3D Modeling and Visualization Applied to the Characterization of Brazilian Sandstone Reservoirs

Marco A. S. Moraes, Yeda Backheuser, and Rosane T. Faria

Displaying reservoir properties in three dimensions greatly enhances the integration of data derived from cores, well-logs and seismic, leading to a more effective approach to solve reservoir characterization problems. Three- dimensional visualization represents a powerful means for interdisciplinary reservoir evaluation, serving as a common base for engineers and geoscientists to enhance the understanding of reservoir property distribution.

Examples from several Brazilian reservoirs, both onshore and offshore, are used herein to show the approaches and new insights obtained by different projects. In densely drilled fields, flow units have been inferred based on core vs. log property correlation, using multivariate analysis techniques, and then mapped based on log-data interpolation and, in some cases, stochastic modeling. In other situations, mostly from offshore areas, where well to well distances are several hundred meters or more, log interpolation is applied to the recognition of general trends, giving very limited information on lateral variability. In these conditions, seismic-driven geostatistics is essential for better reservoir quality delineation. The great increase in the use of horizontal wells introduces new challenges to 3D modelers, not only in terms of the information obtained in the existing wells but also as different alternatives for new wells are tested before drilling.

The application of 3D modeling technology is introducing several beneficial aspects for the understanding of Brazilian reservoirs. Features including complex sand-body geometry and barrier distribution are much better defined, and hence effectively incorporated into flow simulation models.

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California