The temperature distribution in the Seltjarnarnes field, SW-Iceland; The reservoir temperature in the Podhale field, S-Poland

Abstract

The report presents the temperature variation within two geothermal fields: Seltjarnarnes in SW-Iceland and Podhale in S-Poland. This study is based on the interpretation of temperature measurements in geothermal wells. For the Seltjarnarnes field the temperature logs performed in eleven boreholes during 29 years of drilling and exploitation were interpreted. The thermal gradient and formation temperature distribution within the field is given as well as the location of the main feedpoints and aquifers. No cooling was observed in the wells during the whole production period. However, the increasing salinity of the produced fluid due to seawater infiltration into the shallower aquifer suggests a possible temperature decrease of the produced fluid with time. Furthermore, the up-to date results of the temperature logs in the next production well, drilled in June-Oct. 1994 are presented. They contributed to further understanding of the field, allowing a more exact delineation of the thermal anomaly, which seems to have a very limited extent. For the Podhale field the results of the temperature simulation within the main reservoir and the predicting of the future wellhead temperature are presented, based mainly on the four years monitoring of the geothermal doublet operating in this field. Some conclusions concerning temperature distribution within the field are given. Generally, the reservoir and formation temperatures are supposed to be slightly higher than was assumed before, which is important for the planning and exploitation of the next geothermal plants.