Screening-Level Deterministic Estimates of Fault-Controlled Reservoir Prospects in the Mag Field, Niger Delta Basin

Abstract

This study presents an integrated seismic interpretation and deterministic volumetric screening of fault-controlled reservoir prospects in the MAG Field, shallow offshore western Niger Delta Basin, Nigeria. The study reassessed the field’s structural framework, calibrated reservoir markers to seismic reflections, generated time and depth structural maps, and identified additional hydrocarbon opportunities within the limits of the available dataset. The dataset comprised seventeen 2D seismic lines, referenced 3D seismic information, and well data from MAG-01 and MAG-02. Review of the seismic coverage showed that the available 3D data do not extend across the MAG well locations, limiting their direct use for detailed reservoir-scale volumetric evaluation. Consequently, the nearest 3D seismic line was integrated with the 2D seismic framework to provide structural context. Well-to-seismic calibration using MAG-01 produced a fair-to-good tie, with a correlation coefficient of approximately 0.58. A second-order polynomial time-depth relationship derived from MAG-01 was applied for depth conversion. Interpretation indicates that the MAG Field is a NW-SE-trending collapse-crest rollover anticline bounded by a major northern growth fault and a southern antithetic fault. Three reservoir intervals, D-5 sand, E sand, and E-1 sand, were mapped. Deterministic screening identified five reservoir-prospect combinations, with the largest estimates in the E-1 East and E Sand North-East prospects. The results support preliminary reassessment of MAG Field prospectivity but require improved seismic coverage, velocity control, and uncertainty-based volumetric evaluation before prospect maturation.