Direct Subsoil Temperature Measurements at and around the Las Pailas Geothermal Project and in Rincón de la Vieja National Park, Guanacaste, Costa Rica

Abstract

Direct soil temperature measurements have been made in access holes drilled down to a maximum of 160 cm in the area that will be directly impacted by the operation of the Las Pailas Geothermal Project, as well as within the north bordering Rincón de la Vieja National Park. Each access hole is one kilometer apart and the temperature has been measured periodically at each one since June, 2008. Throughout the field area there are important differences in soil type, geological formations, elevation, and geothermal activity, all of which may influence the measured subsoil temperatures. Additionally, a soil temperature gradient was determined for each access hole by taking temperature measurements at 5, 10, 20, 50, 100 and 150 cm depth in an unlined hole. All of these data have been compiled in an Access database and integrated so that they can be visualilzed in ArcView.
This report presents the findings of this investigation thusfar and conclusions which may, along with future results, be utilized in the decision making process for future development of the Las Pailas Geothermal Field.