Electrical Resistivity Survey of the Wairakei Geothermal Field

Abstract

Resistivity surveys of the Wairakei geothermal field were made during 1978-83 using the and multiple-source bipole-dipole techniques. The Schlunberger measurements used electrode arrays with spacings of and 1000 m, while the multiple-source bipole-dipole survey used a current transmitter placed in high resistivity ground about 6 north of the field. From the measurements, a resistivity boundary zone defining the lateral transition from to 10 to high resistivity rock at about 0.5 to km depth has been inferred. In the area of about 20 enclosed by the boundary zone, temperatures above exist in all holes penetrating deeper than 700 m. Resistivities in the eastern and northern corners of the field are lower than the average within the field.