Hot Water Geochemical Characteristics And Geothermal Resource Potential Evaluation In Hot Water Reservoir Area In Dayu County,Jiangxi Province

Geothermal resources are pollution-free,recyclable and clean energy,which have attracted much attention.The research area is located in Hotshuitang Village,Hedong Township,about 30km southwest of Dayu County,Jiangxi Province.The regional location is in the complex influence zone between the eastern section of the east-west complex structural belt of Nanling and the southern part of the south-north structure of Zhuguang Mountain.Since the upper Paleozoic,the tectonic activity in this area has been frequent,gradually forming the uplift of the western section and the south-north margin and the sag of the middle-east section.Successive tectonic movements produced different tectonic systems throughout the region.The exploration area belongs to the Dayu Dong-Nancheng fault tectonic belt of the New Cathayxia system,forming the east-oriented fault structure,secondary faults and structural joints development,resulting in a large number of joints,fractures and fracture zones,which create good conditions for the occurrence and migration of groundwater.The hot pond hot spring is located in the complex part of the n NE structure and n W structure.A good geothermal resource reservoir is formed at the intersection of the north-easterly deep and large fault structure(F1)and the north-westerly fault.By studying and testing the geological conditions,hydrochemical properties,geothermal temperature distribution,reservoir characteristics,water flow dynamic monitoring and water quality health indexes of the geothermal resources in the study area,the following conclusions are drawn:(1)The geothermal resources of hot reservoirs are controlled by the NW-trending deep and large compression-torsion fault F1 and the NW-Trending F2 faults.The F1 deep and large faults provide thermal cycling conditions,while F2 is a fracture zone and provides water conductivity conditions for geothermal resources.The combination of the two promotes the geological conditions of geothermal water resources in this area.(2)through the hot pool of geothermal resources to study the reservoir,the geothermal field as part of the ribbon small low temperature geothermal field(?-2),the temperature is 46.8?48.8?,nissan heat energy of about 1960.57 k W,annual production capacity of about 1.03 x10⁸ mj,sections of standard coal amount is about 3.52 x 10³ t.(3)The water quality type of geothermal hot water is low salinity-hemosilicic acid-calcium bicarbonate type fresh water,geothermal fluid hemosilicic acid(H₂Si O₃)94.3?137.25mg/L,fluorine(F?)2.83?9.67mg/L,the content has reached and exceeded the requirements of"named ore water concentration".(4)Based on the water quality analysis of the geothermal field,if the content of harmful substances is lower than the national sewage discharge index,the geothermal field can be used for heating,physiotherapy,bathing,tourism and leisure purposes,and the discharge will not cause pollution to the soil and atmosphere.