环境温度对盐湖卤水化学组成及储卤层渗透性变化的制约  

Constraint of Environmental Temperature on Chemical Composition of Brine and Permeability of Aquifer in the Saline Lake

作　　者：袁小龙[1,2,3] 张西营 盛金昌[3] 高东林 李斌凯[1,2] 都永生[1,2] 万维汉 YUAN Xiaolong;ZHANG Xiying;SHEN Jinchang;GAO Donglin;LI Binkai;DU Yongsheng;WAN Weihan(Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources,Qinghai Institute of Salt Lakes,Chinese Academy of Sciences,Xining,810008;Key Laboratory of Salt Lake Geology and F~nvironment of the Qinghai Province,Qinghai Institute of Salt Lakes,Chinese Academy of Sciences,Xining,810008;College of Water Conservancy and H ydropozoer Engineering,Hohai University,Nanj ing,210098;Lenghu Bindi Postash Co.,Ltd.Haixizhou,Qinghai,817000)

机构地区：[1]中国科学院青海盐湖研究所中国科学院盐湖资源综合高效利用重点实验室,西宁810008 [2]青海省盐湖地质与环境重点实验室,西宁810008 [3]河海大学水利水电学院,南京210098 [4]滨地钾肥有限责任公司,青海海西州817000

出　　处：《地质学报》2018年第8期1724-1732,共9页Acta Geologica Sinica

基　　金：西部之光项目"柴达木盆地杂卤石矿层储集性能评价及最佳溶采区";国家自然科学基金面上项目(编号41672087;51579078;51679070);国家重点基础研究发展计划项目(编号2017YFC1502600)资助的成果

摘　　要：柴达木盆地昆特依盐湖浅部储卤层是一个多场耦合的动态平衡系统,受到水动力、气候、化学等多种因素控制。本文对昆特依盐湖浅部储卤层不同季节(夏季和冬季)卤水组成和储卤层渗透性特征进行了分析研究。结果表明:卤水中的主要离子含量从夏季到冬季发生了明显的变化,其中,K、Mg、Ca、Cl的含量都相应增加,增加幅度为:Cl、Mg、K、Ca;而SO_4^(2-)和Na的含量却均有下降,且SO_4^(2-)下降更显著;抽水试验计算结果发现,从夏季到冬季,钻孔ZK08渗透系数K由178m/d降至97m/d。本文研究表明,随着环境温度的降低,芒硝(Na_2SO_4)从卤水中结晶析出,是以上现象发生的主要原因,随着芒硝的析出,促进了含K、Mg、Ca等硫酸盐矿物(杂卤石)的溶解,使得卤水中K、Mg、Ca浓度增加;另一方面,析出的芒硝一定程度上堵塞了储卤层的孔隙,卤水的粘度也因温度降低而增加,这两个因素共同作用降低了储卤层渗透性。The shallow brine aquifer in the western Qaidam Basin is a multi-coupled dynamic equilibrium system and controlled by hydrodynamic force, climate and chemical factors. The study carried out an analysis for compositions of brine and permeability of brine aquifer in the shallow brine aquifer in different seasons （summer and winter）. The results show that the concentrations of major ions in brine vary obviously from summer to winter and the concentrations of K, Mg, Ca and C1 increase correspondingly, with an increasing order of C1, Mg, K, Ca. While the concentrations of SO42 and Na decrease, with SO42 decreasing more obvious than Na. Calculation results of pumping test suggest that permeability coefficient K in drilling core ZK08 decreases from 178 m/d to 97 m/d from summer to winter. The reason for that is that precipitation of mirabilite（Na2SO4 ）with decreasing of environment temperature not only improves dissolution capacity of K, Mg and Ca in brine and increases concentrations of K, Mg and Ca, but also decreases the permeability of the aquifer. In addition, the viscosity of brine increases with temperature decreasing. Therefore, it can be concluded that two factors jointly result in decreasing of the aquifer permeability.

关 键 词：昆特依干盐湖 环境温度 储卤层渗透性 卤水化学组成 固液转化 

分 类 号：P619.211[天文地球—矿床学]