Abstract: Computer Simulation of Seismically-Defined Depositional Sequences: Pliocene and Pleistocene Geometry's and Rates, Offshore Texas

John M. Armentrout, Linda S. Rouch, Scott A. Bowman

Computer simulations based on integrated data sets enhance our understanding of depositional geometry's and facilitates quantification of depositional processes. A case study from the Pliocene-Pleistocene section of the South Galveston and East Breaks area integrates seismic reflection profiles, wireline logs, and biostratigraphic analyses as the control for both backstripping and forward modeling. This simulation project has been partitioned into four levels of analysis. Level I is the initial information retrieval from seismically constrained depositional geometry's calibrated by well data, and a sea level curve. The analysis provides estimates of subsidence rates and sediment flux rates. A critical element in this two-dimensional analysis is the location of shelf/slope breaks and t e gradients both landward and seaward of that position for each depositional cycle. Level II involves a series of comparisons between computer simulation models and the digitized seismic geometry's, rock types, and paleowater depths. This is an iterative phase facilitated by a graphics program that provides comparison of each iteration with the known stratigraphic framework. Based on the best-fit iteration, Level III quantifies and formats the iterative simulations into a data base for statistical computations. Level IV integrates the computer-simulated, quantitative and graphical data with previous biostratigraphic and seismic interpretations to evaluate the depositional processes and rates. Comparisons of predicted versus known lithofacies and biofacies at well locations provides a tes of the computer simulation and helps identify the most critical input parameters and program sensitivities.

AAPG Search and Discovery Article #90986©1994 AAPG Annual Convention, Denver, Colorado, June 12-15, 1994