CCTEG Shenyang Research Institute
State Key Laboratory of Coal Mine Safety Technology

以液态CO2气爆能量的TNT当量转化为基础,利用LS-DYNA软件分析爆破参数(装液量、泄爆压力峰值、致裂孔径)和地应力作用对液态CO2相变致裂效果的影响程度,并开展液态CO2相变致裂工程试验。模拟结果表明,液态CO2相变致裂效果与装液量、泄爆压力峰值和致裂孔直径的变化呈正相关,与地应力呈负相关,并且装液量和致裂孔径的选取不宜过大;试验结果表明,煤层致裂有效半径的试验结果(3.62m)和模拟结果(3.47m)相接近,验证了爆破数值模型的可靠性。应用液态CO2相变致裂技术增透后,与致裂孔1m距离的观测孔透气性系数提高了34倍,与致裂孔2.5m距离的观测孔瓦斯涌出强度提高了3.23倍,衰减强度降低了87.93%,与致裂孔1~1.5m距离的观测孔平均瓦斯抽采浓度提高了64.38%。

Based on the TNT equivalent conversion of liquid CO gas burst energy, LS-DYNA software is used to analyze the influence of blasting parameters (load volume, peak pressure relief and fracture hole diameter) and the effect of geostress on liquid CO phase change fracturing, and to carry out the liquid CO phase change fracturing engineering tests. The simulation results show that the effect of liquid CO phase change fracturing is positively correlated with the changes of load volume, peak pressure relief and fracture hole diameter, and negatively correlated with the ground stress, and the load volume and fracture hole diameter should not be too large; the test results show that the effective fracture radius of the coal seam is close to that of the test results (3. 62 m) and simulation results (3. 47 m), which verifies the reliability of the numerical model of blasting. After the application of liquid CO phase change fracturing technology to increase the permeability, the permeability coefficient of the observation holes at a distance of 1m from the fracturing holes is increased by times, the gas outflow intensity of the observation holes at a distance of 2. 5 m from the fracturing holes is increased by 3. 23 times and the attenuation intensity is reduced by 87. 93%, and the average gas extraction concentration of the observation holes at a distance of 1~ 1. 5 m from the fracturing holes is increased by 64. 38%.

王岩.地应力作用下煤层液态CO2相变致裂效果研究[J].煤炭工程,2024,56(12):108-114.