浅埋房柱近距离煤层安全开采顶板应力控制

Roof stress control of near distance coal seam safety mining with shallow buried room-pillar

韩家湾煤矿2-2煤层采用房柱式开采方式,煤柱在底板形成集中应力,使3-1煤层的开采产生一定的安全隐患。为解决近距离煤层安全开采厚硬岩层顶板聚集较大能量,可能诱发大面积压架或矿震的问题,实现韩家湾煤矿下组煤三盘区3-1煤层的安全开采,采用水力压裂技术对致密厚岩层进行弱化。在分析覆岩特征及潜在顶板灾害特征的基础上,基于三盘区下组煤开采过程中对上部2-2煤层遗留条带煤柱与房柱煤柱的扰动机理,设计采用长水平孔区域压裂技术对2-2煤层的2处大巷煤柱区域进行水压致裂,初步提出了区域压裂技术参数、定向长钻孔压裂工艺。

The 2-2 coal seam of Hanjiawan coal mine adopts room-pillar mining mode,and the coal pillar forms concentrated stress in the floor,which causes certain safety risks for 3-1 coal seam mining.In order to solve the problem that a large amount of energy accumulates in the roof of thick and hard rock strata during the safe mining of close coal seam,which may induce large-area shelving or mine earthquake,hydraulic fracturing technology is proposed to weaken the dense and thick rock strata.After the analysis of characteristics of the overlying rock and roof hazard,and based on the mechanism of disturbance on the left strip coal pillar and room-pillar coal pillar of the upper 2-2 coal seam during the mining process of the lower group coal of the three panel area,we adopt long-level-hole locally fracturing technology to carry out the hydraulic fracturing of the two roadways’coal pillars of the 2-2 coal seam,and put forward local fracturing technological parameters and directional long borehole fracturing technique.