NEW APPROACHES ON THE INVESTIGATION OF COVERED GEOTHERMAL FIELDS: EXPLORATION OF KÜTAHYA ? ŞAPHANE ? KARACADERBENT BURIED GEOTHERMAL FIELDS AND THEIR DEVELOPMENTS

The basement in Şaphane region is constituted by Paleozoic gneiss, schist and marbles belonging to northern margin of the Menderes Massif. These basement rocks are overlain by Cretaceous aged Dağardı ophiolitic melange. All these rocks are discordantly covered by Neogene ? Quaternary sedimentary and volcanic rocks deposited under lacustrine ? continental environments. The main purpose of this study is to explore buried geothermal system on a covered area using geological, geophysical and geochemical methods and to develop this system by drilling investigations. Geological, geophysical, geochemical and drilling investigations, well development and test studies were applied in this research. This study is a typical example for geothermal researches carried out in covered areas. Thus, a new approach was aimed to be brought out in such investigations. Especially; the profiling was applied, and geological structures and geochemical data were used for the selection of profiles at geophysical investigations instead of gridding which had typically been used for many years. The geothermal system was handled in regional scale rather than local scale with this study. As a result of research assessments, a drill location was selected on a totally covered area where there was no surface data around Şaphane Karacaderbent. At drilling number KŞÜ-3, a reservoir temperature of 181,2ºC were reached at a depth of 2500 m. From the well which its development and test studies had been completed at 10 psi at wellhead pressure (WHP), vapor + water production was obtained at a temperature of 114ºC and a flow rate of 25 I/s in case of artesian. As for the production tests carried out by compressor at 22 PSİ well head pressure (WHP), vapor + water was obtained at a temperature of 112ºC and a flow rate of 35 l/s. The fluid obtained from the well is suitable for the production of electricity and for heating of houses and greenhouses due to the production values revealed at the end of temperature and tests. When turbine rejection heat is taken as 75ºC, the apparent potential of electrical energy in the well is 21,3 MWt and owns a potential to heat 1300 houses or an area of 85000 m2 for greenhouses.