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Figure 4. Schematic illustration of lateral seal dependence on the Aradeiba thickness, lithology, and the amount of fault throw. (a) Footwall block; fault throw is less than the thickness of Aradeiba Shale, massive Aradeiba Shale provides the top and lateral seal for Bentiu reservoir. Oil column increases with increasing fault throw. Where fault throw is larger than the thickness of Aradeiba Shale, Bentiu objective is juxtaposed against Zarqa sand, resulting in lateral seal failure. (b) Hanging wall fault block; Aradeiba intraformational shale and fault smear provide the top and lateral seal for Aradeiba reservoirs; for Bentiu Sand, the objective is juxtaposed against the Bentiu massive sand across fault causing lateral seal failure. However, fault smear can provide weak lateral seal to form a limited oil column.