Prediction of Reservoir Performance of Moby Field, Niger Delta Basin using Integrated Facies and Petrophysical Analyses.

This study investigates the influence of depositional facies on reservoir quality and performance in the Moby Field, a mature and depleting hydrocarbon field in the Niger Delta Basin. The study integrates well-log interpretation and three-dimensional (3D) seismic facies analysis to characterize the depositional facies and evaluate their control on reservoir petrophysical properties. Five well-log subfacies were identified and grouped into three major facies associations: delta front, tidal flat, and shoreface. The delta front association comprises distributary channel and distributary mouth bar subfacies, while the tidal flat association consists of intertidal and subtidal subfacies. The storm-dominated shelf subfacies represents the shoreface association. Four seismic facies types (D, CBH, CBHL, and BL) were recognized and correlated with the identified well-log facies. The D seismic facies, corresponding to the delta front environment, exhibits the highest sand content and represents the most favourable exploration target. The depositional setting is interpreted as marginal to shallow marine. Nine reservoirs (H1–H9) were delineated, with H1–H2 associated with delta front deposits, H3–H6 with intertidal deposits, and H7–H9 with subtidal deposits. Petrophysical evaluation indicates that H1 and H2 possess the best reservoir properties, followed by H7–H9, while H3–H6 exhibit comparatively poorer reservoir quality. These variations are attributed primarily to differences in depositional conditions and facies architecture, which exert significant control on reservoir heterogeneity and petrophysical properties. The findings demonstrate that integrated well-log and 3D seismic facies analysis provides an effective framework for predicting reservoir quality and improving reservoir characterization, performance prediction, and management in mature Niger Delta fields.