TRANSMITTER LOOPS IN SERIES FOR GEOPHYSICAL SURVEYS

摘要

The invention relates to a transmitter loop configuration used for ground and downhole electromagnetic geophysical surveys. The loop wire is spread out on the ground surface in such a way as to form several subset loops in series. Each subset loop can be juxtaposed to each other or separated by a fixed distance. The contribution of each subset to the primary electromagnetic field is improved in intensity and vector orientation so as to energize more efficiently buried geological conductors. This design generates a strong sub-horizontal primary field in an in-loop zone of the global loop. Any sub-vertical conductor buried under this in-loop zone will be maximum-coupled and will generate a secondary electromagnetic field detectable by a receiver device. This invention includes the possibility of using a combination a several pairs of loops.