多重水力割缝下煤层气储层卸压数值模拟

针对平顶山某煤矿深部煤层具有高地应力等特征,煤层气开采难度越来越大,煤层气储层卸压更是亟待解决,因此对水力割缝技术应用于深部本煤层卸压进行了数值模拟研究。计算了水力割缝最大切割深度,建立了水力割缝卸压三维应力场有限元模型,得到水力割缝后应力降大小及其影响范围。并对两水力割缝横向距离(5,6,7,8 m)进行数值模拟分析,得出割缝横向距离6 m应力降大小及其影响范围效果最好。进一步对平行与交错排列的多重水利割缝卸压情况进行数值模拟分析,得出了交错排列下多重水力割缝卸压效果较好,对实际深部煤矿下多重水力割缝布置的优化措施提供理论指导。

Numerical simulation for methane store pressure release in coalbed under mult-hydraulic cutting seam

Aiming at high stress characteristics in deep coal bed in the Pingdingshan,the methane exploitation is more and more difficult and methane reservoir releasing is urgently awaited to be solved.Therefore hydraulic cutting seam technique applied releasing on deep coalbed was studied by numerical simulation.Through calculating the maximum cutting depth of the hydraulic cutting seam,the paper established the finite element model of three-dimension stress field of hydraulic cutting seam releasing and got the stress drop size and sphere of in、uence after the hydraulic cutting seam at the two hydraulic distance(5m,6m,7m,8m),numerical simulation analysis is carried out and obtained the distance of 6m stress drop size and its influence effect the best.Furthermore,the numerical simulation analysis for parallel and staggered multiple hydraulic slotting distressed condition was carried out,the effect of releasing of staggered multiple hydraulic cutting seam is better than the other.The method can provide the theoretical guide for multiple hydraulic slotting configuration on the actual deep coalbed.