The rules for reservoir differentiation using longitudinal and shear wave velocities
We present a new method for revealing zones where rocks do fulfill the known average time equation using acoustic log-data. Such rocks are shale-less fluid-saturated porous ones with solid matrix; they have a distinct correlation between porosity factor and permeability. The rule for separation is closeness (coincidences) in such zones of profiles of porosity parameters being calculated by longitudinal and shear waves velocities using given equations. Exceeding the porosity factor calculated from longitudinal wave velocities by that from shear wave velocities reflects a shale rate of a zone.