Chemical Characteristics and Genetic Analysis of Underground Thermal Storage Water In Yangbajing Geothermal Field

Chemical characteristics and genetic analysis of underground thermal storage water in Yangbajing Geothermal Field Yangbajing Geothermal field is a world-famous high-temperature geothermal field. Taking the geothermal fluid in Yangbajing Geothermal Field as the research object, this paper analyzes the hydrochemical characteristics of the geothermal fluid in this area through Piper diagram, component relationship diagram and scatter diagram, discusses the recharge depth and source of hot water by using hydrogen and oxygen isotopes, and estimates the heat storage temperature combined with cation thermometer and solveq software. The research shows that the cation of geothermal water is mainly Na+, the anion is mainly Cl-, and the hydrochemical type is mainly Na-Cl, while the hot spring and cold spring are mainly Na-HCO3-Cl, Na-Cl-HCO3 and Na-HCO3. The supply sources are mainly atmospheric precipitation and ice snow melt water, supplemented by water rock interaction and deep hot water supply. The circulation depth is about 5200~5400 m, and the heat storage temperature is about230~ 260℃, Under the combined action of head pressure and density difference, the underground thermal fluid moves upward along the channel formed at the intersection of the deep NE and NW fault systems in the north area, forming a deep bedrock fissure reservoir dominated by metamorphic rock and granite in the north area and a shallow reservoir dominated by Quaternary sandy conglomerate in the south area. Good water supply, reservoir cap conditions, development structure and heat source conditions make the study area form a high-temperature geothermal fluid dominated by Na-Cl hydrochemical type and characterized by high B, F, K and Li.