Reservoir Facies Heterogeneity Characterization: An Implication for Carbon Dioxide (CO2) Geo Sequestration Site Selection in the Akos Field Coastal Swamps Niger Delta

Abstract

Abstract This study focuses on the characterization of the structural and stratigraphic heterogeneity of Cretaceous reservoirs within the Akos field using integrated seismic and well logs datasets. The main objective is to identify potential reservoir sands for effective CO2 sequestration. Using petrophysical analysis, fault modeling, and geostatistical methods, a comprehensive 3D facies and petrophysical property model was developed to understand the distribution of reservoir heterogeneity and its potential impact on CO2 sequestration. The study then utilizes the constructed 3D static model to analyze the spatio-temporal distribution of reservoir properties, particularly facies, porosity, and permeability, and their predictive influence on the performance of CO2 geo-sequestration projects in the reservoir case study. The performance of the projects was assessed using metrics such as storage capacity and fluid flow behavior during sequestration. This research investigated reservoir formation heterogeneity and its potential for CO2 sequestration in the field. The analysis focuses on four deep reservoirs within the Agbada Formation (Reservoir G, H, I, and J). These reservoirs have shown varying porosity, permeability, and water saturation across the field. The results obtained from this study indicate that the Akos field exhibits relatively high porosity and permeability reservoirs with moderate heterogeneity, and high structural stability, which makes it a suitable and low-risk area for CO2 sequestration, utilization, and storage (CCUS).