Details of the abstract
| Title of paper | True 3D Land CSAMT Modeling |
| List of authors | Soyer, W., Mackie, R.L. |
| Affiliation(s) | CGG Multiphysics, Milan, Italy |
| Summary |
Controlled source audio magnetotellurics “CSAMT” is a grounded electromagnetic imaging technique used primarily in the mining industry and is a closely related predecessor to the marine controlled source electromagnetic method “CSEM” more familiar to the oil and gas community. Both methods involve injecting alternating electric current into the Earth through long transmitter dipoles, and making measurements of the Earth’s response at an array of EM receivers. Historically, CSAMT data have been interpreted using readily available MT modeling algorithms, but this means using only the data considered far enough away from the dipole source to be interpretable using the MT-inherent assumption of a uniform, or “far-field”, source. In this work, we show the advantages of carrying out complete earth, three-dimensional modeling of all grounded dipole EM fields, including those near the source, and avoiding the commonly employed, ad-hoc methods that throw away otherwise valuable “transition-zone” data that are unusable in MT-only modeling workflows. The CSEM inversion modeling is applied to a synthetic and a real data example, and inversion of complex field amplitudes is compared with impedance inversions. |
| Session Keyword | 2.0 Theory, Modelling and Inversion |
| File upload |
2.0_true_3d_land_csamt_modeli_soyer_02.pdf
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