Downslope Internal Evolution of a Deep Water Slope Channel Complex: Giza Field, West Nile Delta

Butterworth, Peter; Vergaehe, Jona
Exploration, BP, Cairo, Egypt.

The West Nile Delta has a number of Pliocene-aged channel complex, (channelised) sheet and channel-levee reservoir systems deposited post the Messinian salinity crisis and the re-establishment of a muddy depositional slope on the Nile Delta cone. Gas discoveries in all these different turbidite channelised architectural elements (Ruby, Fayoum, Giza Fields) in the offshore Nile Delta are amplitude anomaly driven, and are dispersed around the modern day Rosetta Canyon in water depths ranging from 300m to 900m.

Structurally, the West Nile Delta is characterised by steep, fault-bounded margins which exerted a fundamental control on the deposition of slope canyon and channel systems in the Pliocene play fairway. The Giza Field comprises a middle Pliocene slope channel complex, and forms an integral part of the Phase I BP West Nile Delta development project.

Visualisation of the internal geometry of the Giza channel complex is based on 3D multi-azimuth (MAZ) seismic data aligned to complete conventional core data recovered from both the exploration discovery well and a subsequent appraisal well. The combination of high resolution seismic tied to the core scale observations provides spectacular insights into the gross seismic architecture, internal geometry, stacking patterns and downslope evolution of the internal fill of the Giza Field slope turbidite channel complex.

This paper will demonstrate the facies shift and channel geometry variation with the Giza channel reservoir fairway, from incision and bypass to the initial backfill within a low sinuosity aggradational stacked channel phase, to a more sinuous constructional channel levee fill style and ultimate channel abandonment. Understanding the internal fill based on the MAZ seimsic tied to the extensive conventional core data is key to understanding connectivity, net:gross distribution, perched water and aquifer modeling.

AAPG Search and Discovery Article #90155©2012 AAPG International Conference & Exhibition, Singapore, 16-19 September 2012