GEOTHERMAL EXPLORATION IN THE ALEXANDRIA AREA, THESSALONIKI BASIN (MACEDONIA, NORTHERN GREECE)


A. Arvanitis
N. Kolios
D. Ntokos
Résumé

The area of Alexandria is located in the Thessaloniki basin that has been filled with more than 4 km of sediments. In 1980, oil exploration borehole AL-1, 1,705 m deep, was drilled north of the town of Alexandria and the temperatures of 39 and 65oC were recorded at depths of 700 and 1,705 m respectively. During 1996-2000, two geothermal exploration boreholes were drilled at depths of 532 and 620 m penetrating Quaternary and Pliocene sediments and the temperatures of 30.1 and 33.4oC were measured at 500 and 611 m respectively. The preliminary geothermal investigation resulted in the construction of the first production well (GN-1P). It was drilled to a depth of 805 m penetrating clays, sands, tuffs, marls, clayey marls, marly limestones, gravels, sandstones and conglomerates. The borehole was cased down to 805 m and screens were placed at various depths below 607 m. Temperature and electrical conductivity values of 35.1-37.2oC and 5,100-8,200 μS/cm respectively were recorded at depths of 607-800 m. This well discharges 30-40 m3/h waters at 34.1oC with artesian flow and provides 130 m3/h waters at 35.5oC with pumping. The produced geothermal water with TDS of 2.18 g/l belongs to the Na-Cl type differentiated from the shallow waters. The thermal capacity of well GN-1P is calculated to be 1.65 MWt.

Article Details
  • Rubrique
  • Engineering Geology, Hydrogeology, Urban Geology
Téléchargements
Les données relatives au téléchargement ne sont pas encore disponibles.
Références
Alexiadis, Ch., 1988. Petroleum geological study of the Katerini-Thessaloniki basin, Report, PPC,
Athens, 40 pp. (in greek).
Arnorrson, S., Gunnlaugsson, E. and Svavarsson, H. 1983. The chemistry of geothermal waters in
Iceland III. Chemical geothermometry in geothermal investigations, Geochim. Cosmochim.
Acta, 47, 567-577.
Atzemoglou, A., Karydakis, G., Kolios, N. and Koutsinos, S., 2000. Geothermal exploration in the
western Thessaloniki basin, Report, IGME, Thessaloniki, 17 pp. (in greek).
BEICIP, 1980. Exploration Pétrolière en Grèce Orientale, Recherches Géophysique Onshore Basin
de Thessalonique, Internal Report for Public Petroleum Corporation.
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: Rybach, L. and Muffler, L.J.P., eds., Geothermal Systems: Principles and
Case Histories, 109-143, New York, Wiley.
Giggenbach, W.F., Gonfiantini, R., Jangli, B.L. and Truesdell, A.H., 1983. Isotopic and chemical
composition of Parbati Valley geothermal recharges, NW Himalaya, India, Geothermics, 12,
-222.
Giggenbach, W.F., 1988. Geothermal solute equilibria. Derivation of Na-K-Mg-Ca geoindicators,
Geochim. Cosmochimica Acta, 52, 2749-2765.
Institute of Geology and Mineral Exploration (IGME), 1983. Geological Map of Greece, Scale
:500,000, Athens.
Kolios, N., Koutsinos, S., Kougoulis, C., Arvanitis, A. and Karydakis, G., 2005. Exploration and
identification of geothermal fields in the Thessaloniki basin, Report, IGME, Thessaloniki, 3-
(in greek).
Lalechos, N., 1986. Correlations and observations in molassic sediments in onshore and offshore
areas of North Greece, Mineral Wealth, 42, 7-34.
P.P.C. (Public Petroleum Corporation), 1988. Inventory of low enthalpy geothermal resources disc
overed through deep oil and gas exploration wells, Athens, 54-77.
Piper, A.M., 1944. A graphic procedure in the geochemical interpretation of water analysis, Tran
s. Amer. Geophysical Union, 25, 914-928.
S.P.E.G. (Societé de Prospection et d’ Etudes Géotherrmiques), 1982. Evaluation du potential
géothermique des bassins Tertaire du Nord de le Grèce, Annexes.
Tzimourtas, S., 1991. Hydrogeological study of the Axios basin, Report, IGME, 85 pp. (in greek).
Articles les plus lus par le même auteur ou la même autrice