Reliability for Electromagnetic Data Telemetry for Downhole Application on Well Drilling Operations

Abstract

A tool and associated methods for transmitting electromagnetic data telemetry from a downhole sensor during drilling operations. The tool may include a pressure housing, the pressure housing including an EM transmitter, receiver, or transceiver. A conductive element electrically coupled to the EM transmitter, receiver, or transceiver is positioned between an upper and a lower signal conductor positioned coaxially around the conductive element. The upper and lower signal conductors support the pressure housing and conductive element within the inner diameter of a drill collar and provide electrical connection between the conductive element and a section of the drill collar on either side of an insulated gap. In some embodiments, the conductive element is tensioned between the upper and lower signal conductors.

1 . A tool for transmitting electromagnetic data telemetry from a downhole sensor during drilling operations comprising;
 a pressure housing, the pressure housing including an EM transmitter, receiver, or transceiver;   a conductive element electrically coupled to the EM transmitter, receiver, or transceiver;   a lower signal conductor positioned coaxially around the conductive element, the lower signal conductor supporting the pressure housing and conductive element within the inner diameter of a drill collar and providing electrical connection between the conductive element and a section of the drill collar on one side of an insulated gap; and   an upper signal conductor positioned coaxially around the conductive element, the upper conductor supporting the conductive element within the inner diameter of the drill collar and providing electrical connection between the conductive element and a section of the drill collar on the other side of the insulated gap.   
     
     
         2 . The tool of  claim 1  wherein the conductive element is surrounded by one or more nonconductive sleeves. 
     
     
         3 . The tool of  claim 1  wherein the conductive element is supported along its length by one or more centralizers. 
     
     
         4 . The tool of  claim 3  wherein the centralizers are formed from a rigid material. 
     
     
         5 . The tool of  claim 3 , wherein the conductive element is supported every 18 inches along its length. 
     
     
         6 . The tool of  claim 2  wherein the non-conductive sleeve is sealed at the ends against the conductive element to prevent contaminants entering between the sleeve and the conductive element. 
     
     
         7 . The tool of  claim 3  wherein the centralizer is sealed at the ends against the conductive element to prevent contaminants entering between the centralizer and the conductive element. 
     
     
         8 . The tool of  claim 1  wherein the upper and lower conductors are rigid cylindrical conductors with a plurality of through openings allowing fluid passage through the drill collar around the transmission assembly. 
     
     
         9 . The tool of  claim 1  wherein the length of the conductive element is less than 36 inches in length. 
     
     
         10 . The tool of  claim 1  wherein the upper and lower conductors are fixed at specific distances within the drill collar, and at least a portion of the conductive element is tensioned between the upper and lower signal conductors within the drill collar. 
     
     
         11 . The tool of  claim 2  wherein the upper and lower conductors are fixed at specific distances within the drill collar, and a portion of the nonconductive sleeve is compressed between the upper and lower conductors within the drill collar. 
     
     
         12 . The tool of  claim 10 , wherein the upper signal conductor and lower signal conductor comprise upper and lower hangers positioned to transfer tension from the conductive element into the drill collar. 
     
     
         13 . The tool of  claim 10 , wherein the upper and lower signal conductors further comprise toroidal contact springs to electrically couple the transmission assembly and the drill collar. 
     
     
         14 . The tool of  claim 1  wherein the electrical connections between the signal conductors and the drill collar comprise one or more toroidal springs seated around the outer diameter of the signal conductor and compressed against the inner diameter of the drill collar. 
     
     
         15 . The tool of  claim 14  wherein the signal conductor further comprises one or more seals seated around the outer diameter of the signal conductor and compressed against the inner diameter of the drill collar, said seals positioned nearer the end of the signal conductor than the toroidal springs. 
     
     
         16 . A tool for transmitting electromagnetic data telemetry from a downhole sensor during drilling operations comprising;
 a drill collar, the drill collar including a first and second tubular, the first and second tubulars formed from an electrically conductive material and coupled by an insulated gap;   a pressure housing, the pressure housing including an EM transmitter, receiver, or transceiver;   a conductive element electrically coupled to the EM transmitter, receiver, or transceiver;   a lower hanger rigidly coupled to the first tubular, the lower hanger positioned coaxially around the conductive element, the lower hanger supporting the pressure housing and conductive element within the inner diameter of the first tubular and providing electrical connection between the conductive element and the first tubular; and   an upper hanger rigidly coupled to the second tubular, the upper hanger positioned coaxially around the conductive element, the upper hanger supporting the conductive element within the inner diameter of the second tubular and providing electrical connection between the conductive element and the second tubular.   
     
     
         17 . The tool of  claim 16 , wherein the conductive element is tensioned between the upper and lower hangers. 
     
     
         18 . The tool of  claim 17 , further comprising an insulating sheath positioned around the conductive element, the insulating sheath extending between the upper and lower hanger so that the upper and lower hanger exert a compressive force on the insulating sheath as the conductive element is tensioned. 
     
     
         19 . The tool of  claim 16 , wherein the upper and lower hangers further comprise toroidal contact springs to electrically couple the transmission assembly and the drill collar. 
     
     
         20 . The tool of  claim 16  wherein the conductive element is supported along its length by one or more centralizers. 
     
     
         21 . The tool of  claim 20  wherein the centralizers are formed from a rigid material. 
     
     
         22 . The tool of  claim 20  wherein the centralizer is sealed at the ends against the conductive element to prevent contaminants entering between the centralizer and the conductive element. 
     
     
         23 . The tool of  claim 18 , wherein the insulating sheath is sealed at the ends against the conductive element to prevent contaminants entering between the sheath and the conductive element. 
     
     
         24 . The tool of  claim 16  wherein the upper and lower hangers include a plurality of through openings allowing fluid passage through the drill collar around conductive element. 
     
     
         25 . A tool for transmitting electromagnetic data telemetry from a downhole sensor during drilling operations comprising;
 a drill collar, the drill collar including a first and second tubular, the first and second tubulars formed from an electrically conductive material and coupled by an insulated gap;   a pressure housing, the pressure housing including an EM transmitter, receiver, or transceiver;   a conductive element electrically coupled to the EM transmitter, receiver, or transceiver;   a lower hanger rigidly coupled to the first tubular, the lower hanger positioned coaxially around the conductive element, the lower hanger supporting the pressure housing and conductive element within the inner diameter of the first tubular and providing electrical connection between the conductive element and the first tubular; and   an upper signal conductor, the upper signal conductor positioned coaxially around the conductive element, the upper signal conductor providing electrical connection between the conductive element and the second tubular.   
     
     
         26 . The tool of  claim 25 , further comprising an insulating sheath positioned around the conductive element, the insulating sheath extending between the upper signal conductor and the lower hanger, the insulating sheath being under compressive load between the upper signal conductor and the lower hanger so that the conductive element is under tension. 
     
     
         27 . The tool of  claim 25 , wherein the lower hanger further comprises a toroidal contact spring to electrically couple the transmission assembly and the drill collar. 
     
     
         28 . The tool of  claim 25  wherein the conductive element is supported along its length by one or more centralizers. 
     
     
         29 . The tool of  claim 28  wherein the centralizers are formed from a rigid material. 
     
     
         30 . The tool of  claim 28  wherein the centralizer is sealed at the ends against the conductive element to prevent contaminants entering between the centralizer and the conductive element. 
     
     
         31 . The tool of  claim 25 , wherein the insulating sheath is sealed at the ends against the conductive element to prevent contaminants entering between the sheath and the conductive element. 
     
     
         32 . The tool of  claim 25 , wherein the upper signal conductor comprises at least one of a bow spring, wire, or bolt. 
     
     
         33 . A method for providing improved reliability of electromagnetic (EM) data telemetry to the well site surface from downhole EM sensors in a tool assembly during drilling of a well, the method comprising:
 providing a pressure housing, the pressure housing including an EM transmitter, receiver, or transceiver;   electrically coupling a conductive element to the EM transmitter, receiver, or transceiver;   tensioning the conductive element between an upper hanger and a lower hanger, the upper hanger and lower hanger positioned within a drill collar, the drill collar including a first and second conductive tubular, the tubulars separated by an insulating gap.   
     
     
         34 . The method of  claim 33 , further comprising: selecting the diameter, length, and tension of the conductive element so that the resonant frequency is increased. 
     
     
         35 . The method of  claim 33 , wherein the upper and lower signal conductors further comprise toroidal contact springs to electrically couple the transmission assembly and the drill collar. 
     
     
         36 . The method of  claim 33 , wherein the tool is assembled prior to delivery to the rig floor at the well site. 
     
     
         37 . The method of  claim 33 , wherein the tool is shipped to the well site in a substantially assembled configuration.