低渗透性煤层气液两相压注复合增透技术研究及应用

Research and Application of Gas-liquid Two-phase Pressure Injection Compound Anti-reflection Technology for Low Permeability Coal Seam

针对骆驼山煤矿低透气性煤层水力压裂后期钻孔瓦斯抽采衰减严重的问题,提出气液两相压注协同增透技术,现场试验表明:气液两相压注增透技术流量平均值是原有水力压裂技术的1.24倍,是单一空气压注钻孔的6.17倍,且流量衰减仅为原有水力压裂技术的64%,是单一空气压注钻孔的45%。对比原有水力压裂技术,气液两相压注增透技术协同增透效果明显,酸化压裂与注气增流相互促进,煤体内裂隙网络的连通性和注气增流作用影响范围都得到进一步的增强,保障矿井安全高效生产。

Aiming at the problem of serious attenuation of borehole gas extraction in the later stage of hydraulic fracturing in the low permeability coal seam of Luotuoshan coal mine,a gas-liquid two-phase pressure injection synergistic permeability enhancement technology was proposed,and the field test showed that the average flow rate of gas-liquid two-phase pressure injection permeability enhancement technology was 1.24 times that of the original hydraulic fracturing technology,6.17 times that of a single air pressure injection borehole,and the flow attenuation was only 64%of the original hydraulic fracturing technology and 45%of that of a single air pressure injection borehole.Compared with the original hydraulic fracturing technology,the synergistic permeability enhancement effect of gas-liquid two-phase pressure injection permeability enhancement technology is obvious,acidizing fracturing and gas injection increase promote each other,and the connectivity of the fracture network in the coal body and the influence range of gas injection and flow enhancement are further enhanced,so as to ensure the safe and efficient production of the mine..