Reservoir characterization and 3D modeling of the Aptian Alamein Formation in North Razzak area (North Western Desert, Egypt)

Abstract

Improving exploration and development techniques of fossil fuels are essential for continuous reserves development. Although there are many oil discoveries in the Razzak Area (North Western Desert, Egypt), there are also many dry wells. Therefore, the tectonic setting and reservoirs characterization of the study area has to be fully understood. Twenty 2D highly filtered stack zero-phase seismic sections and logging data of four wells were analyzed. According to seismic sections and structure contour maps (both time and depth), there is one major structural high (horst). It is a part of the regional Jurassic rift system. The NE Jurassic rifts continued during the deposition of the Early Cretaceous strata as growth faults and have been rejuvenated or continued during the closure of the Neotethys Ocean. During the Late Cretaceous, the compressional stress resulting from the collision between African and Eurasian plates has led to the inversion of the Razzak basin, where some segments of the main faults are transformed from normal to reverse and the hanging walls formed plunging drag fold, which was dissected by a set of NW-SE normal faults. Four prospective closures in the Razzak Field were highlighted. Based on integrated petrophysical tools (Gamma Ray, Sonic Log, Resistivity Deep, Neutron Porosity, and Bulk Density) in four wells (NRZK-1, NRZK2, NRZK-3, and NRZK-4), the Aptian Alamein Formation (mainly dolomite) was interpreted to be a good reservoir and can be subdivided into two zones (Upper Alamein and Lower Alamein) with different reservoir quality. In addition, 3D structure, facies, and petrophysical models were built based on integrated geological and petrophysical data. The results indicated that integrating both seismic profiles with logging data, even from a small number of wells, is highly valuable in evaluating reservoir quality and defining future prospective.