强突出煤层“内保护层”构建理论及工程实践

Theory and engineering practice of constructing“inner protection layer”for strongly prominent coal seams

保护层开采是煤矿瓦斯灾害防治最有效的技术手段,适用于有保护层可采的多煤层(群)等。对于无保护层可采的强突出单一煤层,随着采深加大、开采强度增加、构造更加复杂等多重因素叠加影响,应力与瓦斯耦合型灾害成为主导。为消除煤与瓦斯突出危险,目前采取的诸如机械扩孔、水力冲孔、水射流割缝和水力压裂等措施均能较好地提高抽采效果,但未能实现均匀卸压、均匀增透和消除应力异常,存在一定的消突局限性。如何实现瓦斯高效抽采和高效消突是长期遏制该类煤层安全高效开采的主要技术瓶颈。研究结合河南能源集团所属突出矿井“零距离保护层”分层开采、穿层钻孔卸压增透强化抽采消突的工程实践,通过优化穿层钻孔设计、合理选择卸压措施和精准计量掏出煤量,强化卸压消突效果考察,实现大区域连片均匀卸压,形成了在煤层内构建类似保护层的消突途径,提出了“构建内保护层技术”,实现了强力均匀卸压、高效抽采,实现煤层快速消突。总结以河南能源焦煤公司为代表的突出矿井瓦斯治理技术发展历史及经验,开展单一厚煤层“构建内保护层技术”研究,阐释了“构建内保护层”消突的科学内涵、消突机理构建方法,开发了内保护层消突效果评价技术,构建了强突出单一煤层内保护层消突技术体系并制定了相关企业标准。提出强突出单一煤层主动构建内保护层的消突理念,创新了保护层开采的内涵和外延,为强突出单一煤层高效消突提供了较完善的技术体系和较为坚实的理论基础及技术手段。

Protective layer mining is the most effective technical means to prevent and control coal mine gas disaster,which is applicable to multiple coal seams(groups)with protected seams available for mining.With the influence of multiple factors such as increasing min-ing depth,mining intensity and more complex tectonics,the stress and gas coupling type of disaster for a single strong protrusion coal seam without protective layer has become the dominant.In order to eliminate the risk of coal and gas protrusion,the current measures such as mechanical reaming,hydraulic punching,water jet cutting and hydraulic fracturing can better improve the extraction effect,but fail to achieve uniform pressure relief,uniform penetration and eliminate stress anomalies,there are certain limitations to the elimination of pro-trusion.How to achieve efficient gas extraction and high-efficiency outburst elimination is the main technical bottleneck that has long curbed the safe and efficient mining of this type of coal seam.The study combined the engineering practice of“zero-distance protective layer”stratified mining and unloading pressure and increasing penetration of penetrating boreholes to enhance the extraction and eliminate outburst in prominence mine belonging to Henan Energy Group.The effect of pressure-releasing enhancement and outburst elimination was investigated by optimizing the design of penetrating boreholes,reasonably selecting the pressure releasing measures and accurately metering the amount of coal hollowed out.The effect of pressure releasing to eliminate outburst was strengthened,the uniform pressure re-leasing in a large area was realized,and a way of eliminating outburst by constructing a similar protective layer in the coal seam was formed.The“construction of inner protective layer technology”was proposed to achieve strong and uniform pressure relief,efficient ex-traction and rapid outburst elimination in coal seam.Summarizing the development history and experience of gas management technology in protruding mines represented by Henan Energy Coking Coal Company,the research on the“construction of inner protective layer tech-nology”for single thick coal seam was carried out,the scientific connotation of“constructing inner protective layer”to eliminate outburst was explained,the mechanism of eliminating outburst was revealed,and the constructing method was formed.The effect evaluation tech-nology of inner protective layer to eliminate outburst was developed,a technology system for eliminating outburst in the inner protective layer of a single coal seam with strongly outburst was constructed,and the related enterprise standard was formulated.The proposed concept of actively constructing the inner protective layer to eliminate outburst in a single coal seam with strongly outburst has innovated the connotation and extension of protective layer mining,and provided a more complete technical system and a more solid theoretical basis and technical means for the efficient outburst elimination in a single coal seam with strongly outburst.