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WO2014100267A1 - Procédé et dispositif de récupération d'énergie en fond de trou - Google Patents

Procédé et dispositif de récupération d'énergie en fond de trou Download PDF

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Publication number
WO2014100267A1
WO2014100267A1 PCT/US2013/076276 US2013076276W WO2014100267A1 WO 2014100267 A1 WO2014100267 A1 WO 2014100267A1 US 2013076276 W US2013076276 W US 2013076276W WO 2014100267 A1 WO2014100267 A1 WO 2014100267A1
Authority
WO
WIPO (PCT)
Prior art keywords
magnetostrictive element
rotor
magnetostrictive
coil
response
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2013/076276
Other languages
English (en)
Inventor
Zachary Murphree
Balakrishnan Nair
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Oscilla Power Inc
Original Assignee
Oscilla Power Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US13/936,074 external-priority patent/US9634233B2/en
Application filed by Oscilla Power Inc filed Critical Oscilla Power Inc
Publication of WO2014100267A1 publication Critical patent/WO2014100267A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B41/00—Equipment or details not covered by groups E21B15/00 - E21B40/00
    • E21B41/0085—Adaptations of electric power generating means for use in boreholes
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02N—ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR
    • H02N2/00—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction
    • H02N2/18—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction producing electrical output from mechanical input, e.g. generators
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N35/00—Magnetostrictive devices
    • H10N35/101—Magnetostrictive devices with mechanical input and electrical output, e.g. generators, sensors

Definitions

  • the apparatus is a device to generate electrical energy from mechanical motion in a downhole environment.
  • An embodiment of the device includes a magnetostrictive element and an electrically conductive coil.
  • the magnetostrictive element has a first end and a second end. The first and second ends are coupled between two connectors.
  • the magnetostrictive element is configured to experience axial strain in response to radial movement of at least one of the connectors relative to the other connector.
  • the electrically conductive coil is disposed in proximity to the magnetostrictive element. The coil is configured to generate an electrical current in response to a change in flux density of the magnetostrictive element.
  • Other embodiments of the apparatus are also described.
  • FIG. 1 depicts a cutaway view of a schematic diagram of one embodiment of a downhole energy harvester system with an axially-loaded magnetostrictive energy harvester that may be driven by a downhole tool.
  • Fig. 2 depicts a cross-sectional view of the magnetostrictive energy harvester of Fig. 1.
  • Fig. 3 depicts a cross-sectional view of another embodiment of a
  • magnetostrictive energy harvester having a separate magnetostrictive material for the return flux path.
  • FIG. 4 depicts a cutaway view of a schematic diagram of one embodiment of a pressure vessel with a compression fixture to impose compression on a magnetostrictive energy harvester.
  • Fig. 6 depicts one embodiment of a rotor shown inside a stator, along with the hypocycloid path that the tips of each lobe of the rotor follow.
  • Figs. 7A-C depict one embodiment of the motion of the rotor inside the stator.
  • FIGs. 8A-C depict one embodiment of locations of the harvester for
  • FIG. 9 depicts one embodiment of a harvester disposed between the rotor of the mud motor and the drill bit shaft.
  • Fig. 10 depicts an embodiment with multiple individual PTOs deployed around the flex shaft.
  • FIG. 11 depicts a close-up of a one embodiment of an interface configuration between the rotor and the harvester.
  • Fig 12 depicts a graph illustrating shell thickness as a function of core diameter.
  • Fig. 13 depicts a graph illustrating power output as a function of core diameter for different device lengths.
  • Fig. 14 depicts a graph illustrating a safety factor for buckling of a device.
  • magnetostrictive elements caused by the eccentric motion of one end of a device relative to the other.
  • eccentric motion occurs in mud motor assemblies that drive drill bits in downhole drilling operations.
  • the rotor of the mud motor moves in an eccentric fashion inside a stator, as will be described below in greater detail.
  • a device uses the radial motion of the eccentric center-point of the rotor of a mud motor to displace the tip of a magnetostrictive device that is hinged at both ends.
  • One of these hinged ends is connected to the center of the rotor, and the other is connected to a rigid point above the mud motor.
  • the other end may be connected to a shaft that is mechanically coupled to a drill bit. This allows the device to operate in an axial-loading configuration rather than a flexing or bending configuration.
  • Fig. 1 depicts a cutaway view of a schematic diagram of one embodiment of a downhole energy harvester system 100 with an axially-loaded magnetostrictive energy harvester 110 that may be connected to and/or driven by a downhole tool such as a mud motor.
  • An embodiment of the device may be disposed within the annulus of a drill string 102, in which case one end is connected to a fixed, hinged connector 118 (or other flexible connector) at the mud motor, and the other end is connected to a mobile, hinged end 120 at the rotor.
  • the end connected to the hinged end 120 may be connected to the center of the rotor or to another offset location on the rotor. This may limit the outer diameter of the device to a dimension that still allows drilling mud to pass around the device.
  • the location of the device is selected or designed so that the device is sealed from the mud.
  • the depicted magnetostrictive energy harvester 110 includes a magnetostrictive rod 112, an electrically conductive coil 114 disposed around the rod 112, and a return path 116 outside of the coil 114.
  • the magnetostrictive rod 112 may be any shape and/or size. Although some embodiments described herein have a circular cross-section, other embodiments may have other canonical or non-canonical cross-sectional shapes.
  • the electrically conductive coil 114 may be any type of conductive material. Additionally, the coil 114 may be any length, diameter, or cross-sectional shape.
  • the return path 116 may be made of mild steel or some other ferrous material.
  • Fig. 2 depicts a cross-sectional view of the magnetostrictive energy harvester 110 of Fig. 1.
  • the harvester 110 has a circular cross-section in the plane normal to the axis of the drill string 102.
  • this embodiment may have the magnetostrictive rod 112 at the center of the arrangement, with the coil 114 surrounding the rod 112, and the return flux -path 116 on the outside of the coil 114.
  • FIG. 3 depicts a cross-sectional view of another embodiment of a
  • magnetostrictive energy harvester having a separate magnetostrictive material 120 for the return flux path.
  • a separate coil 122 is wrapped around the second magnetostrictive material 120.
  • the outer rod is split such that its cross-section resembles an annulus with an arc of material missing, i.e., it not a complete circular path.
  • the second coil 122 is wrapped around this second magnetostrictive rod 120 in a manner that does not also include wrapping around the inner coil 114 and inner
  • the cross-section of the out rod 120 is in the shape of a "C" and the coil is wrapped around the C-shaped rod.
  • the combined elements include a central magnetostrictive rod 112 and coil 114, and an outer C-shaped rod 120 and coil 122.
  • Fig. 4 depicts a cutaway view of a schematic diagram of one embodiment 130 of a pressure vessel 134 with a compression fixture 132 to impose compression on a magnetostrictive energy harvester.
  • One embodiment of the pressure vessel 130 includes a compression 132 fixture that maintains the magnetostrictive elements in compression throughout the entire operating motion.
  • the downhole tool may be a mud-motor that imposes an eccentric motion on the tip of the power generation device, causing an axial deflection of the magnetostrictive rod.
  • the hinge point at the upper end of the device has an important effect on the operation of the device. If the hinge point is located directly above the center of the circle of eccentricity of the rotor (which would coincide with the center of the BHA or drill-pipe, in most cases), then the frequency of the loading of the rod becomes twice the frequency of the eccentric rotation of the rotor. As an example, a mud motor with 4 lobes that has a motor rotary speed of 120 cycles per minute (2 Hz) would rotate around its circle of eccentricity at a frequency of 8 Hz. The center- mounted upper hinge configuration would go through two complete loading cycles for each of these rotations, for a total loading frequency of 16 Hz. Some embodiments of this design might require that the motion of the tip attached to the mud motor be constrained to a linear path, which could affect its overall efficiency and cost/ease of implementation.
  • the upper hinge point can be located off-center, which provides for a larger total deflection at the cost of operating at half the frequency of the center- mounted hinge point.
  • This configuration has the potential benefit of not requiring the tip to be constrained to a linear translational motion, and can instead operate with the tip moving in the circular path that follows the circle of eccentricity of the rotor.
  • At least one permanent magnet is located within or disposed relative to the return path 116.
  • Some embodiments of the proposed device generate electrical power through strain changes in one or more magnetostrictive elements 112 caused by the eccentric motion of one end (see 120) of the device relative to the other end (see 118).
  • One common application where such motion occurs and where power generation is needed is in the mud motor assembly that drives the drill bit in downhole drilling operations.
  • the rotor of the mud motor moves in an eccentric fashion inside the stator.
  • the rotor has at least one less lobe than the stator has cavities, and the rotor traces out a path that can be described as a hypocycloid. This geometry occurs when a fixed point on the perimeter of a circle is traced while the circle rolls within a larger circle.
  • the number of cusps on a hypocycloid is determined by the ratio of radii of these two circles (k). When the ratio is a whole number, the hypocycloid will be a closed shape.
  • the path of the rotor can be described by a hypocycloid with a ratio k, and the shape of the rotor will then be that of the hypocycloid with a ratio of k- 1.
  • the central circle 146 is the circle of eccentricity, which is the locus of points of the center of the rotor as it moves eccentrically within the stator.
  • rotor and stator do not necessarily have the sharp cusps of the hypocycloids 142 and 144. Instead, the rotor and/or stator may have rounded edges.
  • Fig. 6 depicts one embodiment of a rotor 152 shown inside a stator 154, along with the hypocycloid path 156 that the tips of each lobe of the rotor follow.
  • the hypocycloid 156 that the rotor follows as it rotates is included for clarity.
  • the hypocycloids will be used as their parametric equations are more easily manipulated than that of the actual rotor.
  • the specifics of the rotor/stator geometry are often different between various manufacturers, the underlying principle, which is represented clearly by the hypocycloids, is unchanging.
  • Figs. 7A-C depict one embodiment of the motion of the rotor 152 inside the stator 154.
  • the rotor 152 moves inside the stator 154, it is rotating in a clockwise direction while also precessing counterclockwise about the circle of eccentricity.
  • the cusp of the rotor hypocycloid that is initially at (1.5, 0) moves into the fourth quadrant in Fig. 7B, and eventually mates with the fourth quadrant cusp of larger stator hypocycloid in Fig. 7C
  • the outer circle 162 is termed the apocentric circle to represent the farthest excursion of the rotor cusp from the axis of the stator 154, which is coincident with the origin.
  • the intermediate circle 164 is termed the pericentric circle to represent the closest that the rotor cusp gets to the stator axis. This distance is further illustrated by thick black line that is drawn between the pericentric circle and the rotor cusp in each frame.
  • the device may be disposed at the upper end of the mud motor (the end farthest from the drill bit).
  • the rotor end of the device would be pinned on or very near one of the lobes of the rotor, and the other end would be pinned to a bearing assembly, located above the mud motor, that is allowed to rotate at the same speed as the rotor, albeit in a non-eccentric fashion, about the same axis as the mud motor.
  • the pinning location on the bearing assembly would be located some distance from the axis of rotation.
  • a device connected between the rotor and bearing assembly would experience a change in length caused by the rotor end of the device moving closer to and farther from the axis of the borehole as the assembly rotates because the bearing assembly and the rotor are synchronously rotating around the axis of the borehole,.
  • the distance between the pericenter and apocenter, which is equivalent to the diameter of the eccentric circle, and the particular geometry of the assembly would determine the axial strain applied to the device.
  • This strain is applied to the magnetostrictive component, corresponding changes in the magnetic properties of the material result.
  • This change in magnetic properties when coupled with an external flux path and a bias magnetic field, will produce changes in the magnetic flux through the magnetostrictive, which can then be converted into electrical power through conventional induction with a coil surrounding some portion of the flux path.
  • FIGs. 8A-C depict one embodiment of locations of the harvester for
  • Fig. 8A the harvester 110 is at its longest (apocenter). If this position is taken to be the location of minimum axial strain in the device, then Fig. 8B shows the harvester 110 at pericenter, which corresponds to the maximum strain position. Fig. 8C shows the device at the apocenter, again, although at a different point as the top end of the device rotates counter-clockwise at the rotor side of the assembly.
  • Fig. 9 depicts one embodiment of a harvester disposed between the rotor of the mud motor and the drill bit shaft.
  • the rotor 152 is connected to the drill bit with a flex shaft (not shown). This shaft accommodates the eccentricity of the rotor 152 while also transferring the torque produced by the mud motor to the drill bit.
  • the rotor end of the flex shaft is rigidly connected to and concentric with the rotor 152, and the drill bit end is located in the center of the bore axis (concentric with the stator 154) by a set of bearings.
  • the rotor end of the device is pinned on or very near one of the lobes of the rotor 152, and the other end is pinned at or near the flex shaft, or at some fixture that is either coupled to or rotates with the flex shaft.
  • the radial offset is essentially the flex shaft. Since the flex shaft and the rotor 152 are synchronously rotating around the axis of the borehole, a harvester connected between the rotor 152 and the drill bit shaft, as described above, would experience a change in length caused by the rotor end of the device moving closer to and farther from the axis of the borehole as the assembly rotates. The distance between the pericenter and apocenter, which is equivalent to the diameter of the eccentric circle, and the particular geometry of the assembly would determine the axial strain applied to the harvester.
  • a magnetostrictive element is disposed between the rotor 152 and the drill bit shaft. Strain is applied to the magnetostrictive element 112 as one end of the magnetostrictive element 112 moves closer to and farther from the axis of the borehole as the assembly rotates. This strain results in corresponding changes in the magnetic properties of the magnetostrictive material 112. These changes in magnetic properties, when coupled with an external flux path 116 and a bias magnetic field (e.g., from one or more permanent magnets 136), will produce changes in the magnetic flux through the magnetostrictive element 112, which can then be converted into electrical power through induction with the coil 114 surrounding some portion of the flux path.
  • a bias magnetic field e.g., from one or more permanent magnets 136
  • Fig. 10 depicts an embodiment with multiple individual harvesters 110 deployed around the flex shaft. This allows multiple magnetostrictive rod/flux path assemblies to be disposed between the rotor 152 and the drill bit shaft. Also shown is one of the individual magnetostrictive power take-off (PTO) units.
  • PTO power take-off
  • Fig. 11 depicts a close-up of a one embodiment of an interface configuration between the rotor and the harvester.
  • one or more magnetostrictive rods or elements may be able to generate over 1 Watt of power. In further embodiments, one or more rods may be able to generate more than 10 Watts of power.
  • the first way is to decrease the length between the two pinning points (e.g., the rotor and the bearing). Because the two pinning points (e.g., the rotor and the bearing). Because the two pinning points (e.g., the rotor and the bearing). Because the two pinning points (e.g., the rotor and the bearing). Because the two pinning points (e.g., the rotor and the bearing). Because the two pinning points (e.g., the rotor and the bearing).
  • the compression/extension of the device is determined by the eccentricity of the rotor motion, a shorter magnetostrictive will have higher strain, which equates to a higher stress in the element (Table 1).
  • the second way to increase the stress in the rod is to alter the pinning locations of each end of the device. The main objective in doing this is to increase the angle of the device from horizontal, which results in a larger component of the deflection caused by the eccentric motion to be along the axis of the magnetostrictive element.
  • the magnetostrictive would be normal to the axis of the borehole, which would result in all of the deflection caused by the eccentricity to be along the axis of the
  • the pinned end at the rotor may be located as far away from the rotor axis as possible, and the pinned end at the bearing assembly is as close to the bearing's axis of rotation.
  • Another method to increase the power output of the device is to increase the diameter of the magnetostrictive core.
  • the allotted volume contains the magnetostrictive core, a coil of electrically conductive material, and a return flux path, as described above.
  • all of these components are concentric, with the magnetostrictive as the innermost cylinder, surrounded by a coil of wire, and all enclosed in an annular return flux path.
  • This configuration also may have magnetically permeable flux path elements on the top and bottom to magnetically connect the
  • the return flux path is sized appropriately in order to prevent saturation of this component.
  • magnetostrictive and flux path material equal to 1.4 and 1.7 T, respectively.
  • Fig. 12 One example of a graph illustrating this optimization is seen in Fig. 12.
  • An optimization of the core diameter for power production indicates, in one example, that the largest possible core may be used while still allowing for a coil with 2-4 layers of wire, independent of wire gauge. This assumes that inductive effects can be fully compensated, which will be a function of the frequency at which the device is expected to operate.
  • An example of this optimization is shown in Figure 13. For a given device length, the power output increases exponentially with the diameter of the core, up to a point where the coil becomes too small. The power numbers shown here are representative. This figure also shows how the power output increases with the device length.
  • Fig. 14 shows the buckling safety factor as a function of core diameter.
  • the buckling safety factor is the critical buckling stress divided by the actual applied stress.
  • Fig. 14 illustrates that even for the worst case scenario, a device as described herein may have an acceptable safety factor for core diameters greater than 0.75".

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  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Geology (AREA)
  • Mining & Mineral Resources (AREA)
  • Physics & Mathematics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Earth Drilling (AREA)

Abstract

La présente invention concerne un dispositif générant de l'énergie électrique à partir d'un mouvement mécanique dans un environnement de fond de trou. Le dispositif comprend un élément magnétostrictif et une bobine électroconductrice. L'élément magnétostrictif présente une première extrémité et une seconde extrémité. Les première et seconde extrémités sont accouplées entre un rotor et un palier. L'élément magnétostrictif est configuré pour subir une déformation axiale en réponse au mouvement radial du rotor et/ou du palier par rapport à l'autre. La bobine électroconductrice est disposée à proximité de l'élément magnétostrictif. La bobine est configurée pour générer un courant électrique en réponse à une modification de la densité de flux de l'élément magnétostrictif.
PCT/US2013/076276 2012-12-18 2013-12-18 Procédé et dispositif de récupération d'énergie en fond de trou Ceased WO2014100267A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US201261738757P 2012-12-18 2012-12-18
US61/738,757 2012-12-18
US13/936,074 US9634233B2 (en) 2012-07-05 2013-07-05 Axial loading for magnetostrictive power generation
US13/936,074 2013-07-05

Publications (1)

Publication Number Publication Date
WO2014100267A1 true WO2014100267A1 (fr) 2014-06-26

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017184124A1 (fr) * 2016-04-19 2017-10-26 Halliburton Energy Services, Inc. Dispositif de collecte d'énergie de fond

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5439359A (en) * 1991-10-23 1995-08-08 Leroy; Andre Rotary positive displacement machine with helicoid surfaces of particular shapes
US5615172A (en) * 1996-04-22 1997-03-25 Kotlyar; Oleg M. Autonomous data transmission apparatus
US20050001704A1 (en) * 2000-10-03 2005-01-06 Teruo Maruyama Electromagnetostrictive actuator
US20120056432A1 (en) * 2010-02-01 2012-03-08 Oscilla Power Inc. Wave energy harvester with improved performance
US20120228875A1 (en) * 2011-03-10 2012-09-13 Hardin Jr John R Systems and methods of harvesting energy in a wellbore

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5439359A (en) * 1991-10-23 1995-08-08 Leroy; Andre Rotary positive displacement machine with helicoid surfaces of particular shapes
US5615172A (en) * 1996-04-22 1997-03-25 Kotlyar; Oleg M. Autonomous data transmission apparatus
US20050001704A1 (en) * 2000-10-03 2005-01-06 Teruo Maruyama Electromagnetostrictive actuator
US20120056432A1 (en) * 2010-02-01 2012-03-08 Oscilla Power Inc. Wave energy harvester with improved performance
US20120228875A1 (en) * 2011-03-10 2012-09-13 Hardin Jr John R Systems and methods of harvesting energy in a wellbore

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017184124A1 (fr) * 2016-04-19 2017-10-26 Halliburton Energy Services, Inc. Dispositif de collecte d'énergie de fond
US10246973B2 (en) 2016-04-19 2019-04-02 Halliburton Energy Services, Inc. Downhole energy harvesting device

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