SELECTIVELY VARIABLE FLOW RESTRICTOR
FOR USE IN A SUBTERRANEAN WELL
TECHNICAL FIELD
This disclosure relates generally to equipment utilized
and operations performed in conjunction with a subterranean
well and, in an example described below, more particularly
provides a selectively variable flow restrictor.
BACKGROUND
In a hydrocarbon production well, it is many times
beneficial to be able to regulate flow of fluids from an
earth formation into a wellbore, from the wellbore into the
formation, and within the wellbore. A variety of purposes
may be served by such regulation, including prevention of
water or gas coning, minimizing sand production, minimizing
water and/or gas production, maximizing oil production,
balancing production among zones, transmitting signals, etc.
Therefore, it will be appreciated that advancements in
the art of variably restricting fluid flow in a well would
be desirable in the circumstances mentioned above, and such
advancements would also be beneficial in a wide variety of
other circumstances.
SUMMARY
In the disclosure below, a variable flow resistance
system is provided which brings improvements to the art of
variably restricting fluid flow in a well. Examples are
described below in which the flow is selectively restricted
for various purposes.
In one aspect, a variable flow resistance system for
use with a subterranean well is provided to the art. The
system can include a flow chamber through which a fluid
composition flows, the chamber having at least two inlet
flow paths, and a flow resistance which varies depending on
proportions of the fluid composition which flow into the
chamber via the respective inlet flow paths. An actuator
deflects the fluid composition toward one of the inlet flow
paths.
In another aspect, a method of variably controlling
flow resistance in a well is described below. The method can
include changing an orientation of a deflector relative to a
passage through which a fluid composition flows, thereby
influencing the fluid composition to flow toward one of
multiple inlet flow paths of a flow chamber, the chamber
having a flow resistance which varies depending on
proportions of the fluid composition which flow into the
chamber via the respective inlet flow paths.
These and other features, advantages and benefits will
become apparent to one of ordinary skill in the art upon
careful consideration of the detailed description of
representative examples below and the accompanying drawings,
in which similar elements are indicated in the various
figures using the same reference numbers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a representative partially cross-sectional
view of a well system which can embody principles of this
disclosure .
FIG. 2 is a representative enlarged scale crosssectional
view of a portion of the well system.
FIG. 3 is a representative cross-sectional view of a
variable flow resistance system which can be used in the
well system, the variable flow resistance system embodying
principles of this disclosure, with flow through the system
being relatively unrestricted.
FIG. 4 is a representative cross-sectional view of the
variable flow resistance system, with flow through the
system being relatively restricted.
FIG. 5 is a representative cross-sectional view of
another configuration of the variable flow resistance
system, with flow through the system being relatively
restricted.
FIG. 6 is a representative cross-sectional view of the
FIG. 5 configuration of the variable flow resistance system,
with flow through the system being relatively unrestricted.
FIGS. 7-11 are representative diagrams of actuator
configurations which may be used in the variable flow
resistance system.
FIG. 12 is a representative graph of pressure or flow
versus time in a method which can embody principles of this
disclosure .
FIG. 13 is a representative partially cross-sectional
view of the method being used for transmitting signals from
the variable flow resistance system to a remote location.
DETAILED DESCRIPTION
Representatively illustrated in FIG. 1 is a well system
10 which can embody principles of this disclosure. As
depicted in FIG. 1 , a wellbore 12 has a generally vertical
uncased section 14 extending downwardly from casing 16, as
well as a generally horizontal uncased section 18 extending
through an earth formation 20.
A tubular string 22 (such as a production tubing
string) is installed in the wellbore 12. Interconnected in
the tubular string 22 are multiple well screens 24, variable
flow resistance systems 25 and packers 26.
The packers 26 seal off an annulus 28 formed radially
between the tubular string 22 and the wellbore section 18.
In this manner, fluids 30 may be produced from multiple
intervals or zones of the formation 20 via isolated portions
of the annulus 28 between adjacent pairs of the packers 26.
Positioned between each adjacent pair of the packers
26, a well screen 24 and a variable flow resistance system
25 are interconnected in the tubular string 22. The well
screen 24 filters the fluids 30 flowing into the tubular
string 22 from the annulus 28. The variable flow resistance
system 25 variably restricts flow of the fluids 30 into the
tubular string 22, based on certain characteristics of the
fluids and/or based on operation of an actuator thereof (as
described more fully below) .
At this point, it should be noted that the well system
10 is illustrated in the drawings and is described herein as
merely one example of a wide variety of well systems in
which the principles of this disclosure can be utilized. It
should be clearly understood that the principles of this
disclosure are not limited at all to any of the details of
the well system 10, or components thereof, depicted in the
drawings or described herein.
For example, it is not necessary in keeping with the
principles of this disclosure for the wellbore 12 to include
a generally vertical wellbore section 14 or a generally
horizontal wellbore section 18. It is not necessary for
fluids 30 to be only produced from the formation 20 since,
in other examples, fluids could be injected into a
formation, fluids could be both injected into and produced
from a formation, etc.
It is not necessary for one each of the well screen 24
and variable flow resistance system 25 to be positioned
between each adjacent pair of the packers 26. It is not
necessary for a single variable flow resistance system 25 to
be used in conjunction with a single well screen 24. Any
number, arrangement and/or combination of these components
may be used.
It is not necessary for any variable flow resistance
system 25 to be used with a well screen 24. For example, in
injection operations, the injected fluid could be flowed
through a variable flow resistance system 25, without also
flowing through a well screen 24.
It is not necessary for the well screens 24, variable
flow resistance systems 25, packers 26 or any other
components of the tubular string 22 to be positioned in
uncased sections 14, 18 of the wellbore 12. Any section of
the wellbore 12 may be cased or uncased, and any portion of
the tubular string 22 may be positioned in an uncased or
cased section of the wellbore, in keeping with the
principles of this disclosure.
It should be clearly understood, therefore, that this
disclosure describes how to make and use certain examples,
but the principles of the disclosure are not limited to any
details of those examples. Instead, those principles can be
applied to a variety of other examples using the knowledge
obtained from this disclosure.
It will be appreciated by those skilled in the art that
it would be beneficial to be able to regulate flow of the
fluids 30 into the tubular string 22 from each zone of the
formation 20, for example, to prevent water coning 32 or gas
coning 34 in the formation. Other uses for flow regulation
in a well include, but are not limited to, balancing
production from (or injection into) multiple zones,
minimizing production or injection of undesired fluids,
maximizing production or injection of desired fluids,
transmitting signals, etc.
In examples described below, resistance to flow through
the systems 25 can be selectively varied, on demand and/or
in response to a particular condition. For example, flow
through the systems 25 could be relatively restricted while
the tubular string 22 is installed, and during a gravel
packing operation, but flow through the systems could be
relatively unrestricted when producing the fluid 30 from the
formation 20. As another example, flow through the systems
25 could be relatively restricted at elevated temperature
indicative of steam breakthrough in a steam flooding
operation, but flow through the systems could be relatively
unrestricted at reduced temperatures.
An example of the variable flow resistance systems 25
described more fully below can also increase resistance to
flow if a fluid velocity or density increases (e.g., to
thereby balance flow among zones, prevent water or gas
coning, etc.), or increase resistance to flow if a fluid
viscosity decreases (e.g., to thereby restrict flow of an
undesired fluid, such as water or gas, in an oil producing
well). Conversely, these variable flow resistance systems 2 5
can decrease resistance to flow if fluid velocity or density
decreases, or if fluid viscosity increases.
Whether a fluid is a desired or an undesired fluid
depends on the purpose of the production or injection
operation being conducted. For example, if it is desired to
produce oil from a well, but not to produce water or gas,
then oil is a desired fluid and water and gas are undesired
fluids.
Note that, at downhole temperatures and pressures,
hydrocarbon gas can actually be completely or partially in
liquid phase. Thus, it should be understood that when the
term "gas" is used herein, supercritical, liquid and/or
gaseous phases are included within the scope of that term.
Referring additionally now to FIG. 2 , an enlarged scale
cross-sectional view of one of the variable flow resistance
systems 2 5 and a portion of one of the well screens 2 4 is
representatively illustrated. In this example, a fluid
composition 3 6 (which can include one or more fluids, such
as oil and water, liquid water and steam, oil and gas, gas
and water, oil, water and gas, etc.) flows into the well
screen 2 4 , is thereby filtered, and then flows into an inlet
3 8 of the variable flow resistance system 2 5 .
A fluid composition can include one or more undesired
or desired fluids. Both steam and water can be combined in a
fluid composition. As another example, oil, water and/or gas
can be combined in a fluid composition.
Flow of the fluid composition 3 6 through the variable
flow resistance system 2 5 is resisted based on one or more
characteristics (such as viscosity, velocity, density, etc.)
of the fluid composition. The fluid composition 3 6 is then
discharged from the variable flow resistance system 25 to an
interior of the tubular string 22 via an outlet 40.
In other examples, the well screen 24 may not be used
in conjunction with the variable flow resistance system 25
(e.g., in injection operations), the fluid composition 36
could flow in an opposite direction through the various
elements of the well system 10 (e.g., in injection
operations), a single variable flow resistance system could
be used in conjunction with multiple well screens, multiple
variable flow resistance systems could be used with one or
more well screens, the fluid composition could be received
from or discharged into regions of a well other than an
annulus or a tubular string, the fluid composition could
flow through the variable flow resistance system prior to
flowing through the well screen, any other components could
be interconnected upstream or downstream of the well screen
and/or variable flow resistance system, etc. Thus, it will
be appreciated that the principles of this disclosure are
not limited at all to the details of the example depicted in
FIG. 2 and described herein.
Although the well screen 24 depicted in FIG. 2 is of
the type known to those skilled in the art as a wire-wrapped
well screen, any other types or combinations of well screens
(such as sintered, expanded, pre-packed, wire mesh, etc.)
may be used in other examples. Additional components (such
as shrouds, shunt tubes, lines, instrumentation, sensors,
inflow control devices, etc.) may also be used, if desired.
The variable flow resistance system 25 is depicted in
simplified form in FIG. 2 , but in a preferred example, the
system can include various passages and devices for
performing various functions, as described more fully below.
In addition, the system 25 preferably at least partially
extends circumf erentially about the tubular string 2 2 , or
the system may be formed in a wall of a tubular structure
interconnected as part of the tubular string.
In other examples, the system 2 5 may not extend
circumf erentially about a tubular string or be formed in a
wall of a tubular structure. For example, the system 2 5
could be formed in a flat structure, etc. The system 2 5
could be in a separate housing that is attached to the
tubular string 2 2 , or it could be oriented so that the axis
of the outlet 4 0 is parallel to the axis of the tubular
string. The system 2 5 could be on a logging string or
attached to a device that is not tubular in shape. Any
orientation or configuration of the system 2 5 may be used in
keeping with the principles of this disclosure.
Referring additionally now to FIG. 3 , a cross-sectional
view of the variable flow resistance system 2 5 , taken along
line 3-3 of FIG. 2 , is representatively illustrated. The
variable flow resistance system 2 5 example depicted in FIG.
3 may be used in the well system 1 0 of FIGS. 1 & 2 , or it
may be used in other well systems in keeping with the
principles of this disclosure.
In FIG. 3 , it may be seen that the fluid composition 3 6
flows from the inlet 3 8 to the outlet 4 0 via passage 4 4 ,
inlet flow paths 4 6 , 4 8 and a flow chamber 5 0 . The flow
paths 4 6 , 4 8 are branches of the passage 4 4 and intersect
the chamber 5 0 at inlets 5 2 , 5 4 .
Although in FIG. 3 the flow paths 4 6 , 4 8 diverge from
the inlet passage 4 4 by approximately the same angle, in
other examples the flow paths 4 6 , 4 8 may not be symmetrical
with respect to the passage 4 4 . For example, the flow path
4 8 could diverge from the inlet passage 4 4 by a smaller
angle as compared to the flow path 4 6 , so that, when an
actuator member 6 2 is not extended (as depicted in FIG. 3 ) ,
more of the fluid composition 3 6 will flow through the flow
path 4 8 to the chamber 5 0 .
As depicted in FIG. 3 , more of the fluid composition 3 6
does enter the chamber 5 0 via the flow path 4 8 , due to the
well-known Coanda or "wall" effect. However, in other
examples, the fluid composition 3 6 could enter the chamber
5 0 substantially equally via the flow paths 4 6 , 4 8 .
A resistance to flow of the fluid composition 3 6
through the system 2 5 depends on proportions of the fluid
composition which flow into the chamber via the respective
flow paths 4 6 , 4 8 and inlets 5 2 , 5 4 . As depicted in FIG. 3 ,
approximately half of the fluid composition 3 6 flows into
the chamber 5 0 via the flow path 4 6 and inlet 5 2 , and about
half of the fluid composition flows into the chamber via the
flow path 4 8 and inlet 5 4 .
In this situation, flow through the system 2 5 is
relatively unrestricted. The fluid composition 3 6 can
readily flow between various structures 5 6 in the chamber 5 0
en route to the outlet 4 0 .
Referring additionally now to FIG. 4 , the system 2 5 is
representatively illustrated in another configuration, in
which flow resistance through the system is increased, as
compared to the configuration of FIG. 3 . Preferably, this
increase in flow resistance of the system 2 5 is not due to a
change in a property of the fluid composition 3 6 (although
in other examples the flow resistance increase could be due
to a change in a property of the fluid composition) .
As depicted in FIG. 4 , a deflector 5 8 has been
displaced relative to the passage 4 4 , so that the fluid
composition 3 6 is influenced to flow more toward the branch
flow path 4 6 . A greater proportion of the fluid composition
3 6 , thus, flows through the flow path 4 6 and into the
chamber 5 0 via the inlet 5 2 , as compared to the proportion
which flows into the chamber via the inlet 5 4 .
When a majority of the fluid composition 3 6 flows into
the chamber 5 0 via the inlet 5 2 , the fluid composition tends
to rotate counter-clockwise in the chamber (as viewed in
FIG. 4 ) . The structures 5 6 are designed to promote such
rotational flow in the chamber 5 0 , and as a result, more
energy in the fluid composition 3 6 flow is dissipated. Thus,
resistance to flow through the system 2 5 is increased in the
FIG. 4 configuration as compared to the FIG. 3
configuration .
In this example, the deflector 5 8 is displaced by an
actuator 6 0 . Any type of actuator may be used for the
actuator 6 0 . The actuator 6 0 may be operated in response to
any type of stimulus (e.g., electrical, magnetic,
temperature, etc.).
In other examples, the deflector 5 8 could move in
response to erosion or corrosion of the deflector (i.e., so
that its surface is moved) . In another example, the
deflector 5 8 could be a sacrificial anode in a galvanic
cell. In another example, the deflector 5 8 could move by
being dissolved (e.g., with the deflector being made of salt
, polylactic acid, etc.). In yet another example, the
deflector 5 8 could move by deposition on its surface (such
as, from scale, asphaltenes, paraffins, etc., or from
galvanic deposition as a protected cathode).
Although it appears in FIG. 4 that a member 6 2 of the
actuator 6 0 has moved to thereby displace the deflector 5 8 ,
in other examples the deflector can be displaced without
moving an actuator member from one position to another. The
member 6 2 could instead change configuration (e.g.,
elongating, retracting, expanding, swelling, etc.), without
necessarily moving from one position to another.
Although in FIGS. 3 & 4 the flow chamber 50 has
multiple inlets 52, 54, any number (including one) of inlets
may be used in keeping with the scope of this disclosure.
For example, in U.S. application serial no. 12/792117, filed
on 2 June 2010, a flow chamber is described which has only a
single inlet, but resistance to flow through the chamber
varies depending on via which flow path a majority of a
fluid composition enters the chamber.
Another configuration of the variable flow resistance
system is representatively illustrated in FIGS. 5 & 6 . In
this configuration, flow resistance through the system 25
can be varied due to a change in a property of the fluid
composition 36, or in response to a particular condition or
stimulus using the actuator 60.
In FIG. 5 , the fluid composition 36 has a relatively
high velocity. As the fluid composition 36 flows through the
passage 44, it passes multiple chambers 64 formed in a side
of the passage. Each of the chambers 64 is in communication
with a pressure-operated fluid switch 66.
At elevated velocities of the fluid composition 36 in
the passage 44, a reduced pressure will be applied to the
fluid switch 66 as a result of the fluid composition flowing
past the chambers 64, and the fluid composition will be
influenced to flow toward the branch flow path 48, as
depicted in FIG. 5 . A majority of the fluid composition 36
flows into the chamber 50 via the inlet 54, and flow
resistance through the system 25 is increased. At lower
velocities and increased viscosities, more of the fluid
composition 36 will flow into the chamber 50 via the inlet
52, and flow resistance through the system 25 is decreased
due to less rotational flow in the chamber.
In FIG. 6 , the actuator 60 has been operated to deflect
the fluid composition 36 from the passage 44 toward the
branch flow path 46. Rotational flow of the fluid
composition 36 in the chamber 50 is reduced, and the
resistance to flow through the system 25 is, thus, also
reduced.
Note that, if the velocity of the fluid composition 36
in the passage 44 is reduced, or if the viscosity of the
fluid composition is increased, a portion of the fluid
composition can flow into the chambers 64 and to the fluid
switch 66, which also influences the fluid composition to
flow more toward the flow path 46. However, preferably the
movement of the deflector 58 is effective to direct the
fluid composition 36 to flow toward the flow path 46,
whether or not the fluid composition flows to the fluid
switch 66 from the chambers 64.
Referring additionally now to FIGS. 7-11, examples of
various configurations of the actuator 60 are
representatively illustrated. The actuators 60 of FIGS. 7-11
may be used in the variable flow resistance system 25, or
they may be used in other systems in keeping with the
principles of this disclosure.
In FIG. 7 , the actuator 60 comprises the member 62
having the deflector 58 formed thereon, or attached thereto.
The member 62 comprises a material 68 which changes shape or
moves in response to an electrical signal or stimulus from a
controller 70. Electrical power may be supplied to the
controller 70 by a battery 72 or another source (such as an
electrical generator, etc.).
A sensor or detector 7 4 may be used to detect a signal
transmitted to the actuator 6 0 from a remote location (such
as the earth's surface, a subsea wellhead, a rig, a
production facility, etc.). The signal could be a telemetry
signal transmitted by, for example, acoustic waves, pressure
pulses, electromagnetic waves, vibrations, pipe
manipulations, etc. Any type of signal may be detected by
the detector 7 4 in keeping with the principles of this
disclosure .
The material 6 8 may be any type of material which can
change shape or move in response to application or
withdrawal of an electrical stimulus. Examples include
piezoceramics , piezoelectrics , electrostrictors , etc. A
pyroelectric material could be included, in order to
generate electricity in response to a particular change in
temperature .
The electrical stimulus may be applied to deflect the
fluid composition 3 6 toward the branch flow path 4 6 , or to
deflect the fluid composition toward the branch flow path
4 8 . Alternatively, the electrical stimulus may be applied
when no deflection of the fluid composition 3 6 by the
deflector 5 8 is desired.
In FIG. 8 , the member 6 2 comprises the material 6 8
which, in this configuration, changes shape or moves in
response to a magnetic signal or stimulus from the
controller 7 0 . In this example, electrical current supplied
by the controller 7 0 is converted into a magnetic field
using a coil 7 6 , but other techniques for applying a
magnetic field to the material 6 8 (e.g., permanent magnets,
etc.) may be used, if desired.
The material 6 8 in this example may be any type of
material which can change shape or move in response to
application or withdrawal of a magnetic field. Examples
include magnetic shape memory materials, magnetostrictors ,
permanent magnets, ferromagnetic materials, etc.
In one example, the member 6 2 and coil 7 6 could
comprise a voice coil or a solenoid. The solenoid could be a
latching solenoid. In any of the examples described herein,
the actuator 6 0 could be bi-stable and could lock into the
extended and/or retracted configurations.
The magnetic field may be applied to deflect the fluid
composition 3 6 toward the branch flow path 4 6 , or to deflect
the fluid composition toward the branch flow path 4 8 .
Alternatively, the magnetic field may be applied when no
deflection of the fluid composition 3 6 by the deflector 5 8
is desired.
In FIG. 9 , the deflector 5 8 deflects the fluid
composition 3 6 which flows through the passage 4 4 . In one
example, the deflector 5 8 can displace relative to the
passage 4 4 due to erosion or corrosion of the member 6 2 .
This erosion or corrosion could be due to human intervention
(e.g., by contacting the member 6 2 with a corrosive fluid),
or it could be due to passage of time (e.g., due to flow of
the fluid composition 3 6 over the member 6 2 ) .
In another example, the member 6 2 can be made to
relatively quickly corrode by making it a sacrificial anode
in a galvanic cell. An electrolyte fluid 7 8 could be
selectively introduced into a passage 8 0 (such as, via a
line extending to a remote location, etc.) exposed to the
material 6 8 , which could be less noble as compared to
another material 8 2 also exposed to the fluid.
The member 6 2 could grow due to galvanic deposition on
its surface if, for example, the member is a protected
cathode in the galvanic cell. The member 6 2 could, in other
examples, grow due to deposition of scale, asphaltenes,
paraffins, etc. on the member.
In yet another example, the material 68 could be
swellable, and the fluid 78 could be a type of fluid which
causes the material to swell (i.e., increase in volume).
Various materials are known (e.g., see U.S. Patent Nos.
3385367 and 7059415, and U.S. Publication Nos. 2004-0020662
and 2007-0257405) which swell in response to contact with
water, liquid hydrocarbons and/or gaseous or supercritical
hydrocarbons. Alternatively, the material 68 could swell in
response to the fluid composition 36 comprising an increased
ratio of desired fluid to undesired fluid, or an increased
ratio of undesired fluid to desired fluid.
In a further example, the material 68 could swell in
response to a change in ion concentration (such as a pH of
the fluid 78, or of the fluid composition 36). For example,
the material 68 could comprise a polymer hydrogel.
In yet another example, the material 68 could swell or
change shape in response to an increase in temperature. For
example, the material 68 could comprise a temperaturesensitive
wax or a thermal shape memory material, etc.
In FIG. 10, the member 62 comprises a piston which
displaces in response to a pressure differential between the
passage 80 and the passage 44. When it is desired to move
the deflector 58, pressure in the passage 80 is increased or
decreased (e.g., via a line extending to a pressure source
at a remote location, etc.) relative to pressure in the
passage 44.
The deflector 58 is depicted in FIG. 10 as being in the
form of a hinged vane, but it should be clearly understood
that any form of deflector may be used in keeping with this
disclosure. For example, the deflector 58 could be in the
form of an airfoil, etc.
In the FIG. 10 configuration, the position of the
deflector 58 can be dependent on a property (pressure) of
the fluid composition 36.
In FIG. 11, the actuator 60 is operated in response to
application or withdrawal of a magnetic field. For example,
the magnetic field could be applied by conveying a magnetic
device 82 into the passage 80, which could extend through
the tubular string 22 to a remote location.
The actuator 60 in this configuration could include any
of the material 68 discussed above in relation to the FIG. 8
configuration (e.g., materials which can change shape or
move in response to application or withdrawal of a magnetic
field, magnetic shape memory materials, magnetostrictors ,
permanent magnets, ferromagnetic materials, etc.).
The magnetic device 82 could be any type of device
which produces a magnetic field. Examples include permanent
magnets, electromagnets, etc. The device 82 could be
conveyed by wireline, slickline, etc., the device could be
dropped or pumped through the passage 80, etc.
One useful application of the FIG. 11 configuration is
to enable individual or multiple actuators 60 to be
selectively operated. For example, in the well system 10 of
FIG. 1 , it may be desired to increase or decrease resistance
to flow through some or all of the variable flow resistance
systems 25. A magnetic dart could be dropped or pumped
through all of the systems 25 to operate all of the
actuators 60, or a wireline-conveyed electromagnet could be
selectively positioned adjacent some of the systems to
operate those selected actuators.
Referring additionally now to FIG. 12 , an example graph
of pressure or flow rate of the fluid composition 3 6 versus
time is representatively illustrated. Note that the
pressure and/or flow rate can be selectively varied by
operating the actuator 6 0 of the variable flow resistance
system 2 5 , and this variation in pressure and/or flow rate
can be used to transmit a signal to a remote location.
In FIG. 13 , the well system 1 0 is representatively
illustrated while the uncased section 14 of the wellbore 12
is being drilled. The fluid composition 3 6 (known as
drilling mud in this situation) is circulated through a
tubular string 8 4 (a drill string in this situation), exits
a drill bit 8 6 , and returns to the surface via the annulus
2 8 .
The actuator 6 0 can be operated using the controller 7 0
as described above, so that pressure and/or flow rate
variations are produced in the fluid composition 3 6 . These
pressure and/or flow rate variations can have data, commands
or other information modulated thereon. In this manner,
signals can be transmitted to the remote location by the
variable flow resistance system 2 5 .
As depicted in FIG. 13 , a telemetry receiver 8 8 at a
remote location detects the pressure and/or flow rate
variations using one or more sensors 9 0 which measure these
properties upstream and/or downstream of the system 2 5 . In
one example, the system 2 5 could transmit to the remote
location pressure and/or flow rate signals indicative of
measurements taken by measurement while drilling (MWD),
logging while drilling (LWD), pressure while drilling (PWD),
or other sensors 9 2 interconnected in the tubular string 8 4 .
In other examples, the signal-transmitting capabilities
of the system 2 5 could be used in production, injection,
stimulation, completion or other types of operations. In a
production operation, (e.g., the FIG. 1 example), the
systems 2 5 could transmit to a remote location signals
indicative of flow rate, pressure, composition, temperature,
etc. for each individual zone being produced.
It may now be fully appreciated that the above
disclosure provides significant advancements to the art of
variably restricting flow of fluid in a well. Some or all of
the variable flow resistance system 2 5 examples described
above can be operated remotely to reliably regulate flow
between a formation 2 0 and an interior of a tubular string
2 2 . Some or all of the system 2 5 examples described above
can be operated to transmit signals to a remote location,
and/or can receive remotely-transmitted signals to operate
the actuator 6 0 .
In one aspect, the above disclosure describes a
variable flow resistance system 2 5 for use with a
subterranean well. The system 2 5 can include a flow chamber
5 0 through which a fluid composition 3 6 flows, the chamber
5 0 having multiple inlet flow paths 4 6 , 4 8 , and a flow
resistance which varies depending on proportions of the
fluid composition 3 6 which flow into the chamber 5 0 via the
respective inlet flow paths 4 6 , 4 8 . An actuator 6 0 can vary
the proportions of the fluid composition 3 6 which flow into
the chamber 5 0 via the respective inlet flow paths 4 6 , 4 8 .
The actuator 6 0 may deflect the fluid composition 3 6
toward an inlet flow path 4 6 . The actuator 6 0 may displace a
deflector 5 8 relative to a passage 4 4 through which the
fluid composition 3 6 flows.
The actuator 6 0 may comprise a swellable material, a
material which changes shape in response to contact with a
selected fluid type, and/or a material which changes shape
in response to a temperature change.
The actuator 60 can comprise a piezoceramic material,
and/or a material selected from the following group:
piezoelectric, pyroelectric , electrostrictor ,
magnetostrictor , magnetic shape memory, permanent magnet,
ferromagnetic, swellable, polymer hydrogel, and thermal
shape memory. The actuator 60 can comprise an
electromagnetic actuator.
The system 25 may include a controller 70 which
controls operation of the actuator 60. The controller 70 may
respond to a signal transmitted from a remote location. The
signal may comprise an electrical signal, a magnetic signal,
and/or a signal selected from the following group: thermal,
ion concentration, and fluid type.
The fluid composition 36 may flows through the flow
chamber 50 in the well.
The system 25 may also include a fluid switch 66 which,
in response to a change in a property of the fluid
composition 36, varies the proportions of the fluid
composition 36 which flow into the chamber 50 via the
respective inlet flow paths 46, 48. The property may
comprise at least one of the following group: velocity,
viscosity, density, and ratio of desired fluid to undesired
fluid.
Deflection of the fluid composition 36 by the actuator
60 may transmit a signal to a remote location. The signal
may comprise pressure and/or flow rate variations.
Also provided by the above disclosure is a method of
variably controlling flow resistance in a well. The method
can include changing an orientation of a deflector 58
relative to a passage 44 through which a fluid composition
36 flows, thereby influencing the fluid composition 36 to
flow toward one of multiple inlet flow paths 46, 48 of a
flow chamber 50, the chamber 50 having a flow resistance
which varies depending on proportions of the fluid
composition 36 which flow into the chamber 50 via the
respective inlet flow paths 46, 48.
Changing the orientation of the deflector 58 can
include transmitting a signal to a remote location.
Transmitting the signal can include a controller 70
selectively operating an actuator 60 which displaces the
deflector 58 relative to the passage 44.
It is to be understood that the various examples
described above may be utilized in various orientations,
such as inclined, inverted, horizontal, vertical, etc., and
in various configurations, without departing from the
principles of the present disclosure. The embodiments
illustrated in the drawings are depicted and described
merely as examples of useful applications of the principles
of the disclosure, which are not limited to any specific
details of these embodiments.
Of course, a person skilled in the art would, upon a
careful consideration of the above description of
representative embodiments, readily appreciate that many
modifications, additions, substitutions, deletions, and
other changes may be made to these specific embodiments, and
such changes are within the scope of the principles of the
present disclosure. Accordingly, the foregoing detailed
description is to be clearly understood as being given by
way of illustration and example only, the spirit and scope
of the present invention being limited solely by the
appended claims and their equivalents.

WHAT IS CLAIMED
1 . A variable flow resistance system for use with a
subterranean well, the system comprising:
a flow chamber through which a fluid composition flows,
the chamber having multiple inlet flow paths, and a flow
resistance which varies depending on proportions of the
fluid composition which flow into the chamber via the
respective inlet flow paths; and
an actuator which varies the proportions of the fluid
composition which flow into the chamber via the respective
inlet flow paths.
2 . The system of claim 1 , wherein the actuator
displaces a deflector relative to a passage through which
the fluid composition flows.
3 . The system of claim 1 , wherein the actuator
comprises a swellable material.
4 . The system of claim 1 , wherein the actuator
comprises a material which changes shape in response to
contact with a selected fluid type.
5 . The system of claim 1 , wherein the actuator
comprises a material which changes shape in response
temperature change.
6 . The system of claim 1 , wherein the actuator
comprises a piezoceramic material.
7 . The system of claim 1 , wherein the actuator
comprises a material selected from the following group:
piezoelectric, pyroelectric , electrostrictor ,
magnetostrictor , magnetic shape memory, permanent magnet,
ferromagnetic, swellable, polymer hydrogel, and thermal
shape memory.
8 . The system of claim 1 , wherein the actuator
comprises an electromagnetic actuator.
9 . The system of claim 1 , further comprising a
controller which controls operation of the actuator, and
wherein the controller responds to a signal transmitted from
a remote location.
10. The system of claim 9 , wherein the signal
comprises an electrical signal.
11. The system of claim 9 , wherein the signal
comprises a magnetic signal.
12. The system of claim 9 , wherein the signal
comprises a type selected from the following group: thermal,
ion concentration, and fluid type.
13. The system of claim 1 , wherein the fluid
composition flows through the flow chamber in the well.
14. The system of claim 1 , further comprising a fluid
switch which, in response to a change in a property of the
fluid composition, varies the proportions of the fluid
composition which flow into the chamber via the respective
inlet flow paths.
15. The system of claim 14, wherein the property
comprises at least one of the following group: velocity,
viscosity, density, and ratio of desired fluid to undesired
fluid.
16. The system of claim 1 , wherein deflection of the
fluid composition by the actuator transmits a signal to a
remote location.
17. The system of claim 16, wherein the signal
comprises pressure variations.
18. The system of claim 16, wherein the signal
comprises flow rate variations.
19. A method of variably controlling flow resistance
in a well, the method comprising:
changing an orientation of a deflector relative to a
passage through which a fluid composition flows, thereby
influencing the fluid composition to flow toward one of
multiple inlet flow paths of a flow chamber, the chamber
having a flow resistance which varies depending on
proportions of the fluid composition which flow into the
chamber via the respective inlet flow paths.
20. The method of claim 19, wherein changing the
orientation of the deflector further comprises transmitting
a signal to a remote location.
21. The method of claim 20, wherein transmitting the
signal further comprises a controller selectively operating
an actuator which displaces the deflector relative to the
passage .
22. The method of claim 20, wherein the signal
comprises pressure variations.
23. The method of claim 20, wherein the signal
comprises flow rate variations.
24. The method of claim 19, wherein changing the
orientation of the deflector further comprises operating an
actuator which comprises a swellable material.
25. The method of claim 19, wherein changing the
orientation of the deflector further comprises operating an
actuator which comprises a material which changes shape in
response to contact with a selected fluid type.
26. The method of claim 19, wherein changing the
orientation of the deflector further comprises operating an
actuator which comprises a material which changes shape in
response to a temperature change.
27. The method of claim 19, wherein changing the
orientation of the deflector further comprises operating an
actuator which comprises a piezoceramic material.
28. The method of claim 19, wherein changing the
orientation of the deflector further comprises operating an
actuator which comprises a material selected from the
following group: piezoelectric, pyroelectric ,
electrostrictor , magnetostrictor , magnetic shape memory,
permanent magnet, ferromagnetic, swellable, polymer
hydrogel, and thermal shape memory.
29. The method of claim 19, wherein changing the
orientation of the deflector further comprises operating an
electromagnetic actuator.
30. The method of claim 19, wherein changing the
orientation of the deflector further comprises operating an
actuator in response to a signal transmitted from a remote
location.
31. The method of claim 30, wherein the signal
comprises an electrical signal.
32. The method of claim 30, wherein the signal
comprises a magnetic signal.
33. The method of claim 30, wherein the signal
comprises a type selected from the following group: thermal,
ion concentration, and fluid type.
34. The method of claim 19, wherein the fluid
composition flows through the flow chamber in the well.
35. The method of claim 19, wherein a fluid switch, in
response to a change in a property of the fluid composition,
varies the proportions of the fluid composition which flow
into the chamber via the respective inlet flow paths.
36. The method of claim 35, wherein the property
comprises at least one of the following group: velocity,
viscosity, density, and ratio of desired fluid to undesired
fluid.
37. A variable flow resistance system for use with a
subterranean well, the system comprising:
a flow chamber through which a fluid composition flows,
the chamber having at least first and second inlet flow
paths, and a flow resistance which varies depending on
proportions of the fluid composition which flow into the
chamber via the respective first and second inlet flow
paths; and
an actuator which deflects the fluid composition toward
the first inlet flow path.
38. The system of claim 37, wherein the actuator
displaces a deflector relative to a passage through which
the fluid composition flows.
39. The system of claim 37, wherein the actuator
comprises a piezoceramic material.
40. The system of claim 37, wherein the actuator
comprises a material selected from the following group:
piezoelectric, pyroelectric , electrostrictor ,
magnetostrictor , magnetic shape memory, permanent magnet,
ferromagnetic, swellable, polymer hydrogel, and thermal
shape memory.
41. The system of claim 37, wherein the actuator
comprises an electromagnetic actuator.
42. The system of claim 37, further comprising a
controller which controls operation of the actuator, and
wherein the controller responds to a signal transmitted
a remote location.
43. The system of claim 42, wherein the signal
comprises an electrical signal.
44. The system of claim 42, wherein the signal
comprises a magnetic signal.
45. The system of claim 42, wherein the signal
comprises a type selected from the following group: thermal,
ion concentration, and fluid type.
46. The system of claim 37, wherein the fluid
composition flows through the flow chamber in the well.
47. The system of claim 37, further comprising a fluid
switch which, in response to a change in a property of the
fluid composition, varies the proportions of the fluid
composition which flow into the chamber via the respective
first and second inlet flow paths.
48. The system of claim 47, wherein the property
comprises at least one of the following group: velocity,
viscosity, density, and ratio of desired fluid to undesired
fluid.
49. The system of claim 37, wherein deflection of the
fluid composition by the actuator transmits a signal to a
remote location.
50. The system of claim 49, wherein the signal
comprises pressure variations.
51. The system of claim 49 wherein the signal
comprises flow rate variations.