Acoustic Logging Methods in Fractured and Porous Formations

Abstract

Formation fractures have significance effect on the permeability of rocks in oil and gas reservoirs. In real conditions, the opening of vertical fractures exceeds the opening of horizontal fractures and the permeability of reservoirs in conditions of horizontal wells is higher than in vertical conditions. In the sonic log longitudinal waves, unlike the transverse waves, the attenuation rate strongly depends on the wave path direction. It is shown that the mechanism of the attenuation of sound waves in porous rocks is represented by the scattering of "soft" microheterogeneous inclusions. For reservoir rocks with porosity (φ) of (10-20)%, the attenuation decrement is several times higher than the decrement of the other mechanisms.