Systems And Methods For Multi-Zone Power And Communications

Abstract

A system, method and device may be used to provide power and monitor conditions in a borehole. Well tubing and casing act as a conductive pair for delivering power wirelessly to isolated zones defined between packer elements. Data signals are similarly transmitted. The packer elements include magnetic toroidal cores for power and signal transmission via inductively coupling.

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'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 124a, 124b, . . . 124n (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 124n) 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 132a that is electrically coupled to isolation packer element 124a. Power can then be transmitted via wiring (hidden from view) from the upper magnetic toroidal core 132a through the feedthrough 126a of isolation packer element 124a to a lower magnetic toroidal core 136a in an adjacent zone 120.

The lower magnetic toroidal core 136a in turn transmits currents wirelessly via the electrically-conductive production tubing 110 to an upper magnetic toroidal core 132b that is electrically coupled to isolation packer element 124b. Power can then be transmitted by wiring disposed within the feedthrough 126b of the isolation packer element 124b to a lower magnetic toroidal core 136b 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 220a from zone 220b. As a result, the current induced through core 232 flows in a loop between tubing 210 and casing 209 within zone 220b, 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 220a.

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'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 P₁=E²/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 675a and 675b), 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 657a acts as the secondary wrapped around core 636 and are disposed within the feedthrough 626a of the packer 624a to act as the secondary wrapped another core (e.g., core 632b) in an adjacent zone 620. As another example, winding wire 657b acts as the secondary wrapped around core 632 and are disposed within the feedthrough 626b of the packer 624b to act as the secondary wrapped another core (e.g., core 636c) 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 657a) 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 736b) and/or another winding (e.g., winding 757c) around a cell-terminating core (core 732) at a packer 724 or packer assembly, as applicable. An additional winding (e.g., winding 757c) 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 757a) 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 820a is adjacent to zone 820b, which is adjacent to zone 820c, which is adjacent to zone 820d. Zone 820a and zone 820b are separated by a short 875a through packer 824a. Zone 820b and zone 820c are separated by a short 875b through packer 824b. Zone 820c and zone 820d are separated by a short 875c through packer 824c. There is no electrical equipment within zone 820a. Electrical equipment 850a is located in zone 820b, electrical equipment 850b is located in zone 820c, and electrical equipment 850c is located in zone 820d.

Zone 820b, zone 820c, and zone 820d 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 820b, core 836a is coupled to packer 824a, core 832b is coupled to packer 824b, and core 836b is disposed therebetween, adjacent to electrical device 850a. In this way, core 836b can be used to provide power directly to electrical device 850a based on the current flowing through tubing 810 induced by and between core 836a and core 832b.

In addition, in zone 820c, core 836c is coupled to packer 824b, core 832c is coupled to packer 824c, and core 836d is disposed therebetween, adjacent to electrical device 850b. In this way, core 836d can be used to provide power directly to electrical device 850b based on the current flowing through tubing 810 induced by and between core 836c and core 832c. Further, in zone 820d, core 836e is coupled to packer 824c, another core (not shown) is coupled to another packer (not shown), and core 836f is disposed therebetween, adjacent to electrical device 850c. In this way, core 836f can be used to provide power directly to electrical device 850c based on the current flowing through tubing 810 induced by and between core 836e 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 832b) coupled to a packer (e.g., packer 824b) can use an additional winding on the core above or below the electrical device (e.g., electrical device 850a).

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 920a is physically separated from zone 920b, 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 920a, zone 920b). The electrical device 950 can thus be used to measure temperature, pressure, flow, and/or other parameters in zone 920b 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 1120b. A magnetic toroidal core 1132a and core 1136a were placed at either end of zone 1120a, and coupled to the current sheet in the tubing 1110-casing 1109 loop-current along path shown for current 1186a. Similarly, a magnetic toroidal core 1132b and core 1136b were placed at either end of zone 1120b, and coupled to the current sheet in the tubing 1110-casing 1109 loop-current along the path shown for current 1186b.

Initial lab results indicate that a five-zone completion could provide 10-15 watts at zone 1120b 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.

Claims

1. A packer assembly for disposal within a subterranean wellbore lined by a casing, the packer assembly comprising:

a packer comprising an upper end, a lower end, and a feedthrough that traverses the packer from the upper end to the lower end, wherein the upper end is configured to couple to a first tubing string, wherein the lower end is configured to couple to a second tubing string;

a first core disposed around the second tubing string adjacent to the lower end of the packer; and

an electrical wire disposed within the feedthrough of the packer, wherein the electrical wire has a proximal end and a distal end wrapped around the first core,

wherein the proximal end of the electrical wire is configured to receive a first power from a power source disposed above the upper end of the packer, wherein the distal end of the electrical wire is configured to use the first power to induce a second power in the first core, wherein the second power in the first core generates a first current that flows on the second tubing string away from the first core.

2. The packer assembly of claim 1, wherein the power source comprises a second core disposed around the first tubing string adjacent to the upper end of the packer, wherein the proximal end of the electrical wire is wrapped around the second core.

3. The packer assembly of claim 2, wherein the packer, the first core, the second core, and the electrical wire form a single integral piece.

4. The packer assembly of claim 2, wherein the second core is configured to receive a second current from a third core of an additional packer assembly, wherein the third core is disposed around the first tubing string.

5. The packer assembly of claim 1, wherein the proximal end of the electrical wire is coupled to a power source at a surface above the subterranean wellbore.

6. The packer assembly of claim 1, further comprising:

at least one cleat disposed on an outer surface of a body of the packer, wherein the at least one cleat comprises electrically conductive material and is configured to abut against a casing of the subterranean wellbore, wherein the at least one cleat further has electrical continuity with the second tubing string when the second tubing string is coupled to the packer.

7. The packer assembly of claim 6, wherein the at least one cleat is retractable relative to the body of the packer.

8. The packer assembly of claim 1, wherein the packer comprises a body, wherein the body has disposed thereon at least one seal and at least one slip section, wherein the at least one seal and the at least one slip section are configured to abut against a casing of the subterranean wellbore to provide a pressure separation within the subterranean wellbore above the packer and the subterranean wellbore below the packer.

9. The packer assembly of claim 1, wherein the first core comprises magnetic properties.

10. 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 comprising:

a power source disposed proximate to a surface at an opening of the subterranean wellbore, wherein the power source generates a first power;

a first tubing string segment disposed within the cavity;

a first packer mechanically coupled to a first distal end of the first tubing string within the cavity of the subterranean wellbore, wherein the first packer has a first feedthrough disposed therein along a first height of the first packer;

a second tubing string segment mechanically coupled to a first bottom end of the first packer within the cavity of the subterranean wellbore;

a first core disposed around the second tubing string segment adjacent to the bottom end of the first packer and the first feedthrough; and

a first electrical wire disposed within the first feedthrough of the first packer, wherein 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,

wherein the first power flowing through the first electrical wire disposed around the first core induces a second power in the first core, wherein 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.

11. The system of claim 10, wherein the first packer comprises a body, wherein the body has disposed thereon at least one seal and at least one slip section, wherein the at least one seal and the at least one slip section are configured to abut against the casing within the cavity of the subterranean wellbore to provide a pressure separation within the cavity of the subterranean wellbore above the first packer and the subterranean wellbore below the first packer.

12. The system of claim 10, further comprising:

a second core disposed around the second tubing string segment; and

a second electrical wire wrapped around the second core, wherein the first current induces a third power in the second electrical wire.

13. The system of claim 12, further comprising:

at least one first electrical device coupled to the second electrical wire and disposed adjacent to the second core, wherein the at least one electrical device operates using the third power.

14. The system of claim 12, further comprising:

a second packer coupled to a second distal end of the second tubing string segment, wherein the second core and the at least one electrical device are disposed adjacent to the second packer, wherein the second packer has a second feedthrough disposed therein along a second height of the second packer, wherein the second electrical wire is disposed within the second feedthrough;

a third tubing string segment mechanically coupled to a second bottom end of the second packer within the cavity of the subterranean wellbore; and

a third core disposed around the second tubing string segment adjacent to the bottom end of the second packer and the second feedthrough,

wherein the second electrical wire is further wrapped around the third core,

wherein the third power flowing through the second electrical wire disposed around the third core induces a third power in the third core, wherein the third power in the third core generates a second current that flows on the third tubing string away from the third core further into the subterranean wellbore.

15. The system of claim 14, further comprising:

a fourth core disposed around the third tubing string segment;

a third electrical wire wrapped around the fourth core, wherein the second current induces a fourth power in the third electrical wire; and

at least one first electrical device coupled to the third electrical wire and disposed adjacent to the fourth core, wherein the at least one electrical device operates using the fourth power.

16. The system of claim 14, wherein the second packer comprises at least one first cleat disposed on a first outer surface of the second packer, wherein the at least one first cleat comprises electrically conductive material and abuts against the casing.

17. The system of claim 16, wherein the casing, the second tubing string segment, and the third tubing string segment are electrically conductive, wherein the at least one first cleat forms a first short that electrically isolates the second tubing string segment from the third tubing string segment.

18. The system of claim 17, wherein the first packer comprises at least one second cleat disposed on a second outer surface of the first packer, wherein the at least one second cleat comprises the electrically conductive material and abuts against the casing, wherein the at least one second cleat forms a second short that electrically isolates the second tubing string segment from the first tubing string segment.

19. The system of claim 14, wherein the first current flows in a loop down the second tubing string segment and up the casing between the first core and the second core.

20. The system of claim 12, further comprising:

a second packer coupled to a second distal end of the second tubing string segment;

a third core disposed around the second tubing string segment toward a second distal end of the second tubing string segment;

a second electrical wire wrapped around the second core, wherein the first current induces a third power in the second electrical wire; and

at least one first electrical device coupled to the second electrical wire and disposed adjacent to the second core, wherein the at least one electrical device operates using the third power.