Seismic Resolution Unit. A Measure for Reservoir Description

A methodology for reservoir seismic interpretation is presented and a new concept of seismic attribute mapping is introduced which seeks for the definition of a reference seismic resolution measure to be used with the further seismic dependent reservoir tasks: the seismic resolution unit - SRU. The utility of a differential reservoir mapping unit from those used on the exploration phase, arises from the geology and engineering development need of having an enhanced image of reservoir structures and their physical properties, associating this image to a measurement that indicates both how the internal discontinuities, local petrophysical variations and differential lithofacies are defined, and how are their relationships with feasible fluid flow simulation units. One xample of a SRU based on 3D seismic impedance (e.g., a volume-based impedance) is presented, based on a interpretative ternary ystem which establishes a bulk litho-physical unit, considering lithological and petrophysical factors. This unit is considered as a reference, in seismic analysis scale, to a subdivision for a certain reservoir. These concepts are being applied in an offshore Brazilian field - for tertiary turbidites reservoirs - to guide further modeling, inversion, geostatistical and mapping works at the description phase that will support its development based on horizontal wells.