Co2 depolama sahalarının doğal benzerlerı olarak Türkiye’deki jeotermal sistemlerin jeokimyasal karakterizasyonu.


Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Jeoloji Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2014

Tezin Dili: İngilizce

Öğrenci: Sanem Elidemir

Danışman: NİLGÜN TÜRKAN GÜLEÇ

Özet:

To mitigate the unfavourable effect of CO2 emission on global warming and climate change, geological storage of CO2 is currently regarded to be one of the major strategies. Deep saline formations constitute one of the alternative reservoirs for hosting the injected CO2 and the information about the behaviour of these reservoirs is provided via the studies of natural analogues. This thesis is concerned with the geothermal systems of Turkey as natural analogues for CO2 storage sites and the evaluation of their geochemical characteristics in terms of possible hydrogeochemical processes involved in CO2 storage. For the selected geothermal fields from western, eastern and northern Anatolia, the hydrogeochemical processes and potential trapping mechanisms controlling the systems are determined with the assistance of various geochemical approaches including the geochemical characterization of the system, speciation-solubility calculations, estimation of relative contribution of carbonate and sulphate minerals to the system, and modelling studies (such as inverse modelling, dedolomitization modelling) depending on the behaviour of the field. The results lead to the recognition of three different groups of geothermal systems with respect to the dominant trapping mechanisms: mineral trapping, solubility trapping and mineral ± solubility trapping. In some of the fields from western Anatolia, mineral trapping seems to be the major mechanism, while the others show the effects of both mineral and solubility trapping; a special mechanism named dedolomitization is also identified for Emet geothermal field. For eastern Anatolian fields, and for the fields located along the North Anatolian Fault Zone, solubility trapping is the dominant mechanism.