西山矿区煤层顺层孔CO_2爆破增透试验研究

Experimental Study on CO_2 Blasting of Bedding Hole in Xishan Coal-mining Area

为提高西山矿区煤层透气性,缩短瓦斯抽采达标时间,分析了煤层顺层孔CO_2预裂增透技术可行性,模拟了CO_2预裂增透半径。研究结果表明:CO_2爆生气体计算压力大于围岩作用下煤体强度,CO_2爆破煤层增透具备技术可行性;数值模拟显示,经过CO_2预裂爆破后,预裂效果最好的是屯兰矿2#煤,煤层裂隙半径4.20m,其次是屯兰矿8#煤,煤层裂隙半径3.90m,再次是马兰矿8#煤,煤层裂隙半径3.45m,最后是东曲矿8#煤,煤层裂隙半径3.30m;现场试验表明,东曲矿8#煤爆破孔间距按6.5m布置,压裂区平均单孔抽采纯流量是未压裂区的3.2倍。

In order to improve permeability of coal seam in Xishan mining area , shorten gas drainage standards time the feasibility of CO2 blasting pre splitting technology in coal seam was analysed; and the CO2 pre crack penetration radius was simulated. The results show that the CO2 detonation pressure was greater than the strength of coal within the surrounding rock, and coal seam permeability could be feasibly increased by using CO2 blasting ; simulations show that pre splitting effect of Tunlan 2# coal was the best, with fissured circle radius 4.20m, Tunlan 8# coal pre splitting radius 3.9Ore, and Malan 8# coal pre splitting splitting radius 3.30m; field test shows the average flow rate of single hole radius 3.45m, Dongqu 8# coal pre drainage in fractured zone was 3.2 times of that of non - fractured zone when the blasting holes of Dongqu 8# coal was placed at intervals of 6.5m.