Abstract

Numerical modeling of geological models was used to compare the resolution and effectiveness of 2D resistivity imaging survey with seven electrode arrays. The arrays used are the pole-dipole (PD), wenner-alpha(WN), wenner-schlumberger (WS), dipole-dipole (DD), wenner-beta (WB), wenner gamma (WG) and multiple gradient (MG). Three synthetic geological models that simulate a buried channel, claylens and sandlens were generated using RES2DMOD software. These models were contaminated with 5% noise level in order to simulate field data. The geological models were inverted using RES2DINV with robust inversion and smoothness-constrained least-squares techniques. The inverted results were examined for image resolution and anomaly effects (AE) were calculated to measure the effectiveness of these arrays. The inversion results showed that the robust inversion gives better imaging resolutions than the smoothness-constrained least-squares inversion. It was also observed that WS is the most effective for imaging a buried channel while DD is the most suitable array for claylens and sandlens. The calculatedAE for the different arrays vary with the geological models with DD having the highest value in almost all the models. However, the relative high AE does not coincide with good image resolution from the inversion.This study has determined the resolution and effectiveness of 2D resistivity imaging with seven electrode arrays in resolving three geological models that could be a guide for geophysical field investigation.