Influence of Basement Tectonics on Depositional Systems and Seismic Stratigraphy: ABSTRACT

Abstract

The new field of seismic stratigraphy has focused attention on the reconstruction of depositional models in which seismic responses can be evaluated and interpreted. In many exploration programs, geologists and geophysicists limit their work to processing data from relatively thin petroleum-productive sequences. Amplitude and other seismic anomalies and porosity variations are studied in search for the elusive stratigraphic trap without concern for what geologic conditions are present at the deeper basement level. Current research in oil-productive basins indicates that recurrent movement on basement fault systems during deposition may have had an important influence on the distribution of reservoir rock, on early fracture systems controlling petroleum migration, and on other subtle trapping mechanisms. The concept of drape folding over basement faulting can be related to the concept of fault control of facies changes. Therefore, establishment of fault trends in the basement may aid in predicting stratigraphic traps. Using this approach, success in exploration may be improved by developing exploration models which incorporate basement level tectonics with stratigraphic and seismic anomalies occurring at shallower depths. End_of_Article - Last_Page 550------------