| Title | Geothermal Reinjection at the Hengill Triple Junction, SW Iceland |
|---|---|
| Authors | Björn.S. Hardarson, Gunnlaugur M. Einarsson, Bjarni R. Kristjánsson , Gunnar Gunnarsson, Helga M. Helgadóttir, Hjalti Franzson, Knútur Árnason, Kristján Ágústsson and Einar Gunnlaugsson |
| Year | 2010 |
| Conference | World Geothermal Congress |
| Keywords | Iceland, Hengill, Hellisheidi, geothermal, reinjection, geothermal fluid, waste water, effluent liquid, faults, fissures, 3D modelling |
| Abstract | Reinjection of waste geothermal fluid into geothermal systems has been recognized to play a very important role in present-day reservoir management and is most often environmentally necessary. Reinjection is a complex process, firstly it is a multi-parameter method and secondly it is critical to evaluate its possible effects on production wells in the geothermal field. Reykjavik Energy has had twelve injection wells drilled for the Hellisheidi power plant which is located by the Hengill central volcano in SW Iceland. The capacity of these wells varies significantly. Eventual production of the power plant will be 303 MW of electricity, 400 MW of thermal energy and some 500 L/s of waste water which has to be disposed off. The Hengill region covers about 110 km2 and is one of the most extensive geothermal areas in Iceland. It is located at a triple junction where two active rift zones meet a seismically active transform zone. Consequently, fissures and faults are very common in the area. We believe that it is crucial to delineate this tectonic arrangement in relation to the location of injection wells, both regarding their capacity and possible effects on production wells in the field. Here we present new well data from the injection area for the Hellisheidi power plant and on the structure of fissures and faults. |