PURPOSE: To increase a receiving sensitivity on a ground and to improve S/N by making an electric field into a medium, propagating a circuit formed by an electric conductor to bury the electric field into the ground, a connecting intermediate to connect it and a conductor to link respective connecting intermediates and transmitting a signal from the underground.
CONSTITUTION: A measuring signal obtained by a measuring instrument 80 for logging housed in a tip-most drill pipe 40 is propagated to an amplifier 11 by the circuit formed with plural drill pipes 4, 4 ... located at the upper side from a drill pipe 4 to house a transmitting part 90, joints 70, 70 ..., conductors 71, 71 ... and contact members 72, 72 .... The signal is fetched, amplified to the amplifier 11 and given to a suitable signal processing circuit. Thus, by detecting the change of the electric field fetched and amplified by the amplifier 11, namely, an electric signal, various data measured by the measuring instrument 80 for logging can be obtained on the ground in the bottom hole of an oil well 3.
INOUE SATORU
MAEKAWA TAKAAKI
MURAI YUTAKA
| JPS54134001A | 1979-10-18 |