Quantitative Characterization of Modern Carbonate Platforms to Improve Geologic Modeling

A fundamental understanding of carbonate systems is integral to developing realistic geologic models and reservoir simulations, which inevitably impact the assessment of field volumetrics, flow properties, reservoir producibility, and even field development strategies. The ability to predict and model facies distributions in ancient carbonate rocks is essential for accurate evaluation of reservoir-scale heterogeneity and identification of exploration-scale play fairways. However, carbonate systems are inherently complex and thus challenging to accurately describe and model, particularly when working with poor quality seismic or limited well data. To address this issue, we focus on isolated carbonate platforms to understand and numerically characterize geobody distribution and variability in modern carbonate systems. Specifically, we spatially and quantitatively characterized seven modern carbonate platforms using ExxonMobil research datasets and high resolution facies maps from the National Coral Reef Institute. The platforms analyzed include: Bu Tinah shoal, Arabian Gulf; Glovers Reef, Belize; Heron Island, Great Barrier Reef; Little Bahama Bank, Caribbean; Rasdu atoll (Maldives), Indian Ocean; Taka Lambaena, SE Asia; and Vieques Island, Puerto Rico. These modern analogs represent a wide range of carbonate environments differing in size, energy regime, climate, depositional motif, sediment fill, tectonic history, and accommodation style. Geobody variability and distribution on a platform and sub-platform scale established governing numerical relationships that will be used to constrain modeling inputs and create realistic training images which will ultimately improve 3-dimensional models of ancient carbonate systems. The results of this study have been compiled into a modern carbonate platforms database that contains (1) data on facies proportions for discrete facies modeling (probability distributions and variograms generated at the sub-platform scale by facies type and energy regime) across a genetically varied modern platform dataset; (2) guidelines to assist with modern analog selection and model simulations; (3) workflows for analyzing new platforms; (4) relevant maps and imagery; and (5) other linked references to provide supplementary and analogous data for guiding geobody population in training images and geologic models.

AAPG Search and Discovery Article #90142 © 2012 AAPG Annual Convention and Exhibition, April 22-25, 2012, Long Beach, California