童亭煤矿钻探取心施工方法

Core drilling in Tongting coal mine

通过介绍和分析安徽省童亭煤矿采空区的各段地层特性、岩性特征,指出了钻进和取心过程中的控制难点,采用了加大孔径结构、优化钻具组合及强化泥浆性能维护等技术措施;针对极其严重的缩径现象,采用大开小下的方法,克服了缩径造成的套管下放难题;采用加稠水泥浆灌注方法成功处理了114mm套管在采空区段断裂问题和地层严重破碎、漏水问题,最终顺利完成了7个煤系地层钻孔施工,取得了良好的经济社会效益。

By introducing and analyzing the characteristics of strata and lithology in the goaf area of the various sections of the Tongting coal mine in Anhui Province,the difficulties are pointed out in the process of drilling and coring.The relevant technical measures such as enlarging the borehole structure,optimizing the drilling tool combination,strengthening the mud performance maintenance were adopted.To deal with serious wellbore shrinkage,the borehole diameter was increased with reduced casing diameter to overcome the difficulties caused by shrinkage when lowering casing.Thickened cement grout was successfully used to deal with breakage of the 114mm casing,serious stratum fractures and water leakage problems in the goaf.Finally seven boreholes were successfully completed in coal strata,which achieved good economic and social benefits.