高压水致裂侏罗系巨厚砂岩对工作面顶板水文地质条件的影响研究

Influence of Hydraulic Fracturing of Thick Jurassic Sandstone on Hydrogeological Conditions of Working Face Roof

为查明东滩煤矿63上06工作面高压水致裂顶板关键层工程对顶板水文地质条件的影响,采用导水裂隙带高度探测、连通试验、物探、钻探和水情监测等手段对比分析了水文地质情况的变化。结果表明:压裂裂缝破坏了侏罗系中部泥岩隔水层,改变了工作面顶板充水模式;压裂裂缝成为充水通道,侏罗系上段、下段砂岩水和压裂水成为顶板充水水源,造成工作面涌水量的增大。压裂水对工作面涌水量增大产生短期影响,侏罗系上段砂岩水对工作面涌水量增大产生长期影响。科学配置排水系统,合理设计压裂钻孔位置、压裂层位和压裂强度,能够有效防控高压水致裂工程引发的顶板次生水害风险。研究成果将对类似受工程扰动工作面的顶板水害防治具有一定的借鉴价值。

To investigate the impact of the hydraulic fracturing key layer engineering on the hydrogeological conditions of the roof in the 63-06 working face of Dongtan Coal Mine,comparative analysis of the changes in hydrogeological conditions was carried out using methods such as water fracture zone height detection,tracer testing,geophysical exploration,drilling,and water monitoring.The results show that the fracturing cracks have damaged the mudstone water barrier in the middle of the Jurassic,and changed the water filling mode of working face roof.Fracturing water and water in the upper and lower sections of the Jurassic sandstone become water sources,going through fracturing cracks,resulting in an increase in the water inflow of working face.Fracturing water has a short-term impact on the increase of water inflow in the working face,while water in the upper Jurassic sandstone has a long-term impact.Scientific arrangement of drainage systems,appropriate design of fracturing drilling positions,fracturing layers,and fracturing intensity can effectively prevent the risk of secondary water damage to the roof caused by hydraulic fracturing projects.The research results will benefit the prevention of roof water damage in similar engineering disturbed working faces.