Characteristics of heat flow and geothermal fields in Ruidian, Western Yunnan Province, China

Abstract

As an important parameter, the temperature of the thermal reservoir is essential to the classification of the geothermal system and the potential of geothermal resources. The inversion coupling study of the geothermal field is an important basis for establishing the genetic model for the geothermal field of Ruidian, Western Yunnan Province, China. With a geothermal flow of up to 120.5mW/m 2 , and an average geothermal gradient of 4.61°C/100m, the Tengchong-Ruidian area is a high temperature geothermal area, where the highest hot spring water temperature can reach 91.5°C. The geothermal reservoirs there can be divided into shallow and deep thermal reservoirs. By using the Log (Q/K) curve method and the Na-K-Mg triangle diagram method, this paper finds that the underground hot water in the study area is in an unsaturated state and mixed with cold water. Then it calculates the thermal reservoir temperature and analyzes the deep temperature characteristics of the subsurface thermal fluid and the mixing process of the hot and cold water using the SiO2 solubility geothermometer, the dissolved chloride-enthalpy plot, the dissolved silica-enthalpy graph, and the linear regression equations iteration solution methods. The conclusion obtained from this study is that the temperature of the shallow thermal reservoir is about 145°C, that the temperature of the deep thermal reservoir about 220°C, and that the proportion of cold water mixed generally between 60% and 70%. The comprehensive research results of the temperature field in the study area provide theoretical and data support for the establishment of the genetic mechanism for the Ruidian geothermal field.