Enhanced Geothermal Systems: International developments and China’s prospects
XU Tianfu, ZHANG Wei
1 Key Laboratory of Groundwater Resources and Environment, Ministry of Education Jilin University, Changchun 130021 2 National Geological Laboratory of China (Geoscience Documentation Center. CGS), Beijing 100083
An Enhanced Geothermal System (EGS) refers to artificial terrestrial heat engineering. In the system, the artificial geothermal reservoir is constructed by means of hydraulic fracturing in low permeability hot dry rock (HDR) and a large amount of terrestrial heat is collected. HDR is hot rock without water or steam. It is generally buried deep underground, 3~10 km under the Earth surface at a temperature of 150~ 650 ℃. The energy stored in HDR is 30 times the total amount in oil, nature gas and coal all over the world. EGS research has been carried out over the last 40 years in the United States, Britain, France, Japan, Australia, etc. China only began EGS study a few years ago. Currently HDR exploitation faces many challenges, such as the construction of massive artificially fractured geothermal reservoirs. So EGS commercialization needs further research and technological development. In this paper typical EGS demonstration projects and research work carried out in USA are shown. The prospects of EGS in China are discussed.
Key words：
hot dry rock ; enhanced geothermal system ; hydraulic fracturing ; thermal reservoir construction ; egs demonstration
