Electromagnetic methods are becoming increasingly important for hydrocarbon exploration. We have developed a 3D electromagnetic modeling tool targeted at simulations of the controlled-source electromagnetic surveys currently carried out by the industry. This tool allows testing electromagnetic responses for various reservoir scenarios. It is based on a finite-difference frequency-domain approach.

Features:

• output of all electromagnetic field components
• arbitrary source and receiver positions
• specific optimizations to improve the accuracy for sources and receivers near the seafloor
• tested for models that contain air
• efficient for multi-source modeling
• elementary sources: electric dipoles, magnetic loops
• combinations of source elements are possible
• MPI-parallelized, runs on Linux clusters

Example of the Ez component for a three-layer model, illustrating the accuracy at field discontinuities. Top: 3D Finite difference solution. Middle: reference solution from 1D reflectivity modeling. Bottom: ratio of the FD to reflectivity solution, showing high accuracy of both amplitude and phase.