| Abstract |
The City of Xianyang is rich in low-temperature geothermal resources embedded in the Guanzhong basin underneath the City. The reservoir rocks are mostly sandstone layers, but major faults play a key role in the geothermal activity. Close to 30 wells, ranging in depth from 1500 to 3500 m, have been drilled in the area and production temperature is usually between 70 and 120 °C. Geothermal utilization in Xianyang has been growing rapidly in the last 10 – 15 years. With a rather high housing density (0.5 to 1.5 m² floor space per m² of land) Xianyang is well suited for district heating application. A Joint Venture company between Iceland and China started developing geothermal space heating systems in Xanyang in the year 2003 and has now (2009) installed geothermal heating in over 1,200,000 m² of housing. The aim is to introduce geothermal heating in over 50% of the City in the next 10 years or around 8,000,000 m² of housing, thus becoming by far the largest geothermal space heating system in China. An initial resource assessment conducted in 2005, based on rather scarce data, shows that the Xianyang geothermal system should be able to sustain the utilization planned. In order for this to be possible several resource management issues must be addressed and solved. These include: almost full reinjection, comprehensive monitoring of all wells in the area, regular resource assessment updates through reservoir modeling and common management of the resource, which is utilized by several independent companies. Geothermal energy is one of the cleanest energy sources available. In the case of Xianyang the use of geothermal water instead of coal will reduce CO2 emission by 40,000 tones annually for each 1,000,000 m² of houses connected. |