Petrophysical Evaluation and Volumetric Estimation of Hydrocarbon Reserves in Otio Field, Niger Delta

Abstract

This research presents a comprehensive petrophysical evaluation of the Otio Field, located in the
onshore Niger Delta Basin, with a focus on characterizing hydrocarbon-bearing reservoirs. A multidisciplinary
approach was employed, integrating well log data and seismic interpretation to analyze key petrophysical
parameters across five hydrocarbon-bearing horizons (Sands D, E1, E2, H, and J). The petrophysical analysis
revealed porosity values ranging from 18% to 27%, water saturation between 20% and 31%, and Net-To-Gross
(NTG) ratios of 59% to 96%. These parameters were used to evaluate the reservoir quality and hydrocarbon
potential of each horizon. The structural framework of the field was also evaluated, with 16 faults mapped,
including major trapping structures F6 and F7. Time and depth structure maps were generated for each horizon,
enabling accurate volume estimations. The results indicate that the North-Eastern prospect is the most promising,
particularly in Sand E2, which exhibits the highest hydrocarbon volume in place. This study provides valuable
insights into the petrophysical properties of the Otio Field reservoirs, offering a basis for prospect ranking and
guiding future exploration efforts.

Keywords: Petrophysical analysis, volumetric estimation, hydrocarbon reserves, well logs, seismic interpretation.