Static reservoir modeling using stochastic method: a case study of the cretaceous sequence of Gamtoos Basin, Offshore, South Africa

Abstract Gamtoos Basin is an echelon sub-basin under the Outeniqua offshore of South Africa. It a complex rift-type basin with both onshore and components consists relatively simple half-grabens bounded by major fault to northeast. This study mainly focused on evaluation reservoir heterogeneity Valanginian depositional sequence. The prime objective this work generate 3D static model for better understanding spatial distribution discrete continuous properties (porosity, permeability, water saturation). methodology adopted in includes integration 2D seismic well-log data. These data were used construct models lithofacies, porosity, saturation through petrophysical analysis, upscaling, Sequential Indicator Simulation, Gaussian Simulation algorithms, respectively. Results indicated that modeling adequately captured geometry distribution. In study, geocellular delineates lithology into three facies: sandstone, silt, shale. Petrophysical integrated facies within identify best location has potential produce hydrocarbon. statistical analysis revealed sandstone ranges between 8 22%, 0.1 mD (< 1.0 mD) mD, 30–55%. Geocellular results showed northwestern part properties, followed central Basin. Findings from have provided information needed further gas exploration, appraisal, development programs