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Figure 8. (a) Cross-section showing water-bearing zones in upper part of Bentiu reservoir, due to lateral seal failure, and pay zone in lower part (Bentiu III sand). Bentiu III sand is juxtaposed against Aradeiba Shale resulting in good lateral seal. Top seal is provided by intra-Bentiu shale. (b) Cross-section with dry hole, where there is lack of lateral seal for Bentiu reservoir. These two cross-sections illustrate lateral-seal risk associated with footwall closures. Optimum fault throw in comparison with Aradeiba Shale section is critical for trap integrity.