鄂尔多斯盆地马家沟组马五_1亚段地层水特征及对CO_2地质封存的意义  

Water characteristics of Majiagou formation Ma5_1 submember in Ordos Basin and the significance for CO_2 geological sequestration

作　　者：孙玉景 周立发[1,2] 霍斐斐 SUN Yujing;ZHOU Lifa;HUO Feifei(Department of Geology,Northwest University,State Key Laboratory of Continental Dynamics,Xi’an 710069,China;National & Local Joint Engineering Research Center of Carbon Capture and Storage Technology,Xi’an 710069,China)

机构地区：[1]西北大学地质学系大陆动力学国家重点实验室,西安710069 [2]二氧化碳捕集与封存技术国家地方联合工程研究中心,西安710069

出　　处：《地球环境学报》2019年第1期49-57,共9页Journal of Earth Environment

基　　金：国家重点研发计划项目(2016YFE0102500)~~

摘　　要：CO_2地质封存技术是实现碳减排的有效措施,对鄂尔多斯盆地马家沟组马五_1亚段地层水特征进行研究,是下一步实施工程化CO_2封存的首要前提。本文依据对深部钻井取样的直观观察与实验测试,采用单项指标分类评价和多项指标综合评价的方法深入分析了马家沟组马五_1亚段地层水的物理性质、化学性质、地层水类型和水化学特征参数。结果表明:马家沟组马五_1亚段地层水密度较大、矿化度极高,属于卤水,含量最多的离子是Cl^-,其次是Ca^(2+),地层水是CaCl_2型。钠氯系数、氯镁系数、脱硫系数和镁钙系数的分析表明马五_1亚段地层水封闭性极好,处于较强的还原环境。综合分析认为马家沟组马五_1亚段地层水具备实施CO_2封存的良好条件,非常适宜进行CO_2封存。Background, aim, and scope Global warming caused by emission of greenhouse gases dominated by CO2 has become a severe challenge to human being. Many measures have been taken to combat global warming all over the world. What is worth mentioning is the CO2 geological sequestration, it is an effective and burgeoning measure to achieve carbon emission reduction. The CO2 sequestration potential is very huge in Ordos Basin. So, in this paper the formation water characteristics in Ma51 submember of Majiagou formation are systematically studied, which is the precondition for further engineering design of CO2 sequestration in Ordos Basin. Materials and methods Based on the direct observations and experimental tests of deep drilling samplings, the method of “single index classification evaluation and multiple index comprehensive evaluation” is adopted. The physical properties, chemical properties, formation water types and hydrochemical characteristic parameters of the Majiagou formation Ma51 submember are analyzed in detail. Results The results indicate that the pH of the water ranges from 3.5 to 8.6, mainly from 4.5 to 6.5;the water density ranges from 1.0g·cm^-3 to 1.5 g·cm^-3, mostly 1.1 - 1.3 g·cm^-3;the mineralization degree is generally greater than 50 g·L^-1, and average mineralization degree is 166 g·L^-1;the highest concentration ion is Cl^-, followed by Ca2+;the concentration order of the ions is r Cl^-> r Ca^2+>r ( Na^++ K^+)>r Mg^2+>r HCO>r SO, and the formation water is CaCl2 type. The analysis results of water chemical characteristic parameters show that Na / Cl factor (r Na^+/ r Cl^-) ranges from 0.18 to 0.55, 0.34 on average;Cl / Mg factor (r Cl^-/ r Mg^2+) ranges from 11.04 to 165.16, 32.11 on average;desulfurization factor (100 × r SO/ r Cl^-) ranges from 0 to 0.45, 0.09 on average;Mg / Ca factor (r Mg^2+/ r Ca^2+) range from 0.01 to 0.30, 0.17 on average. Discussion Most samples have a pH of 4.5 - 6.5, which does not meet the drinking water standard (6.5 - 8.5). The density is generally 1.1 -

关 键 词：马五1亚段 矿化度 卤水 CO2封存 鄂尔多斯盆地 

分 类 号：P618.13[天文地球—矿床学]