Inground drill string housing and method for signal coupling

Abstract

An inground housing is insertable in at least one joint of a drill string extending from a drill rig. The inground housing supports an electronics assembly for processing a data signal relating to the inground operation and a signal coupling arrangement for transferring the data signal between the electronics assembly and the drill rig by electromagnetically coupling the data signal between the signal coupling arrangement and the drill string such that the data signal is electrically conducted as an electrical data signal along at least a portion of the drill string that extends from the inground housing. In another feature, a current transformer is resiliently supported to isolate the current transformer from mechanical shock and vibration that is produced by an inground operation that is performed using the drill string. In another feature, a drill string repeater is described.

1 . In a system in which an inground tool is moved through the ground in a region for performing an inground operation, said system including a drill rig and a drill string which extends between said inground tool and said drill rig and is configured for extension and retraction from said drill rig, said drill string being made up of a plurality of electrically conductive drill pipe sections, each of which includes a section length and each of which is configured for removable attachment to the inground tool at one joint and to one another at other joints that are formed between adjacent ones of the drill pipe sections such that the drill string includes a plurality of joints to facilitate the extension and retraction of the drill string by one section length at a time, an apparatus comprising:
 an inground housing that is removably insertable at one of the joints as the drill string is extended to thereafter form part of the drill string and said inground housing defines a housing cavity that is configured for receiving an electronics assembly that processes a data signal relating to the inground operation; and   a signal coupling arrangement supported by the inground housing and configured at least for electrical communication with the electronics assembly when received in the housing cavity and for transferring the data signal between the electronics assembly in the housing cavity and the drill rig at least in part by electromagnetically coupling the data signal between the signal coupling arrangement and the drill string such that the data signal is electrically conducted as an electrical data signal along at least a portion of the drill string that extends from the inground housing and at least some of the electrically conductive drill pipe sections forming said portion of the drill string cooperate as an electrical conductor for carrying the electrical data signal.   
     
     
         2 . The apparatus of  claim 1  wherein said portion of the drill string extends at least partially from the inground housing to the drill rig such that the signal coupling arrangement couples the data signal between the signal coupling arrangement and said portion of the drill string. 
     
     
         3 . The apparatus of  claim 1  wherein said signal coupling arrangement is configured for electromagnetically receiving the electrical data signal from said portion of the drill string as the data signal and thereafter electrically transferring the data signal to the electronics assembly such that the apparatus serves as a receiver. 
     
     
         4 . The apparatus of  claim 1  wherein said signal coupling arrangement is configured for electromagnetically transferring the data signal from said electronics assembly to said portion of the drill string to produce the electrical data signal in the drill string such that the apparatus serves as a transmitter. 
     
     
         5 . The apparatus of  claim 1  wherein said signal coupling arrangement is configured for bidirectional coupling of the data signal between the electronics assembly and the drill string such that the apparatus serves as a transceiver. 
     
     
         6 . The apparatus of  claim 1  wherein said signal coupling arrangement includes a current transformer supported by the inground housing and in electrical communication with the electronics package when received in the housing cavity for electromagnetically coupling the data signal between the drill string and said current transformer. 
     
     
         7 . The apparatus of  claim 6  wherein said inground housing includes an outer surface configuration that defines an annular groove for receiving said current transformer therein. 
     
     
         8 . The apparatus of  claim 7  further comprising:
 a support arrangement for resiliently supporting said current transformer within said annular groove on said inground housing such that the current transformer is isolated at least to some extent from a mechanical shock and vibration environment to which the housing is subjected responsive to said inground operation. 
 
     
     
         9 . The apparatus of  claim 8  wherein said support arrangement includes a plurality of resilient spacers that are distributed around a peripheral configuration of the current transformer for supporting the current transformer in the annular groove and a resilient potting compound that is received in said annular groove between said resilient spacers for further supporting the current transformer in said annular recess groove to isolate the current transformer from the mechanical shock and vibration environment. 
     
     
         10 . The apparatus of  claim 8  wherein said support arrangement includes a resilient potting compound surrounding the current transformer in said annular recess groove to isolate the current transformer from the mechanical shock and vibration environment. 
     
     
         11 . The apparatus of  claim 1  wherein said electronics package includes a sensor section and the electronics package is configured for producing said data signal responsive to a sensor signal from at least one sensor in the sensor section such that the signal coupling arrangement electromagnetically couples the sensor signal onto the drill string for transfer to the drill rig using at least some of the electrically conductive drill pipe sections as said electrical conductor and said electronics package includes a locating signal antenna for electromagnetically transmitting an electromagnetic locating signal and said inground housing is configured for emanating said electromagnetic signal into the ground surrounding the inground housing. 
     
     
         12 . The apparatus of  claim 1  wherein each drill pipe section includes a box fitting at one end and a pin fitting at an opposing end and wherein said inground housing includes said box fitting at one end and said pin fitting at an opposite end. 
     
     
         13 . The apparatus of  claim 12  wherein each drill pipe section defines a through passage to provide for a flow of drilling fluid through the drill string and wherein said inground housing defines an internal passage which provides for said flow of drilling fluid through the inground housing between the box fitting and the pin fitting of the inground housing. 
     
     
         14 . The apparatus of  claim 1  wherein each drill pipe section includes a box fitting at one end and a pin fitting at an opposing end and wherein said inground housing includes said box fitting at each end and said apparatus includes a box to pin adapter that is removably attached to one of the box fittings of the inground housing to form part of said drill string. 
     
     
         15 . The apparatus of  claim 14  wherein said signal coupling arrangement is positioned nearest to a selected one of the box fittings of the inground housing and the box to pin adapter is removably attached to the other box fitting at an opposite end of the inground housing from the selected fitting. 
     
     
         16 . The apparatus of  claim 1  wherein said signal coupling arrangement includes a current transformer supported by the inground housing and in electrical communication with the electronics package when received in the housing cavity for electromagnetically coupling the data signal between the drill string and said current transformer, and the current transformer includes a winding having a first current transformer electrical lead that is electrically connected to the electronics assembly. 
     
     
         17 . The apparatus of  claim 16  wherein said winding includes a second current transformer lead that is electrically connected to the electronics package such that the first current transformer lead and the second current transformer lead are in electrical isolation from the drill string. 
     
     
         18 . The apparatus of  claim 16  wherein said electronics assembly includes a case that serves as one electrical terminal for the electronics package and inground housing is configured to cooperate with the case such that the case is electrically coupled to the inground housing and wherein said winding includes a second current transformer lead that is electrically connected to the inground housing for electrical communication with the electronics assembly. 
     
     
         19 . In a system in which an inground tool is moved through the ground in a region for performing an inground operation, said system including a drill rig and a drill string which extends between said inground tool and said drill rig and is configured for extension and retraction from said drill rig, said drill string being made up of a plurality of electrically conductive drill pipe sections, each of which includes a section length and each of which is configured for removable attachment to the inground tool at one joint and to one another at other joints that are formed between adjacent ones of the drill pipe sections such that the drill string includes a plurality of joints to facilitate the extension and retraction of the drill string by one section length at a time, a method comprising:
 arranging an inground housing for removable insertion at one of the joints as the drill string is extended to thereafter form part of the drill string and defining a housing cavity within the inground housing that is configured for receiving an electronics assembly that processes a data signal relating to the inground operation;   supporting a signal coupling arrangement using the inground housing; and   configuring said signal coupling arrangement for electrical communication with the electronics assembly, when received in the housing cavity, and for transferring the data signal between the electronics assembly in the housing cavity and the drill rig at least in part by electromagnetically coupling the data signal between the signal coupling arrangement and the drill string such that the data signal is electrically conducted as an electrical data signal along at least a first portion of the drill string that extends from the inground housing and at least some of the electrically conductive drill pipe sections forming said first portion of the drill string cooperate as an electrical conductor for carrying the electrical data signal.   
     
     
         20 . The method of  claim 19  wherein said portion of the drill string extends at least partially from the inground housing to the drill rig and the method includes electromagnetically coupling the data signal between the signal coupling arrangement and said portion of the drill string. 
     
     
         21 . The method of  claim 19  including configuring said signal coupling arrangement for electromagnetically receiving the electrical data signal from said portion of the drill string as the data signal and thereafter electrically transferring the data signal to the electronics assembly such that the electronics assembly serves as a receiver. 
     
     
         22 . The method of  claim 19  including configuring said signal coupling arrangement for electromagnetically transferring the data signal from said electronics assembly to said portion of the drill string to produce the electrical data signal in the drill string such that the electronics assembly serves as a transmitter. 
     
     
         23 . The method of  claim 19  including configuring said signal coupling arrangement for bidirectional coupling of the data signal between the electronics assembly and the drill string such that the electronics assembly serves as a transceiver. 
     
     
         24 . The method of  claim 19  including supporting a current transformer using the inground housing as part of the signal coupling arrangement and electrically connecting the current transformer in communication with the electronics package when received in the housing cavity for electromagnetically coupling the data signal between the drill string and said current transformer. 
     
     
         25 . The method of  claim 24  wherein said inground housing includes an outer surface configuration and defining an annular recess as part of the outer surface configuration and receiving said current transformer in said annular recess. 
     
     
         26 . The method of  claim 25  further comprising:
 resiliently supporting said current transformer within said annular recess on said inground housing such that the current transformer is isolated at least to some extent from a mechanical shock and vibration environment to which the inground housing is subjected responsive to said inground operation. 
 
     
     
         27 . The method of  claim 26  wherein resiliently supporting includes arranging a plurality of resilient spacers in a spaced apart, distributed way around a peripheral configuration of the current transformer for supporting the current transformer in the annular groove and applying a resilient potting compound in said annular recess between said resilient spacers for further supporting the current transformer in said annular groove to isolate the current transformer from the mechanical shock and vibration environment. 
     
     
         28 . The method of  claim 26  including applying a resilient potting compound in said wherein said support arrangement includes a resilient potting compound in said annular recess to surround the current transformer in said annular recess to isolate the current transformer from the mechanical shock and vibration environment. 
     
     
         29 . The method of  claim 19  wherein said electronics package includes a sensor section and the electronics assembly is configured for producing said data signal responsive to a sensor signal from at least one sensor in the sensor section such that the signal coupling arrangement electromagnetically couples the sensor signal onto the drill string for transfer to the drill rig using at least some of the electrically conductive drill pipe sections as said electrical conductor and said electronics assembly includes a locating signal antenna for electromagnetically transmitting an electromagnetic locating signal and including configuring said inground housing for emanating said electromagnetic locating signal into the ground surrounding the inground housing. 
     
     
         30 . The method of  claim 19  wherein each drill pipe section includes a box fitting at one end and a pin fitting at an opposing end and including configuring said inground housing to include said box fitting at one end and said pin fitting at an opposite end. 
     
     
         31 . The method of  claim 30  wherein each drill pipe section defines a through passage to provide for a flow of drilling fluid through the drill string and including configuring said inground housing to define an internal passage which provides for said flow of drilling fluid through the inground h 
     
     
         32 . The method of  claim 19  wherein each drill pipe section includes a box fitting at one end and a pin fitting at an opposing end and said method includes configuring said inground housing including said box fitting at each end and providing a box to pin adapter that is removably attachable to one of the box fittings of the inground housing to form part of said drill string. 
     
     
         33 . The method of  claim 32  including positioning said signal coupling arrangement nearest to a selected one of the box fittings of the inground housing and removably attaching the box to pin adapter to the other box fitting at an opposite end of the inground housing from the selected fitting. 
     
     
         34 . The method of  claim 19  including supporting a current transformer on said inground housing as part of said signal coupling arrangement and connecting the current transformer in electrical communication with the electronics assembly when received in the housing cavity for electromagnetically coupling the data signal between the drill string. 
     
     
         35 . The method of  claim 34  wherein said current transformer includes a winding having a first current transformer electrical lead that is electrically connected to the electronics assembly by said connecting. 
     
     
         36 . The method of  claim 35  wherein said winding includes a second current transformer lead and connecting further includes electrically connecting the second current transformer lead to the electronics assembly such that the first current transformer lead and the second current transformer lead are in electrical isolation from the drill string. 
     
     
         37 . The method of  claim 35  wherein said electronics assembly includes a case that serves as one electrical terminal for the electronics assembly and connecting includes configuring the inground housing to cooperate with the case such that the case is electrically coupled to said inground housing and wherein said winding includes a second current transformer lead and connecting includes electrically connecting the second current transformer lead to the inground housing for electrical communication with the electronics assembly. 
     
     
         38 . A repeater for use in a system in which an inground tool is moved through the ground in a region for performing an inground operation, said system including a drill rig and a drill string which extends between said inground tool and said drill rig and is configured for extension and retraction from said drill rig, said drill string being made up of a plurality of electrically conductive drill pipe sections, each of which includes a section length and each of which is configured for removable attachment to the inground tool at one joint and to one another at other joints that are formed between adjacent ones of the drill pipe sections such that the drill string includes a plurality of joints to facilitate the extension and retraction of the drill string by one section length at a time, said repeater comprising:
 an inground housing including a housing body that defines a housing cavity and said inground housing is removably insertable at any selected one of the joints as the drill string is extended to thereafter form part of the drill string and said inground housing includes a signal coupling arrangement for providing bidirectional electromagnetic coupling between the inground housing and the drill string for receiving a data signal that is carried by electrical conduction by at least some of the electrically conductive drill pipe sections making up one portion of the drill string by electromagnetically coupling the data signal from the drill string to the inground housing as a received data signal; and   a repeater electronics package received in said housing cavity of the inground housing and which is in electrical communication with the signal coupling arrangement for producing a repeater signal based on the received data signal, but which is distinguishable from the received data signal and for providing the repeater signal to the signal coupling arrangement such that the signal coupling arrangement electromagnetically couples the repeater signal back to the drill string for transfer of the repeater signal as another electrical signal along the drill string such that the repeater signal is electrically conducted by at least some of the electrically conductive drill pipe sections making up a different portion of the drill string.   
     
     
         39 . The apparatus of  claim 38  wherein said inground housing includes a current transformer in electrical communication with the inground tool for receiving the data signal and electromagnetically coupling the data signal at least onto said portion of the drill string and said coupling adapter further includes an adapter body assembly having an outer surface configuration that defines an annular recess for receiving said current transformer therein. 
     
     
         40 . A method for use in a system in which an inground tool is moved through the ground in a region for performing an inground operation, said system including a drill rig and a drill string which extends between said inground tool and said drill rig and is configured for extension and retraction from said drill rig, said drill string being made up of a plurality of electrically conductive drill pipe sections, each of which includes a section length and each of which is configured for removable attachment to the inground tool at one joint and to one another at other joints that are formed between adjacent ones of the drill pipe sections such that the drill string includes a plurality of joints to facilitate the extension and retraction of the drill string by one section length at a time, said method comprising:
 configuring an inground housing to include a housing body that defines a housing cavity and said inground housing is removably insertable at any selected one of said joints as the drill string is extended to thereafter form part of the drill string and arranging said inground housing to include a signal coupling arrangement for providing bidirectional electromagnetic coupling between the inground housing and the drill string for receiving a data signal that is carried by electrical conduction by at least some of the electrically conductive drill pipe sections making up one portion of the drill string by electromagnetically coupling the data signal from the drill string to the inground housing as a received data signal; and   supporting a repeater electronics package in said housing cavity of the inground housing in electrical communication with the signal coupling arrangement for producing a repeater signal based on the received data signal, but which is distinguishable from the received data signal and providing the repeater signal to the signal coupling arrangement such that the signal coupling arrangement electromagnetically couples the repeater signal back to the drill string for transfer of the repeater signal as another electrical signal along the drill string such that the repeater signal is electrically conducted by at least some of the electrically conductive drill pipe sections making up a different portion of the drill string.   
     
     
         41 . The method of  claim 40  including configuring the housing body of the inground housing to include a current transformer in electrical communication with the inground tool for receiving the data signal and electromagnetically coupling the data signal at least onto said portion of the drill string and further configuring the housing body to include an outer surface configuration that defines an annular recess for receiving said current transformer therein. 
     
     
         42 . In a system in which an inground tool is moved through the ground in a region during an inground operation, said system including a drill rig and a drill string which extends between said inground tool and said drill rig and is configured for extension and retraction from said drill rig, said drill string being made up of a plurality of electrically conductive drill pipe sections, each of which includes a section length and each of which is configured for removable attachment to the inground tool at one joint and to one another at other joints that are formed between adjacent ones of the drill pipe sections such that the drill string includes a plurality of joints to facilitate the extension and retraction of the drill string by one section length at a time, an apparatus comprising:
 an electronics package that is configured for inground operation;   a current transformer configured for inductively coupled communication with said drill string as part of providing for communication between said electronics package and said drill rig on said drill string by using the drill string as an electrical conductor;   a housing having a housing body that is removably insertable at one of the joints as the drill string is extended to thereafter form part of the drill string and said housing is configured at least for receiving said current transformer with the current transformer inductively coupled to the drill string and said housing defines a housing cavity for receiving said electronics package therein; and   a support arrangement for resiliently supporting said current transformer on said housing body such that the current transformer is isolated at least to some extent from a mechanical shock and vibration environment to which the housing is subjected responsive to said inground operation.   
     
     
         43 . In a system in which an inground tool is moved through the ground in a region during an inground operation, said system including a drill rig and a drill string which extends between said inground tool and said drill rig and is configured for extension and retraction from said drill rig, said drill string being made up of a plurality of electrically conductive drill pipe sections, each of which includes a section length and each of which is configured for removable attachment to the inground tool at one joint and to one another at other joints that are formed between adjacent ones of the drill pipe sections such that the drill string includes a plurality of joints to facilitate the extension and retraction of the drill string by one section length at a time, a method comprising:
 providing an electronics package that is configured for inground operation;   configuring a current transformer for inductively coupled communication with said drill string as at least part of providing for communication between said electronics package and said drill rig on said drill string by using at least a portion of the drill string as an electrical conductor;   arranging a housing having a housing body for removable insertion at one of the joints as the drill string is extended to thereafter form part of the drill string and configuring said housing at least for receiving said current transformer with the current transformer inductively coupled to the drill string and defining a housing cavity within the housing for receiving said electronics package therein; and   resiliently supporting the current transformer on said housing body for said inductive coupling to the drill string such that the current transformer is isolated at least to some extent from a mechanical shock and vibration environment to which the housing is subjected responsive to said inground operation.