Response of electromagnetic-pulse logging sonde in axially symmetrical formation

The time-domain response of an electromagnetic-pulse logging sonde in axially symmetrical formations is obtained using the transmission-line-matrix (TLM) technique. The sonde consists of transmitting and receiving coils that are placed on the axis of the borehole. The formation is assumed to have horizontal layers with or without invasion zones. The transmitting coil emits an electromagnetic pulse of known shape. The receiver transient response was computed using the TLM technique, which calls for dividing the formation into small cells. Each cell is simulated with a matrix of transmission-lines which are connected to those of the adjacent cells.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>