Thermoluminescence Techniques for Geothermal Exploration and Reservoir Evaluation

Abstract

Thermoluminescence (TL) phenomena of minerals was affected by natural annealing which was caused by geothermal activity and hydrothermal alteration. We applied TL of mineral to geothermal exploration. Quartz is usually used as a mineral for TL dating because of stability of crystal structure and impurity in crystal, and also TL of quartz is good indicator to evaluate thermal effect of geothermal activity. We applied TL of quartz in siliceous pyroclastics and intrusive rock (Tsuchiya et al., 2000, Geothermics) for evaluation of geothermal activities, however andesite and basaltic rocks are widely distributed in geothermal field, and sometimes it is very hard to separate quartz and feldspar in hydrothermal altered rocks even though they have both of quartz and feldspar. We will present some case studies for applying TL geothermal exploration by using quartz and feldspar in Japan and other countries. Couples with kinetic equation of TL of quartz and heat transfer in geothermal reservoir, we could propose novel methodology for geothermal reservoir evaluation. We estimate reservoir life time, potential and evaluation of sustainable development by TL techniques.