注气条件下煤层透气性系数的快速测定及其计算  

Rapid measurement and its calculation of coal seam permeability coefficient under the condition of gas injection

作　　者：李秉芮 李书波 刘娜[1] 陈凤梅 LI Bingrui;LI Shubo;LIU Na;CHEN Fengmei(College of Energy and Mining Engineering,Shandong University of Science and Technology,Qingdao 266590,China;College of Safety and Envi-ronmental Engineering,Shandong University of Science and Technology,Qingdao 266590,China)

机构地区：[1]山东科技大学安全与环境工程学院,山东青岛266590 [2]山东科技大学能源与矿业工程学院,山东青岛266590

出　　处：《煤炭学报》2021年第S01期274-280,共7页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(51674158,51804183)。

摘　　要：煤层透气性系数是评价瓦斯抽采效果的主要指标,也是评价煤层增透效果最直接的技术参数。针对煤层透气性系数原位测定时间长的问题,研究煤层透气性系数的快速测定方法以及与之相应的计算方法。基于“原位、密集、快速”的测定原则,开发了移动式煤层透气性系数快速测量仪,并提出了“顺层钻孔+移动式测量仪+注气”的测量方法。针对“注气”快速测定这一特定条件,以达西定律为基础构筑了煤层透气性系数反演计算方程,通过坐标变换,采用数学物理方法推导出了实际钻孔煤层透气性系数解析解表达式,确定了钻孔压力特征曲线方程。通过现场实测验证了煤层透气性系数快速测定方法的再现性,并与传统透气性系数计算方法进行了比较,结果表明:短时间的测定即可得到钻孔压力特征曲线的变化规律和基本特征,煤层透气性系数快速测定方法是可行的;同一钻孔同一测点重复测定的结果基本一致,具有良好的再现性,证明本文提出的快速测定方法是可靠的;实测钻孔压力曲线经过坐标变换得到的特征曲线是线性的,在形式上与本文推导的特征曲线方程完全一致,证明根据特征曲线求解煤层透气性系数是正确的;煤层透气性系数仅与钻孔压力特性曲线的斜率有关,计算简单;本方法与传统煤层透气性系数计算方法的计算结果基本一致,可以满足实际工程需要。The coal seam permeability coefficient is the main index to evaluate the effect of gas drainage,and also the most direct technical parameter to evaluate the effect of coal seam permeability.The rapid determination method of coal seam permeability coefficient and its corresponding calculation method were studied to solve the problem of its long measurement time.The mobile quick measuring instrument of the permeability coefficient of the coal seam was developed,and the measurement method of“drilling along the seam+mobile measuring instrument+gas injection”was proposed based on the principle of“in situ,dense,and fast”measurement.The inversion equation of the permeability coefficient of the coal seam was built based on the Darcy’s law for the specific condition of measurement by“gas injection”,and the analytic equation of permeability coefficient of the coal seam in actual drill hole with the mathematical and physical method was derived,and the characteristic curve equation of the drill hole pressure was determined.The reproducibility of the rapid measurement method of coal seam permeability coefficient was verified by field measurement,and compared with the traditional calculation method of permeability coefficient of the coal seam.The results show that the variation law and basic characteristics of borehole pressure characteristic curve can be obtained by short time measurement and the rapid measurement method of coal seam permeability coefficient is feasible.The results of repeated measurement of the same borehole and the same measuring point are basically the same,which has good reproducibility,and the rapid measurement method proposed in this paper is reliable.The characteristic curve obtained from the measured borehole pressure curve is linear through coordinate transformation,which is completely consistent with the characteristic curve equation derived in this paper,and it is correct to solve the permeability coefficient of coal seam according to the characteristic curve.The permeability coeffici

关 键 词：煤层透气性系数 快速测定 注气 特性曲线 解析解方程式 

分 类 号：P618.11[天文地球—矿床学]