Geochemical Fluid Characteristics and Some Findings of Tracer Tests in the Ilan Geothermal Field, Taiwan

Abstract

Three wells drilled at a depth of about 1500 to 2800 m in metamorphic slates for National Energy Project (MOST-NEP-II), initiated in 2014, in the site of Ilan, Taiwan with the aim of establishing an Enhanced Geothermal System (EGS) power plant. To improve the understanding of well injectivity and the quality of interwell connections, a single-well tracer test was conducted at well JY-01 in 2015 and 2016 and a six-month cross-hole tracer test in 2017 between well HCL-2 and well JY-01 was carried out. Those tests are mostly experimental nature. Two separated deep flow channels were identified by both geochemical fluid characteristics and results of tracer tests. In addition, a preliminary result shows that a strong groundwater flow exists at depth 1500m and below.