| Title | Assessment of the Hofsstadir Geothermal Field, W-Iceland, by Lumped Parameter Modelling, Monte Carlo Simulation and Tracer Test Analysis |
|---|---|
| Authors | Guo Gaoxuan, Gudni Axelsson, Ye Chao and Xin Baodong |
| Year | 2010 |
| Conference | World Geothermal Congress |
| Keywords | Assessment, Hofsstadir Geothermal Field, Lumped Parameter Modelling, Tracer Test |
| Abstract | The Hofsstadir geothermal system is a typical liquid-dominated convection low temperature system, in West Iceland. The entire monitoring data, including 5 months initial well testing, collected in the single production well HO-01 during the past nearly 11 years, were simulated both by an open and closed version of lumped-parameter modeling. Reinjection started in early 2007 by injecting the return water from the heating system into injection well HO-02. Through simulating various scenarios of production schemes using the best fitting parameter model, the connections between the two wells were studied. The future water-level changes in the production well were predicted based on the assumption that a given percentage of the reinjected water can be re-extracted through the production well eventually. The calculated results indicate that this system will be able to sustain a stable 20 l/s production through 2032 without reinjection. The data of a tracer test were interpreted using a multiple flow-channel model. The results show that there are direct paths between the feed-zones of well HO-02 and that of well HO-01. A future cooling effect due to long term injection within this field was predicted using the same model. The Monte Carlo simulation results predicted with 90% probability that at least 25 MW can be produced for a period of 30 years, at least 12 MW for 60 years and at least 7 MW for 100 years. Finally, the energy increase due to the injected water was calculated for the future 30 years, using different assumption for flow channel modes. The results show that large-scale cooling is not likely to happen in this field. The injection conditions within this field are optimal and the contribution of reinjection to maintaining the reservoir pressure is quite significant. |