System and method for downhole telemetry

A measurement while drilling (MWD) system for transmitting data from downhole in a wellbore being drilled in an earth formation to a surface station, said wellbore having a drill string, said system comprising:

• a controller module for intercepting a data signal from a directional module indicative of at least one parameter acquired from at least one sensor;
• an amplifier module for amplifying said data signal to generate an electromagnetic (EM) signal and for transmitting an EM transmit signal through said earth formation by applying said EM signal across a region of isolation in said drill string;
• and
• a surface system for receiving said EM transmit signal, measuring said EM transmit signal with respect to a reference to generate a received signal, conditioning said received signal, converting said received signal to an emulated pulse signal compatible with a pulse decoder, and transmitting said emulated pulse signal to said pulse decoder to be decoded by said pulse decoder for subsequent use.

A method for transmitting data from downhole in a wellbore being drilled in an earth formation to a surface station, said wellbore having a drill string, said method comprising:

• intercepting a data signal from a directional module indicative of at least one parameter acquired from at least one sensor;
• if instructed to operate according to pulse telemetry, directing said data signal to a pulse module to generate a pulse signal and transmitting said pulse signal through a mud column in said drill string;
• if instructed to operate according to electromagnetic (EM) telemetry, amplifying said data signal to generate an EM signal, transmitting an EM transmit signal through said earth formation by applying said EM signal across a region of isolation in said drill string;
• receiving at a surface system, either said EM transmit signal or said pulse signal according to a telemetry mode;
• if instructed to operate according to pulse telemetry, directing said pulse signal to a pulse decoder to be decoded by said pulse decoder for subsequent use;
• and
• if instructed to operate according to EM telemetry, measuring said EM transmit signal with respect to a reference to generate a received EM signal, conditioning said received EM signal, converting said received EM signal to an emulated pulse signal compatible with said pulse decoder, and transmitting said emulated pulse signal to said pulse decoder to be decoded by said pulse decoder for subsequent use.

A measurement while drilling (MWD) system for transmitting data from downhole in a wellbore being drilled in an earth formation to a surface station, said wellbore having a drill string, said system comprising:

• a transmitter for transmitting EM signals;
• a controller configured to interface with a direction module downhole to intercept a data signal from said directional module indicative of at least one parameter acquired from at least one sensor, said controller comprising a downhole multiplexer for receiving instructions for operating in either electromagnetic (EM) telemetry or pulse telemetry, wherein if instructed to operate according to pulse telemetry, directing said data signal to a pulse module to generate a pulse signal for transmitting said pulse signal through a mud column in said drill string and if instructed to operate according to EM telemetry, providing said data signal to said transmitter to amplify said data signal to generate an EM signal and transmit an EM transmit signal through said earth formation by applying said EM signal across a region of isolation in said drill string;
• and
• a surface system configured to receive either said EM transmit signal or said pulse signal according to a telemetry mode, said surface system comprising a surface multiplexer to provide to a pulse decoder, either an emulated pulse signal or said pulse signal, wherein if instructed to operate according to pulse telemetry, directing said pulse signal to said pulse decoder to be decoded by said pulse decoder for subsequent use, and if instructed to operate according to EM telemetry, measuring said EM transmit signal with respect to a reference to generate a received EM signal, conditioning said received EM signal, converting said received EM signal to said emulated pulse signal compatible with said pulse decoder, and transmitting said emulated pulse signal to said pulse decoder to be decoded by said pulse decoder for subsequent use.