Temperature
field study of fractured hydrothermal reservoirs in SE Bulgaria (Bourgas basin)
Klara
Bojadgieva(1), Vladimir Hristov(1), Bozhidar Srebrov(2)
(1)Geological
Institute, Bulgarian Academy of Sciences, Acad.G.Bonchev bl. 24, 1113 Sofia
(2)Geophysical
Institute, Bulgarian Academy of Sciences, Acad.G.Bonchev bl. 3, 1113 Sofia
(Received
16 January 2006; accepted 14 February 2007)
Abstract:
Fractured type hydrothermal reservoirs are not well
studied in Bulgaria compared to porous ones in terms of hydrogeological
parameters and structure of the water permeable zones. The subject of this study
are three thermal water reservoirs located in the region of SE Bulgaria (Bourgas
basin) – Poljanovo, Aitos and Sadievo. A summary of the existed geological and
hydrogeological data for the three reservoirs is done and their major
characteristics – water temperature, flow rate, temperature-depth profiles
measured in the wells and thermal capacity of the reservoirs are discussed. Maps
of temperature distribution at three depth levels below the surface – 50m,
100m and 200 m have been drawn up. They are analyzed together with another two
maps - of water temperature measured at the wellhead and calculated maximum
reservoirs temperature based on geochemical thermometers.
Zones of high temperature anomalies have been traced in depth and a sub
vertical water movement to the surface has been confirmed. The existed thermal
water application in the three reservoirs is also discussed.