This work presents two contributions of the magnetoteluric method (MT) to the
petroleum exploration in a sedimentary environment intruded by diabase sills, where the
seismic imaging presents serious difficulties. The first contribution includes MT modeling of
geological unities presenting different resistivities while the second contribution is an analysis
of the effect of the magnetic permeability.
The MT modeling aimed at computing the MT response of two known geological
models along a profile across the São Mateus's Petroliferous Province, Solimões Basin. It
came out that the presence of sills affects the apparent resistivity and the phase in both TE and
TM modes, but does not preludes deeper investigation depths, which might even reach the
basement. Besides, different sill models present different answers, indicating that their
distinction is possible.
Finally, the inherent magnetic effect of the diabase, usually not considered in the
MT modeling, has been calculated and analyzed, showing that it also allows furthering the
investigation depth up to the basement, helping, in this way to estimate its topography.
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