Figure 5. Theoretical velocities in water-filled porous media (without gas hydrate and free gas), obtained using core-measured porosity and density (from index properties). The downhole logging velocities (Paull, Matsumoto, Wallace, et al., 1996), the VSP-derived velocities (Holbrook et al., 1996), and the interval velocities derived from tomographic inversion of traveltimes are also plotted for comparison.