The petrophysical analysis in this paper is based on dipole sonic (Vp and Vs), density, gamma-ray, and porosity (density porosity and neutron porosity) logs from wells in the White Rose oilfield, offshore Newfoundland. In general, Vp and Vs increase with depth, Vp/Vs decreases with depth, velocity increases as total porosity decreases, Vp/Vs decreases slightly when total porosity decreases, and Vs shows a high correlation with porosity.
We also applied empirical Castagna's (1985), Faust's (1951), Gardner et al.'s (1974) and Pickett's (1963) relationships. We find that Faust is the better predictor for Vp, Castagna is a better predictor for Vs, Castagna's limestone relationship works better than Pickett's limestone relationship, and the Gardner prediction of ρ should be used with caution.
Empirical relationships apply with a variable levels of accuracy. Better fits can be achieved by dividing the lithologies into formations (Jaramillo and Stewart, 2003).
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