Quantifying the Influence of Hard Seals on Pore Pressure in Egypt Nile Delta Offshore Region

Conventional disequilibrium compaction models have been robust in estimating pore pressure in the Nile Delta offshore area with dozens of wells being delivered safely and effectively. However, exploration success in deeper intervals below the Messinian evaporitic seal has come with the challenge of applying well-understood pressure prediction models in the Pre-Messinian overburden. Large errors in pore pressure estimation have been observed resulting in underbalanced conditions and, in some cases, well control events with considerable NPT. Overpressure generating mechanism in the post-Messinian is disequilibrium compaction. Hard sealing properties of the evaporitic layer contributes in elevating pressure beneath the Messinian beyond compaction origin -- caused by secondary pressure generation. Our methodology used both 2D and 3D basin models to simulate pressure genesis from burial, thermal expansion and fluid flow, as well as the complex interaction with the Messinian evaporite seal. This new approach has improved our understanding of pressure distribution below the Messinian seal leading to more accurate pre-drill predictions. Planning for the appropriate mud weights below the Messinian has contributed to safer, as well as best in class, drilling performance in the Nile Delta.