Seismic Attributes Mapping and 3D Static Modeling of Reservoirs within “OYA” Field, Offshore Depobelt, Niger Delta Sedimentary Basin, Nigeria

Abstract

An integrated 3D seismic data, checkshot data and suite of well logs for nine wells in “OYA” field, Offshore, Niger Delta were analyzed for reservoir characterization, 3D static modeling and volumetric analysis. This study is majorly in two folds: the first focuses on the application of 3D static model by incorporating all the geologic characteristics within subsurface volume that are relatively stable over long periods of time for optimization and development of hydrocarbon potentials in “OYA” field while the use of seismic attributes to map and identify new prospects that can be possibly explored in the same field. Geological structural and property models (net to gross, porosity, permeability, and water saturation) were distributed stochastically within the constructed 3D grid using the method of Sequential Gaussian Simulation algorithms. Depth structural maps and seismic attribute maps generated shows the trapping mechanisms to be a fault assisted anticlinal closure and four way closures while new hydrocarbon prospects were delineated respectively. The result (output) of the 3D static model was used to carry out volumetric analysis which divided the three reservoirs (Sand 1, 2 and 3) into two zones; the first zone [sand 1- sand 2(surface depths)] with a STOIIP of 4.93344*106 Stock tank barrel of recoverable oil while the second zone [sand 2-sand 3 (surface depths)] have a STOIIP value of 500369*106 Stock tank barrel of recoverable oil. This research work has demonstrated how new hydrocarbon prospects can be further explored in the field. 3D static geologic models and volumetric analysis of evaluated reservoirs in the already drilled wells shows evidence of good hydrocarbon yield in the field of study.