Abstract

Accurately delineating the thickness and extent of reservoirs is a major challenge for reliable reserves estimates and optimal well placement.

Originally pioneered through research at BP and Amoco, spectral decomposition is a recent seismic imaging innovation that provides interpreters with high-resolution reservoir detail. Detailed views of reservoir stratigraphy and thickness are revealed by extracting frequency-specific phase and amplitude from the seismic data. Spectral decomposition studies are used to improve reservoir delineation, primarily in clastic fluvial environments but also for carbonate environments.

This paper begins with a short review of spectral decomposition theory, where conventional time domain seismic data is analyzed according to its frequency content. Interactive animation workflows are then applied to search for thin bed information well beyond the conventional ?/4 thickness resolution determined from the wavelength of the dominant frequency of the seismic data. A spectral decomposition case study carried out in the Asia - Pacific is reviewed to define a clastic channel system where spectral decomposition has been found to be effective, and to provide guidelines for the factors that determine success when using spectral decomposition in this region.