New Petrophysical Models for Describing Pressure-dependent Acoustic Velocity and Absorption Coefficient in Porous Rocks

The pressure dependence of seismic velocity and absorption coefficient of acoustic waves in rock is an extensively explored rock physical problem. New petrophysical models are developed based on simple physical assumptions, through which relationships between velocity and pressure as well as absorption coefficient and pressure are set up and explained. The models are based on the idea that microcracks are opened and closed under pressure. The models were applied on acoustic velocity measurement data made on core samples and also seismic velocity and quality factor data set measured by Prasad (1997). The material parameters of the models are determined by using linearized inversion method. Laboratory measurements proved properly the accuracy of the new models.