Carbonate rocks frequently exhibit velocity-porosity relationships less predictable than those found in siliciclastics because of complex and heterogeneous pore structures. Traditional pore-type classifications describe these pore structures but are inadequate for correlations to the rock's physical properties. In this preliminary research, velocity measurements of 20 core plugs of a Miocene carbonate platform in Central Luconia, Sarawak were made under dry-saturated condition at variable confining pressures and at effective pressures of 20MPa. The cross plot of measured velocity and porosity shows scattering along the Wyllie's time average equation. The large scattering in most cases will result in large uncertainties in seismic inversion and calculations of porosity volumes. Digital image analysis (DIA) of thin section images were used to derived quantitative pore geometric parameters. Four DIA parameters proved to best describe several aspects of the pore system: dominant size (DOMsize), perimeter over area (PoA), roundness (γ) and aspect ratio (AR). Combination of porosity, microporosity and these four geometric parameters improves coefficient of determination (R2) velocity estimation from 0.9219 to 0.9974. © Copyright 2011, International Petroleum Technology Conference