Measurement and inversion schemes for single borehole-to-surface electrical resistivity tomography surveys

Several measurement arrangements involving different electrode arrays are considered for the case of single borehole-to-surface ERT surveys. Synthetic data tests indicate that standard measuring and inversion techniques can result in reconstructed images that suffer from artefacts. Based on the measurement sensitivity analysis, we propose a modified inversion scheme that compensates for the symmetric sensitivity of the in-hole measurements and improves the quality of the image. The new scheme has been tested using both synthetic and field data. The best results were obtained using pole-dipole or dipole-dipole arrays. Finally, some recommendations are made to improve the efficiency of field measurement configurations.