3-D Petrophysical Properties from Seismic Data

Abstract

This interpretation technique uses a seismic workstation to estimate combinations of rock types, porosities, fluids, and pressures from three-dimensional (3-D) seismic data. It displays the information as clouds in a 3-D volume. Data inputs are post- and prestack seismic attributes, and a combination of well-log curves. The display of petrophysical properties relative to the 3-D seismic structure allows a geoscientist to hypothesize a combination of petrophysical properties of a zone in the subsurface and observe the resulting spatial distribution of that combination in the 3-D survey volume. The spatial pattern changes as the geoscientist sweeps across a range of combinations of petrophysical properties. Clouds appear where the combination produces the observed responses of multiple seismic attributes. A data set from the Gulf of Mexico shows the applications of the technique to identify gas-saturated reservoirs.