Numerical analysis of multicomponent responses of surface-hole transient electromagnetic method

Numerical analysis of multicomponent responses of surface-hole transient electromagnetic method

Meng Qing-Xin;Hu Xiang-Yun;Pan He-Ping;Zhou Feng

【期刊名称】《应用地球物理（英文版）》 【年(卷),期】2017(014)001

【摘要】We calculate the multicomponent responses of surface-hole transient electromagnetic method.The methods and models are unsuitable as geoelectric models of conductive surrounding rocks because they are based on regular local targets.We also propose a calculation and analysis scheme based on numerical simulations of the subsurface transient electromagnetic fields.In the modeling of the electromagnetic fields,the forward modeling simulations are performed by using the finite-difference time-domain method and the discrete image method,which combines the Gaver-Stehfest inverse Laplace transform with the Prony method to solve the initial electromagnetic fields.The precision in the iterative computations is ensured by using the transmission boundary conditions.For the response analysis,we customize geoelectric models consisting of near-borehole targets and conductive wall rocks and implement forward modeling simulations.The observed electric fields are converted into induced electromotive force responses using multicomponent observation devices.By comparing the transient electric fields and multicomponent responses under different