摘要
陈清礼 ,杨中海 ,胡文宝 .有效的一维 MT直接反演新方法 .石油地球物理勘探 ,2 0 0 3,38(3) :32 4～ 32 7在大地电磁测深方法中 ,视电阻率反映在给定频率处穿透深度范围内的平均电阻率 ,不同频率的电磁波 ,其穿透深度不同。据此 ,利用等效电阻率的概念 ,设计了一个由视电阻率曲线直接计算地层电阻率的算法。该算法首先依据最高频率点的视电阻率确定表层电阻率并估算其厚度 ;然后由高频的视电阻率确定相应的并联等效层的电阻率和厚度 ;之后再由第一层的电阻率及厚度和等效层的电阻率及厚度计算第二层的电阻率及厚度 ;依次类推 ,从上到下计算出各电性层的参数。该算法不需要初始模型 ,也不必进行数据拟合。对不同模型的理论数据的反演均表明该方法在划分电性层时很有效 ,反演结果与实际模型对应较好。
At the given frequency,the apparent resistivity of magnetotelluric sounding (MT) reflects the average resistivity at the range of penetration depth of that frequency.The electro magnetic wave with different frequency has different penetration depth.The algorithm firstly determines the subsurface resistivity and evaluates their thickness depending on the maximum frequency point and apparent resistivety;then determines the resistivity and thickness of equivalent layer parallel connecting both first and second layer;after that,the algorithm determines the resistivity and thickness of second layer from that of first and equivalent layer;and so on,finally we got the parameters of each electric layer from top to bottom.The algorithm needs neither initial model nor data fitting.The inversion of theoretic data with different model showed that the method is effectiveness in dividing conductive formation.The inversion results and the real models matched well.
出处
《石油地球物理勘探》
EI
CSCD
北大核心
2003年第3期324-327,共4页
Oil Geophysical Prospecting
关键词
大地电磁测深方法
MT直接反演技术
等效电阻率
视电阻率
平均电阻率
电磁波
MT,MT direct inversion,equivalent resistivity,apparent resistivity Chen Qingli,Electro Magnetic Section,Department of Geophysics,Jianghan Petroleum Institute,Jingzhou City,Hubei Province,434102,China
