Characterization of Kızılcahamam geothermal field by tracer testing


Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Petrol ve Doğal Gaz Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2005

Öğrenci: TEVFİK KAYA

Eş Danışman: SERHAT AKIN, MAHMUT PARLAKTUNA

Özet:

Kızılcahamam Geothermal Field which is 70 km far from Ankara, has been utilized for Geothermal District Heating System, 25 MWt, 2500 residences capacity, greenhouses heating, thermal facilities since 1994. The average production rate is 350m3/h during the heating season , 150m3/h during the summer season for hot water and yearly average reinjection rate is 114m3/h from the field. The long term projections has been studied concerning on expected pressure decline by matching 10 years field history data which contain dynamic level and temperature data. The pressure decline is 140 kPa in the field between 1999 and 2005 with the existing reinjection rate, if the existing rates do not change, the additional pressure decline which is 120 kPa will be occurred up to 2011. In order to get more information from the field, the fluorescein as tracer has been injected in to the MTA-1, and the samples were collected from the MTA-2, Fethi Bey, IHL-1 and IHL-3 for 3 months. The fluorescein concentration has been detected by using fluorimeter, and tracer concentration time plots were analyzed. The fluoreiscein was detected in short breakthrough time in MTA-2 and Fethi Bey which are close to reinjection well, breakthrough time is longer in IHL-1 and IHL-3. The interpretation of tracer test shows that there is communication between all wells. Tracer concentration time plots were compared with different mathematical models, the best match was obtained with multi-fractured model. These results show that Kızılcahamam field is not homogeneous field. It is expected that increasing the reinjection rate will decrease the pressure decline in the field.