Scientific progress on the Fenton Hill HDR project since 1983

The New Energy and Industrial Technology Development Organ! ization "NEDO# drilled well WD!0a between 0883 and 0884 in the Kakkonda geothermal _eld as part of their {{Deep Seated Geothermal Resources Survey|| project[ High!temperature measurements were carried out in WD!0a[ Logging temperatures above 303>C were con_rmed at 2599mand 2589mdepth after 71 h standing time[ Simple Horner extrapolations based on observed temperatures up to 71 h after shut!in suggested a temperature of about 499>C at 2499m depth[ Temperatures between 499>C and 409>C were also con_rmed at 2619m depth after 018 048 h standing time\ using calibrated melting tablets[ These are the highest temperatures measured in a geothermal well[ These results suggest a thermal structure consisting of three layers[ Layer one is a shallow permeable zone of the reservoir\ at less than 0499m depth\ at 129>C to 159>C[ The second layer is a deep zone of the reservoir\ which is less permeable and has a tem! perature of 249>C to 259>C from 0499m to about 2099m depth[ The third layer is a zone of heat conduction[ The transition between the hydrothermal! convection zone and the deeper heat!conduction zone is at 2099m depth in well WD!0a[ 0887 CNR[ Published by Elsevier Science Ltd[ All ri`hts reserved