基于陆相沉积控制的主充水含水层富水性三维展布特征  

Three dimensional distribution characteristics of water-richness of main water filling aquifers based on continental sedimentary

作　　者：王朝引 WANG Chaoyin(China Coal Northwest Energy Company Limited,Ordos 017307,China)

机构地区：[1]中煤西北能源有限公司,内蒙古鄂尔多斯017307

出　　处：《煤炭科学技术》2020年第12期198-204,共7页Coal Science and Technology

基　　金：国家自然科学基金资助项目(41302214);中煤科工集团西安研究院有限公司创新基金面上资助项目(2018XAYMS03)。

摘　　要：鄂尔多斯盆地北部属于中生代陆相沉积,受毛乌素沙漠降水入渗强、松散层储水空间大等因素控制,在蒙陕接壤的深埋煤田区形成了"水压高、水量大、富水不均一"的煤层顶板主充水含水层。为查清该含水层富水性空间展布特征,以纳林河二号煤矿为研究对象,采用沉积相分析法开展了层序地层格架、岩石粒径分布、砂泥岩空间展布等研究,采用音频电穿透技术对工作面顶板含水层三维结构特征进行了探测,并利用井下疏放水钻孔对物探结果进行了检查验证,结果表明:纳林河二号矿井延安组三段中上部发育真武洞砂岩,厚5~20 m,连续性好;直罗组一段平行不整合于延安组之上,厚70~90 m,底部七里镇砂岩厚5~23 m,连续性好,自然伽马曲线值低;延安组三段和直罗组一段是3-1煤开采的主充水含水层。延安组和直罗组砂岩含水层受河流相沉积控制,含水层富水性在三维空间上呈条带状分布,其中延安组三段沿北东—南西方向展布,富水性由东南向西北逐渐减弱;直罗组一段沿北北西-南南东方向展布,古河道中心砂地比为0.4~0.7,富水性由西北向东南逐渐减弱,矿井中部富水性相对较强。延安组和直罗组含水层富水区呈北东—南西和北西—南东交叉分布,由于直罗组早期河流回春,水动力条件增强,在直罗组底部发育了曲流河沉积形成的灰绿色、青灰色(含砾)中—粗长石砂岩含水层,导致直罗组含水层整体富水性较延安组含水层强,且与延安组含水层具有垂向连通性。音频电穿透三维探测确定重点异常区,31101工作面顶板钻孔涌水量(>100 m3/h)和水压均较大,31116工作面顶板含水层富水性分布特征也与物探探测结果吻合,证明纳林河二号井田范围内煤层顶板含水层富水性存在区域性差异,单个工作面范围内也存在含水层富水异常区。The northern Ordos Basin belongs to the Mesozoic continental deposit,which is controlled by the factors such as strong rainfall infiltration in Maowusu Desert and large water storage space of loose layer.In the deep buried coalfield area adjacent to Inner Mongolia and Shaanxi,the main water filling aquifer of coal seam roof with"high water pressure,large water volume and uneven water rich"has been formed.In order to find out the spatial distribution characteristics of water abundance of the aquifer,taking the No.2 Coal Mine of Nalinhe as the research object,the sequence stratigraphic framework,rock particle size distribution,sand and mudstone spatial distribution were studied using sedimentary facies analysis method,and the three-dimensional structural characteristics of the roof water bearing layer of the working face were detected by audio frequency electric penetration technology,and the geophysical exploration results were carried out using the underground drainage boreholes inspection and verification.The results showed that Zhenwudong sandstone was developed in the middle and upper part of the third member of Yan’an formation,with a thickness of 5.0~20.0 m and good continuity.The first member of Zhiluo formation was parallel unconformity on the Yan’an formation,with a thickness of 70.0~90.0 m.The Qilizhen sandstone at the bottom of Zhiluo formation was 5.0~23.0 m thick,with good continuity and low value on the natural gamma curve.The sandstone aquifers of Yan’an formation and Zhiluo formation were controlled by fluvial facies deposition,and the water abundance was distributed in strips.The third member of Yan’an formation was distributed along NE-SW direction,and the water abundance was gradually weakened from southeast to northwest;the first member of Zhiluo formation was distributed along the north-south direction,and the sand to land ratio in the center of the ancient channel is 0.4~0.7.The water abundance was gradually weakened from northwest to southeast,and the water abundance in the middle of

关 键 词：富水性 三维展布特征 沉积相 音频电穿透技术 

分 类 号：TD985[矿业工程—选矿]