井下煤层气抽采随钻注浆护壁浆液渗流模型  

Slurry seepage model of grouting while drilling to protecting wall used in underground methane drainage

作　　者：路桂英[1,2] 韩旺[3] 

机构地区：[1]中国地质大学(武汉)机械与电子信息学院,湖北武汉430074 [2]中国地质大学(武汉)工程学院,湖北武汉430074 [3]北京大学湍流与复杂系统国家重点实验室,北京100871

出　　处：《煤炭学报》2013年第6期1050-1054,共5页Journal of China Coal Society

基　　金：国家自然科学基金青年基金资助项目(41002046)

摘　　要：针对随钻注浆护壁浆液渗流过程进行了数学建模,首先建立关于注浆压力、渗透半径和渗透时间关系的偏微分方程,确定了初始条件和边界条件;然后采用隐式差分法得到浆液渗流的有限差分方程;最后判断了方程近似解的收敛性和稳定性,并进行了模拟计算。研究结果表明,浆液压力P0>1.0 MPa时,浆液扩散效果较好,能够达到护壁作用,但P0>1.0 MPa后浆液扩散效果相差不大,这也说明决定浆液渗透效果的关键因素是煤层的渗透率。In terms of the diffusion process in grouting while drilling, a mathematical model for seepage diffusion was developed. Firstly partial differential equations were established regarding the relationship among the grouting pres- sure, penetration radius and penetration time, and the initial conditions and boundary conditions were determined. Sec- ondly, using implicit difference method, a slurry seepage finite difference equation was obtained. Finally, the conver- gence and stability of the approximate solution were assessed and the simulations were performed. The results show that when the slurry pressure P0 〉 1.0 MPa, the slurry diffusion effect is better and able to protect drillhole wall. However, there is a little difference after P0 〉 1.0 MPa. This also shows that the key factor that decides the slurry penetration effect is the permeability of the coal seam. The model developed can be used as a theoretical basis for grouting pressure and grouting quantity selection when grouting while drilling is needed in soft coal seams.

关 键 词：煤层气 随钻护壁 渗透注浆 隐式差分 松软煤层 

分 类 号：P618.11[天文地球—矿床学]