Crosshole resistivity survey case study 1
Crosshole resistivity survey to find water
Crosshole survey can be very effective in detecting groundwater and fracture zone. In some case, even with environmental limitation, where only a handful electrodes can be depolyed, crosshole resistiviy survey can still produce sound result. For example, in one of the survey we did, seven and fourteen electrodes were employed in the left and right boreholes respectively. With a special information acquisition arrangement, 2,500 information points were collected at intervals ten minutes. the info points were then inverted into a real impedance section.
It is apparent that a high impedance band is found within the middle of the survey space resembling a arenaceous rock layer that decreases in thickness from right to left. Core logging showed that the sandstone's higher and lower layers square measure composed of chalky lithology with high consistence and water content, so low impedance.