三维旋转水射流扩孔增透技术装备及应用

Technology and Equipment of Three Dimensional Rotation Water-jets Enlarging Bore to Improve Coal Seam Permeability

针对我国低透气性煤层抽采难题,研发出三维旋转水射流扩孔增透技术与装备。通过理论分析、数值模拟和现场试验研究发现:三维旋转水射流破煤以剪切破碎为主,合理布置扩孔钻孔可实现区域煤体整体卸压增透。潘四东矿井下试验结果显示,扩孔钻孔瓦斯抽采体积分数80.5%,纯瓦斯流量18.15 L/min,分别为常规钻孔的1.43倍,纯瓦斯流量为常规钻孔的1.72倍,提高72%,显著提高了低透气性煤层的抽采过程中的瓦斯浓度和抽采纯瓦斯流量,具有较好的增透效果,瓦斯抽采效果显著提高。

According to high gas extraction difficulty of the low permeability seam,a new technology of three dimensional rotation water-jets enlarging bore technology for seam permeability improvement was developed. With the theoretical analysis,numerical simulation and site tests,the study results showed that three dimensional rotation water-jets breaking coal was given priority to shear breakage,reasonably layout enlarging borehole can realize regional gas control. The underground test results of Pansidong Mine showed that gas concentration of enlarging borehole was 80. 5%,the flow of pure drilling gas was 18. 15 L / min,respectively 1. 43 times that the conventional drilling,pure gas flow rate is 1. 72 times that of the conventiond drilling,increa sed by 72%,the gas concentration and the flow of pure drilling gas were highly improved.