Study on Strata Affected to Electromagnetic with Drilling Measuring Signal

In order to improve the electromagnetic wave with the signal transmission distance and quantity of the drilling measuring system, with the analysis on th e transmission features of the electromagnetic wave in the strata, the paper had a study on the electric conductance rate of the rock, magnetic conductance rate, the tr ansmitting frequency of the electromagnetic wave and the length of transmitting antenna affected to the signal attenuation and transmission depth of the electromagneti C wave.The results showed that the transmission distance of the electromagnetic wave would be increased with the transmitting frequency reduced and the high electric resistance strata would be favorable for the transmission of the electromagnetic wave.When the frequency was 520 Hz and transmission distance was 1 0002 000 m, th e signal strength would be high and could meet the requirements of the engineering.The excitation antenna with the metal ring loop connected would have best effect, t he length of the metal ring should be as long as possible.When the length of the insulation section was 0.5 m, the effect of the transmitting antenna would be best.