Abstract: 3-D Geocellular Modeling of Fluvial-Lacustrine-Deltaic Sequences of the Potrerillos Formation (Upper Triassic) in the Barrancas Oil Field, Cuyo Basin, Argentina

JALFIN, GUILLERMO A, GUILLERMO FRATI, JOSEPH YEH, BEG, MARINA A. ABASTO, GUIDO COCUCCI, AGUSTIN DIZ, and PABLO AGRAZ

The Barrancas Oil Field is highly compartmentalized, primarily because of normal faults that divided the area into independent blocks. Furthermore, the discontinuous nature and reduced size of the fluvial-lacustrine-deltaic reservoirs display a complex architecture controlled by changes in the accommodation space. Nevertheless, an accurate 3-D facies model was generated using a complete data set that includes 80 well logs, cores, a 3-D seismic cube, and outcrop information. The geocellular modeling is accomplished in four steps: determining petrophysical attributes for each well, creating surface grids for each geologically distinct correlatable unit, interpolating petrophysical attributes between wells and performing geocellular operations and calculating original oil in place (OOIP). The computer model contains 10 genetic units and a total of 6.2 million cells where 4 million of these are active with an average porosity and water saturation of 19% and 55%, respectively. Geological cellular layering character also controls intragenetic unit heterogeneity by modeling the relative stacking of cells within each genetic unit that include: cell dimensions, proportional layering, onlap and truncation. The genetic unit surfaces control intergenetic unit heterogeneity and constrain petrophysical attribute interpolation vertically and laterally within the flow unit.

AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria