Petroleum System of the Central Western Desert, Egypt: Field Discovery and Development of the Cretaceous Reservoirs

Tom M. Maher, Daniel E. Helgeson, Ron E. Roberts, Alan P. Clare, Peter Munday, and Martin J. Oldani
Apache Egypt Companies, Cairo, Egypt

Exploratory drilling in the 1960-70's in the central Western Desert, Egypt, discovered many oil fields, and also deemed large areas non-prospective due to a number of non-hydrocarbon bearing wells. This phase of drilling was based mainly on regional 2d seismic data. Since 2000, acquisition of numerous high quality 3d seismic surveys around these older wells has shown that many of the non-productive wells were simply placed outside of structural closure. Drilling targets based on the modern 3d seismic data have a high success rate (>80%), albeit with relatively small field sizes that range from 1-10 Mboe. The East Bahariya, El Diyur, and North El Diyur Concessions have several such fields that will be highlighted to show the extent and nature of the petroleum system in the Upper Cretaceous of this area. Over 120 exploration and development wells have been drilled during the last five years in 25 separate oil accumulations, and the three concessions are currently producing 20,000 bopd. The Abu Roash and Bahariya fluvial/deltaic sands are the principal reservoir objectives. Multiple phases of extensional and compressional tectonic events formed the traps that accumulated the oils that migrated into this area over long distances from the mature basin center, greater than 20+ kms away. Column heights and areal extent of the fields are limited by a lack of good seals, giving rise to multiple opportunities for cross fault leak points. The oils produced are derived from Jurassic terrestrial shales and coals and have variable physical properties.

AAPG Search and Discovery Article #90072 © 2007 AAPG and AAPG European Region Conference, Athens, Greece