Note: Descriptions are shown in the official language in which they were submitted.
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CONTROLLABLE PRODUCTION WELL PACKER
BACI{GROUND OF THE INVENTION
Field of the Invention
The present invention relates to a controllable production well packer. In one
aspect, it relates to a petroleum production well packer comprising an
electrically
powered device, in which the device may comprise an electrically controllable
valve, a
communications and control module, a sensor, a modem, a tracer injection
module, or
any combination thereof.
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Description of the Related Art
Petroleum wells (e.g., oil and/or gas wells) typically pass through formations
containing multiple zones that may produce differing fluids, as well as
impermeable
zones. The fluid-bearing zones may produce saline or clear water, oil, gas, or
a mixture
of these components.
It is desirable and customary to maintain hydraulic isolation between zones so
that the fluids produced from each zone may be received separately at the
surface. Even
if a particular zone is not producing petroleum products, it is usually
necessary to ensure
that fluids from that zone do not travel to otlier zones using the wellbore as
a transport
path, and to avoid contamination of the fluids in each zone.
The necessary isolation between zones is often provided by packers. A typical
hydraulically set production packer of the prior art is schematically shown in
FIG. 1.
Packers are.mechanical devices that close the annulus between the production
tubing and
the casixig, and seal to both. Packers are typically installed at the time of
well.
coinpletion by attaching them to a tubing string as it is lowered into the
well. - Thus,
during placement, the packer must pass freely within the casing. Once it is in
place, a.
hydraulic actuator (energized and controlled from the surface) operates the
sealing
mechanism of the packer, which clamps the packer to the casing and effects a
fluid-tight
seal in the annular space between the tubing and the casing.
Packers may provide complete isolation between the annular spaces above and
below them, or may be equipped with one or more preset mechanically-actuated
valves
to control flow past them. When control valves are included, however, their
settings can
only be altered by mechanically inserting a slick-line tool, which is
inconvenient, slow,
and relatively costly. Additionally, when there are multiple zones and
multiple packers it
is often impossible or impractical to reach the lowermost packers with a slick-
line tool.
This lack of a fast and inexpensive method for controlling valves in a packer
is a
constraint on well design and production operations.
Conventional packers are known such as described in U.S. Patents 6,148,915,
6,123,148, 3,566,963 and 3,602,305.
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All references cited herein are incorporated by reference to the maximum
extent
allowable by law. To the extent a reference may not be fully incorporated
herein, it is
incorporated by reference for background purposes, and indicative of the
knowledge of
one of ordinary skill in the art.
BRIEF SIIMMARY OF THE INVENTION
The problems and needs outlined above are largely solved and met by the
present
invention. In accordance with one aspect of the present invention, a packer
adapted for
use in a petroleum well, wherein the packer comprises an electrically powered
device, is
provided. The electrically powered device may comprise an electrically
controllable
valve adapted to control fluid communication from one side of the packer to
another side
of the packer when the packer is operably installed. The electrically powered
device
inay further comprise a communications and control module being electrically
connected
to the electrically controllable valve, wherein the module comprises a modem
adapted to
receive control commands encoded within communication signals. The module can
be
adapted to decode the control commands received by the modem and control the
movement of the valve using the control commands when the packer is operably
installed. Alternatively, the electrically powered device may comprise a
sensor -adapted
to detect at least one physical characteristic of a surrounding environment
and generate
data corresponding to the physical characteristic, as well as a inodem adapted
to receive
the data from the sensor and electrically transmit the data in the form of an
electrical
communication signal. Hence, the electrically powered device can comprise an
electrically controllable valve, a sensor, a modem, a communications and
control
module, a tracer injection module, or any combination thereof.
In accordance with another aspect of the present invention, a petroleum
production well incorporating the packer described above is provided. The
petroleum
well comprises a piping structure, a source of time-varying current, an
electrical return,
aninduction choke, and the packer. The piping structure of the well comprises
an
electrically conductive portion extending along at least part of the piping
structure. The
piping structure can comprise a production tubing string of the well.' The
source of time-
varying current comprises two source terminals. A first of the source
terminals is
electrically connected to the electrically conductive portion of the piping
structure. The
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electrical return electrically connects between the electrically conductive
portion of the
piping structure and a second of the source terminals of the time-varying
current source.
The electrical return can comprise a well casing of the well, part of the
packer, another
packer, and/or a conductive fluid within the well. The induction choke is
located about
part of the electrically conductive portion of the piping structure at a
location along the
piping structure between the electrical connection location for the first
source terminal
and the electrical connection location for the electrical return, such that a
voltage
potential is formed between the electrically conductive portion of the piping
structure on
a source-side of the induction choke, and the electrically conductive portion
of the .piping
structure on an electrical-return-side of the induction choke as well as the
electrical
return when time-varying current flows through the electrically conductive
portion of the
piping structure. The induction choke can comprise a ferromagnetic material.
Also, the
induction choke need not be powered when its size, geometry, and magnetic
properties
can provide sufficient magnetic inductance for developing the voltage
potential desired.
The electrically powered device of the packer is electrically connected across
the voltage
20_ potential such that part of the time-varying current is routed through the
device due to the
induction choke when the time-varying current flows through the electrically
conductive
portion of the piping structure.
In accordance with yet another aspect of the present invention, a method of
producing petroleum products from a petroleum well comprising an electrically
powered
packer is provided.
A conventional petroleum well includes a cased wellbore having a tubing string
positioned within and longitudinally extending within the casing. In a
preferred
embodiment, a controllable packer is coupled to the tubing to provide a seal
of the
annular space between the tubing and casing. A valve in the packer (and/or
other
devices, such as sensors) is powered and controlled from the surface.
Communication
signals and power are sent from the surface using the tubing and casing as
conductors.
At least one induction choke is coupled about the tubing downhole to
magnetically
inhibit alternating current flow through the tubing at a choke. An insulating
tubing joint,
another induction cholce, or another insulating means between the tubing and
casing can
be located at the surface above a location where current and communication
signals are
imparted to the tubing. Hence, most of the altemating current is contained
between the
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downhole choke and the insulating tubing joint, or between the chokes when two
chokes
are used.
As is known in the prior art, there are alternative ways to provide electrical
power
from the surface to downhole modules, and to establish bidirectional
communications for
data and commands to be passed between the surface and downhole modules using
surface and downhole modems. A preferred embodiment utilizes the production
tubing
and the well casing as the electrical conduction path between the surface and
downhole
equipment. The cost reduction and simplification of installation procedures
which
accrue from obviating the need for electrical cables to provide power,
sensing, and
control functions downhole allow wider deployment of active equipment downhole
during production.
In the context of downhole packers, the ability to power and communicate with
the packer has many advantages. Such a controllable packer in accordance with
the
present invention may iuicorporate sensors, with data from the sensors being
Teceived in
real time at the surface. Similarly,=the availability of power downhole, and
the ability to
:.20 pass commands from the surface to the controllable packer,
allow~electricall,y motorized
mechanical components, such as flow control valves, to be included in packer
design,
thus increasing their flexibility in use. Notably, the control of such
components in the
controllable packer hereof is near real time, allowing packer flow control
valves to be
opened, closed, adjusted, or throttied constantly to contribute to the
management of
production.
In a preferred embodiment, a surface computer having a master modem can
impart a communication signal to the tubing, and the conununica.tion signal is
received at
a slave modem downhole, which is electrically connected to or within the
controllable
packer. The communication signal can be received by the slave modem either
directly or
indirectly via one or more relay modems. Further, electric power can be input
into the
tubing string and received downhole to power the operation of sensors or other
devices
in the controllable packer. Preferably, the casing is used as a conductor for
the electrical
return.
In a preferred embodiment, a controllable valve in the packer regulates the
fluid
coinniunication in the annulus between the casing and tubing. The electrical
return path
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can be provided along part of the controllable packer, and preferably by the
expansion of
the expansion slips into contact with the casing. Alternatively, the
electrical return path
may be via a conductive centralizer around the tubing which is insulated in
its contact
with the tubing, but is in electrical contact with the casing and electrically
connected to
the device in the packer.
In enhanced forms, the controllable packer includes one or more sensors
downhole which are preferably in contact with the downhole modem and
communicate
with the surface computer via the tubing and/or well casing. Such sensors as
temperature, pressure, acoustic, valve position, flow rates, and differential
pressure
gauges can be advantageously used in many situations. The sensors supply
measurements to the modem for transmission to the surface or directly to a
programmable interface controller operating a downhole device, such as
controllable
valve for controlling the fluid flow through the packer.
In one embodiment, ferromagnetic induction chokes are coupled about the tubing
to act as a series impedance.to current flow on the tubing. In a preferred
form, an upper
ferromagnetic chokc is -placed around the tubing below the casinghanger, and
the current
and communication signals are imparted to the tubing below the upper
ferromagnetic
choke. A lower ferronlagnetic choke is placed downhole around the tubing with
the
controllable packer electrically coupled to the tubulg above the lower
ferromagnetic
choke, although the controllable packer may be mechanically coupled to the
tubing
below the lower ferromagnetic choke instead.
Preferably, a surface computer is coupled via a surface master modem and the
tubing to the downhole slave modem of the controllable packer. The surface
computer
can receive measurements from a variety of sources (e.g., downhole sensors),
measurements of the oil output from the well, and measurements of the
compressed gas
input to the well in the case of a gas lift well. Using such measurements, the
computer
can compute desired positions of the controllable valve in the packer, and
more
particularly, the optimum amount of fluid communication to permit into the
annulus
inside the casing.
Construction of such a petroleum well is designed to be as similar to
conventional
construction methodology as possible. That is, after casing the well, a packer
is typically
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set to isolate each zone. In a production well, there may
be several oil producing zones, water producing zones,
impermeable zones, and thief zones. It is desirable to
prevent or permit communication between the zones. For
example when implementing the present invention, the tubing
string is fed through the casing into communication with the
production zone, with controllable packers defining the
production zone. As the tubing string is made up at the
surface, a lower ferromagnetic choke is placed around one of
the conventional tubing strings for positioning above the
lowermost controllable packer. In the sections of the
tubing strings where it is desired, another packer is
coupled to the tubing string to isolate zones. Controllable
gas lift valves or sensor pods also may be coupled to the
tubing as desired by insertion in a side pocket mandrel
(tubing conveyed) and corresponding induction chokes as
needed. The tubing string is made up to the surface where
an upper ferromagnetic induction choke is again placed
around the tubing string below the casing hanger.
Communication and power leads are then connected to the
tubing string below the upper choke. In an enhanced form,
an electrically insulating joint is used instead of the
upper induction choke.
A sensor and communication pod can be incorporated
into the controllable packer of the present invention
without the necessity of including a controllable valve or
other control device. That is, an electronics module having
pressure, temperature or acoustic sensors, power supply, and
a modem can be incorporated into the packer for
communication to the surface computer using the tubing and
casing as conductors.
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In one broad aspect, there is provided a petroleum
well for producing petroleum products, comprising: a piping
structure comprising an electrically conductive portion
extending along at least part of said piping structure; a
source of time-varying current electrically connected to
said electrically conductive portion of said piping
structure; an electrical return; and a packer including an
electrically powered device; wherein an induction choke is
installed about part of the electrically conductive portion
of the piping structure; and that said electrically powered
device is electrically connected to the piping structure at
a source side and at an electrical return side of the
induction choke such that part of said time-varying current
is routed through said device when said time-varying current
is applied through said electrically conductive portion of
said piping structure.
In another broad aspect, there is provided a
method of operating a petroleum well comprising: providing
an electrically powered packer in a petroleum well;
providing a piping structure in said well, said piping
structure comprising an electrically conductive portion
extending along at least part of said piping structure;
operably installing said electrically powered packer in said
well, said electrically powered packer comprising an
electrically powered device, such that said device is
electrically connected to said electrically conductive
portion of said piping structure when said well is operable
for petroleum production; wherein the method further
comprises: operably installing an induction choke about part
of said electrically conductive portion of said piping
structure; supplying time-varying current to said piping
structure; routing part of said time-varying current through
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said electrically powered device using said induction choke;
and producing petroleum products with said well.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the invention will
become apparent upon reading the following detailed
description and upon referencing the accompanying drawings,
in which:
FIG. 1 is a schematic showing a typical packer of
the prior art;
FIG. 2 is a schematic showing a petroleum
production well in accordance with a preferred embodiment of
the present invention;
FIG. 3 is a simplified electrical schematic of the
embodiment shown in FIG. 2; and
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FIG. 4 is an enlarged schematic showing a controllable packer, from FIG. 2,
comprising an electrically controllable valve.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, wherein Iike reference numbers are used herein
to
designate like elements tluoughout the various views, a preferred embodiment
of the
present invention is illustrated and further described, and other possible
embodiments of
the present invention are described. The figures are not necessarily drawn to
scale, and
in some instances the drawings have been exaggerated and/or simplified in
places for
illustrative purposes only. One of ordinary skill in the art will appreciate
the many
possible applications and variations of the present invention based on the
following
examples of possible embodiments of the present invention, as well as based on
those
embodiments illustrated and discussed in the Related Applications, which are
incorporated by reference herein to the maximum extent allowed by law.
As used in the present application, a"piping structure" can be one single
pipe, a
tubing string, a well casing, a pumpiri g rod, a series of interconnected
pipes, rods, rails,
trusses, lattices, supports, a branch or lateral extension of a well, a
network, of
interconnected pipes; or other siinilar structures known to one of ordinary
skill in the art.
The preferred embodiment makes use of the invention in the context of a
petroleum wel1.
where the piping structure comprises tubular, metallic, electrically-
conductive pipe or
tubing strings, but tne invention is not so iimited. ror the present
invention, at least a
portion of the piping structure needs to be electrically conductive, such
electrically
coriductive portion may be the entire piping structure (e.g., steel pipes,
copper pipes) or a
longitudinal extending electrically conductive portion combined with a
longitudinally
extending non-conductive portion. In other words, an electrically conductive
piping
structure is one that provides an electrical conducting path from a first
portion where a
power source is electrically connected to a second portion where a device
and/or
electrical return is electrically connected. The piping structure will
typically be
conventional round metal tubing, but the cross-section geometry of the piping
structure,
or any portion thereof, can vary in shape (e.g., round, rectangular, square,
oval) and size
(e.g., length, diameter, wall thickness) along any portion of the piping
structure. Hence,
a piping structure must have an electrically conductive portion extending from
a first
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portion of the piping structure to a second portion of the piping structure,
wherein the
first portion is distally spaced from the second portion along the piping
structure.
Note that the terms "first portion" and "second portion" as used herein are
each
defined generally to call out a portion, section, or region of a piping
structure that niay or
may not extend along the piping structure, that can be located at any chosen
place along
the piping structure, and that may or may not encompass the most proximate
ends of the
piping structure.
Similarly, in accordance with conventional terminology of oilfield practice,
the
descriptors "upper", "lower", "uphole" and "downhole" are relative and refer
to distance
along hole depth from the surface, which in deviated or horizontal wells may
or may not
accord with vertical elevation measured with respect to a survey datum.
Also note that the term "modem" is used herein to generically refer to any
communications device for transmitting and/or receiving electrical
communication
signals via an electrical conductor (e.g., metal). Hence, the term "modem" as
used
herein is not liniited to the acronym for a modulator (device that converts a
voice or data
signal into a form that can be transmitted)/demodulator (a device that
recovers an
original signal after it has modulated a high frequency carrier). Also, the
term "niodein"
as used herein is not limited to conventional computer modems that convert
digital
signals to analog signals and vice versa (e.g., to send digital data signals
over the analog
Public Switched Telephone Network). For example, if a sensor outputs
measurements in
an analog format, then such measurements may only need to be modulated (e.g.,
spread
spectrum modulation) and transmitted--hence no analog/digital conversion
needed. As
another example, a relay/slave modem or communication device may only need to
identify, filter, amplify,- and/or retransmit a signal received.
As used in the present application, "wireless" means the absence of a
conventional, insulated wire conductor e.g. extending from a downhole device
to the
surface. -Using the tubing and/or casing as a conductor is considered
"wireless." The
term "valve" as used herein generally refers to any device that functions to
regulate the
flow of a fluid. Examples of valves include, but are not limited to, bellows-
type gas-lift
- valves and controllable gas-lift valves, each of which may be used to
regulate the flow of
lift gas itnto a tubing string of a well. The internal workings of valves can
vary greatly,
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and in the present application, it is not intended to limit the valves
described to any
particular configuration, so long as the valve functions to regulate flow.
Some of the
various types of flow regulating mechanisms include, but are not limited to,
ball valve
configurations, needle valve configurations, gate valve configurations, and
cage valve
configurations. The methods of installation for valves discussed in the
present
application can vary widely.
The term "electrically controllable valve" as used herein generally refers to
a
"valve" (as just described) that can be opened, closed, adjusted, altered, or
throttled
continuously in response to an electrical control signal (e.g., signal from a
surface
computer or from a downhole electronic controller module). The mechanism that
actually moves the valve position can comprise, but is not limited to: an
electric motor;
an electric servo; an electric solenoid; an electric switch; a hydraulic
actuator controlled
by at least one electrical servo, electrical motor, electrical switch,
electric solenoid, or
combinations thereof; a pneumatic actuator controlled by at least one
electrical servo,
electrical motor, electrical switch, electric solenoid, or combinations
thereof; or a spring
biased device in combination with at least one electrical servo, electrical
motor, electrical
switch, electric solenoid, or combinations thereof.. An "electrically
controllable valve"
may or may not include a position feedback sensor for providing a feedback
signal
corresponding to the actual position of the valve.
The term "sensor" as LLsed herein refers to any device that detects,
determines,
monitors, records, or otherwise senses the absolute value of or a change in a
physical
quantity. A sensor as described herein can be used to measure physical
quantities
including, but not limited to: temperature, pressure (both absolute and
differential), flow
rate, seismic data, acoustic data, pH level, salinity levels, valve positions,
or almost any
other physical data.
FIG. I is a schematic showing a conventional hydraulically set production
packer 20 of the prior art set within a well casing 22 of a well. The packer
20 of FIG. 1
is threaded to a production tubing string 24. The conventional packer 20 has a
tail piece
26 that may terminate with an open or closed end for the lowest packer in the
completed
well, or the tail piece 26 may be threaded onto tubing (not shown) that passes
to lower
regions of the well. The conventional packer 20 has a section of slips 28 and
a seal
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section 30. Both the slips 28 and the seal section 30 can pass freely inside
the well
casing 22 during placement, and are operated by a hydraulic actuator 32. When
the
packer 20 is at its final location in the casing 22, the hydraulic actuator 32
is used to
exert mechanical forces on the slips 28 and the seals 30 causing them to
expand against
the casing. The slips 281ock the packer 20 in place by gripping the internal
surface of
the casing 22 so that the packer cannot be displaced by differential pressure
between the
spaces above and below the packer. The seal section 30 creates a liquid-tight
seal
between the spaces above and below the packer 20. The hydraulic actuator 32 is
operated using high-pressure oil supplied from the surface (not shown) by a
control tube
34. However, the conventional packer 20 does not comprise an electrically
powered
device.
FIG. 2 is a schematic showing a petroleurri production wel138 in accordance
with
a preferred embodiment of the present invention. The petroleum production well
38
shown in FIG. 2 is similar to a conventional well in construction, but with
the
incorporation of the present invention. In this example, a packer 40
comprising an
electrically powered device 42 is placed in the well 38 in the same manner as
a
conventional packer 20 would be-to separate zones in a formation. In the.
preferred
embodiment, the electrically powered device 42 of the packer 40 comprises an
electrically controllable valve 44 that acts as a bypass valve, as shown in
more detail in
FIG. 4 and described further below.
In a preferred embodiment, the piping structure comprises part of a production
tubing string 24, and the electtrical return comprises part of a well casing
22. An
insulating tubing joint.146 and a ferromagnetic induction choke 48 are used in
tlus
preferred enibodiment. The insulating joint 146 is incorporated close to the
wellhead to
electrically insulate the lower sections of tubing 24 from casing 22. Thus,
the insulating
joint 146 prevents an electrical short-circuit between the lower sections of
tubing 24 and
casing 22 at the tubing hanger 46. The hanger 46 provides mechanical coupling
and
support of the tubing 24 by transferring the weight load of the tubing 24 to
the casing 22.
The induction choke 48 is attached about the tubing string 24 at a second
portion 52
downhole above the packer 40. A computer system 56 comprising a master modem
58
and a source of time-varying current 60 is electrically connected to the
tubing string 24
below the insulating tubing joint 146 by a first source terminal 61. The first
source
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terminal 61 is insulated from the hanger 46 where it passes through it. A
second source
terminal 62 is electrically connected to the well casuzg 22, either directly
(as in FIG. 2)
or via the hanger 46 (arrangement not shown). In alternative to or in addition
to the
insulating tubing joint 146, another induction choke (not shown) can be placed
about the
tubing 24 above the electrical connection location for the first source
tenninal 61 to the
tubing.
The time-varying current source 60 provides the current, which carries power
and
communication signals downhole. The time-varying current is preferably
alternating
current (AC), but it can also be a varying direct current (DC). The
communication
signals can be generated by the master modem 58 and embedded within the
current
produced by the source 60. Preferably, the communication signal is a spread
spectrum
signal, but other forms of modulation could be used in alternative.
The electrically powered device 42 in the packer 40 coniprises two device
tenninals 71, 72, and there can be other device terminals as needed for other
embodiments or applications. A first device termina171 is electrically
connected to the
tubing 24 on a source-side 81 of the induction choke 48, which in this case is
above the
induction choke. Similarly, a second device terminal 72 is electrically
connected to the
tubing 24 on an electrical-return-side, 82 of the induction choke 48, which in
this case is
below the induction choke. Iii this preferred embodiment, the slips 28 of the
packer 40
provide the electrical connection between the tubing 24 and the well casing
22.
However, as will be clear to one of ordinary skill in the art, the electrical
connection
between the tubing 24 and the well casing 22 can be accomplished in nunierous
ways,
some of which can be seen in the Related Applications, including (but not
limited to):
another packer (conventional or controllable); conductive fluid in the annulus
between
the tubing and the well casing; a conductive centralizer; or any combination
thereof.
Hence, an electrical circuit is formed using the tubing 24 and the well casing
22 as
conductors to the downhole device 42 within the packer 40.
FIG. 3 illustrates a simplified electrical schematic of the electrical circuit
formed
in the well 38 of FIG. 2. The insiilating tubing joint 146 and the induction
choke 48
effectively create an isolated. section of the tubing string 24 to contain
most of the time-
varying current between them. Accordingly, a voltage potential develops
between the
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isolated section of tubing 24 and the well casing 22 when AC flows through the
tubing
string. Likewise, the voltage potential also forms between tubing 24 on the
source-side
81 of the induction choke 48 and the tubing 24 on the electrical-return-side
82 of the
induction choke 48 when AC flows through the tubing string. In the preferred
embodiment, the electrically powered device 42 in the packer 40 is
electrically connected
across the voltage potential between the source-side 81 and the electrical-
return-side 82
of the tubing 24. However in alternative, the device 42 can be electrically
connected
across the voltage potential between the tubing 24 and the casing 22, or the
voltage
potential between the tubing 24 and part of the packer 40 (e.g., slips 28), if
that part of
the packer is electrically contacting the well casing 22. Thus, part of the
current that
travels through the tubing 24 atid casing 22 is routed through the device 42
due to the
induction choke 48.
As is made clear by consideration of the electrical equivalent cir.cuit
.diagram of
FIG. 3, centralizers which are installed on the tubing between isolation
device 47 and
choke 48 must not provide an electrically conductive path between tubing 24
and casing
22. Suitable centralizers may be corriposed of solid molded or machined
plastic, or may
be of the bow-spring type provided these are furnished with appropriate
insulating
elements. Many suitable and alternative design implementations of such
centralizers will
be clear to those of average skill in the art.
Other alternative ways to develop an electrical circuit using a piping
structure and.
at least one induction choke are described in the Related Applications, many
of which
can be applied in conjunction with the present invention to provide power
and/or
communications to the electrically powered device 42 of the packer 40 and to
form other
embodiments of the present invention.
Turning to FIG. 4, which shows more details of the packer 40 of FIG. 2, it is
seen
that. the controllable packer 40 is similar to the conventional packer 20
(shown in FIG.
1), but with the addition of an electrically powered device 42 comprising an
electrically
controllable valve 44 and a conimunications and control module 84. The
communications and control module 84 is powered from and communicates with the
computer systein 56 at the surface 54 via the tubing 24 and/or the casing 22.
The
communications and control module 84 may comprise a modem 86, a power
transformer
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(not shown), a microprocessor (not shown), andlor other various electronic
components
(not shown) as needed for an embodiment. The communications and control module
84
receives electrical signals from the computer systen156 at the surface 54 and
decodes
commands for controlling the electrically controlled valve 44, which acts as a
bypass
valve. Using the decoded commands, the conununications and control module 84
controls a low current electric motor that actuates the movement of the bypass
valve 44.
Thus, the valve 44 can be opened, closed, adjusted, altered, or throttled
continuously by
the computer system 56 from the surface 54 via the tubing 24 and well casing
22.
The bypass valve 44 of FIG. 4 controls flow through a bypass tube 88, which
connects inlet and outlet ports 90, 92 at the bottom and top of the packer 40.
The
ports 90, 92 communicate freely with the amiular spaces 94, 96 (between the
casing 22
and the tubing 24), above and below the packer 40. The bypass control valve 44
therefore controls fluid exchange between these spaces 94, 96, and this
exchange may be
altered in real time using commands sent from the computer system 56 and
received by
the controllable packer 40_
The mechanical arrangement of the packer 40 depicted in FIG. 4 is
illustrative,
and alternative embodunents having other-mechanical features providing the
same
functional needs of a packer- (i.e., fluidly isolating and sealing one casing
section from
another casing section in a well, and in the case of a controllable packer,
regulating and
controlling fluid flow between these isolated casing sections) are possible
and
encompassed within the present invention. For instance, the inlet and outlet
ports 90, 92
may be exchanged to pass fluids from the annular space 94 above the packer 40
to the
space 96 below the packer. Also, the conlniunications and control module 84
and the
bypass control valve 44 may be located in upper portion of the packer 40,
above the
slips 28. The controllable-packer 40 may also comprise sensors (not shown)
electrically
connected to or within the communication and control module 84, to measure
pressures
or temperatures in the annuli 94, 96 or within the production tubing 24.
Hence, the
measurements can be transmitted to the computer system 56 at - the surface 54
using the
communications and control module 84, providing real time data on downhole
conditions. Also the setting and unsetting mechanism of the packer slips may
be
actuated by one or more motors driven and controlled by power and commands
received
by module 84.
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63293-3901
In other possible embodiments of the present invention, the electrically
powered
device 42 of the packer 40 may comprise: a modem 86; a sensor (not shown); a
microprocessor (not shown); a packer valve 44; a tracer injection module (not
shown); an
electrically controllable gas-lift valve (e.g., for controlling the flow of
gas from the
annulus to inside the tubing) (not shown); a tubing valve (e.g., for varying
the flow of a
tubing section, such as an application having multiple branches or laterals)
(not shown);
a communications and control module 84; a logic circuit (not shown); a relay
modem
(not shown); other electronic components as needed (not shown); or any
combination
thereof.
Also in other possible embodiments of the present invention, there may be
multiple controllable packers and/or multiple induction chokes. In an
application where
there are:multiple controllable packers or additional conventional packers
combined with
the present invention, it may be necessary to electrically insulate some or
all of the
packers so that a packer does not act as a short between the piping structure
(e.g.,
tubing 24) and the electrical return (e.g., casing 22) where such a short is
not desired.
Such electrical insulation of a packer may be achieved in various ways
apparent to;one of
ordinary skill in the art, including (but not limited to): an insulating
sleeve. alSout the:
tubing at the packer location; a rubber or urethane portion at the radial
extent of the
packer slips; an insulating coating on the tubing at the packer location;
forming the slips
from non-ele6trically-conductive materials; other known insulating means; or
any
combination thereof. The present invention also can be applied to other types
of wells
(other than petroleum wells), such as a water well.
It will be appreciated by those skilled in the art having the benefit of this
disclosure that this invention provides a packer comprising an electrically
powered
device, as well as a petroleum production well incorporating such a packer. It
should be
understood that the drawings and detailed description herein are to be
regarded in an
illustrative rather than a restrictive manner, and are not intended to limit
the invention to
the particular fonns and examples disclosed. On the contrary, the invention
includes any
further modifications, changes, rearrangements, substitutions, alternatives,
design
choices, and embodiments apparent to those of ordinary skill in the art,
without departing
from the spirit and scope of this invention, as defined by the following
claims. Thus, it is
intended that the following claims be interpreted to embrace all such further
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63293-3901
modifications, changes, rearrangements, substitutions, altematives, design
choices, and
embodiments.
18
