--> --> Abstract: Recognition of Oligocene and Miocene Lowstand Channel Complexes in the Western Nile Delta, by Stiig B. Larsen, Alaa Atef, Gerhard J. Brink, Axel Kellner, and Luis S. Vergara; #90082 (2008)

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Recognition of Oligocene and Miocene Lowstand Channel Complexes in the Western Nile Delta

Stiig B. Larsen1, Alaa Atef2, Gerhard J. Brink1, Axel Kellner2, and Luis S. Vergara2
1Canyon Energy Ltd, Dubai, United Arab Emirates
2Exploration, RWE-Dea Egypt, Cairo, Egypt

Pre-Messinian Nile Delta depositional systems have, until recently, been subjected to limited hydrocarbon exploration. Oligocene and Miocene well data and outcrops are sparse. High quality 3D seismic data and a sequence stratigraphic approach improved understanding gross depositional systems and hydrocarbon trapping elements.

The study area covers approximately 15,000 square kilometers. Three wells penetrations of upper and middle Miocene sediments in the study area make it possible to define fundamental sequences. This seismic well iteration also aided in extending the interpretation to the deeper undrilled Lower Miocene and Oligocene sequences offshore. Type 1 unconformities, transgressive and maximum flooding surfaces provide a regional geological framework. Maximum flooding surfaces are however, typically of limited extent due to subsequent erosion.

Seismic delineation of lowstand complexes in combination with attribute extractions allow the identification of depositional elements such as channels, levees, splays and ponded deposits within incised valleys, erosional canyons and broad channel confines. Most of the channel systems identified are regionally continuous. The updip proximal systems in onshore Western Nile areas (mostly upper and lower delta plain, upper slope) extend down-dip to the offshore Mediterranean ocean areas (upper and lower slope throughout).

Examples are drawn from both onshore and offshore Late Oligocene channel complexes. Despite extensive structural deformation, sequence definition and interpreted depositional architecture is preserved. These interpretations are attended by depositonal facies models, which are ultimately necessary for hydrocarbon exploration. Gross depositional systems maps specific to these sequences, summarizes interpretation results. Subsequent wells have validated the interpretation and model used.

AAPG International Conference and Exhibition, Cape Town, South Africa 2008 © AAPG Search and Discovery