Abstract:
A sealed chamber for disposal in a wired pipe segment includes a base element, electronics supported in a chamber in the base element and a sealing layer that prevents the electronics inside the chamber from harmful gases and fluids, the sealing layer comprising a reactive multi-layer foil material (RMFM).

Description:
BACKGROUND OF THE INVENTION 
       [0001]    During subterranean drilling and completion operations, a pipe or other conduit is lowered into a borehole in an earth formation during or after drilling operations. Such pipes are generally configured as multiple pipe segments to form a “string”, such as a drill string or production string. As the string is lowered into the borehole, additional pipe segments are coupled to the string by various connection mechanisms, such as threaded couplings. 
         [0002]    Various power and/or communication signals may be transmitted through the pipe segments via a “wired pipe” configuration. Such configurations include electrical, optical or other conductors extending along the length of selected pipe segments or string segments. The conductors are operably connected between pipe segments by a variety of configurations. 
         [0003]    One such configuration includes a threaded male-female configuration often referred to as a pin box connection. The pin box connection includes a male member, i.e., a “pin end” that includes an exterior threaded portion, and a female member, i.e., a “box end”, that includes an interior threaded portion and is configured to receive the pin in a threaded connection. 
         [0004]    Some wired pipe configurations include a transmission device mounted on the tip of the pin end as well as in the box end. The transmission device, or “coupler,” can transmit power, data or both to an adjacent coupler. The coupler in the pin end is typically connected via a coaxial cable or other means to the coupler in the box end. 
         [0005]    The drilling environment is harsh and exposure of some or all of electronic elements described above may result in damage to those elements. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0006]    Disclosed herein is sealed chamber for disposal in a wired pipe segment that includes a base element, electronics supported in a chamber in the base element and a sealing layer that prevents the electronics inside the chamber from harmful gases and fluids, the sealing layer comprising a reactive multi-layer foil material (RMFM). 
         [0007]    Also disclosed is an electronic frame for use in a downhole component coupling mechanism in a segmented wired pipe system. The frame includes a first frame element including at least one retaining structure configured to retain electronics; and a sealing layer forming a seal with the first frame element, the sealing layer preventing downhole elements from contacting the electronics, the sealing layer sealed to the frame by a reactive multi-layer foil material (RMFM) connection. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike: 
           [0009]      FIG. 1  depicts an exemplary embodiment of a wired pipe segment of a well drilling and/or logging system; 
           [0010]      FIG. 2  depicts an exemplary embodiment of a box connector of the segment of  FIG. 1 ; 
           [0011]      FIG. 3  depicts an exemplary embodiment of a pin connector of the segment of  FIG. 1 ; 
           [0012]      FIG. 4  is a perspective view of a sealed chamber; 
           [0013]      FIG. 5  is cut-away side view of the sealed chamber of  FIG. 4 ; 
           [0014]      FIG. 6  is a perspective view of a repeater element; and 
           [0015]      FIGS. 7A-7B  show a sealing hatch according to one embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0016]    A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of example and not limitation with reference to the Figures. 
         [0017]    Referring to  FIG. 1 , an exemplary embodiment of a portion of a well drilling, logging and/or production system  10  includes a conduit or string of drill pipe segments  14  (generally denoted as string  12 ), such as a drillstring or production string, that is configured to be disposed in a borehole for performing operations such as drilling the borehole, making measurements of properties of the borehole and/or the surrounding formation downhole, or facilitating gas or liquid production. 
         [0018]    For example, during drilling operations, drilling fluid or drilling “mud” is introduced into the string  12  from a source such as a mud tank or “pit” and is circulated under pressure through the string, for example via one or more mud pumps. The drilling fluid passes into the string and is discharged at the bottom of the borehole through an opening in a drill bit located at the downhole end of the string. The drilling fluid circulates uphole between the string and the borehole wall and is discharged into the mud tank or other location. 
         [0019]    The wired pipe segment  14  has an uphole end  18  and a downhole end  16 . As described herein, “uphole” refers to a location near the point where the drilling started relative to a reference location when the segment  14  is disposed in a borehole, and “downhole” refers to a location away from the point where the drilling started along the borehole relative to the reference location. It shall be understood that the uphole end  18  could be below the downhole end  16  without departing from the scope of the disclosure herein. In this same vein, as a plurality of segments are joined to form a string, the directions related to up and downhole described may also refer to the resultant string. 
         [0020]    At least an inner bore or other conduit  20  extends along the length of each segment  14  to allow drilling mud or other fluids to flow therethrough. A transmission line  22  is located within the inner bore  20  of segment  14 . In one embodiment, the transmission line enters the inner bore  20  via an inlet as described below. In one embodiment, the transmission line  22  is a coaxial cable. In another embodiment, the transmission line  22  is formed of any manner of carrying power or data, including, for example, a twisted pair. In the case where the transmission line  22  is a coaxial cable it may include an inner conductor surrounded by a dielectric material. The coaxial cable may also include a shield layer that surrounds the dielectric material. In one embodiment, the shield layer is electrically coupled to an outer conductor that may be formed, for example, by a rigid or semi-rigid tube of a conductive material. 
         [0021]    The segment  14  includes a downhole connection  24  and an uphole connection  26 . The segment  14  is most commonly configured so that the uphole connection  26  is positioned at an uphole location relative to the downhole connection  24 . The downhole connection  24  includes a male connection portion  28  having an exterior threaded section, and is referred to herein as a “pin end”  24 . The uphole connection  26  includes a female connection portion  30  having an interior threaded section, and is referred to herein as a “box end”  26 . 
         [0022]    The pin end  24  and the box end  26  are configured so that the pin end  24  of one wired pipe segment  14  can be disposed within the box end  26  of another wired pipe segment  14  to effect a fixed connection therebetween to connect the segment  14  with another adjacent segment  14  or other downhole component to form a drill string. In one embodiment, the exterior of the male connection portion  28  and the interior of the female connection portion  30  are tapered. Although the pin end  24  and the box end  26  are described has having threaded portions, the pin end  24  and the box end  26  may be configured to be coupled using any suitable mechanism, such as bolts or screws or an interference fit. 
         [0023]    In one embodiment, the system  10  is operably connected to a downhole or surface processing unit which may act to control various components of the system, such as drilling, logging and production components or subs. Other components include machinery to raise or lower segments  14  and operably couple segments  14 , and transmission devices. The downhole or surface processing unit may also collect and process data generated by the system  10  during drilling, production or other operations. 
         [0024]    As described herein, “drillstring” or “string” refers to any structure or carrier suitable for lowering a tool through a borehole or connecting a drill bit to the surface, and is not limited to the structure and configuration described herein. For example, a string could be configured as a drillstring, hydrocarbon production string or formation evaluation string. The term “carrier” as used herein means any device, device component, combination of devices, media and/or member that may be used to convey, house, support or otherwise facilitate the use of another device, device component, combination of devices, media and/or member. Exemplary non-limiting carriers include drill strings of the coiled tube type, of the jointed pipe type and any combination or portion thereof. Other carrier examples include casing pipes, wirelines, wireline sondes, slickline sondes, drop shots, downhole subs, BHA&#39;s and drill strings. 
         [0025]    Referring to  FIGS. 2 and 3 , the segment  14  includes at least one transmission device  34  (also referred to as a “coupler” herein) disposed therein and located at the pin end  24  and/or the box end  26 . The transmission device  34  is configured to provide communication of at least one of data and power between adjacent segments  14  when the pin end  24  and the box end  26  are engaged. The transmission device  34  may be of any suitable type, such as an inductive coil, direct electrical (e.g., galvanic) contacts and an optical connection ring. The coupler may be disposed at the inner or outer shoulder. Further, the transmission device  34  may be a resonant coupler. It shall be understood that the transmission device  34  could also be included in a repeater element disposed between adjacent segments  14  (e.g., within the box end). In such a case, the data/power is transmitted from the transmission device in one segment, into the repeater. The signal may then be passed “as is,” amplified, and/or modified in the repeater and provided to the adjacent segment  14 . 
         [0026]    Regardless of the configuration, it shall be understood that each transmission device  34  can be connected to one or more transmission lines  22 . Embodiments disclosed herein are directed to how the transmission lines  22  can be formed and disposed in a segment  14 . In one embodiment, the transmission line  22  is capable of withstanding the tensile, compression and torsional stresses and superimposed dynamic accelerations typically present in downhole tools when exploring oil, gas or geothermal wells. In one embodiment, a channel is formed in the segment  14  between the location of a portion of the transmission device  34  and the inner bore  20 . The transmission line  22  is partially contained in the inner bore  20  and the channel. In one embodiment, the channel is gun drilled into the pipe segment  14 . 
         [0027]    In one embodiment, the transmission line  22  includes a wire channel (e.g., an outer protective layer) and a transmission element. The transmission element can be selected from one of coaxial cable, twisted pair wires, and individual wires. The following description is presented with respect to coaxial wire but it shall be understood that the teachings herein are applicable to any type of transmission element. In one embodiment, tension is created in the transmission element with respect to one or both the wire channel and the body of the segment  14 . This tension may help to abate independent motion between the transmission element and the wire channel. 
         [0028]    In some cases it may be desirable to attach electronic components close to the transmission device  34 . Due to the harsh drilling environment, the electronic components need to be sealed from mud and other elements. The dimensions of the thread connection limit the space available for the design of encapsulated electronic components or connectors. In one embodiment, a reactive multi-layer foil material (RMFM) sealed connection may be used to seal such a compartment in which such electronics are sealed. An RMFM is formed of two mutually reactive metals (e.g., aluminium and nickel) formed in thin layers to create a laminated foil. Application of a heat pulse causes the aluminium and nickel to undergo self-sustaining exothermic reaction, producing an intermetallic compound nickel aluminide (NiAl) that can seal two elements together. The heat pulse may be provided by a bridge wire, a laser pulse, an electric spark, a flame, or by other means. The reaction occurs in solid and liquid phase only, without releasing any gas. Other examples of multilayer combinations include aluminium-titanium and titanium-amorphous silicon. 
         [0029]    Such a seal may be smaller than an elastomeric seal. Also, a seal based on an RMFM connection may have improved reliability due to its ability to endure high temperature and pressure conditions. In some embodiments a seal that is electrical conductive might be desirable and RMFMs may be electrically conductive in some instances. 
         [0030]    In some cases, a RMFM sealed connection requires the application of less heat than welding and may allow for connections in positions that could not be reached by a welding machine. Further, the processing time as compared to welding could be reduced and be performed without outgassing. 
         [0031]      FIG. 4  illustrates a sealed cavity  100  that may be formed by the use of an RMFM seal. The cavity  100  includes a main body  102  that includes an electronics location  104  where electronics  106  are located. The electronics  106  may be used to condition or otherwise modify a signal passing between first and second connectors  108 ,  110  that are illustrated as wires in  FIG. 4 . The electronics should be sealed from drilling mud. Thus, in one embodiment, a sleeve  112  is provided that covers the electronics  106 . In one embodiment, the sleeve  112  is sealed to the main body  102  by one or more RMFM connections. Using an RMFM connection may allow for sealing the electronics  106  without exposing them to possibly damaging welding head and may last longer than an elastomeric seal. The electronics  106  can include any type of electrical components and can be used for any number of different purposes. For instance, electronics  106  could be used, for example, in a repeater element that boosts a signal as it traverses one or more wired pipe segments. In another embodiment, the electronic  106  could be used to match the impedance of different circuits connected to first and second connectors  108 ,  110 . For instance, the electronics could match the impedance of a transmission device  34  to a transmission line  22  ( FIG. 3 ). 
         [0032]      FIG. 5  is a cut-away side view of the  FIG. 4  illustrates a sealed cavity  100  shown in  FIG. 4 . The cavity  100  is formed main body  102  with a cavity or electronics location  104  into which electronics  106  are disposed. As above, the electronics  106  may be used to condition or otherwise modify a signal passing between first and second connectors  108 ,  110 . As illustrated, the first and second connectors  108 ,  110  are electrically insulated from the main body by insulating materials  122 ,  124 , respectively. To form a seal between the sleeve  112  and the main body  102 , two RMFM connections or seals  120 ,  121  are formed. For example, the RMFM seals could be formed by disposing rings of a RMFM at the locations shown of seals  120 ,  121  and then exposing those regions to a heat pulse from one or more of: a bridge wire, a laser pulse, an electric spark, a flame, or by other means. 
         [0033]    In the preceding examples, an RMFM seal in a electronics cavity  100  has been described. It shall be understood, however, that the seal could be used in any component used in a down-hole environment. 
         [0034]    Signal repeaters have been used to enhance transmission of power and communications between components over a telemetry line or system. Such repeaters are provided to reduce signal loss during transmission of data from downhole components to the surface. 
         [0035]      FIG. 6  illustrates an embodiment of a pressure-sealed and mechanically robust electronic frame  40  configured to be disposed within a coupling assembly between downhole components, e.g., within a space formed within the pin  24  and/or the box  26 . In one embodiment, the electronic frame includes electronics configured to facilitate wired pipe telemetry or other communications. The frame is mechanically distinct and separate from the coupling assembly and the downhole components, and is configured to be secured at least axially based on encapsulation of the frame by the coupling assembly and/or the downhole components. Thus, the frame does not need to be directly sealed or adhered to the connection/components, but rather can rely upon the already existing sealing engagement between the components (e.g., the box-pin connection). 
         [0036]    As shown in  FIG. 6 , the frame  40  is configured to support electronics for drill pipes, downhole tools and other downhole components. Exemplary electronics include repeater electronics of a signal transmission system configured to transmit power and/or communications between downhole components. For example, the frame  40  includes recesses, chambers or other retaining structures to house repeater components (e.g., electronics and sealing components) for transmitting signals between components. Such exemplary repeater components include batteries  42 , control electronics  44  such as multi-chip modules (MCMs), and transmission devices  34  such as coupler rings, antennas, electrical contacts and inductive coupling elements. As above, the transmission devices may be of any suitable type, such as an inductive coil, direct electrical contacts and an optical connection ring. Other exemplary components include transmission components such as connectors  48 , interfaces  50  and various sealing components  52  such as glass seals and antenna seals. 
         [0037]    The frame  40  includes a fluid conduit  204  that allows for fluid to pass through it. In one embodiment, the transmission element  32  is sized and configured such that the fluid (e.g. drilling mud) can pass through it. 
         [0038]    According to one embodiment, the frame  40  includes an outer sealing layer  201  that seals elements in the recesses, chamber or other retaining structures of the of the frame  40 . In one embodiment, RMFM seals  201 ,  202  seal the frame and the outer sealing layer  201  to protect elements in the recesses. It shall be understood that any of the batteries, control electronics  44  or other devices carried by the frame  40  could themselves be in sealed chambers formed as described above. 
         [0039]    In the above description a full circumferential seal has been illustrated. It shall understood, and with reference now to  FIGS. 7A-7B , that a bead  704  of RMFM may be used to seal a hatch  700  over a cavity defined by the outer surface  708  of the downhole tool  710 . 
         [0040]    While the invention has been described with reference to example embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims.