传统水化学地热温度计的适用性分析  

The applicability of traditional chemical geothermometers

作　　者：李洁祥 许亚东 蔺文静[3,4] LI Jiexiang;XU Yadong;LIN Wenjing(School of Resources and Environment,Henan Polytechnic University,Jiaozuo 454100,China;Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization,Jiaozuo 454100,China;Institute of Hydrogeology and Environmental Geology,Chinese Academy of Geological Sciences,Shijiazhuang 050061,China;Technological Innovation Center of Geothermal&Hot Dry Rock Exploration and Development,Ministry of Natural Resources,Shijiazhuang 050061,China)

机构地区：[1]河南理工大学资源环境学院,河南焦作454100 [2]煤炭安全生产与清洁高效利用省部共建协同创新中心,河南焦作454100 [3]中国地质科学院水文地质环境地质研究所,河北石家庄050061 [4]自然资源部地热与干热岩勘查开发技术创新中心,河北石家庄050061

出　　处：《地学前缘》2024年第6期145-157,共13页Earth Science Frontiers

基　　金：国家自然科学基金青年项目(42102297);国家重点研发计划项目(2021YFB1507401);青海省清洁能源矿产专项(2022013004qj004)。

摘　　要：水化学地热温度计是估算水热型地热系统热储温度的一种重要手段,为了厘清传统水化学地热温度计的局限性和有效性,此次将对水化学地热温度计展开全面分析。结果表明:部分水化学平衡体系受区域地质条件的影响,致使对应的水化学地热温度计(Na-Li地热温度计、Li-Mg地热温度计、Ca-Mg地热度计和SO_(4)-F地热温度计等)缺乏普适性,而Na-K-Ca地热温度计(β=1/3)可能受多种水化学因素的制约,在中低温地热系统中应谨慎使用;Na-K地热温度计、K-Mg地热温度计和SiO_(2)温度计更适用于水热型热储温度的计算,高温热储层(>200℃)中水岩相互作用强烈,Na-K地热温度计的计算结果相对准确,在估算中低温热储层温度时,K-Mg地热温度计和SiO_(2)温度计则更为合适,而在沉积盆地型地热系统,不建议使用水化学地热温度计直接估算地热水的平衡温度。除此之外,判识热储层的存在和地热水水岩平衡状态的分析是选取水化学地热温度计的前提条件,然而即使在水化学地热温度计的适用范围内,对水化学地热温度计计算结果的对比验证仍然必不可少;高温地热系统中地热水的混合过程可用于验证水化学地热温度计的准确性,而在中低温地热系统,随着水岩相互作用程度降低,水化学地热温度计估算结果的不确定性也随之增加,综合多种方法对热储温度值的分析验证就显得更为重要。此次研究可为合理选取水化学地热温度计提供一定的理论参考。Geothermometers are used to estimate the reservoir temperatures in hydrothermal systems.To clarify the limitations and validity of traditional chemical geothermometers we conduct a comprehensive review in this study.We found that certain chemical geothermometer types(Na-Li,Li-Mg,Ca-Mg,SO_(4)-F)were not widely usable,as hydrochemical equilibrium systems in some areas were influenced by the regional geological conditions.Meanwhile,the use of Na-K-Ca type(β=1/3)was constrained by a variety of hydrochemical factors,thus it should be used with caution in low-medium-temperature geothermal systems.The types more suitable for estimating the reservoir temperatures were Na-K,K-Mg,and SiO_(2).The Na-K type gave relatively accurate estimates for the high-temperature reservoirs(>200℃)where extensive water-rock reactions occurred;while the K-Mg and SiO_(2) types were more suitable for the low-medium-temperature reservoirs.In sedimentary geothermal systems,chemical geothermometers were not recommended for estimating the equilibrium temperature of geothermal waters directly.Besides,determining the occurrence state and the hydrothermal equilibrium status of a geothermal reservoir was prerequisite for selecting chemical geothermometers;yet,even within a suitable application range,the measurement results should be compared and validated against the calculation results.In high-temperature geothermal systems the accuracy of chemical geothermometers could be verified by the mixing processes;in low-medium-temperature systems the measurement uncertainty increased due to lack of extensive water-rock reactions,thus validation by various methods became even more important.Results from this study can be used to guide the selection of chemical geothermometers.

关 键 词：水热型地热系统 水化学 地热温度计 水岩反应 平衡 

分 类 号：P641.3[天文地球—地质矿产勘探]