The Density-Neutron Method considers the clay present in the constitution of reservoir rocks, in order to produce realistic values for porosity. Often, this consideration is called as shale volume correction and adopts the premise that the clay present in the reservoir rock is the one constituting the adjacent shale, so that these clays share the same physical properties (density and neutron porosity) Geologically, this premise assumes a depositional continuity, which may not reflect the current condition of the sequence layers traversed by the well. This work adopts the ΦN x ΦD plot as reference to show a correction method, which no assumes the depositional continuity of shale and reservoir rocks and assumes as the physical properties of the clay in the reservoir rock, the average values of the physical properties of clays with greater occurrence in the oil field, as determined by sedimentological studies. This work presents an evaluation of this method using synthetic data generated by the petrophysical model and actual log data from one borehole drilled in the Namorado oil field, Campos Basin.
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