长期荷载作用下煤层渗透率演化规律的试验分析  

Experimental analysis of the evolution law of the coal seam gas permeability under long-term load

作　　者：许江[1,2] 叶桂兵[1,2] 刘东[1,2] 李波波[1,2] 程明俊[1,2] 

机构地区：[1]重庆大学煤矿灾害动力学与控制国家重点实验室,重庆400044 [2]重庆大学西南资源开发及环境灾害控制工程教育部重点实验室,重庆400044

出　　处：《重庆大学学报（自然科学版）》2013年第9期1-7,共7页Journal of Chongqing University

基　　金：国家科技重大专项资助项目(2011ZX05034-004);国家自然科学基金资助项目(50974141);国家重点基础研究发展计划(973计划)资助项目(2011CB201203)

摘　　要：利用三轴渗透装置开展了不同环境温度和不同有效应力条件下长期荷载作用前后含瓦斯煤的渗透率演化试验研究,并在此基础上分析了长期荷载作用前后煤样渗透率对有效应力以及环境温度的敏感性。研究结果表明:环境温度一定时,长期荷载作用前后含瓦斯煤渗透率都将随有效应力增加而降低,且其有效应力敏感性也降低,而当有效应力一定时,含瓦斯煤渗透率及其环境温度敏感性都将随着环境温度的增加而降低;长期荷载作用前后渗透率差在不同环境温度和不同有效应力条件下的变化也存在差异,体现出较强的热力流耦合效应;长期荷载作用前后,环境温度敏感性系数差将随有效应力的增加,先是增加然后减小,在有效应力为4.3 MPa左右变为负值,有效应力敏感性系数差将随环境温度的增加减小,在26℃左右以后变为负值。Gas-filled coal permeability evolution tests are carried out before and after the long-term load with temperature and effective stress changing by using the triaxial permeability equipment. Based on the experiments, temperature sensitivity coefficient and effective stress sensitivity coefficient of the permeability of the coal sample are analyzed before and after the long-term load. The experimental results are shown as follows：l） Before and after the long-term load, with the increase of effective stress, the permeability and effective stress sensitivity coefficient both decrease when the temperature keeps constant. At the same time, with the increase of temperature, the permeability and temperature sensitivity coefficient also decrease when the effective stress keeps constant; 2）The difference of the permeability between before and after long-term load is different with temperature and effective stress changing, and it reflects thermal-fluid-solid coupling effects3） Before and after the long-term load,the difference of temperature sensitivity coefficient first increases and then decreases with effective stress increasing, and it becomes negative when the effective stress is about 4.3 MPa. What＇s more,the difference of effective stress sensitivity coefficient will decrease with the temperature increasing,and become negative after 26℃.

关 键 词：渗透率 有效应力 敏感性分析 长期荷载 

分 类 号：TD713[矿业工程—矿井通风与安全]