The Prospectivity and Exploration Potential of Onshore Slope Fan Play, Niger Delta Basin, Nigeria

The need to replace oil/gas production reserves cannot be over-emphasized, especially in areas with production facilities and ullage capacity, as in the onshore setting of the Niger Delta, where familiar and proven play types have been heavily drilled and tested. Any successful exploration effort on the onshore Eocene-Oligocene Slope Fan play, should have attractive economics, provided reserve replacement volumes and cost effective analogue for better understanding of such play exists in present-day deep-water setting. These views necessitated the present study. The Slope Fan objective was defined by mapping seismic reflector terminations, application of seismic and sequence stratigraphic principles, to well and 3D data set in the Eastern part of the Northern Depobelt. This provided a better understanding of the reservoir, seal facies and related Geologic risks. The MIN, MAX and RMS attribute extractions of the mapped fan body were used to highlight the internal architecture and constrain quality sand-prone “sweet-spot” areas. Further analysis of the observed “Mound Deposit” geometry, revealed different unconnected stratigraphic “Deposition Lobes”, separated by thin shale levels and the overall stacking pattern. In this study, the Geologic Chance Of Success (GCOS) was 0.14-0.35 for the “sweet spot” areas, where the P50 risked resources range of 2-36 MBOE was calculated. These exploration data should support a Near Field Wildcat strategy and development program. The methodology and technical understanding from this effort, have been applied to an opportunity which is currently producing some 3000 BOPD and at 35 Km from a high water-cut Field in the Niger Delta Basin.