Capacity Assessment of the Reservoir, Hofsstadir Geothermal Field W-Iceland

Abstract

The Hofsstadir low-temperature geothermal system is modeled with a lumped parameter model to obtain information on the properties of the system as well as to predict its pressure response to hot water production needed to sustain the Stykkisholmur district heating system. The model shows continuous water-level draw-down since production started in 1997. Proper countermeasures have to be taken by the developer to avoid overexploitation and technical problems, such as maintaining continuous injection during long-term use and lowering the pump in the production well. Connections between injection and production well are being investigated by a tracer test, which is currently ongoing. The data from the test have been analyzed by simple model, which in turn can be used to predict the effects of long-term injection.