Sedimentological analysis and reservoir characterization of an estuarine bar: An example from the El-Basant Gas field, Nile Delta, Egypt

Abstract

Estuarine tidal bar reservoirs are challenging due to their complex architecture and limited examples. This study represents an integrated sedimentological analysis and reservoir characterization for estuarine bars using an example from El-Basant Gas Field (East Nile Delta). In this study, the sedimentological analysis and neural network techniques are employed to characterize hydraulic flow units of an estuarine bar reservoir using core, borehole image, and log data. The available integrated core and borehole image data help to subdivide the estuarine bar into six sedimentary facies types and are grouped into four facies associations: proximal tidal bar, distal tidal bar, estuarine mud, and tidal channel. The estuarine bar reservoir is subdivided into three main flow units based on the sedimentary fabric. Flow unit 1 characterizes the mud-free sandstones of proximal tidal bar and tidal channel associations. Flow units 2 and 3 characterize the mud-rich sandstones of the distal tidal bar and the upper part of the tidal channel. The diagenetic impact appeared in the reduced quality of the tidal bar deposits due to patch cementation and mud-filled, small-scale fractures and faults.