瞬变电磁法超前预报全空间解释技术研究

摘要

Advanced detection of transient electromagnetic method (TEM) is one of the effective methods to forecast water inrush in coal mine,its data interpretation technique is an important component in theoretical system of Underground TEM.Theoretical basis of full-space data interpretation and accuracy of traditional method was analyzed from application conditions,and full-space interpretation technique was applied to process measured data in mine.The results show that apparent resistivity and depth calculated by full-space formula was a certain time of which were calculated by half-space formula.The relative errors of late apparent resistivity to real resistivity at various sampling time are more than 40％ in half-space,and the error range of half-space time depth conversion formula is from 45.50％ to 50.88％ using full-space all-time apparent resistivity formula and full-space time depth conversion formula as a standard.The biggest error of full-space late apparent resistivity to real value is less than 8.74％,and then the maximum error between calculated value of apparent depth and the standard value is only 3.97％.While whole-space apparent resistivity and time-depth conversion formulas are applied to mine water inrush advanced detection,it achieves satisfactory results.%瞬变电磁法超前预报技术是预测井下突水构造的有效方法之一,其资料解释方法为地下瞬变电磁法理论体系的重要组成部分.从应用的角度出发对全空间资料解释的理论基础及传统解释方法的精确性进行分析,进而将全空间解释方法应用于井下超前预报实测资料的处理.结果表明,全空间视电阻率和视深度为半空间的某一倍数.半空间晚期视电阻率值在各个采样时刻与真值的相对误差均大于40％,当以精确视电阻率公式和全空间深度公式为标准时,采用半空间深度公式计算误差范围为45.50％ ～50.88％.全空间晚期视电阻率与真值的误差小于8.74％,进而由此计算的深度与标准值的最大相对误差仅为3.97％.将全空间全区视电阻率公式和深度计算公式应用于矿井突水构造的超前探测,取得了令人满意的效果.