The application results of electro-magnetic array profiling in Liupan Mountain basin
Zheng Li1, Jia Jindou1, Xu Zhiqiang2
The 5th Geological Survey Division subordinate to Bureau of Geophysical Prospecting，P．O．Box l，Gucheng，Dingxing County,Hebei Province，072656)OGP, 1998, 33(5
Abstract：Liupan Mountain basin has good petrogeologic conditions. In the exploration area，Paleogene system and upper Palaeozoic group are two sets of low-resistivity marker formations，and the low Palaeozoic and Proterozoic groups compose the high resistivity basement. This kind of electric characteristic combination offers prerequisite for studying deep electric characteristics by use of EMAP. $ channels will be used in field acquisition with the frequency of 0. 001-344Hz for receiving.In data processing，low-pass spatial filtering and correlation technique are used to suppress high-frequency static displacement and noises to enhance useful signals. 2-D finite element inversion，2-D layered medium inversion and electric interface imaging are used in data interpretation so as to respectively obtain corresponding inversion section and electric interface. In combination with geological，drilling，seismic and gravity dots，the electric data will be analysed to describe fault，basement structure，local structure and main source bed feature，thus providing the evidence basis for further exploration. As :MAP technique has many advantages (such as deeper exploring depth，no shield effect from high-resistivity layer，good sensibility to low resistivity zone，easy operation，low cost and quick returns，etc.)，this technique can counteract the weakness of seismic exploration and become a very important prospecting technique in hydrocarbon exploration of Liupan Mountain basin.
