U.S. patent application number 12/400024 was filed with the patent office on 2009-07-02 for harvesting vibration for downhole power generation.
This patent application is currently assigned to SCHLUMBERGER TECHNOLOGY CORPORATION. Invention is credited to Stephane Hiron, Thomas D. MacDougall, Dinesh R. Patel, Anthony F. Veneruso, Joe Walter, Rodney J. Wetzel.
Application Number | 20090166045 12/400024 |
Document ID | / |
Family ID | 35429956 |
Filed Date | 2009-07-02 |
United States Patent
Application |
20090166045 |
Kind Code |
A1 |
Wetzel; Rodney J. ; et
al. |
July 2, 2009 |
HARVESTING VIBRATION FOR DOWNHOLE POWER GENERATION
Abstract
A system that is usable with a subterranean well includes a
winding, a member and a circuit. The winding is located downhole in
the well, and the member moves relative to the winding in response
to vibration occurring in the well to cause a signal to be
generated on the winding. The circuit is coupled to the winding to
respond to the signal to provide power to operate a component
located downhole in the well.
Inventors: |
Wetzel; Rodney J.; (Katy,
TX) ; Hiron; Stephane; (Igny, FR) ; Veneruso;
Anthony F.; (Sugar Land, TX) ; Patel; Dinesh R.;
(Sugar Land, TX) ; MacDougall; Thomas D.; (Sugar
Land, TX) ; Walter; Joe; (Sugar Land, TX) |
Correspondence
Address: |
SCHLUMBERGER RESERVOIR COMPLETIONS
14910 AIRLINE ROAD
ROSHARON
TX
77583
US
|
Assignee: |
SCHLUMBERGER TECHNOLOGY
CORPORATION
Sugar Land
TX
|
Family ID: |
35429956 |
Appl. No.: |
12/400024 |
Filed: |
March 9, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10904071 |
Oct 21, 2004 |
|
|
|
12400024 |
|
|
|
|
Current U.S.
Class: |
166/381 ;
166/65.1; 166/66.4 |
Current CPC
Class: |
E21B 47/00 20130101;
E21B 43/04 20130101; E21B 41/0085 20130101 |
Class at
Publication: |
166/381 ;
166/65.1; 166/66.4 |
International
Class: |
E21B 28/00 20060101
E21B028/00; E21B 43/00 20060101 E21B043/00; E21B 23/00 20060101
E21B023/00; E21B 41/00 20060101 E21B041/00 |
Claims
1. A system usable with a subterranean well, comprising: a downhole
component located in the subterranean well to receive power and
perform a downhole function in response to the received power, and
a power generator located downhole in proximity to the downhole
component to respond to vibrational energy from the downhole
component to generate part of the power received by the downhole
component.
2. The system of claim 1, wherein the downhole component comprises
at least one of an electrical submersible pump, a rod pump, or a
beam pump.
3. The system of claim 1, wherein the downhole component is located
within approximately ten feet of the power generator.
4. The system of claim 1, wherein the power generator is a flexible
member with a natural frequency substantially matching the
vibrational energy of the downhole component.
5. A system usable with a subterranean well, comprising: a downhole
component located in the subterranean well to receive power and
perform a downhole function in response to the received power; a
power generator located downhole in proximity to the downhole
component to respond to vibrational energy from the downhole
component to generate part of the power received by the downhole
component; and a power storage device used to provide another part
of the power received by the downhole component.
6. The system of claim 5, wherein the downhole component comprises
at least one of an electrical submersible pump, a rod pump, or a
beam pump.
7. The system of claim 5, wherein the downhole component is located
within approximately ten feet of the power generator.
8. The system of claim 5, wherein the power generator is a flexible
member configured with a natural frequency substantially matching
the vibrational energy of the downhole component.
9. A method usable with a subterranean well, comprising: placing a
downhole component at a location within the subterranean well;
providing a power generator proximate to the downhole component;
configuring the power generator to respond to vibrational energy
produced by the downhole component to generate part of the power
received by the downhole component; providing a power storage
device configured to provide another part of the power received by
the downhole component.
10. The method of claim 9, wherein the downhole component comprises
at least one of an electrical submersible pump, a rod pump, or a
beam pump.
11. The method of claim 9, wherein the power generator is located
within approximately ten feet of the downhole component.
Description
RELATED APPLICATIONS
[0001] This application is a divisional of and claims the benefit
of U.S. application Ser. No. 10/904,071, titled "HARVESTING
VIBRATION FOR DOWNHOLE POWER GENERATION," filed Oct. 21, 2004, the
contents of which are herein incorporated by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The invention generally relates to harvesting vibration for
downhole power generation.
[0004] 2. Description of the Related Art
[0005] The following descriptions and examples are not admitted to
be prior art by virtue of their inclusion in this section.
[0006] A typical subterranean well includes various devices that
are operated by mechanical motion, hydraulic power or electrical
power. For devices that are operated by electrical or hydraulic
power, control lines and/or electrical cables typically extend
downhole for purposes of communicating power to these tools from a
power source that is located at the surface. A potential challenge
with this arrangement is that the space (inside the wellbore) that
is available for routing various downhole cables and hydraulic
control lines may be limited. Furthermore, the more hydraulic
control lines and electrical cables that are routed downhole, the
higher probability that some part of the power delivery
infrastructure may fail. Other risks are inherent in maintaining
the reliability of any line or cable within the well's hostile
chemical, mechanical or thermal environment and over the long
length that may be required between the surface power source and
the downhole power operated device.
[0007] Thus, some subterranean wells have tools that are powered by
downhole power sources. For example, a fuel cell is one such
downhole power source that may be used to generate electricity
downhole. The subterranean well may include other types of downhole
power sources, such as batteries, for example.
[0008] A typical subterranean well undergoes a significant amount
of vibration (vibration on the order of Gs, for example) during the
production of well fluid. In the past, the energy produced by this
vibration has not been captured. However, an emerging trend in
subterranean wells is the inclusion of devices to capture this
vibrational energy for purposes of converting the energy into a
suitable form for downhole power.
[0009] Thus, there is a continuing need for better ways to generate
power downhole in a subterranean well.
SUMMARY
[0010] In an embodiment of the invention, a system that is usable
with a subterranean well includes a winding, a member and a
circuit. The winding is located downhole in the well, and the
member moves relative to the winding in response to vibration
occurring in the well to cause a signal to be generated on the
winding. The circuit is coupled to the winding to respond to the
signal to provide power to operate a component located downhole in
the well.
[0011] Advantages and other features of the invention will become
apparent from the following description, drawing and claims.
BRIEF DESCRIPTION OF THE DRAWING
[0012] Certain embodiments of the invention will hereafter be
described with reference to the accompanying drawings, wherein like
reference numerals denote like elements. It should be understood,
however, that the accompanying drawings illustrate only the various
implementations described herein and are not meant to limit the
scope of various technologies described herein. The drawings are as
follows:
[0013] FIG. 1 is a schematic diagram of a well according to an
embodiment of the invention;
[0014] FIG. 2 is a flow diagram depicting a technique to generate
downhole power according to an embodiment of the invention;
[0015] FIGS. 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 and 14 depict
mechanisms to enhance the generation of downhole vibrational energy
according to an embodiment of the invention;
[0016] FIG. 15 depicts a system located on a sandscreen to aid in
the generation of downhole power according to an embodiment of the
invention;
[0017] FIG. 16A is a flow diagram depicting a technique to power
wireless tags according to an embodiment of the invention;
[0018] FIG. 16B depicts a system to deploy wireless tags according
to an embodiment of the invention;
[0019] FIG. 17 is a schematic diagram of a wireless tag according
to an embodiment of the invention;
[0020] FIG. 18A is a block diagram of a system to harness and store
vibrational energy downhole according to an embodiment of the
invention;
[0021] FIG. 18B depicts a piezoelectric material based vibration
energy converter;
[0022] FIG. 19A is a block diagram of an electromagnetic based
system to harness and store vibrational energy downhole according
to an embodiment of the invention;
[0023] FIG. 19B depicts an electromagnetic based vibration energy
converter;
[0024] FIGS. 20A, 20B and 20C are schematic diagrams of vibrational
energy harvesting mechanisms according to an embodiment of the
invention;
[0025] FIG. 21 is a schematic diagram of a portion of a drilling
string according to an embodiment of the invention;
[0026] FIG. 22 is a schematic diagram of a subsea well according to
an embodiment of the invention;
[0027] FIG. 23 is a flow diagram depicting a technique to power a
downhole tool according to an embodiment of the invention;
[0028] FIG. 24 is a flow diagram depicting a technique to use
vibration in a cementing operation according to an embodiment of
the invention;
[0029] FIG. 25 is a flow diagram depicting a technique to evaluate
potential blockage of a downhole pipe according to an embodiment of
the invention;
[0030] FIG. 26 is a flow diagram depicting a technique to
communicate with a downhole tool according to an embodiment of the
invention;
[0031] FIG. 27 is a schematic diagram depicting a system in which
vibrational energy is used to communicate with downhole tools
according to an embodiment of the invention; and
[0032] FIGS. 28, 29 and 30 are schematic diagrams of mechanisms to
harness vibrational energy to generate electrical power according
to embodiments of the invention.
DETAILED DESCRIPTION
[0033] In the following description, numerous details are set forth
to provide an understanding of the present invention. However, it
will be understood by those of ordinary skill in the art that the
present invention may be practiced without these details and that
numerous variations or modifications from the described embodiments
may be possible. In the specification and appended claims: the
terms "connect", "connection", "connected", "in connection with",
"connecting", "couple", "coupled", "coupled with", and "coupling"
are used to mean "in direct connection with" or "in connection with
via another element"; and the term "set" is used to mean "one
element" or "more than one element". As used herein, the terms "up"
and "down", "upper" and "lower", "upwardly" and downwardly",
"upstream" and "downstream"; "above" and "below"; and other like
terms indicating relative positions above or below a given point or
element are used in this description to more clearly describe some
embodiments of the invention.
[0034] Referring to FIG. 1, an embodiment 10 of a well in
accordance with the invention includes a tubular string 14 (a
production string, for example) that extends into a wellbore of the
well 10. The tubular string 14 may include a central passageway 29
that communicates a flow 27 from a subterranean formation zone 32
(or to a formation zone in the case of an injection well). The zone
32 represents one out of many possible zones of the well 10. The
zone 32 may be defined (i.e., isolated from other zones) by one or
more packers 30 (one being depicted in FIG. 1).
[0035] The flow 27 is a primary source of vibrational energy
downhole, and this vibrational energy is captured by a vibrational
energy harvesting mechanism 20 (of a power generation tool 18) for
purposes of converting the vibrational energy into downhole
electrical power. This electrical power, in turn, may be used to
power one or more downhole power-consuming components, such as
sleeve valves, ball valves, motors, actuators, sensors, sound
sources, electromagnetic signaling sources, or equipment to fire
"smart bullets" into a well casing, perforating gun firing heads,
controllers, microprocessors, Micro Electrical Mechanical Sensors
(MEMS), telemetry systems (transmitters or receivers), etc.,
depending on the particular embodiment of the invention.
[0036] In some embodiments of the invention, the string 14 includes
one or more features to enhance the generation of vibrational
energy, referred to generally herein as a "vibration enhancement
mechanism 16." More specifically, the flow 27 enters the mechanism
16 that, in some embodiments of the invention, produces a locally
more turbulent flow 31 that flows uphole. The creation of this more
turbulent flow, in turn, amplifies the vibrational energy, thereby
leading to the increased production of downhole power. The
vibrational harvesting mechanism 20 may be located in proximity to
(within ten feet, for example) to the vibration enhancing mechanism
16, in some embodiments of the invention. Various embodiments of
the vibration enhancing mechanism are described below.
[0037] Thus, referring to FIG. 2, in some embodiments of the
invention, a technique 40 may be used to harvest vibrational energy
downhole. More specifically, in accordance with the technique 40,
the downhole vibration is enhanced (block 42) such as by the
vibration enhancement mechanism 16, as further described below.
Next, pursuant to the technique 40, the downhole vibration is
converted (block 44) into downhole power to power one or more
downhole power-consuming devices.
[0038] As a more specific example, FIG. 3 depicts a cross-section
of a vibration enhancing mechanism 50 in accordance with an
embodiment of the invention. The device 50 may be formed from a
section of the string 14 having an interior wall 15 that constricts
the central passageway 29 of the string 14. More specifically, in
some embodiments of the invention, the section has a circular
cross-section of varying diameter; and in some embodiments of the
invention, the section forms a Venturi-type flow path. This flow
path, in turn, converts the entering flow 27 into a more turbulent
flow 31 for purposes of creating more vibration. The flow path of
the device 50 thus creates vibrational energy that is harvested by
the power generator tool 18.
[0039] Other types of vibration enhancing mechanisms may be used in
other embodiments of the invention. For example, referring to a
cross-section depicted in FIG. 4, in some embodiments of the
invention, a cantilevered member 56 may extend from the interior
wall 15 of the string 14 into the central passageway 29. The member
56 introduces an obstruction in the flow path 27 to create the more
turbulent flow 31.
[0040] As another example, FIG. 5 depicts a cross-sectional view of
a vibration-enhancing mechanism 60 that contains a flexible member
62 that has one end that is attached to the interior wall 15 of the
tubular string 14 and another free end that extends into the
central passageway 29. Due to this arrangement, the flexible member
62 moves in response to the flow 27 to create the more turbulent
flow 31 and thus, enhance the generation of vibrational energy.
[0041] As another example, FIG. 6 depicts a cross-sectional view of
a vibration-enhancing mechanism 66 that, similar to the
Venturi-type flowpath of the mechanism 50 (FIG. 3), includes a
restricted flow path 68 for purposes of increasing vibration
downhole. In some embodiments of the invention, the flow path 68
has a circular cross-section section that varies in diameter.
[0042] It has been discovered that a production string (a possible
embodiment of the tubing string 14 (FIG. 1)) has a fundamental
vibration mode in which the cross-section of the production string
expands and contracts in two orthogonal cross-sectional directions.
For example, as depicted in a cross-section of a production tubing
section in FIG. 7, during the flow of fluid through a production
tubing string, the string may include a cross-section that expands
in the positive and negative Y directions while the cross-section
of the production tubing contracts in the positive and negative X
directions. Next, pursuant to the fundamental vibration mode, the
cross-section of the production tubing expands in the positive and
negative X directions and contracts in the positive and negative Y
directions. This process repeats to establish the fundamental
vibration mode.
[0043] As depicted in FIG. 7, in some embodiments of the invention,
the thickness of the wall of the production string 70 may be
radially varied to select the axis and otherwise enhance the
fundamental vibration mode. More specifically, the cross-section of
the string may include thinner portions 72 that extend along the
X-axis and thinner portions 74 that extend along the Y-axis. The
remaining portions 76 of the cross-section are thicker. Thus, due
to this arrangement, the flexing of the production string 70 in the
above-described cross-sectional directions is enhanced due to the
thinning of the production tubing string cross-section in
orthogonal directions. Increasing the flexing of the production
tubing string, in turn, enhances the vibrational energy that is
generated by the flow of fluids through the production tubing
string. Thus, the arrangement that is depicted in FIG. 7 enhances
the vibrational energy that is converted into electrical energy
downhole.
[0044] As another example of a mechanism to enhance vibrational
energy downhole, FIG. 8 depicts a mechanism 80 that includes a
spring 81 that may be attached to, for example, the interior wall
15 of the string 14 and extend into the central passageway 29. In
yet another embodiment of the invention, a vibration enhancing
mechanism 84 (a cross-section of which is depicted in FIG. 9)
includes a wedge-shaped flow diverter 86 that is inserted into the
flow path 27 for purposes of creating a more turbulent flow. As
depicted in FIG. 9, regions 88 exist between the diverter 86 and
the wall of the string 14 for purposes of allowing fluid to pass
therethrough. However, the flow diverter 86 introduces additional
turbulence into the flow 27, thereby creating additional vibration
downhole.
[0045] In some embodiments of the invention, a piece of downhole
equipment that may already be located downhole may be strategically
placed near the power generation tool 20 (FIG. 1) for purposes of
enhancing vibration near the tool 20. For example, referring to
FIG. 10, a multiphase mixer 86 may be placed in close proximity
(within ten feet for example) to the power generation tool 20. The
multiphase mixer 86, as its name implies, typically is used in
production to blend various phases of well fluid together. The
mixer 86 may include, for example, an opening 102 that receives the
flow 27. The mixer 86 may also include an internal chamber 99 that
includes various orifices 100 through which the flow may proceed to
flow upstream and produce the flow 31 through the central
passageway 29.
[0046] In other embodiments of the invention, a vibrational
energy-enhancing mechanism 108 (a cross-section of which is
depicted in FIG. 11) may be used. The mechanism 108 includes a
blind T 112 that is inserted into the flow path 27. The blind T 112
is surrounded by openings 110 that permit the flow of the fluid
around the blind T 112. However, the inclusion of the blind T 112
in the flow path 27 creates turbulence that, in turn, enhances the
vibrational energy downhole.
[0047] Referring to FIG. 12, in some embodiments of the invention,
a vibration-enhancing section 120 of the string 15 may include a
spiral or helical groove 124 that extends along the inner surface
of the wall 15 of the string 14. As depicted in FIG. 12, the
longitudinal axis of the groove 124 is concentric with the
longitudinal axis of the string 14.
[0048] In some embodiments of the invention, a free flowing part
may be used to enhance the generation of vibrational energy
downhole. For example, a vibration enhancing mechanism 130 (a
cross-section of which is depicted in FIG. 13) may include a
chamber 132 (in the flow path 27) that contains a ball 140.
Analogous to a policeman's or an umpire's whistle, the ball 140 is
trapped inside the chamber 132, in that lower 139 and upper 135
openings in the chamber 132 are sized to permit fluid (but not the
ball 140) to pass into and out of the chamber 132 and contact the
ball 140. The interaction of the fluid with the ball 140 creates
vibrational energy that may be harvested for electrical power.
[0049] In some embodiments of the invention, an electrical device
that consumes harvested power downhole may also be used to generate
vibrational energy used for purposes of power generation. For
example, as depicted in FIG. 14, in some embodiments of the
invention, a vibration-enhanced mechanism 150 may include an
electrical pump 152 (a beam-type pump, a rod-type pump or an
electrical submersible pump (ESP)), as just a few examples. The
electrical pump 152 receives the flow 27 to produce the output flow
31. The operation of and fluid flow through the pump 152 enhances
the vibrational energy.
[0050] Although the vibration-enhancing mechanisms and power
generating mechanisms (such as the power generator tool 18) that
are described above are generally located in the central passageway
of the string 14, it is noted that in other embodiments of the
invention, these mechanisms may be located in other regions of the
well. For example, in some embodiments of the invention, these
mechanisms may be located on the outside of the string 14 or
located in a side packet mandrel, as further described below in
connection with FIG. 22.
[0051] As a more specific example, referring to FIG. 15, in some
embodiments of the invention, a vibration-enhancing mechanism 160
may be located on the outside of a sandscreen 158. Thus, the
mechanism 160, which may be any of the above-described mechanisms,
may be located in a flow path located between the exterior and the
interior of the sandscreen 158. In some embodiments of the
invention, the mechanism 160 may be located inside the sandscreen
158. Furthermore, in some embodiments of the invention, a power
generator (not shown) to generate electrical power from vibrational
energy may be mounted to the sandscreen 158 and may be located
either on the outside or inside of the sandscreen 158.
[0052] Although in the embodiments described above, the power
generation mechanism 20 is depicted (FIG. 1) as being attached to
the string 14, in other embodiments of the invention, the power
generation mechanism 20 may not be fixed in position relative to
the string 14. For example, in some embodiments of the invention, a
wireless (a radio frequency (RF), for example) tag may be used to
measure various properties in a subterranean well. These properties
may include, for example, detection of water or chemical
constituents, such as hazardous H2S, or measurement of pressure and
temperatures at various positions in the well. The tag may be
free-flowing, in that the tag may be released into the well and
take a measurement at a particular depth in the well. Many
variations are possible. For example, the tag may be activated at a
particular depth, a particular temperature, a particular pressure,
etc.
[0053] For purposes of supplying power to the tag, the tag may
derive its power from the vibrational forces that are experienced
by the tag itself. Thus, instead of being attached to a static
structure, such as the string 14, for example, the tag is
free-flowing and is imparted with vibrational energy as the tag
flows in the well. This vibrational energy, is converted by a
vibrational energy transformer of the tag into electrical power for
the tag.
[0054] Thus, referring to FIG. 16A, in some embodiments of the
invention, a technique 180 includes deploying (block 182) wireless
tags in a subterranean well. Vibrational energy is used (block 184)
to activate (i.e., power up and continue providing power to) the
tags. Once activated, measurements are then performed (block 186)
with the tags.
[0055] FIG. 16B depicts a subterranean well 200 in accordance with
the technique 180. As shown in FIG. 16B, the well 200 may include a
tubular string 204 (a production tubing, for example) into which
several tags 220 have been placed into the central passageway of
the well 200. As an example, the well 200 may include a surface
pump 206 that may control the flow of fluid through the well 200.
For example, the pump 206 may halt fluid flow through the string
204 to allow the tags 220 to descend into the well 200. When the
tags have collected the data, the pump 206 may then be re-activated
to cause fluid to flow uphole and thus return the tags 220 toward
the surface.
[0056] In some embodiments of the invention, the well 200 may
include a tag reader 230 to extract information from the tags 220
as the tags 220 return from downhole. As the tags 220 descend
downhole, vibrational energy imparted on the tags 220 generate
power on the tag 220 to activate the tag 220 so that the tag 220
may then take the appropriate measurement downhole.
[0057] Referring to FIG. 17, in some embodiments of the invention,
the tag 220 may have an architecture that is generally depicted in
FIG. 17. This architecture may include, for example, a processor
248 that is coupled to a sensor 250 (a pressure or temperature
sensor, for example) through a bus 249. The processor 248 may
execute instructions that are stored in a memory 244 (also coupled
to the bus 249) as well as store data from the sensor 250 in the
memory 244. The architecture may include various other features,
such as a transmitter to transmit to the reader 230 (FIG. 16B),
depending on the particular embodiment of the invention.
[0058] As depicted in FIG. 17, the tag 220 includes power
generation circuitry that includes, for example, a vibrational
energy converter 240. As its name implies, the converter 240
produces a voltage (for example) in response to vibrational energy
that occurs to the tag 220. A DC-to-DC converter 242 converts this
voltage into a regulated voltage that appears on voltage supply
lines 246. The voltage supply lines 246, in turn, furnish power to
the various components of the tag 220, such as the sensor 250,
processor 248 and memory 244, as just a few examples.
[0059] In some embodiments of the invention, the tag 220 may
include a reserve energy source, such as a battery 245, that is
coupled to the output terminals of the DC-to-DC converter 242. The
battery 244 serves as an energy buffer to store excess energy that
is provided by the converter 240 so that this energy may be used to
regulate the power that is provided to the power-consuming
components of the tag 220.
[0060] In some embodiments of the invention, the power harvesting
circuitry (whether on a wireless tag or affixed to the string 14)
may have an architecture 260 that is generally depicted in FIG.
18A. This architecture 260 includes a vibration responsive strain
inducer 264. As examples, the vibration responsive strain inducer
264 produces a mechanical force that, as its name implies, imparts
a physical strain on a piezoelectric material 262. A piezoelectric
material, by its very nature, produces a terminal voltage
responsive to the strain that is induced on the material.
Therefore, in response to the strain produced by the inducer 264,
the piezoelectric material 262 produces a voltage that appears on a
signal line 266. This voltage, in turn, is regulated to a specific
DC level by a DC-to-DC converter 268 to produce a regulated voltage
that appears on a power supply 270.
[0061] Thus, the inducer 264, piezoelectric material 262 and
converter 268 form a basic power-harvesting generator 273 in
accordance with an embodiment of the invention.
[0062] Although depicted in FIG. 18A as producing DC power, it is
noted that in other embodiments of the invention, the generator 273
may include an inverter for purposes of generating an AC voltage.
Thus, other embodiments are within the scope of the following
claims.
[0063] Additionally, in some embodiments of the invention, a
particular well may include several generators 275 that are
connected in parallel to the supply 270. Furthermore, in some
embodiments of the invention, a battery 272 may be coupled to the
voltage supply line 272 for purposes of serving as an energy buffer
to absorb and supply power, depending on the particular vibrational
energy being experienced at the time.
[0064] In accordance with an embodiment of the invention, the
vibration responsive strain inducer 264 and piezoelectric material
262 may, in some embodiments of the invention, have a form 280 that
is depicted in FIG. 18B. More specifically, the arrangement 280 may
include a piezoelectric material 282 that is located between fairly
rigid members 286 and 284. These members may be formed from, as
examples, part of housing of the string 14 as well as explicit
plates. A cantilevered mass 290 is connected to the plates 284 and
286 to exert a strain force on the piezoelectric material 282 in
response to the vibrational energy sensed by the mass 290. Thus,
vibrational energy causes movement of the mass 290, and this
movement, in turn, induces stress to cause the piezoelectric
material to generate a corresponding voltage.
[0065] Referring both to FIGS. 19A and 19B, in some embodiments of
the invention, the power harvesting circuitry (whether on a
wireless tag or affixed to the string 14) may have an architecture
260 that is generally depicted in FIG. 19A. This architecture 260
includes a vibration responsive strain inducer 264. As examples,
the vibration responsive strain inducer 264 produces a mechanical
force that, as its name implies, imparts a physical strain on an
electromechanical energy conversion, or generator, that is
depicted, as an example, in FIG. 19B. An electromagnetic energy
converter, by its very nature, produces a terminal voltage induced
by an electrical conductor, or coil, moving in a magnetic field
that is maintained by a suitable ferro-magnetic material, permanent
magnet. Therefore, in response to the strain or motion produced by
the inducer 264, the electromagnetic converter produces a voltage
that appears on a signal line 266. This voltage, in turn, is
regulated to a specific DC level by a DC-to-DC converter 268 to
produce a regulated voltage that appears on a power supply 270.
[0066] In the various embodiments of the invention, the mass that
induces the strain on the piezoelectric material may not be a
cantilevered mass but alternatively, may be another type of strain
inducer that generates a strain on the piezoelectric material in
response to vibrational energy. For example, in some embodiments of
the invention, the wall of the tubular string 14 (see FIG. 1) may
be lined with a piezoelectric coating 304, as depicted in FIG. 20A.
More specifically, the piezoelectric material lining 304 may
completely or partially coat the interior wall of the tubular
string 14, according to the particular embodiment of the invention.
Due to the above-described fundamental mode of vibration of the
tubular string 14, this vibration induces a strain on the
piezoelectric material coating 304 to generate a corresponding
voltage across the material 304.
[0067] Although not depicted in FIG. 20A, in some embodiments of
the invention, a thin insulation layer may be interposed between
the lining 304 and the interior surface of the tubing string wall
for purposes of isolating the terminal voltage appearing on the
coating 304 from the tubing string 14.
[0068] As another example of a strain-inducing mechanism in
accordance with the invention, FIG. 20B depicts a mechanism 304
that includes a flexible flow member 62 (see FIG. 5) that has a
piezoelectric electric coating 308 lining the flexible member 62.
Thus, the motion of the flexible member 62 induces a strain on the
material 308 to generate a voltage on the material 308.
[0069] Thus, as can be seen, the piezoelectric coating may be
applied to various downhole components that are subject to
vibration, in that the vibration induces a strain on the
piezoelectric coating, and this strain induces a voltage that may
be converted into downhole power. As yet another example, FIG. 20C
depicts the blind T 112 (see FIG. 11) that is at least partially
covered by a piezoelectric coating 311. Thus, other variations are
possible and are within the scope of the appended claims.
[0070] Due to the generation of electrical power downhole, various
control lines and electrical cables do not need to be extended from
the surface of the well. Furthermore, generating electrical power
downhole may be advantageous for purposes of reducing cabling
between downhole components. For example, FIG. 21 depicts a drill
string 320 that includes a mud motor 324 and a drill bit 328. The
drill string 320 may include sensors 326 that are used for purposes
of monitoring operation of the drill string 320 and monitoring
general operation of the drilling. The sensors 326 typically are
located close to the drill bit 328. A particular challenge with
this arrangement is that the sensors 326 may be located away from a
power source and thus, electrical cables may have to span across
the mud motor 324 for purposes of delivering power to the sensors
326. However, in accordance with embodiments of the invention, the
sensors 326 may be in close proximity to power generation circuitry
324 that generates electrical power from the vibration of the drill
string 320, such as the vibration that occurs during operation of
the mud motor 324. Due to this arrangement, cabling does not have
to be extended across the mud motor 324 for purposes of delivering
power to the sensors 326.
[0071] Referring back to FIG. 1, as another example of the
reduction of cabling due to the generation of power downhole, the
well 10 may include an intelligent completion, a completion that
contains circuitry that automatically controls downhole equipment
independently from any commands that are communicated from the
surface of the well. For example, the string 14 may be a production
string and include a valve 21 (a sleeve valve or ball valve, as
examples) that is electrically operated by power that is produced
by the power generator tool 18. An intelligent controller 23 of the
string 14 may, for example, use a sensor 11 (also of the string 14)
to detect one or more characteristic(s) of the flow 27. The sensor
11 may include one or more of a pressure sensor, a temperature
sensor, a fluid composition sensor and a Micro Electrical
Mechanical Sensor (MEMS), depending on the particular embodiment of
the invention.
[0072] Based on the detected characteristic(s), the controller 23
operates a valve 21 (a sleeve valve or ball valve, as examples) to
control the flow 27. For example, the controller 23 may determine
the flow 27 has a high water content level and close the valve 21
to shut off flow from the zone 32. As another example, the
controller 23 may also control the valve 21 to regulate a pressure
in the well. The controller 23, sensor 11 and valve 21, in some
embodiments of the invention, receive power from the power
generator tool 18. In some embodiment of the invention, the
controller 23, sensor 11 and valve 21 receive all of their
operating power from the power generating tool 18.
[0073] As another example of a power consuming device that may rely
on energy derived from vibrational energy downhole, FIG. 22 depicts
a subsea well 400 that extends beneath a sea floor 402. The subsea
well 400 includes a subsea well tree and wellhead 404; and a
tubular string 406 that extends into a wellbore of the well. A
robot 414 may be located inside the tubular string 406. The robot
414 may generally be autonomous in that the robot 414 does not rely
on a tethered connection for purposes of operating in the subsea
well to perform an intervention, for example. Thus, for purposes of
generating power, robot 414 may dock to power connectors that are
electrically coupled to a power generation mechanism 410 that
generates downhole electrical power from vibrational energy.
[0074] As an example, the power generation mechanism 410 may be
located in a side pocket mandrel 412 that is formed in the tubing
406. As shown in FIG. 2, due to the inclusion of the power
generating mechanism 410 and the side pocket mandrel 412, the
central passageway of the tubing string 406 is unobstructed for
purposes of operating the robot 410, performing an intervention
with other tools, producing well fluid, etc.
[0075] The subsea well 400 may include other components that are
powered by the power generating mechanism 410, such as, for
example, telemetry circuitry 420 that is located on the sea floor
402 and is used to communicate (via acoustic, optical or
electromagnetic communication, as examples) with a surface platform
(not shown in FIG. 22). The power generating mechanism 410 may also
deliver power (via communication lines 425) to electrical storage
424 (a battery, for example) that is located on the sea floor
402.
[0076] The above-described arrangements rely on the vibrational
forces that are produced either by downhole equipment or by the
flow of well fluid in contact with a particular vibration-enhancing
mechanism. However, in some embodiments of the invention,
vibrations may be intentionally introduced into a fluid or slurry
that is introduced downhole from the surface.
[0077] For example, FIG. 23 depicts an embodiment of a technique
430 in accordance with the invention, which uses vibrations in a
gravel pack flow for purposes of communicating vibrational energy
downhole that may be used to produce downhole power. More
specifically, in accordance with the technique 430, vibrations are
induced in a gravel packed flow, as depicted in block 432. For
example, these vibrations may be induced by pressure pulses that
are applied to a slurry flow as well as less regulated vibrational
energy that is applied to the flow. Regardless of the specific form
of the vibrational energy, the vibrational energy is applied at the
surface of the well and is communicated downhole via the flow.
Pursuant to the technique 430, this vibrational energy is used
(block 434) to generate downhole power, such as for a downhole tool
to be used during or after the completion of gravel packing (for
example).
[0078] Referring to FIG. 24, other types of downhole flows may be
used for purposes of communicating vibrational energy downhole. For
example, FIG. 24 depicts a technique 444 for purposes of
communicating vibrational energy via a cement flow. Pursuant to the
technique 444, a vibration is introduced in the cement flow, as
depicted in block 446. Similar to the gravel packed flow discussed
in connection with FIG. 23, vibrational energy may be imparted to
the cement flow by, for example, pulses or other types of
vibrational energy. This vibrational energy is then used to
generate power downhole (as depicted in block 450) for one or more
downhole tools.
[0079] Not only may the vibrational energy be used to produce
downhole power, other uses of the vibrational energy may be used,
in accordance with particular embodiments of the invention. For
example, FIG. 25 depicts a technique 470 for purposes of using
vibrational energy to detect problems with tubular passageways
(production tubing passageways, gravel packing shunt tubes, etc.)
downhole. In this manner, pursuant to the technique 470,
vibrational energy is detected (block 472) downhole and then used
to evaluate (block 474) possible blockage in response to the
detected energy. The vibrational energy may be generated downhole
(in response to a fluid flow, for example) and/or may be
communicated downhole by a flow (a cement or gravel packing flow,
as examples) from the surface of the well. As a more specific
example, in some embodiments of the invention, a circuit may
analyze the spectral components of the produced vibrational energy
and based on comparing the computed spectral energy to reference
patterns, may determine whether or not a blockage exists in a
particular downhole member.
[0080] As yet another example of the use of vibrational energy to
perform a function other than solely being converted into downhole
power, a technique 481, depicted in FIG. 26, uses vibrational
energy for purposes of communicating with the downhole tool. More
specifically, pursuant to the technique 481, vibrational energy is
detected (block 482) downhole, and this detection is used (block
484) to handshake, that is to communicate commands and/or
measurements with a specific downhole tool.
[0081] As a more specific example, FIG. 27 depicts a well 500 in
accordance with the invention that includes a tubular string 582
that extends into a wellbore of the well 500. The string 582
includes gas lift valves 584 that may be used for purposes of
injecting gas for purposes of lifting production fluid uphole. A
circuit 590 on the surface of the well 500 monitors vibrational
energy that is generated by the gas lift valves 584 for purposes of
determining when a particular gas lift valve 584 has been
activated. In this regard, in some embodiments of the invention,
each gas lift valve 584 may be designed to have a unique and
identifiable resonant frequency when activated. This vibrational
frequency, in turn, is detected by the circuit 590 for purposes of
identifying when the gas lift valve 584 has activated.
[0082] Alternatively, in some embodiments of the invention, each
gas lift valve 584 may be designed to release tags that contain a
unique and identifiable code that can be communicated to a suitable
circuit at the surface located as 590 in FIG. 27.
[0083] Other embodiments are within the scope of the following
claims. For example, many other techniques may be used to generate
electric power from vibrational energy downhole. For example, in
some embodiments of the invention, a capacitor may be used that has
at least one plate that is mounted to a spring. A voltage may be
stored on the capacitor so that by variation of the distance
between the plates of the capacitor, a varying voltage is produced.
This varying voltage, in turn, may be converted into power for a
particular downhole tool.
[0084] As another example of a mechanism to generate power from
downhole vibrational energy, FIG. 28 depicts, as a variation on the
electromagnetic energy converter depicted in FIG. 19B a mechanism
600 that includes a coil 602 that generally circumscribes a
magnetically-charged ferrous material 610. The material 610, in
turn, may be mounted on springs 606 to move longitudinally along
the axis of the coil 602, as depicted in FIG. 28. This movement of
the material 610, in turn, produces a voltage on the coil 602 and
this voltage may be converted into downhole power. In some
embodiments of the invention, the coil 602 may be embedded in a
mandrel 604 that generally circumscribes the ferrous material
610.
[0085] In another variation, FIG. 29 depicts a power generation
mechanism 620 in which the mandrel 604 (that contains the coil 602)
moves instead of the ferrous material 610. More specifically, the
ferrous material 610 may be relatively stationary; and the mandrel
604 is mounted on springs 624. Thus, vibration causes movement of
the mandrel 604 (and coil 602) with respect to the ferrous material
610. This movement, in turn, induces a voltage on the coil 602, and
this voltage may be used to generate power downhole. It is noted
that many other variations are possible in the various embodiments
of the invention. For example, FIG. 30 depicts a mechanism 650
similar to the mechanism 600 except that the ferrous material 610
is mounted via springs 651 so that the ferrous material 610 moves
laterally with respect to the coil 602. This lateral movement, in
turn, changes the magnetic permeability of the path inside the coil
602 to change the voltage that appear on the coil's terminals. As
depicted in FIG. 30, in some embodiments of the invention, the
spring 651 may couple the ferrous material 610 to the inner
side-walls of the mandrel 604.
[0086] Other variations are possible. For example, in other
embodiments of the invention, the ferrous material 610 may be
distributed on a dynamo that rotates inside the coil 602 to
generate voltage on the coil's terminals. The rotational speed of
the dynamo increases with the level of vibration in the well.
[0087] While the present invention has been described with respect
to a limited number of embodiments, those skilled in the art,
having the benefit of this disclosure, will appreciate numerous
modifications and variations therefrom. It is intended that the
appended claims cover all such modifications and variations as fall
within the true spirit and scope of this present invention.
* * * * *