摘要
随着煤矿开采逐渐向深部延深,高强度开采瓦斯涌出量大,煤岩体高应力与瓦斯灾害呈相互耦合态势。针对深部矿井高强度开采面临的煤岩与瓦斯动力灾害治理难题,基于高压水射流割缝卸压原理,提出应力、瓦斯双重卸压的煤岩与瓦斯动力灾害水力化防治技术。通过理论分析与数值模拟方法,分析了超高压水射流割缝破煤机制,研究了煤层割缝卸压措施对区域内煤体应力及瓦斯的双重影响。研究结果表明:高压射流在煤层内部切割破坏了煤体完整性,减弱了煤体对上覆岩层支承能力,能有效地缓解割缝区域内应力集中;钻孔内部切割形成的缝槽改变钻孔瓦斯抽采模式,由径向流动改变为径向、轴向复合流动,使煤层瓦斯含量、压力迅速降低,超高压水力割缝技术通过应力卸压及瓦斯抽采2个方面解除了煤岩与瓦斯动力灾害发生危险。经在胡家河矿现场试验,割缝区域内平均微震事件能量下降18%、单位进尺微震能量降低37%,采用地音趋势法评估的矿压显现强烈次数下降17%,瓦斯抽采量提高4.1倍,表明超高压水力割缝技术能实现地应力及瓦斯压力双重卸压,有效解除煤岩与瓦斯动力灾害发生危险,为深部煤矿高强度安全开采提供技术保障。
With the gradual extension of coal mining to the deep,high-intensity mining gas surge volume is large,and the high stress of coal and rock and gas disasters are coupled with each other.Aiming at the coal rock and gas dynamic disaster control problem faced by high-intensity mining in deep mine,based on the principle of high-pressure water jet slotting pressure relief,the coal rock and gas dynam⁃ic disaster hydraulic control technology of stress and gas double pressure relief is proposed.Through theoretical analysis and numerical sim⁃ulation,the mechanism of ultra-high pressure water jet slotting is analyzed,and the double effects of ultra-high pressure water jet slotting on regional coal stress and gas drainage are studied.The results show that the ultra-high pressure water jet slotting inside the coal seam can effectively destroy the integrity of the coal seam,weaken the supporting capacity of the coal seam to the overlying strata,and effectively alleviate the stress concentration state in the slotting area;The seam groove formed by slotting inside the borehole changes the gas drainage mode of the borehole from radial flow to radial and axial compound flow,which makes the gas content and gas pressure in the coal seam de⁃crease rapidly.The ultra-high pressure hydraulic slotting technology reduces the risk of coal rock and gas dynamic disaster through stress relief and gas drainage.The field test in Hujiahe coal mine shows that the average Micro-seismic energy in the area of ultra-high pressure water jet slotting is reduced by 18%,the Micro-seismic energy per unit footage is reduced by 37%,the times of strong mine pressure be⁃havior assessed by the method of geostrophic trend is reduced by 17%,and the gas extraction rate is increased by 4.1 times.The research shows that the ultra-high pressure hydraulic slotting technology can effectively realize the double pressure relief of ground stress and gas pressure,effectively reduce the risk of coal rock and gas dynamic disaster and provide technical support for hi
作者
张永将
黄振飞
季飞
ZHANG Yongjiang;HUANG Zhenfei;JI Fei(China Coal Technology Engineering Group Chongqing Research Institute,Chongqing 400037,China;State Key Laboratory of the Gas Disaster Detecting,Preventing and Emergency Controlling,Chongqing 400037,China)
出处
《煤炭科学技术》
CAS
CSCD
北大核心
2021年第4期133-141,共9页
Coal Science and Technology
基金
中煤科工集团重庆研究院有限公司一般资助项目(2020YBXM22,2020YBXM23)。
关键词
煤岩与瓦斯动力灾害
水力割缝
应力卸压
瓦斯压力
coal rock and gas dynamic disaster
water jet slotting
stress relief
gas pressure