地面钻井抽采卸压瓦斯的试验研究

Experimental Study on Pressure-relieved Gas Drainage and Extraction by Surface Boreholes

为缩短瓦斯抽采工程工期、降低瓦斯治理成本,高效抽采上被保护层的卸压瓦斯,在淮北芦岭煤矿开展了地面钻井抽采卸压瓦斯的工程应用试验研究。论述了地面钻井抽采卸压瓦斯的技术原理及抽采卸压瓦斯的地面钻井基本结构。根据试验结果,地面钻井共抽采10个月,累计抽采瓦斯量2.484Mm3。瓦斯抽采分为增长期、产气高峰期和衰减期3个阶段,其中,产气高峰期历时4个月,瓦斯抽采浓度为60%～90%,平均抽采量达10.6m3/min。配合其他抽采措施,对应中组煤的瓦斯抽采率达70.6%,残余瓦斯含量降为5.2m3/t,残余瓦斯压力降为0.53MPa,消除了中组煤的突出危险性。最后对地面钻井卸压瓦斯抽采效果的影响因素进行了分析。

Experimental and application study on pressure-relieved gas drainage and extraction by surface boreholes was carried out in Huaibei Luling Coal Mine in order to shorten the construction period of gas drainage and extraction,decrease the cost of gas control and efficiently drain pressure-relieved gas from the upper protected coal seam. This paper described the technological principle of pressure-relieved gas drainage and extraction by surface boreholes and the basic structure of the holes. According to experiment results,the total drainage volume of pressure-relieved gas by surface boreholes was 2.484Mm3 for 10-mouth gas drainage and extraction,of which,the peak drainage volume lasted 4 mouths,with the drained gas concentration 60%～90% and the average drainage volume of 10.6 m3/min. While other drainage methods were applied,the pressure-relieved gas drainage rate from the middle group coal seams reached 70.6%,the residual gas content decreased to 5.2m3/t and the pressure of the residual gas decreased to 0.53MPa,this thus eliminated the outburst risk of the middle group coal seams. Finally,the influence factors of pressure-relieved gas drainage by surface boreholes were analyzed.