Stratigraphic Discrimination between Kafr El-Sheikh and El-Wastani Formations in the Offshore Eastern Nile Delta, Egypt: An Integrated Geological Approach

An integrated geological approach of biostratigraphy, paleoenvironmental analysis, seismic facies, and pore pressure data was employed to discriminate between the Kafr El-Sheikh and El-Wastani formations in the offshore eastern Nile Delta area. The foraminiferal biostratigraphic analysis of Pliocene-lower Pleistocene successions in Andaleeb-1, Temsah NW-10, Temsah NW-11, and Barboni NW-1 wells revealed that the Kafr El-Sheikh Formation is of Early Pliocene (Zanclean) age. The formation consists of pressurized shale with high to moderate brightness seismic reflectivity, gently dipping toward the north at the shoreline area and nearly horizontal reflectors northward. Locally, bright reflectors configured as channel-fan and frontal splay geometries signal episodes of turbiditic sedimentation. The formation yields foraminiferal assemblages relevant to an outer shelf-upper slope paleoenvironment; though seismic data from the Andaleeb-1 area imply deeper, basinal deposition, likely due to downslope transport of the shallower fauna by turbidity current to the basin. The overlying El-Wastani Formation shows high brightness, large foresets seismic reflectors, with extensive upper sand bodies and overpressured basal shale, and contains diverse benthic fauna typical of deltaic shelf settings. ... mehrThe Kafr El-Sheikh/El-Wastani formational contact south of the shoreline area shows a subaerial unconformity marked by a seismic toplap, while in the deep marine, the boundary is marked by a downlapping surface, coinciding with a remarkable shift in biofacies. Pore pressure profiles further support the boundary placement in offshore areas, showing a pressure drop across the contact. Accurate placement of this formational boundary improves stratigraphic resolution and supports safer, more effective drilling and casing strategies.