磨砂射流轴向切顶压裂工艺研发及应用
Process research and application of axial roof cutting technology of abrasive jet and fracture
夏永学 1张晨阳 1杜涛涛 1周金龙 1孙如达 1陆闯 1潘俊锋1
作者信息
- 1. 中煤科工开采研究院有限公司,北京 100013;天地科技股份有限公司开采设计事业部,北京 100013
- 折叠
摘要
厚硬顶板大面积悬顶是诱发冲击地压的重要原因之一,针对顶板深孔爆破和常规水力压裂存在的不足,开发了磨砂射流轴向切顶技术.该技术通过在巷道顶板钻孔内实施预制轴向裂缝、定向水力压裂等工序,使巷道走向和倾向方向上均形成最有利于顶板垮落的人造裂缝网,以实现最佳卸压效果.现场应用表明,实施磨砂射流轴向切顶后,目标岩层电磁波吸收系数增强,顶板裂隙明显增加;工作面回采期间,压裂影响区域的支架支撑力在增加,支架主要受力模式从降阻型和恒阻型转变为增阻型,微震能量释放更平稳,有效降低了冲击地压发生风险.在此基础上,分析了磨砂射流轴向切顶卸压防冲机理,即轴向切顶使工作面端头附近形成预制的轴向裂缝,工作面回采期间,顶板沿预制裂缝定向切落,降低了顶板弯曲弹性能转化为巷道围岩压缩弹性能的基础静载Ej和顶板突然断裂产生的强烈附加动载Ed,使巷道围岩不具备冲击启动的载荷条件.
Abstract
The large area overhanging of thick and hard roof is one of the critical reasons for inducing coal burst.Because of the shortcomings of deep borehole blasting and conventional hydraulic fracturing for the overhanging roof,the axial roof cutting technology of abrasive jet was developed.This technology achieves the best pressure relief by implementing prefabricated axial fractures and directional hydraulic fracturing in the roadway roof borehole to create an artificial frac-ture network in the roadway direction and tendency direction that is most conducive to roof collapse.The field application shows that the electromagnetic wave absorption ability of the stratum was enhanced,and the apparent resistivity was in-creased after the axial cutting roof technology of abrasive jet was implemented.During the mining operation of working face,the stress condition of the support was improved,and the release of micro-seismic energy was more stable,effect-ively reducing the risk of coal burst.On the basis of site observation,the mechanism of coal burst prevention by axial roof cutting of abrasive jet was revealed,that is,the plate-like structure fixed on both sides near the working face end is dam-aged by axial roof cutting,reducing the basic static load Ej,which is converted from the bending elastic energy of roof in-to the compression elastic energy of roadway surrounding rock,and reducing the strong additional dynamic load Ed,which is generated by the sudden fracture of roof,so that the roadway surrounding rock does not have the loading conditions for starting coal burst.
关键词
冲击地压/水射流/坚硬顶板/轴向切顶/卸压效果Key words
coal burst/waterjet/hard roof/axial roof cutting/pressure relief effect引用本文复制引用
基金项目
国家自然科学基金资助项目(52174118)
国家自然科学基金国家重大科研仪器研制资助项目(51927807)
中国煤炭科工集团股份有限公司重点资助项目(2021-TD-ZD007)
出版年
2024
NETL
NSTL
万方数据