摘要
The Xi'an Depression in the Guanzhong Basin of western China has been suggested to contain geothermal resources that could aid China in achieving carbon neutrality and optimizing energy structure.However,the high concentration of total dissolved solids(TDS)and scale-forming ions in geothermal water from the depression causes severe scaling problems in harvesting geothermal energy.To reduce scale-related problems,accurate identification of scale types and prediction of scaling during geothermal energy utilization are crucial.This study starts with identifying the types and trends of scaling in the study area,using index-based discriminant methods and hydrogeochemical simulation to calculate and analyze the mineral saturation index of water samples from some wellheads and of reconstructed fluid samples of geothermal reservoirs.The results indicate that the scales are mostly calcium carbonate scales rather than sulfate scales as a result of temperature changes.Several portions of the geothermal water systems are found to have distinct mineral scaling components.Quartz and chalcedony are formed in low temperature areas,while carbonate minerals are in high temperature areas.Despite the low iron content of geothermal water samples from the study area,scaling is very common due to scaling-prone iron minerals.The findings can be used to evaluate geothermal drainage systems and guide anti-scaling during geothermal energy utilization in similar settings.
基金
supported by the Research Project on Middle and Deep Geothermal Energy Utilization in Guanzhong Area of Shaanxi ProvincedSpecial Study on Sandstone Thermal Storage Recharge(No.21152920349)
the Special Fund for Basic Scientific Research Operating Expenses of Central Universities of Chang'an University(Grant No.300102292903)
the Basic Research Plan of Natural Sciences of Shaanxi Province General Project“Study on Loess Landslide Chronology Based on OSL Dating Technology”(Grant No.2017JM4018)
the Open Fund of State Key Laboratory of Loess and Quaternary Geology(Grant No.SKLLQG1933).
