矿井瞬变电磁多匝回线电感影响消除及曲线偏移研究  

Research on inductance effect removing and curve offset for mine TEM with multi small loops

作　　者：范涛 赵兆 吴海 鲁晶津 王继矿 

机构地区：[1]中国煤炭科工集团西安研究院有限公司,陕西西安710077

出　　处：《煤炭学报》2014年第5期932-940,共9页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(41104087);"十二五"国家科技重大专项资助项目(2011ZX05040-002);"十二五"国家科技支撑计划资助项目(2012BAK04B04)

摘　　要：小线框瞬变电磁近年广泛用于煤矿井下水害探测,但多匝回线自感和互感作用使早期时间道信号严重失真,小边长线框的固有过渡过程使晚期时间道信号显著抬升,均会对资料的处理解释精度带来干扰,为解决这一问题,通过分析矿井与地面瞬变电磁曲线的差异,分两步给出了消除小线框影响的方法。结合理论推导得出的多匝回线电感公式与实测电流-时间导数的关系,计算出需要消除的电感电动势,可消除早期信号中的小线框电感影响;引入曲线偏移概念,利用衰减曲线斜率与时间项指数幂项的相关性,以正演曲线为拟合目标,可在一定程度上修正晚期信号受到的线框固有过渡过程影响。通过对大量不同类型的矿井水害探测实测资料处理,结合钻探等其他实际地质信息,证明该方法可有效获取有利于精确反演解释的数据,使矿井瞬变电磁数据处理不再需要引入经验参数。Small loops TEM method is widely used for water detection in underground coal mine in the past few years. However, the self and mutual inductance effect of multiloops distorts the early time channel very badly, and the instinct transition area of small sidelength loop upraises the signal of late time channel, both of which will disturb the accuracy of data processing and interpretation. In order to solve those problems, two steps were gave to eliminate the effect of small loops by analyzing the difference between underground mine TEM curves and ground TEM curves. Com bining the relationship between inductance formula of multiloops by analytical derivation and derivative of current time by actual measurement, the effect of small loop on early signals was removed by calculating the inductance elec trodynamic potential that should be eliminated. Introducing the definition of curve offset, utilizing the relativity between the slope of attenuation curve and the exponent term of time, taking forward modeling curve as the fitting target, the in fluence of loop＇ s instinct transition area on late signal was corrected in a certain extent. By processing of a large amount of practical data from different types of mine water detection and comparing with other actual geology informa tion from drilling exploration, the method is proved to be effective for achieving good data for accurate inversion and interpretation. It permits no more introducing of experimental parameters into the processing of mine TEM data.

关 键 词：矿井瞬变电磁 线圈电感 曲线偏移 正演拟合 煤矿水害 

分 类 号：P631[天文地球—地质矿产勘探]