Integrated Study of Bentiu and Aradeiba Reservoir Formations, Hamra East Oil Field—Muglad Rift Basin, Sudan

Abstract

The Muglad Rift Basin represents the largest of Sudan’s interior basins with NW-SE orientation and up to 13 km of Cretaceous-Tertiary continental sediments. Bentiu and Aradeiba are the main reservoirs. This study deals with integrated multi-scale analysis using six sedimentological methods (conventional cores analysis and thin section description, well log interpretation, SEM, XRD, and two seismic sections). Nine siliciclastic lithofacies represent fluvial, deltaic and lacustrine depositional environments. On the field-scale, the formations reveal a variation in sandstone bodies, geometry, thickness, and architecture. On the macro scale, the reservoir quality varies laterally and vertically, controlled by depositional environments and a general fining upward trend with different degrees of connectivity. On a micro-scale, the reservoir quality is affected by diagenetic processes. Kaolinite is dominant as pore fill and coat. Average porosity and permeability in Bentiu are 23.8% and 369 mD, and 20.5% and 35.1 mD in Aradeiba.