| 摘要 |
<p>In accordance with illustrative embodiments of the present invention, techniques for determining certain formation characteristics in shaly sands are disclosed. In one embodiment, porosity data derived from sonic, neutron and formation density logging tools are combined with noninvaded zone resistivity data and various "assumed value" parameters to produce computed indications of shale or clay content, total and effective, nonclay filled porosity, hydrocarbon and water saturation, and formation pressure. In other embodiments, porosity data from only two of the three porosity tools can be combined with resistivity data and "assumed value" parameters to produce the computed indications. In all embodiments, the computed indications are tested for feasibility, and if not feasible, certain ones of the "assumed value" parameters are adjusted to make the computed indication feasible. Additionally, spontaneous potential, natural gamma ray, and borehole diameter data may be used to inhibit the computations under certain borehole and formation conditions.</p> |
