陕北侏罗系含水层富水性不均一，实际矿井涌水量与勘探阶段预测值差异较大，为了提高矿井涌水量预测准确性，科学高效指导矿井防治水，采用沉积微相划分、地学信息定性统计与灰色关联定量分析、微观孔隙结构实验室测试等方法分别研究了陕北侏罗系沉积微相、岩性及其组合、微观孔隙结构与富水性的关系，揭示沉积控水机理，总结沉积控水规律，划分沉积控水模式。结果表明：侏罗系砂岩含水层中粗砂岩、中砂岩等粗碎屑岩厚度越大，富水性越强，泥岩与砂质泥岩等细碎屑岩厚度越大，富水性越弱；砂岩地层风化程度相同时，微观孔隙结构分类级别（包括大孔粗喉型（Ⅰ类）、中孔-中-细喉型（Ⅱ类）、小孔细喉型（Ⅲ类）、小-微孔-微细喉型（Ⅳ类））越低，粒度越粗，含水层富水性越强，风化程度不同时，同时代地层风化程度越强，砂岩微观孔隙结构分类级别越低，粒度越粗，含水层富水性越强；侏罗系直罗组含水层主要为河流沉积体系，曲流河、辫状河沉积相，河道、河漫滩沉积微相，相同沉积相条件下河道较河漫滩沉积微相富水性强，河道岩性以砾岩、粗砂岩、中砂岩为主，延安组上部地层以三角洲沉积体系为主，三角洲平原沉积相，分流河道与分流间湾沉积微相，分流河道较分流间湾沉积微相富水性强，分流河道岩性以中砂岩为主，偶见粉砂岩；研究区沉积控水模式划分为辫状沉积强富水性型、曲流河沉积中等富水性型、三角洲平原分流河道沉积弱富水性型、三角洲平原分流间湾沉积极弱富水性型等四种类型。研究成果可为含水层富水性预测与矿井水害防治提供科学依据。

There is uneven water-enrichment in Jurassic sandstone aquifers in northern Shaanxi Province,and a great difference between actual mine water inflow and the predicted value at exploration stage.In order to improve the prediction accuracy of mine water inflow,scientifically and efficiently guide mine water prevention and control,this paper respectively studied the relationship between sedimentary micro-facies,lithology and its assemblage,microscopic pore structure and water-enrichment using sedimentary micro-facies division,qualitative statistics of geological information and grey correlation quantitative analysis,laboratory test of microscopic pore structure from the angle of sedimentary water control.The mechanism of sedimentary water control was revealed and the law of sedimentary water control was summarized,then,the sedimentary water control mode was put forward.The results show that:① the thicker the coarse clastic rocks such as coarse sandstone and middle sandstone is,the stronger the water-enrichment it is,and the thicker the fine clastic rocks such as mudstone and sandy mudstone is,the weaker the water-enrichment it is.② When the degrees of weathering are the same,the lower the classification level of sandstone microscopic pore structure (The microscopic pore structure include type Ⅰ for large pore and coarse throat,type Ⅱ for mesopore and middle-fine throat,type Ⅲ for keyhole and fine throat,type Ⅳ for small-microporous and micro-fine throat) and the coarser the grain size are,the stronger the water-enrichment aquifer is,while the degrees of weathering are different and the stratigraphic age is the same,the lower the classification level of sandstone microscopic pore structure and the coarser the grain size are,the stronger the water-enrichment aquifer is.③ The Zhiluo Formation aquifer is dominated by fluvial sedimentary system,and the sedimentary facies are meandering river and braided river,sedimentary microfacies are channel and floodplain.When the sedimentary facies are the same in Zhiluo Formation aquifer,the water-enrichment of channel sedimentary microfacies are stronger than that of the floodplain sedimentary microfacies,and the lithology of channel sedimentary is mainly conglomerate,coarse sandstone and middle sandstone.The upper strata of Yan’an formation aquifer is dominated by delta sedimentary system,delta plain sedimentary facies,distributary channel and distributary bay sedimentary microfacies,and the water-enrichment of distributary channel are stronger than that of the distributary bay sedimentary microfacies,and the distributary channel is mainly composed of middle sandstone,occasionally siltstone.④ The sedimentary water control model in the study area has been divided into four types,which are braided river sedimentary and strongly water-enrichment type,meandering river sedimentary and medium water-enrichment type,delta plain distributary channel sedimentary and weak water-enrichment type,delta plain distributary interbay sedimentary and extremely weak water-enrichment type.The research results can provide scientific basis for aquifer water-enrichment prediction and mine water disaster prevention.

1 研究区概况

2 沉积控水规律

   2.1 沉积相

   2.2 岩性及其组合

   2.3 微观孔隙结构

   2.4 沉积控水各要素之间的关系

3 沉积控水模式

4 结论