Evaluation of Dikili-Kaynarca Geothermal Field (NW Turkey)

Abstract

Dikili-Kaynarca geothermal field has been used since early 2000’s by five different companies with the purpose of district heating, green house heating and thermal tourism. There are over 20 wells in the field with discharge temperatures ranging from 80 to 120 °C. Encouraging discharge temperature from the wells boosted the green house investments in the field. Heavy use of geothermal water resulted with decrease in both flow rates and discharge temperatures of the wells. A comprehensive well testing and water sampling campaign was carried out to determine the possible causes of those declines in the field. Chemical analyses revealed that Dikili-Kaynarca waters are Na+K – SO4 type and meteoric in origin and a reservoir temperature range of 122-214 °C was estimated from geothermometry applications. Comparison of static and dynamic temperature measurements of two hottest wellbores within 9 years’ time span indicated a temperature drop more than 10 °C. Two of three reinjection wellbores are very close to those production wellbores showing temperature decline. In addition, at least three production wellbores were found to have casing and cementing problems. All these observations indicated that current reinjection application and wellbore failures are the main causes of the decline in the productivity of the field.