井地电法的准解析近似三维反演研究

摘要

3D inversion of borehole-surface electrical data for complex geo-electrical models is still a challenging problem in geophysical exploration. We have developed a program for3D inversion to borehole-surface electrical data based on the quasi-analytical approximation(QA) and re-weighted regularized conjugate gradient method (RRCG) algorithms using Visual Fortran 6.5. Application of the QA approximation to forward modeling and Frechet derivative computations speeds up the calculation dramatically. The trial calculation for synthetic data of theoretical model showed that the program is fast and highly precise.%研究复杂地电模型上的井地电法三维反演一直是一个具有挑战性的课题.本文在准解析近似和重加权正则化的共轭梯度法的基础上,用Visual Fortran6.5开发了井地电法三维准解析近似反演程序.反演过程中的正演和Frechet导数矩阵计算都应用准解析近似大大提高了计算的速度.通过理论模型的合成数据反演试算,说明基于准解析近似法和加权正则化的共轭梯度法的井地电法三维反演程序有着计算速度快,反演精度高等特点.