液态CO_2相变致裂增透技术在高瓦斯低透煤层的应用

Application of permecbility improvment technology with liquid CO_2 phase transition fracturing to high gassy and low permeability seam

针对平煤十三矿煤层的高瓦斯低透气性现状,为了提高矿井的瓦斯抽采量,采用了液态CO_2相变致裂技术进行强化抽采,试验研究了液态CO_2相变致裂技术在高瓦斯低透气性煤层中的增透机理和消突增透效果。通过对己15.17-11111运输巷底抽巷采取液态CO_2相变致裂技术,利用专门的液态CO_2相变致裂装置,在穿层钻孔中致裂爆破,可以使周围煤体产生裂隙,煤层透气性系数增大,试验结果表明:单孔瓦斯平均抽采体积分数是试验前的1.42倍,单孔瓦斯日平均抽采纯量是试验前的2.17倍,抽采衰减周期至少延长2倍以上,可有效提高煤层瓦斯预抽效果。

According to the high gassy low permeability status of the seam in No. 13 Mine of Pingdingshan Tian＇an Coal Company and in order to improve the gas drainage volume of the mine,the liquid CO2 phase transition fracturing technology was applied to the enhanced gas drainage. The experiment study was conducted on the permeability improved mechanism and the outburst elimination and permeability improved effect of the liquid CO2 phase transition fracturing technology in the high gassy and low permeability seam. With the liquid CO2 phase transition fracturing technology applied to the floor drainage gateway of the Ji15.17- 11111 transportation roadway,the special liquid CO2 phase transition fracturing device applied could make a fracturing explosion during the bed crossing borehole,could make the cracks around the coal mass,could make the permeability coefficient increased of the seam.The experiment result showed that,the average drainage concentration from a single gas borehole was 1.42 times higher than before the experiment. A daily average drainage pure volume from a single gas borehole was 2.17 times higher than before the experiment. The attenuation period of the gas drainage was expanded over two times at least and the pre-drainage effect of the seam gas could be effectively improved.