Integrated seismic and petrophysical characterization of the Kharita Formation in the SELKIT and SETHOS fields, Western Desert, Egypt

Abstract

The Kharita Formation represents one of the principal Lower Cretaceous clastic reservoirs in the Shushan Basin, Western Desert, Egypt. This study integrates seismic interpretation and petrophysical analysis to evaluate the reservoir characteristics, structural controls, and hydrocarbon potential of the Kharita Formation in the SELKIT and SETHOS fields, South Umbaraka Area. The investigation was based on the interpretation of thirty 2D seismic profiles and conventional well-log data from the SELK-6, SELK-7, and SETHOS-16 wells. Seismic interpretation was conducted to delineate the structural framework, fault architecture, and trapping configurations, while petrophysical analysis was performed to determine lithology, shale volume, porosity, fluid saturation, and net-pay distribution. Neutron-density crossplots were also utilized to identify lithological variations and potential gas-bearing intervals. The seismic interpretation reveals that the study area is structurally controlled by a series of major normal faults and fault-bounded anticlinal closures that significantly influence reservoir distribution and hydrocarbon accumulation. Time- and depth-structure maps of the Kharita Formation indicate that both the SELKIT and SETHOS fields occupy structurally elevated four-way dip closures, providing favorable trapping conditions. Correlation of the Cretaceous succession further demonstrates the influence of fault-controlled compartmentalization and differential subsidence on reservoir geometry and thickness distribution. Petrophysical analysis indicates that the Kharita Formation consists predominantly of sandstone reservoirs with variable shale content and favorable reservoir properties. Seven hydrocarbon-bearing zones were identified, with net-pay thicknesses ranging from 11 to 63 ft. Shale volume values vary between 4 and 20%, total porosity ranges from 8 to 18%, and effective porosity ranges from 6 to 17%. Water saturation values range from 20 to 45%, corresponding to hydrocarbon saturation values of 55% to 80%. The most prospective reservoir intervals occur in Zone D of SELK-6 and Zone F of SETHOS-16, which exhibit favorable combinations of net-pay thickness, porosity, and hydrocarbon saturation. The integrated results demonstrate that hydrocarbon accumulation within the Kharita Formation is controlled by the combined influence of depositional architecture, reservoir quality, and fault-related structural trapping. This study highlights the value of integrating seismic and petrophysical datasets for reducing exploration uncertainty and improving reservoir characterization in the Shushan Basin and analogous Lower Cretaceous reservoirs of the Western Desert.