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Advances in Seismic Stratigraphy of Carbonate Platforms and the Importance of Integrated Interpretation Using Time- / Depth-slice and Well Calibration Data

Abstract

Advances in seismic and sequence stratigraphy of carbonate platforms have been led by a series of step changes in understanding based on seismic recognition of geometries, classification of geometries, calibration of seismic geometries with outcrop data, and the development of 3D seismic data (seismic geomorphology). Seismic stratigraphy has provided practitioners with a geometric framework to understand the distribution of carbonate facies and diagenetic products. This has allowed an evolution in conceptual thought from a “carbonate facies mosaic” to a more predictive chronostratigraphic framework that can be used to populate facies and rock properties in the subsurface. 3D seismic data from several regions show the utility of using time- and depth-slice (plan view) interpretations in concert with cross-section views. Recognition of features in plan view allows direct correlation of seismic features with depositional concepts (seismic geomorphology). Some features such as clinoforms or patchreefs can be mapped in plan view, but may not be consistently mapped in seismic cross section due to resolution or imaging constraints. Mapping of steep-sided carbonate slopes (shelves or isolated platforms) can be aided by plan view interpretation to recognize major failure surfaces, lobate geometries, and channelized deposits. Karst features can be mapped and correlated to well productivity. The overall evolution and growth of carbonate platforms can also be viewed in plan view. When viewed as successive “shallower” images, the growth can be illustrated through geologic time. Interpretation of some of these features may require significant manual picking (due to poor reflector quality). Calibration of seismic geometries with seismically-tied well data (including image logs and core) allows the interpretation of the geologic and reservoir significance of seismic geometries. The geometries and resulting seismic facies can then be used to populate reservoir properties between wells and especially in areas of sparse well data.