GEOTHERMAL DRILLING ACTIVITY IN THE AKROPOTAMOS AREA (MACEDONIA, NORTHERN GREECE)

Résumé

The Akropotamos area constitutes a new geothermal field located in the eastern coastal zone of the Strymonikos Gulf in Macedonia (Northern Greece). After a detailed and systematic reconnaissance study including water temperature measurements at the heads of the existing irrigation and water supply wells, 6 new geothermal wells were constructed. This geothermal drilling program was performed by the Institute of Geology and Mineral Exploration during October 2003 - February 2006. Temperature and fluid conductivity logs were carried out into these boreholes during their drilling and after their completion. Well AKR-1 has a depth of 275 m and produces thermal waters at a temperature of 83o C with artesian flow rate 150 m3 /h and large amounts of dissolved CO2. Well AKR- 2 of 410 m yields 25 m3 /h of waters at 46o C. Well AKR-3 was drilled down to 515 m and the temperature of 88.9o C was measured at 498 m. This well yields about 200 m3 /h CO2-rich geothermal fluids at a temperature of 90o C with artesian flow. Next to this borehole, well AKR-4 was drilled at 180 m penetrating a shallow aquifer with waters reaching 49.7o C. During pumping test with constant flow rate, this well yielded 40 m3 /h water of 48o C. Well AKR-5, 422 deep, was drilled in the western part of the study area close to the Strymon river’s mouth. The temperature of 27.8o C was recorded at 280 m into this borehole. The last well AKR-6 was drilled down to 545 m in the eastern part of the field. The temperature of 38o C was recorded at depth of 503 m. Pumping tests were performed in wells AKR-2 and AKR-4. This geothermal drilling project has resulted in the official characterization of the Akropotamos - Kavala area as a “proven low enthalpy geothermal field”.