Integrated Multidisciplinary Approach to the Middle Miocene, Serravallian Reservoir Study: A Case Study from Akhen Field, Nile Delta, Egypt

Essam Sharaf², Osama Abdel-Aal¹, and Kareem El-Hadidi^1
1Geology, Mansoura University, Mansoura, Egypt
²BP, Cairo, Egypt

Serravallian turbidite channel reservoirs are difficult to develop efficiently. The depositional mechanism of these channels creates sand bodies whose thickness and quality can vary rapidly over a short distances.

The lithologic and stratigraphic architecture of these channels are constructed from the cored intervals, paleontologic content of the reservoir intervals and geochemistry of gas isotopic composition of the reservoir. The core data indicates that these complex channels consist of several vertically stacked channels that may be migrated laterally.

The turbidite deposits at Akhen reflect varied depositional fabrics from poorly to moderately sorted and non-graded to graded. Well logs and core data suggest at least 3 sand packages in a cyclic pattern. Each package displays incomplete fining upward cycle with variable petrophysical properties.

Lateral correlation of the sand units is crucial for reservoir size, reserve calculation and future well planning. Perforating pressure data obtained from one well drilled into the reservoir revealed slight depletion in the upper zones, and with two years separating the wells, confirmed a degree of lateral communication. Currently, a pressure gradient continues to exist between the wells due to permeability effects and lateral distance. Although the seismic resolution is not good enough to map the turbidite channels clearly, one channel was mapped at the western side of the reservoir. The RMS amplitude of this channel shows moderate sinuosity that probably reflects lateral channel migration.

Integrating sedimentology, biostratigraphy, well logs and seismic data allowed constructing depositional model of the Serravallian reservoir and predict the reservoir heterogeneity for deeper exploration targets in Akhen area.

AAPG Search and Discovery Article #90078©2008 AAPG Annual Convention, San Antonio, Texas