Joint inversion of induction and galvanic logging data in axisymmetric geological models

We have developed a computational algorithm for joint inversion of array induction and galvanic data in 2D models. It is based on a finite-difference solver and nonlinear minimization and is designed to develop realistic geoelectric models of complex fluid-saturated formations. The algorithm is tested and verified on noisy synthetic induction and galvanic data. The obtained 2D inversion results are compared with those corresponding to the traditional 1D radial approach. The developed algorithm was used to conduct joint 2D inversion of VEMKZ and BKZ logs from the Fedorovskoe and Vostochno-Surgutskoe oil fields in the E-W striking Ob' River area.