基于静态压裂的瓦斯排放钻孔间距的数值模拟

Numerical simulation of spacing of gas drainage boreholes based on static fracturing

利用静态压裂钻孔,可以有效促进孔壁周围煤体裂隙发育,解决低透气性煤层瓦斯排放效率低、工程量大的问题。针对钱家营矿-600m7煤层,通过数值模拟研究其静态压裂过程中煤体破裂范围,确定了最优的瓦斯排放钻孔间距。研究结果表明:静态压裂影响范围分为破损区和弹性区,其中破损区范围约为压裂孔直径的2倍,而弹性区的形成主要决定因素为应力强度;静态压裂孔与排放孔的最优孔间距为6~8m。通过静态压裂技术可有效降低掘进工作面排放钻孔数量,减少施工量和作业时间,提高瓦斯排放效率。

The use of static fracturing can effectively promote coal seam fracture development around the hole wall could solve the low efficiency of gas drainage in the low penetrability coal seam and the problem of huge construction quantities. Through numerical simulation of static fracturing process of coal rupture range,the authors determine the optimal gas drainage horehole spacing in -600m 7^th coal seam of Qianjiaying mine. The results show that the influence scope of static blasting is the damage area and the elastic area;the damage area is about 2 times the diameter of the blasting hole,and stress intensity is a major determinant of the range of elasticity, finally the authors get the optimal hole spacing between the static fracturing hole and the discharge hole which is 6-8m;by the static fracturing technology,it can effectively reduce the number of drilling holes, reduce the amount of construction and operation time, and improve the efficiency of gas drainage.