--> Abstract: Integrated Analysis of Western Nile Delta Petroleum Systems, Egypt, by Claudius Vandre, Bernhard Cramer, Peter Gerling, Axel Kellner, and Jutta Winsemann; #90066 (2007)
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Integrated Analysis of Western Nile Delta Petroleum Systems, Egypt

Claudius Vandre1,2, Bernhard Cramer3, Peter Gerling3, Axel Kellner4, and Jutta Winsemann1
1Institute of Geology, Leibniz University Hannover, Callinstrasse 30, D-30167 Hannover, Germany
2Hydro Oil and Energy, Research Centre Bergen, Sandsliveien 90, N-5020 Bergen, Norway
phone: ++47-94878471, e-mail: [email protected]
3BGR - Federal Institute for Geosciences and Natural Resources, Stilleweg 2, D-30655 Hannover, Germany
4RWE Dea Egypt, 16, Road 253, Degla Maadi, Cairo, Egypt

The Nile delta area is a proven gas and condensate-producing province with continuing exploration potential. Production to date has been in the basin from Neogene sandstones in water Previous HitdepthNext Hit up to 500 m. However, in comparison with other large Cenozoic delta systems the Nile delta is still in an early exploration stage and several aspects of the petroleum geology are still poorly documented. Good knowledge about the petroleum system is a prerequisite for reducing risk by drilling of deeper pre-Miocene prospects and within the deep and ultra deep water of the Nile delta. Results from 2D depositional modeling (SedPakTM), 1D/2D basin modeling (PetroMod®), detailed molecular and isotopic analysis of test gases and headspace gases, and geochemical analysis of condensates and drill cuttings were linked in an integrated approach to analyse the regional petroleum systems of the western Nile delta. Depositional modeling carried out along a 360 km NW-SE striking transect in the western Nile delta was used to approximate the Plio-Pleistocene basin evolution, paleobathymetries, and sediment distribution as initial input for the subsequent 2D basin modeling. Molecular and isotopic characteristics of test and headspace gases indicate variable gas mixtures of both microbial and thermogenic origin with an overall increasing trend in gas wetness with Previous HitdepthNext Hit. High Pr/Phy ratios (> 3) of condensates and gas isotope data point towards derivation from source rocks rich in terrestrial type III kerogen. Source rock screening of the drilled Neogene section supports the absence of significant source rocks for thermal hydrocarbon generation. Despite this fact, there is enough disseminated organic matter in the drilled sediments (average > 0.5 % TOC) to generate significant volumes of microbial gas. Based on well data from the eastern Nile delta and onshore Western Desert, we inferred the existence of mainly gas-prone source rocks within the Middle Jurassic, Lower and Upper Cretaceous, Oligocene, and Lower Miocene. However geochemical gas and condensate-source maturity estimations compared to modeled thermal maturation narrowed down the probability of effective source rocks within the Lower Cretaceous to Oligocene. Previous Hit2-DNext Hit basin modeling suggests that the onset of hydrocarbon generation and expulsion is governed by deposition of the thick Miocene to Pleistocene overburden. Petroleum Previous HitmigrationNext Hit would have occurred principally up-dip along normal faults and through unconsolidated sediments into reservoirs and/or to the sediment surface. Since the deposition of source and reservoir rocks, timing of petroleum generation, Previous HitmigrationTop, and trap formation seems to be not a problem, integrity of effective seals is probably the most critical factor of the Nile delta petroleum systems.

 

AAPG Search and Discover Article #90066©2007 AAPG Hedberg Conference, The Hague, The Netherlands