Overall Conditions of Yang Yi Geothermal Field

Abstract

Yang Yi Geothermal Field is located in Dangxiong County, Tibet, about 50 km from Yangbajing Geothermal Field and 75 km from Lhasa. With an average altitude of 4,800 m, it is located in a marsh grassland, semi-drought climatic region of the plateau. The highest and lowest temperatures ever recorded are 21 and ñ31 oC respectively. The water boiling point under the local atmospheric pressure (0.6 kg/cm2) is 85 oC. Based on geophysical studies and geothermal reservoir engineering tests, the total area of the geothermal field is estimated to be 10.76 km2. It is a tectonic-fissure type hightemperature geothermal field, which is controlled mainly by tectonic fractures stretching from south to north. The highest temperature in the field is 207 oC. The average temperature in the high-temperature region of the geothermal reservoir is 172 oC, and the maximum lip pressure, maximum static pressure and maximum working pressures are 3 kg/cm2, 9.4 kg/cm2 and 11.3 kg/cm2 respectively. The corresponding flow rate for a single well is more than 100 T/h, in terms of total quantity of steam and water.