Professional Review of Reservoir Characterisation Workflows for Maximising Recovery from the Paleocene Deepwater Turbidite Sands of the Nigerian Equatorial Margin

Paleocene deepwater turbidite sands along the Nigerian Equatorial Margin host multi-hundred-million-barrel oil accumulations that require sophisticated reservoir characterisation workflows to achieve maximum field recovery. This study professionally reviews state-of-practice reservoir characterisation workflows applicable to these reservoirs, drawing on published field development studies from the Bonga, Erha, and Egina deepwater fields operated by Shell, ExxonMobil, and Total Energies, respectively. The review covers the full characterisation workflow from seismic facies analysis through to dynamic model conditioning and production history matching. Specific methodological advances evaluated include full-waveform inversion for acoustic impedance volumes, rock physics template construction for fluid substitution uncertainty quantification, and ensemble-based history matching for dynamic uncertainty reduction. Comparison of characterisation workflow outputs from each reviewed field reveals that wells drilled using reservoir models incorporating ensemble-based history matching achieved a 23 percent improvement in primary recovery factor prediction accuracy at the ten-year production mark compared to models calibrated by conventional manual history matching. The study identifies remaining characterisation gaps common to Nigerian deepwater turbidite fields, particularly in the quantification of sub-seismic baffles and barriers that control sweep efficiency at the inter-well scale. Recommendations are provided for data acquisition priorities in new deepwater appraisal programmes targeting the Paleocene interval. Keywords: reservoir characterisation, deepwater turbidite, Nigerian Equatorial Margin, history matching, recovery maximisation.