Patent Publication Number: US-2017356274-A1

Title: Systems And Methods For Multi-Zone Power And Communications

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. §119 to U.S. Provisional Patent Application Ser. No. 62/349,769, titled “Systems and Methods For Multi-Zone Power and Communications” and filed on Jun. 14, 2016, the entire contents of which are hereby incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present application relates generally to power and data transmission in a multi-zone completion environment using unique magnetic coupling technology. 
     BACKGROUND 
     In resource recovery, it may be useful to supply electrical power and monitor various conditions at locations in a wellbore (also called herein a “borehole”) remote from an observer. In particular, it may be useful in completions and production operations to provide power and monitor temperature, pressure, fluid velocity or flowrate, and/or fluid characteristics within isolated zones between packer elements in a wellbore. However, it can be difficult or inconvenient to deliver power in such environments. In some cases, electrical cables are installed in the wellbore extending across each zone, but such cables sometimes are difficult and expensive to install and maintain in an operationally secure manner. In addition, it can be difficult to install a cable in the confined space of an isolated zone. Additionally, such cables may become eroded or damaged during installation or during use. Such damage may require costly workovers and delays in oil and gas production. 
     Wireless transmission of power and data has also not been an option for transmitting into isolated zones between the packer elements in a wellbore. Packer elements generally include sealing glands and metallic slips to seal the packer element in position in the annulus and to isolate zones within a wellbore. The metallic components of the packer elements would short out any electrical or signal path from the surface to the casing upon setting however, and thus current and signal cannot flow wirelessly from the surface, past the packer elements, and down the casing. 
     Because such boreholes may extend several miles, eliminating some of the wires associated with power and sensor technology becomes desirable since it is not always practical to replace power sources or cables used in conventional boreholes. 
     SUMMARY 
     In general, in one aspect, the disclosure relates to a packer assembly for disposal within a subterranean wellbore lined by a casing. The packer assembly can include a packer having an upper end, a lower end, and a feedthrough that traverses the packer from the upper end to the lower end, where the upper end is configured to couple to a first tubing string, where the lower end is configured to couple to a second tubing string. The packer assembly can also include a first core disposed around the second tubing string adjacent to the lower end of the packer. The packer assembly can further include an electrical wire disposed within the feedthrough of the packer, where the electrical wire has a proximal end and a distal end wrapped around the first core. The proximal end of the electrical wire can be configured to receive a first power from a power source disposed above the upper end of the packer, where the distal end of the electrical wire is configured to use the first power to induce a second power in the first core, where the second power in the first core generates a first current that flows on the second tubing string away from the first core. 
     In another aspect, the disclosure can generally relate to a power transmission system for use within in a subterranean wellbore having a casing disposed against a subterranean formation and defining an outer perimeter of the subterranean wellbore and forming a cavity. The system can include a power source disposed proximate to a surface at an opening of the subterranean wellbore, where the power source generates a first power. The system can also include a first tubing string segment disposed within the cavity. The system can further include a first packer mechanically coupled to a first distal end of the first tubing string within the cavity of the subterranean wellbore, where the first packer has a first feedthrough disposed therein along a first height of the first packer. The system can also include a second tubing string segment mechanically coupled to a first bottom end of the first packer within the cavity of the subterranean wellbore. The system can further include a first core disposed around the second tubing string segment adjacent to the bottom end of the first packer and the first feedthrough. The system can also include a first electrical wire disposed within the first feedthrough of the first packer, where the first electrical wire has a first end coupled to the power source and a second end wrapped around the first core, wherein the first electrical wire receives the first power from the power source. The first power flowing through the first electrical wire disposed around the first core can induce a second power in the first core, where the second power in the first core generates a first current that flows on the second tubing string away from the first core further into the subterranean wellbore. 
     These and other aspects, objects, features, and embodiments will be apparent from the following description and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings illustrate only example embodiments of systems and devices for transmitting power and data to isolated zones in a subterranean wellbore and are therefore not to be considered limiting of its scope, as transmitting power and data to isolated zones within a wellbore may admit to other equally effective embodiments. The elements and features shown in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the example embodiments. Additionally, certain dimensions or positionings may be exaggerated to help visually convey such principles. In the drawings, reference numerals designate like or corresponding, but not necessarily identical, elements. 
         FIG. 1  is a schematic diagram of a field system having wireless power and data transmission capabilities within zones in a subterranean wellbore, according to an example embodiment. 
         FIGS. 2A-2C  show a circuit diagram and two schematic diagrams, respectively, that includes a core according to an example embodiment. 
         FIG. 3  is a current flow schematic at a downhole packer assembly, according to an example embodiment. 
         FIG. 4  is an illustration showing how magnetic coupling works in a cased well construct, according to an example embodiment. 
         FIG. 5  is a cross-sectional schematic showing a magnetic field generated by current sheets that surround a magnetic toroidal core, according to an example embodiment. 
         FIG. 6  is a close-up schematic of a midstream portion of an isolated zone, showing another case of current sheets on tubing and inside of a casing wall, according to an example embodiment. 
         FIG. 7  is a close-up schematic of a midstream portion of an isolated zone, having a sensor system placed along a cell or zone region along tubing, according to an example embodiment. 
         FIG. 8  is a schematic diagram of a three-zone field system, broken up to fit the page, according to an example embodiment. 
         FIG. 9A  is a schematic of a packer assembly with embedded inductive coupling and sensors, in an unset position, according to an example embodiment. 
         FIG. 9B  is a schematic of the packer assembly of  FIG. 9A , in set position, according to an example embodiment. 
         FIG. 10  is a schematic of a single zone simulator for laboratory testing purposes, according to an example embodiment. 
         FIG. 11  is a schematic of a dual-zone simulator for laboratory testing purposes, according to an example embodiment. 
     
    
    
     DESCRIPTION OF EXAMPLE EMBODIMENTS 
     Example embodiments directed to methods, systems, and devices for inductively coupled power and data transmission to isolated zones in a subterranean wellbore will now be described with reference to the accompanying figures. Like, but not necessarily the same or identical, elements in the various figures are denoted by like reference numerals for consistency. In the following description of the example embodiments, numerous specific details are set forth in order to provide a more thorough understanding of the disclosure herein. However, it will be apparent to one of ordinary skill in the art that the example embodiments herein may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description. 
     A user as described herein may be any person that is involved with a piping system in a subterranean wellbore and/or transmitting power and data within the subterranean wellbore for a field system. Examples of a user may include, but are not limited to, a roughneck, a company representative, a drilling engineer, a tool pusher, a service hand, a field engineer, an electrician, a mechanic, an operator, a consultant, a contractor, and a manufacturer&#39;s representative. 
     If a component of a figure is described but not expressly shown or labeled in that figure, the label used for a corresponding component in another figure can be inferred to that component. Conversely, if a component in a figure is labeled but not described, the description for such component can be substantially the same as the description for the corresponding component in another figure. The numbering scheme for the various components in the figures herein is such that each component is a three or four digit number and corresponding components in other figures have the identical last two digits. 
     In the foregoing figures showing example embodiments of wireless power and data transmission systems, one or more of the components shown may be omitted, repeated, and/or substituted. Accordingly, example embodiments of wireless power and data transmission systems should not be considered limited to the specific arrangements of components shown in any of the figures. Further, any description of a figure or embodiment made herein stating that one or more components are not included in the figure or embodiment does not mean that such one or more components could not be included in the figure or embodiment, and that for the purposes of the claims set forth herein, such one or more components can be included in one or more claims directed to such figure or embodiment. 
     Terms such as “first”, “second”, “primary”, “secondary”, “top”, “bottom”, “side”, “width”, “length”, “upper”, “lower”, “above”, “below”, “inner”, and “outer” are used merely to distinguish one component (or part of a component or state of a component) from another. Such terms are not meant to denote a preference or a particular orientation, and are not meant to limit embodiments of wireless power and data transmission systems described herein. 
       FIG. 1  shows a schematic diagram of a field system  100  that can transmit power and data in a subterranean wellbore  102  during completions and/or production operations in accordance with one or more example embodiments. Referring now to  FIG. 1 , the field system  100  in this example includes a completed wellbore  102  within a subterranean formation  104  below a ground surface  108 . The point where the wellbore  102  begins at the surface  108  can be called the entry point. The subterranean formation  104  can include one or more of a number of formation types, including but not limited to shale, limestone, sandstone, clay, sand, and salt. In certain embodiments, a subterranean formation  104  can also include one or more reservoirs in which one or more resources (e.g., oil, gas, water, steam) can be located. One or more of a number of field operations (e.g., drilling, setting casing, extracting downhole resources) can be performed to reach an objective of a user with respect to the subterranean formation  104 . 
     The wellbore  102  can have one or more of a number of segments, where each segment can have one or more of a number of dimensions. Examples of such dimensions can include, but are not limited to, size (e.g., diameter) of the wellbore  102 , a curvature of the wellbore  102 , a total vertical depth of the wellbore  102 , a measured depth of the wellbore  102 , and a horizontal displacement of the wellbore  102 . Surface equipment  114  can be used to create and/or develop (e.g., extract downhole materials) the wellbore  102 . The surface equipment  114  can be positioned and/or assembled at the surface  108 . The surface equipment  114  can include, but is not limited to, a power source  195  and other equipment for multi-zone completions, where the zones  120  are defined below. 
     Included in the field system  100  of  FIG. 1  is an example power delivery system  190 . A completed wellbore  102  can include a casing string  109  that defines the outer perimeter of the wellbore  102  and a production tubing  110  disposed within the cavity  188  (also called an annular volume herein) formed by the casing string  109 . Extracted downhole materials can flow through the production tubing  110  towards the surface equipment  114 . The casing string  109  and the production tubing  110  are generally electrically conductive. The wellbore  102  can include a number of perforated zones  120  isolated from one another via isolation packer elements  124   a ,  124   b , . . .  124   n  (referred to collectively herein as isolation packer elements  124 , where n refers to the packer closest to the toe or distal end of the wellbore  102 ). Each packer element  124  is disposed within the cavity  188  between the tubing  110  and the casing string  109 . A zone  120  can be part of one or more segments of the wellbore  102 . In addition, or in the alternative, a segment of the wellbore  102  can include one or more zones  120 . 
     In this example, an electric line or cable  126  extends from a system power source  195  above the surface  188  to a production packer element  128 . The packer element  128  is also disposed within the cavity  188  between the tubing  110  and the casing string  109 . In certain example embodiments, the production packer element  128  and the isolation packer elements  124  are feedthrough packers. In other words, the production packer element  128  and the isolation packer elements  124  can include feedthrough, channel, or other pathway to allow a component (e.g., an electrical cable or electrical conductors) of an example wireless power and data transmission system to pass therethrough. In this case, the production packer element  128  has feedthrough  125 , and each of the isolation packer elements  124  (with the exception of isolation packer element  124   n ) has feedthrough  126 . 
     Generally, in certain example embodiments, the production packer element  128 , by virtue of the cable  126  disposed in the feedthrough  125 , is in electrical communication with a first magnetic toroidal core  130 , and the first magnetic toroidal core  130  in turn transmits currents wirelessly via the electrically-conductive production tubing  110  to an upper magnetic toroidal core  132   a  that is electrically coupled to isolation packer element  124   a . Power can then be transmitted via wiring (hidden from view) from the upper magnetic toroidal core  132   a  through the feedthrough  126   a  of isolation packer element  124   a  to a lower magnetic toroidal core  136   a  in an adjacent zone  120 . 
     The lower magnetic toroidal core  136   a  in turn transmits currents wirelessly via the electrically-conductive production tubing  110  to an upper magnetic toroidal core  132   b  that is electrically coupled to isolation packer element  124   b . Power can then be transmitted by wiring disposed within the feedthrough  126   b  of the isolation packer element  124   b  to a lower magnetic toroidal core  136   b  in the next zone. Generally, power can be transmitted within a number of isolated zones  120  from a lower magnetic toroidal core  136  to an upper magnetic toroidal core  132  in this manner. Similarly power can be transmitted across adjacent zones  120  using wiring disposed within the feedthroughs  126  of the corresponding isolation packer elements  124 , where one end of the wiring is coupled to an upper magnetic toroidal core  132  and the other end of the wiring is coupled to a lower magnetic toroidal core  136 . 
     More specifically, by transformation of magnetic fields in an upper magnetic toroidal core  132  to a “secondary winding” on the core, the transformed current is manifested in the wire of the winding and penetrated through isolation packer element  124  to the lower side of the packer element  124  via an insulated and pressure sealed feed-through. This wire carrying the secondary current is then attached to a similar winding on lower magnetic toroidal core  136  on the lower side of the packer element  124  that will launch current down the production tubing  110  within that zone  120  below that packer element  124 . By replication of this technique at each isolation packer element  124 , power may be translated through several electrically isolated zones  120 , without the use of annulus-located cabling. In addition to power/current, data can also be similarly transmitted across the zones  120  using this transmission system. Absent the wiring in the feedthrough  126 , the tubing  110  in a zone  120  is electrically isolated from the tubing  110  in an adjacent zone  120  by the isolation packer element  124  that separates those two zones  120 . 
       FIGS. 2A, 2B, and 2C  show a wiring diagram, a schematic diagram, and another schematic diagram, respectively, involving a core  232  of an example power delivery system according to certain example embodiments. Referring to  FIGS. 1, 2A, 2B, and 2C , in certain embodiments, the core  232  is toroidal and interacts with two wires  257  (wire  257 - 1  and wire  257 - 2 ) of an electrical cable  256 . Wire  257 - 1  carries inbound current and is wound around the core  232  multiple times. The current flowing through wire  257 - 1  induces a current-generated magnetic field (H-field) vector within the core, which in turn induces a current sheet that flows axially through the center of the core  232 . When a tubing pipe  210  is disposed through the center of the core  232 , this current sheet flows along the tubing pipe  210 . When there is an electrical short (discussed below) between the tubing  210  and the adjacent casing  209 , then the current that flows along the tubing  210  returns along the casing  209 . The distal end of wire  257 - 1  and wire  257 - 2  are joined together, essentially creating a continuous wire  257 . Wire  257 - 2  carries the return or outbound current back through the cable  256  to the source of the current. 
     In  FIG. 2C , the schematic of  FIG. 2B  is expanded. Specifically, the continuous wire  257  is shown partially disposed within a feedthrough  226  of a packer  224 . Wire  257 - 1  and wire  257 - 2  can be in the same feedthrough  226 , or the packer can have multiple feedthroughs  226 , with wire  257 - 1  being disposed in one feedthrough  226  and wire  257 - 2  being disposed in the other feedthrough  226 . The wire  257  in this case is a single continuous wire that wraps around core  232  at one end of the packer, and that also wraps around core  236  at the other end of the packer. The packer  226  electrically isolates zone  220   a  from zone  220   b . As a result, the current induced through core  232  flows in a loop between tubing  210  and casing  209  within zone  220   b , and the current flowing in a loop along tubing  210 , through core  236 , and returning along the casing  209  induces current in the wire  257  wrapped around core  236  within zone  220   a.    
       FIG. 3  illustrates a typical current flow scheme at a packer assembly  370  according to certain example embodiments. Referring to  FIGS. 1-3 , the packer assembly  370  includes a packer element  324  and at least one other component. In this case, the packer assembly  370  includes the packer element  324 , toroid  332 , toroid  336 , and a number of electrically-conductive cleats  371  disposed along the outer perimeter of the packer element  324 . When the tubing  310  is coupled to the packer assembly  370 , the cleats  371  make an ohmic (resistive) connection to the tubing string  310 . In other words, there is electrical continuity between the cleats  371  and the tubing  310  when the tubing  310  is coupled to the packer assembly  370 . The cleats  371  can be protracted when the packer assembly  370  is disposed at a desired location within the wellbore. When this occurs, the cleats  371  make contact with the casing  309  and create the short  375 , which provides a return path for the current that originates from the power source (e.g., power source  195 ) and flows through the tubing  310 . The cleats  371  also mechanically anchor the packer assembly  370  to the casing  309 . 
     Current in zone  320 - 1  on production tubing  310  above packer assembly  370  induces an attendant magnetic field in an upper magnetic toroidal core  332  (enhanced by the special core material). In certain example embodiments, the current path  385  in the tubing-casing skins constitutes one full turn of a distributed winding (on the associated toroidal core), a winding we will here dub, ‘primary’ winding, as current in the production tubing  310  returns back in the casing  309  inner diameter (ID) skin and passes the upper magnetic toroidal core  332  inside and outside that core  332 . There is a wire winding of several turns on the upper magnetic toroidal core  332  that is considered a ‘secondary’ winding. 
     One or more leads (also called wires herein) from this secondary winding are fed through the packer assembly  370  housing in a sealed feedthrough  326  to the other (lower) side of the packer assembly  370 . The one or more wires are hidden from view in this example. If shown, there can be a single continuous wire that wraps around core  332  and core  336 , while a remainder of the wire is disposed within the feedthrough  326 . This winding in the upper magnetic toroidal core  332  then drives a similar winding on a lower magnetic toroidal core  336 , inducing a current in a current path  385 - 2  on the production tubing  310  in the string section (zone  302 - 2 ) below this packer assembly  370 . In certain example embodiments, the packer assembly  370  is manufactured with the upper toroidal core  332  and the lower magnetic toroidal core  336  integrated and wired in, and can be assembled on site by the completion crew in a conventional manner with no special techniques required. 
     In certain applications, the winding turn ratios of each magnetic toroidal core (e.g., core  332 , core  336 ) allow the advantage of relatively high current in the production tubing  310 , and thus low voltage between the production tubing  310  and casing  309  so that the insulation requirements of the wellbore annulus (cavity  388 ) are reduced. Some salt-based packer fluids may have adequately high resistive nature for manageable system power loss, reducing some of the “insulative” character of a possible needed packer fluid. Some high density packer fluids may become more ‘conductive’ as an electrical conductor as the density and salt character increases. This may or may not pose a challenge for the power and communications ability of a particular zone  320 , but should be considered in the early design phase for the completion. 
       FIG. 4  illustrates how magnetic coupling works in a cased well construct. Referring to  FIGS. 1-4 , magnetic coupling occurs where the H-field is ‘collected’ by the internal toroidal core magnetic material, intersected by the current-generated magnetic field (H-field) vector  451  shown in  FIG. 4 . Electrical current always generates an attendant magnetic field, as explained by Faraday&#39;s Law of Induction. These cores (e.g., core  332 ) use materials in their bulk that have a high susceptance′ to magnetic fields that, in a way, concentrate available field density. The toroidal shape of the core can be used to act as a magnetic antenna in this application, where the system current  486  follows the current path  485  defined as being on the tubing surface  410  and returning on the inside of the casing  409 , effectively fully wrapped around the toroidal core. 
     In certain example embodiments, an effective magnetic ‘antenna’ in the present application may be a toroidal, magnetic core with the largest outer diameter (OD) possible (as large as the ‘drift’ diameter) and the tightest possible fit around the outer surface of the tubing  410 . The closer the “skin” current flow is to the core magnetic material, the better the coupling to the magnetic fields is, and the effective power-loss per coupling is reduced. Limitations on these mechanical dimensions are understood by one having ordinary skill in the art for applicable and safe, useable packer designs. It should be noted that this is specifically an alternating current (AC) current application; direct current (DC) current will not transfer power continuously in these example power transmission systems using magnetically coupled applications. 
     The current (I)  486  runs along the surface of the tubing  410  and on the inside surface of the casing  409  to form the current path  485  in a complete loop. The bulk of the current flows in a thin outer layer of the conductive metals, generally referred to as the current “skin-depth”. The depth or cross-section of the metal conductor where conduction is present improves as the skin-thickness increases (lower Z-axis resistance per unit length) deeper into the wall of the conductor  410 . The effective thickness gets thinner as the operating frequency of the current  486  increases. In certain example embodiments, communications may be operated at lower frequencies as these losses are reduced as that “skin” gets thicker. In certain embodiments, where power requirements increase, power is transmitted at frequencies of 400-2000 Hz and lower. 
     As shown in  FIG. 4 , the dashed line portion of the current path  485  implies circuit completion at a hanger or packer to the right of the drawing, where the tubing  410  and casing  409  become electrically connected or terminated by another packer or device that brings the tubing  410  and casing  409  in electrical connection. There are a number of options available for initial power and communications feed at the ground level including “hot-string” techniques described, for example, in U.S. Pat. No. 9,316,063, to the customary cabled drop from hanger to top packer. 
       FIG. 5  illustrates additional details of the magnetic field generated by the current sheets that surround a magnetic toroidal core cross-section. Referring to  FIGS. 1-5 , the current  586  in the production tubing  510  and the inside wall of the casing  509  are wave-generated and “coherent”, which means that, at any point in time, they are opposite in direction, the same in signal timing, and essentially wrap around the magnetic material of the core  532 . The coaxial construct of a classic well produces a wave guide, thus the currents (both power and communications) are the result of a “traveling wave”. This forces the E-field and magnetic field (shown by magnetic field vector  551  in  FIG. 5 ) into the annular volume  588  of the guide away from the two conductors (in this case, the tubing  510  and the casing  509 ). Current remains in the ‘skin’ of these conductors. This simplifies the skin-depth calculation as there is no magnetic term in that skin-depth calculation. In other words, there is no further loss due to magnetic materials (steel, etc.) in the tubing  510  and the casing  509 . 
     In addition, the ‘sheet-current’ (represented by the current  586  in the tubing  510  in  FIG. 5  and normally called ‘J’), is the current density where current  586  is the integral of J over the conductive area involved. The core material in the cores  532  (or other cores, such as core  336 ) described herein may be made of various alloys of ferrite or a special metal tape, such as layers of magnetic grade iron alloy that capture and concentrate the field inside the effective current loop. In certain example embodiments, a copper winding  557  for the ‘secondaries’ may be employed around the core  532  to improve efficiency. The type of material of the core  532  can depend on one or more of a number of factors. For example, the type of material of the core  532  can depend on the frequencies expected for both power and communications. 
     The induced voltage in the attached, multi-turn winding  557  (core “secondary”) is transformed from the voltage between the tubing  510  and the casing  509  (effectively one turn) to a voltage that is multiplied by the number of secondary turns (e.g. five turns) that are wound around the cross-section of the core  532 . At the same time the current in that multi-turn winding  557  is one-fifth (for five secondary turns) the current  586  in the current sheet of the tubing  510 . The power equation remains the same in that what was reduced in current is balanced by the five-times (for five secondary turns) increase in voltage. In certain embodiments, the “traveling wave” idea also supports the possibility of having a core  532  placed anywhere along the tubing  510  between packers used as a coupler to the system power/communication stream. The wave exists all along the zone or cell structure and makes the connection to power and signals in that wave easily accessible. 
     Liquids and solids can present a resistive path across the annular volume  588  between the tubing  510  and casing  509  (a ‘shunt-current’ path) that will spill off power to heating material (e.g., brine, salt included fluids) in the annular volume  588 . A packer fluid that has a bulk electrical resistive character would shift the equation. System designers would favor high current  586  on the tubing  510 , less voltage across the annulus  588 . That annular power loss is quantified by the equation P 1 =E 2 /R where the R is the effective resistance, tubing  510  to casing  509 , of the annulus volume  588 . If the R is very large (toward an open circuit), the losses to the annular volume  588  are very low. The advantage of the above magnetically coupled zone transformation resulting from the cores (e.g., core  532 ) having a large turns-ratio puts high current  586  on the tubing  510  and very low voltage in the annular volume  588  where resistive (semi-conductive) packer fluids may be needed and are tolerable. These relatively small magnetic cores  532  capture the magnetic field  551  from the current passing through and around the core  532 . Not all of the magnetic field  551  can be effectively captured in most cases due to mechanical dimensions and product availability or custom sizes. However most applications presented by the design of a conventional well construct will allow a practical solution for systems (e.g., electrical devices  750 , described below) that require approximately ½ kW or less of continuous power. 
       FIG. 6  illustrates a close-up of a midstream portion of an isolated zone  620 , and is intended to show another case of the current  686  on tubing  610  and inside the casing wall  609 . The current sheets (sharing the direction with the current  686  in the tubing  610 ) link magnetic couplers (toroidal cores  636  and  632 ) to that flow of current  686  such that anywhere along the tubing  610  between core  636  and core  632 , power and/or communications access can be harvested for use by one or more electrical devices. The packer shorts  675  (in this case, short  675   a  and  675   b ), which are each a short between the tubing  610  and the casing  609 , are shown in  FIG. 6 . These shorts  675  represent the boundaries of this completion cell  620  (zone  620 ), which creates a circuit closed loop where those currents  686  and corresponding current sheets are created by the induced current from one magnetic core  636  and/or the other magnetic core  632 . 
     The winding wires  657  of the core secondaries exit the zone  620  through the feedthrough  626  of the packer  624  to link to the next adjacent zone  620  or cell  620 . For example, winding wire  657   a  acts as the secondary wrapped around core  636  and are disposed within the feedthrough  626   a  of the packer  624   a  to act as the secondary wrapped another core (e.g., core  632   b ) in an adjacent zone  620 . As another example, winding wire  657   b  acts as the secondary wrapped around core  632  and are disposed within the feedthrough  626   b  of the packer  624   b  to act as the secondary wrapped another core (e.g., core  636   c ) in an adjacent zone  620 . This system and process is replicated at each cell  620  or zone  620 . It should be noted that each winding wire  657  (e.g., winding wire  657   a ) can be a single continuous wire. Alternatively, a winding wire  657  can be two wires whose distal ends are joined together proximate to the core that they are wrapped around. 
     A completion system may have cable feed to a penetrated, top packer (e.g., packer  128 ) from the hanger. In cases where the top packer is a considerable distance down, this would eliminate the need for centralizers and high resistance (insulating) packer fluids. The following (further downhole) production zones would then use the example magnetically coupled packer approach, such as shown and described herein, for power and communication feed through the producing cells  620  below (further downhole). Each zone  620  or electric cell  620  is treated as autonomous from all neighboring cells  620  due to the packer/casing shorts  675  therebetween, where the only link or supply line is the winding wires  657  disposed in the feedthrough  626  of each packer  624  to the next cell  620 . 
       FIG. 7  illustrates a close-up of a midstream portion of an isolated zone  720 , having an electrical device  750  (in this case, a sensor system) placed within the cell  720  or zone  720  along the tubing  710 . An electrical device  750  can be any device that uses power to operate and/or communicate. Examples of an electrical device  750  can include, but are not limited to, a sensor (e.g., pressure, temperature, flow), a solenoid (e.g., for a valve), a switch, a battery, a capacitor, and a relay. The example system can be designed to transmit both operational power for active circuits and small motorized devices. Also, using power-conditioning, energy-storage techniques could invoke valve and other mechanical functions in each zone (e.g., zone  720 ) requiring significant, short-lived mechanical force. 
     In example embodiments, in addition to or in the alternative of a sensor system, the electrical device  750  can include a solenoid (for a valve), fluid identifying sensors, flow measuring devices, pressure sensors, and temperature sensors. The electrical devices  750  can be placed at any location along the cell  720  or zone  720  along the tubing  710 . In certain embodiments, the electrical device  750  can be a multitude of remote sensing and control devices located throughout the zone  720 . 
     In some cases, as shown below with respect to  FIG. 8 , a zone  720  can be very long and/or there are multiple electrical devices  750  spread out within the zone  720 . In such a case, one or more of these electrical devices  750  can be linked to the example power delivery system within the zone  720  via an additional core (e.g., core  736   b ) and/or another winding (e.g., winding  757   c ) around a cell-terminating core (core  732 ) at a packer  724  or packer assembly, as applicable. An additional winding (e.g., winding  757   c ) can be included on any of the cores (e.g., core  736 ) in the zone  720 , regardless of location (in the middle of the tubing  710 , at a packer  724 ) of the core within the zone  720 . Each winding (e.g., winding  757   a ) can be of any number of turns to accommodate the operation and voltage needs of electrical device  750  coupled to and receiving power from the winding. Higher turns ratio could be advantageous for a power conditioning unit where a relatively high voltage will be capacitor-stored, for a necessary high-action mechanical function. 
     The electrical devices  750  (e.g., sensors) may be placed anywhere in the zone  720  proximate to the tubing  710  and can be co-located with any desired function. One or more of the electrical devices  750  can be part of a packer assembly, included at a packer core with an extra winding on the packer core. The complexity of the electronics in a number of sensor packages is only governed by the expected temperature range those electronic devices will be exposed to. In short, if the environmental thermal character of the zone is not extreme, highly complex, processor-based electronics could be an option as an electrical device  750  for the string design. This would lend itself to individually addressed sensor/valve stations along any zone section where those favorable thermal conditions exist. 
     In certain example embodiments, there can be multiple electrical devices  750  in a zone (e.g., zone  720 ). In addition, or in the alternative, there can be multiple zones with one or more electrical devices  750 . In such cases, each electrical device  750  can have an assigned serial communications address so that functions within a particular zone  720  and/or between zones can be treated and/or interrogated individually or totally. In certain applications, there may be a need to control contact or direct electrical conduction of tubing  710  to casing  709  in the inter-zone areas of tubing/casing discipline (tubing  710  centralization in the wellbore). Mid-zone “shorts”  775  (between each of the packers  726 ) between tubing  710  and casing  709  in a zone  720  can significantly affect the passage of power and signals to any following (downhole) core transformers. Coatings and insulated centralizer techniques can be used as part of the completions design plan to help improve the transmission of power and signals using example embodiments. 
       FIG. 8  shows a schematic of a power delivery system  890  with three zones  820 , broken up to fit the page, according to an example embodiment. Referring to  FIGS. 1-8 , not shown in  FIG. 8  are the usual insulated centralizers or indication of packer fluids. The system  890  of  FIG. 8  can transmit power and data in a subterranean wellbore during completions and/or production operations in accordance with one or more example embodiments. The system  890  of  FIG. 8  is substantially the same as what is described above with respect to  FIGS. 1-7 , except as specifically stated below. For the sake of brevity, the similarities will not be repeated herein below. 
     The example system  890  includes electrical equipment  850  located within three of the zones  820 . In this case, zone  820   a  is adjacent to zone  820   b , which is adjacent to zone  820   c , which is adjacent to zone  820   d . Zone  820   a  and zone  820   b  are separated by a short  875   a  through packer  824   a . Zone  820   b  and zone  820   c  are separated by a short  875   b  through packer  824   b . Zone  820   c  and zone  820   d  are separated by a short  875   c  through packer  824   c . There is no electrical equipment within zone  820   a . Electrical equipment  850   a  is located in zone  820   b , electrical equipment  850   b  is located in zone  820   c , and electrical equipment  850   c  is located in zone  820   d.    
     Zone  820   b , zone  820   c , and zone  820   d  each have three cores, meaning that an extra core has been added to each of those zones, as described with respect to  FIG. 7  could be a configuration of the system  890 . Specifically, in zone  820   b , core  836   a  is coupled to packer  824   a , core  832   b  is coupled to packer  824   b , and core  836   b  is disposed therebetween, adjacent to electrical device  850   a . In this way, core  836   b  can be used to provide power directly to electrical device  850   a  based on the current flowing through tubing  810  induced by and between core  836   a  and core  832   b.    
     In addition, in zone  820   c , core  836   c  is coupled to packer  824   b , core  832   c  is coupled to packer  824   c , and core  836   d  is disposed therebetween, adjacent to electrical device  850   b . In this way, core  836   d  can be used to provide power directly to electrical device  850   b  based on the current flowing through tubing  810  induced by and between core  836   c  and core  832   c . Further, in zone  820   d , core  836   e  is coupled to packer  824   c , another core (not shown) is coupled to another packer (not shown), and core  836   f  is disposed therebetween, adjacent to electrical device  850   c . In this way, core  836   f  can be used to provide power directly to electrical device  850   c  based on the current flowing through tubing  810  induced by and between core  836   e  and the additional downstream core. As an alternative to having a third core, as discussed above with respect to  FIG. 7 , one of the cores (e.g., core  832   b ) coupled to a packer (e.g., packer  824   b ) can use an additional winding on the core above or below the electrical device (e.g., electrical device  850   a ). 
       FIG. 9A  shows a schematic of a packer assembly  970  an unset condition and with embedded inductive coupling and electrical devices  950 , according to an example embodiment.  FIG. 9B  shows a schematic of the packer assembly  970  of  FIG. 9A  in a set condition according to an example embodiment. Referring to  FIGS. 1-9B , the components of the packer assembly  970  are substantially the same as those described above, and for the sake of brevity, the similarities may not be repeated herein. The packer assembly  970  is in an unset position because the packer seals  967  are deflated, and the upper slip section  966  and the lower slip section  964  are retracted (not protracted). As a result, there is no pressure separation above and below the packer  924 . In other words, the packer seals  967 , the upper slip section  966 , and the lower slip section  964  of the packer  924  fail to contact the casing  909 , allowing the cavity  988  to be substantially continuous (from a pressure standpoint) along the length of the packer assembly  970 , forming a single zone  920 . 
     Since the packer assembly  970  in this case has embedded inductive coupling, core  932  is embedded into the top of the packer assembly  970 , and core  936  is embedded into the bottom of the packer assembly  970 . Core  932  and core  936  are coupled to each other by winding wires  957 , which are disposed in the feedthrough  926  in the packer assembly  970  and are wound around core  932  and core  936 . Electrical device  950  is also embedded into the bottom of the packer assembly  970  and is provided power from winding wire  957  or a different winding wire wrapped around core  936 . 
     In  FIG. 9B , the packer seals  967 , the upper slip section  966 , and the lower slip section  964  of the packer  924  are all expanded/protracted so that they abut against the inner wall of the casing  909 . As a result, zone  920   a  is physically separated from zone  920   b , and a pressure separation is created between the two zones  920 . The upper slip section  966  and the lower slip section  964  can be electrically-conductive and act as the cleats (not shown in  FIGS. 9A and 9B ) described above in that the slip sections can create a short with the casing  909 . Alternatively, the packer assembly  970  can include a number of cleats to create the shorts that allow current flowing along the tubing  910  to return along the casing  909  within a zone  920  (e.g., zone  920   a , zone  920   b ). The electrical device  950  can thus be used to measure temperature, pressure, flow, and/or other parameters in zone  920   b  below the packer  924 . 
       FIG. 10  shows a schematic of a single zone  1020  simulator that was tested in a laboratory to verify the practical use of the example system of power and data transmission. A magnetic toroidal core  1032  and core  1036  were placed at either end of the zone  1020 , and coupled to the current sheet in the tubing  1010 -casing  1009  loop-current along the path shown for current  1086 . The electrical device  1050  receives power induced from core  1036  using winding wires  1057 . 
       FIG. 11  shows a schematic of a dual-zone  1120  simulator that was tested in a non-idealized laboratory arrangement to measure power loss across a zone  1120   b . A magnetic toroidal core  1132   a  and core  1136   a  were placed at either end of zone  1120   a , and coupled to the current sheet in the tubing  1110 -casing  1109  loop-current along path shown for current  1186   a . Similarly, a magnetic toroidal core  1132   b  and core  1136   b  were placed at either end of zone  1120   b , and coupled to the current sheet in the tubing  1110 -casing  1109  loop-current along the path shown for current  1186   b.    
     Initial lab results indicate that a five-zone completion could provide 10-15 watts at zone  1120   b  with about 80 watts applied by the power source  1195  (e.g., at the surface level). Specified custom made cores for intended power and communication frequencies of a maximum OD, minimum ID design (as mechanically practicable), could increase the efficiency of the multi-zone system significantly (which was not done for the laboratory tests). However, an optimized system could be employed to supply power of about 0.5 KVA and below to an electrical device or devices using this example system and technique. 
     The systems, methods, and apparatuses described herein allow for transmitting power and data within a wellbore. Supply of power using magnetic toroidal cores and existing wellbore hardware, such as a tubing string and casing, reduces the need for conventional power cabling completion insertions within each zone of a wellbore. The application of example embodiments may employ relatively high current and moderately high voltage use of the well structure. 
     Although embodiments described herein are made with reference to example embodiments, it should be appreciated by those skilled in the art that various modifications are well within the scope and spirit of this disclosure. Those skilled in the art will appreciate that the example embodiments described herein are not limited to any specifically discussed application and that the embodiments described herein are illustrative and not restrictive. From the description of the example embodiments, equivalents of the elements shown therein will suggest themselves to those skilled in the art, and ways of constructing other embodiments using the present disclosure will suggest themselves to practitioners of the art. Therefore, the scope of the example embodiments is not limited herein.