Abstract:
Objective The Jixian System karst geothermal reservoir serves as the primary production reservoir in the Niutuozhen geothermal field, Xiong’an New Area, where geothermal fluids present pronounced Na+ and Cl− enrichment coupled with SO42− depletion. However, the genetic mechanisms and quantitative dynamics of mineral-fluid interactions responsible for these geochemical signatures remain insufficiently characterized.
Methods To elucidate the origin of fluid components and quantify water-rock interaction processes within the reservoir, this study analyzed 40 surface water and groundwater samples from the Jixian System’s Wumishan and Gaoyuzhuang formations. Integrating hydrochemistry, stable isotopic tracers, and hydrogeochemical inverse modeling, this study delineated the evolutionary pathways of fluid geochemistry.
Results The results demonstrate that the geothermal fluids in the karst reservoir primarily originate from atmospheric precipitation, exhibiting high Na+, Cl−, and Total Dissolved Solids (TDS) concentrations alongside low SO42− levels. After infiltration, the meteoric water undergoes deep thermal heating during long-distance migration and interacts extensively with surrounding rocks through dissolution, cation exchange, and sulfate reduction, ultimately forming the current geochemical characteristics. Hydrogeochemical modeling indicates substantial mineral reaction quantities and rates along the migration pathway from the Taihang Mountain recharge area to the study area, with these parameters decreasing significantly during internal flow processes within the geothermal field. Grounded in a detailed analysis of water-rock interaction geochemistry, this study pioneers the application of inverse hydrogeochemical modeling to quantify the relative contributions of mineral dissolution-precipitation reactions to hydrogeochemical evolution.
Conclusions By establishing a mechanistic link between mineral phase transformations and fluid chemistry dynamics, the findings elucidate the multistage evolutionary pathways of geothermal systems while providing a novel methodological framework for geothermal resource assessment. This integrated approach not only advances understanding of subsurface fluid-rock coupling processes but also offers critical scientific support for sustainable development strategies in geothermal energy exploitation.
下载:
邮件订阅
RSS