Quantification of reservoir rock properties (Porosity, Permeability and Vshale) in the reservoir rock units of South Lake Albert Basin, Albertine Rift, Western Uganda

The South Lake Albert Basin (SLAB) is part of the Albertine graben, the northernmost part of the western arm of the East African Rift System (EARS). The study focused on interpretation of three-dimension (3D) seismic and suites of wireline log datasets, construction of 3D models, facies analysis, surface geological mapping and integrating both subsurface and surface data to assess reservoir rock properties. From previous studies, low to moderate reservoir quality (porosity, permeability and Vshale) was realized, and most of the drilled wells encountered two or more separate stacked oil accumulations (complex reservoirs) whose lateral extent had not been well understood and that was attributed to poor reservoir property distribution. The major aim of this study is to quantify the reservoir rock properties and integrating both subsurface and surface data in order to evaluate the reservoir property distribution within the study area, with specific objectives of (1) interpreting subsurface and facies modelling data and (2) to conduct field (surface) data sampling, analysis and interpretation (3) integrating both subsurface and surface data. From the obtained results, it was deduced that the lithology from facies modelling (subsurface results) and field geological mapping (surface results) data and the reservoir rock properties in both Kaiso Tonya and Kingfisher areas generally had moderate to good values for all the interpreted reservoir rock properties that were quantified however, the section under Lake Albert had better results. In addition, the reservoir rock properties for both subsurface and surface data were changing at very short intervals with intercalations of clay, silt, fine and coarse sands that was attributed to short changes in climatic (wet and dry) conditions that happened over time during the sedimentation process. It was further deduced that sediment compartmentalization and intercalation have effect on the reservoir rock properties.