地热储层中氟迁移的多因素影响研究  

Study on Multifactorial Influences of Fluoride Migration in Geothermal Reservoirs

作　　者：赵丽[1,2] 胡鸿博 张庆 邢明飞 刘亦菲[1] ZHAO Li;HU Hongbo;ZHANG Qing;XING Mingfei;LIU Yifei(School of Resources and Environment,Henan Polytechnic University,Jiaozuo 454000,China;Shaanxi Key Laboratory of Prevention and Control Technology for Coal Mine Water Hazard,Xi’an 710077,China)

机构地区：[1]河南理工大学资源环境学院,河南焦作454000 [2]陕西省煤矿水害防治技术重点实验室,陕西西安710077

出　　处：《环境科学与技术》2025年第2期105-111,共7页Environmental Science & Technology

基　　金：国家自然科学基金项目(52370135);陕西省煤矿水害防治技术重点实验室开放基金项目(2021SKMS04);河南理工大学博士基金(B2022-38);2024年度河南省科技攻关项目(242102320079)。

摘　　要：该研究以新近系明化镇组地热储层为研究对象,通过土柱模拟实验,探讨了不同静水压力和多离子共存条件下F^(-)在砂土中的迁移规律。研究结果表明:随着静水压力的增加,F^(-)穿透曲线右移,开始穿透时间及峰值到达时间均延长。双点位模型对不同静水压力下F^(-)的穿透曲线拟合效果较好,拟合结果显示,弥散系数和阻滞系数均随静水压力的增加而增大,表明弥散作用和吸附能力均得到了增强。常压下F^(-)的吸附过程是受速率限制的,而高静水压力下F^(-)的迁移则处于瞬时吸附平衡状态,符合局域平衡假设。对于高静水压力下不同注入方式对F^(-)迁移的影响,结果表明NaF合加NaCl或Na_(2)SO_(4)溶液的穿透曲线相较于单加NaF溶液的穿透曲线呈右移趋势,开始穿透时间和峰值到达时间均有所延迟,尤其在NaF合加Na_(2)SO_(4)溶液条件下延迟最为显著。对流弥散方程对多离子共存条件下的F^(-)穿透曲线拟合度较高,拟合结果表明土柱实验主要由对流作用主导,弥散作用则以机械弥散为主。尽管弥散系数相差不大,在相同Na^(+)浓度条件下,阻滞系数仍差异显著,具体为R_(NaF+Na_(2)SO_(4))>R_(NaF+NaCl)>R_(NaF),Na^(+)并非直接导致氟吸附性增强的原因,而Cl^(-)和SO_(4)^(2-)的存在能显著增强砂土对F^(-)的吸附能力,且SO_(4)^(2-)的影响大于Cl^(-)。该研究为理解不同静水压力和多离子共存条件下F^(-)的迁移行为提供了新的视角,并通过实验和模型拟合深入揭示了相关机制,对环境水文地质和污染物迁移预测具有重要参考价值。This study focuses on the geothermal reservoir of the Minghuazhen Formation in the Neogene Period,and the migration behavior of fluoride(F^(-))in sandy soil under different hydrostatic pressures and multi-ion coexistence conditions was explored by means of soil column simulation experiments.The results of the experimental study showed that with the increase of hydrostatic pressure,the breakthrough curve of F^(-)shifts to the right,and both the breakthrough time and peak arrival time were extended;the TSM(two-site model)model well fitted the breakthrough curves of F^(-)under different hydrostat-ic pressures,the fitting results indicating that both the dispersion coefficient and retardation coefficient increased with the rise of hydrostatic pressure,showing enhanced dispersion and adsorption capacities.Under normal pressure,the adsorption process of F^(-)was rate-limited,while under high hydrostatic pressure,F^(-)migration reached an instantaneous adsorption equi-librium state,consistent with the LEA(local equilibrium assumption);and regarding the impact of different injection methods on F^(-)migration under high hydrostatic pressure,the results revealed that the breakthrough curve of the mixed injection of NaCl or Na_(2)SO_(4) solutions shifts to the right compared to that of the NaF solution alone,with delayed breakthrough and peak arrival time,which was particularly significant under the Na_(2)SO_(4) solution condition.The CDE(convection-dispersion equa-tion)model with a high degree of fitting in terms of the F^(-)breakthrough curve under multi-ion coexistence condition,indicated that the soil column experiment was primarily dominated by convection,with mechanical dispersion playing a major role in dispersion.In addition,despite the small differences in dispersion coefficients,the significant differences of retardation coefficients were observed in the same condition of Na^(+)concentration;specifically speaking,the coefficients being in order of decreasing magnitude:RNaF+Na_(2)SO_(4)>RNaF+NaCl>RNaF;and Na^(+)was

关 键 词：孔隙型地热储层 氟离子 共存离子 静水压力 迁移规律 吸附 

分 类 号：X53[环境科学与工程—环境工程]