Title: Enhanced Hydrocarbon Reservoir Delineation and Evaluation using AVO Reconnaissance studies in the Coastal Swamp of Niger Delta
Authors: Dagogo
Tamunonengiyeofori
Balogun
Ayomide Olumide
Volume: 10
Issue: 5
Pages: 226-233
Publication Date: 2026/05/28
Abstract:
Amplitude versus offset (AVO) analysis was applied as a reconnaissance tool, in this field of the coastal swamp depobelt of the Niger Delta, known for its lithofacies diversity and heterogeneous reservoirs, which resulted from multi-process influenced depositional environments and abnormal pressures. Some of the specific challenges encountered in the field include paucity of data and geologic complexity. The objective was to effectively delineate and characterize reservoirs and highlight prospects with high fidelity, particularly for one of the two (2) wells, W-4, which had no neutron porosity log and the available resistivity log did not show any reliable contrast to indicate hydrocarbon saturation at depth intervals that are considered charged in the other well. AVO scenario modeling showed that density and Poisson's ratio were more sensitive to pore fluid changes. The modeled logs highlighted a high correlation between the in-situ and 100% oil saturation, AVO curve and intercept-gradient plots done on generated synthetics revealed the sands to exhibit class 1 and 2p anomalies. Further petrophysical evaluation showed the sands of interest to have excellent reservoir properties, with porosities, net to gross and hydrocarbon saturation having average values of 26%, 70% and 57% respectively. This finding underscores the robustness of AVO analysis to enhance reservoir delineation and evaluation when applied at different stages of the exploration workflow.