From Bureau of Economic Geology, The University of Texas at Austin (www.beg.utexas.edu).
For more information, please contact the author.

AAPG Annual Convention, Calgary, Alberta, Canada, June 19–22, 2005

Seismic Geomorphology in Exploration and Development:
Workflows and Applications

Henry Posamentier and Lesli Wood

Abstract:

The application of seismic geomorphology to exploration and field development is a natural consequence of the advent of high-quality and increasingly more affordable and widespread 3D seismic data currently available. 3D seismic data affords plan view images of depositional elements and in some instances entire depositional systems. Analyses of such images can significantly enhance predictions of the spatial and temporal distribution of subsurface lithology (reservoir, source, and seal), compartmentalization, and stratigraphic trapping capabilities, as well as enhanced understanding of process sedimentology and sequence stratigraphy.

Typical seismic geomorphologic workflow involves 1) initial reconnaissance through 3D volumes using various slicing techniques using a variety of different seismic attribute volumes including full stack reflection amplitudes, near and far stacked amplitude volumes, and coherence volumes, as well as opacity rendering. The objective to this initial analysis is to identify features that have geologic or stratigraphic significance. 2) Such features are subsequently investigated further through a combination of detailed slicing, interval attributes, horizon picking and amplitude extraction, horizon illumination, etc. 3) Integration of seismic geomorphologic analyses with seismic stratigraphic analyses is a critical part of the workflow, whereby the plan view is integrated with the section view to ensure a consistent interpretation. Calibration and ground-truthing with well logs and core is essential at this stage.

Three dimensional images also readily lend themselves to quantitative assessment of geomorphic features. This approach lends credence to the more qualitative aspects of seismic geomorphologic analyses. Such attributes as channel sinuosity, slope, width:thickness ratios, as well as measures of channel bifurcation, internal architecture and distribution of architectural elements associated with carbonate build-ups can be readily measured.