Based on the data obtained from geophysical operations the centre and north of the area under study in Damavand show that there are thick sediments resulting from the depression of the earth in this region on the stone foundation and the existence of syncline structures.
Thermal mapping of the Damavand region was carried our after the excavation of 26 shallow wells (82-100 metres) and the amount of thermal inclination and the heat current under the surface have been measured and determined. The heat fluctuation is 0.25-0.7 degrees Celsius per 10 metres. The highest thermal inclination (above 0.5 degrees Celsius per 10 metres) is in the centre of Damavand near Larijan, Nonal, and Bayjan.
A study of the chemical properties of Damavand’s springs (25 springs) show that the waters of the springs near Ask, Larijan and Bayjan are the hottest with the highest density.
Based on chemical thermographic studies, the average temperature of the geothermal reservoirs in Damavand is estimated to be 150 degrees Celsius. The authors of this paper estimate Damavand region’s thermal potential to be 5x10*25 kilo joules.
A study of the above results show that after excavating deep exploration wells to gain access to the warm water reservoirs, it will be possible to use the two orbital cycle to produce electricity needed by villages and the surrounding areas.

Maku–Khoi Region
The Maku-Khoi region is situated in northwest Iran in West Azarbaijan Province. This region has a common border with Turkey (Diagram 3). Between the Propliothecus and Quarternary periods, this region was prone to sporadic volcanic activity and this resulted in the formation of various warm water springs and andosite lava. The most important geological characteristic of the Maku-Khoi region is the presence of active faults in north Tabriz and Zarineh-Rud region which play an important role in the penetration of precipitations and running waters into geothermal reservoirs, and the creation of a lot of permeable sediments which then act as a feed for geothermal resources.
According to conducted studies, the Maku-Khoi region’s main geothermal reservoir sits on carbonate rocks from the Cretaceous era and is covered by sedimentary rocks dating back to the Upper Cretaceous era.
The chemical properties of 33 rivers in the Maku-Khoi region have been studied and 19 of them are warm water springs. The temperature of these rivers, which are mostly flow out of the fault lines, is between 15-63 degrees Celsius and their discharge rate is between 20-20,000 litres per minute. This is a sign of the existence of a geothermal energy source and the existence of lithium, nitrogen and chloride in the warm waters confirms the existence of a heat source in the region. Based on chemical thermographic studies the temperature of the geothermal reservoirs in Khoi, Siah-Cheshmeh, Zavieh and Salmas have been estimated to be between 160-250, 130-180, 120-160 and 120 degrees Celsius respectively.
Gravimetric operations have been carried out in the Maku-Khoi region in order to determine the structure of the underground reservoirs. The results attained from a mao of the Gravimetric irregularities show that there are three areas with a negative gravitational irregularity in the north of the region. This is a sign of the existence of a thick layer of low-density sediments with high porosity. This is suitable for the creation of a warm water reservoir.
Thermographic studies have been carried out in the region by the excavation of six low-depth wells (100 metres). The thermal inclination of this area is 0.5-1.2 degrees Celsius per 10 metres. The Siah-Cheshme area, which is to the north of this region, has the highest thermal inclination. Experts have estimated the Maku-Khoi region’s thermal potential to be 40x10*15 kilo joules.
Based on this information it can be concluded that two reservoirs, one in the Siah-Cheshme-Zavier region and another in the Qutur-Khoi region exist in this area. With the completion of the exploration work, the precise location of these reservoirs and the amount of their warm water reserves will be determined.

Sahand Region
The Sahand region, which stretchers for 11,000 square kilometres in the northwest of Iran, and is situated between the cities of Tabriz and Maraqe, encompasses the Sahand inactive volcano (Diagram 3). The Sahand volcano is relatively young and it was active during the Propliothecus and Quarternary periods. As far as land structure is concerned, the north of the region under study in Sahand is very active and best proof of the existence of big faults in the north of Tabriz and local small faults. Rivers run along these faults.
Precipitations and running waters infiltrate the earth through the many various cracks, gaps and faults and make their way to the shaloe underground rivers or deep geothermal reservoirs.
Based on geological studies in the Sabalan region, two geothermal reservoirs have been identified the most important of which sits on the Elika carbonate permeable and is surrounded by the Shemshak permeable (Jurassic). The other reservoir is made up of the Delichai, Lar and Tizkuh (Jurassic- Cretaceous) and the reservoir’s covering stones is the Karaj permeable.
Sahand’s warm water rivers have gathered together and every group has its own specific chemical specifications. In this region 30 warm and cold water rivers in the Azarshahr, Maraqe, Bostan-Abad, Qare-Aqaj and Guyderakh have been tested and studied.
The temperature of this region’s warm water spring can reach 24-40 degrees Celsius. Th hottest rivers are in Bostanabad (40 degrees) and Qare-Aqaj (30-35 degrees). The most salty springs are in the Guyderakh, Bostan-Abad and Liqvan regions.
Based on chemical thermographic studies, the average temperature of Sahand region’s geothermal reservoirs is 100 degrees Celsius. The hottest is in Bostan-Abad (northeast Sahand) and its temperature is estimated to be between 150-160 degrees. On the other hand, considering that there is not much H2 gas in Sahand, it can be concluded that the temperature of the region’s heat systems is less than 150 degrees Celsius.
The results of the gravimetric operations show that there are very negative irregularities and this is evidence of the existence of light and deposits in Sahand’s northern, northwestern (Liqvan), northeastern (Bostan-Abad) fringes. This increases the chances of the existence of geothermal reservoirs in these two areas. Based on studies carried out by experts, the depth of the main carbonate permeable in the Sahand region is more than 4 km. They are deeper than the areas discovered in the Sabalan, Maku-Khoi and Damavand regions. This is why there is the need to invest more in the excavation of exploration wells in that region. In addition, the geothermal reservoirs in north Sahand can reach a temperature of between 150-160 degrees Clesius. They are colder than the geothermal reservoirs in Sabalan and Maku-Khoi (240-260 degrees Celsius) and as a result, have less priority.
According to experts, the thermal potential of the Bostan-Abad and Liqvan regions is some 23x10*15 Kilo joules. As a result, the prediction is that with the development of geothermal technology in Iran, the extensive geothermal region in Sahand with be economical in terms of the direct application of this energy for the production of heat for household, chemical, agricultural and industrial consumption, or indirect application for the production of electricity.

Conclusion
According to studies and explorations conducted by the Niroo Research Centre, the southern areas of Meshkin Shahr in the Sabalan region is the best region for the excavation of the first electricity exploration well and the subsequent development of the geothermal field for the construction of Iran’s first geothermal power plant, for the following reasons:
- The existence of various warm water spring in the south of Meshkin Shahr near Sabalan’s fault line and volcano.
- The existence of Iran’s hottest warm water spring with a temperature of 83 degrees Celsius which is situated 16 km to the south of Meshkin Shahr, 2050 km above sea level.
- Based on chemical thermographic studies, the temperature of this region’s reservoirs can reach 240 degrees Celsius.
- Due to the height of the local area and the fact that Meshkin Shahr’s warm water spring are close to a heat source, the hot water’s heating system are faster and hotter.
- Based on the results of the gravimetric operations, Meshkin Shahr has the largest sedimentary fields with negative irregularities. In other words, the most widespread sedimentary sector with a low-density and high porosity are situated in the south of Meshkin Shahr.
Considering that most of Sabalan region’s thermal potential is located in this area, in continuation of its geothermal energy exploration activities, the Niroo Research Centre intends to complete its geophysical (thermographic and magnetotelluric) explorations. In order to continue exploration work, experts are implementing plans to excavate thirty 80-100 metre deep wells in order to determine the thermal inclination and the area which has the most thermal irregularities. So that magnetotelluric operations can be carried out to determine which areas have low electrical resistance and the expanse of warm water rivers. After the completion of the above mentioned explorations, the location of the first 300-metre deep well for the geothermal power plant will be indicated and excavated. Then after the excavation of two wells and the processing of their data, the geothermal power plant will be developed and built.
For centuries, the residents of deprived villages in Sabalan, which is one of the coldest regions of the country, have had a difficult time providing fuel for heating and cooking. This is whilst there is a clean, cheap and ever-lasting energy resource in their area. With the utilization of geothermal energy, a new technology will make its way to that region.

References:
1. Amir Tamjidi, “An analysis of reports, the geothermal potential and feasibility studies in Sahand, Niroo Research Centre, October 1994
2. Khosrow Khoravi, “An analysis of reports, the geothermal potential and feasibility studies in Maku-Khoi, Niroo Research Centre, October 1994
3. Manuchehr Futuhi, “An analysis of the reports, the geothermal potential and feasibility studies in Sabalan”,
4. Manuchehr Futuhi, “Geothermal energy explorations in Azarbaijan and Damavand and feasibility studies on the use of geothermal power plants in Iran”, Niroo Research Centre, October 1994
5. Hasan Kaveh “An analysis of the reports on the estimation of potentials and feasibility of geothermal energy in Damavand Niroo Research Centre, October 1994

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Create date : 19 Dec 2007 14:54

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