Abstract：Long-offset transient electromagnetic sounding is a new technique in electric survey. Its research and application in China are only in initial phase,and its processing and interpretation are only qualitative. In order to achieve efficient processing and quantitative interpretation of volumed transient electromagnetic data in time domain,we develop a practical method for data processing and interpretation which includes four steps:·Time-dependent vertical component of magnetic field is obtained by integrating an induced electromotance curve derived from dense sampling.·All-time magnetic field apparent resistivity is defined by using the vertical component of and then the apparent resistivity curve is calculated by taking numerical iterative method.·The resultant all-time resistivi4y is transformed froth time domain to frequency domain.·The inversion of transformed apparent resistivities is achieved finally by in-troducing MT inversion method.Modeling computation testifies that the technique desirably avoids mufti-solution,achieves reasonable all-time interpretation,and offers improved accuracy and field interpretation ability.
严良俊, 胡文宝, 陈清礼, 胡家华. 长偏移距瞬变电磁测深的全区视电阻率求取及快速反演方法[J]. 石油地球物理勘探, 1999, 34(5): 532-538.
Yan Liangjun, Hu Wenbao, Chen Qingli, Hu Jiahua. The estimation and fast inversion of all-time apparent resistivities in long-offset transient electromagnetic sounding. OGP, 1999, 34(5): 532-538.
