The Niger Delta basin is dominated by shoreface deposits although tidal and estuarine channel deposits are typical. While reservoir modelling, HCIIP assessment, development strategy and placement of wells are commonly understood to be underpinned by sand distribution, there might have been a common tendency to apply a shoreface mindset in the channel reservoir settings. A methodologicalgeological understanding of channelized sand-bodies, their distribution and development underpinned by the integration of seismic and well data is therefore critical to optimal hydrocarbon maturation and development. The Eureka X7000 reservoir interpreted as channel sands from well logs of REKA-001 and mapped consistently on reflectivity data, suggested good sand development across the structure. Subsequent REKA-002 and REKA-003 flank wells results, resulted in a suprise in sand development, and a resultant reduction in HCIIP and reserves, highlighting blindspots that could have beenmitigated by the integration of acoustic impedance seismic volume, log data and realistic conceptual model scenarios of the reservoir. REKA-001 penetrated a channel complex 94 ft thick within the Eureka X7000 reservoir comprising three individual channel units~ 30 ft thick. Therefore, the reservoir was thought to be a channel complex with a maximum width of 2km comprising of series of individual channels with a width/thickness ratio of 66:1 based on REKA-001 results and existing analogues. This model would imply very good sand development with high NTG in the reservoir. REKA-002 was planned (1.6km away from REKA-001)as an appraisal/development well as part of the initial field development plan on the eastern flank of the structure. Post-drill assessment of the well results showed that the REKA-002 well penetrated the channel sand deposit sub-optimally and poorly developed which translated to a reduction in hydrocarbon volumes and in general well promise for the reservoir. The current estimated GIIP for X7000 reservoir is 169 Bscf some55% less than the pre-drill volumes of 376 Bscf. The REKA-002 well result on the X7000 is discussed to highlight the pre-drill geological evaluation pit-falls based on available well data and post-drill integration of quantitative seismic data, facies/property and sequence stratigrahic modelling approach to provide lessons for future field development plans.

There is general awareness of the importance of transfer accommodation faults towards controlling sediment dispersal, migration and hydrocarbon trapping in the deep-water thrust belt of Niger delta., These types of faults, although less understood, are also active in the onshore extensional part of the basin, where they can also exert important controls in sediment transport and/or reservoir geometry. These faults act as transfer mechanisms between major growth faults and provide a mechanical way to "accommodate" the non-orthogonal gravitational deformation. Although seismically we often map one single fault plane, these faults are more complex and could have a series of strands, which are often below seismic resolution. The strands from transfer faults could also control deposition as they act as barriers that hold back sedimentation helping to delineate the depocentre on the hanging wall (HW) of the main normal fault. A gas well targeting an accumulation on the footwall (FW) of a major growth fault, missed its target by 149 ft. Using innovative "in house" processing technology, 3D PSDM data showed that the new well was drilled between two small crestal collapse E-W normal faults, which are limited to the east by a strand of a major NNE-SSW transfer fault. This paper highlights the results of the new seismic interpretation, which looked at the geometry of the transfer fault in more detail and concluded that the interaction between the crestal collapse faults and the strands of the transfer system were important in the structural configuration of the target reservoir. This type of approach is useful in areas of fault-fault intersection or poor quality seismic data where the presence of smaller scale accommodation faults can significantly affect depth prognosis during well planning and static volume computation.