APPLICATION OF DEEPWATER OUTCROP ANALOG DATA TO 3-D RESERVOIR MODELING

The situation presented at the Diana field in the ultra deepwater Gulf of Mexico is a common one: a hydrocarbon reservoir expressed by a single-cycle seismic event and by three appraisal wells spaced thousands of feet apart. There is, however, excellent core coverage which enables close calibration of seismic and well data. Integration of seismic, well log and core data suggests a relatively channelized reservoir in an up dip position becoming more sheet-like and layered down dip. This subsurface data did not have the resolution to provide the dimensional and architectural data required to condition an object-based 3-D geologic model needed for more accurate flow simulation and well-performance prediction. To solve these uncertainties, deepwater outcrop analog data from the Lower Permian Skoorsteenberg Formation, South Africa and the Upper Carboniferous Ross Formation, western Ireland were integrated with the seismic and well data from the Diana field. Bed scale reservoir architectures were quantified with photo-mosaics and by correlation of closely spaced measured sections. Bed continuity, connectivity and vertical and lateral facies variability data were also collected as these factors ultimately control the reservoir behavior. From these measurements a spectrum of channel dimensions and shapes were compiled to condition the modeled objects. These data were compared to Diana specific seismic and well data and adjusted accordingly. The advantage of the resulting geologic model is that it incorporates geologic interpretation, honors all available data and models the reservoir as discrete objects with specific dimensions, facies juxtaposition and connectivity. This effort provided the framework for optimal placement of wells to maximize the architectural and facies controls on reservoir performance.