立井揭煤前测定煤层瓦斯压力的方法与实践

发布时间：2018-04-03 10:43

本文选题：安全工程　切入点：井筒揭煤　出处：《安全与环境学报》2017年02期

【摘要】：为了解决复杂环境下立井揭煤前煤层瓦斯压力的可靠测定,基于揭煤井筒瓦斯地质特征、煤岩体物理力学性质,应用COMSOL软件模拟揭煤工作面在接近目标煤层时,井筒周围煤岩的地应力分布特征,直观展现了目标煤层中的应力分布结果。模拟结果表明,立井工作面距煤层的垂直距离为7 m时,煤层中会形成一个近似于环形的卸压圈,卸压半径为16 m,因此煤层瓦斯压力测试孔的终孔位置应布置在井筒中心线16 m以外的原始地应力区,以保证测压点瓦斯压力不受揭煤井筒卸压区的影响,令测压结果准确可靠,从而更好地预测煤与瓦斯突出区域的危险性。同时,结合立井揭煤工作面的水文地质特征和井筒严重淋水情况,自主研发并应用了瓦斯测压孔"两堵一注"封孔材料及特定的封孔工艺,进一步保障了封孔质量和瓦斯压力测试结果的可靠性。最后,依据测压结束时测压管内的实际水压情况,对测压结果进行修正,并依据实测瓦斯含量,采用间接法对所测得的瓦斯压力进行验证,实测值在反算得到的瓦斯压力值域内,表明此方法有效可行。
[Abstract]:In order to solve the problem of reliable measurement of gas pressure in coal seam before coal mining in a complex environment, based on the gas geological characteristics of coal shafts and the physical and mechanical properties of coal and rock mass, COMSOL software is used to simulate the coal face near the target coal seam.The stress distribution characteristics of coal and rock around the wellbore show the stress distribution results in the target coal seam intuitively.The simulation results show that when the vertical distance from the vertical face to the coal seam is 7 m, a pressure relief ring similar to the ring will be formed in the coal seam.The pressure relief radius is 16 m, so the final hole location of the gas pressure test hole in coal seam should be arranged in the original ground stress area beyond 16 m in the center line of the well bore, so as to ensure that the gas pressure at the pressure measuring point is not affected by the pressure relief area of the exposed coal wellbore, so that the pressure measurement results are accurate and reliable.In order to predict the danger of coal and gas outburst area better.At the same time, according to the hydrogeological characteristics of the coal face and the serious water leaching in the shaft, the sealing material of gas pressure hole "two blocks and one injection" and the special sealing technology are developed and applied independently.The reliability of the test results of sealing hole quality and gas pressure is further guaranteed.Finally, according to the actual water pressure in the pressure measuring pipe at the end of the pressure measurement, the results of the pressure measurement are revised, and the measured gas pressure is verified by indirect method according to the measured gas content.The measured values in the back-calculated gas pressure range show that this method is effective and feasible.
【作者单位】：河南理工大学安全科学与工程学院;瓦斯地质与瓦斯治理国家重点实验室培育基地;中原经济区煤层/页岩气河南省协同创新中心;
【基金】：国家自然科学基金项目(41372159) 企业委托项目:低渗煤层改性瓦斯高效抽采集成技术开发
【分类号】：TD712

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