A method for transmitting signals through a metal tubular includes the
steps of transmitting modulated electromagnetic signals through a non
magnetic metal section of the metal tubular, detecting the signals or a
field associated with the signals, and controlling or monitoring devices
or operations associated with the metal tubular responsive to the
signals. A material, geometry, treatment, and alloying of the non
magnetic metal section are selected to optimize signal transmission
therethrough. A system for performing the method includes the metal
tubular and the non magnetic metal section. The system can also include a
transmitter device configured to move through the metal tubular emitting
the electromagnetic signals, an antenna on the outside of the non
magnetic metal section configured to detect the electromagnetic signals,
and a receiver-control circuit configured to generate control signals
responsive to the electromagnetic signals.