Fault seal behavior in existing fields provides analogs for prospects and plays. They provide analogs for trap types, new fault dependent traps, seal behavior, column heights, percent fill, vertical hydrocarbon distribution within a series of stacked sands, and lateral hydrocarbon distribution within a single, compartmentalized reservoir.
Analogs provide a way of assessing a prospect when our cleverness fails. We may not understand exactly how displacement affects hydrocarbon column heights but an empirical plot of fault throw versus oil column height gives us some important assessment information. Similarly, documenting the effect of faults in controlling migration pathways into one field aids in risking an adjacent prospect.