Depositional environment and reservoir flow unit characterization of Okogbe Field, onshore Niger Delta, Nigeria

Abstract

Okogbe Field is an Onshore field located in the South-Eastern part of the Niger Delta. Depositional environments and flow unit characteristics of Okogbe Field reservoirs have been evaluated using wireline log data. Four (4) wells from the Okogbe Field were used in this study to delineate the stratigraphic positions of the reservoir flow zones, depositional environments of the reservoir sand bodies, their depositional trends and geometry. In addition, evaluated the reservoir petrophysical properties and characterize the reservoir flow units (storage capacity and flow capability assessment. The Stratigraphic Modified Lorenz (SML) plot (a cross plot of Cumulative Flow Capacity versus Cumulative Storage Capability from porosity and permeability data) was applied in this study. The results, show that the porosity is 22% to 34% and permeability is 1400mD to 2883mD indicating excellent reservoir quality for the field. Well F-021 has the best porosity (34%), permeability (2883.03mD) and lowest water saturation (26%) suggesting highest reservoir productivity. Twenty-four (24) flow units based on the Stratigraphic Modified Lorenz (SML) plot and gamma log motifs have been identified and indicates that the reservoirs have similar flow patterns. The dominant depositional setting of the study area is shallow marine - shoreface and beach environments. The depositional environmental model and reservoir flow unit characterization of Okogbe Field has been carried out which may serve as a control in predicting flow properties in the other unexplored project areas.

Keywords: Flow Unit Characterization, Depositional Environment, Reservoir Sand Bodies Okogbe Field, Niger Delta