Geothermal exploration in the Sani-Afytos area of the Kassandra peninsula (Chalkidiki peninsula, Northern Greece)


Published: Jan 1, 2007
Keywords:
wells field low enthalpy system thermal waters resources
Ch. Kougoulis
A. Arvanitis
N. Kolios
S. Koutsinos
J. S. Kougoulis
Abstract

The Sani-Afytos area in the Kassandra Peninsula (Chalkidiki) was the area of systematic geothermal exploration. Based on deep oil borehole data, the Paleogene, Neogene and Quaternary sediments show significant thickness reaching 3600 m and cover the metamorphosed Mesozoic, mainly carbonate, basement. The detailed water temperature investigation proved the presence of sub-thermal waters (20-28°C) at depths up to 300 m and the spatial distribution of the isothermal curves at depths of 150 and 200 m according to the main NW-SE and SE-NW tectonic structures of the area. Through the construction of geothermal exploration and production wells at depths of 422-583 m, thermal waters of 31.7-36°C were detected within the Upper Miocene sediments. The average value of the geothermal gradient was calculated to be 3-4°CI 100 m. One production well of 520 m depth provides waters of 34°C while its potential flow rate is approximately 50 m /h. The geothermal waters were classified in Na-HCOi and Na-CI types of waters with TD. S 0.89-2.03 g/l. With the aid of chemical geothermometers the deep temperature was estimated to be 80-100°C. In one exploration well, the presence of gas phase (77% v/v CH4, 21.8% v/v N2) was detected. The geothermal exploration resulted in the characterization of the area as the "geothermal field of Sani-Afytos" and in the prospective development using the geothermal fluids in the tourism and other activities.

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  • Geophysics and Seismology
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References
Arnorrson, S., Gunnlaugsson, E., and Svararsson, H., 1983. The chemistry of geothermal waters in Iceland III. Chemical geothermometry in geothermal investigations, Geochim. Cosmochim. Acta, Al, 547-566.
Davis, S.N., and DeWiest, R.J.M., 1966. Hydrogeology, John Wiley & Sons, New York, 463pp.
Fournier, R.O., and Truesdell, A.H., 1973. An empirical Na-K-Ca geothermometer for natural waters, Geochimica et Cosmochimica Acta, 37, 1255-1275.
Fournier, R.O., 1981. Application of water geochemistry to geothermal exploration and reservoir engineering, In L. Rybach and L.J.P. Muffler (eds), Geothermal Systems: Principles and Case Histories, Wiley, New York, 109-143.
Giggenbach, W.F., Gonfiantini, R., Jangi, B.L., and Truesdell, A.H., 1983. Isotopie and chemical composition of Parbati Valley geothermal recharges, NW Himalaya, India, Geothermics, 12, 199-222.
Giggenbach, W.F, 1988. Geothermal solute equilibria. Derivation of Na-K-Mg-Ca geoindicators, Geochim. Cosmochimica Acta, 52,2749-2765.
Jackelen, H.-P., Loehnert, E.P., and Papakonstantinou, Α., 1986. Natural Tracers (Chemical Parameters and Environmental Isotopes) in Groundwater of the Western Chalkidiki Peninsula (Greece), Proc. of the 5th International Symposium on Underground Water Tracing, 59-73.
Kolios, N., and Kavouridis, T., 1988. The thermal situation in the area of the sedimentary basin of Thessaloniki, Proc. 3th Nat. Conference on the Renewable Energy Sources, I.S.T, 829-837.
Mountrakis, D., 1985. Geology of Greece, Thessaloniki, University Studio Press, 207pp
Mountrakis, D., Syrides, G., Polymenakos, L., and Pavlides, S., 1993. The neotectonic structure of the eastern margin of tectonic graben of Axios River - Thermaikos Gulf in the Western Chalkidiki area (C. Macedonia), Bull. Geol. Soc. Greece (Proc. of the 6th International Congress of Geological Society of Greece), Athens, XXVIII/1, 379-395.
Pavlides, S., Mountrakis, D., Kilias, Α., and Tranos, M., 1990. The role of strike-slip movements in the extensional area of Northern Aegean (Greece). A case of transtensional tectonics, Annales Tectonicae, Special issue, IV/2, 196-211.
Piper, A.M., 1944. A graphic procedure in the geochemical interpretation of water analyses, Trans. Amer. Geophysical Union, 25, 914-928.
P.P.C. (Public Petroleum Corporation) [D.E.P.-E.K.Y.], 1988. Evaluation of deep oil holes, Athens, 139pp.
Shterev, K., and Meladiotis J., 1993. Thermomineral waters and hydrogeothermal resources in the western part of the Chalkidiki Peninsula (Northern Greece), Geologica Balcanica, 23.6, Sofìa, 73-85.
Syrides, G., 1990. Lithostratigraphic, biostratigraphic and palaeogeographic study of the Neogene - Quaternary sedimentary deposits of Chalkidiki Peninsula, Macedonia, Greece, PhD Thesis, School of Geology, Aristotle Univ. of Thessaloniki, Thessaloniki, 243pp.
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