second ID equal to
the first ID of the
first section at the second end; and a third section extending from the third
end to a fourth end in
fluid communication with the outlet, the third section having a third length
defined between the
third end and the fourth end, and the third section having a third ID
continuously increasing from
the third end to the fourth end with a maximum third ID at the fourth end.
In some embodiments, the third length is greater than the first length.
In some embodiments, the maximum third ID is greater than the second ID.
In some embodiments, the first ID of the first section is linearly reduced
from the first end
to the second end.
3
Date Recue/Date Received 2023-09-13
In some embodiments, the third ID of the third section is linearly increased
from the third
end to the fourth end.
In some embodiments, the maximum first ID and the second ID are in a ratio
between 3.0:1
and 1.2:1.
In some embodiments, the maximum third ID and the second ID are in a ratio of
between 2.5:1 and 1.2:1.
In some embodiments, the third length and the first length are in a ratio of
at least 2:1.
In some embodiments, the at least one inlet is on a sidewall of the body
adjacent the
exterior end thereof.
In some embodiments, the at least one inlet is on an end-wall of the body at
the exterior
end thereof.
In some embodiments, the at least one inlets comprises two or more inlets.
In some embodiments, the apparatus is configured for providing a steam volume
fraction
of at least 0.2 at the fourth end with a mass flow rate within a predefined
range.
According to one aspect of the present disclosure, there is provided a
downhole system
comprising: a base pipe having one or more ports on a sidewall thereof, each
of the one or more
ports receiving therein an apparatus as described above for directing the
fluid into the base pipe;
and at least one filter for filtering solids in the fluid and directing the
fluid to the apparatus.
In some embodiments, the at least one filter is a sand screen.
In some embodiments, the system further comprises at least two isolation
components.
In some embodiments, the at least two isolation components comprise at least
two packers.
According to one aspect of the present disclosure, there is provided a method
for restricting
water in a fluid entering a base pipe in a wellbore, the method comprising:
(i) directing the fluid
from a hydrocarbon reservoir into a channel towards the base pipe; (ii)
decreasing a pressure of
the fluid in the channel by increasing a velocity thereof; (iii) causing a
volume of steam to at least
restrict a flow of the fluid in the channel; and (iv) causing more volume of
steam to at least further
restrict the flow of the fluid in the channel.
In some embodiments, said causing the more volume of steam to at least further
restrict
the flow of the fluid in the channel comprises: further decreasing the
pressure or expanding the
volume of the fluid for causing the more volume of steam to at least further
restrict the flow of the
fluid in the channel.
In some embodiments, said decreasing the pressure of the fluid in the channel
by increasing
the velocity thereof comprises: directing the fluid through a first section of
the channel, the first
section comprising a first end, a second end, and a first length defined
therebetween, the first
4
Date Recue/Date Received 2023-09-13
section having a first inner diameter (ID) continuously reducing from the
first end to the second
end with a maximum first ID at the first end.
In some embodiments, said causing steam to at least restrict the flow of the
fluid in the
channel comprises: directing the fluid through a second section of the
channel, the second section
.. extending from the second end to a third end with a second length defined
therebetween, the
second section having a uniform second ID equal to the first ID of the first
section at the second
end.
In some embodiments, said causing the more volume of steam to at least further
restrict
the flow of the fluid in the channel comprises: directing the fluid through a
third section of the
channel, the third section extending from the third end to a fourth end in
fluid communication with
the outlet, the third section having a third length defined between the third
end and the fourth end,
and the third section having a third ID continuously increasing from the third
end to the fourth
end with a maximum third ID at the fourth end.
In some embodiments, the method further comprises: providing a steam volume
fraction
of at least 0.2 at an exit point of the channel with a mass flow rate within a
predefined range.
In some embodiments, the method further comprises: directing the fluid through
at least
one solids filter prior to directing the fluid into the channel.
In some embodiments, the method further comprises: isolating a section of the
well about
the base pipe.
Other aspects and embodiments of the disclosure are evident in view of the
detailed
description provided herein.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the present disclosure will become more apparent
in the
following detailed description in which reference is made to the appended
drawings. The
appended drawings illustrate one or more embodiments of the present disclosure
by way of
example only and are not to be construed as limiting the scope of the present
disclosure.
FIG. 1 is a schematic diagram of a steam-assisted gravity drainage (SAGD) well
pair
comprising an injection well (the injector) and a production well (the
producer), according to an
embodiment of this disclosure, wherein the producer is equipped with an inflow-
control apparatus;
FIG. 2 is a schematic diagram of an exemplary producer in a cyclic steam
stimulation (CS S)
or steam flooding process, according to an embodiment of this disclosure,
wherein the producer
is equipped with an inflow-control apparatus;
FIG. 3A is a perspective view of the inflow-control apparatus shown in FIG. 1
or FIG. 2,
according to an embodiment of the present disclosure;
5
Date Recue/Date Received 2023-09-13
FIG. 3B is a cross-sectional view of the inflow-control apparatus shown in
FIG. 3A along
the cross-section line B-B;
FIG. 3C is a cross-sectional view of the inflow-control apparatus shown in
FIG. 3A along
the cross-section line C-C;
FIG. 4 is a cross-sectional view of the inflow-control apparatus shown in FIG.
3A along
the cross-section line C-C, showing the parameters thereof;
FIG. 5A is a side view of a base pipe, wherein the base pipe comprises a first
portion
having a plurality of ports on the sidewall thereof and a second portion
having a plurality of ribs
radially outwardly extending from the sidewall and circumferentially uniformly
distributed
thereon;
FIG. 5B is a side view of the base pipe shown in FIG. 5A with a plurality of
inflow-control
apparatuses shown in FIG. 3A received in respective ports and wires wrapping
on the ribs and
secured to the base pipe via an end-piece;
FIG. 5C is a side view of the base pipe shown in FIG. 5B, wherein the first
portion of the
base pipe is received in a housing;
FIG. 5D is a cross-sectional view of the base pipe shown in FIG. 5C along the
cross-section
line D-D;
FIG. 6 is a schematic diagram showing a portion of a downhole oil production
system,
according to an embodiment of the present disclosure;
FIG. 7 is a flowchart showing an exemplary process for controlling the flow of
a fluid into
a base pipe of a production well, according to an embodiment of the present
disclosure;
FIG. 8 is a flowchart showing an exemplary process for controlling the flow of
a fluid into
a base pipe of a production well, according to another embodiment of the
present disclosure;
FIG. 9 shows a plot of steam volume fraction to mass flow rate, used to
analyze the
performance of the inflow-control apparatus shown in FIG. 3A;
FIG. 10 shows critical cross-sections for the flow mechanisms when saturated
or near
saturated water and/or steam passes through an inflow-control apparatus shown
in FIG. 3A,
according to the present disclosure;
FIG. 11 shows a Pressure-Temperature Phase Equilibrium Diagram of solid-liquid-
gas
phase between ice, water, and steam;
FIG. 12 shows a Pressure-Enthalpy Phase Equilibrium diagram between water and
steam;
FIG. 13 shows a plot of pressure drop to mass flow rate for water with a steam
flash
mechanism, heat oil at typical downhole conditions, and a hypothetical water
that does not have
flashing capabilities, which is used to analyze the performance of the inflow-
control apparatus
shown in FIG. 3A;
6
Date Recue/Date Received 2023-09-13
FIGs. 14A and 14B show model images of the mainstream flashed vapor from the
water
phase in an inflow-control apparatus shown in FIG. 3A, according to the
present disclosure
(FIG. 14A) and an inflow-control apparatus not having the features of the
inflow-control apparatus
of the present disclosure (FIG. 14B);
FIG. 15A shows the testing results of the pressure differences between the
inlet and outlet
of the inflow-control apparatus shown in FIG. 3A under different testing
conditions;
FIG. 15B shows the testing results of the steam volume fractions at the inlet
and outlet of
the inflow-control apparatus shown in FIG. 3A under different testing
conditions;
FIG. 16 is a cross-sectional view of the inflow-control apparatus shown in
FIG. 1 or FIG. 2,
according to an embodiment of the present disclosure;
FIG. 17 is a cross-sectional view of the inflow-control apparatus shown in
FIG. 1 or FIG. 2,
according to another embodiment of the present disclosure;
FIG. 18 is a cross-sectional view of a base pipe shown with a plurality of
inflow-control
apparatuses shown in FIG. 16 received in respective ports, according to an
embodiment of the
present disclosure;
FIG. 19A is a cross-sectional view of a base pipe having a plurality of inflow-
control
apparatuses folined on a sidewall thereof, according to an embodiment of the
present disclosure;
and
FIG. 19B is a schematic diagram showing a portion of a downhole oil production
system,
according to an embodiment of the present disclosure.
DETAILED DESCRIPTION
Unless otherwise defined, all technical and scientific terms used herein
generally have the
same meaning as commonly understood by one of ordinary skill in the art to
which this disclosure
pertains. Exemplary terms are defined below for ease in understanding the
subject matter of the
present disclosure.
Herein, the term "about", when referring to a measurable value (for example, a
dimension),
is meant to encompass variations of 10%, 5%, 1%, +0.5% or 0.1% of the
specified amount.
When the value is a whole number, the term about is meant to encompass decimal
values, as well
the degree of variation just described.
The teitn "comprise" as is used in this description and in the claims, and its
conjugations,
is used in its non-limiting sense to mean that items following the word are
included, but items not
specifically mentioned are not excluded.
The present disclosure provides improved apparatus, systems, and methods for
controlling
flow of fluids into a base pipe of a production well. As used herein, the term
"production well" is
7
Date Recue/Date Received 2023-09-13
intended to refer to a well from which a hydrocarbon is recovered and, as
appreciated by the skilled
person in the art, may be interchangeably used with the term "producer". In
some embodiments,
a production well may be a horizontal well in steam-assisted gravity drainage
(SAGD) operations.
In some other embodiments, a production well may be a horizontal well in
cyclic steam
stimulation (CSS) or steam flooding operations. The skilled person in the art
will appreciate that
while embodiments of the present disclosure are described in the context of
horizontal wells, use
in vertical wells is applicable. For example, in some embodiments, a
production well may be a
vertical well in a CSS or a steam-flooding operation.
Embodiments of the present disclosure will now be described with reference to
FIG. 1
through FIG. 18, which show non-limiting embodiments of the present
disclosure.
FIG. 1 and FIG. 2 show exemplary enhanced hydrocarbon-recovery processes for
which
the apparatus, systems, and methods of the present disclosure may be used. For
ease of description,
the terms "hydrocarbon", "bitumen", and "oil" may be used interchangeably
hereinafter.
FIG. 1 shows an exemplary SAGD process for recovering bitumen from a reservoir
20,
according to an embodiment of this disclosure. In this embodiment, steam is
injected from the
surface into the reservoir 20 through an injection well 10 (steam flow
indicated by arrows 18 in
injection well 10). As the steam heats bitumen in the reservoir 20, the
viscosity of the bitumen is
reduced and the bitumen drains towards a production well 12. The bitumen is
brought to surface
through a base pipe 14 of the production well 12 using a pump 16. As used
herein, the term "base
.. pipe" is intended to refer to a tubular, a tubing, a liner, or the like in
a cased or uncased production
well, or a perforated casing in a production well. Fluids from a reservoir are
generally brought to
the surface through the base pipe. In this embodiment, one or more inflow-
control apparatuses 100
may be coupled to the base pipe 14 for controlling fluid flow into the base
pipe 14.
FIG. 2 shows an exemplary CSS producer for recovering bitumen from reservoir
20
through the base pipe 14, according to an embodiment of this disclosure. In
this embodiment, the
base pipe 14 comprises one or more inflow-control apparatuses 100 for
controlling fluid flow into
the base pipe 14.
FIG. 3A is a perspective view of the inflow-control apparatus 100 according to
an
embodiment of this disclosure. FIG. 3B is a cross-sectional view of the
apparatus 100 shown in
.. FIG. 3A along the cross-section line B-B. FIG. 3C is a cross-sectional view
of the apparatus 100
shown in FIG. 3A along the cross-section line C-C.
As those skilled in the art will appreciate, the inflow-control apparatus 100
may improve
the steam-to-oil ratio in SAGD and/or CSS processes.
As shown in FIGs. 3A to 3C, the inflow-control apparatus 100 comprises a body
110
having an exterior end 110A, an interior end 110B, and a central axis A-A
defined therebetween.
8
Date Recue/Date Received 2023-09-13
As used herein, the term "exterior end" is intended to refer to the terminus
of the body 110 that is
facing the exterior side of the base pipe 14 when the apparatus 100 is
operationally coupled to the
base pipe 14. As used herein, the term "interior end" is intended to refer to
the terminus of the
body 110 facing the interior side of the base pipe 14 when the apparatus 100
is operationally
coupled to the base pipe 14. By "operationally coupled to" it is meant that
the apparatus 100 is
coupled to the base pipe 14 in a position to control fluid flow into the base
pipe 14.
The body 110 may be of any suitable shape and size and made of any suitable
material.
For example, in various embodiments, the exterior end 110A may comprise a
hexagonal profile,
a circular profile, or an octagonal profile from a plan view. In an
embodiment, the body 110
comprises a metal or a metal alloy. In another embodiment, the body 110
comprises steel such as
conventional steel or high tensile steel.
In the embodiment shown in FIGs. 3A to 3C, the body 110 comprises a head
portion 114
on the exterior side thereof and a coupling portion 112 on the interior side
thereof. The coupling
portion 112 comprises threads 116 on the outer surface thereof for coupling to
a threaded port on
the sidewall of the base pipe 14 (that is, a so-called "threaded connection";
see FIGs. 5A and 5B).
Of course, those skilled in the art will appreciate that in other embodiments,
other suitable
coupling structure such as for example a pin, a compression fitting, a flange,
welding, or the like
may be used for coupling the inflow-control apparatus 100 (or more
specifically the coupling
portion 112) to the port of the base pipe 14.
In this embodiment, the head portion 114 of the body 110 comprises at least
one inlet 120
for introducing a fluid into the base pipe 14 (described in more detail
later). Each of the at least
one inlet 120 radially inwardly extends from the outer surface of the sidewall
of the head
portion 114 to a central bore 130 extending from a position in the head
portion 114 in proximity
with the exterior end 110A to the interior end 110B of the body 110. The at
least one inlet 120
and the central bore 130 thus foun a channel for directing fluid from the
exterior (outside of the
exterior end 110A) towards the interior end 110B. In various embodiments, the
at least one
inlet 120 may comprise any suitable shape and size, and may be perpendicular
to the central axis
A-A of the body 110 or at an angle thereto. In embodiments where the head
portion 114 comprises
a plurality of inlets 120, it may be preferable that the inlets 120 are
circumferentially uniformly
distributed around the perimeter of the head portion 114.
In this embodiment, the central bore 130 is coaxial with the axis A-A. As will
be
appreciated, by "coaxial with the axis" it is meant that the central bore 130
is symmetric about the
axis A-A. As shown in FIG. 4, the central bore 130 in this embodiment
comprises, naming from
the exterior side to the interior side thereof, a convergent section 132, a
throat section 134, and a
divergent section 136.
9
Date Recue/Date Received 2023-09-13
The convergent section 132 of the central bore 130 extends from the exterior
end 110A
(also denoted as the first convergent end 132A of the convergent section 132)
to a second
convergent end 132B with a continuously reduced inner diameter (ID) De and a
length Lc defined
therebetween. For example, as shown in FIG. 4, the convergent section 132 of
the central bore 130
may have a conical frustum shape with the ID thereof linearly reducing from
the first convergent
end 132A to the second convergent end 132B thereof.
The throat section 134 extends from the second convergent end 132B of the
convergent
section 132 (also denoted as the first throat end 134A of the throat section
134) to a second throat
end 134B with a uniform ID DT and a length LT defined therebetween. Herein,
the teim "unifoiiii
ID of the throat section" refers to the ID D' of the throat section which
remains substantially or
completely unchanged over the entire length thereof. For example, as shown in
FIG. 4, the throat
section 134 of the central bore 130 may have a cylindrical shape with the ID
DT substantially equal
to the ID De of the convergent section 132 at the second convergent end 132B.
In this example,
the length LT of the throat section 134 is less than the length Le of the
convergent section 132.
The divergent section 136 extends from the second throat end 134B of the
throat
section 134 (also denoted as the first divergent end 136A of the divergent
section 136) to the
interior end 110B (also denoted as the second divergent end 136B of the
divergent section 136,
which is also the outlet of the bore 130) with a continuously increasing ID Du
and a length LD
defined therebetween. For example, as shown in FIG. 4, the divergent section
136 of the central
bore 130 may have a conical frustum shape. More specifically, the ID DD of the
divergent
section 136 as shown in FIG. 4 has its minimum at the first divergent end 136A
substantially equal
to the ID DT of the throat section 134, and linearly increases to its maximum
at the second
divergent end 136B. In this embodiment, the length LD of the divergent section
136 is greater than
the length Lc of the convergent section 132.
The inflow-control apparatus 100 disclosed herein may be used in various
applications
such as SAGD and/or CSS for cavitating, flashing, or expanding undersaturated
or saturated water
to steam or vapor and preventing the water from going into the base pipe 14.
Herein, the term
"water", unless otherwise explicitly specified, refers to water in the liquid
phase, and terms "steam"
and "vapor" (which may be used interchangeably) refer to water in the gas
phase.
In an embodiment, the inflow-control apparatus 100 may provide a steam volume
fraction
(SVF) of at least 0.2 at the second divergent end 136B with a mass flow rate
within a predefined
range. As will be appreciated, the term "steam volume fraction" of a mixture
of water and
steam/vapor is the volume of the constituent steam measured as the volume
thereof prior to mixing,
divided by the total volume of the constituent steam and water of the mixture
measured as the
volumes thereof prior to mixing, the term "saturated water" refers to water
that is at temperature
Date Recue/Date Received 2023-09-13
and pressure conditions where the liquid is about to vaporize, and the term
"undersaturated water"
refers to water that is a few degrees (for example, about 3 C to 20 C) lower
than its saturation
temperature at the corresponding pressure. In an embodiment, the inflow-
control apparatus 100
may provide a steam volume fraction of at least 0.2 (for example, about 0.2 to
0.95 in some
.. embodiments) at the second divergent end 136B with the mass flow rate at
the second divergent
end 136B within a predefined range. Such a mass flow rate for achieving a
steam volume fraction
of at least 0.2 at the second divergent end 136B may vary depending on the
dimensions of the
inflow-control apparatus 100. In a particular embodiment, the inflow-control
apparatus 100 may
provide a steam volume fraction of at least 0.2 at the second divergent end
136B with a mass flow
rate of about 0.08 kilogram per second (kg/s) to about 0.2 kg/s.
The parameters of the inflow-control apparatus 100 may be carefully selected
for
achieving an improved inflow control performance. For example, in an
embodiment, the
maximum ID Dc of the convergent section 132 and the ID DT of the throat
section 134 are in a
ratio of less than or equal to about 3:1. In an embodiment, the maximum ID Dc
of the convergent
section 132 and the ID DT of the throat section 134 are in a ratio of between
3.0:1 and 1.2:1. For
example, in some embodiments, the maximum ID Dc of the convergent section 132
and the ID
DT of the throat section 134 may be in a ratio of about 2.9:1, 2.8:1, 2.7:1,
2.6:1, 2.5:1, 2.4:1, 2.3:1,
2.2:1, 2.1:1, 2:1, 1.9:1, 1.8:1, 1.7:1, 1.6:1, 1.5:1, 1.4:1, 1.3:1, or 1.2:1.
In a particular embodiment,
the maximum ID Dc of the convergent section 132 and the ID DT of the throat
section 134 may
be in a ratio of 2: L
In an embodiment, the maximum ID DD of the divergent section 136 and the ID DT
of the
throat section 134 are in a ratio less than or equal to about 2.5:1. In an
embodiment, the maximum
ID DD of the divergent section 136 and the ID DT of the throat section 134 are
in a ratio of
between 2.5:1 and 1.2:1. For example, in some embodiments, the maximum ID DD
of the
.. divergent section 136 and the ID DT of the throat section 134 are in a
ratio of 2.4:1, 2.3:1, 2.2:1,
2.1:1, 2:1, 1.9:1, 1.8:1, 1.7:1,.6:1, 1.5:1, 1.4:1, 1.3:1, or 1.2:1. In a
particular embodiment, the
maximum ID DD of the divergent section 136 and the ID DT of the throat section
134 are in a ratio
of 2:1.
In an embodiment, the length LD of the divergent section 136 and the length Lc
of the
.. convergent section 132 are in a ratio greater than or equal to 2:1. For
example, in some
embodiments, the length LD of the divergent section 136 and the length Lc of
the convergent
section 132 are in aratio of2:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1,
2.7:1, 2.8:1, 2.9:1, 3:1,3.2:1,
3.3:1,3.4:1,3.5:1,3.6:1,3.7:1, 3.8:1, 3.9:1, 4:1, 4.1:1, 4.2:1, 4.3:1, 4.4:1,
4.5:1, 4.6:1, 4.7:1, 4.8:1,
4.9:1, or 5:1. In a particular embodiment, the length LD of the divergent
section 136 and the length
Lc of the convergent section 132 are in a ratio of 3.5:1.
11
Date Recue/Date Received 2023-09-13
The inflow-control apparatus 100 of the present disclosure may provide an
environment
for flashed vapor from water phase and/or injected steam to conform to the
wall of the divergent
zone 136. Further, the apparatus 100 of the present disclosure may increase
the amount of flashed
steam and/or the volume of the injected steam as compared to existing inflow
control device
.. technologies.
FIG. 3B is the schematic cross-sectional view of the inflow-control apparatus
100,
showing the six inlet channels 120, the second convergent end 132B, the throat
section 134, and
the second divergent end 136B. In this embodiment, the six inlet channels 120
are equally spaced
apart around the perimeter of the exterior end 110A, and each of the six inlet
channels 120 is
perpendicular to the axis A-A of the body 110. As those skilled in the art
will appreciate, such a
perpendicular arrangement between the inlet channels 120 and the axis of the
body 110 may
prevent the fluid inflow from forming a vortex or tortuous flow in the inflow-
control apparatus 100.
FIGs. 5A to 5D show the assembling of an inflow-control assembly 200 having a
plurality
of the inflow-control apparatus 100.
FIG. 5A shows a base pipe 14 comprising a first portion having a plurality of
ports 210 on
the sidewall 212 thereof and a second portion having a plurality of ribs 214
radially outwardly
extending from the sidewall 212 and circumferentially uniformly distributed
thereon.
FIG. 5B shows the base pipe 14 with a plurality of inflow-control apparatuses
100 received
in respective ports 210 and wires 216 wrapping on the ribs 214 and secured to
the base pipe 14
via an end-piece 218 thereby forming a solids filter or screen 220.
FIG. 5C illustrates the base pipe 14 shown in FIG. 5B with the first portion
received in a
housing 232. FIG. 5D is a cross-sectional view of the base pipe 14 shown in
FIG. 5C along the
cross-section line D-D.
As shown, the housing 232 comprises an end-wall 234 on a first end and engages
the solids
.. filter 220 on a second end longitudinally opposite to the first end. The
housing 232 and the first
portion of the base pipe 14 form an annulus 242 in fluid communication with
the annulus 244
between the solids filter 220 and the base pipe 14. The end-wall 234 of the
housing 232 and the
end-piece 218 of the solids filter 220 sealingly enclose the annuluses 242 and
244.
FIG. 6 is a schematic diagram showing a portion of a downhole oil production
system 300
such as a SAGD system, according to some embodiments of the present
disclosure. As shown, the
system 300 comprises the base pipe 14 extended in a wellbore 302 within a
reservoir 20 and
having the inflow-control assembly 200 shown in FIGs. 5C and 5D installed
thereon. In these
embodiments, the wellbore 302 may be an injection well or a production well,
and may be cased
or uncased.
12
Date Recue/Date Received 2023-09-13
A pair of packers 304 are coupled to the base pipe 14 and engages the wellbore
302 for
sealingly enclosing a portion of the annulus 306 between the base pipe 14 and
the wellbore 302.
In the embodiments wherein the wellbore 302 is a cased wellbore, the portion
enclosed between
the packers 304 is perforated for allowing a fluid 308 (which generally
comprises water and
hydrocarbon with solids (for example, sand) suspending therein) to flow from
the reservoir 20
into the enclosed annulus 306.
The base pipe 14 between the packers 304 comprises the ports 210 each
receiving therein
an inflow-control apparatus 100 (see FIGs. 5C and 5D), thereby forming a
plurality of inflow-
control ports.
In operation, the fluid 308 flows from the reservoir 20 through the solids
filter 220 into the
annulus 244 with at least a substantive portion of the solids contained
therein being filtered out.
The filtered fluid then flows through the annuluses 244 and 242 into the
inflow-control
apparatuses 100 wherein a substantive portion of water is rejected while the
hydrocarbon thereof
(as well as a reduced amount of water) continues to flow into the base pipe
14.
FIG. 7 shows a process 500 for controlling the flow of a fluid into a base
pipe 14 of a
production well, according to an embodiment of this disclosure. In this
embodiment, the base
pipe 14 comprises a plurality of inflow-control ports on the sidewall thereof
(for example, a
plurality of ports 210 coupling with a plurality of inflow-control apparatuses
100 as described
above). The process 500 comprises:
Step 502: directing the fluid from a hydrocarbon reservoir into the plurality
of inflow-
control ports and flowing along respective channels towards the interior of
the base pipe 14 by,
for example, directing the fluid through the at least one inlet 120 of the
inflow-control
apparatus 100 in each ports 120 and flowing along the bore 130 towards the
interior of the base
pipe 14. In an embodiment, step 502 comprises draining the fluid by gravity
after heating a
hydrocarbon-containing reservoir with steam.
Step 504: decreasing the pressure (that is, causing pressure drop) of the
fluid by increasing
the velocity thereof. The increasing of the velocity of the fluid may be
achieved by, for example,
directing the fluid through the converging section 132 of the central bore 130
of the inflow-control
apparatus 100 in each port 120.
Step 506: allowing undersaturated or saturated water contained in the fluid
(if any) to
sufficiently "flash" or vaporize to steam and/or allowing injected steam/vapor
to expand its
volume by, for example, directing the pressure-decreased fluid through the
throat section 134 of
the central bore 130 of the inflow-control apparatus 100 in each port 120. As
will be appreciated,
the term "flashing" refers to vaporization that occurs when an undersaturated
or saturated liquid,
such as for example saturated or near saturated water (for example, typically
within 0 C to 10 C
13
Date Recue/Date Received 2023-09-13
lower than the saturation temperature at the corresponding pressure),
undergoes a reduction in
pressure. As will be appreciated, the term "expanding" refers to the volume
expansion that occurs
when an injected steam or vapor undergoes a change in pressure and
temperature.
Step 508: causing the mixed water and steam (if any) to conduct work to the
surrounding
environment by expanding the fluid volume, for example, directing the mixed
liquid and steam
through the divergent section 136. In some embodiments, the steam volume at
the second
divergent end 136B may be 1% to 20% larger in comparison to that at the second
throat end 134B.
If associated with further pressure decrease in this step, it may cause water
in the fluid (if any) to
further vaporize to steam.
Subsequently, the steam generated in steps 506 and 508 (if any), while being
discharged
into the interior of the base pipe 14, partially or fully restricts, inhibits,
or blocks the channel (for
example, the bore 130 of the inflow-control apparatus 100) and partially or
fully prevents fluid
from flowing into the interior of the base pipe 14. In an embodiment, step 508
comprises providing
a steam volume fraction of at least 0.2 at an exit point of the inflow-control
apparatus 100, such
as for example, the second divergent end 136B, with a mass flow rate within a
predefined range.
Step 510: if the channel is not fully blocked, directing the fluid into the
base pipe 14. Those
skilled in the art will appreciate that the fluid directed into the base pipe
14 is a hydrocarbon-
enriched fluid as otherwise the water therein may be vaporized to steam and
block the channel. In
an embodiment, step 510 comprises discharging the hydrocarbon-enriched fluid
at the second
divergent end 136B of the inflow-control apparatus.
As those skilled in the art will appreciate, during SAGD or CSS operations,
the water
temperature at some spots (sometimes denoted as "hot spots") adjacent the base
pipe 14 is
relatively lower than the pre-set subcool temperature which is typically
defined and targeted at
about 10 C to 15 C lower than the saturation temperature at the bottom-hole
operating pressure.
.. Suitable inflow-control apparatuses 100 may be used at such hot spots to
prevent hot water or
following steam from entering the base pipe 14.
Those skilled in the art will also appreciate that the water distribution in
the subterranean
environment about the base pipe 14 is usually non-unifolin. Therefore, by
deploying a plurality
of inflow-control apparatuses 100 on the base pipe 14, the inflow-control
apparatuses 100 in the
.. water-rich zones may vaporize saturated and/or near saturated water to
partially or fully block the
water-rich fluid from entering the base pipe 14. On the other hand, the inflow-
control
apparatuses 100 in the hydrocarbon-rich zones (that is, with less or no water)
would generate little
or no steam and thus allow the hydrocarbon-rich fluid to enter the base pipe
14.
More specifically, in some situations, water and heated oil are not mixed as
emulsion and
.. may flow mainly separately from reservoir to the base pipe 14. In such
situations, the inflow-
14
Date Recue/Date Received 2023-09-13
control apparatus 100 may flash the saturated or near saturated water into a
steam-water-mixed
fluid (for example, a fluid containing more than 20% steam on volume basis) to
block the fluid
(which is water-rich) to enter the base pipe 14.
In some situations, the fluid may be a well-mixed emulsion such as an emulsion
of 50%
water and 50% oil. When the fluid flows through the inflow-control apparatus
100, the water
therein may be flashed into steam in a limited amount depending on how the
emulsion is formed.
Thus, the inflow-control apparatus 100 may mitigate the contained water by
flashing it into steam
to some extent while still allowing oil to flow therethough.
In some situations, the fluid may contain little or no water. Therefore,
little or no steam is
generated when the fluid passes through the inflow-control apparatus 100 and
subsequently the
fluid (which mainly or fully contains oil) flows through inflow-control
apparatus 100 into the base
pipe 14 for collection.
FIG. 8 shows a process 540 for collecting oil into a base pipe 14 with
controlled water
entrance, according to one embodiment of this disclosure. As shown, the
process 540 comprises:
Step 542: deploying the base pipe 14 (which may be a portion of a casing
string or a tubing
string) downhole into a well in a hydrocarbon reservoir.
Step 544: isolating a section of the well about the base pipe 14 using an
isolation device
such as a pair of packers.
Step 546: passing the fluid from the reservoir through at least one solids
filter.
Step 548: performing the inflow-control process 500 as described above.
Step 550: collecting hydrocarbon-enriched fluid in the base pipe 14.
FIG. 9 shows a plot of steam volume fraction (SVF) to mass flow rate for a
particular
embodiment of the inflow-control apparatus 100. Two different regions (Region
1 and Region 2)
and a Turning Point in a transition zone between the Region 1 and Region 2 may
be identified. As
can be seen, when mass flow rates of the flashed water are lower than a
certain first value (for
example, 0.06 kg/s) the profile of SVF versus mass flow rate shows an abrupt
increase with a
minimum slope of 10 from a lower mass flow rate. In contrast, when mass flow
rates of the flashed
water are higher than a certain second value, (for example, 0.07 kg/s), the
profile of SVF versus
mass flow rate turns into a much slower or near plateau. A turning point (for
example,
about 0.06 kg/s) between these two different regions may be located by
intersecting the two major
slopes of the two curves.
The inflow-control apparatus 100 of the present disclosure may operate in a
stable
operating condition with improved inflow control capabilities when the mass
flow rate exceeds a
threshold mass flow rate corresponding to the turning point. In some
embodiments, the inflow-
control apparatus 100 may be designed based on the main operating condition.
For example, in a
Date Recue/Date Received 2023-09-13
typical SAGD operation with the inflow-control apparatuses 100 installed, the
SAGD producer's
production rate may normally correspond to a wide range of 0.025 kg/s to 0.20
kg/s and may also
be specific to each well. Therefore, after the target threshold mass flow rate
is determined based
on the well condition, the dimensions of the inflow-control apparatus 100 may
be detettnined in
accordance with above-described ratios between the sections of the bore 130.
For example, in an
embodiment, the threshold mass flow rate of the inflow-control apparatus 100
may be between
about 0.025 kg/s to about 0.20 kg/s. In a particular embodiment, the threshold
mass flow rate of
the inflow-control apparatus 100 may be about 0.06 kg/s.
When a fluid flows through an inflow-control apparatus 100 of the present
disclosure, a
pressure drop may occur depending on the structure of the inflow-control
apparatus 100 and the
specific properties of the incoming fluid. As described above and will be
further described later,
the pressure drop of an unwanted fluid, for example undersaturated or
saturated water or injected
steam, comprises the pressure drop occurred in the convergent section 132 and
the throat
section 134, and the additional pressure drop occurred in the divergent
section 136.
To prevent or mitigate the unwanted fluid, for example undersaturated or
saturated water,
from entering the base pipe 14 and subsequently being produced to surface, the
different
characteristics of the undersaturated or saturated water in comparison to the
those of the heated
oil at downhole conditions may be utilized. When the undersaturated or
saturated water flows
through the inflow-control apparatus 100 of the present disclosure, the
pressure drop may cause a
considerable amount of steam to flash out of the water (that is, in the liquid
phase) into the vapor
(that is, in the gas phase), or cause a substantial expansion of the volume of
the injected steam.
The suddenly appearing vapor phase and/or significantly increased volume of
the vapor phase
may fill the central bore 130 and result in a further increase of the pressure
drop across the inflow-
control apparatus 100. Generally, the pressure drops caused by various reasons
leads to
vaporization of water and the generated steam or the expansion of the injected
steam may partially
or fully prevent the fluid (which is generally a water-rich fluid) from
entering the base pipe 14.
"Cavitation" or "flashing" occurs when the static pressure of a liquid reduces
to below the
liquid's vapor pressure, leading to the formation of small vapor-filled
cavities in the liquid. When
the undersaturated or saturated water or a mixture of water and steam/vapor
passes through the
inflow-control apparatus 100, hydrodynamic cavitation may be produced.
The level of cavitation typically depends on the geometry of the inflow-
control
apparatus 100, environmental conditions (such as pressure and/or temperature),
the characteristics
of the injected fluid, the injection rate, and/or the like. A lower level of
cavitation may generate a
slight increase of pressure drop across the inflow-control apparatus 100 due
to a partial restriction
16
Date Recue/Date Received 2023-09-13
of the fluid flow. On other hand, a higher level of cavitation may create a
sharp increase of pressure
drop as the flashed vapor bubbles block a large area of the bore 130.
When the velocity of the flashed vapor in inflow-control apparatus 100 reaches
the local
sonic speed in the flow medium (that is, the speed of an acoustic wave at a
particular location in
the flow medium), "supercavitation" condition is developed, which means that
the bore 130 of the
inflow-control apparatus 100 is "choked" and is not capable of passing more
flow (for example,
the velocity of the fluid flow does not increase while the pressure at the
outlet 136B of the inflow-
control apparatus 100 further decreases). In a two-phase liquid-vapor mixture
system, the sonic
speed is much smaller than that in the pure steam/vapor or pure water. This is
mainly because of
the heat and mass transfer between the phases to maintain theimal equilibrium
and the generated
vaporization waves when a liquid is converted to a vapor. Therefore, in a
typical SAGD operation,
when unwanted fluids such as the undersaturated or saturated water and
steam/vapor flow through
the downhole inflow-control apparatus, the supercavitation or choke condition
is relatively easy
to achieve in comparison to flowing pure water or pure steam/vapor through an
inflow-control
apparatus 100.
On the other hand, when the heated oil flows through the inflow-control
apparatus 100 of
the present disclosure, the pressure drop is much lower than that that of the
undersaturated or
saturated water since there is substantially no oil-vapor or gas-phase oil
flashed out of the liquid-
phase oil. Therefore, a hydrocarbon-rich fluid will not be prevented or
mitigated from entering the
base pipe 14 and being produced to surface.
The structure and dimensions of the inflow-control apparatus 100 of the
present disclosure
advantageously allows for both fluid mechanics and theimodynamic theories to
take place to
provide a sufficiently high pressure drop when a fluid containing water flows
through and thus
flash out a significant volume of steam from water for blocking the fluid to
enter the base pipe 14,
thereby selectively blocking water-rich and/or steam-rich fluids and allowing
hydrocarbon-rich
fluid to flow into the base pipe 14.
In particular, when the undersaturated water flows through the convergent
section 132
from the cross-section A to cross-section Bi (see FIG. 10), the Bernoulli
effect from fluid
mechanics theory takes into effect (see Equation (1)).
1 , 1
PA +PV+ P911,1= PB1 P
2. + P9 hBi + Hfriction A-B1 (1)
wherein PA represents the fluid average pressure at cross-section A, p
represents the fluid density,
VA represents the fluid average velocity at cross-section A, vBi represents
the fluid average velocity
at cross-section Bi, g represents the standard gravity, hA represents the
height at cross-section A
above a reference plane (for example, cross-section C), hB represents the
height at cross-section
17
Date Recue/Date Received 2023-09-13
B1 above a reference plane (for example, cross-section C), P.B/ represents the
fluid average
pressure at cross-section Bi, and Hfi'lCtiOff A-RI represents the friction
loss in energy.
More specifically, as the cross-section area is continuously reduced from A to
Bi, the
velocity of the undersaturated water at cross-section Bi is much larger than
that at cross-section A,
that is, 1,81 > VA. Since the position difference and friction loss from A to
Bi may be negligible,
the pressure of cross-section Bi is significantly lower than that of cross-
section A, that is,
PB1 < PA-
For example, as the pressure of undersaturated water is reduced from cross-
section A to
Bi, the water saturation temperature is correspondingly reduced. Therefore, at
cross-section Bi,
the physical state of the flowing water may be located in the transition zone,
which is a mixture
of water and steam. This phenomenon is shown as Point A and Point B1 in the
Pressure-
Temperature Phase Equilibrium Diagram in FIG. 11. When plotting Point A and
Point Bi in the
Pressure-Enthalpy Phase Equilibrium diagram, they may typically be located as
shown in FIG. 12.
As the energy loss from Point A to Bi is very small, the total enthalpy of the
mixture at Point Bi
is only slightly lower than that of the undersaturated water at Point A, that
is, HB1 < HA. More
importantly, a certain amount of steam may be flashed out from the water phase
in this situation.
Because the steam mass quality (or dryness) may be any value between 0% and
100% in the
transition zone, the steam mass quality of the mixed water and steam (that is,
a wet steam) mainly
depends on the enthalpy of the incoming undersaturated water at Point A and
pressure and
temperature at Point Bi.
In the throat section 134, the physical state and carried enthalpy of the
mixed water and
steam only have minor changes, which leads to TBI TB2 as shown in FIG. 11 and
HBI HB2 as
exemplified in FIG. 12. When the mixed water and steam (wet steam) flow
through the divergent
section 136 from the cross-section B2 to cross-section C in a suitable
divergent angle
corresponding to the specific viscosity of the fluid, the mixed water and
steam will expand their
volume while conforming to the wall of the divergent section 136. In this
expansion process, the
mixed water and steam conduct work to the surrounding environment of the bore
130, as shown
in Equation (2) below. Meanwhile, the carried total enthalpy, temperature,
and/or pressure may
decrease in terms of the energy balance theory from the first law of
thermodynamics.
vc
W = PdV (2)
vB,
wherein Wrepresents the work conducted by the mixed water and steam, P
represents the pressure
of the mixed water and steam, VB2 represents the volume of the mixed water and
steam at cross-
section B2, and Vc represents the volume of the mixed water and steam at cross-
section C. The
pressure at cross-section C can be smaller, equal to, or higher than that at
cross-section B2.
18
Date Recue/Date Received 2023-09-13
For example, in FIG. 11, the temperature of Point C may be lower than that of
Point B2 in
comparison to the process occurred in convergent section 132 from Point A to
Point Bi, where the
temperature of Point Bi is only slightly lower or very close to that of Point
A. Correspondingly,
in FIG. 12, the enthalpy of Point C may be substantially lower than that of
Point B2 in comparison
to the process occurred in the convergent section 132 from Point A to Point
Bi. In the divergent
zone 134, the mixture may flash out more steam from water at a relatively
lower pressure and
temperature conditions. As shown in FIG. 12, steam mass quality at Point C is
higher than that at
Point B2. In the inflow-control apparatus 100 of the present disclosure, it
may increase the steam
mass quality at the interior end to near, at, or above (for example, doubling)
that at the exterior
end, which is equivalent to a similar rate of increase of the steam volume
fraction under typical
SAGD operating conditions.
Thus, when flowing through the central bore 130 of the inflow-control
apparatus 100
disclosed herein, undersaturated or saturated unwanted fluid (for example,
water or steam) may
experience significant pressure drop and flash out a substantial amount of
steam, or experience a
substantial expansion of its volume thereby mitigating unwanted fluid (for
example, water or
steam) being produced to surface.
FIG. 13 shows a plot of pressure drop to mass flow rate for a particular
embodiment of the
inflow-control apparatus 100. At the same mass flow rate, the pressure drop of
the flashed water
across the apparatus 100 will be higher than that of hypothetical water which
has the same
properties as pure liquid water at the same temperature and pressure condition
but without flashing
capabilities (that is, "the hypothetical liquid"). In an embodiment, at the
same mass flow rate, the
pressure drop of the flashed water across the inflow-control apparatus 100 is
at least about 20%
higher than that of a heated heavy oil under typical SAGD or CSS downhole
conditions. In an
embodiment, the general slope of pressure drop to mass flow rate of the
flashed water using the
inflow-control apparatus 100 is equal to or greater than that of the pressure
drop to mass flow rate
of the hypothetical liquid.
As mentioned above, the inflow-control apparatus 100 of the present disclosure
may
provide an environment for flashed vapor from the water phase to conform to
the wall of the
divergent zone 136. An exemplary model image of this conformance is shown in
FIG. 14A. The
conformance to the wall of the divergent zone 136 indicates that the flashed
steam dominates the
whole flow. In contrast, FIG. 14B shows the mainstream of flashed vapor from
the water phase
detaching from the wall in an inflow-control apparatus that does not have the
features of the
inflow-control apparatus of the present disclosure, indicative that the steam
volume fraction is
decreasing, flattening, or not increasing as significantly as that created
from the present disclosure.
19
Date Recue/Date Received 2023-09-13
Experimental tests have been performed on an inflow-control apparatus 100 of
an
exemplary geometry (denoted "Geometry 5" hereinafter), wherein the ID Dc of
the convergent
section 132 and the ID DT of the throat section 134 are in a ratio of 1.67:1,
and the ID DD of the
divergent section 136 and the ID DT of the throat section 134 are also in a
ratio of 1.67:1.
In the experimental tests, the mass flow rate is targeted at 0.15 kg/s, the
temperature at the
inlet 120 of the inflow-control apparatus 100 is 220 C, the pressure at the
inlet 120 of the inflow-
control apparatus 100 is pre-calculated according to different subcool
conditions and the specific
steam quality shown in Table 1 below. The pressure at the outlet 136B of the
inflow-control
apparatus 100 is adjusted to reach the targeted mass flow rate of 0.15 kg/s.
The unwanted fluids,
for example, the undersaturated or saturated water and steam/vapor, are chosen
as the testing fluid
in the experimental tests.
Table 1 Testing Conditions for Geometry 5
C subcool
10 C subcool
5 C subcool
1 C subcool
0 C subcool
Steam quality = 1% mass fraction
Steam quality = 2% mass fraction
Steam quality = 2.2% mass fraction (choked)
FIG. 15A shows the pressure differences between the inlet 120 and outlet 136B
of the
15 inflow-
control apparatus 100 under different testing conditions shown in Table 1. As
can be seen,
the pressure drop (Delta P) between the inlet 120 and outlet 136B of the
inflow-control
apparatus 100 increases as the temperature at the inlet 120 approaches the
saturation temperature
of water at the specific inlet pressure of the inflow-control apparatus 100.
The Delta P increases
more significantly as a certain amount of steam vapor, such as 1% and 2% steam
quality (mass
20
fraction), is injected with the saturated water. When the steam quality is
increased to 2.2% mass
fraction or higher, the injected fluid (saturated water and steam/vapor) is
"choked", which means
that at higher than 2.2% steam quality, the targeted mass flow rate of the
injected fluid, which
is 0.15kg/s in this case, cannot be achieved regardless how much lower the
outlet pressure of the
inflow-control apparatus 100 is decreased thereto.
In a practical SAGD operation, the above-mentioned experimental performance of
the
inflow-control apparatus 100 may be achieved in the following situations.
Date Recue/Date Received 2023-09-13
1) At normal or sufficient subcool conditions, the pressure drop (Delta P)
between the
inlet 120 and outlet 136B of the inflow-control apparatus 100 may be
relatively small when having
a highly subcooled water (such as greater than or equal to 20 C subcool) or
hydrocarbon passing
through the inflow-control apparatus 100.
2) As hot spots developing in certain locations along the horizontal wellbore
due to
reservoir heterogeneity or pressure loss through the wellbore, these hot spots
may encounter a
much lower subcool of the coming undersaturated or saturated water. In this
case, the installed
downhole inflow-control apparatus 100 may create larger pressure drops in
these hot spots to
inhibit the unwanted fluid while enhancing the production of the wanted fluid,
for example,
oil/hydrocarbon from other cold regions.
3) Some severe hot-spots may encounter the breakthrough of saturated water
mixed with
a certain amount of steam. In this case, the inflow-control apparatus 100 may
yield a substantially
high pressure drop to restrict the flow of the unwanted fluid. At the choke
condition, the mass
flow of the unwanted fluid reaches the upper limit or supercavitation
condition of the inflow-
control device regardless how much more drawdown pressure the downhole pump
creates. In this
case, by applying large drawdown pressure by downhole pumps, the oil
production may be further
enhanced from the cold regions of the reservoir while the inflow-control
apparatuses 100 restrict
the flow of the unwanted fluid from the hot spots.
FIG.15B shows the steam volume fraction at the inlet 120 and outlet 136B of
the inflow-
.. control apparatus 100. As shown, when the subcool temperature of the
injected water is 5 C or
lower, the steam volume fraction (SVF) increases as the inlet temperature of
the inflow-control
apparatus 100 approaches the saturation temperature of the water at the
specific inlet pressure.
The SVF at the outlet 136B of the inflow-control apparatus 100 is much larger
than that at the
inlet 120 thereof when the injected water has a low subcool-temperature or
contains saturated
.. water mixed with a certain amount of steam. The difference between the
inlet and outlet SVF
becomes larger as steam quality increases in the injected fluid. The results
show that flashing or
cavitation and/or expansion has occurred at the testing conditions to create
the additional pressure
drop when the unwanted fluid passes through the inflow-control apparatus 100.
In above embodiments, the inflow-control apparatuses 100 are coupled to the
base pipe 14
via suitable connections. In one embodiment, the inflow-control apparatuses
100 are integrated
with the base pipe 14. In another embodiment as shown in FIGs. 19A and 19B,
the inflow-control
apparatuses 100 are manufactured on the base pipe 14. More specifically, the
base pipe 14 in this
embodiment may comprise a plurality of ports 120 with the inner wall of each
port 120 being
formed with the convergent section 132, the throat section 134, and the
divergent section 136
between the exterior end 110A and interior end 110B as described above.
21
Date Recue/Date Received 2023-09-13
In an embodiment wherein the base pipe 14 comprises a plurality of ports 120
and thus a
plurality of inflow-control apparatuses 100, the plurality of inflow-control
apparatuses 100 may
be spaced apart around the circumference of the base pipe 14. In another
embodiment, the plurality
of inflow-control apparatuses 100 may be longitudinally distributed on the
sidewall of the base
pipe 14. In yet another embodiment, the plurality of inflow-control
apparatuses 100 may be
positioned around the circumference of the base pipe 14 and longitudinally
distributed on the
sidewall of the base pipe 14. In an embodiment, the spacing is chosen to more
evenly distribute
wellbore pressure. The spacing may be of any suitable distance along the
longitudinal direction of
the base pipe 14 and may be unifoun spacing or non-uniform spacing as needed.
FIG. 16 shows an inflow-control apparatus 100 according to an alternative
embodiment of
this disclosure, which is similar to the inflow-control apparatus 100 shown in
FIGs. 3A to 3C
except that the inflow-control apparatus 100 in this embodiment does not
comprise any inlet on
the side of the head portion. Rather, the inflow-control apparatus 100 in this
embodiment
comprises an inlet 120 on the end wall on the exterior side thereof.
FIG. 17 shows an inflow-control apparatus 100 according to an alternative
embodiment of
this disclosure, which is similar to the inflow-control apparatus 100 shown in
FIG. 16 except that
the inflow-control apparatus 100 in this embodiment has a uniform OD.
FIG. 18 shows the base pipe 14 with the solids filter 220 and the housing 232
enclosing
therein a plurality of inflow-control apparatuses 100 shown in FIG. 17. The
base pipe 14 is similar
to that shown in FIGs. 5C and 5D, except that the ports 210 are at an angle
(that is, nn-
perpendicular) to the sidewall 212, and the inflow-control apparatuses 100 are
received in the
ports 210 also at an angle to the sidewall 212 for reducing the profile of the
inflow-control
apparatuses 100 on the base pipe 14.
Although embodiments have been described above with reference to the
accompanying
drawings, those of skill in the art will appreciate that variations and
modifications may be made
without departing from the scope thereof as defined by the appended claims.
22
Date Recue/Date Received 2023-09-13
