The shear-wave velocity prediction for sedimentary rocks

Abstract

The shear-wave velocity is among the key petrophysical parameters required for reservoir characterization, seismic inversion, and geo-mechanical analysis. In areas where shear-wave velocity data are not available, the industry practice is to estimate shear-wave velocity empirically from compressional-wave velocity. However, many of the existing empirical relationships between shear and compressional velocities are lithology specific. The empirical relationships that work well for siliciclastic rocks may perform poorly in carbonate environments and vice versa. In this work, attempts are made to develop the new shear-wave prediction models that can be applied to a wide range of lithologies commonly found in sedimentary basins. In the new models, shear-wave velocity is expressed as a function of the compressional-wave velocity and the formation bulk density. The newly proposed models are validated using actual field data from the North Sea and the Niger Delta. The new models perform better when compared to the major existing correlations.