【摘要】 我国西部黄陇煤田降雨量少、蒸发强烈,属于干旱半干旱地区,做好煤炭开采过程中对含水层的保护工作极为重要。为研究适用于黄陇煤田深埋煤层开采顶板洛河组砂岩含水层的保水技术,以彬长矿区为研究区,采用砂岩孔隙度测试,结合非线性回归分析方法,研究洛河组地层不同深度砂岩渗透性变化;开展水化学测试,分析非均质洛河组含水层垂向水化学场特征;结合地面和井下水文地质探查,进一步定量化研究洛河组含水介质的非均质性。在查明洛河组含水地层非均质性的基础上,建立含水层下段受裂隙带波及条件下地下水渗流数值模型,研究基岩含水层局部受裂隙带影响条件下的渗流规律。根据渗流规律研究深埋煤层开采顶板基岩含水层保水开采技术,结合彬长矿区工作面开采实际揭露水位变化情况对其进行验证。研究表明,洛河组含水层渗透性随地层深度的增加而呈负指数降低,随着埋深增大含水层水化学类型由HCO₃-Ca型转化为SO₄-Na型,同时上段的单位涌水量约为下段的7倍,可知洛河组含水层上、下段地下水渗流条件不同,垂向非均质性较强。工作面开采裂隙带仅波及含水层下部时,含水层仅受波及层和相邻层的水位下降明显,上部未受到波及段水位降深有限,整个含水层不会出现水位统一下降的现象,而是呈现出不同层位水位降深差不同的差异性渗流规律。鉴于此,提出利用含水层非均质性特征,以控制含水层上段水位降深为核心,允许导高适当波及含水层下段的"控水开采"技术,有助于缓解深埋煤层采煤与保水的矛盾。通过彬长矿区胡家河煤矿现场应用表明,洛河组含水层实际渗流特征符合本次研究成果,控水开采技术可实现洛河组砂岩含水层保水开采的目的。更多还原

【Abstract】 Huanglong Coalfield,located in the northwest of China,has low rainfall and strong evaporation,and belongs to arid and semi-arid areas.The protection of aquifers during coal mining is extremely important.In order to study the water-preserved mining technology applied to the Cretaceous Luohe Formation sandstone aquifer in the deep coal seam mining,the Binchang mining area was selected as the research area.Sandstone porosity test combined with nonlinear regression analysis was used to study the permeability variation of sandstone in different depths of the Luohe Formation.Moreover,this study analyzed the vertical water chemical field heterogeneous characteristics of the Luohe Formation aquifer by using hydrochemical tests.In addition,the Luohe Formation heterogeneous medium parameters were quantitatively studied through the surface and underground hydrogeo-logical exploration.Based on the heterogeneity of the Luohe Formation aquifer,a numerical model of groundwater seepage under the condition of the water-flowing fractured zone only affects the lower aquifer was developed,and the seepage law in this condition was studied.According to the seepage laws,the water-preserved mining technology in deep coal seam mining is studied.Combined with the water level changes in the mining conditions of coal mining face in Binchang mining area,the water-preserved mining technology was verified.The results showed that the permeability of the Luohe Formation aquifer decreases negatively,and the chemical type of the aquifer is converted from the type of HCO₃-Ca to the SO₄-Na,and the specific yield of the upper aquifer is about seven times that of the lower with the increase of the depth of the formation.The groundwater seepage conditions in the upper and lower sections of the Luohe Formation aquifer are different,and the law of vertical heterogeneity is confirmed.When the water-flowing fractured zone only affects the lower section of the aquifer,only the drawdown of the lower section and adjacent layers is significantly,and the water lever change of upper section is not evident.The drawdown is not uniform in the whole aquifer,and the seepage laws of different sections are different.Based on the law of seepage,the water-controlled mining technology is proposed by using the heterogeneity characteristics of the aquifer to control the drawdown of the upper section of aquifer.It is permissible to be affected by the water-flowing fractured zone in the lower section of aquifer.The technology helps to alleviate the contradiction between coal mining and water protection.Through the application of Hujiahe Coal Mine in Binchang Mining Area,the seepage field of the Luohe Formation aquifer is consistent with the results of this study.The water-controlled technology can realize the purpose of water conservation of the Luohe Formation sandstone aquifer.更多还原