顺层钻孔瓦斯抽采钻孔合理布置的参数计算

Study on rational arrangement of gas drainage boreholes along coal seam

钻孔有效抽采影响半径是确定钻孔布置参数以及预测瓦斯抽采消突时间的重要依据。确定顺层瓦斯抽采钻孔合理布置参数,采用数值计算的方式,对不同抽采时间下顺层钻孔瓦斯抽采有效影响半径进行计算,并现场考察验证。研究结果表明:相同抽采条件下,抽采钻孔直径为75 mm,抽采时间为120 d时,抽采影响半径达到了1.0 m;抽采时间为60 d时,抽采影响半径达到了0.5 m,与数值计算结果基本相同。在实际工作中应日常性收集煤层瓦斯赋存、瓦斯涌出等相关资料;经常分析瓦斯地质变化情况,在地质构造带或局部瓦斯富集区或煤厚变化地带进行采掘活动时,应采取安全技术措施。

The effective radius of gas extraction borehole is an important basis for determining the parameters of borehole layout and predicting the time of gas extraction and outburst elimination.In order to determine the reasonable parameters of gas extraction borehole along seam,by using numerical calculation method,the effective radius of gas extraction borehole along seam under different extraction time was calculated.The field investigation results show that under the same extraction conditions,when the drilling diameter is 75 mm,the influence radius of the extraction reaches 1.0 m when the extraction time is 120 d,and 0.5 m when the extraction time is 60 d,which is basically the same as the numerical calculation results.In the actual work,the coal seam gas occurrence,gas emission and gas geological conditions should be analyzed,and safety technical measures should be carried out during mining in geological structural zones,local gas enrichment zones or coal thickness change zones.