Patent Publication Number: US-8986028-B2

Title: Wired pipe coupler connector

Description:
BACKGROUND 
     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 coupling mechanisms, such as threaded couplings. 
     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. The conductors are operably connected between pipe segments by a variety of coupling configurations. 
     One such coupling 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” that includes an exterior threaded portion, and a female member, i.e., a “box”, that includes an interior threaded portion and is configured to receive the pin in a threaded connection. 
     Some wired pipe configurations include a transmission device mounted on the tip of the pin 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 to the coupler in the box end. 
     BRIEF DESCRIPTION 
     Disclosed herein is a wired pipe segment that includes a body extending from a box end to a pin end and a coupler located in one of the box and pin ends, the coupler including a communication element and a coupler connector in electrical communication therewith and extending away from the communication element. The segment also includes a transmission line extending away from the coupler towards the other of the box and pin end, the transmission line including an inner conductor surrounded by a dielectric material, the inner conductor extending beyond an end of the dielectric material. The segment also includes a connector that electrically connects the coupler to the transmission line, the connector including an inner conductive connection having first and second ends that are, respectively, in contact with the inner conductor and the coupler connector. 
     Also disclosed is a connector for use in connecting a communication element to a transmission line in a wired pipe segment. The connector includes an inner conductive connection having first and second curved ends, each of the first and second curved ends including a hole formed therein an insulating material surrounding the conductive connection. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike: 
         FIG. 1  depicts an exemplary embodiment of a wired pipe segment of a well drilling and/or logging system; 
         FIG. 2  depicts an exemplary embodiment of a box connector of the segment of  FIG. 1 ; 
         FIG. 3  depicts an exemplary embodiment of a pin connector of the segment of  FIG. 1 ; 
         FIG. 4  is a partial side view of a coupler connected to a transmission line via a connector according to one embodiment; 
         FIG. 5  is a cut-away side view of a transmission line disposed in an outer conductor; 
         FIG. 6  is a perspective view of a transmission line that includes a conductive cap coupled thereto; 
         FIGS. 7A-7C  illustrate the construction of one embodiment of a connector; 
         FIGS. 8A and 8B , respectively, show a perspective view of another embodiment of a connector and a cut-away side view of the connector of  FIG. 8A  surrounded by an insulating member; 
         FIG. 9  is a perspective view of another embodiment of a connector; 
         FIG. 10  is a cut-away side view of yet another embodiment of a connector; 
         FIG. 11  is a phantom view of the connector of  FIG. 10  shown connected to a transmission line; and 
         FIG. 12  illustrates another embodiment of a connector. 
     
    
    
     DETAILED DESCRIPTION 
     A detailed description of one or more embodiments of the disclosed system, apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures. 
     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  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. 
     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  12 , for example via one or more mud pumps. The drilling fluid passes into the string  12  and is discharged at the bottom of the borehole through an opening in a drill bit located at the downhole end of the string  12 . The drilling fluid circulates uphole between the string  12  and the borehole wall and is discharged into the mud tank or other location. 
     The string  12  may include at least one wired pipe segment  14  having 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. 
     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 wired segment  14  to provide protection for electrical, optical or other conductors to be disposed along the wired segment  14 . 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. 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. 
     The segment  14  includes a downhole connection  24  and an uphole connection  26 . The segment  14  is 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 coupling portion  28  having an exterior threaded section, and is referred to herein as a “pin end”  24 . The uphole connection  26  includes a female coupling portion  30  having an interior threaded section, and is referred to herein as a “box end”  26 . 
     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. In one embodiment, the exterior of the male coupling portion  28  and the interior of the female coupling 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. 
     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  10 , 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. 
     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. 
     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 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. The each of these types of couplers shall be referred to as including a communication element that allows it to communicate a signal to another 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 . 
     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 a connector that is used to connect a transmission device to a transmission line. The connection could be galvanic or capacitive, for example. The term “direct” as used with respect to a connection shall include a galvanic connection. 
     In more detail, and referring now to  FIG. 4 , a transmission device  34  is shown coupled to a transmission line  22  by a connector  100 . The illustrated transmission line  22  is a coaxial cable that includes an inner conductor  102  surrounded by a dielectric material  104 . The transmission line  22  may also include a shield layer (not shown) that could be formed, for example, by a braided metal or metal foil layer. Regardless of how formed, the shield layer may be surrounded by an insulating layer  108  and may be electrically coupled to an outer conductor  110  in one embodiment. The outer conductor  110  can be rigid or semi-rigid and is formed of metal in one embodiment. The outer conductor  110  can extend the entire length of the transmission line  22  (e.g., from one coupler  34  at one end of a drill pipe segment to another coupler  34  at another end of the drill pipe segment). As an alternative, the outer conductor  110  may only surround regions of the transmission line  22 . 
     Of course, the exact configuration of the transmission line could be varied. For instance, the inner conductor  102  could be formed by at least two electrically connected wires or a twisted pair and/or the shield layer  108  could be omitted. In one embodiment, the transmission line  22  is fixedly attached to the outer conductor  110 , for example, by welding or otherwise connecting the transmission line  22  to the outer conductor  110 . In all of the embodiments that follow it shall be assumed (if not explicitly illustrated) that the transmission line  22  is surrounded, at least at its ends, by an outer conductor and that the two are fixedly coupled to one another at least over a part of the length of the outer conductor 
     While not illustrated it shall be understood that the outer conductor  110  can be located within a gun drilled section of the walls of the segments  14  ( FIG. 1 ). In one embodiment, the outer conductor  110  is fixed within the segments. 
     It shall be understood that the distances between the pin and box end couplers  34  can vary. If a constant transmission line  22  length is used, there may be a need for an additional connector that compensates for variations of the drill pipe lengths, such as connector  100 , to electrically connect the coupler  34  to the transmission line  22 . Disclosed below are alternative connectors. Each connector embodiment is given a different reference numeral (e.g., 100, 200, 300, etc.) but shall generally be referred to a connector. All of the connectors disclosed herein can be formed in different lengths to accommodate for such segment length differences. In some cases, any of the connectors disclosed herein may itself accommodate segment length variation by having an adjustable length. This adjustment may be accomplished by including a telescoping region in any of the connectors disclosed herein. In some cases, the connector may exhibit a parasitic capacity due to its cylindrical shape and having a dielectric disposed between two charged surfaces. As will be understood, the capacitance of a particular connector depends on its length and, in some cases, this capacitance may need to be balanced by another tuned capacitor. An alternative would be to manufacture the different lengths of connectors with a constant capacitance by varying the diameter of the inner core. 
     As illustrated in  FIG. 4 , the coupler  34  includes a coupler connection  120  that extends away from the communication element  124  of the coupler  34 . A portion  120   a  of the coupler connection  120  is shown passing through and extending beyond an optional sealing region  126 . The seal region (or stack)  126  provides for seal between the coupler connection  120  and the outer conductor  110 . 
     As more clearly illustrated in  FIG. 5 , in the embodiment shown in  FIG. 4 , the transmission line  22  is formed such that the inner conductor  102  extends beyond an end of the dielectric material  104 . The inner conductor  102  may also extend through and beyond an insulating disk  150  disposed at an end of the dielectric material. In the event that the inner conductor/dielectric are fixed relative to the outer conductor  110  the insulating disk  150  can provide a solid base on to which connectors  100  can be pressed. It shall be understood that the configuration of the transmission line  22  including the insulating disk  150  can be utilized with any of the connectors described herein. 
     As illustrated in both  FIGS. 5 and 6 , a distal end of the inner conductor  102  is surrounded by a conductive cap  152 . In the illustrated embodiment, the conductive cap  152  has a non-circular cross-section. Stated differently, the conductive cap  152  may be non-cylindrical in one embodiment. In particular, the conductive cap  152  can include a rectilinear base  154 . In one embodiment, an end  156  of the conductive cap  152  also has a rectilinear shape that is similar to but smaller than the base  154 . In addition, the conductive cap  152  can include a taper region  158  connecting the end  156  to the base  154 . It shall be understood, however that the cap  152  is optional. In one embodiment, rather than include a cap, the end of the inner conductor  102  that extends beyond the dielectric could be deformed or reshaped such that it has a non-cylindrical cross section. 
       FIGS. 7A-C  illustrate the construction of one embodiment of a connector  100 . This embodiment is for use with at least the embodiment of the transmission line  22  shown in  FIGS. 4-6 . The connector  100  of this embodiment includes first and second female ends  202 ,  204  electrically coupled by a connector core  200 . The first end  202  is configured to surround and electrically mate with the portion  120   a  of the coupler connection  120  that extends beyond the seal stack ( FIG. 6 ). The second end  204  is shaped and configured such it can mate with the conductive cap  152  illustrated in  FIGS. 7 and 8 . As illustrated in  FIG. 7B , the first end  202  and the conductor  200  are covered by an insulating layer  206 . In one embodiment, the entire assembly shown in  FIG. 7B  can then be covered by a rigid, insulating outer coating  208 . In another embodiment, the insulating layer and the outer coating could be integrally formed. In one embodiment, the outer coating  208  is formed of polyether ether ketone (PEEK) or similar high strength dielectric material. Referring again to  FIG. 4 , the outer coating  208  can serve not only to electrically insulate the connector  100  from the outer conductor  110  but also to provide a solid location onto which the optional seal stack  126  may be compressed. 
     As will be understood and with reference again to  FIGS. 7A and 7B , the second end  204  can be shaped such that the conductive cap  152  is not completely surrounded by it nor does it concentrically surround the inner conductor  102 . In that regard, the second end  204  can include gaps  210 . The gaps  210  may be spaced and arranged such that at least a portion of them are filled by at least a portion of the conductive cap  152 . 
     Referring again to  FIG. 4 , the coupler  34  may be connected to the transmission line  22  in several different manners. For example, the transmission line  22  could first be disposed in a channel in a pipe segment. Such disposal could include disposing a transmission line  22  that includes a conductive cap  152  that surrounds an end of the inner conductor  102  that extends beyond an end of the dielectric material  104  and, in one embodiment, beyond the insulating disk  150  ( FIG. 5 ). According to one embodiment, a distance (d) from the insulating disk  150  to a reference location (e.g., an end  111  of the outer conductor  110 ) may be measured. The distance (d) can be used to select length of the connector  100  that is needed to electrically couple the coupler  34  to the communication electrical line inside the conduit  22 . As described briefly above, the connector  100  may have a rigid portion that is in physical contact (or other force transferring arrangement) with the transmission line  22 . The connector  100  of the desired length can then be inserted into the outer conductor  110  such that it mates with the inner conductor  102 . The coupler  34  can then be arranged such that the coupler connector  120  is forced into electrical communication with the connector  100 . This can include, for example, causing the optional seal stack  126  to compress against the connector  100 . One of ordinary skill will understand that there are several different ways to affix the coupler  34  in a pipe segment including a press fit connecting and through the use of an adhesive. 
       FIGS. 8 and 9  show two different embodiments of connectors  300  and  400 . These embodiments can include a first end  202  the same or similar to those as shown and described above. The first end  202  is, as above, shaped and configured to receive the coupler connector  120  within it and to make electrical contact therewith. The exact configuration can vary but as illustrated the first end  202  includes one or more pre-formed crimp sections  250  that can expand to receive the coupler connector  120  and then contract to ensure electrical connection to the coupler connector  120  or connector  100 . As shown in  FIG. 8B , the first end  202  includes a hollow region  252  into which the coupler connection  120  is received. 
     In the embodiment shown in  FIG. 8A , the connector  300  includes a first end  202  and a connector core  302  that extends therefrom. In this embodiment, the inner conductor  102  of the transmission line  22  is wrapped around and in electrical communication with the connector core  302 . 
     There are many manners in which the inner conductor  102  can be made to surround the connector core  302  in the manner illustrated in  FIG. 8A . For example, the inner conductor  102  could be exposed form the dielectric material and then spirally wrapped around a shaft, dowel or other implement such that the radius of the spiral is less than the radius of the connector core  302 . The connector core  302  may then be pressed into the spiral such that the spiral surrounds in the manner illustrated in  FIG. 8A . In one embodiment, the inner conductor  102  is soldered to the connector core  302 . 
     As illustrated in  FIG. 8B , in one embodiment, a casing  310  can surround an end of the transmission line  22  and some or all of the connector core  302  that includes the inner conductor  102  wrapped around it. The casing  310 , in one embodiment, can hold the connector  300  and the transmission line  22  in a fixed relationship to one another. The casing  310  can be formed of Peek in one embodiment. 
     In  FIG. 9 , another embodiment of a connector  400  includes a first end  202  and connector core  404  extending therefrom. The connector core  404  includes a recess  406  (e.g. a groove) formed in an outer side thereof. In one embodiment, the recess  406  is formed such that it is not coaxial with the other portions of the connector  400 . In one embodiment, the inner conductor  102  is brazed or otherwise fixedly attached to the connector  400  in the recess  406 . Some or all of the connector  400  and the transmission line  22  can be surrounded by a casing in the same or similar manner as described with respect to  FIG. 8B . 
       FIG. 10  illustrates another embodiment of a connector  500  in a cut-away view. While a particular embodiment of connector  500  is shown, it shall be understood that the connector  500  can be defined as having two female receiving ends, both of which receive a conductor and that are electrically coupled to one another. 
     The illustrated connector  500  of this embodiment includes an inner conductive connection  502 . This inner conductive connection  502  can be formed, for example an arcuated flat bar having receiving holes  506  formed in the curved regions  501  thereof. In one embodiment, the inner conductive connection  502  includes two curved regions  501  both of which include at least one receiving hole  506 . The inner conductive connection  502  is disposed in an insulating sheath  504  which is surrounded by a rigid outer sleeve  508 . In one embodiment, the insulating sheath  504  may be formed of a rigid material and may transmit force from a seal stack of a coupler to an outer conductor of the transmission line  22  or the transmission line itself. 
       FIG. 11  shows a phantom view of the connector  500  coupled to a transmission line  22 . The receiving hole  506   a  of one of the curved regions  501   a  receives and makes electrical contact with an exposed end of the inner conductor  102 . The other receiving hole  506   b  of the other curved region will, as will be understood by one of skill in the art, receive the coupler connection  120  ( FIG. 4 ) or a length adjusting connector of a coupler. 
     The charge transfer only takes place at the outer diameter of the inner conductor so it is not necessary to have a solid conductive core. Thus, as will be understood, the inner conductor  102  of any of the embodiments disclosed herein could be formed as either a conductive tube or a conductive wire (e.g. solid core). The advantage of having a conductive tube lies in possible reduction of weight and material. 
       FIG. 12  illustrates another embodiment of a connector  600  coupled to a transmission line  22  that includes a conductive tube  504  that forms its inner conductor. While not illustrated, the connector  600  can include a first end  202  as shown in any of the prior embodiments. As opposed to the connector  100  of  FIG. 7A , the connector  600  does not include a second end  204 . Rather, in this embodiment, the connector  600  could be formed such that it does not include the first female end  202 . Rather, in this embodiment, the connector core  610  fits into the inner diameter of the conductive tube  604 . In this embodiment, the connector core  610  is inserted into the inner diameter of the conductive tube  604  to make electrical connection between them. The insulating layers  206  and  208  can be the same as described above. 
     In support of the teachings herein, various analyses and/or analytical components may be used, including digital and/or analog systems. The system may have components such as a processor, storage media, memory, input, output, communications link (wired, wireless, pulsed mud, optical or other), user interfaces, software programs, signal processors (digital or analog) and other such components (such as resistors, capacitors, inductors and others) to provide for operation and analyses of the apparatus and methods disclosed herein in any of several manners well-appreciated in the art. It is considered that these teachings may be, but need not be, implemented in conjunction with a set of computer executable instructions stored on a computer readable medium, including memory (ROMs, RAMs), optical (CD-ROMs), or magnetic (disks, hard drives), or any other type that when executed causes a computer to implement the method of the present invention. These instructions may provide for equipment operation, control, data collection and analysis and other functions deemed relevant by a system designer, owner, user or other such personnel, in addition to the functions described in this disclosure. 
     One skilled in the art will recognize that the various components or technologies may provide certain necessary or beneficial functionality or features. Accordingly, these functions and features as may be needed in support of the appended claims and variations thereof, are recognized as being inherently included as a part of the teachings herein and a part of the invention disclosed. 
     While the invention has been described with reference to exemplary 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 will be appreciated by those skilled in the art to adapt a particular instrument, 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 embodiment 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 appended claims.