Piezoelectric resonant power generator
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.
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.
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.
SUMMARYA 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.
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.
Referring now to the drawings wherein like elements are numbered alike in the several Figures:
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.
Referring to
Referring to
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.
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
Referring to
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.
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.
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.
Type: Application
Filed: Mar 27, 2007
Publication Date: Oct 2, 2008
Inventors: Jason J. Barnard (Katy, TX), Robert S. O'Brien (Katy, TX)
Application Number: 11/728,760
International Classification: H02N 2/18 (20060101); H01L 41/113 (20060101);