U.S. patent application number 11/728760 was filed with the patent office on 2008-10-02 for piezoelectric resonant power generator.
Invention is credited to Jason J. Barnard, Robert S. O'Brien.
Application Number | 20080238252 11/728760 |
Document ID | / |
Family ID | 39591301 |
Filed Date | 2008-10-02 |
United States Patent
Application |
20080238252 |
Kind Code |
A1 |
Barnard; Jason J. ; et
al. |
October 2, 2008 |
Piezoelectric resonant power generator
Abstract
A power generation system includes a piezoelectric component, a
resilient stress inducer in operable communication with the
piezoelectric component, and an actuator in operable communication
with the resilient stress inducer to energize and release the
resilient stress inducer and method for generating power.
Inventors: |
Barnard; Jason J.; (Katy,
TX) ; O'Brien; Robert S.; (Katy, TX) |
Correspondence
Address: |
CANTOR COLBURN, LLP
20 Church Street, 22nd Floor
Hartford
CT
06103
US
|
Family ID: |
39591301 |
Appl. No.: |
11/728760 |
Filed: |
March 27, 2007 |
Current U.S.
Class: |
310/319 ;
310/328 |
Current CPC
Class: |
E21B 41/0085 20130101;
H02N 2/18 20130101 |
Class at
Publication: |
310/321 ;
310/328 |
International
Class: |
H02N 2/18 20060101
H02N002/18; H01L 41/113 20060101 H01L041/113 |
Claims
1. A power generation system comprising: a piezoelectric component;
a resilient stress inducer in operable communication with the
piezoelectric component; and an actuator in operable communication
with the resilient stress inducer to energize and release the
resilient stress inducer.
2. The power generation system as claimed in claim 1 wherein the
resilient stress inducer imparts a compressive stress on the
piezoelectric component.
3. The power generation system as claimed in claim 1 wherein the
system further includes a capacitor electrically connected to the
piezoelectric component to store potential energy generated by the
piezoelectric component.
4. The power generation system as claimed in claim 1 wherein the
resilient stress inducer is a coil spring.
5. The power generation system as claimed in claim 1 wherein the
system comprises a second resilient stress inducer arranged so as
to place one of the resilient stress inducer and the second
resilient stress inducer in compression while the other of the
resilient stress inducer and the second resilient stress inducer is
placed in tension.
6. The power generation system as claimed in claim 1 wherein the
resilient stress inducer imposes a mechanical stress on the
piezoelectric component when under compression and when under
tension.
7. The power generation system as claimed in claim 1 wherein the
system further comprises a magnetic element operably connected to
the resilient stress inducer and which magnetically interfaces with
the actuator.
8. The power generation system as claimed in claim 7 wherein the
actuator is a sucker rod manipulated by a pump jack, the sucker rod
having a magnetic element thereon attractively polarized relative
to the magnetic element connected to the resilient stress
inducer.
9. The power generation system as claimed in claim 1 wherein the
piezoelectric component is two such components located spaced apart
and axially aligned, the resilient stress inducer being disposed
therebetween.
10. A method for generating power in a wellbore comprising: moving
an actuator; inducing an oscillating stress on a piezoelectric
component with the actuator; and generating a voltage with the
piezoelectric component in response to the induced stress on the
piezoelectric component.
11. The method of generating power in a wellbore of claim 10
wherein the inducing is by energizing a resilient stress
inducer.
12. The method of generating power in a wellbore of claim 11
wherein the method further comprises allowing the resilient stress
inducer to oscillate after being released from energizing.
13. The method of generating power in a wellbore of claim 12
wherein the oscillation of the resilient stress inducer causes
mechanical stress on the piezoelectric component.
14. The method of generating power in a wellbore of claim 10
wherein the method further includes storing the voltage
generated.
15. The method of generating power in a wellbore of claim 14
wherein the storing is in a capacitor electrically connected to the
piezoelectric component.
16. The method of generating power in a wellbore of claim 11
wherein the energizing is by moving a magnetic element to
magnetically couple with another magnetic element in operable
communication with the resilient stress inducer to one of compress
or tension the resilient stress inducer.
17. The method of generating power in a wellbore of claim 16
wherein the method comprising releasing the another magnetic
element and allowing the magnetic element to oscillate on the
resilient stress inducer to induce the stress on the piezoelectric
component.
18. A downhole power generation arrangement comprising: a housing;
at least one first magnetic element disposed within the housing and
axially oscillatorily movable within the housing; a first resilient
stress inducer and a second resilient stress inducer axially
aligned with the at least one magnetic element, the first resilient
stress inducer extending in one direction from the at least one
magnetic element and the second resilient stress inducer extending
in an axially opposite direction from the at least one magnetic
element; at least one piezoelectric component disposed in contact
with one of the first and second resilient stress inducers; and an
axially oscillatorily movable component in operable communication
with the housing, the component including at least one second
magnetic element thereat having an attractive polarity relative to
the at least one first magnetic element.
Description
BACKGROUND
[0001] For nearly a century, pump jacks have been used in the
production of hydrocarbons from downhole formations. Such jacks are
seen atop many oil fields, their rhythmic movements common. It is
well known how the pump jacks work, which is by moving sucker rods
up and down within the wellbore. For the same near century, the
pumps have worked very well doing precisely that, pumping.
[0002] More modern well systems while still employing pump jacks
also are instrumented extensively downhole. This requires
substantial amounts of available power in the downhole environment.
Power is for the most part delivered from the surface but due to
the small amount of available space in the hole, allocation of such
space is a source of trepidation. Since the hydrocarbon recovery
art is always in search of improved means to produce hydrocarbons,
any reduction in components needed within the cross-section of the
wellbore would be well received.
SUMMARY
[0003] A power generation system includes a piezoelectric
component, a resilient stress inducer in operable communication
with the piezoelectric component, and an actuator in operable
communication with the resilient stress inducer to energize and
release the resilient stress inducer.
[0004] A method for generating power in a wellbore includes moving
an actuator, inducing an oscillating stress on a piezoelectric
component with the actuator, and generating a voltage with the
piezoelectric component in response to the induced stress on the
piezoelectric component.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Referring now to the drawings wherein like elements are
numbered alike in the several Figures:
[0006] FIG. 1 is a schematic view of a pump jack;
[0007] FIGS. 2-6 are each schematic views of a piezoelectric power
generation arrangement utilizing the pump jacks in different
positions.
DETAILED DESCRIPTION
[0008] In order to enhance understanding of the invention
applicants have elected to describe briefly the components of the
tool followed by a discussion of its operation.
[0009] Referring to FIG. 1, a pump jack 10 is illustrated
schematically. One of skill in the art will recognize a walking
beam 12 and sucker rod 14 extending into a wellbore 16. The pump
jack 10 as is known, reciprocates the sucker rod up and down in the
wellbore. The sucker rod 14 of the pump jack is the only portion of
the pump jack that is modified in connection with the invention and
therefore other components of the pump jack need not be described
in detail. Also to be noted is that although a pump jack is
utilized herein as a source of movement, other sources of similar
movement could be substituted while maintaining the benefits of the
inventive concept.
[0010] Referring to FIG. 2, a power generation arrangement 20 for
use in combination with a reciprocating source such as a pump jack
is illustrated. The arrangement includes a housing 22, within which
is disposed at least one piezoelectric component 24 which may be a
single piezoelectric element or a plurality of elements in a stack.
The component 24 is in physical force transmission contact with a
resilient member (stress inducer) 26, illustrated as a coil spring,
but could be any device similarly capable of oscillatory movement.
Spring 26 is in operable communication with a magnetic element 28,
which may be a rare earth magnet or may simply be a ferrous
element. The magnetic element 28 is also in operable communication
with another resilient member 30 (also illustrated as a coil spring
for convenience but as noted for spring 26, other devices capable
of oscillatory movement are equally applicable). Spring 30 may be
the same or different from spring 26, providing that the desired
oscillatory motion of magnetic element 28 and associated mechanical
compression of component 24 is preserved. Spring 30 is bounded by a
compression cap 32 in the illustrated embodiment but could
alternatively be bounded by another piezoelectric component (not
shown) that essentially would be a mirror image of the component
24. In such an arrangement, power generation would occur based upon
movement of the magnetic element 28 in both axial directions.
[0011] Through an inside dimension of all of the foregoing
components is at least one sucker rod 14 or sucker rod extension 34
having at least one magnetic element 36 disposed thereat. Magnetic
element 36 may be a magnet or simply a ferrous element providing
that either it or the magnetic element 28 is in fact a magnet. At
least one of the two magnetic elements 28 and 36 must provide a
magnetic field for operability of the invention. It is to be noted
that the sucker rod 34 is used in an exemplary manner and is not a
limitation of the invention. Any support for the magnetic element
36 that is an oscillatory structure itself is substitutable.
Magnetic element 36, if indeed a magnet, is to be attractively
polarized relative to magnetic element 28 such that a strong
attractive force is generated between the magnetic elements.
Further noted is that at portions of the sucker rod 34 other than
at the at least one magnetic element 36, there is disposed a
non-magnetic sleeve 38. Sleeve 38 that functions to align the
magnetic elements and the sucker rod to ensure that they remain
non-contacting in nature thereby reducing frictional losses
otherwise caused by magnetic attraction of the magnetic element 28
to the sucker rod 34, which is usually a metal, or actual contact
between magnetic elements 28 and 36.
[0012] As one of skill in the art should recognize the sucker rod
34 moves up and down pursuant to the motion of the walking beam
pictured in FIG. 1. This movement is harnessed as taught herein not
only for its original purpose of pumping stubborn well fluids to
the surface but to generate power for downhole devices as well.
[0013] Referring to FIGS. 2-6 as a sequence of drawings showing the
device in different positions, the operation thereof will become
clearer. As magnetic element 36 draws nearer magnetic element 28
the attractive magnetic fields they exhibit (or one field
attracting the ferrous element of the other) begin to draw magnetic
element 28 toward magnetic element 36, to some extent overcoming
spring 26 in compression and spring 30 in tension. This movement of
magnetic element 28 will impart a compressive load, through spring
26 to component 24 thereby creating an electrical potential in
component 24. Since the magnetic element 36 is moving towards
magnetic element 28, it should be understood that the magnitude of
the compressive load on the component 24 for this movement is small
and consequently the potential generated is small. As the sucker
rod continues, its movement uphole and as illustrated in FIG. 3,
the magnetic elements 28 and 36 align and thereby are at the
highest attractive force therebetween. Yet farther uphole movement
of sucker rod 34 draws magnetic element 28 to compress spring 30
while extending spring 28. This continues, since the magnetic
elements are engineered to have a greater attractive force to each
other than the springs 26 and 30 have spring force to separate
them, until the spring 30 is substantially maximally compressed.
After such compression, illustrated in FIG. 4, magnetic element 36
is moved farther uphole with sucker rod 34 thereby misaligning the
magnetic elements and thus reducing the attractive forces
therebetween. At a point, the attractive force between magnetic
element 28 and magnetic element 36 is overcome by the spring force
of springs 30 and 26. As this occurs, springs 30 and 26 propel
magnetic element 28 back toward component 24 as illustrated in FIG.
6. This motion, as one of skill in the art should appreciate,
presents a relatively large compressive load on the component 24
thereby generating a large electrical potential. Further, because
of the springs of 30 and 26, the magnetic element 28 will oscillate
causing a number of compressions on the component 24, each
developing an electrical potential. Since the oscillations diminish
in magnitude with each cycle, the compressive load is also reduced
but some of the benefit is still achieved by oscillatory motion
until magnetic element 28 is magnetically "bound" again to magnetic
element 36 (or another similar magnetic element if the sucker rod
stroke is long enough to create multiple actuations due to magnetic
interaction using multiple magnetic elements 36). A capacitor 40 is
electrically connected to the piezoelectric component 24 to store
the potential generated by the disclosed system for use when
needed.
[0014] As was noted hereinabove, a pump jack is but one source of
movement for a system such as that disclosed. Further, and also as
noted, in an alternative embodiment, compression cap 32 could be
substituted by an additional piezoelectric component so that
oscillatory compressive loading on both springs 30 and 26 will
produce potentials. This will increase available power downhole
from the system as described. In addition hereto, rapid unloading
of the component 24 will create a voltage as well. This voltage may
be made usable by employing a rectifier bridge 42 in the electrical
circuit connected to the component 24.
[0015] While preferred embodiments have been shown and described,
modifications and substitutions may be made thereto without
departing from the spirit and scope of the invention. Accordingly,
it is to be understood that the present invention has been
described by way of illustrations and not limitation.
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