Satellite Images of Shallow Water Carbonate Depositional Settings - Examples of Exploration- and Development-Scale Geologic Facies Variation

Paul M. Harris, William S. Kowalik, Brad P. Dean, Anthony J. Lomando

Information from modern shallow water carbonate settings is commonly incorporated into analysis of reservoir-scale heterogeneity problems and exploration-scale plays. The modern analogs provide a means to illustrate the distribution of porous carbonate facies within the overall setting. Often these analogs become an important part of the geologic model as they show the scale, trend, and interrelationships of facies that might be related to reservoir and non-reservoir rock distribution.

We acquired and processed 30 Landsat and SPOT satellite images from 9 "classic" carbonate areas that should help fulfill the needs of most exploration and development geologists for analogs. The images include a variety of depositional settings and are important because they show contrasting ways in which the different settings may be related.

-- The Bahamas, Caicos Platform, Chinchorro Bank, and portions of Belize, for example, are isolated carbonate platforms, whereas the other areas are attached shelves.

-- The Abu Dhabi and northern Yucatan areas are often cited as modern examples of ramp-style shelf-to-basin transitions.

-- South Florida, portions of the Belize area, and the Great Barrier Reef of Australia are superb examples of a rimmed shelf margin.

-- A broad, deep lagoon is especially well expressed in the Great Barrier Reef and Belize shelf examples.

-- South Florida, Belize, the Great Barrier Reef, Shark Bay and Abu Dhabi contain areas of mixed carbonate and siliciclastic deposition.

-- Variability of reef continuity and distribution is shown in South Florida, the Bahamas, Caicos, Belize, the Great Barrier Reef, and Chinchorro Bank.

-- Carbonate sand bodies assume variable morphologies in the Bahamas, Caicos Platform, Yucatan, and Abu Dhabi areas.

The images illustrate the geologic framework in modern carbonate environments and thereby graphically depict the geologic characteristics that can be expected in ancient carbonate settings. The geologic framework is important at the development scale where lateral variation of porosity and permeability, i.e. reservoir quality, are commonly tied to facies changes, and facies dimensions are required as input to reservoir models. The geologic framework is essential at the exploration scale for reservoir facies prediction and stratigraphic play concepts which are related directly to depositional facies patterns.

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