US Patent 7168310 Accuracy of shaly sand formation evaluation

A novel process and methodology in deterministic formation evaluation is provided. The formation evaluation results can accurately quantify formation attributes, such as clay-volume, clay-bound-water, effective-porosity and water saturation in shaly sands. Total-porosity is determined using porosity-logs, such as density, neutron and sonic logs. After clay-volume and total-porosity are determined, sand volume (quartz, feldspar, mica . . . ) is the remaining part in the bulk formation evaluated, see FIG. 5.