摘要
割缝卸压增透作业过程中,如何确定合适的割缝钻孔间距是高效实施水力割缝技术的关键基础,研究表明瓦斯抽采出现安全隐患及成本浪费的重要原因是由于卸压抽采中不清楚割缝钻孔有效作用半径,这使得瓦斯防治工作存在极大的盲点,同时也造成不充分卸压或密集布置钻孔的情况。通过使用数值模拟结合现场实例验证的手段,对水力割缝工艺应用于低渗煤层卸压增透效果的影响因素进行了分析,结果表明:缝槽高度的变化对煤体卸压效果的影响不显著;当采取射流割缝技术后,对煤层局部保护层开采有所影响,从而增大了单孔塑性极限平衡区,则单孔瓦斯的释放程度也相应增大;针对煤体单排钻割卸压过程,在缝槽上方竖直方向卸压效果要优于水平方向上的卸压效果。通过分析钻割卸压增透影响因素及卸压机理,为割缝钻孔的布置提供理论上的指导。
During the phase of slotting pressure relief and permeability enhancement,the key foundation of efficient implementation of hydraulic slotting technology is:how to determine the appropriate slotting hole distance.Previous studies show that the hidden danger and the waste in gas extraction are mainly due to the unclear the effective action radius of slotted drilling in pressure relief extraction,which makes the prevention and control work have the blind spot and causes insufficient pressure relief or dense drilling arrangement.In this paper,numerical simulation combined with field examples are used to verify the method.The influence factors of hydraulic slotting technology applied in pressure relief and permeability enhancement of low permeability coal seam were analyzed,the results showed that:the change of slot height has no significant effect on the pressure relief effect;when jet cutting technology is adopted,it will affect the local protective layer,thus increasing the plastic limit equilibrium area and the gas release degree accordingly;through the pressure relief process of single row drilling in coal,the release effect in vertical direction above the slot is better than that in horizontal direction.This paper analyses the influencing factors and mechanism of pressure relief and permeability enhancement in drilling which provides theoretical guidance for the layout of slotted boreholes.
作者
胡雷
陈柯宏
谯石
蒋志刚
HU Lei;CHEN Kehong;QIAO Shi;JIANG Zhigang(Xinwei Coal,Sichuan Goal Group Furong Company,Yibin 644500,China;Coal Management Section,Yibin Emergency Management Bureau of Sichuan Province,Yibin 644500,China;Sichuan Coal Industry Group Limited Liability Company,Chengdu 610091,China)
出处
《煤矿爆破》
2019年第5期13-19,共7页
Coal Mine Blasting
关键词
数值模拟
钻割卸压
影响因素分析
地应力
numerical simulation
drilling and cutting pressure relief
influence factors analysis
in-situ stress
