Bureau of Economic Geology, The University of Texas at Austin (www.beg.utexas.edu).
AAPG Annual Convention, Calgary, Alberta, Canada, June 19–22, 2005
Multidisciplinary Reservoir Characterization of a Giant Permian Carbonate Platform Reservoir: Insights for Recovering Remaining Oil in a Mature U.S. Basin
Despite more than 60 years of production history, recovery of the 1.5 Billion barrels of oil in Fullerton field, a shallow water platform carbonate reservoir of Early Permian age in the Permian Basin of West Texas, has proven difficult. To develop a better understanding of the distribution of the original hydrocarbon resource and to devise strategies to recover the huge volume that still remains, we undertook a comprehensive, multidisciplinary study of the reservoir. Crucial elements of the study include (1) geological models of analogous outcrops, (2) description of more than 14,000 feet of core, (3) new core data for rock fabric analysis, (4) analysis and correlation of more than 850 wireline log suites, (5) a 3-D seismic inversion porosity model, (6) a 35,000 acre (12,000 hectare) reservoir model, and (7) a 2,000 acre (750 hectare) flow simulation.
Important results of the study include the following. The study demonstrates clearly the necessity of robust outcrop models for proper interpretation of geological, petrophysical, and geophysical subsurface data sets. It also illustrates the fundamental value of a geologically-constrained reservoir framework in realistic reservoir modeling and simulation. It shows the tremendous potential of iterative 3-D seismic porosity inversion models in defining porosity distribution. It reveals the importance of a rock fabric based approach for defining porosity/permeability relationships. Finally, the study offers critical guides to the distribution of original and remaining oil volumes and insights to how these resources may best be recovered.