Improving Reservoir Characterization Using a Qualitative Analysis From Seismic Data. Orinoco Heavy Oil Belt, Venezuela

The results of a structural and stratigraphic interpretation using seismic data of the area between Morichal and Cerro Negro Fields in The Orinoco Heavy Oil Belt in Venezuela are discussed. The seismic reflections at the top of the target interval (The Terciary Morichal Member of the Oficina Formation), have good continuity and reflection character, however, the challenge is to understand the reflection character at the center and in the bottom of the massive sands that comprise this reservoir, where the acoustic impedance contrast becomes poorer in a paleo-environments that suggest a high-energy of sedimentation. The methodology involves definition of regional markers integrating cores well logs and seismic data. To achieve the objective of the study, it has been fundamental the extraction of stratal slices from volumes derived from multi-attribute analysis and facies classification within target interval. These representative stratal slices and facies results for each unit have been correlated with sedimentological analysis, net sand maps and available production tests, constraining stochastic simulations (SIS) of properties for calculations of OOIP volumes for the area. Finally, feasibility study for seismic inversion performed in this study demonstrated that elastic parameters are the best choice to perform a quantitative seismic characterization for the area.