Paper No. 112-3
Presentation Time: 2:00 PM-2:15 PM
3D GEOMETRIC MODELING OF SALT TECTONICS, SEDIMENT DISPERSAL PATHS, ACCUMULATION HISTORY, AND HYDROCARBON MIGRATION THROUGH TIME
RICHARDS, David R., GRIFFITHS, Paul, and BLAND, Stuart, Midland Valley Exploration, 14 Park Circus, Glasgow, G3 6AX, United Kingdom, david@mve.com

Progressive active salt diapir growth impacts sediment dispersal paths, accommodation space for marine deposits, and hydrocarbon migration routes. Forward modeling of the shape change of horizons through time, accompanying the salt body growth, provides insight into the interplay of structural development, sediment accumulation and hydrocarbon migration history. The forward modeling displays the sediment accumulation history of a reservoir unit in a particular time interval and subsequent potential hydrocarbon migration paths, as well as the strain history.

A case example in the vicinity of a complex salt body in the Gulf of Mexico, illustrates the concepts and techniques of the 3d modeling through time. The present day shape of several horizons and the salt are well defined by seismic data. Step-by-step restoration that includes decompaction, unfolding, and isostasy provides the basis for forward modeling.

Forward modeling of step-wise filling of accommodation space in a specific time interval shows the most likely channel paths of turbidite systems, and areas of ponded turbidite deposition. Reversing the restoration steps illustrates the sequence of deformation of the turbidite section resulting from salt withdrawal and lateral movement. For a time step when generation and migration of hydrocarbons was occurring, hydrocarbon migration pathways modeled onto the horizon tops illustrate the relative layout of the earlier deposition patterns compared with the later positions of structures that control migration routes. The combined restoration and forward modeling can thus provide valuable insight into the relative risk of potential hydrocarbon traps. Lastly, different strain values can be calculated for the horizon tops (or volumes) while deforming the surfaces from their initial, nearly flat geometry to their present day shape. These values can aid in understanding of fractures in the present day deformed state.

2002 Denver Annual Meeting (October 27-30, 2002)
Session No. 112
Forward Modeling in Tectonics and Structural Geology
Colorado Convention Center: C207
1:30 PM-5:30 PM, Monday, October 28, 2002
 

© Copyright 2002 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.