A Source-to-Sink and Reservoir Quality Prediction Workflow: The Offshore Nile Delta

Abstract

We outline a novel workflow for utilising hinterland datasets to predict reservoir quality and distribution in frontier exploration regions and apply this methodology to a case study in the Nile Delta. Geochemical data is intersected with drainage areas to derive first-order bulk chemical compositions. Drainage polygons are modified using thermochronological data and paleocurrent information to create paleo-drainage areas. Volume of denuded sediment is then estimated from uplift data and integrated with stratigraphies to verify the link between hinterland and offshore geology. Finally, chemical data are used to predict the modal composition of sediment within key reservoir and seal horizons.

The workflow presented utilises datasets otherwise overlooked in the exploration process and reduces the reliance on more speculative inputs such as paleogeographic reconstructions and paleoclimate modelling. The workflow provides quantitative predictions with percentage certainties, allowing explorers to understand the degree to which results can be relied upon.

To demonstrate this workflow we look at the offshore Nile Delta sediments in the Eastern Mediterranean. The Nile’s vast hinterland is comprised of sediments derived from the Congo Craton and Saharan Metacraton, Cenozoic Flood Basalts and Phanerozoic sediments from the Ethiopian Highlands, and Phanerozoic sediments and Cenozoic carbonates from the Egyptian Red Sea Hills. Recent detrital studies on the offshore Nile Delta have shown the provenance of the Oligocene-to-Pleistocene sediments remained the same since the Rupelian, 31 Ma (Fielding et al., 2017). Fluctuations in the amount of mafic material recorded in the delta during the Oligocene and Pliocene versus the Miocene and Pleistocene have implications for discontinuous reservoir quality in the basin. Using the workflow outlined above and incorporating additional datasets and methods, we aim to quantify this variation in mafic sediments and its implications for predicting reservoir quality in the offshore Nile delta.

Fielding, L., Najman, Y., Millar, I., Butterworth, P., Garzanti, E., Vezzoli, G., Barfod, D. and Kneller, B., 2018. The initiation and evolution of the River Nile. Earth and Planetary Science Letters, 489, pp.166-178.

AAPG Datapages/Search and Discovery Article #90350 © 2019 AAPG Annual Convention and Exhibition, San Antonio, Texas, May 19-22, 2019