The present application presents an alteration and modification of U.S. Pat. No. 8,519,865, to Hall et al., entitled Downhole Coils, issued Aug. 27, 2013, which is incorporated herein by this reference.
U.S. Pat. No. 6,670,880, to Hall et al., entitled Downhole Data Transmission System, issued Dec. 30, 2003, is incorporated herein by this reference.
The present invention relates to downhole drilling, and more particularly, to systems and methods for transmitting power and data to components of a downhole tool string. Downhole sensors, tools, telemetry components and other electronic components continue to increase in both number and complexity in downhole drilling systems. Because these components require power to operate, the need for a reliable energy source to power these downhole components is becoming increasingly important. Constraints imposed by downhole tools and the harsh downhole environment significantly limit options for delivering power and data to downhole components.
As downhole instrumentation and tools have become increasingly more complex in their composition and versatile in their functionality, the need to transmit power and/or data through tubular tool string components is becoming ever more significant. Real-time logging tools located at a drill bit and/or throughout a tool string require power to operate. Providing power downhole is challenging, but if accomplished it may greatly increase the efficiency of drilling. Data collected by logging tools are even more valuable when they are received at the surface real time.
The application presents an alteration and modification to the '865 reference above. A large portion of the summary and detailed description are taken from said reference in relation to the prior art figures. The following portion of the summary relates to
This application discloses an inductive coupler and a method for producing the inductive coupler for use in a downhole tool such as a drillpipe or bottom hole assembly. The inductive coupler may comprise an annular magnetically conductive electrically insulating (MCEI) U-shaped single piece trough or mold comprising an annular channel. The annular channel may comprise a first perforation and one or more second perforations. Typically, inductive couplers for use in downhole applications may be comprised of multiple MCEI trough segments arranged end for end to form an annular ring-like structure. See (Prior Art)
The ingot may comprise a first end and a second end. A first socket may be cast in the ingot adjacent the first end. One or more second sockets may be cast in the ingot adjacent the second end. The sockets may be cast when the ingot is cast in the channel or the sockets may be formed after the ingot is cast by machining. A first perforation and one or more second perforations may be formed in the bottom of the annular channel. The perforations may be formed by machining after the ingot is cast into the channel of the mold. The first perforation may be aligned with the first socket and the one or more second perforations may be aligned with the one or more second sockets. The respective sockets may house electrical connections. The first socket may house an electrical connection to a ground pin in the downhole tool. The one or more second sockets may house electrical connections to cables within the downhole tools. The cables may be connected to electronic equipment in the drill string or downhole tool. One or more cables may be attached to a similarly configured inductive coupler at the opposite end of the drill pipe or within the downhole tool. The alignment of the perforations with the respective sockets allows for cable access through the MCEI mold to the make an electrical connection with the ingot.
The channel in the MCEI mold may comprise one or more cleats projecting into the ingot thereby securing the ingot within the channel. The ingot may comprise one or more cleats projecting into the channel as a means of securing the ingot within the channel. The ingot may comprise annular flutes and the channel also may comprise annular flutes. The annular flutes of the ingot may couple with the annular flutes of the channel. The annular flutes may assist in securing the ingot within the annular channel. Also, the annular flutes may increase the surface area of the ingot thereby increasing the strength of the electromagnetic field between adjacent inductive couplers. The ingot may comprise an annular internal passageway within the ingot. The passageway may contribute resiliency to the ingot. Also, the passageway may promote rigidity in the ingot. An electrical cable may run through the passageway.
A nonelectrically conductive seal may enclose the ingot within the channel. A seal seat may be provided in the wall of the channel to seal the ingot from downhole fluids and to fix the seal over the ingot. The seal may act as a channel filler protecting the ingot from contamination from the downhole environment. Also, seals may be provided for the respective sockets and electrical connections, sealing the ingot and the respective sockets and electrical connections against downhole contamination.
The inductive coupler may be produced by providing an annular MCEI U-shaped mold comprising an annular channel and casting an electrically conductive molten metal or metal alloy into the channel, thereby producing an annular electrically conducting ingot.
The ingot may have a first end and a second end. A first socket may be formed proximate the first end and a second socket may be formed proximate the second end. The respective sockets may be formed when the molten metal is cast into the channel, or the respective sockets may be formed by machining after the ingot is cooled. The ingot may comprise one or more second sockets. The sockets may provide a housing for electrical connections to the ingot.
A first perforation and one or more second perforations may be formed in the channel by machining. The respective perforations may be aligned with the respective sockets. The perforations allow cables within the downhole tool or drill string to access electrical connections in the ingot. The first electrical connection may be to a ground pin within the downhole tool. The one or more electrical connections may be to cables connecting the ingot to a similarly configured ingot at the opposite of the drill pipe. And, the cables may connect the ingot to electronics and electrical equipment within the downhole tool.
Seals may be provided to protect the ingot and electrical connections within the channel. A seal may be provided to cover the ingot within the channel. The channel seal may be partially disposed within annular seal seats formed in the walls of the channel. The respective sockets may be provided with seals to prevent contamination from downhole fluids and debris.
The ingot may be provided with an annular passageway formed within the ingot placing a tubular form in the channel prior to casting in the molten metal. The tubular form may be electrically conductive and remain within the ingot or it may be nonelectrically conductive and consumed in the process.
Cleats and flutes may be formed in the channel and in the ingot. The cleats and flutes may be formed in the channel before it is sintered or machined in after sintering. Also, the flutes and cleats may be formed in the ingot when the ingot is cast into the channel by providing a form in the channel comprising the flutes and cleats. The form may be permanent or may be a consumable.
The following portion of the summary is taken from the '865 reference and applies to the prior art figures incorporated herein. The teachings of the remainder of the summary are applicable to the present application except when altered or modified by the teachings of the
In one aspect of the invention, a downhole tool string component comprises a tubular body with at least one end adapted for threaded connection to an adjacent tool string component. The at least one end comprises at least one shoulder adapted to abut an adjacent shoulder of an adjacent end of the adjacent tool string component. An annular inductive coupler is disposed within an annular recess formed in the at least one shoulder, and the inductive coupler comprises a coil in electrical communication with an electrical conductor that is in electrical communication with an electronic device secured to the tubular body. The coil comprises a plurality of windings of wire strands that are electrically isolated from one another and which are disposed in an annular trough of magnetic material secured within the annular recess.
The coil wire may comprise a gauge of between 36 and 40 AWG, and may comprise between 1 and 15 coil turns. The coil wire may comprise between 5 and 40 wire strands. The wire strands may be interwoven. The coil may comprise the characteristic of increasing less than 35.degree. Celsius when 160 watts are passed through the coil. In some embodiments the coil may comprise the characteristic of increasing less than 20.degree. C. when 160 watts are passed through the coil.
The adjacent shoulder of the adjacent downhole tool string may comprise an adjacent inductive coupler configured similar to the inductive coupler. These couplers may be adapted to couple together when the downhole components are connected together at their ends. The inductive coupler and the adjacent inductive coupler may then be adapted to induce magnetic fields in each other when their coils are electrically energized. In such embodiments the inductive coupler may comprise a characteristic of transferring at least 85% energy from the inductive coupler to the adjacent inductive coupler when 160 watts are passed through the coil.
The electronic device that is secured to the tubular body may be a power source. The power source may comprise a battery, generator, capacitor, motor, or combinations thereof. In some embodiments the electronic device may be a sensor, drill instrument, logging-while-drilling tool, measuring-while-drilling tool, computational board, or combinations thereof.
The magnetic material may comprise a material selected from the group consisting of ferrite, a nickel alloy, a zinc alloy, a manganese alloy, soft iron, a silicon iron alloy, a cobalt iron alloy, a mu-metal, a laminated mu-metal, barium, strontium, carbonate, samarium, cobalt, neodymium, boron, a metal oxide, rare earth metals, and combinations thereof. The magnetic material may comprise a relative magnetic permeability of between 100 and 20000.
In another aspect of the invention, a method of transferring power from a downhole tool string component to an adjacent tool string component comprises a step of providing a downhole tool string component and an adjacent tool string component. The components respectively comprise an annular inductive coupler and an adjacent annular inductive coupler disposed in an annular recess in a shoulder of an end of the component. The method further comprises adapting the shoulders of the downhole tool string component and the adjacent tool string component to abut one another when the ends of the components are mechanically connected to one another. The method also comprises a step of mechanically connecting the ends of the components to one another and a step of driving an alternating electrical current through the inductive coupler at a frequency of between 10 and 100 kHz. In some embodiments the frequency may be between 50 and 79 kHz. In some embodiments a square wave may be used. The square wave may be a 170-190 volt square wave.
The inductive coupler and the adjacent inductive coupler may be respectively disposed within annular troughs of magnetic material that are disposed within the respective annular recess of the downhole and adjacent components. At least one of the inductive coupler and adjacent inductive coupler may comprise a coil that comprises a plurality of windings of wire strands, the wire strands each being electrically isolated from one another. At least 85% of the energy comprised by the alternating electrical current being driven through the annular inductive coupler may be inductively transferred to the adjacent inductive coupler when 160 watts are passed through the coil. In some embodiments at least 95% of the energy comprised by the alternating electrical current being driven through the annular inductive coupler may be inductively transferred to the adjacent inductive coupler when 160 watts are passed through the coil.
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The ingot 1515 may comprise a first end 1590 and a second end 1585, as diagramed through cut away 1595. A first socket 1570 may be cast in the ingot 1515 adjacent the first end 1590. One or more second sockets 1635 may be cast in the ingot 1515 adjacent the second end 1585. The sockets 1635/1570 may be cast when the ingot 1515 is cast in the channel or the sockets may be formed after the ingot is cast by machining. A first perforation 1640 and one or more second perforations 1580 may be formed in the bottom 1555 of the annular channel. The perforations 1640/1580 may be formed by machining after the ingot 1515 is cast into the channel of the mold 1500. The first perforation 1640 may be aligned with the first socket 1570 and the one or more second perforations 1580 may be aligned with the one or more second sockets 1635. The respective sockets may house electrical connections 1565. The first socket 1570 may house an electrical connection to a ground pin 1600 in the downhole tool. The one or more second sockets 1635 may house electrical connections 1565 to cables within the downhole tools. The cables may be connected to electronic equipment in the drill string or downhole tool. One or more cables may be attached to a similarly configured inductive coupler at the opposite end of the drill pipe or within the downhole tool. The alignment of the perforations 1640/1580 with the respective sockets allows for cable access through the MCEI mold to the make an electrical connection with the ingot 1515.
The channel 1540/1555 in the MCEI mold 1500 may comprise one or more cleats 1615 projecting into the ingot 1555 thereby securing the ingot within the channel. The ingot 1555 may comprise one or more cleats 1605 projecting into the channel as a means of securing the ingot within the channel. The ingot 1515 may comprise annular flutes 1620 and the channel also may comprise annular flutes 1625. The annular flutes of the ingot 1620 may couple with the annular flutes of the channel 1625. The annular flutes may assist in securing the ingot within the annular channel. Also, the annular flutes may increase the surface area of the ingot thereby increasing the strength of the electromagnetic field between adjacent inductive couplers. The ingot 1515 may comprise an annular internal passageway 1630 within the ingot 1515. The passageway 1630 may contribute resiliency to the ingot. Also, the passageway 1630 may promote rigidity in the ingot. An electrical cable, not shown, may run through the passageway 1630.
A nonelectrically conductive seal 1545 may enclose the ingot 1515 within the channel. A seal seat 1560 may be provided in the wall 1540 of the channel to seal the ingot 1515 from downhole fluids and other contamination and to fix the seal 1545 over the ingot. The seal 1545 may act as a channel filler protecting the ingot 1515 from contamination from the downhole environment. Also, seals 1575 may be provided for the respective sockets and electrical connections, sealing the ingot and the respective sockets and electrical connections against downhole contamination.
The inductive coupler may be produced by providing an annular MCEI U-shaped mold 1500 comprising an annular channel 1540/1555 and casting an electrically conductive molten metal or metal alloy into the channel, thereby producing an annular electrically conducting ingot 1515.
The ingot 1515 may have a first end 1590 and a second end 1585. A first socket 1570 may be formed proximate the first end and a second socket 1635 may be formed proximate the second end. The respective sockets may be formed when the molten metal is cast into the channel, or the respective sockets may be formed by machining after the ingot has cooled. The ingot may comprise one or more second sockets 1635. The sockets may provide a housing for electrical connections to the ingot 1515.
A first perforation 1640 and one or more second perforations 1580 may be formed in the channel by machining. The respective perforations may be aligned with the respective sockets. The perforations allow cables within the downhole tool or drill string to access electrical connections in the ingot. The first electrical connection 1600 may be to a ground pin within the downhole tool. The one or more second electrical connections 1565 may be to cables connecting the ingot to a similarly configured ingot at the opposite of the drill pipe, and the cables may connect the ingot 1515 to electronics and electrical equipment within the downhole tool.
Seals may be provided to protect the ingot and electrical connections within the channel. A seal 1545 may be provided to cover the ingot within the channel. The channel seal 1545 may be partially disposed within annular seal seats 1560 formed in the walls 1540 of the channel. The respective sockets may be provided with seals 1575 to prevent contamination from downhole fluids and debris.
The ingot 1515 may be provided with an annular passageway 1630 that may be formed within the ingot by placing a tubular form, not shown, in the channel prior to casting in the molten metal. The tubular form may be electrically conductive and remain within the ingot or it may be nonelectrically conductive and consumed in the process.
Cleats 1605/1615 and flutes 1620/1625 may be formed in the channel and in the ingot, respectively. The cleats and flutes may be formed in the channel before it is sintered or machined in after sintering. Also, the flutes and cleats may be formed in the ingot when the ingot is cast into the channel by providing a form in the channel comprising the flutes and cleats. The form may be permanent or may be a consumable.
The remainder of the detailed description relates to the prior art figures of the '865 reference. The teachings of the prior art figures are applicable to this disclosure except when modified by this disclosure.
Referring to (Prior Art)
The tool string 12 includes a bottom-hole assembly 22 which may include the drill bit 16 as well as sensors and other downhole tools such as logging-while-drilling (“LWD”) tools, measurement-while-drilling (“MWD”) tools, diagnostic-while-drilling (“DWD”) tools, or the like. The bottom-hole assembly 22 may also include other downhole tools such as heavyweight drill pipe, drill collar, crossovers, mud motors, directional drilling equipment, stabilizers, hole openers, sub-assemblies, under-reamers, drilling jars, drilling shock absorbers, and other specialized devices.
While drilling, a drilling fluid is typically supplied under pressure at the drill rig 14 through the tool string 12. The drilling fluid typically flows downhole through a central bore of the tool string 12 and then returns up-hole to the drill rig 14 through an annulus 20 about the tool string 12. Pressurized drilling fluid is circulated around the drill bit 16 to provide a flushing action to carry cuttings to the surface.
To transmit information at high speeds along the tool string 12, a telemetry network comprising multiple network nodes 24 may be integrated into the tool string 12. These network nodes 24 may be used as repeaters to boost a data signal at regular intervals as the signal travels along the tool string 12. The nodes 24 may also be used to interface with various types of sensors to provide points for data collection along the tool string 12. The telemetry network may include a top-hole server 26, also acting as a network node, which may interface with the tool string 12 using a swivel device 28 for transmitting data between the tool string 12 and the server 26. The top-hole server 26 may be used to transfer data and tool commands to and from multiple local and remote users in real time. To transmit data between each of the nodes 24 and the server 26, data couplers and high-speed data cable may be incorporated into the drill pipe and other downhole tools making up the tool string 12. In selected embodiments, the data couplers may be used to transmit data across the tool joint interfaces by induction and without requiring direct electrical contact between the couplers.
One embodiment of a downhole telemetry network is described in U.S. Pat. No. 6,670,880 entitled Downhole Data Transmission System, having common inventors with the present invention, which this specification incorporates by reference. The telemetry network described in the above-named application enables high-speed bi-directional data transmission along the tool string 12 in real-time. This provides various benefits including but not limited to the ability to control downhole equipment, such as rotary steerable systems, instantaneously from the surface. The network also enables transmission of full seismic waveforms and logging-while-drilling images to the surface in real time and communication with complex logging tools integrated into the tool string 12 without the need for wireline cables. The network further enables control of downhole tools with precision and in real time, access to downhole data even during loss of circulation events, and monitoring of pressure conditions, hole stability, solids movement, and influx migration in real time. The use of the abovementioned equipment may require the ability of passing power between segments of the tool string 12.
Referring now to (Prior Art)
Electronic equipment may be disposed within at least one of the pockets 205A of the downhole tool string component 200A. The electronics may be in electrical communication with the aforementioned telemetry system, or they may be part of a closed-loop system downhole. An electronic device 210A is secured to the tubular body 201A and may be disposed within at least one of the pockets 205A, which may protect the device 210A from downhole conditions. The electronic device 210A may comprise sensors for monitoring downhole conditions. The sensors may include pressure sensors, strain sensors, flow sensors, acoustic sensors, temperature sensors, torque sensors, position sensors, vibration sensors, geophones, hydrophones, electrical potential sensors, nuclear sensors, or any combination thereof. In some embodiments of the invention the electronic device 210A may be a sensor, drill instrument, logging-while drilling tool, measuring-while drilling too, computational board, or combinations thereof. Information gathered from the sensors may be used either by an operator at the surface or by the closed-loop system downhole for modifications during the drilling process. If electronics are disposed in more than one pocket 205A, the pockets 205A may be in electrical communication, which may be through an electrically conductive conduit disposed within the flange separating them. The information may be sent directly to the surface without any computations taking place downhole. In some embodiments the electronic device may be a sonic tool. The sonic tool may comprise multiple poles and may be integrated directly into the tool string. Sending all of the gathered information from the sonic tool directly to the surface without downhole computations may eliminate the need for downhole electronics which may be expensive. The surface equipment may in some cases by able to process the data quicker since the electronics up-hole is not being processed in a high temperature, high pressure environment.
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In general, a downhole generator in accordance with the invention may include a turbine mechanically coupled to an electrical generator. The turbine may receive a moving downhole fluid, such as drilling mud. This downhole fluid may turn blades of the turbine to produce rotational energy (e.g., by rotating a shaft, etc.). This rotational energy may be used to drive a generator to produce electricity. The electrical power produced by the generator may be used to power electrical equipment such as sensors, tools, telemetry components, and other electronic components. One example of a downhole generator which may be used with the present invention is described in U.S. Pat. No. 7,190,084 which is herein incorporated by reference in its entirety. Preferably, however, the turbine is disposed within the bore of the drill string.
Downhole generators may be AC generators that are configured to produce an alternating current with a frequency between about 100 Hz and 2 kHz. More typically, AC generators are configured to produce an alternating current with a frequency between about 300 Hz and 1 kHz. The frequency of the alternating current is proportional to the rotational velocity of the turbine and generator. In some embodiments of the invention, a frequency converter may alter the frequency from a range between 300 Hz and 1 kHz to a range between 10 kHz and 100 kHz. In certain embodiments, an alternating current with a frequency between about 10 kHz and 100 kHz may achieve more efficient power transmission across the tool joints. Thus, in selected embodiments, the frequency of the alternating current produced by the generator may be shifted to a higher frequency to achieve more efficient power transmission.
To achieve this, a rectifier may be used to convert the alternating current of the generator to direct current. An inverter may convert the direct current to an alternating current having a frequency between about 10 kHz and 100 kHz. The inverter may need to be a custom design since there may be few if any commercially available inverters designed to produce an AC signal between about 400 Hz and 1 MHz. The alternating current at the higher frequency may then be transmitted through electrical conductors 306 routed along the tool string 12. The power signal may be transmitted across tool joints to other downhole tools by way of the transmission elements 86 discussed in the description of (Prior Art)
In selected embodiments, a gear assembly may be provided between the turbine and the generator to increase the rotational speed of the generator relative to the turbine. For example, the gear assembly may be designed such that the generator rotates between about 1.5 and 10 times faster than the turbine. Such an increase in velocity may be used to increase the power generated by the generator as well as increase the frequency of the alternating current produced by the generator. One example of an axially mounted downhole generator that may be used with the present invention is described in patent application Ser. No. 11/611,310 and entitled, “System for steering a tool string,” which has common inventors with the present invention and which this specification incorporates by reference for all that it contains.
Referring now to (Prior Art)
In some embodiments the alternating electrical current may be driven at a frequency between 50 and 70 kHz. The inductive couplers 302, 1102 may each be disposed within an annular trough 404 of magnetic material. The troughs 404 may each be disposed within an annular recess 301 of the tool string components 200, 1101. At least one of the inductive couplers 302, 1102 may comprise a coil 303 that comprises a plurality of windings 601 of wire strands 602. The wire strands 602 may each be electrically isolated from each other. In some embodiments at least 85% of the energy comprised by the alternating electrical current being driven through the annular inductive coupler 302 may be inductively transferred to the adjacent inductive coupler 1102 when 160 watts are passed through the coil 303 of the inductive coupler 302. In some embodiments at least 95% of the energy may be inductively transferred when 160 watts are passed through the coil 303.
Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications apart from those shown or suggested herein, may be made within the scope and spirit of the present invention.
Number | Name | Date | Kind |
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20040104797 | Hall | Jun 2004 | A1 |
20050001738 | Hall | Jan 2005 | A1 |
20080083529 | Hall | Apr 2008 | A1 |
20160049718 | Mueller | Feb 2016 | A1 |
Number | Date | Country |
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3118803 | Jun 2020 | CA |
Number | Date | Country | |
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20220235615 A1 | Jul 2022 | US |