Application of 3D static modeling for optimal reservoir characterization

Abstract

Robi-1 field, located in the Central Swamp-I depositional belt of the Niger Delta, is largely typified by uncertainties due to complexity of reservoirs features, which resulted in difficulty in imaging and capturing all structural possibilities. These in turn affect the effectiveness of further exploration, appraisal, and development. This study was, therefore, undertaken to produce 3D structural and property models to better characterize, image and capture the reservoirs by integrating 3D seismic, logs and petrophysical parameters from the Robi-1 well. Two main reservoirs (A1 and A2) which contain bulk of the hydrocarbon in the Robi-1 field were identified, analyzed and evaluated. Attribute constrained reservoir models that capture possible structural and petrophysical uncertainties away from the well were generated to estimate hydrocarbon reserves as well as to determine optimal well placement. Reservoir structural models indicate that non-crossing East-West striking faults control the structural architecture, sealing the hydrocarbon fluids to the northern and southwestern part of the reservoir. Petrophysical results also show that both reservoirs have the comparable mean porosity and hydrocarbon saturation. Moreover, attribute analysis suggests that the northwestern region near reservoir A1 has a good hydrocarbon saturation and high porosity. The resulting models have assisted in proposing a deviated well to target the oil rim at A1 and the unknown hydrocarbon at A2.