| Title | Nature and Properties of Recently Discovered Hidden Low-Temperature Geothermal Reservoirs in Iceland |
|---|---|
| Authors | G. Axelsson, G. Bjornsson, Th. Egilson, O.G. Flovenz, B. Gautason, S. Hauksdottir, M. Olafsson, O.B. Smarason and K. Saemundsson |
| Year | 2005 |
| Conference | World Geothermal Congress |
| Keywords | Low-temperature systems, recently discovered, reservoir characteristics, case studies |
| Abstract | Low-temperature geothermal resources play a major role in the energy economy of Iceland, in particular for space-heating. The low-temperature systems are normally characterized by warm or hot springs and/or altered ground. A number of such systems have been discovered in recent years in areas devoid of these surface manifestations, many already in use for space heating in nearby towns and villages. They were all discovered after intense surface exploration, with the key to their discovery being exploration through temperature field mapping by the drilling of shallow temperature gradient wells. Because these areas are devoid of surface manifestations the question has arisen whether their nature and properties are in some ways different from those of other low-temperature systems in Iceland. The nature and properties of some of these systems have been studied on the basis of comprehensive reservoir engineering data, as well as chemical data, and the results compared with such information for other low-temperature systems in Iceland, which have surface manifestations. The purpose was to identify inherent differences between the two kinds of systems. Three of these systems are presented as examples; Hofsstadir in W-Iceland, Hjalteyri in N-Iceland and Eskifjordur in E-Iceland. The results indicate that the characteristics of these systems fall within the range observed for other systems, except perhaps for the Hofsstadir system, which appears to have abnormally closed boundaries and limited recharge, as well as different chemical characteristics. This is attributed to the tectonic setting of the field in W-Iceland. The Eskifjordur field also appears markedly different. |