First Geothermal Electricity Production Project from Non Artesian Geothermal Wells in Aydin-Buharkent Geothermal Field in Turkey

Abstract

Aydin-Buharkent geothermal field is located at the eastern part of Buyuk Menderes Graben and 3 km to the exisiting Kizildere-Saraykoy geothermal power plant. Two reservoir levels, one at 600-800 m level composed of marbles and cavitations and the deeper reservoir level is expected at around 2200 – 2500 m depths composed of marbles and quartzite levels in the schists. The geothermal field static water level is about 250 m depth, productivity index is about 200 tons/h/bar. Production casing dimater has been designed and applied as 13 3/8”. It is planned to install the downhole submersible pump at 450 m depth, first well maximum temperature at the well bottom is 160 °C, the flowrate has been tested as 100 L/sec. The first stage of the power plant capacity is planned as 15 MWe as binary cycle. The Buharkent geothermal brine can be classified as the diluted Kizildere geothermal brine. The CO2 gas ratio is less than 0.2 percent in the reservoir and the H2S is less than 2 ppm, this geothermal water is so suitable for power generation because of the flowrate, temperature and very less non condensable gases content. The outlet temperature at he binary cyle unit is designed as 70 °C. The reinjection is going to made without pumping with gravity flow, beacuse of the temperature difference and non artesian, non pressurized reinjection well well heads. Therefore, application of the downhole pump is beneficial for the power generation because of the production of the geothermal brine, less corrosion, less scaling and we will save energy for reinjection pumping consumption. For example at Germencik geothermal field reinjection pressure is around 30 bar. At the Paris basin reinjection pressure is around 40 bars through the sandstone reservoire. Therefore energy free reinjection is about compansate the production downhole pump energy consumption. It could be as a small difference more about 3% more in house consumtion. Therefore it could be the first application in Turkey for electricity generation at non artesianic geothermal wells. This is a kind of new approach for utilizing the non artesianic geothermal wells for electricity generation.