Reinjection of the CO2 Into the Reservoirs of the Geothermal Waters in the Continental Rift Zones of the Menderes Massif, Western Anatolia, Turkey

Abstract

In the continental rift zones of the Menderes Massif, western Anatolia, Turkey, which were formed by extensional tectonic features, strike E-W generally and are represented by a great number of geothermal waters, epithermal mineralizations, and volcanic rocks of Middle Miocene to recent age, geothermal power plants with a capacity of up to 1,250 MWe were installed. 2.0 percent of the production of the geothermal waters in the area of the Menderes Massif displays CO2 emissions. In order to consider the geothermal waters as environmental and human friendly energy, CO2 emissions must be reinjected into the reservoirs of each geothermal waters. As alternative to inhibitors, it can be taken in consideration a reinjection of the waste CO2 quantities into the reservoir of the geothermal waters for adjust of H values of geothermal fluids. Approximately 2.0 percent of CO2 in the production of the geothermal waters is available for reinjection into the reservoirs. A small amount of this total mass might be attributed to a correction of pH value of 6-7 of geothermal fluids in a reinjection process. An acid reinjection pH value can decrease an arising oversaturation of calcite and aragonite by the pH effect of reinjected geothermal waters. However, there are difficulties. A superficial blow on of CO2 into reinjection fluid leads to push of dissolved gases in reinjection well, because high CO2 contents at high pressures can be dissolved in deeper spheres of reinjection well. Therefore, CO2 gases should be conducted to the depth below the solution depth in a separate intern pipe and must be reinjected into the reservoir of geothermal waters. However, this assumes previous condensing of CO2 gases, because die pressure in the total gas column must overstep die pressure in the mixing depth.