Development of the Geological Classification System Preliminary Grouping of Reservoirs - Classification meetings with Geologic Experts - strict geologic groupings of reservoirs utilizing geologic principles and statistical criteria Final Classification System - Decided to use geological considerations exclusively -Validated methodology for describing reservoirs in terms of lithology, deposition, diagenesis and structural overprint - Balanced the issues of -Meaningfulness: distinct level & types of heterogeneities - Manageability: few enough groupings to serve as classes for the Oil Research Program - Result: 22 Geologic Classes (16 Clastic; 6 Carbonate)