2.5D resistivity inversion in anisotropic media: Numerical experiments

We present a set of 2.5D synthetic inversion experiments for a model comprising an isotropic block embedded within an anisotropic background. We examine and compare the image reconstructions obtained using the correct anisotropic code and those obtained using code based on the inappropriate but widely adopted isotropic assumption. Superior reconstruction in terms of reduced data misfit, true anomaly shape and position, and anisotropic background parameters were obtained when the correct anisotropic code was employed for media characterized by moderate to high coefficients of anisotropy. However, for low coefficient values, the isotropic inversion produced slightly better results because there are fewer parameters to determine. When an erroneous isotropic inversion is performed on medium to high level anisotropic data, the images are dominated by patterns of banded artefacts and high data misfits.