Status of (sub-) joint industry project on rapid inversion of deep-sensing EM borehole measurements (Vladimir Druskin, Worcester Polytechnic Institute)


Vladimir Druskin from Worcester Polytechnic Institute


Sofia Davydycheva, Carlos Torres-Verdin, Frank Antonsen, Junsheng Hou, Mikhail Rabinovich, Wardana Saputra


We describe the current progress in 3D EM modeling and discuss our future activities in modeling and inversion of ultra-deep azimuthal resistivity (UDAR) logging tool responses. We developed a 3D anisotropic electromagnetic (EM) modeling software based on direct and iterative solvers. The designed in-house finite-volume (FV) homogenization technique and optimal gridding procedure allow the use of global model grid with inputs from commonly employed formation model formats, and derivation of independent finite-volume grids in tool coordinates. All that results in the fast and robust simulation of UDAR profiling along arbitrary well trajectories. Benchmarks and examples of UDAR simulations on operator’s models confirm the efficacy of our approach. Our future activities include novel approach to 2.5D simulator with 3D full anisotropy tensor allowing more accurate approximation of 3D models via adaptive upscaling and efficient 2D&3D inversion algorithms with curtain nonlinear preconditioning specifically designed for UDAR tool setups.


Research Professor at Worcester Polytechnic Institute, Fellow of Society of Industrial and Applied Mathematics, Formely Scietific Advisor at Schlumbrger-Doll Research