Stratigraphic Modelling: The Next Generation

Linda S. Smith-Rouch, John M. Armentrout, Scott A. Bowman, Gary D. Harris

A new generation of stratigraphic modelling software, techniques, and strategies have improved our ability to constrain input parameter values, analyze geologic processes, predict lithofacies and estimate the volume of sediment bypass. Previous modelling efforts attempted to match a simulated profile to stratal geometries and sediment thicknesses defined by a geologic cross section or seismic profile. The first phase of our study of the Galveston-East Breaks region involved experiments in stratigraphic modelling that tested the depositional system's response to variations in subsidence rates, relative changes in sea level, sediment supply, and variable ratios of sand/shale and traction/suspension.

New options within PHIL and new modelling techniques better constrain ages for maximum flooding surfaces, refine paleowater depth profiles, evaluate subsidence rates, match simulated lithofacies to well logs, and identify high resolution prograding clinoforms. Recent modelling efforts have focused on the prediction of lithofacies and the amount of sediment bypass basinward of the modelled seismic profile. These simulation results are generally consistent with a seismic profile and well data located basinward of the Galveston-East Breaks line. The simulated sediment thickness from 3.8 to 1.6 Ma in the intrashelf basin was less than observed in the seismic profiles. A third seismic line that trends oblique to two dip-oriented lines was used to determine if this underfilled sect on is an artifact of a shift in sediment depocenter during that time.

AAPG Search and Discovery Article #91020©1995 AAPG Annual Convention, Houston, Texas, May 5-8, 1995