Evaluation of Hydrocarbon Potentiality of the Lower Safa Reservoir, Pepi Field, Shushan Basin, North Western Desert, Egypt

Document Type : Research and Reference

Authors

1 Geology Department, Faculty of Science, Tanta University, 31527 Tanta, Egypt

2 Khalda Petroleum Company, New Maadi, P.O Box 560, Maadi, Cairo, Egypt

Abstract

The Middle Jurassic Lower Safa Member serves as a hydrocarbon reservoir in Shushan Basin, North Western Desert, Egypt. The present work deals with studying the subsurface setting and reservoir properties of this member to assess its hydrocarbon potentiality in the Pepi field.  Seismic interpretation of thirty 2D seismic sections was used to determine the geometry and the detailed structural properties affecting this member. Well-log data available from five well-logs (Pepi-1X, Pepi-2, Pepi-5, Pepi-6, and Pepi-8) was utilized to determine the various reservoir parameters distinguishing the pay zone to highlight the promising locations for further exploration and development. Interpretation of the seismic data showed two master faults (F1 and F2) forming a half-graben block that trends NW-SE and NE-SW, respectively. These faults reflect the structural control of hydrocarbon accumulation in the Pepi field. Results of neutron-density cross-plots showed that the lithology of the studied Lower Safa reservoir is mainly sandstone with some calcareous cement. Vertical demonstration of the petrophysical data via Litho- Saturation cross-plots and lateral layout through the iso-parametric maps helped identifying the lateral variation of petrophysical parameters, reservoir thickness and to define the most suitable place for locating new productive wells. The estimated petrophysical parameters of the reservoir throughout the study area ranges from about 7.6 % to 11.3 % for effective porosity, from 1.8 % to 8.3 % for shale volume and from 47.3 % to 85.1 % for hydrocarbon saturation.  These results revealed that good reservoir parameters distinguish the Pepi field. Analysis of the reservoir pressure was utilized to define the reservoir fluid type and degree of connectivity of hydrocarbon in sand-bearing parts. Integrating obtained results indicates that the Lower Safa Member of Pepi field contains commercial hydrocarbon accumulation with a good chance to increase 

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