Applying statistical rock physics and seismic inversions to map lithofacies and pore fluid probabilities in a North Sea reservoir

Abstract

Reliably predicting lithologic and saturation heterogeneities is one of the key problems in reservoir characterization. In this study we show how statistical rock physics techniques combined with seismic information can be used to classify reservoir lithologies and pore fluids. One of the innovations was to use a new seismic impedance attribute (related to VP/VS ratio) that incorporates far-offset data, but at the same time can be practically obtained using normal incidence inversion algorithms. The methods were applied to a North Sea turbidite system. We incorporated well log measurements with calibration from core data to estimate the near and far-offset reflectivity and impedance attributes. Multivariate probability distributions were estimated from the data to identify the attribute clusters