呼吉尔特矿区深埋工作面顶板水文地质特征

Hydrogeological Characteristics of Roof of Deep Buried Working Face in Hujirt Mining Area

鄂尔多斯盆地侏罗纪深埋煤田区作为我国未来煤炭资源开发的重点区域,防治水工作是矿井安全生产面临的最重要任务。为了查清主采煤层顶板水文地质特征,以呼吉尔特矿区深埋工作面为研究对象,从地质沉积、含水层空间分布、富水规律和工作面涌水量等方面开展研究。结果表明:受河流相沉积控制,呼吉尔特矿区主采煤层顶板发育了砂泥岩互层结构地层,受毛乌素沙漠强富水松散层水下渗作用,作为直接充水含水层的真武洞砂岩和七里镇砂岩具有'高水压、强富水、非均一'特征,特别是七里镇砂岩含水层,未扰动条件下水压为6 MPa,井下单孔涌水量为150~160 m^3/h;工作面放水试验和采前预疏放结果表明,直接充水含水层具有良好的可疏降性,先期开采段(0~600 m)采前大部分顶板钻孔水量降至5 m^3/h以下,水压降至1 MPa以下,具备安全回采的水文地质条件;整个工作面回采过程中,总的排水量高达787.0×10~4m^3,富水系数为1.48,远大于神府、新街等矿区,表明呼吉尔特矿区煤层顶板直接充水含水层富水性较强,必须加强防治水工作,以保证本地区煤炭资源的安全开发。

Jurassic deep-buried coalfield in Ordos Basin was the key area of coal resources development in the future.Water control was the most important task for mine safety production.In order to make clear the hydro-geological characteristics of the coal seam roof,researches were carried out on geological deposits,spatial distribution of aquifers,water-rich laws and surface water inflow in deep-buried working face of Hujirt Mining Area.The results showed that sand shale interbed was developed on the roof of main coal seam in Hujirt Mining Area,which was influenced by fluvial deposits.Due to the infiltration of the strong water-rich loose layer in Maowusu Desert,the Zhenwudong sandstone and Qilizhen sandstone had the characteristics of high water pressure,strong water-rich and non-uniform.Especially in undisturbed Qilizhen sandstone aquifer,the water pressure and the single borehole water inflow were 6 MPa and 150 m^3/h to 160 m^3/h respectively.The results of drainage test and pre-drainage before coal mining showed that the aquifers directly filled with water had good drainability.Most of the roof borehole water inflow and pressure were reduced to less than 5.0 m^3/h and 1.0 MPa respectively before coal mining in advanced mining section(0 m to600 m).During the whole mining process,the total drainage was 787×10~4 m^3 and the water-rich coefficient was 1.48.The waterrich coefficient was greater than the value in Shenfu and Xinjie Mining Area.Direct water-filled aquifers of coal seam roof were rich in water in Hujirt Mining Area.In order to ensure the safe development of coal resources in Jurassic deep-buried coalfield in Ordos Basin,it was necessary to strengthen water prevention and control work.