Ultrasonic velocities in carbonates: laboratory data versus a new squirt-flow dispersion model

Understanding elastic properties of fluid saturated carbonates is a major challenge in quantitative interpretation of seismic data. In particular, the validity of Gassmann’s equations for carbonates is sometimes unclear. This complexity is belived to be caused by diversity of their pore geometries. One of the ways to study the impact of pore geometry is by measuring ultrasonic velocities. In this paper we compare the measured velocity as a function of pressure against a recently developed simple squirt flow model. This allows us to estimate effective aspect ratio of compliant pores. The resulting value of about 0.01 appears to be common for a number of samples examined.