CONCEPTUAL MODEL OF KHORHE GEOTHERMAL RESERVOIR

Mahallat geothermal region (MGR) is one of the promising geothermal regions in Iran which has been selected for further studies almost 10 years ago. This very large region has 51,000 sqkm area and is included some parts of Qom, Markazi and Isfahan provinces.

Due to its large size, it was not possible to conduct a systematic geothermal exploration survey. So, in order to assessing of geothermal resources in MGR available data such as geological, remote sensing, water wells temperature, warm springs and aeromagnetic information were used to recognize the most favorable geothermal areas in MGR.

One of the promising geothermal areas in MGR is Khorhe area. It is located in north-east of Mahallat city. According to the available data the first conceptual model of Khorhe geothermal field was produced. Therefore, probable heat source is a large intrusive body which is positioned in the deeper parts of the area. It is believed that Permian formations (mostly carbonates) can play role as reservoir rock and Shemshak formation (Jurassic) which is composed of shale and sandstone can cover the reservoir rocks.

At the south-west of Khorhe field there is a band of Precambrian- Permian carbonate rocks which its width is 4.5 km. Meteoritic waters can penetrate these rocks and transfer toward the geothermal resource. Based on the geothermometery calculations Khorhe geothermal reservoir approximate temperature and its estimated stored thermal energy are 95 °C and 50.1 × 10⁷ KJ respectively.